International Journal of Molecular Sciences

734 KiB

Open AccessArticle

Diffusivity Maximum in a Reentrant Nematic Phase

by Tillmann Stieger, Marco G. Mazza and Martin Schoen

Int. J. Mol. Sci. 2012, 13(6), 7854-7871; https://doi.org/10.3390/ijms13067854 - 21 Jun 2012

Cited by 4 | Viewed by 6828

We report molecular dynamics simulations of confined liquid crystals using the Gay–Berne–Kihara model. Upon isobaric cooling, the standard sequence of isotropic–nematic–smectic A phase transitions is found. Upon further cooling a reentrant nematic phase occurs. We investigate the temperature dependence of the self-diffusion coefficient [...] Read more.

We report molecular dynamics simulations of confined liquid crystals using the Gay–Berne–Kihara model. Upon isobaric cooling, the standard sequence of isotropic–nematic–smectic A phase transitions is found. Upon further cooling a reentrant nematic phase occurs. We investigate the temperature dependence of the self-diffusion coefficient of the fluid in the nematic, smectic and reentrant nematic phases. We find a maximum in diffusivity upon isobaric cooling. Diffusion increases dramatically in the reentrant phase due to the high orientational molecular order. As the temperature is lowered, the diffusion coefficient follows an Arrhenius behavior. The activation energy of the reentrant phase is found in reasonable agreement with the reported experimental data. We discuss how repulsive interactions may be the underlying mechanism that could explain the occurrence of reentrant nematic behavior for polar and non-polar molecules. Full article

(This article belongs to the Special Issue Self-Assembled Soft Matter Nanostructures at Interfaces)

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189 KiB

Open AccessReview

Mitogen-Activated Protein (MAP) Kinases in Plant Metal Stress: Regulation and Responses in Comparison to Other Biotic and Abiotic Stresses

by Kelly Opdenakker, Tony Remans, Jaco Vangronsveld and Ann Cuypers

Int. J. Mol. Sci. 2012, 13(6), 7828-7853; https://doi.org/10.3390/ijms13067828 - 21 Jun 2012

Cited by 116 | Viewed by 11198

Abstract

Exposure of plants to toxic concentrations of metals leads to disruption of the cellular redox status followed by an accumulation of reactive oxygen species (ROS). ROS, like hydrogen peroxide, can act as signaling molecules in the cell and induce signaling via mitogen-activated protein [...] Read more.

Exposure of plants to toxic concentrations of metals leads to disruption of the cellular redox status followed by an accumulation of reactive oxygen species (ROS). ROS, like hydrogen peroxide, can act as signaling molecules in the cell and induce signaling via mitogen-activated protein kinase (MAPK) cascades. MAPK cascades are evolutionary conserved signal transduction modules, able to convert extracellular signals to appropriate cellular responses. In this review, our current understanding about MAPK signaling in plant metal stress is discussed. However, this knowledge is scarce compared to research into the role of MAPK signaling in the case of other abiotic and biotic stresses. ROS production is a common response induced by different stresses and undiscovered analogies may exist with metal stress. Therefore, further attention is given to MAPK signaling in other biotic and abiotic stresses and its interplay with other signaling pathways to create a framework in which the involvement of MAPK signaling in metal stress may be studied. Full article

(This article belongs to the Special Issue Advances in Molecular Plant Biology)

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Open AccessReview

Spatial Simulations in Systems Biology: From Molecules to Cells

by Michael Klann and Heinz Koeppl

Int. J. Mol. Sci. 2012, 13(6), 7798-7827; https://doi.org/10.3390/ijms13067798 - 21 Jun 2012

Cited by 46 | Viewed by 9813

Abstract

Cells are highly organized objects containing millions of molecules. Each biomolecule has a specific shape in order to interact with others in the complex machinery. Spatial dynamics emerge in this system on length and time scales which can not yet be modeled with [...] Read more.

Cells are highly organized objects containing millions of molecules. Each biomolecule has a specific shape in order to interact with others in the complex machinery. Spatial dynamics emerge in this system on length and time scales which can not yet be modeled with full atomic detail. This review gives an overview of methods which can be used to simulate the complete cell at least with molecular detail, especially Brownian dynamics simulations. Such simulations require correct implementation of the diffusion-controlled reaction scheme occurring on this level. Implementations and applications of spatial simulations are presented, and finally it is discussed how the atomic level can be included for instance in multi-scale simulation methods. Full article

(This article belongs to the Special Issue Advances in Biomolecular Simulation)

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266 KiB

Open AccessArticle

Plasma Depolymerization of Chitosan in the Presence of Hydrogen Peroxide

by Fengming Ma, Zhenyu Wang, Haitian Zhao and Shuangqi Tian

Int. J. Mol. Sci. 2012, 13(6), 7788-7797; https://doi.org/10.3390/ijms13067788 - 21 Jun 2012

Cited by 32 | Viewed by 7357

Abstract

The depolymerization of chitosan by plasma in the presence of hydrogen peroxide (H₂O₂) was investigated. The efficiency of the depolymerization was demonstrated by means of determination of viscosity-average molecular weight and gel permeation chromatography (GPC). The structure of the [...] Read more.

The depolymerization of chitosan by plasma in the presence of hydrogen peroxide (H₂O₂) was investigated. The efficiency of the depolymerization was demonstrated by means of determination of viscosity-average molecular weight and gel permeation chromatography (GPC). The structure of the depolymerized chitosan was characterized by Fourier-transform infrared spectra (FT-IR), ultraviolet spectra (UV) and X-ray diffraction (XRD). The results showed that chitosan can be effectively degradated by plasma in the presence of H₂O₂. The chemical structure of the depolymerized chitosan was not obviously modified. The combined plasma/H₂O₂ method is significantly efficient for scale-up manufacturing of low molecular weight chitosan. Full article

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447 KiB

Open AccessArticle

Polydatin Attenuates Hypoxic Pulmonary Hypertension and Reverses Remodeling through Protein Kinase C Mechanisms

by Qing Miao, Xiao-Peng Shi, Ming-Xiang Ye, Jin Zhang, Shan Miao, Si-Wang Wang, Bo Li, Xiu-Xiu Jiang, Song Zhang, Nan Hu, Juan Li and Jian Zhang

Int. J. Mol. Sci. 2012, 13(6), 7776-7787; https://doi.org/10.3390/ijms13067776 - 21 Jun 2012

Cited by 20 | Viewed by 7112

Abstract

Hypoxic pulmonary hypertension is a life-threatening emergency if untreated. Consistent pulmonary hypertension also leads to arteries and ventricular remodeling. The clinical therapeutic strategy for pulmonary hypertension and the corresponding remodeling mainly interacts with NO, angiotensin II (Ang II) and elevated endothelin (ET) targets. [...] Read more.

Hypoxic pulmonary hypertension is a life-threatening emergency if untreated. Consistent pulmonary hypertension also leads to arteries and ventricular remodeling. The clinical therapeutic strategy for pulmonary hypertension and the corresponding remodeling mainly interacts with NO, angiotensin II (Ang II) and elevated endothelin (ET) targets. In the present study, we evaluated the effects of polydatin on hypoxia-induced pulmonary hypertension. It was observed that polydatin attenuated hypoxic pulmonary hypertension, reversed remodeling, and regulated NO, Ang II, ET contents in the serum and lung samples. However, forced activation of PKC signaling by its selective activator thymeleatoxin (THX) could abate the effects of polydatain. These results suggest that polydatin might be a promising candidate for hypoxic pulmonary treatment through interaction with PKC mechanisms. Full article

(This article belongs to the Section Biochemistry)

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634 KiB

Open AccessArticle

Preparation of Porous Scaffolds from Silk Fibroin Extracted from the Silk Gland of Bombyx mori (B. mori)

by Mingying Yang, Yajun Shuai, Wen He, Sijia Min and Liangjun Zhu

Int. J. Mol. Sci. 2012, 13(6), 7762-7775; https://doi.org/10.3390/ijms13067762 - 21 Jun 2012

Cited by 33 | Viewed by 9297

Abstract

In order to use a simple and ecofriendly method to prepare porous silk scaffolds, aqueous silk fibroin solution (ASF) was extracted from silk gland of 7-day-old fifth instar larvae of Bombyx mori (B. mori). SDS-page analysis indicated that the obtained fibroin [...] Read more.

In order to use a simple and ecofriendly method to prepare porous silk scaffolds, aqueous silk fibroin solution (ASF) was extracted from silk gland of 7-day-old fifth instar larvae of Bombyx mori (B. mori). SDS-page analysis indicated that the obtained fibroin had a molecular weight higher than 200 kDa. The fabrication of porous scaffolds from ASF was achieved by using the freeze-drying method. The pore of porous scaffolds is homogenous and tends to become smaller with an increase in the concentration of ASF. Conversely, the porosity is decreased. The porous scaffolds show impressive compressive strength which can be as high as 6.9 ± 0.4 MPa. Furthermore, ASF has high cell adhesion and growth activity. It also exhibits high ALP activity. This implies that porous scaffolds prepared from ASF have biocompatibility. Therefore, the porous scaffolds prepared in this study have potential application in tissue engineering due to the impressive compressive strength and biocompatibility. Full article

(This article belongs to the Section Materials Science)

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Open AccessReview

Clinical Neuroprotective Drugs for Treatment and Prevention of Stroke

by Kiyoshi Kikuchi, Hisaaki Uchikado, Motohiro Morioka, Yoshinaka Murai and Eiichiro Tanaka

Int. J. Mol. Sci. 2012, 13(6), 7739-7761; https://doi.org/10.3390/ijms13067739 - 21 Jun 2012

Cited by 21 | Viewed by 8951

Abstract

Stroke is an enormous public health problem with an imperative need for more effective therapies. In therapies for ischemic stroke, tissue plasminogen activators, antiplatelet agents and anticoagulants are used mainly for their antithrombotic effects. However, free radical scavengers, minocycline and growth factors have [...] Read more.

Stroke is an enormous public health problem with an imperative need for more effective therapies. In therapies for ischemic stroke, tissue plasminogen activators, antiplatelet agents and anticoagulants are used mainly for their antithrombotic effects. However, free radical scavengers, minocycline and growth factors have shown neuroprotective effects in the treatment of stroke, while antihypertensive drugs, lipid-lowering drugs and hypoglycemic drugs have shown beneficial effects for the prevention of stroke. In the present review, we evaluate the treatment and prevention of stroke in light of clinical studies and discuss new anti-stroke effects other than the main effects of drugs, focusing on optimal pharmacotherapy. Full article

(This article belongs to the Special Issue Neuroprotective Strategies 2012)

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Open AccessArticle

Effects of Methylmercury Contained in a Diet Mimicking the Wayana Amerindians Contamination through Fish Consumption: Mercury Accumulation, Metallothionein Induction, Gene Expression Variations, and Role of the Chemokine CCL2

by Jean-Paul Bourdineaud, Muriel Laclau, Régine Maury-Brachet, Patrice Gonzalez, Magalie Baudrimont, Nathalie Mesmer-Dudons, Masatake Fujimura, Aline Marighetto, David Godefroy, William Rostène and Daniel Brèthes

Int. J. Mol. Sci. 2012, 13(6), 7710-7738; https://doi.org/10.3390/ijms13067710 - 21 Jun 2012

Cited by 14 | Viewed by 7328

Abstract

Methylmercury (MeHg) is a potent neurotoxin, and human beings are mainly exposed to this pollutant through fish consumption. We addressed the question of whether a diet mimicking the fish consumption of Wayanas Amerindians from French Guiana could result in observable adverse effects in [...] Read more.

Methylmercury (MeHg) is a potent neurotoxin, and human beings are mainly exposed to this pollutant through fish consumption. We addressed the question of whether a diet mimicking the fish consumption of Wayanas Amerindians from French Guiana could result in observable adverse effects in mice. Wayanas adult men are subjected to a mean mercurial dose of 7 g Hg/week/kg of body weight. We decided to supplement a vegetarian-based mice diet with 0.1% of lyophilized Hoplias aimara fish, which Wayanas are fond of and equivalent to the same dose as that afflicting the Wayanas Amerindians. Total mercury contents were 1.4 ± 0.2 and 5.4 ± 0.5 ng Hg/g of food pellets for the control and aimara diets, respectively. After 14 months of exposure, the body parts and tissues displaying the highest mercury concentration on a dry weight (dw) basis were hair (733 ng/g) and kidney (511 ng/g), followed by the liver (77 ng/g). Surprisingly, despite the fact that MeHg is a neurotoxic compound, the brain accumulated low levels of mercury (35 ng/g in the cortex). The metallothionein (MT) protein concentration only increased in those tissues (kidney, muscles) in which MeHg demethylation had occurred. This can be taken as a molecular sign of divalent mercurial contamination since only Hg²⁺ has been reported yet to induce MT accumulation in contaminated tissues. The suppression of the synthesis of the chemokine CCL2 in the corresponding knockout (KO) mice resulted in important changes in gene expression patterns in the liver and brain. After three months of exposure to an aimara-containing diet, eight of 10 genes selected (Sdhb, Cytb, Cox1, Sod1, Sod2, Mt2, Mdr1a and Bax) were repressed in wild-type mice liver whereas none presented a differential expression in KO Ccl2⁻^/⁻ mice. In the wild-type mice brain, six of 12 genes selected (Cytb, Cox1, Sod1, Sod2, Mdr1a and Bax) presented a stimulated expression, whereas all remained at the basal level of expression in KO Ccl2⁻^/⁻ mice. In the liver of aimara-fed mice, histological alterations were observed for an accumulated mercury concentration as low as 32 ng/g, dw, and metal deposits were observed within the cytoplasm of hepatic cells. Full article

(This article belongs to the Special Issue Molecular Mechanisms of Organ-Specific Toxicity)

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428 KiB

Open AccessArticle

The Role of PPARα in Metformin-Induced Attenuation of Mitochondrial Dysfunction in Acute Cardiac Ischemia/Reperfusion in Rats

by Giselle Barreto-Torres, Rebecca Parodi-Rullán and Sabzali Javadov

Int. J. Mol. Sci. 2012, 13(6), 7694-7709; https://doi.org/10.3390/ijms13067694 - 21 Jun 2012

Cited by 55 | Viewed by 7385

Abstract

Metformin, an anti-diabetic drug, exerts cardioprotection against ischemia-reperfusion (IR) through the activation of AMPK. However, the molecular mechanisms underlying these beneficial effects remain elusive. In this study, we examined the role of PPARα in mediating cardioprotective effects of metformin on mitochondria. Hearts of [...] Read more.

Metformin, an anti-diabetic drug, exerts cardioprotection against ischemia-reperfusion (IR) through the activation of AMPK. However, the molecular mechanisms underlying these beneficial effects remain elusive. In this study, we examined the role of PPARα in mediating cardioprotective effects of metformin on mitochondria. Hearts of male Sprague-Dawley rats perfused by Langendorff were subjected to IR in the presence or absence of metformin and the PPARα inhibitor, GW6471. IR reduced cardiac function and compromised the structural integrity of cardiac cells evidenced by increased LDH release from the hearts. In addition, IR induced mitochondrial dysfunction as evidenced by reduced respiration and increased mitochondrial permeability transition pore (PTP) opening. However, metformin-treated hearts demonstrated improved post-ischemic recovery of cardiac function and reduced cell death that were associated with increased state 3 respiration at complexes I and II (by 27% and 32%, respectively, both p < 0.05) and decreased PTP opening (by 27%, p < 0.05) compared to untreated hearts. The protective effects of metformin on cardiac function and mitochondria were blocked by GW6471. Thus, our results demonstrate that inhibition of PPARα attenuates the beneficial effects of metformin on mitochondria in acute IR. Full article

(This article belongs to the Section Biochemistry)

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970 KiB

Open AccessArticle

Proteomic Analysis of Cerebrospinal Fluid in a Fulminant Case of Multiple Sclerosis

by Judit Füvesi, Jörg Hanrieder, Krisztina Bencsik, Cecilia Rajda, S. Krisztián Kovács, László Kaizer, Sándor Beniczky, László Vécsei and Jonas Bergquist

Int. J. Mol. Sci. 2012, 13(6), 7676-7693; https://doi.org/10.3390/ijms13067676 - 21 Jun 2012

Cited by 27 | Viewed by 8899

Abstract

Multiple Sclerosis (MS) is a chronic disease, but in rare fulminant cases rapid progression may lead to death shortly after diagnosis. Currently there is no diagnostic test to predict disease course. The aim of this study was to identify potential biomarkers/proteins related to [...] Read more.

Multiple Sclerosis (MS) is a chronic disease, but in rare fulminant cases rapid progression may lead to death shortly after diagnosis. Currently there is no diagnostic test to predict disease course. The aim of this study was to identify potential biomarkers/proteins related to rapid progression. We present the case history of a 15-year-old male MS patient. Cerebrospinal fluid (CSF) was taken at diagnosis and at the time of rapid progression leading to the patient’s death. Using isobaric tag labeling and nanoflow liquid chromatography in conjunction with matrix assisted laser desorption/ionization time of flight tandem mass spectrometry we quantitatively analyzed the protein content of two CSF samples from the patient with fulminant MS as well as one relapsing-remitting (RR) MS patient and one control headache patient, whose CSF analysis was normal. Seventy-eight proteins were identified and seven proteins were found to be more abundant in both fulminant MS samples but not in the RR MS sample compared to the control. These proteins are involved in the immune response, blood coagulation, cell proliferation and cell adhesion. In conclusion, in this pilot study we were able to show differences in the CSF proteome of a rapidly progressing MS patient compared to a more typical clinical form of MS and a control subject. Full article

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407 KiB

Open AccessArticle

Expression of Sox2 and Oct4 and Their Clinical Significance in Human Non-Small-Cell Lung Cancer

by Xinxin Li, Jinguang Wang, Zhiyun Xu, Aftab Ahmad, Encheng Li, Yuan Wang, Suli Qin and Qi Wang

Int. J. Mol. Sci. 2012, 13(6), 7663-7675; https://doi.org/10.3390/ijms13067663 - 21 Jun 2012

Cited by 91 | Viewed by 9526

Abstract

Sox2 and Oct4 are transcription factors with the characteristics of regulating self-renewal and differentiation of embryonic stem cell. The aim of this study was to detect the expression of Sox2 and Oct4 and analyze their clinical significance in human non-small-cell lung cancer (NSCLC). [...] Read more.

Sox2 and Oct4 are transcription factors with the characteristics of regulating self-renewal and differentiation of embryonic stem cell. The aim of this study was to detect the expression of Sox2 and Oct4 and analyze their clinical significance in human non-small-cell lung cancer (NSCLC). Expression of Sox2 and Oct4 were assayed in cancer tissues and their corresponding paracancerous tissues from 44 patients with NSCLC and 21 patients with benign tumors using immunohistochemistry, Western blot, reverse transcription polymerase chain reaction (RT-PCR). The correlation between the expression of Sox2 and Oct4 and tumor type, grade and prognosis and the utility of the two genes in discriminating between benign and malignant tumors were analyzed as well. The results showed that Sox2 and Oct4 positive staining was only seen in the nuclei of cancer cells but not in either the precancerous tissues or benign tumor tissues by immunohistochemistry (p < 0.01). Furthermore, in the lung cancer tissue, the positive rate for Sox2 and Oct4 was 70.5% and 54.5%, respectively. Meanwhile, clinicopathological correlations showed that the Oct4 expression level was significantly associated with poorer differentiation and higher TNM stage of the cancer (p < 0.05). Western blot and RT-PCR analysis showed similar results to immunohistochemistry. Follow-up analysis revealed that expression of Oct4 was significantly associated with poor prognosis of lung cancer. The conclusion is that Sox2 and Oct4 may act as the promising unit markers in directing NSCLC diagnosis and therapy. Also, Oct4 can be regarded as a novel predictor of poor prognosis for NSCLC patients undergoing resection. Full article

(This article belongs to the Special Issue Advances in Molecular Oncology (special issue))

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Open AccessArticle

Supercritical Fluid Extraction of Eucalyptus globulus Bark—A Promising Approach for Triterpenoid Production

by Rui M. A. Domingues, Eduardo L. G. Oliveira, Carmen S. R. Freire, Ricardo M. Couto, Pedro C. Simões, Carlos P. Neto, Armando J. D. Silvestre and Carlos M. Silva

Int. J. Mol. Sci. 2012, 13(6), 7648-7662; https://doi.org/10.3390/ijms13067648 - 21 Jun 2012

Cited by 54 | Viewed by 9845

Abstract

Eucalyptus bark contains significant amounts of triterpenoids with demonstrated bioactivity, namely triterpenic acids and their acetyl derivatives (ursolic, betulinic, oleanolic, betulonic, 3-acetylursolic, and 3-acetyloleanolic acids). In this work, the supercritical fluid extraction (SFE) of Eucalyptus globulus deciduous bark was carried out with pure [...] Read more.

Eucalyptus bark contains significant amounts of triterpenoids with demonstrated bioactivity, namely triterpenic acids and their acetyl derivatives (ursolic, betulinic, oleanolic, betulonic, 3-acetylursolic, and 3-acetyloleanolic acids). In this work, the supercritical fluid extraction (SFE) of Eucalyptus globulus deciduous bark was carried out with pure and modified carbon dioxide to recover this fraction, and the results were compared with those obtained by Soxhlet extraction with dichloromethane. The effects of pressure (100–200 bar), co-solvent (ethanol) content (0, 5 and 8% wt), and multistep operation were studied in order to evaluate the applicability of SFE for their selective and efficient production. The individual extraction curves of the main families of compounds were measured, and the extracts analyzed by GC-MS. Results pointed out the influence of pressure and the important role played by the co-solvent. Ethanol can be used with advantage, since its effect is more important than increasing pressure by several tens of bar. At 160 bar and 40 °C, the introduction of 8% (wt) of ethanol greatly improves the yield of triterpenoids more than threefold. Full article

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Graphical abstract

241 KiB

Open AccessReview

WIP Remodeling Actin behind the Scenes: How WIP Reshapes Immune and Other Functions

by Elad Noy, Sophia Fried, Omri Matalon and Mira Barda-Saad

Int. J. Mol. Sci. 2012, 13(6), 7629-7647; https://doi.org/10.3390/ijms13067629 - 21 Jun 2012

Cited by 15 | Viewed by 7368

Abstract

Actin polymerization is a fundamental cellular process regulating immune cell functions and the immune response. The Wiskott-Aldrich syndrome protein (WASp) is an actin nucleation promoting factor, which is exclusively expressed in hematopoietic cells, where it plays a key regulatory role in cytoskeletal dynamics. [...] Read more.

Actin polymerization is a fundamental cellular process regulating immune cell functions and the immune response. The Wiskott-Aldrich syndrome protein (WASp) is an actin nucleation promoting factor, which is exclusively expressed in hematopoietic cells, where it plays a key regulatory role in cytoskeletal dynamics. WASp interacting protein (WIP) was first discovered as the binding partner of WASp, through the use of the yeast two hybrid system. WIP was later identified as a chaperone of WASp, necessary for its stability. Mutations occurring at the WASp homology 1 domain (WH1), which serves as the WIP binding site, were found to cause the Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT). WAS manifests as an immune deficiency characterized by eczema, thrombocytopenia, recurrent infections, and hematopoietic malignancies, demonstrating the importance of WIP for WASp complex formation and for a proper immune response. WIP deficiency was found to lead to different abnormalities in the activity of various lymphocytes, suggesting differential cell-dependent roles for WIP. Additionally, WIP deficiency causes cellular abnormalities not found in WASp-deficient cells, indicating that WIP fulfills roles beyond stabilizing WASp. Indeed, WIP was shown to interact with various binding partners, including the signaling proteins Nck, CrkL and cortactin. Recent studies have demonstrated that WIP also takes part in non immune cellular processes such as cancer invasion and metastasis, in addition to cell subversion by intracellular pathogens. Understanding of numerous functions of WIP can enhance our current understanding of activation and function of immune and other cell types. Full article

(This article belongs to the Special Issue Advances in Molecular Immunology)

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478 KiB

Open AccessArticle

Biodegradation Study of Microcrystalline Chitosan and Microcrystalline Chitosan/β-TCP Complex Composites

by Luciano Pighinelli, Magdalena Kucharska, Maria Wísniewska-Wrona, Bogdan Gruchała and Kinga Brzoza-Malczewska

Int. J. Mol. Sci. 2012, 13(6), 7617-7628; https://doi.org/10.3390/ijms13067617 - 21 Jun 2012

Cited by 12 | Viewed by 6967

Abstract

Bone repair or regeneration is a common and complicated clinical problem in orthopedic surgery. The importance of natural polymers, such as microcrystalline chitosan, and minerals such as HAp and β-TCP, has grown significantly over the last two decades due to their renewable and [...] Read more.

Bone repair or regeneration is a common and complicated clinical problem in orthopedic surgery. The importance of natural polymers, such as microcrystalline chitosan, and minerals such as HAp and β-TCP, has grown significantly over the last two decades due to their renewable and biodegradable source, increasing the knowledge and functionality of composites in technological and biomedical applications. This study compares the biodegradation process, bioactivity, structure, morphology, and mechanical properties of microcrystalline chitosan and microcrystalline chitosan/β-TCP complex; the latter according to the new method of preparation. The complex showed a homogeneous network structure with regular pores, good bioactivity, even after 60 days of conducting the hydrolytic and enzymatic degradation process, showing a bacteriostatic and bactericidal activity. The complex indicates that it could be used successfully as a base for implants and scaffolds production in orthopedic surgery. Full article

(This article belongs to the Special Issue Composite Materials in Skeletal Engineering)

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Open AccessCommunication

Ultrasound-Assisted Extraction of Syringin from the Bark of Ilex rotunda Thumb Using Response Surface Methodology

by Li-Chun Zhao, Ying He, Xin Deng, Xiang-Hua Xia, Jian Liang, Geng-Liang Yang, Wei Li and Hui Wang

Int. J. Mol. Sci. 2012, 13(6), 7607-7616; https://doi.org/10.3390/ijms13067607 - 20 Jun 2012

Cited by 22 | Viewed by 8031

Abstract

In this work, a rapid extraction method based on ultrasound-assisted extraction (UAE) of syringin from the bark of Ilex rotunda Thumb using response surface methodology (RSM) is described. The syringin was analyzed and quantified by high performance liquid chromatography coupled with UV detection [...] Read more.

In this work, a rapid extraction method based on ultrasound-assisted extraction (UAE) of syringin from the bark of Ilex rotunda Thumb using response surface methodology (RSM) is described. The syringin was analyzed and quantified by high performance liquid chromatography coupled with UV detection (HPLC-UV). The extraction solvent, extraction temperature and extraction time, the three main factors for UAE, were optimized with Box-Behnken design (BBD) to obtain the highest extraction efficiency. The optimal conditions were the use of a sonication frequency of 40 kHz, 65% methanol as the solvent, an extraction time of 30 min and an extraction temperature of 40 °C. Using these optimal conditions, the experimental values agreed closely with the predicted values. The analysis of variance (ANOVA) indicated a high goodness of model fit and the success of the RSM method for optimizing syringin extraction from the bark of I. rotunda. Full article

(This article belongs to the Section Biochemistry)

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Open AccessArticle

Density Functional Theory (DFT) Study of Edaravone Derivatives as Antioxidants

by Rosivaldo S. Borges, Auriekson N. Queiroz, Anna P. S. Mendes, Sanderson C. Araújo, Luiz C. S. França, Edna C. S. Franco, Walace G. Leal and Albérico B. F. Da Silva

Int. J. Mol. Sci. 2012, 13(6), 7594-7606; https://doi.org/10.3390/ijms13067594 - 20 Jun 2012

Cited by 24 | Viewed by 8562

Abstract

Quantum chemical calculations at the B3LYP/6–31G* level of theory were employed for the structure-activity relationship and prediction of the antioxidant activity of edaravone and structurally related derivatives using energy (E), ionization potential (IP), bond dissociation energy (BDE), and stabilization energies (∆ [...] Read more.

Quantum chemical calculations at the B3LYP/6–31G* level of theory were employed for the structure-activity relationship and prediction of the antioxidant activity of edaravone and structurally related derivatives using energy (E), ionization potential (IP), bond dissociation energy (BDE), and stabilization energies (∆E_iso). Spin density calculations were also performed for the proposed antioxidant activity mechanism. The electron abstraction is related to electron-donating groups (EDG) at position 3, decreasing the IP when compared to substitution at position 4. The hydrogen abstraction is related to electron-withdrawing groups (EDG) at position 4, decreasing the BDE_CH when compared to other substitutions, resulting in a better antioxidant activity. The unpaired electron formed by the hydrogen abstraction from the C–H group of the pyrazole ring is localized at 2, 4, and 6 positions. The highest scavenging activity prediction is related to the lowest contribution at the carbon atom. The likely mechanism is related to hydrogen transfer. It was found that antioxidant activity depends on the presence of EDG at the C₂ and C₄ positions and there is a correlation between IP and BDE. Our results identified three different classes of new derivatives more potent than edaravone. Full article

(This article belongs to the Special Issue Advances in Molecular Electronic Structure Calculations)

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Open AccessArticle

Isolation and Characterization of Simple Sequence Repeats (SSR) Markers from the Moss Genus Orthotrichum Using a Small Throughput Pyrosequencing Machine

by Jakub Sawicki, Mirosław Kwaśniewski, Monika Szczecińska, Karolina Chwiałkowska, Monika Milewicz and Vítězslav Plášek

Int. J. Mol. Sci. 2012, 13(6), 7586-7593; https://doi.org/10.3390/ijms13067586 - 19 Jun 2012

Cited by 8 | Viewed by 6629

Abstract

Here, we report the results of next-generation sequencing on the GS Junior system to identify a large number of microsatellites from the epiphytic moss Orthotrichum speciosum. Using a combination of a total (non-enrichment) genomic library and small-scale 454 pyrosequencing, we determined 5382 [...] Read more.

Here, we report the results of next-generation sequencing on the GS Junior system to identify a large number of microsatellites from the epiphytic moss Orthotrichum speciosum. Using a combination of a total (non-enrichment) genomic library and small-scale 454 pyrosequencing, we determined 5382 contigs whose length ranged from 103 to 5445 bp. In this dataset we identified 92 SSR (simple sequence repeats) motifs in 89 contigs. Forty-six of these had flanking regions suitable for primer design. We tested PCR amplification, reproducibility, and the level of polymorphism of 46 primer pairs for Orthotrichum speciosum using 40 individuals from two populations. As a result, the designed primers revealed 35 polymorphic loci with more than two alleles detected. This method is cost- and time-effective in comparison with traditional approaches involving cloning and sequencing. Full article

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Open AccessArticle

Carrier Injection and Transport in Blue Phosphorescent Organic Light-Emitting Device with Oxadiazole Host

by Tien-Lung Chiu and Pei-Yu Lee

Int. J. Mol. Sci. 2012, 13(6), 7575-7585; https://doi.org/10.3390/ijms13067575 - 19 Jun 2012

Cited by 37 | Viewed by 8291

Abstract

In this paper, we investigate the carrier injection and transport characteristics in iridium(III)bis[4,6-(di-fluorophenyl)-pyridinato-N,C2']picolinate (FIrpic) doped phosphorescent organic light-emitting devices (OLEDs) with oxadiazole (OXD) as the bipolar host material of the emitting layer (EML). When doping Firpic inside the OXD, the driving voltage of [...] Read more.

In this paper, we investigate the carrier injection and transport characteristics in iridium(III)bis[4,6-(di-fluorophenyl)-pyridinato-N,C2']picolinate (FIrpic) doped phosphorescent organic light-emitting devices (OLEDs) with oxadiazole (OXD) as the bipolar host material of the emitting layer (EML). When doping Firpic inside the OXD, the driving voltage of OLEDs greatly decreases because FIrpic dopants facilitate electron injection and electron transport from the electron-transporting layer (ETL) into the EML. With increasing dopant concentration, the recombination zone shifts toward the anode side, analyzed with electroluminescence (EL) spectra. Besides, EL redshifts were also observed with increasing driving voltage, which means the electron mobility is more sensitive to the electric field than the hole mobility. To further investigate carrier injection and transport characteristics, FIrpic was intentionally undoped at different positions inside the EML. When FIrpic was undoped close to the ETL, driving voltage increased significantly which proves the dopant-assisted-electron-injection characteristic in this OLED. When the undoped layer is near the electron blocking layer, the driving voltage is only slightly increased, but the current efficiency is greatly reduced because the main recombination zone was undoped. However, non-negligible FIrpic emission is still observed which means the recombination zone penetrates inside the EML due to certain hole-transporting characteristics of the OXD. Full article

(This article belongs to the Section Physical Chemistry, Theoretical and Computational Chemistry)

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Open AccessArticle

DNA Polymorphisms of the Lipoprotein Lipase Gene and Their Association with Coronary Artery Disease in the Saudi Population

by Abdulaziz A. Al-Jafari, Mohamed S. Daoud, Abdulelah F. Mobeirek and Mohammad S. Al Anazi

Int. J. Mol. Sci. 2012, 13(6), 7559-7574; https://doi.org/10.3390/ijms13067559 - 18 Jun 2012

Cited by 12 | Viewed by 6489

Abstract

Coronary heart disease (CHD) is a major health problem and a major cause of death in most countries. Evidence has been presented that gene polymorphisms (HindIII, PvuII and Ser447Ter) of lipoprotein lipase (LPL) are risk factors of coronary artery disease [...] Read more.

Coronary heart disease (CHD) is a major health problem and a major cause of death in most countries. Evidence has been presented that gene polymorphisms (HindIII, PvuII and Ser447Ter) of lipoprotein lipase (LPL) are risk factors of coronary artery disease (CAD). Aim: Our objective of the present investigation was to determine whether 3 LPL polymorphisms (LPL-HindIII, LPL-PvuII and LPL-Ser447Ter) can be considered as independent risk factors for CAD in the Saudi population. Methods: We recruited 120 CAD subjects, confirmed angiographically with identical ethnic backgrounds and 65 control subjects. Polymerase chain reaction-restriction fragment length polymorphisms (RFLP) technique was used to detect the polymorphisms of the LPL gene. Results and conclusion: For the HindIII genotype, within the CAD group, the frequencies of the H⁺H⁺ were found in 50.8%, whereas 44.2% carried the H⁻H⁺genotype, and 5% carried the H⁻H⁻ genotype. Within the control group, the H⁺H⁺ genotype was found in 44.6%, whereas 35.4% carried the H⁻H⁺genotype, 20% carried the H⁻H⁻genotype. The odds ratio (OR) of HindIII genotype H⁺H⁺ vs. H⁻H⁻ genotype at 95% Confidence Interval (CI) were 4.6 (1.57–13.2) and p < 0.005, hence showing no significant association with CAD. For the PvuII genotype, within the CAD group the frequencies of the P⁺P⁺ found in 41.7% whereas 43.3.2% carried the P⁻P⁺ genotype, and 15% carried the P⁻P⁻ genotype. Within the control group the P⁺P⁺ was found in 38.5%, 43.0% carried the P⁻P⁺genotype, and 18.5% carried the P⁻P⁻ genotype. The OR of PvuII genotype P⁺P⁺vs. P⁻P⁻genotypes (95% CI) is 1.33 and p = 0.52; hence, it was also insignificant to show association with the disease. For the Ser447Ter genotype, within the CAD group, the frequencies of the C/C found in 83.3%, whereas 16.7% carried the C/G genotype. Within the control group, the C/C was found in 87.7% and 12.3% carried the C/G genotype. We did not get any GG genotypes in control as well as patients for this gene. It can be concluded that C allele of gene masks the presence of G allele in the Saudi population. The OR of CG + GG vs. CC (95% CI) is 1.43 from 0.59 to 3.44 which is insignificant. Hence this gene also has no significant association with CAD in the Saudi population. Full article

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Open AccessArticle

Effect of ZnO on the Physical Properties and Optical Band Gap of Soda Lime Silicate Glass

by Mohd Hafiz Mohd Zaid, Khamirul Amin Matori, Sidek Hj. Abdul Aziz, Azmi Zakaria and Mohd Sabri Mohd Ghazali

Int. J. Mol. Sci. 2012, 13(6), 7550-7558; https://doi.org/10.3390/ijms13067550 - 18 Jun 2012

Cited by 107 | Viewed by 10007

Abstract

This manuscript reports on the physical properties and optical band gap of five samples of soda lime silicate (SLS) glass combined with zinc oxide (ZnO) that were prepared by a melting and quenching process. To understand the role of ZnO in this glass [...] Read more.

This manuscript reports on the physical properties and optical band gap of five samples of soda lime silicate (SLS) glass combined with zinc oxide (ZnO) that were prepared by a melting and quenching process. To understand the role of ZnO in this glass structure, the density, molar volume and optical band gaps were investigated. The density and absorption spectra in the Ultra-Violet-Visible (UV-Visible) region were recorded at room temperature. The results show that the densities of the glass samples increased as the ZnO weight percentage increased. The molar volume of the glasses shows the same trend as the density: the molar volume increased as the ZnO content increased. The optical band gaps were calculated from the absorption edge, and it was found that the optical band gap decreased from 3.20 to 2.32 eV as the ZnO concentration increased. Full article

(This article belongs to the Section Materials Science)

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Open AccessArticle

Prediction of a New Ligand-Binding Site for Type 2 Motif based on the Crystal Structure of ALG-2 by Dry and Wet Approaches

by Takeshi Takahashi, Hironori Suzuki, Tatsutoshi Inuzuka, Hideki Shibata and Masatoshi Maki

Int. J. Mol. Sci. 2012, 13(6), 7532-7549; https://doi.org/10.3390/ijms13067532 - 18 Jun 2012

Cited by 9 | Viewed by 7397

Abstract

ALG-2 is a penta-EF-hand Ca²⁺-binding protein and interacts with a variety of intracellular proteins. Two types of ALG-2-binding motifs have been determined: type 1, PXYPXnYP (X, variable; n = 4), in ALIX and PLSCR3; type [...] Read more.

ALG-2 is a penta-EF-hand Ca²⁺-binding protein and interacts with a variety of intracellular proteins. Two types of ALG-2-binding motifs have been determined: type 1, PXYPXnYP (X, variable; n = 4), in ALIX and PLSCR3; type 2, PXPGF, in Sec31A and PLSCR3. The previously solved X-ray crystal structure of the complex between ALG-2 and an ALIX peptide containing type 1 motif showed that the peptide binds to Pocket 1 and Pocket 2. Co-crystallization of ALG-2 and type 2 motif-containing peptides has not been successful. To gain insights into the molecular basis of type 2 motif recognition, we searched for a new hydrophobic cavity by computational algorithms using MetaPocket 2.0 based on 3D structures of ALG-2. The predicted hydrophobic pocket designated Pocket 3 fits with N-acetyl-ProAlaProGlyPhe-amide, a virtual penta-peptide derived from one of the two types of ALG-2-binding sites in PLSCR3 (type 2 motif), using the molecular docking software AutoDock Vina. We investigated effects of amino acid substitutions of the predicted binding sites on binding abilities by pulldown assays using glutathione-S-transferase -fused ALG-2 of wild-type and mutant proteins and lysates of cells expressing green fluorescent protein -fused PLSCR3 of wild-type and mutants. Substitution of either L52 with Ala or F148 with Ser of ALG-2 caused loss of binding abilities to PLSCR3 lacking type 1 motif but retained those to PLSCR3 lacking type 2 motif, strongly supporting the hypothesis that Pocket 3 is the binding site for type 2 motif. Full article

(This article belongs to the Section Molecular Recognition)

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Open AccessArticle

Mechanism of Cellular Oxidation Stress Induced by Asymmetric Dimethylarginine

by Srinidi Mohan and Ho-Leung Fung

Int. J. Mol. Sci. 2012, 13(6), 7521-7531; https://doi.org/10.3390/ijms13067521 - 18 Jun 2012

Cited by 18 | Viewed by 6173

Abstract

The mechanism by which asymmetric dimethylarginine (ADMA) induces vascular oxidative stress is not well understood. In this study, we utilized human umbilical vein endothelial cells (HUVEC) to examine the roles of ADMA cellular transport and the uncoupling of endothelial nitric oxide synthase (eNOS) [...] Read more.

The mechanism by which asymmetric dimethylarginine (ADMA) induces vascular oxidative stress is not well understood. In this study, we utilized human umbilical vein endothelial cells (HUVEC) to examine the roles of ADMA cellular transport and the uncoupling of endothelial nitric oxide synthase (eNOS) in contributing to this phenomenon. Dihydroethidium (DHE) fluorescence was used as an index of oxidative stress. Whole cells and their isolated membrane fractions exhibited measureable increased DHE fluorescence at ADMA concentrations greater than 10 µM. ADMA-induced DHE fluorescence was inhibited by co-incubation with L-lysine, tetrahydrobiopterin (BH₄), or L-nitroarginine methyl ester (L-NAME). Oxidative stress induced in these cells by angiotensin II (Ang II) were unaffected by the same concentrations of L-lysine, L-NAME and BH₄. ADMA-induced reduction in cellular nitrite or nitrite/nitrate production was reversed in the presence of increasing concentrations of BH₄. These results suggest that ADMA-induced DHE fluorescence involves the participation of both the cationic transport system in the cellular membrane and eNOS instead of the Ang II-NADPH oxidase pathway. Full article

(This article belongs to the Special Issue ADMA and Nitrergic System)

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Open AccessArticle

The Effect of Toll-Like Receptor 4 on Macrophage Cytokines During Endotoxin Induced Uveitis

by Shuo Yang, Hong Lu, Jing Wang, Xin Qi, Xuhui Liu and Xiaolong Zhang

Int. J. Mol. Sci. 2012, 13(6), 7508-7520; https://doi.org/10.3390/ijms13067508 - 18 Jun 2012

Cited by 16 | Viewed by 5980

Abstract

Toll-like receptor 4 (TLR4) signal activation of macrophages can lead to endotoxin-induced uveitis (EIU). Previously, our research group has demonstrated a higher expression of TLR4 in vivo during EIU than normal. In this study, we analyzed levels of peritoneal macrophage cytokines from C3H/HeN [...] Read more.

Toll-like receptor 4 (TLR4) signal activation of macrophages can lead to endotoxin-induced uveitis (EIU). Previously, our research group has demonstrated a higher expression of TLR4 in vivo during EIU than normal. In this study, we analyzed levels of peritoneal macrophage cytokines from C3H/HeN mice with LPS stimulation in vitro to elucidate the effect of TLR4 on cytokines during EIU. Full article

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Open AccessArticle

Simulated Gastrointestinal pH Condition Improves Antioxidant Properties of Wheat and Rice Flours

by Kim Wei Chan, Nicholas M. H. Khong, Shahid Iqbal and Maznah Ismail

Int. J. Mol. Sci. 2012, 13(6), 7496-7507; https://doi.org/10.3390/ijms13067496 - 18 Jun 2012

Cited by 20 | Viewed by 6342

Abstract

The present study was conducted to evaluate the antioxidant properties of wheat and rice flours under simulated gastrointestinal pH condition. After subjecting the wheat and rice flour slurries to simulated gastrointestinal pH condition, both slurries were centrifuged to obtain the crude phenolic extracts [...] Read more.

The present study was conducted to evaluate the antioxidant properties of wheat and rice flours under simulated gastrointestinal pH condition. After subjecting the wheat and rice flour slurries to simulated gastrointestinal pH condition, both slurries were centrifuged to obtain the crude phenolic extracts for further analyses. Extraction yield, total contents of phenolic and flavonoids were determined as such (untreated) and under simulated gastrointestinal pH condition (treated). 1,1-diphenyl-2-picrylhydrazyl radical (DPPH^•) scavenging activity, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radical cation (ABTS^•+) scavenging activity, ferric reducing antioxidant power (FRAP), beta-carotene bleaching (BCB) and iron chelating activity assays were employed for the determination of antioxidant activity of the tested samples. In almost all of the assays performed, significant improvements in antioxidant properties (p < 0.05) were observed in both flours after treatment, suggesting that wheat and rice flours contain considerably heavy amounts of bound phenolics, and that their antioxidant properties might be improved under gastrointestinal digestive conditions. Full article

(This article belongs to the Section Biochemistry)

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Open AccessArticle

Optimization of Glutamine Peptide Production from Soybean Meal and Analysis of Molecular Weight Distribution of Hydrolysates

by Yanli Xie, Xinhong Liang, Min Wei, Wenhong Zhao, Baoshan He, Qiyu Lu, Quangong Huo and Chengye Ma

Int. J. Mol. Sci. 2012, 13(6), 7483-7495; https://doi.org/10.3390/ijms13067483 - 18 Jun 2012

Cited by 16 | Viewed by 7462

Abstract

The process parameters of enzymatic hydrolysis and molecular weight distribution of glutamine (Gln) peptides from soybean meal were investigated. The Protamex^® hydrolysis pH of 6.10, temperature of 56.78 °C, enzyme to substrate ratio (E/S) of 1.90 and hydrolysis time of 10.72 h [...] Read more.

The process parameters of enzymatic hydrolysis and molecular weight distribution of glutamine (Gln) peptides from soybean meal were investigated. The Protamex^® hydrolysis pH of 6.10, temperature of 56.78 °C, enzyme to substrate ratio (E/S) of 1.90 and hydrolysis time of 10.72 h were found to be the optimal conditions by response surface methodology (RSM) for a maximal degree of hydrolysis (DH) value of 16.63% and Gln peptides content at 5.95 mmol/L. The soybean meal was hydrolyzed by a combination of Protamex^® and trypsinase so that DH and Gln peptides would reach 22.02% and 6.05 mmol/mL, respectively. The results of size exclusion chromatography indicated that the relative proportion of the molecular weight < 1000 Da fraction increased with DH values from 6.76%, 11.13%, 17.89% to 22.02%, most notably the 132–500 Da fractions of hydrolysates were 42.14%, 46.57%, 58.44% and 69.65%. High DH values did not lead to high Gln peptides content of the hydrolysate but to the low molecular weight Gln peptides. Full article

(This article belongs to the Special Issue Enzyme Optimization and Immobilization)

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Open AccessArticle

Vibrational Stark Effect of the Electric-Field Reporter 4-Mercaptobenzonitrile as a Tool for Investigating Electrostatics at Electrode/SAM/Solution Interfaces

by Gal Schkolnik, Johannes Salewski, Diego Millo, Ingo Zebger, Stefan Franzen and Peter Hildebrandt

Int. J. Mol. Sci. 2012, 13(6), 7466-7482; https://doi.org/10.3390/ijms13067466 - 18 Jun 2012

Cited by 60 | Viewed by 10709

Abstract

4-mercaptobenzonitrile (MBN) in self-assembled monolayers (SAMs) on Au and Ag electrodes was studied by surface enhanced infrared absorption and Raman spectroscopy, to correlate the nitrile stretching frequency with the local electric field exploiting the vibrational Stark effect (VSE). Using MBN SAMs in different [...] Read more.

4-mercaptobenzonitrile (MBN) in self-assembled monolayers (SAMs) on Au and Ag electrodes was studied by surface enhanced infrared absorption and Raman spectroscopy, to correlate the nitrile stretching frequency with the local electric field exploiting the vibrational Stark effect (VSE). Using MBN SAMs in different metal/SAM interfaces, we sorted out the main factors controlling the nitrile stretching frequency, which comprise, in addition to external electric fields, the metal-MBN bond, the surface potential, and hydrogen bond interactions. On the basis of the linear relationships between the nitrile stretching and the electrode potential, an electrostatic description of the interfacial potential distribution is presented that allows for determining the electric field strengths on the SAM surface, as well as the effective potential of zero-charge of the SAM-coated metal. Comparing this latter quantity with calculated values derived from literature data, we note a very good agreement for Au/MBN but distinct deviations for Ag/MBN which may reflect either the approximations and simplifications of the model or the uncertainty in reported structural parameters for Ag/MBN. The present electrostatic model consistently explains the electric field strengths for MBN SAMs on Ag and Au as well as for thiophenol and mercaptohexanoic acid SAMs with MBN incorporated as a VSE reporter. Full article

(This article belongs to the Special Issue Self-Assembled Soft Matter Nanostructures at Interfaces)

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636 KiB

Open AccessArticle

Identification of Intensity Ratio Break Points from Photon Arrival Trajectories in Ratiometric Single Molecule Spectroscopy

by Dieter Bingemann and Rachel M. Allen

Int. J. Mol. Sci. 2012, 13(6), 7445-7465; https://doi.org/10.3390/ijms13067445 - 18 Jun 2012

Cited by 2 | Viewed by 6983

Abstract

We describe a statistical method to analyze dual-channel photon arrival trajectories from single molecule spectroscopy model-free to identify break points in the intensity ratio. Photons are binned with a short bin size to calculate the logarithm of the intensity ratio for each bin. [...] Read more.

We describe a statistical method to analyze dual-channel photon arrival trajectories from single molecule spectroscopy model-free to identify break points in the intensity ratio. Photons are binned with a short bin size to calculate the logarithm of the intensity ratio for each bin. Stochastic photon counting noise leads to a near-normal distribution of this logarithm and the standard student t-test is used to find statistically significant changes in this quantity. In stochastic simulations we determine the significance threshold for the t-test’s p-value at a given level of confidence.We test the method’s sensitivity and accuracy indicating that the analysis reliably locates break points with significant changes in the intensity ratio with little or no error in realistic trajectories with large numbers of small change points, while still identifying a large fraction of the frequent break points with small intensity changes. Based on these results we present an approach to estimate confidence intervals for the identified break point locations and recommend a bin size to choose for the analysis. The method proves powerful and reliable in the analysis of simulated and actual data of single molecule reorientation in a glassy matrix. Full article

(This article belongs to the Special Issue Advances in Single Molecule Spectroscopy)

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433 KiB

Open AccessReview

Dietary Supplementations as Neuroprotective Therapies: Focus on NT-020 Diet Benefits in a Rat Model of Stroke

by Yuji Kaneko, Lourdes Cortes, Cyndy Sanberg, Sandra Acosta, Paula C. Bickford and Cesar V. Borlongan

Int. J. Mol. Sci. 2012, 13(6), 7424-7444; https://doi.org/10.3390/ijms13067424 - 15 Jun 2012

Cited by 12 | Viewed by 7863

Abstract

Stroke remains the number one cause of disability in the adult population. Despite scientific progress in our understanding of stroke pathology, only one treatment (tissue plasminogen activator or tPA) is able to afford benefits but to less than 3% of ischemic stroke patients. [...] Read more.

Stroke remains the number one cause of disability in the adult population. Despite scientific progress in our understanding of stroke pathology, only one treatment (tissue plasminogen activator or tPA) is able to afford benefits but to less than 3% of ischemic stroke patients. The development of experimental dietary supplement therapeutics designed to stimulate endogenous mechanisms that confer neuroprotection is likely to open new avenues for exploring stroke therapies. The present review article evaluates the recent literature supporting the benefits of dietary supplementation for the therapy of ischemic stroke. This article focuses on discussing the medical benefits of NT-020 as an adjunct agent for stroke therapy. Based on our preliminary data, a pre-stroke treatment with dietary supplementation promotes neuroprotection by decreasing inflammation and enhancing neurogenesis. However, we recognize that a pre-stroke treatment holds weak clinical relevance. Thus, the main goal of this article is to provide information about recent data that support the assumption of natural compounds as neuroprotective and to evaluate the therapeutic effects of a dietary supplement called NT-020 as in a stroke model. We focus on a systematic assessment of practical treatment parameters so that NT-020 and other dietary supplementations can be developed as an adjunct agent for the prevention or treatment of chronic diseases. We offer rationale for determining the optimal dosage, therapeutic window, and mechanism of action of NT-020 as a dietary supplement to produce neuroprotection when administered immediately after stroke onset. We highlight our long-standing principle in championing both translational and basic science approaches in an effort to fully reveal the therapeutic potential of NT-020 as dietary supplementation in the treatment of stroke. We envision dietary supplementation as an adjunct therapy for stroke at acute, subacute, and even chronic periods. Full article

(This article belongs to the Special Issue Neuroprotective Strategies 2012)

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Open AccessReview

Hierarchical Assembly of Multifunctional Oxide-based Composite Nanostructures for Energy and Environmental Applications

by Pu-Xian Gao, Paresh Shimpi, Haiyong Gao, Caihong Liu, Yanbing Guo, Wenjie Cai, Kuo-Ting Liao, Gregory Wrobel, Zhonghua Zhang, Zheng Ren and Hui-Jan Lin

Int. J. Mol. Sci. 2012, 13(6), 7393-7423; https://doi.org/10.3390/ijms13067393 - 15 Jun 2012

Cited by 32 | Viewed by 10628

Abstract

Composite nanoarchitectures represent a class of nanostructured entities that integrates various dissimilar nanoscale building blocks including nanoparticles, nanowires, and nanofilms toward realizing multifunctional characteristics. A broad array of composite nanoarchitectures can be designed and fabricated, involving generic materials such as metal, ceramics, and [...] Read more.

Composite nanoarchitectures represent a class of nanostructured entities that integrates various dissimilar nanoscale building blocks including nanoparticles, nanowires, and nanofilms toward realizing multifunctional characteristics. A broad array of composite nanoarchitectures can be designed and fabricated, involving generic materials such as metal, ceramics, and polymers in nanoscale form. In this review, we will highlight the latest progress on composite nanostructures in our research group, particularly on various metal oxides including binary semiconductors, ABO₃-type perovskites, A₂BO₄ spinels and quaternary dielectric hydroxyl metal oxides (AB(OH)₆) with diverse application potential. Through a generic template strategy in conjunction with various synthetic approaches—such as hydrothermal decomposition, colloidal deposition, physical sputtering, thermal decomposition and thermal oxidation, semiconductor oxide alloy nanowires, metal oxide/perovskite (spinel) composite nanowires, stannate based nanocompostes, as well as semiconductor heterojunction—arrays and networks have been self-assembled in large scale and are being developed as promising classes of composite nanoarchitectures, which may open a new array of advanced nanotechnologies in solid state lighting, solar absorption, photocatalysis and battery, auto-emission control, and chemical sensing. Full article

(This article belongs to the Section Materials Science)

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162 KiB

Open AccessArticle

Aroma Volatile Compounds from Two Fresh Pineapple Varieties in China

by Liang-Yong Zheng, Guang-Ming Sun, Yu-Ge Liu, Ling-Ling Lv, Wen-Xiu Yang, Wei-Feng Zhao and Chang-Bin Wei

Int. J. Mol. Sci. 2012, 13(6), 7383-7392; https://doi.org/10.3390/ijms13067383 - 14 Jun 2012

Cited by 70 | Viewed by 9491

Abstract

Volatile compounds from two pineapples varieties (Tainong No.4 and No.6) were isolated by headspace solid phase microextraction (HS-SPME) and identified and quantified by gas chromatography-mass spectrometry (GC/MS). In the Tainong No. 4 and No. 6 pineapples, a total of 11 and 28 volatile [...] Read more.

Volatile compounds from two pineapples varieties (Tainong No.4 and No.6) were isolated by headspace solid phase microextraction (HS-SPME) and identified and quantified by gas chromatography-mass spectrometry (GC/MS). In the Tainong No. 4 and No. 6 pineapples, a total of 11 and 28 volatile compounds were identified according to their retention time on capillary columns and their mass spectra, and quantified with total concentrations of 1080.44 µg·kg⁻¹ and 380.66 µg·kg⁻¹ in the Tainong No.4 and No. 6 pineapples, respectively. The odor active values (OAVs) of volatile compounds from pineapples were also calculated. According to the OAVs, four compounds were defined as the characteristic aroma compounds for the Tainong No. 4 pineapple, including furaneol, 3-(methylthio)propanoic acid methyl ester, 3-(methylthio)propanoic acid ethyl ester and δ-octalactone. The OAVs of five compounds including ethyl-2-methylbutyrate, methyl-2-methylbutyrate, 3-(methylthio)propanoic acid ethyl ester, ethyl hexanoate and decanal were considered to be the characteristic aroma compounds for the Tainong No. 6 pineapple. Full article

(This article belongs to the Section Biochemistry)

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Int. J. Mol. Sci., Volume 13, Issue 6 (June 2012) – 83 articles , Pages 6534-7871

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