Search Results (255)

Purpose: This study aimed to refine the criteria for EndoART implantation regarding posterior corneal irregularity; to improve the selection of candidates for this synthetic alternative to endothelial keratoplasty. Methods: This study analyzed the impact of posterior corneal surface elevation differences; anterior chamber depth (ACD); and preoperative corneal pachymetry on the success of EndoART implant adhesion. Patients undergoing EndoART implantation at the Medical University of Vienna were assessed using OCT to measure corneal irregularities. Postoperative outcomes, including re-bubbling rates; implant adhesion; and visual acuity changes, were monitored. Results: EndoART successfully adhered in eyes with moderate posterior irregularities (elevation differences up to 204 µm). Severe irregularities (elevation differences > 200 µm) resulted in implant detachment. No significant correlation was found between corneal pachymetry or ACD and adhesion failure. Glaucoma devices and prior penetrating keratoplasty did not significantly affect adhesion. Some cases required re-bubbling, and patients reported pain reduction and moderate improvements in visual acuity. Conclusions: This study found that EndoART implantation can be successful despite posterior corneal irregularity. EndoART represents a viable solution for patients with poor biological graft survival prognosis, including those with glaucoma or prior surgeries, expanding its potential use and addressing the global donor cornea shortage. Full article

In order to explore the optimal vibration parameters for the selective harvesting of coffee fruits, a high-velocity dynamic photography monitoring system was developed to analyze the vibration-assisted harvesting process. This system identified the optimal vibration position on coffee branches and facilitated theoretical energy transfer analysis, obtaining a mathematical formula for calculating the total kinetic energy of coffee branches. A single-factor experiment was conducted with the vibration position as the experimental factor and the total kinetic energy of coffee branches as the response variable. The results showed that the total kinetic energy of the branches was the highest at Vibration Position 2 (the position between the third and the fourth Y-shaped bud tips on the branch). Therefore, Vibration Position 2 was determined as the optimal vibration position. Further analysis established a mathematical model linking coffee cherry motion parameters to theoretical detachment force. A factorial experiment was conducted with vibration frequency and amplitude as test factors, using detachment rates of green, semi-ripe, and ripe cherries as indicators. The results showed that at 55 Hz and 10.10 mm amplitude, the detachment rate of ripe cherries was highest (83.33%), while green and semi-ripe cherries detached at 16.67% and 33.33%, respectively. A field validation experiment, with Vibration Position 2, 55 Hz frequency, 10.10 mm amplitude, and 1 s vibration duration, yielded actual detachment rates of 15.86%, 35.17%, and 89.50% for green, semi-ripe, and ripe cherries, respectively. The error margins compared with the theoretical values were all below 10%. These results confirm the feasibility of optimizing vibration harvesting parameters through high-velocity photography dynamic analysis. Full article

In recent years, polycrystalline diamond compact (PDC) drill bits have seen significant advancements. They have replaced over 90% of the workload traditionally handled by roller cone bits and have become the predominant choice in energy drilling due to their superior efficiency and durability. However, PDC drill bits are susceptible to adhesion of rock cuttings during drilling in muddy formations, leading to mud accumulation on the bit surface. This phenomenon can cause drill bit failure and may contribute to downhole complications, including tool failure and borehole instability. The adhesion issue between PDC drill bits and mud rock cuttings underground is primarily influenced by the normal adhesion force between the drill bit surface and the mud rock cuttings. Therefore, biological non-smooth surface technology is applied to the prevention and control of drill bit balling. It is an optimal selection of biomimetic non-smooth surface structures with reduced adhesion and detachment properties. A non-smooth surface model for the PDC drill bit body is established through the analysis of the morphological characteristics of natural biological non-smooth surfaces. An experimental platform is designed and manufactured to evaluate the adhesion performance of non-smooth surface specimens. Indoor experiments are conducted to test the normal adhesion force of non-smooth surface specimens under varying morphologies, sizes, and contact times with clay. Finally, the anti-adhesion performance of the non-smooth surface unit structures is then analyzed. The normal adhesion force with a contact time of 12 h is as follows: 340 Pa of big square raised, 250 Pa of middle square raised, 190 Pa of small square raised, 315 Pa of big circular groove, 280 Pa of middle circular groove, 200 Pa of small circular groove, 225 Pa of big dot pit, 205 Pa of middle dot pit, and 130 Pa of small dot pit. Compared with the normal adhesion force of 550 Pa for smooth surface specimens with a contact time of 12 h, the anti-adhesion properties of the three non-smooth surface unit structure specimens designed in this paper were verified. We analyzed the anti-adhesion performance of non-smooth surface unit structures. At the critical contact time when the adhesion force tends to stabilize, the adhesion forces of different specimens are as follows: 330 Pa of big square raised, 237.5 Pa of middle square raised, 175 Pa of small square raised, 290 Pa of big circular groove, 250 Pa of middle circular groove, 160 Pa of small circular groove, 210 Pa of big dot pit, 185 Pa of middle dot pit, and 115 Pa of small dot pit. The results indicate that the anti-adhesion effect of small dot pit structures is the most effective, while the anti-adhesion effect of large square convex structures is the least effective. As the size of the unit structure decreases, it becomes more similar to the surface size of the organism. Additionally, a shorter contact time with clay leads to a better anti-adhesion effect. These findings provide new insights and research directions for the effective prevention and control of mud wrapping on PDC drill bits. Full article

The rapid regulatory mechanism of light-induced state transitions (STs) in oxygenic photosynthesis is particularly appealing for membrane-based applications. This interest stems from the unique ability of the thylakoid membrane protein cytochrome b₆f (cytb₆f) to increase or decrease its hydrophobic thickness (d_P) in parallel with the reduction or oxidation of the PQ pool induced by changes in light quality. This property appears to be the long-sought biophysical driver behind the reorganizations of membrane proteins during STs. This study decisively advances the hydrophobic mismatch (HMM) model for cytb₆f-driven STs by thoroughly analyzing thirteen X-ray crystal and eight cryo-electron microscopy cytb₆f structures. It uncovers the lipid nanoenvironments that cytb₆f, with different hydrophobic thicknesses, selectively attracts. Under optimal, stationary conditions for photosynthesis in low light, when there is hydrophobic matching between the hydrophobic thicknesses of cytb₆f d_P and that of the bulk thylakoid lipid phase d_L, d_P = d_L, cytb₆f predominantly binds to anionic lipids—several phosphatidylglycerol (PG) molecules and one sulfoquinovosyldiacylglycerol (SQDG) molecule. Upon the induction of the transition to State 2, when d_P increases and induces a positive HMM (d_P > d_L), the neutral, non-bilayer-forming lipid monogalactosyldiacylglycerol (MGDG) replaces some of the bound PGs. Upon the induction of the transition to State 1, when d_P decreases and induces a negative HMM (d_P < d_L), PGs and SQDG detach from their binding sites, and two neutral, bilayer-forming lipids such as digalactosyldiacylglycerol (DGDG) occupy two sites. Additionally, this research uncovers two lipid-mediated signaling pathways from Chla to the center of flexibility, the Phe/Tyr124^fg-loop-suIV residue—one of which involves β-carotene. This study identifies two novel types of lipid raft-like nanodomains that are devoid of typical components, such as sphingomyelin and cholesterol. These findings firmly validate the HMM model and underscore the STs as the first recognized functional process that fully utilizes the unique and evolutionarily conserved composition of just four thylakoid lipid classes. This research contributes to our understanding of membrane dynamics in general and STs in particular. It introduces a novel and simple approach for reversible protein reorganization driven purely by biophysical mechanisms, with promising implications for various membrane-based applications. Full article

Parasitic diseases constitute a significant challenge to global public health, with Strongyloides stercoralis ranking among the most prevalent and clinically significant parasites. The limitations of current nematocidal therapies highlight an urgent need for novel treatment strategies. In this study, the nematocidal activity of chalepensin and graveoline, two compounds isolated from Ruta chalepensis, was evaluated against larval and adult stages of Strongyloides venezuelensis (model for S. stercoralis). The in vitro efficacy of these compounds was assessed on third-stage infective larvae (L3) and adult parthenogenetic females at various time points, while cytotoxicity was determined using Vero cells to calculate selectivity indices (SI). Both compounds showed good antiparasitic activity, but chalepensin exhibited superior nematocidal activity compared to graveoline, with an LC₅₀ of 3.9 µg/mL and an SI of 990 for L3, and an LC₅₀ of 16.8 µg/mL and an SI of 200 for adult females at 72 h. Morphological analysis via scanning electron microscopy in adult females revealed that graveoline induced mostly cuticle detachment, while chalepensin caused protuberances across the parasite body. These findings suggest that both compounds possess promising antiparasitic potential, with chalepensin emerging as a particularly potent candidate for further exploration. Full article

This work investigates the effect of the addition of tungsten carbide (WC) particles as reinforcements to Ni (Inconel 625) versus Co (Stellite 6) alloys during deposition by laser cladding to form wear-resistant metal matrix composite (MMC) coatings. While the related literature often associates the presence of WC with the enhanced wear performance of MMC coatings, this work shows that such an effect is not universal as it may critically depend on the metallic matrix employed. Thus, to demonstrate whether the reinforcement and matrix act synergically in such a scenario or not, MMC coatings formed by Inconel 625 and Stellite 6, both with WC content ranging from 10% to 40%, were deposited under the same laser cladding setup on AISI 304 stainless steel substrates, being WC-free samples produced together for comparison basis. As expected, the hardness levels increased with more WC presence in both matrices, but the wear resistance was specifically evaluated by means of the metal wheel abrasion test (ASTM B611). The results revealed that the use of WC as a reinforcement indeed affects the matrix materials differently; for Stellite 6, the wear resistance increased with up to 20% of WC (in contrast to the hardness indication), whereas for Inconel 625, the wear resistance progressively decreased with more WC content. It was observed via scanning electron microscopy (SEM) that the WC particles within the Inconel 625 alloy tended to intensive cracking, being in this way more prone to detach from the matrix and hence representing a weakening factor for the effectiveness of the coatings produced. Thus, it is concluded that the addition of WC particles, as potential reinforcements for MMC coatings, is not always effective (synergic with the matrix) in providing wear resistance, hence, opposing the prevailing consensus. This outcome and its reasons will certainly help with insights into proper design of MMC coatings, starting with the importance of matrix material selection. Full article

Ice accumulation on heating, ventilation, air conditioning, and refrigeration (HVACR) structures presents significant operational challenges. These challenges include reduced efficiency, increased energy consumption, and potential damage to equipment. Traditional de-icing methods, such as chemical treatments, mechanical scraping, or heating-based techniques, are often labor-intensive, costly, and environmentally harmful. This study uniquely investigates ultrasonic de-icing as an energy-efficient alternative for HVACR applications, focusing on the specific structural geometries found in these systems. A comprehensive numerical simulation framework was developed using finite element analysis to explore ultrasonic wave propagation across four distinct HVACR structures. Key parameters such as ultrasonic frequency, power levels, and the number and placement of actuators were examined for their impact on ice detachment efficiency. Results from simulations on a plate structure reveal that ultrasonic excitation can propagate effectively across large areas (at least 150 × 150 mm), enhancing the de-icing coverage. Lower frequency (e.g., 30 to 45 kHz) excitation results in greater displacement, improving de-icing performance, while increased actuator numbers with the same total power input also enhance effectiveness. Two actuators seem sufficient for the de-icing of a 300 × 300 mm plate. For tube-and-fin structures, specific high-power ultrasonic frequencies selectively excite the fin plates, demonstrating efficient ice removal when actuated on the tube. However, optimal performance requires careful design of actuator placement and vibration modes to accommodate the irregular shapes of these structures. Full article

Retinal detachment (RD) is a vision-threatening ocular emergency that necessitates rapid diagnosis and intervention. This review examines the evolving role of optical coherence tomography (OCT) in RD by synthesizing the literature on preoperative biomarkers and advanced image modalities that inform diagnosis, prognosis, and surgical planning. We evaluated studies employing spectral-domain OCT, swept-source OCT, OCT angiography, adaptive optics OCT, and en face OCT to assess photoreceptor integrity, retinal detachment height, intraretinal cystic cavities, outer retinal corrugations and undulation, and macular involvement. The incorporation of OCT assessment into clinical practice may facilitate more precise surgical timing, technique selection, and postoperative monitoring. Further research is needed to standardize imaging protocols and validate specific prognostic biomarkers for optimal surgical outcomes. Key aspects include uniform imaging protocols, validating OCT-derived biomarkers such as ellipsoid zone integrity, and correlating OCT metrics with functional outcomes. Full article

The electrochemical carbon dioxide reduction reaction (CO₂RR) represents a promising approach for achieving CO₂ resource utilization. Carbon-based materials featuring single-atom transition metal-nitrogen coordination (M-N_x) have attracted considerable research attention due to their ability to maximize catalytic efficiency while minimizing metal atom usage. However, conventional synthesis methods often encounter challenges with metal particle agglomeration. In this study, we developed a Ni-doped polyvinylidene fluoride (PVDF) fiber membrane via electrospinning, subsequently transformed into a nitrogen-doped three-dimensional self-supporting single-atom Ni catalyst (Ni-N-CF) through controlled carbonization. PVDF was partially defluorinated and crosslinked, and the single carbon chain is changed into a reticulated structure, which ensured that the structure did not collapse during carbonization and effectively solved the problem of runaway M-Nx composite in the high-temperature pyrolysis process. Grounded in X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS), nitrogen coordinates with nickel atoms to form a Ni-N structure, which keeps nickel in a low oxidation state, thereby facilitating CO₂RR. When applied to CO₂RR, the Ni-N-CF catalyst demonstrated exceptional CO selectivity with a Faradaic efficiency (FE) of 92%. The unique self-supporting architecture effectively addressed traditional electrode instability issues caused by catalyst detachment. These results indicate that by tuning the local coordination structure of atomically dispersed Ni, the original inert reaction sites can be activated into efficient catalytic centers. This work can provide a new strategy for designing high-performance single-atom catalysts and structurally stable electrodes. Full article

Background: Rhegmatogenous retinal detachment (RRD) is an ophthalmological emergency that can lead to vision loss if left untreated. Pars plana vitrectomy (PPV) is the preferred procedure for most complex RRD cases with a high success rate. However, certain parameters related to the patient, disease history, or ocular presentation may influence surgical outcomes. Methods: A systematic review of studies from 2010 to 2023 was conducted using PubMed/Medline (National Library of Medicine, Bethesda, MD, USA) and Scopus (Elsevier, Netherlands). The main objective of this review is to present the most significant data published in the scientific literature over the last 10 years, focusing on the latest implications of prognostic factors affecting the success of PPV in RRD. The search included terms such as “prognostic factors”, “visual outcome”, “functional outcome”, and “rhegmatogenous retinal detachment”. The database search returned 3489 studies. The included studies had to involve participants with RRD treated mainly by PPV, a minimum of 10 participants, and at least a 6-month follow-up period. Studies were excluded if they involved patients with previous PPV treatment or trauma. After reviewing their abstracts, titles, and applying the exclusion criteria, 19 articles were selected. Because it is an ample and interesting topic, many authors explored the connection between prognostic factors involved in the management of RRD and the final visual and functional outcomes. Methodological quality was assessed using PRISMA guidelines. Results: various factors have been studied, ranging from classic ophthalmological parameters, such as refractive error, axial length, lens status, visual acuity, duration of symptoms, description of the RRD, and retinal tears, to more complex findings on optical coherence tomography. Conclusions: The factors that significantly influenced postoperative prognosis in RRD included preoperative best-corrected visual acuity (BCVA), duration of symptoms, macular status (on/off), extent of retinal detachment, presence of macular hole, and proliferative vitreoretinopathy (PVR). Disruption of the ellipsoid zone (EZ), presence of epiretinal membrane (ERM), and lack of external limiting membrane (ELM) integrity were associated with poorer outcomes following RRD surgery. Full article

Point-of-care (POC) antigen detection plays a crucial role in curbing the spread of viruses. Paper-based fluorescence aptasensors are expected to offer a low-cost tool to meet the needs of decentralized POC diagnosis. Herein, we report on a fluorescent paper-based sensing system for detecting the SARS-CoV-2 spike protein. The sensing system was constructed by loading multi-layer Nb₂C MXene nano-quenchers and carbon-dot-labeled aptamer (G-CDs@Apt) probes onto a mixed cellulose ester (MCE) paper substrate. On the Nb₂C MXene/G-CDs@Apt sensing paper, abundant G-CDs@Apt probes were attached to the multilayer MXene nano-quenchers and kept in a fluorescence-off state, while recognition of the target detached the G-CDs@Apt probes formed the nano--quenchers, resulting in fluorescence recovery of the sensing paper. The developed paper-based sensor performed well in the one-step detection of the SARS-CoV-2 S1 protein with a detection limit of 0.067 ng/mL (0.335 pg/test). The assay exhibited good selectivity and anti-interference in the detection of the SARS-CoV-2 S1 protein in artificial saliva. Moreover, the paper-based aptasensor was successfully used to detect the SARS-CoV-2 S1 protein in actual environmental samples with recoveries of 90.87–100.55% and relative standard deviations of 1.52–3.41%. The proposed technology provides a cost-effective alternative to traditional antibody test strips for a wide range of POC diagnostic applications. Full article

Objective: This study aimed to evaluate the outcomes and predictive factors of I-125 radioactive plaque therapy for recurrent and refractory retinoblastoma (Rb) cases that failed primary systemic chemotherapy and focal therapies. Methods: A retrospective study of 20 eyes with intraocular Rb treated with I-125 radioactive plaque therapy (Apex dose 45 Gy) from 2013 to 2023 was conducted. Data on tumor characteristics, treatments, and outcomes were collected over a follow-up period of at least one year. Results: There were 11 (55%) males and 8 (40%) patients who had bilateral disease. All 20 treated eyes (100%) showed initial tumor regression, while long-term tumor control and eye salvage were achieved in 14 eyes (70%). Six eyes (30%) experienced uncontrollable tumor recurrence after a mean of 6 months (range: 3–12 months) after plaque therapy. Recurrence included main tumor activity in six eyes and additional resistant vitreous seeds in two of them. Poor predictive factors for eye salvage included Group D at diagnosis (p = 0.044), active vitreous seeds at the time of plaque therapy ((p = 0.045), tumor thickness >5.0 mm (p = 0.045), and tumor base dimension >12 mm (p = 0.023). Post-plaque complications included cataracts in seven eyes (35%), tumor hemorrhage in six eyes (30%), retinal detachment in four eyes (20%), radiation retinopathy in three eyes (15%), and neovascular glaucoma in one eye (5%). Five (83%) of those with tumor hemorrhage had plaque surgery performed within less than 6 months of the last cycle of systemic chemotherapy. At a mean follow-up of 36 months (range: 12–96 months), five eyes (25%) were enucleated, and high-risk pathological features were identified in three eyes, including post-laminar optic nerve infiltration (one eye) and massive choroidal invasion (two eyes). All patients were alive and free of metastasis except one patient (5%) whose parents refused enucleation and came back with extra-scleral extension and bone marrow metastasis and eventually passed away. Conclusions: I-125 radioactive plaque therapy is a valuable salvage treatment for recurrent and refractory retinoblastoma, achieving tumor control and eye salvage in 70% of cases with an acceptable safety profile. However, the observed recurrence rate (30%) at an apex dose of 45 Gy suggests a need for dose optimization and individualized treatment strategies. Identifying high-risk features, such as Group D disease, active vitreous seeds, and larger tumors, is crucial for patient selection and outcome prediction. Future research should explore alternative dosing strategies, combination therapies, and improved predictive models to enhance long-term tumor control while minimizing complications. Full article

One of the issues the modern hip implants face is that one side of the implant may detach due to stretching during its use. This leads to implant transverse compression and separation from the bone. This issue can be solved by using complex implants having one of the sides made of auxetic meta-biomaterials with negative Poisson’s ratio. On the contrary, the cross-section of such materials being stretched will increase, which results in bone growth stimulation and minimum possibility of implant detachment. The aim of this paper is to design and fabricate titanium alloy auxetic meta-biomaterials based on 3D unit cells with three types of topologies. The works involved computer simulation to determine the expected properties of the samples. The samples were fabricated by the selective laser melting method and their properties were determined. Auxetic meta-biomaterials with Poisson’s ratio values of −0.09 and −0.003 and elastic modulus values typical for a human trabecular bone were fabricated in the course of the works. Full article

One of the methods used to improve the durability of blueberry fruits is the application of nutrients through foliar feeding with calcium, which can improve the post-harvest mechanical parameters. This study proposed an optimal selection of calcium spray parameters, which enables a rational minimisation of the negative impact of agrochemicals in the environment. The qualitative evaluation of blueberry fruit showed lime spraying induces a significant effect on the increase in fruit size, especially at a pressure of 0.2 MPa and with AIXR nozzles compared to the control group. To assess the mechanical properties, a modern method of identifying the actual loads and maximum surface pressures generated by the picker during harvesting is presented. Compression and fruit rupture tests were also used to determine the pressure values and forces that are considered safe from the perspective of harvest quality. The comparative analysis of destructive compression and detachment tests confirmed that fruit firmness (Fp) was approximately 80% higher than the detachment force (Fpf), with peak pressures more than twice as high, suggesting that handpicking poses minimal risk of mechanical damage. The implementation of optimal spraying techniques combined with the correct assessment of the mechanical properties of fruits is important in agricultural practice, where it is crucial to obtain high-quality blueberries after harvest. Full article

Mycoplasma bovis is one of the most important pathogens in animal husbandry, and the current infection and morbidity rates are increasing year by year, causing great losses to the farming industry and seriously affecting animal welfare. In this study, we took tracheal tissues from calves infected with M. bovis to make pathological tissue sections for observation, and selected tracheal tissues for transcriptome sequencing to screen differentially expressed genes based on the threshold |log2FoldChange| > 1 and Padjust < 0.05 and functional enrichment, to explore in depth the potential mechanisms of bovine tracheal damage caused by bovine tracheitis. Experiments were conducted to observe the changes in tracheal tissues after M. bovis infection through pathological sections of the trachea of M. bovis-infected calves. From the transcriptome sequencing results, we mined the main differential genes and important metabolic pathways of M. bovis causing damage to the trachea of calves. It was found that the cricoid cartilage tissue of the trachea was congested and hemorrhagic after M. bovis infection in calves, and the pathological sections showed localized necrosis of epithelial cells, disorganization, high inflammatory cell infiltration in the interepithelial and lamina propria, and some epithelial cell detachment. Transcriptome sequencing identified 4199 DEGs, including 1378 up-regulated genes and 2821 down-regulated genes. KEGG enrichment analysis indicated that the differential genes were enriched to 59 significantly differing signaling pathways, and a number of important metabolic pathways related to tracheitis induced by M. bovis-infected calves were unearthed. The major ones included IL-17, the Toll-like receptor, JAK/STAT, the PI3K-Akt signaling pathway, etc. In this study, we found that M. bovis infection of calves caused inflammatory damage to the trachea, and transcriptome sequencing results also showed significant differences in the expression of key genes such as IL-6 inflammatory factor, CASP8, and APOA1. Full article