Search Results (1,873)

Eragrostis nindensis is a resurrection grass capable of surviving near-complete desiccation. We compared non-senescent leaf tissue (NST) and senescent leaf tissue (ST) to investigate the cellular and molecular basis of desiccation tolerance and senescence. NST recovered fully after drying, while ST failed to regain viability. Integrated transcriptomic (using RNA-Seq), lipidomic (using LC-MS), and ultrastructural (Transmission Electron Microscopical) analyses revealed that NST maintain RNA processing, protein folding, and translational activity during desiccation. Lipidomic data and ultrastructure showed preferential accumulation of polyunsaturated triacylglycerols (TAGs) and lipid droplets in NST, supporting membrane protection and energy buffering. In contrast, ST showed cellular collapse, reduced oleosin protein accumulation, and signatures of senescence. These findings highlight the importance of post-transcriptional and post-translational regulation, as well as lipid metabolism, in preserving cellular integrity during desiccation in this species. Full article

Nosemosis is a disease caused by microsporidia, which are strictly intracellular pathogens, currently considered to be most closely related to fungi. These microscopic parasites infect a variety of hosts, significantly affecting honeybees (Apis mellifera). Nosemosis is one of the most serious diseases of bees and is caused primarily by two species: Nosema apis and Nosema ceranae. This infection adversely affects the digestive tract of the bees, causes a reduction in their vitality, and can lead to the death of entire colonies. The diagnosis of nosemosis has undergone extensive development. Traditionally, the identification of microsporidia was performed by examination of bee digestive tract (macerated) by light microscopy. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are expensive methods that require skilled personnel and were used only when high resolution was necessary. Modern methods, such as polymerase chain reaction (PCR), allow detection of infection at species and genotype levels, thereby increasing the accuracy of diagnosis. Despite advances in molecular techniques, research into nosemosis still faces challenges. This review focuses on a comparison of different diagnostic techniques and their pitfalls that can be integrated into strategies to combat nosemosis and protect the health of honeybee colonies. Full article

The fabrication of highly loaded and uniformly dispersed metal oxide nanoparticles (NPs) is much desired but still remains a great challenge. Herein, the NiO NPs exclusively confined in mesoporous silica SBA-15 were obtained by using nickel nitrate hydrate as a precursor through a facile solvent-free preparation method, which comprised manual grinding of Ni(NO₃)₂·6H₂O with SBA-15 and subsequent air calcination. Characterization results from X-ray diffraction (XRD) and transmission electron microscope (TEM) revealed that aggregation-free NiO nanoparticles with sizes of 3–5 nm were obtained at loading as high as 20 wt.% (weight%). Further increasing the NiO loading to 30 wt.% led to partial agglomeration of discrete nanoparticles to rod-like particles, while no external particles were observed. By comparing the sample derived from nickel acetate with exclusively external NiO particles, it was established that the pore confinement provided NiO nanoparticles with high thermal stability. Lastly, the catalytic performance of the prepared sample was evaluated in the model reaction of ammonia decomposition to CO_x-free H₂, and the stable NH₃ conversion of 93.7% was achieved at the weight hourly space velocity (WHSV) value of 30,000 mL·g⁻¹·h⁻¹ and at high temperature of 650 °C for 60 h, demonstrating the great potential of the solvent-free method in preparing thermally stable and robust supported catalysts. Full article

In this study, the exhaust particulates of a diesel engine burning methanol/F-T diesel blends were collected. The nanostructure and oxidation reactivity of the particulates were explored using the Brunauer–Emmett–Teller (BET) method, high-resolution transmission electron microscope (HRTEM), and thermogravimetric analysis (TGA), and the relationship between them was assessed via the partial least squares (PLS) and variable importance in the projection (PLS-VIP). The results showed that particulates from methanol/F-T diesel combustion were aggregates composed of several primary particles, and the distribution range of particulate half pore width ($R$) was 8~76 nm. As the methanol mixture ratio increased, the mean $R$ of particulates decreased, and the particulates′ total pore volume ($V_p$), specific surface area ($S_{BET}$), and the fractal dimension ($D_f$) increased. Compared with F-T diesel, methanol/F-T diesel blends particulates showed more disordered structure with a smaller diameter ($d_p$) of primary particles, a shorter fringe length ($L_a$), a wider separation distance ($d$), and a larger tortuosity ($T_f$). With increasing the methanol mixture ratio, it was also found that the amount of soluble organic fraction (SOF) of particulates increased, while oxidation characteristic temperature and the apparent activation energy ($E_a$) reduced. The correlation coefficients of $E_a$ with $T_f$ and $D_f$ were 0.99 and 0.98, respectively, by the linear fitting, illustrating that they showed the strongest linear relationship with the reactivity among the discussed nanostructure parameters. The VIP values of $D_f$, $T_f$, $V_p$, and d, with $E_a$ obtained by the PLS and PLS-VIP, were greater than 1, indicating that they were the chief factors influencing particulate reactivity. Full article

Thermoelectric (TE) materials represent a critical frontier in sustainable energy conversion technologies, providing direct thermal-to-electrical energy conversion with solid-state reliability. The optimizations of TE performance demand a nuanced comprehension of structure–property relationships across diverse length scales. This review summarizes established and emerging spectroscopic and microscopic techniques used to characterize inorganic and polymer TE materials, specifically poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS). For inorganic TE, ultraviolet–visible (UV–Vis) spectroscopy, energy-dispersive X-ray (EDX) spectroscopy, and X-ray photoelectron spectroscopy (XPS) are widely applied for electronic structure characterization. For phase analysis of inorganic TE materials, Raman spectroscopy (RS), electron energy loss spectroscopy (EELS), and nuclear magnetic resonance (NMR) spectroscopy are utilized. For analyzing the surface morphology and crystalline structure, chemical scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) are commonly used. For polymer TE materials, ultraviolet−visible–near-infrared (UV−Vis−NIR) spectroscopy and ultraviolet photoelectron spectroscopy (UPS) are generally employed for determining electronic structure. For functional group analysis of polymer TE, attenuated total reflectance–Fourier-transform infrared (ATR−FTIR) spectroscopy and RS are broadly utilized. XPS is used for elemental composition analysis of polymer TE. For the surface morphology of polymer TE, atomic force microscopic (AFM) and SEM are applied. Grazing incidence wide-angle X-ray scattering (GIWAXS) and XRD are employed for analyzing the crystalline structures of polymer TE materials. These techniques elucidate electronic, structural, morphological, and chemical properties, aiding in optimizing TE properties like conductivity, thermal stability, and mechanical strength. This review also suggests future research directions, including in situ methods and machine learning-assisted multi-dimensional spectroscopy to enhance TE performance for applications in electronic devices, energy storage, and solar cells. Full article

With the acceleration of industrialization, the impact of the toxic metalloid arsenic (As) and metal lead (Pb) on aquatic ecosystems has garnered widespread concern. However, the specific toxic effects of how these two metals jointly impact aquatic organisms are not yet fully understood. This study aims to investigate the toxic effects of As and Pb individually and in combination of the mixture on the growth of Chlamydomonas reinhardtii (C. reinhardtii) in a lab setup using the Concentration Addition (CA) model and the Independent Action (IA) model to predict the toxic effects at different concentrations. The results indicated that As and Pb had significant inhibitory effects on the growth of algae, and the toxicity of As was greater than that of Pb (As EC50 = 374.87 μg/L, Pb EC50 = 19,988.75 μg/L), measured by Spectrophotometer. As the metal concentrations increased, both metals demonstrated classic sigmoidal concentration-effect curves. Furthermore, we discovered that in mixtures of As and Pb at varying concentration ratios, the combined toxic effect shifted from additive to synergistic with increasing As concentration, exhibiting a pronounced concentration ratio dependency. Utilizing nonlinear least squares regression, we successfully constructed concentration-response models for both As and Pb, employing Observation-based Confidence Intervals (OCIs) to reflect the uncertainty of the data. By comparing experimental data with model predictions, the EC50 was used as an index to compare the toxicity magnitude of As/Pb mixtures. The toxicity of As and Pb mixtures gradually increases with the increase in their concentration ratios. Scanning and transmission electron microscopic observations revealed that the combination of 200 μg/L As and 2000 μg/L Pb resulted in the greatest synergistic toxic effect, with severe breakage and indentation to C. reinhardtii cells. This study not only provided new insights into the environmental behavior and ecological risks of As and Pb but also held significant implications for effective water pollution management strategies by offering a validated model-based framework for predicting mixture toxicity across different concentration regimes. Full article

To address the technical challenges in bisphenol A (BPA) pollution control, this research introduced a novel synthetic approach combining co-precipitation with subsequent thermal treatment to engineer layered double hydroxides (LDHs) with a spinel-structured CoMn-LDO catalyst. Systematic material characterizations such as a scanning electron microscope (SEM), an X-ray diffractometer (XRD), a transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS) were employed to analyze the structural and chemical properties of the synthesized CoMn-LDO calcined at 500 °C. The catalytic performance was evaluated under optimized conditions (35 °C, pH 7.0, 2.0 mM PMS, 0.3 g/L catalyst), and mechanistic studies were conducted to identify the dominant reactive oxygen species. The CoMn-LDO exhibited exceptional peroxymonosulfate (PMS) activation performance, achieving 96.75% BPA degradation within 90 min and 58.22% TOC removal. The synergistic redox cycling between Co²⁺/Co³⁺ and Mn³⁺/Mn⁴⁺ promoted the generation of ·OH (72.3% contribution) and SO₄^·−. The catalyst demonstrated superior stability, maintaining 89% degradation efficiency after five cycles. These results provide theoretical and practical insights for developing high-efficiency persulfate-activating catalysts. Full article

The reforming of methane using carbon dioxide, also known as dry reforming (DRM), is an environmentally benign method that utilizes greenhouse gases (methane and carbon dioxide) to produce a mixture of carbon monoxide and hydrogen. This study evaluated the catalytic performance of nickel-based catalysts supported over SBA-16 (5Ni/SBA-16) promoted with 0.5 to 3 wt% of gadolinium (Gd). The characterization results of the catalysts, including textural properties, crystallite size, reducibility, morphology, acidity/basicity, and carbon deposition, facilitated the understanding of the insights of catalytic activity and stability performance of these catalysts. The incorporation of a suitable amount (1 wt%) of Gd promoter had a significant impact on the activity, resulting in the highest CH₄ and CO₂ conversions 69 and 78%, respectively. The higher specific surface area, higher reducibility, better dispersion, and smaller active metal particle size were the major factors contributing to the relatively better performance of 5Ni+1Gd/SBA-16. Morphological analysis using a transmission electron microscope showed the formation of carbon nanotubes over unpromoted 5Ni/SBA-16, in contrast to no significant carbon formation over 5Ni+1Gd/SBA-16. The process optimization results indicated that the experimental results were in agreement with the theoretically optimized findings. Full article

Nanocrystals of Eu-doped GaN powders are produced via pyrolysis of a viscous compound made from europium and gallium nitrates. Furthermore, carbohydrazide is used as a fuel and toluene as a solvent; subsequently, a crucial nitridation process is carried out at 1000 °C for one hour. A slight shift of 0.04 degrees toward larger angles was observed for the X-ray diffraction patterns in the Eu-doped GaN powders regarding the undoped GaN powders, while Raman scattering also displayed a slight shift of 10.03 cm⁻¹ toward lower frequencies regarding the undoped GaN powders for the vibration mode, E₂(H), in both cases indicating the incorporation of europium atoms into the GaN crystal lattice. A scanning electron microscope micrograph demonstrated a surface morphology for the Eu-doped GaN with a shape similar to elongated platelets with a size of 3.77 µm in length. Energy-dispersive spectroscopy and X-ray photoelectron spectroscopy studies demonstrated the europium elemental contribution in the GaN. The X-ray photoelectron spectroscopy spectrum for gallium demonstrated the binding energies for Ga 2P_3/2, Ga 2P_1/2, and Eu 3d_5/2, which could indicate the incorporation of europium into the GaN and the bonding between gallium and europium atoms. The transmission electron microscope micrograph showed the presence of nanocrystals with an average size of 9.03 nm in length. The photoluminescence spectrum showed the main Eu³⁺ transition at 2.02 eV (611.69 nm) for europium emission energy, corresponding to the ⁵D₀ ⟶ ⁷F₂ transition of the f shell, which is known as a laser transition. Full article

The microstructures and mechanical and corrosion properties of Mg-12Gd-2Zn-xNd-0.4Zr (x = 0, 0.5, and 1.0 wt.%) alloys after hot-extrusion have been studied by scanning electron microscope (SEM), transmission electron microscope (TEM), electron back scattered diffraction (EBSD), X-ray diffractometer (XRD), electronic universal testing machine, atomic force microscope (AFM), immersion, and electrochemical tests. The results show that all the alloys consist of an α-Mg matrix, β phase, and stacking faults (SFs). Obvious texture (<$\overline{1}2\overline{1}0$> parallel to the extrusion direction and the direction close to <0001>) can be found due to the introduction of the Nd element. The yield strength (YS) of the alloys with Nd additions in different testing conditions is higher than that without Nd addition. The addition of 0.5 wt.% Nd achieves the highest tensile YS at room temperature (262 MPa) and 180 °C (251 MPa), along with compression YS (246 MPa), attributable to grain refinement, stacking faults, texture, and solute atom strengthening. Moreover, the compression YS to tensile YS ratio of the as-extruded alloy increases from 0.87 to 0.98, indicating a significant improvement of tension–compression YS asymmetry. The Nd addition also plays a great role in the enhanced corrosion resistance of the alloys. Specifically, the corrosion potential of the different phases in the alloys shows the following order: β phase > SFs > α-Mg matrix. The alloy with 0.5 wt.% Nd addition exhibits the best corrosion resistance owing to its lower corrosion potential difference between the β phase and α-Mg matrix. Full article

Aluminum nitride (AlN) powder, a cornerstone material for advanced ceramics. This study examines the low-temperature formation of AlN crystals as well as their phase transformation by employing amorphous aluminum oxalate (AAO) as a novel precursor for carbothermal reduction, contrasting it with conventional aluminum hydroxide (Al(OH)₃). Through characterization using X-ray diffraction (XRD), scanning electron microscopy (SEM), High-Resolution Transmission Electron Microscope (HRTEM), ²⁷Al Magic-Angle Spinning Nuclear Magnetic Resonance (²⁷Al-MAS-NMR) energy-dispersive spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FTIR), we unraveled the phase evolution pathways and the formation of AlN. Key findings reveal striking differences between the two precursors. When Al(OH)₃ was used, no AlN phase was detected at 1350 °C, and even at 1500 °C, the AlN obtained with significant residual alumina impurities. In contrast, the AAO precursor demonstrated exceptional efficiency: nano-sized α-Al₂O₃ formed at 1050 °C, followed by the emergence of AlN phases at 1200 °C, ultimately gaining the pure AlN at 1500 °C. The phase transformation sequence—Al(OH)₃ → γ-Al₂O₃ (950 °C) → (α-Al₂O₃ + δ-Al₂O₃) (1050 °C) → (AlN + α-Al₂O₃) (1200 °C~ 1350 °C) → AlN (≥1500 °C)—highlights the pivotal role of nano-sized α-Al₂O₃ in enabling low-temperature nano AlN synthesis. By leveraging the unique properties of AAO, we offer a transformative strategy for synthesizing nano-sized AlN powders, with profound implications for the ceramics industry. Full article

Monitoring dopamine (DA) has attracted increasing attention due to alterations in DA levels associated with brain disorders. In addition, the urinary DA concentration plays a significant role in the sympathoadrenal system. A decrease in DA can impair reward-seeking behavior and cognitive flexibility. Therefore, accurate and precise DA detection is necessary. In this study, a poly(3-aminobenzylamine)/functionalized multi-walled carbon nanotube (PABA/f-CNT) composite thin film was fabricated by electrochemical synthesis, or electropolymerization, of 3-aminobenzylamine (3-ABA) monomer and f-CNTs through cyclic voltammetry (CV) on a fluorine-doped tin oxide (FTO)-coated glass substrate, which also served as a working electrode for label-free DA detection in artificial urine. The formation of the film was confirmed by the obtained cyclic voltammogram, electrochemical impedance spectroscopy (EIS) plots, and scanning electron microscope (SEM) and transmission electron microscope (TEM) images. The chemical components of the films were analyzed using attenuated total reflection–Fourier transform infrared (ATR–FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). For label-free DA detection, various concentrations (50–1000 nM) of DA were determined in buffer solution through differential pulse voltammetry (DPV). The fabricated PABA/f-CNT film presented two linear ranges of 50–400 nM (R² = 0.9915) and 500–1000 nM (R² = 0.9443), with sensitivities of 1.97 and 0.95 µA·cm⁻²·µM⁻¹, respectively. The limit of detection (LOD) and the limit of quantity (LOQ) were 119.54 nM and 398.48 nM, respectively. In addition, the PABA/f-CNT film provided excellent selectivity against common interferents (ascorbic acid, uric acid, and glucose) with high stability, reproducibility, and repeatability. For potential future medical applications, DA detection was further performed in artificial urine, yielding a high percentage of recovery. Full article

GH4706 Ni-based superalloy is widely used for aero-engine turbine disks operating below 700 °C, where high-temperature ductility is critical to avoid cracking during die forging and service. However, the microscopic mechanisms by which stabilization treatment regulates its high-temperature ductility remain insufficiently clarified. This study systematically investigated the tensile deformation behavior at a high temperature of 650 °C of the GH4706 Ni-based superalloy after stabilization treatment. Transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS) were employed to characterize microstructural evolution and elemental redistribution to clarify the microscopic mechanisms by which stabilization treatment enhanced the high-temperature ductility of the GH4706 alloy. The experimental results indicated that better high-temperature plasticity was obtained, although tensile strength decreased slightly after stabilization. This improvement was mainly attributed to the precipitation of the η phase (Ni₃Ti) and its synergistic interaction with the matrix, which effectively enhanced the plastic deformation capacity of the GH4706 alloy at elevated temperatures. Moreover, η phase precipitation and elemental segregation enhanced grain boundary stability, thus inhibiting crack initiation and delaying necking. SIMS analysis revealed that boron, phosphorus, and sulfur showed significant segregation along grain boundaries during 650 °C tensile testing following stabilization—an effect considered crucial to the observed ductility enhancement. TEM observations further indicated that the interaction between η phase precipitation and the nucleation and evolution of stacking faults during deformation together reduced local stress concentrations and promoted uniform plastic deformation. Full article

Nitrosamines, including N-nitroso diethylamine (NDEA) have emerged as pharmaceutical impurities and carcinogenic environmental contaminants of grave public health safety concerns. This study reports on the preparation and first use of cysteine–gold nanoparticles (CysAuNPs) for colorimetric detection of NDEA in human serum albumin (HSA) under physiological conditions. Molecular docking (MD) and molecular dynamic simulation (MDS) were performed to probe the interaction between NDEA and serum albumin. UV–visible absorption and fluorescence spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM) imaging were used to characterize the synthesized CysAuNPs. These CysAuNPs show a UV–visible absorbance wavelength maxima (λ_max) at 377 nm and emission λ_max at 623 nm. Results from DLS measurement revealed the CysAuNPs’ uniform size distribution and high polydispersity index of 0.8. Microscopic imaging using TEM showed that CysAuNPs have spherical to nanoplate-like morphology. The addition of NDEA to HSA in the presence of CysAuNPs resulted in a remarkable increase in the absorbance of human serum albumin. The interaction of NDEA–CysAuNPs–HSA is plausibly facilitated by hydrogen bonding, sulfur linkages, or by Cys–NDEA-induced electrostatic and van der Waal interactions. These are due to the disruption of the disulfide bond linkage in Cys–Cys upon the addition of NDEA, causing the unfolding of the serum albumin and the dispersion of CysAuNPs. The combined use of molecular dynamic simulation and colorimetric experiment provided complementary data that allows robust analysis of NDEA in serum samples. In addition, the low cost of the UV–visible spectrophotometer and the easy preparation and optical sensitivity of CysAuNPs sensors are desirable, allowing the low detection limit of the CysAuNPs sensors, which are capable of detecting as little as 0.35 µM NDEA in serum albumin samples, making the protocol an attractive sensor for rapid detection of nitrosamines in biological samples. Full article

Sarcocystis is a genus of heteroxenous, globally distributed coccidian parasites. Limited research has been conducted on the natural infection of Sarcocystis in rodents in the Middle East. In this study, the Libyan jird (Meriones libycus) was identified as the natural intermediate host of the new species Sarcocystis meriones, based on morphological and molecular data. Microscopic sarcocysts were detected in the thigh muscles of 8.5% (4/47) of Libyan jirds captured from a semi-desert area in Amghara, Eastern Kuwait. Under the light microscope, sarcocysts were filamentous with blunt ends and thin walls, measuring 1550 × 89 µm. Transmission electron microscopy analysis showed the densely packed protrusions measure 1.2 × 0.5 µm and resemble thuja or a cylinder and having lateral microvilli, while the ground substance layer was 0.5–0.6 µm thick and type 22-like. Based on four genetic loci (18S rRNA, 28S rRNA, ITS1, and cox1), S. meriones was genetically most similar to S. myodes and S. ratti, infecting voles and mice of the genus Apodemus and black rats (Rattus rattus), respectively. Phylogenetic results suggest predatory mammals as potential definitive hosts of S. meriones. Further studies are needed to reveal host specificity, geographical distribution, and the impact of the parasite on the host’s health of the newly described Sarcocystis species. Full article