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1.
BMC Infect Dis ; 21(1): 951, 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34521370

RESUMO

BACKGROUND: The coronavirus disease 2019 (COVID-19) has caused a global pandemic, resulting in considerable mortality. The risk factors, clinical treatments, especially comprehensive risk models for COVID-19 death are urgently warranted. METHODS: In this retrospective study, 281 non-survivors and 712 survivors with propensity score matching by age, sex, and comorbidities were enrolled from January 13, 2020 to March 31, 2020. RESULTS: Higher SOFA, qSOFA, APACHE II and SIRS scores, hypoxia, elevated inflammatory cytokines, multi-organ dysfunction, decreased immune cell subsets, and complications were significantly associated with the higher COVID-19 death risk. In addition to traditional predictors for death risk, including APACHE II (AUC = 0.83), SIRS (AUC = 0.75), SOFA (AUC = 0.70) and qSOFA scores (AUC = 0.61), another four prediction models that included immune cells subsets (AUC = 0.90), multiple organ damage biomarkers (AUC = 0.89), complications (AUC = 0.88) and inflammatory-related indexes (AUC = 0.75) were established. Additionally, the predictive accuracy of combining these risk factors (AUC = 0.950) was also significantly higher than that of each risk group alone, which was significant for early clinical management for COVID-19. CONCLUSIONS: The potential risk factors could help to predict the clinical prognosis of COVID-19 patients at an early stage. The combined model might be more suitable for the death risk evaluation of COVID-19.

2.
Phys Chem Chem Phys ; 23(35): 19457-19464, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34524283

RESUMO

Reactive force field (ReaxFF) is a powerful computational tool for exploring material properties. In this work, we proposed an enhanced reactive force field model, which uses message passing neural networks (MPNN) to compute the bond order and bond energies. MPNN are a variation of graph neural networks (GNN), which are derived from graph theory. In MPNN or GNN, molecular structures are treated as a graph and atoms and chemical bonds are represented by nodes and edges. The edge states correspond to the bond order in ReaxFF and are updated by message functions according to the message passing algorithms. The results are very encouraging; the investigation of the potential, such as the potential energy surface, reaction energies and equation of state, are greatly improved by this simple improvement. The new potential model, called reactive force field with message passing neural networks (ReaxFF-MPNN), is provided as an interface in an atomic simulation environment (ASE) with which the original ReaxFF and ReaxFF-MPNN potential models can do MD simulations and geometry optimizations within the ASE. Furthermore, machine learning, based on an active learning algorithm and gradient optimizer, is designed to train the model. We found that the active learning machine not only saves the manual work to collect the training data but is also much more effective than the general optimizer.

3.
Artigo em Inglês | MEDLINE | ID: mdl-34494432

RESUMO

The band gap engineering of two-dimensional (2D) transition metal dichacogenides (TMDs) could significantly broaden their applications, especially in electronics and optoelectronics. Alloying is a more effective approach to synthesize 2D ternary TMD materials with tunable bandgaps by regulating the compositions. Whether the alloying could induce memory effects is of interest as a scientific problem and worthy to be studied. A thermal evaporation-assisted chemical vapor deposition (CVD) method was proposed to grow millimeter size gradient alloyed monolayer Mo1-xWxS2. This method reveals a promising and universal methodology for the development of gradient alloyed TMDs because of the precise controlling of each precursor. The synthesized Mo1-xWxS2 monolayer crystal has a gradient composition with x ranging from 0.1 to 1. The W and Mo atoms homogeneously alloyed with random distribution in the Mo1-xWxS2 monolayer. As reported, the deep energy levels induced by sulfur vacancies can be effectively suppressed to shallow energy levels by alloying TMDs. The series distribution of the shallow energy levels in the band of the graded alloy semiconductor can act as multiple charge trapping states, which leads to obvious memory effects in the device. These results present a new opportunity for memory devices and related applications.

4.
Artigo em Inglês | MEDLINE | ID: mdl-34487206

RESUMO

The dietary supplementation of prebiotics is considered a promising strategy for the modulation of gut microbiota. Due to the wide variety of animal models and tremendous inter-individual variability from human investigations, the prebiotic effect of fibers is often difficult to compare between studies. Here, the effects of 11 dietary fibers on human fecal microbiota were studied using an in vitro human fecal fermentation model under well-controlled conditions. All fibers showed positive regulatory effects on short chain fatty acids (SCFAs) and several beneficial bacteria, including Parabacteroides distasonis and Bifidobacterium spp. Cultures supplemented with xylo-oligosaccharide and konjac flour showed the highest SCFAs. According to regulatory effects, fibers were divided into three groups, with 13 indicator OTUs (operational taxonomic units) identified. Fecal microbiota regulated by isomalto-oligosaccharide and chitosan-oligosaccharide were similar to fructo-oligosaccharide and inulin outputs. As a supplement to in vivo studies, our results comprehensively summarized the similarities and distinctiveness of fibers in regulating fecal microbiota structures. KEY POINTS: • Fibers were divided into three groups based on the regulatory effects in microbiota. • Thirteen indicator OTUs were identified using pairwise comparisons. • Fiber similarities and distinctive traits in regulating microbiota effect were identified.

6.
Environ Pollut ; 290: 118062, 2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34482246

RESUMO

A highly efficient, eco-friendly and relatively low-cost catalyst is necessary to tackle bottlenecks in the treatment of industrial wastewater laden with heavy metals and antibiotic such as livestock farm and biogas liquids. This study investigated co-oxidative removal of arsenite (As(III)) and tetracycline (TC) by iron nanoparticles (Fe NP)-impregnated carbons based on heterogeneous Fenton-like reactions. The composites included Fe NP@biochar (BC), Fe NP@hydrochar (HC), and Fe NP@HC-derived pyrolysis char (HDPC). The functions of N and S atoms and the loading mass of the Fe NP in the Fe NP@BC in heterogeneous Fenton-like reactions were studied. To sustain its cost-effectiveness, the spent Fe NP@BC was regenerated using NaOH. Among the composites, the Fe NP@BC achieved an almost complete removal of As(III) and TC under optimized conditions (1.0 g/L of dose; 10 mM H2O2; pH 6; 4 h of reaction; As(III): 50 µM; TC: 50 µM). The co-oxidative removal of As(III) and TC by the Fe NP@ BC was controlled by the synergistic interactions between the Fe NPs and the active N and S sites of the BC for generating reactive oxygen species (ROS). After four consecutive regeneration cycles, about 61 and 95% of As(III) and TC removal were attained. This implies that the spent carbocatalyst still has reasonable catalytic activities for reuse. Overall, this suggests that adding technological values to unused biochar as a carbocatalyst like Fe NP@BC was promising for co-oxidative removal of As(III) and TC from contaminated water.

7.
Pathol Oncol Res ; 27: 1609844, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34483751

RESUMO

Vasculogenic mimicry (VM) has been identified as an important vasculogenic mechanism in malignant tumors, but little is known about its clinical meanings and mechanisms in oligodendroglioma. In this study, VM-positive cases were detected in 28 (20.6%) out of 136 oligodendroglioma samples, significantly associated with higher WHO grade, lower Karnofsky performance status (KPS) scores, and recurrent tumor (p < 0.001, p = 0.040, and p = 0.020 respectively). Patients with VM-positive oligodendroglioma had a shorter progress-free survival (PFS) compared with those with VM-negative tumor (p < 0.001), whereas no significant difference was detected in overall survival (OS) between these patients. High levels of phosphorylate serine/threonine kinases Ataxia-telangiectasia mutated (pATM) and phosphorylate Ataxia-telangiectasia and Rad3-Related (pATR) were detected in 31 (22.8%) and 34 (25.0%), respectively out of 136 oligodendroglioma samples. Higher expressions of pATM and pATR were both associated with a shorter PFS (p < 0.001 and p < 0.001). VM-positive oligodendroglioma specimens tended to exhibit higher pATM and pATR staining than VM-negative specimens (rs = 0.435, p < 0.001 and rs = 0.317, p < 0.001). Besides, Hypoxia-inducible factor-1α (HIF1α) expression was detected in 14(10.3%) samples, correlated with higher WHO grade and non-frontal lobe (p = 0.010 and p = 0.029). However, no obvious connection was detected between HIF1α expression and VM formation (p = 0.537). Finally, either univariate or multivariate analysis suggested that VM was an independent unfavorable predictor for oligodendroglioma patients (p < 0.001, HR = 7.928, 95%CI: 3.382-18.584, and p = 0.007, HR = 4.534, 95%CI: 1.504-13.675, respectively). VM is a potential prognosticator for tumor progression in oligodendroglioma patients. Phosphorylation of ATM and ATR linked to treatment-resistance may be associated with VM formation. The role of VM in tumor progression and the implication of pATM/pATR in VM formation may provide potential therapeutic targets for oligodendroglioma treatment.

8.
Phys Rev Lett ; 127(10): 108101, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34533352

RESUMO

We investigate the rheological properties of interpenetrating networks reconstituted from the main cytoskeletal components: filamentous actin, microtubules, and vimentin intermediate filaments. The elastic modulus is determined largely by actin, with little contribution from either microtubules or vimentin. However, vimentin dramatically impacts the relaxation, with even small amounts significantly increasing the relaxation time of the interpenetrating network. This highly unusual decoupling between dissipation and elasticity may reflect weak attractive interactions between vimentin and actin networks.

9.
Am J Emerg Med ; 2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34474943

RESUMO

Alcoholic ketoacidosis (AKA) lacks specific clinical presentation. The results of blood testing commonly show hemoconcentration, elevated ß-hydroxybutyrate levels, and acidosis in patients with AKA. Herein, we report a case of AKA accompanied by hyperglycemia and review the related literature. Case report: AKA associated with hyperglycemia is rare, and its pathogenesis is similar to that of diabetic ketoacidosis, thereby making differentiation challenging. Accordingly, AKA is easily misdiagnosed by endocrinologists. The main symptoms of a 37-year-old female included hyperglycemia, elevated ß-hydroxybutyrate levels, and metabolic acidosis. Primary clinical presentations were severe nausea and vomiting. The patient initially diagnosed with DKA were eventually confirmed as AKA, who recovered after active therapy with rehydration and correction of hyperglycemia, electrolyte imbalance, and ketosis. This study provides a reference for clinicians to reduce missed diagnosis and the misdiagnosis rates of AKA.

10.
Virus Res ; 304: 198549, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34425164

RESUMO

Enterovirus D68 (EV-D68) belongs to the Picornaviridae family and can lead to severe clinical manifestations in the respiratory system. The 3D-polymerase (3Dpoly) is an important nonstructural protein during EV-D68 replication, but few studies have addressed its interaction with the host antiviral response during EV-D68 infection. Here, we used human bronchial epithelial cells to investigate the impact of the 3Dpoly on the mitochondrial dynamics and innate immune response. The results showed that the number and morphology of the mitochondria in 16HBE cells was affected during the early stage of infection, and these effects included the cellular apoptosis. Moreover, we found that the 3Dpoly of EV-D68 can interact with PGAM5 and promote mitofusin 2 protein upregulation, and subsequently, 3Dpoly impairs IFN-ß expression by impacting the activation of the RIG-I receptor signaling pathway. Our findings suggest that during EV-D68 replication, the 3Dpoly, via its interaction with PGAM5, can affect the mitochondrial dynamics and suppress the expression of IFN-ß by impacting the RIG-I-like receptor signal pathway.

11.
Artigo em Inglês | MEDLINE | ID: mdl-34444218

RESUMO

The construction sector is recognized as one of the most dangerous industries in the world. The situation is worsening in Iraq, as a result of a lack of attention to safety in the building industry and the poor implementation of safety programs. This research aims to identify the critical safety factors (CSFs) of safety program implementation in the Iraqi construction industry. The CSFs were first identified from a review of literature before being verified by construction practitioners, using semi-structured interviews. A questionnaire, based on the verified CSFs, was distributed to construction practitioners in Iraq. Exploratory factor analysis (EFA) was used to analyze the quantitative data, and the results show that the CSFs can be categorized into four constructs: worker involvement, safety prevention and control system, safety arrangement, and management commitment. Following that, partial least square structural equation modelling (PLS-SEM) was executed to establish the connection between safety program implementation and overall project success. The result confirms that safety program implementation has a significant, positive impact on project success. This article contributes to knowledge and practice by identifying the CSFs for implementing safety programs in the Iraqi construction industry. The successful implementation of a safety program not only improves safety performance, but also helps to meet other project goals.


Assuntos
Indústria da Construção , Análise Fatorial , Iraque , Inquéritos e Questionários
12.
Int Immunopharmacol ; 99: 108051, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34426110

RESUMO

Hepatic fibrosis represents as a dynamic pathological process characterized by the net accumulation of extracellular matrix in the progression of various chronic liver diseases, including viral hepatitis, alcoholic liver disease, and metabolic associated fatty liver disease (MAFLD). Activation of hepatic stellate cells (HSCs) is well-defined to play a central role in the initiation and progression of hepatic fibrosis. However, the activation of HSCs is affected by the complicated microenvironments in liver, which largely attributes to the communication between hepatocytes and multiple tissue-resident cells, including sinusoidal endothelial cells, bile duct epithelial cells, platelets, T cells, B cells, macrophages, natural killer cells, neutrophils, dendritic cells, in the direct or indirect mechanisms. Cellular crosstalk between HSCs and surrounding cells contributes to the activation of HSCs and the progression of hepatic fibrosis. Currently, accumulating evidence have proven the complexity and plasticity of HSCs activation, and further clarification of cellular communication between HSCs and surrounding cells will provide sufficient clue to the development of novel diagnostic methods and therapeutic strategies for hepatic fibrosis.

13.
Chin J Integr Med ; 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34432200

RESUMO

OBJECTIVE: To evaluate the protective effects of Astragaloside IV (AST) in a rat model of myocardial injury induced by cecal ligation and puncture (CLP). METHODS: The model of sepsis-induced cardiac dysfunction was induced by CLP. Using a random number table, 50 specific pathogen free grade of Sprague Dawley rats were randomized into 5 groups: the sham group (sham), the model group (CLP, 18 h/72 h) and AST group (18 h/72 h). Except the sham group, the rats in other groups received CLP surgery to induce sepsis. CLP groups received intragastric administration with normal saline after CLP. AST groups received intragastric administration with AST solution (40 mg/kg) once a day. The levels of inflammatory mediators and oxidative stress markers in the serum of the septic rats were determined via enzyme-linked immunosorbent assay (ELISA) at different time point, such as interleukin 6 (IL-6), IL-10, high mobility group box-1 protein B1 (HMGB-1), superoxide dismutase (SOD), and malondialdehyde (MDA). Cardiac function was determined by echocardiography. Moreover, changes in myocardial pathology were evaluated using hematoxylin and eosin staining. The levels of lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) were analysed to determine the status of CLP-induced myocardium. In addition, the apotosis of myocardial cells was analysed by terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL). The protein levels of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X (Bax), IκB kinase α (IKKα), nuclear factor kappa B p65 (NF-κB p65) were detected by Western blot analysis. Moreover, survival rate was investigated. RESULTS: AST improved the survival rate of CLP-induced rats by up to 33.3% (P<0.05). The cardioprotective effect of AST was observed by increased ejection fraction, fractional shortening and left ventricular internal diameter in diastole respectively (P<0.01 or P<0.05). Subsequently, AST attenuated CLP-induced myocardial apoptosis and the ratio of Bcl-2/Bax in the myocardium, as well as the histological alterations of myocardium (P<0.01 or P<0.05); the generation of inflammatory cytokines (IL-6, IL-10, HMGB-1) and oxidative stress markers (SOD, MDA) in the serum was significantly alleviated (P<0.01 or P<0.05). On the other hand, AST markedly suppressed CLP-induced accumulation of IKK-α and NF-κB p65 subunit phosphorylation (P<0.01 or P<0.05). CONCLUSIONS: AST plays a significant protective role in sepsis-induced cardiac dysfunction and survival outcome. The possible mechanism of cardioprotection is dependent on the activation of the IKK/NF-κB pathway in cardiomyocytes.

14.
Int J Radiat Biol ; : 1-6, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34402381

RESUMO

PURPOSE: This study assesses changes of circulating leukocyte subpopulations and the expression of checkpoint receptors in T cells in patients undergoing radiochemotherapy. MATERIALS AND METHODS: Fifty-seven patients with either esophageal cancer or cervical cancer who received radiochemotherapy were recruited into this study. Serial blood collection was carried out before and during treatments. Leukocyte subpopulations and the level of PD-1 and CTLA-4 in T cells were determined by flow cytometry. The plasma concentrations of 34 human cytokines, chemokines, and growth factors were quantified. RESULTS: Significant decreases of lymphocyte count and percentage of T cells and B cells were observed during radiochemotherapy. Percentages of PD-1hi and CTLA-4hi populations in T cells increased after treatments. Proportion of activated T cells showed no significant difference. No significant changes in the plasma concentrations of the 34 humoral mediators except mild decreases of six cytokines. CONCLUSION: Elevated expression of PD-1 and CTLA-4 in T cells in patients receiving radiochemotherapy, which suggests that exhaustion-like T-cell dysfunction develops during cancer cytotoxic treatments.

15.
Anim Biotechnol ; : 1-8, 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34353209

RESUMO

Endoplasmic reticulum stress (ERS) plays an important role in regulating the reproductive process of female mammals, mainly involved in follicular atresia and corpus luteum regression. DNA damage induced transcript 3 (DDIT3) is a marker gene of ERS. The objectives of the present study were to clone and analyze the sequence and tissue expression characteristics of DDIT3 gene in female yaks. By reverse transcriptase-polymerase chain reaction (RT-PCR) strategy, we obtained full-length 507-bp DDIT3-cDNA, encoding for 168-aa protein. Yak DDIT3 exhibited highest and least identity with that of bison and horse, respectively. Real-time PCR analyses revealed that the expression level of DDIT3 gene in ovary was higher than that in heart, liver, kidney, spleen, lung, uterus and oviduct (p < 0.05). DDIT3 expression level in ovary and uterus during pregnancy was higher than that in follicular phase, luteal phase and fetus stage. DDIT3 was highly expressed in metaphase II oocytes and granulosa cells than that in germinal vesicle and metaphase I oocytes (p < 0.05), respectively. This is the first molecular characterization and expression patterns of DDIT3 gene in female yaks. These results indicated that the DDIT3 gene possibly plays an important role in regulating ovary function and pregnancy maintenance in yaks.

16.
BMC Immunol ; 22(1): 54, 2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34380427

RESUMO

BACKGROUND: Both hepatitis C virus (HCV) infection and adiponectin are critically involved in metabolism. The reversal and associations of altering adiponectin levels after sustained virological responses (SVRs) following direct-acting antivirals (DAA) in HCV-infected patients remained elusive. METHODS: A joint study was conducted in a prospective cohort of 427 HCV-infected patients and a line of HCV core transgenic mice. RESULTS: Of 427, 358 had completed a course of DAA therapy and 353 had SVRs. At baseline, male sex (95% CI ß: - 1.44 to - 0.417), estimated glomerular filtration rate (eGFR) (- 0.025 to - 0.008), triglycerides (- 0.015 to - 0.005), and fibrosis-4 levels (0.08-0.297) were associated with adiponectin levels; BMI (0.029-0.327) and triglycerides levels (0.01-0.03) were associated with homeostatic model assessment for insulin resistance (HOMA-IR) in HCV-infected patients. At 24-week post-therapy, in SVR patients, male sex (- 1.89 to - 0.5) and eGFR (- 0.02 to - 0.001) levels were associated with adiponectin levels, levels of BMI (0.094-0.335) and alanine transaminase (0.018-0.078) were associated with HOMA-IR; compared with baseline levels, adiponectin levels decreased (6.53 ± 2.77 vs. 5.45 ± 2.56 µg/mL, p < 0.001). In 12-month-old HCV core transgenic mice with hepatic steatosis, triglyceride levels (0.021-0.111) were associated with adiponectin levels, and hepatic adipopnectin expression was comparable with that of control mice. CONCLUSIONS: Triglycerides and hepatic fibrosis are associated with HCV-specific alteration of adiponectin levels, and adiponectin may affect insulin sensitivity through triglycerides during HCV infection. In DAA-treated patients, after SVR, adiponectin levels decreased and the linking function of triglycerides between adiponectin and insulin sensitivity vanished. Moreover, HCV core with hepatic steatosis might affect extrahepatic adiponectin expression through triglycerides.

17.
Artigo em Inglês | MEDLINE | ID: mdl-34462721

RESUMO

Because of the relatively limited understanding of COVID-19 pathogenesis, immunological analysis for vaccine development is needed. Mice and macaques were immunized with an inactivated SARS-CoV-2 vaccine prepared by two inactivators. Various immunological indexes were tested, and viral challenges were performed on day 7 or 150 after booster immunization in monkeys. This inactivated SARS-CoV-2 vaccine was produced by sequential inactivation with formaldehyde followed by propiolactone. The various antibody responses and specific T cell responses to different viral antigens elicited in immunized animals were maintained for longer than 150 days. This comprehensive immune response could effectively protect vaccinated macaques by inhibiting viral replication in macaques and substantially alleviating immunopathological damage, and no clinical manifestation of immunopathogenicity was observed in immunized individuals during viral challenge. This candidate inactivated vaccine was identified as being effective against SARS-CoV-2 challenge in rhesus macaques.

18.
Eur Spine J ; 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34392419

RESUMO

OBJECTIVE: We focus on providing the first comprehensive national dataset on the incidence, injury aetiology and mortality of TSCI in China. METHODS: A multi-stage stratified cluster sampling method was used. We included TSCI cases from all hospitals in three regions, nine provinces and 27 cities in China via search of electronic medical records and retrospectively analysed the characteristics of TSCI in China from 2009 to 2018. We estimated the incidence of TSCI in the total population and subgroups. RESULTS: There were 5954 actual cases in 2009, corresponding to a total estimated TSCI incidence of 45.1 cases per million population (95% CI, 44.0-46.3). There were 10,074 actual cases in 2018, corresponding to a total estimated TSCI incidence of 66.5 cases per million population (95% CI, 65.2-67.8) (P < 0.001; annual average percentage change (AAPC), 4.4%). From 2009 to 2018, the incidence of almost all sex/age groups showed an increasing trend over time (P < 0.001; AAPC, 0.7-8.8%). The elderly population (aged 65-74) displayed the highest incidence of TSCI (with an average annual incidence of 127.1 cases per million [95% CI, 119.8-134.3]). CONCLUSIONS: The TSCI incidence increased significantly from 2009 to 2018. The incidence in the elderly populations was consistently high and continues to increase over time. The mortality of TSCI patients in hospitals is relatively low and continues to decrease each year, but elderly individuals remain at a high risk of hospital death.

19.
Adv Sci (Weinh) ; : e2101106, 2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34390217

RESUMO

The growing demand for scalable solar-blind image sensors with remarkable photosensitive properties has stimulated the research on more advanced solar-blind photodetector (SBPD) arrays. In this work, the authors demonstrate ultrahigh-performance metal-semiconductor-metal (MSM) SBPDs based on amorphous (a-) Ga2 O3 via a post-annealing process. The post-annealed MSM a-Ga2 O3 SBPDs exhibit superhigh sensitivity of 733 A/W and high response speed of 18 ms, giving a high gain-bandwidth product over 104 at 5 V. The SBPDs also show ultrahigh photo-to-dark current ratio of 3.9 × 107 . Additionally, the PDs demonstrate super-high specific detectivity of 3.9 × 1016 Jones owing to the extremely low noise down to 3.5 fW Hz-1/2 , suggesting high signal-to-noise ratio. Underlying mechanism for such superior photoelectric properties is revealed by Kelvin probe force microscopy and first principles calculation. Furthermore, for the first time, a large-scale, high-uniformity 32 × 32 image sensor array based on the post-annealed a-Ga2 O3 SBPDs is fabricated. Clear image of target object with high contrast can be obtained thanks to the high sensitivity and uniformity of the array. These results demonstrate the feasibility and practicality of the Ga2 O3 PDs for applications in solar-blind imaging, environmental monitoring, artificial intelligence and machine vision.

20.
Artif Organs ; 45(10): 1141-1154, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34318520

RESUMO

A visual prosthesis is an auxiliary device for patients with blinding diseases that cannot be treated with conventional surgery or drugs. It converts captured images into corresponding electrical stimulation patterns, according to which phosphenes are generated through the action of internal electrodes on the visual pathway to form visual perception. However, due to some restrictions such as the few implantable electrodes that the biological tissue can accommodate, the induced perception is far from ideal. Therefore, an important issue in visual prosthesis research is how to detect and present useful information in low-resolution prosthetic vision to improve the visual function of the wearer. In recent years, with the development and broad application of computer vision methods, researchers have investigated the possibility of their utilization in visual prostheses by simulating prosthetic visual percepts. Through the optimization of visual perception by image processing, the efficiency of visual prosthesis devices can be further improved to better meet the needs of prosthesis wearers. In this article, recent works on prosthetic vision centering on implementing computer vision methods are reviewed. Differences, strengths, and weaknesses of the mentioned methods are discussed. The development directions of optimizing prosthetic vision and improving methods of visual perception are analyzed.

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