Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.066
Filtrar
1.
Stat Med ; 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38747472

RESUMO

The U.S. Food and Drug Administration (FDA) has launched Project Optimus to shift dose selection from the maximum tolerated dose (MTD) to the dose that produces the optimal risk-benefit tradeoff. One approach highlighted in the FDA's guidance involves conducting a randomized phase II trial following the completion of a phase I trial, where multiple doses (typically including the MTD and one or two doses lower than the MTD) are compared to identify the optimal dose that maximizes the benefit-risk tradeoff. This article focuses on the design of such a multiple-dose randomized trial, specifically the determination of the sample size. We generalized the standard definitions of type I error and power to accommodate the unique characteristics of dose optimization and derived a decision rule along with an algorithm to determine the optimal sample size. The resulting design is referred to as MERIT (Multiple-dosE RandomIzed Trial design for dose optimization based on toxicity and efficacy). Simulation studies demonstrate that MERIT has desirable operating characteristics, and a sample size between 20 and 40 per dosage arm often offers reasonable power and type I errors to ensure patient safety and benefit. To facilitate the implementation of the MERIT design, we provide software, available at https://www.trialdesign.org.

2.
Water Res ; 258: 121759, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38754299

RESUMO

Waste activated sludge serves an important reservoir for antibiotics within wastewater treatment plants, and understanding the occurrence and evolution of antibiotics during sludge treatment is crucial to mitigate the potential risks of subsequent resource utilization of sludge. This study explores the degradation and transformation mechanisms of three typical antibiotics, oxytetracycline (OTC), ofloxacin (OFL), and azithromycin (AZI) during sludge hydrothermal treatment (HT), and investigates the influence of biopolymers transformation on the fate of these antibiotics. The findings indicate that HT induces a shift of antibiotics from solid-phase adsorption to liquid-phase dissolution in the initial temperature range of 25-90 °C, underscoring this phase's critical role in preparing antibiotics for subsequent degradation phases. Proteins (PN) and humic acids emerge as crucial for antibiotic binding, facilitating their redistribution within sludge. Specifically, the binding capacity sequence of biopolymers to antibiotics is as follows: OFL>OTC>AZI, highlighting that OFL-biopolymers display stronger electrostatic attraction, more available adsorption sites, and more stable binding strength. Furthermore, antibiotic degradation mainly occurs above 90 °C, with AZI being the most temperature-sensitive, degrading 92.97% at 180 °C, followed by OTC (91.26%) and OFL (52.51%). Concurrently, the degradation products of biopolymers compete for active sites to form novel amino acid-antibiotic conjugates, which inhibits the further degradation of antibiotics. These findings illuminate the effects of biopolymers evolution on intricate dynamics of antibiotics fate in sludge HT and are helpful to optimize the sludge HT process for effective antibiotics abatement.

3.
J Lipids ; 2024: 5324127, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38757060

RESUMO

Background: Diabetic retinopathy (DR) is a diabetic microvascular complication and a leading cause of vision loss. However, there is a lack of effective strategies to reduce the risk of DR currently. The present study is aimed at assessing the causal effect of lipid-regulating targets on DR risk using a two-sample Mendelian randomization (MR) study. Method: Genetic variants within or near drug target genes, including eight lipid-regulating targets for LDL-C (HMGCR, PCSK9, and NPC1L1), HDL-C (CETP, SCARB1, and PPARG), and TG (PPARA and LPL), were selected as exposures. The exposure data were obtained from the IEU OpenGWAS project. The outcome dataset related to DR was obtained from the FinnGen research project. Inverse-variance-weighted MR (IVW-MR) was used to calculate the effect estimates by each target. Sensitivity analyses were performed to verify the robustness of the results. Results: There was suggestive evidence that PCSK9-mediated LDL-C levels were positively associated with DR, with OR (95% CI) of 1.34 (1.02-1.77). No significant association was found between the expression of HMGCR- and NPC1L1-mediated LDL-C levels; CETP-, SCARB1-, and PPARG-mediated HDL-C levels; PPARA- and LPL-mediated TG levels; and DR risk. Conclusions: This is the first study to reveal a genetically causal relationship between lipid-regulating drug targets and DR risk. PCSK9-mediated LDL-C levels maybe positively associated with DR risk at the genetic level. This study provides suggestive evidence that PCSK9 inhibition may reduce the risk of DR.

4.
Bioresour Technol ; 402: 130809, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38723729

RESUMO

Phosphorus is enriched in waste activated sludge (WAS) during wastewater treatment, and organic phosphorus (OP) is a potential slow-release P fertilizer. The chemical coagulants used in sludge dewatering leave numerous residues in WAS that affect sludge composting. In this study, the effects of polyaluminum chloride (PAC) and polyferric sulfate (PFS) on the bioconversion of dissolved OP (DOP) during sludge composting were investigated. The results revealed that PFS conditioning promoted the transformation and bioavailability of DOP, whereas PAC conditioning inhibited. Results indicated that PFS conditioning enhanced the transformation of OP molecules in the thermophilic phase. Through oxidation and dehydrogenation reactions, 1-hydroxy-pentane-3,4-diol-5-phosphate and D-ribofuranose 5-phosphate with high bioactivity were generated in the PFS-conditioned compost. Enzymatic hydrolysis experiments further verified that PFS conditioning enhanced the DOP bioavailability in the compost, whereas PAC conditioning inhibited it. The study has provided molecular insights into the effects of chemical conditioning on DOP conversion during sludge composting.

5.
J Clin Invest ; 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38713523

RESUMO

The smoothened (Smo) receptor facilitates hedgehog signaling between kidney fibroblasts and tubules during acute kidney injury (AKI). Tubule-derived hedgehog is protective in AKI, but the role of fibroblast-selective Smo is unclear. Here, we report that Smo-specific ablation in fibroblasts reduced tubular cell apoptosis and inflammation, enhanced perivascular mesenchymal cells activities, and preserved kidney function after AKI. Global proteomics of these kidneys identified extracellular matrix proteins, and nidogen-1 glycoprotein in particular, as key response markers to AKI. Intriguingly, Smo was bound to nidogen-1 in cells, suggesting that loss of Smo could impact nidogen-1 accessibility. Phosphoproteomics revealed that the 'AKI protector' Wnt signaling pathway was activated in these kidneys. Mechanistically, nidogen-1 interacted with integrin ß1 to induce Wnts in tubules to mitigate AKI. Altogether, our results support that fibroblast-selective Smo dictates AKI fate through cell-matrix interactions, including nidogen-1, and offers a robust resource and path to further dissect AKI pathogenesis.

6.
Lipids ; 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38741514

RESUMO

The elderly population is at a higher risk of cardiovascular complications, and dyslipidemia plays a significant role as a contributing factor. Chronic kidney disease (CKD) patients are prone to lipid abnormalities, further increasing the risk of cardiovascular complications. We aimed to investigate the lipid profile characteristics of the middle-aged and elderly population, particularly CKD patients. We conducted a cross-sectional study using baseline data from the Systolic Blood Pressure Intervention Trial (SPRINT). It was examined how lipid profiles are affected by age within the general population, and how BMI and lipid characteristics are affected by CKD subtype. Among 8746 participants, we observed a decreasing trend in LnTAG (natural logarithm of Triacylglycerol) and total Cholesterol (CHR) levels with increasing age, while high-density lipoprotein cholesterol (HDL-C) levels increased with age. In the CKD and non-CKD subgroups created through propensity score matching based on age, sex, and race, CKD individuals exhibited significantly higher average LnTAG levels across all age groups compared to the non-CKD group. Multivariable linear regression analysis, controlling for confounding variables, revealed a negative correlation between LnTAG and estimated glomerular filtration rate (eGFR) (r = -0.002, p < 0.001). HDL-C showed a positive correlation with eGFR (r = 0.057, p < 0.001). That is, in the middle-aged and elderly population, age demonstrated a negative correlation with total CHR and TAG levels, while exhibiting a positive correlation with HDL-C levels. CKD patients exhibited relatively higher TAG levels, which were positively associated with CKD progression.

7.
Nat Commun ; 15(1): 3759, 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38704384

RESUMO

Millimeter-scale soft continuum robots offer safety and adaptability in transluminal procedures due to their passive compliance, but this feature necessitates interactions with surrounding lumina, leading to potential medical risks and restricted mobility. Here, we introduce a millimeter-scale continuum robot, enabling apical extension while maintaining structural stability. Utilizing phase transition components, the robot executes cycles of tip-based elongation, steered accurately through programmable magnetic fields. Each motion cycle features a solid-like backbone for stability, and a liquid-like component for advancement, thereby enabling autonomous shaping without reliance on environmental interactions. Together with clinical imaging technologies, we demonstrate the capability of navigating through tortuous and fragile lumina to transport microsurgical tools. Once it reaches larger anatomical spaces such as stomach, it can morph into functional 3D structures that serve as surgical tools or sensing units, overcoming the constraints of initially narrow pathways. By leveraging this design paradigm, we anticipate enhanced safety, multi-functionality, and cooperative capabilities among millimeter-scale continuum robots, opening new avenues for transluminal robotic surgery.


Assuntos
Procedimentos Cirúrgicos Robóticos , Procedimentos Cirúrgicos Robóticos/instrumentação , Procedimentos Cirúrgicos Robóticos/métodos , Humanos , Desenho de Equipamento , Robótica/instrumentação , Robótica/métodos , Campos Magnéticos , Microcirurgia/instrumentação , Microcirurgia/métodos , Animais , Magnetismo
8.
ACS Nano ; 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38768086

RESUMO

Pericyte dysfunction severely undermines cerebrovascular integrity and exacerbates neurodegeneration in Alzheimer's disease (AD). However, pericyte-targeted therapy is a yet-untapped frontier for AD. Inspired by the elevation of vascular cell adhesion molecule-1 (VCAM-1) and reactive oxygen species (ROS) levels in pericyte lesions, we fabricated a multifunctional nanoprodrug by conjugating the hybrid peptide VLC, a fusion of the VCAM-1 high-affinity peptide VHS and the neuroprotective apolipoprotein mimetic peptide COG1410, to curcumin (Cur) through phenylboronic ester bond (VLC@Cur-NPs) to alleviate complex pericyte-related pathological changes. Importantly, VLC@Cur-NPs effectively homed to pericyte lesions via VLC and released their contents upon ROS stimulation to maximize their regulatory effects. Consequently, VLC@Cur-NPs markedly increased pericyte regeneration to form a positive feedback loop and thus improved neurovascular function and ultimately alleviated memory defects in APP/PS1 transgenic mice. We present a promising therapeutic strategy for AD that can precisely modulate pericytes and has the potential to treat other cerebrovascular diseases.

9.
ACS Omega ; 9(18): 20547-20556, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38737059

RESUMO

As a sustainable, nontoxic and environmentally friendly cyanide-free gold leaching agent, thiosulfate has been applied to some extent in the field of hydrometallurgy. However, the difficult recovery of gold ions in gold leaching solutions limits further application of thiosulfate gold leaching technology. This study demonstrated the feasibility of gold recovery by sodium dimethyldithiocarbamate (SDD) precipitation and recycling of ammonia and a lixiviant in solution. SDD achieved the purpose of recovering gold by forming granular precipitates with gold ions in solution. It can almost completely recover gold ions in 2.5-17.34 mg/L of gold leaching solution within 1 min at 25 °C, in which a gold recovery capacity of 7.99 kg/t is achieved. The leaching rate of gold ore did not change significantly after recycling the residual ammonia and thiosulfate in the leaching solution after gold recovery by SDD, and its leaching rate basically remained at 81%. The mechanism of SDD recovering Au was determined to involve the ligand exchange of SDD- and Au[(S2O3)2]3-. Moreover, the interaction mechanism between SDD and Au(I) was further validated by density functional theory calculations. Considering its low cost, simple technology, and environmental friendliness, the SDD precipitation process has the potential for large-scale application in gold recovery from thiosulfate gold leaching solutions.

10.
Plant Physiol Biochem ; 212: 108741, 2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38772167

RESUMO

Wurfbainia villosa and Wurfbainia longiligularis are the two primary plant sources of Fructus Amomi, a traditional Chinese medicine. Both plants are rich in volatile terpenoids, including monoterpenes and sesquiterpenes, which are the primary medicinal components of Fructus Amomi. The trans-isopentenyl diphosphate synthase (TIDS) gene family plays a key part in determining terpenoid diversity and accumulation. However, the TIDS gene family have not been identified in W. villosa and W. longiligularis. This study identified thirteen TIDS genes in W. villosa and eleven TIDS genes in W. longiligularis, which may have expanded through segmental replication events. Based on phylogenetic analysis and expression levels, eight candidate WvTIDSs and five WlTIDSs were selected for cloning. Functional characterization in vitro demonstrated that four homologous geranyl diphosphate synthases (GPPSs) (WvGPPS1, WvGPPS2, WlGPPS1, WlGPPS2) and two geranylgeranyl diphosphate synthases (GGPPSs) (WvGGPPS and WlGGPPS) were responsible for catalyzing the biosynthesis of geranyl diphosphate (GPP), whereas two farnesyl diphosphate synthases (FPPSs) (WvFPPS and WlFPPS) catalysed the biosynthesis of the farnesyl diphosphate (FPP). A comparison of six proteins with identified GPPS functions showed that WvGGPPS and WlGGPPS exhibited the highest activity levels. These findings indicate that homologous GPPS and GGPPS together promote the biosynthesis of GPP in W. villosa and W. longiligularis, thus providing sufficient precursors for the synthesis of monoterpenes and providing key genetic elements for Fructus Amomi variety improvement and molecular breeding.

11.
Chin J Traumatol ; 2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38744544

RESUMO

PURPOSE: The aim of the present study was to analyze the influence of muscle activation on lumbar injury under a specific +Gz load. METHODS: A hybrid finite element human body model with detailed lumbar anatomy and lumbar muscle activation capabilities was developed. Using the specific +Gz loading acceleration as input, the kinematic and biomechanical responses of the occupant's lower back were studied for both activated and deactivated states of the lumbar muscles. RESULTS: The results indicated that activating the major lumbar muscles enhanced the stability of the occupant's torso, which delayed the contact between the occupant's head and the headrest. Lumbar muscle activation led to higher strain and stress output in the lumbar spine under +Gz load, such as the maximum Von-Mises stress of the vertebrae and intervertebral discs increased by 177.9% and 161.8%, respectively, and the damage response index increased by 84.5%. CONCLUSION: In both simulations, the occupant's risk of lumbar injury does not exceed 10% probability. Therefore, the activation of muscles could provide good protection for maintaining the lumbar spine and reduce the effect of acceleration in vehicle travel direction.

12.
Signal Transduct Target Ther ; 9(1): 129, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38740763

RESUMO

The safety and efficacy of COVID-19 vaccines in the elderly, a high-risk group for severe COVID-19 infection, have not been fully understood. To clarify these issues, this prospective study followed up 157 elderly and 73 young participants for 16 months and compared the safety, immunogenicity, and efficacy of two doses of the inactivated vaccine BBIBP-CorV followed by a booster dose of the recombinant protein vaccine ZF2001. The results showed that this vaccination protocol was safe and tolerable in the elderly. After administering two doses of the BBIBP-CorV, the positivity rates and titers of neutralizing and anti-RBD antibodies in the elderly were significantly lower than those in the young individuals. After the ZF2001 booster dose, the antibody-positive rates in the elderly were comparable to those in the young; however, the antibody titers remained lower. Gender, age, and underlying diseases were independently associated with vaccine immunogenicity in elderly individuals. The pseudovirus neutralization assay showed that, compared with those after receiving two doses of BBIBP-CorV priming, some participants obtained immunological protection against BA.5 and BF.7 after receiving the ZF2001 booster. Breakthrough infection symptoms last longer in the infected elderly and pre-infection antibody titers were negatively associated with the severity of post-infection symptoms. The antibody levels in the elderly increased significantly after breakthrough infection but were still lower than those in the young. Our data suggest that multiple booster vaccinations at short intervals to maintain high antibody levels may be an effective strategy for protecting the elderly against COVID-19.


Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , SARS-CoV-2 , Vacinas de Produtos Inativados , Humanos , COVID-19/prevenção & controle , COVID-19/imunologia , Feminino , Masculino , Idoso , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/efeitos adversos , Vacinas contra COVID-19/administração & dosagem , SARS-CoV-2/imunologia , Estudos Prospectivos , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/sangue , Vacinas de Produtos Inativados/imunologia , Vacinas de Produtos Inativados/efeitos adversos , Vacinas de Produtos Inativados/administração & dosagem , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/sangue , Idoso de 80 Anos ou mais , Adulto , Vacinação , Estudos Longitudinais , Pessoa de Meia-Idade , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/administração & dosagem , Imunogenicidade da Vacina/imunologia , Imunização Secundária
13.
Asian J Androl ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38748861

RESUMO

ABSTRACT: Microdissection testicular sperm extraction (mTESE) is commonly performed to retrieve sperm in the testes for assisted reproductive techniques in patients with idiopathic nonobstructive azoospermia (iNOA). However, the success rate of sperm retrieval varies among individuals. We aim to investigate the association between clinical parameters and sperm retrieval outcomes in patients with iNOA. We searched PubMed, EMBASE, and Web of Science from database inception to August 2, 2023. The main measure was whether sperm retrieval was successful in patients with iNOA who underwent mTESE. Pooled estimates of the sperm retrieval rate and weighted mean differences were calculated using random-effects models. The overall sperm retrieval rate was 36.8% (95% confidence interval [CI]: 27.5%-46.0%, I2 = 95.0%) in nine studies comprising 1892 patients with iNOA. No significant differences were found in age, testicular volume, serum total testosterone concentrations, or inhibin B concentrations between positive and negative sperm retrieval outcomes. Lower anti-Müllerian hormone concentrations in patients with iNOA were associated with a positive outcome of mTESE (weighted mean differences: -2.70; 95% CI: -3.94--1.46, I2 = 79.0%). In conclusion, this study shows a significant relationship between anti-Müllerian hormone and sperm retrieval outcomes in patients with iNOA, while age, testicular volume, total testosterone, and inhibin B show no significant association. These findings have important implications for assessing the potential success of sperm retrieval and selecting appropriate treatment strategies in patients with iNOA.

14.
Exp Cell Res ; 439(1): 114089, 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38740166

RESUMO

Nucleus pulposus cells (NPCs) apoptosis and inflammation are the extremely critical factors of intervertebral disc degeneration (IVDD). Nevertheless, the underlying procedure remains mysterious. Macrophage migration inhibitory factor (MIF) is a cytokine that promotes inflammation and has been demonstrated to have a significant impact on apoptosis and inflammation. For this research, we employed a model of NPCs degeneration stimulated by lipopolysaccharides (LPS) and a rat acupuncture IVDD model to examine the role of MIF in vitro and in vivo, respectively. Initially, we verified that there was a significant rise of MIF expression in the NP tissues of individuals with IVDD, as well as in rat models of IVDD. Furthermore, this augmented expression of MIF was similarly evident in degenerated NPCs. Afterwards, it was discovered that ISO-1, a MIF inhibitor, effectively decreased the quantity of cells undergoing apoptosis and inhibited the release of inflammatory molecules (TNF-α, IL-1ß, IL-6). Furthermore, it has been shown that the PI3K/Akt pathway plays a vital part in the regulation of NPCs degeneration by MIF. Ultimately, we showcased that the IVDD process was impacted by the MIF inhibitor in the rat model. In summary, our experimental results substantiate the significant involvement of MIF in the degeneration of NPCs, and inhibiting MIF activity can effectively mitigate IVDD.

15.
Angew Chem Int Ed Engl ; : e202407613, 2024 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-38736299

RESUMO

Anion-exchange membrane fuel cells provide the possibility to use platinum group metal-free catalysts, but the anodic hydrogen oxidation reaction (HOR) suffers from sluggish kinetics and its source is still debated. Here, over nickel-tungsten (Ni-W) alloy catalysts, we show that the Ni:W ratio greatly governs the HOR performance in alkaline electrolyte. Experimental and theoretical studies unravel that alloying with W can tune the unpaired electrons in Ni, tailoring the potential of zero charge and the catalytic surface to favor hydroxyl adsorption (OHad). The OHad species coordinately interact with potassium (K+) ions, which break the K+ solvation sheath to leave free water molecules, yielding an improved connectivity of hydrogen-bond networks. Consequently, the optimal Ni17W3 alloy exhibits alkaline HOR activity superior to the state-of-the-art platinum on carbon (Pt/C) catalyst and operates steadily with negligible decay after 10,000 cycles. Our findings offer new understandings of alloyed HOR catalysts and will guide rational design of next-generation catalysts for fuel cells.

16.
Bioorg Chem ; 147: 107315, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38604017

RESUMO

Seven new meroterpenoids, paraphaeones A-G (1-7), and two new polyketides, paraphaeones H-I (8-9), along with eight known compounds (10-17), were isolated from the endophytic fungus Paraphaeosphaeria sp. C-XB-J-1. The structures of 1-9 were identified through the analysis of 1H, 13C, and 2D NMR spectra, assisted by HR-ESI-MS data. Compounds 1 and 7 exhibited a dose-dependent decrease in lactate dehydrogenase levels, with IC50 values of 1.78 µM and 1.54 µM, respectively. Moreover, they inhibited the secretion of IL-1ß and CASP-1, resulting in a reduction in the activity levels of NLRP3 inflammasomes. Fluorescence microscopy results indicated that compound 7 concentration-dependently attenuated cell pyroptosis. Additionally, compounds 4 and 7 showed potential inhibitory effects on the severe acute respiratory syndrome coronavirus-2 main protease (SARS-CoV-2 Mpro), with IC50 values of 10.8 ± 0.9 µM and 12.9 ± 0.7 µM, respectively.


Assuntos
Ascomicetos , Proteases 3C de Coronavírus , Policetídeos , SARS-CoV-2 , Terpenos , Policetídeos/química , Policetídeos/farmacologia , Policetídeos/isolamento & purificação , Ascomicetos/química , Humanos , Terpenos/química , Terpenos/farmacologia , Terpenos/isolamento & purificação , SARS-CoV-2/efeitos dos fármacos , Proteases 3C de Coronavírus/antagonistas & inibidores , Proteases 3C de Coronavírus/metabolismo , Proteases 3C de Coronavírus/química , Estrutura Molecular , Antivirais/farmacologia , Antivirais/química , Antivirais/isolamento & purificação , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Relação Dose-Resposta a Droga , Relação Estrutura-Atividade , Tratamento Farmacológico da COVID-19 , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/isolamento & purificação
18.
J Chem Phys ; 160(13)2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38577980

RESUMO

PtS2, a member of the group 10 transition metal dichalcogenides (TMDs), has received extensive attention because of its excellent electrical properties and air stability. However, there are few reports on the preparation of single-crystal PtS2 in the literature, and the growth mechanism of single crystal PtS2 is not well elucidated. In this work, we proposed a method of preparation that combines magnetron sputtering and chemical vapor transport to obtain monocrystalline PtS2 on a SiO2/Si substrate. By controlling the growth temperature and time, we have synthesized a single crystalline PtS2 of hexagonal shape and size of 1-2 µm on a silicon substrate. Combining the molecular dynamics simulation, the growth mechanism of single crystal PtS2 was investigated both experimentally and theoretically. The synthesis method has a short production cycle and low cost, which opens the door for the fabrication of other TMDs single crystals.

19.
Opt Express ; 32(6): 8959-8973, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38571141

RESUMO

In current optical systems, defocus blur is inevitable due to the constrained depth of field. However, it is difficult to accurately identify the defocus amount at each pixel position as the point spread function changes spatially. In this paper, we introduce a histogram-invariant spatial aliasing sampling method for reconstructing all-in-focus images, which addresses the challenge of insufficient pixel-level annotated samples, and subsequently introduces a high-resolution network for estimating spatially varying defocus maps from a single image. The accuracy of the proposed method is evaluated on various synthetic and real data. The experimental results demonstrate that our proposed model outperforms state-of-the-art methods for defocus map estimation significantly.

20.
Plant Biotechnol J ; 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38593377

RESUMO

Fusarium head blight (FHB) and the presence of mycotoxin deoxynivalenol (DON) pose serious threats to wheat production and food safety worldwide. DON, as a virulence factor, is crucial for the spread of FHB pathogens on plants. However, germplasm resources that are naturally resistant to DON and DON-producing FHB pathogens are inadequate in plants. Here, detoxifying bacteria genes responsible for DON epimerization were used to enhance the resistance of wheat to mycotoxin DON and FHB pathogens. We characterized the complete pathway and molecular basis leading to the thorough detoxification of DON via epimerization through two sequential reactions in the detoxifying bacterium Devosia sp. D6-9. Epimerization efficiently eliminates the phytotoxicity of DON and neutralizes the effects of DON as a virulence factor. Notably, co-expressing of the genes encoding quinoprotein dehydrogenase (QDDH) for DON oxidation in the first reaction step, and aldo-keto reductase AKR13B2 for 3-keto-DON reduction in the second reaction step significantly reduced the accumulation of DON as virulence factor in wheat after the infection of pathogenic Fusarium, and accordingly conferred increased disease resistance to FHB by restricting the spread of pathogenic Fusarium in the transgenic plants. Stable and improved resistance was observed in greenhouse and field conditions over multiple generations. This successful approach presents a promising avenue for enhancing FHB resistance in crops and reducing mycotoxin contents in grains through detoxification of the virulence factor DON by exogenous resistance genes from microbes.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...