Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Opt Express ; 31(24): 39747-39756, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-38041290

RESUMO

We proposed a "Ni sacrifice" method to fabricate Al-based highly reflective p-electrode in the ultraviolet spectral region for AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs). The "Ni sacrifice" p-electrode could have a high optical reflectivity of around 90% at the DUV spectral region below 300 nm. Compared to Ni/Au, indium tin oxide (ITO), and Pd p-contacts, the "Ni sacrifice" led to a higher resistivity of p-contacts and a slightly higher operated voltage of the DUV-LEDs (within 0.6 V at 20 mA). Although the electrical performance was degraded slightly, the light output power and external quantum efficiency of the DUV-LEDs could be improved by utilizing the "Ni sacrifice" p-electrode. Besides, we introduced a grid of vias in the device mesa and reduced the diameter of the vias to achieve an enhanced peak external quantum efficiency (EQE) up to 1.73%. And the wall-plug efficiency (WPE) of DUV-LEDs with a "Ni sacrifice" p-electrode was higher than that of Ni/Au p-electrode DUV-LEDs at low currents. These results highlight the great potential of the proposed "Ni sacrifice" reflective p-electrode for use in DUV-LEDs.

2.
J Pineal Res ; 73(2): e12810, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35620796

RESUMO

Melatonin (MT) functions in removing reactive oxygen species (ROS) and delaying plant senescence, thereby acting as an antioxidant; however, the molecular mechanism underlying the specific action of MT is unclear. Herein, we used the mutant plants carrying the MT decomposition gene melatonin 3-hydroxylase (M3H) in tomato to elucidate the specific mechanism of action of MT. SlM3H-OE accelerated senescence by decreasing the content of endogenous MT in plants. SlM3H is a senescence-related gene that positively regulates aging. MT inhibited the expression of the senescence-related gene SlCV to scavenge ROS, induced stable chloroplast structure, and delayed leaf senescence. Simultaneously, MT weakened the interaction between SlCV and SlPsbO/SlCAT3, reduced ROS production in photosystem II, and promoted ROS elimination. In conclusion, MT regulates ROS homeostasis and delays leaf aging in tomato plants through SlCV expression modulation.


Assuntos
Melatonina , Solanum lycopersicum , Regulação da Expressão Gênica de Plantas , Homeostase , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Melatonina/farmacologia , Folhas de Planta/genética , Senescência Vegetal , Espécies Reativas de Oxigênio/metabolismo
3.
Heliyon ; 10(1): e23638, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38187328

RESUMO

Somatic embryogenesis is a process of cell totipotency in vitro, whereby an embryogenic cell develops from vegetative tissues rather than from zygotes after double fertilization. Sorghum is a recalcitrant crop in genetic transformation; previous recipient systems have usually been from immature zygotic embryos, which needed more time and labors to prepare. Here, an efficient 2,4-dichlorophenoxyacetic acid (2,4-D)-induced somatic embryogenesis system from mature sorghum seeds was introduced. 2,4-D can induce two types of calli from a plumular axis section. Low-concentration 2,4-D (e.g., 2 mg/L) induces white and loose non-embryogenic calli (type 1), while high-concentration 2,4-D (e.g., 8 mg/L) induces yellow and compact embryogenic calli (type 2), which can be clearly distinguished by Sudan red staining. Germinating seeds have a long 2-day window for SE induction. Somatic embryogenesis can be enhanced by HDAC inhibitor, trichostatin A (TSA), a histone deacetylase treatment, which shows more SE productivity and a bigger size. Importantly, this easily prepared protocol does not show obvious genotype dependency in sorghum hybrids. In this study, a high-concentration 2,4-D-induced SE system was established from mature sorghum seeds. This finding provides a technical option for the genome editing recipient in sorghum.

4.
Neurol Sci ; 34(8): 1283-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23212403

RESUMO

Transcription factor (TF) and microRNA (miRNA) are two best characterized gene regulators that have been found to play an important role in gene regulation. However, high throughput screening the interaction relationships between transcription factors, microRNAs, and target genes in gliomas remains rare. Using GSE16666 and GSE13091 datasets downloaded from Gene Expression Omnibus data, we first screened the differentially expressed genes in gliomas. We explored the regulation relationship among TFs, miRNAs and target genes by different algorithms. The underlying molecular mechanisms of these crucial target genes were investigated by Gene Ontology function and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. Our study has developed three regulation relationships between two TFs and three miRNAs, including TP53/hsa-mir-155, TP53/hsa-mir-125b, and KLF2/hsa-mir-126. In addition, we also constructed a regulation network of the target genes by transcription factors and miRNAs. Some of them had been demonstrated to be involved in glioma progression via various pathways. For example, ATP2B2 target gene could be regulated by has-mir-181a to involve in calcium signaling pathway. RB1 could be regulated by has-miR-26a to participate in pathways in cancer. Smad7 could be regulated by has-miR-21 via intracellular TGF-ß signal transduction. We constructed a comprehensive regulatory network which was found to play an important role in gliomas progression.


Assuntos
Regulação Neoplásica da Expressão Gênica , Glioma/genética , MicroRNAs/metabolismo , Fatores de Transcrição/metabolismo , Expressão Gênica , Redes Reguladoras de Genes , Glioma/metabolismo , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Células Tumorais Cultivadas
5.
IEEE Trans Pattern Anal Mach Intell ; 45(7): 8920-8935, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37015400

RESUMO

Generative Adversarial Networks (GANs) typically suffer from overfitting when limited training data is available. To facilitate GAN training, current methods propose to use data-specific augmentation techniques. Despite the effectiveness, it is difficult for these methods to scale to practical applications. In this article, we present ScoreMix, a novel and scalable data augmentation approach for various image synthesis tasks. We first produce augmented samples using the convex combinations of the real samples. Then, we optimize the augmented samples by minimizing the norms of the data scores, i.e., the gradients of the log-density functions. This procedure enforces the augmented samples close to the data manifold. To estimate the scores, we train a deep estimation network with multi-scale score matching. For different image synthesis tasks, we train the score estimation network using different data. We do not require the tuning of the hyperparameters or modifications to the network architecture. The ScoreMix method effectively increases the diversity of data and reduces the overfitting problem. Moreover, it can be easily incorporated into existing GAN models with minor modifications. Experimental results on numerous tasks demonstrate that GAN models equipped with the ScoreMix method achieve significant improvements.

6.
Medicine (Baltimore) ; 101(11)2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35356918

RESUMO

BACKGROUND: Pei Yuan Tong Nao (PYTN) capsules has been widely used for the treatment of cerebrovascular disease, including cerebral infarction. However, the mechanisms of action of PYTN capsule on cerebral infarction are ambiguous and unclear. We conducted a protocol for systematic review and meta-analysis to evaluate the efficacy and safety of PYTN capsules for the treatment of cerebral infarction. METHODS: A comprehensive search of several databases from 1966 to February 2022 will be conducted. The databases includes Ovid Medline In-Process & Other NonIndexed Citations, Ovid MEDLINE, Ovid EMBASE, Ovid PsycINFO, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus. Two authors independently performed the literature searching, data extraction, and quality evaluation. The risk of bias in each included study will be assessed utilizing the Cochrane Collaboration's risk of bias tool. The Review Manager 5.3 (Cochrane Collaboration, Oxford, UK) will be used to analyze the data. RESULT: A synthesis of current evidence of PYTN capsules for cerebral infarction will be provided in this protocol. CONCLUSION: This review will provide more reliable references to help clinicians make decisions when dealing with cerebral infarction.


Assuntos
Infarto Cerebral , Medicamentos de Ervas Chinesas , Cápsulas , Infarto Cerebral/tratamento farmacológico , Medicamentos de Ervas Chinesas/uso terapêutico , Humanos , Metanálise como Assunto , Revisões Sistemáticas como Assunto
7.
Micromachines (Basel) ; 14(1)2022 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-36677072

RESUMO

GaN-based Micro-LED has been widely regarded as the most promising candidate for next generation of revolutionary display technology due to its advantages of high efficiency, high brightness and high stability. However, the typical micro-fabrication process would leave a great number of damages on the sidewalls of LED pixels, especially for Micro-LEDs, thus reducing the light emitting efficiency. In this paper, sidewall passivation methods were optimized by using acid-base wet etching and SiO2 layer passivation. The optical and electrical characteristics of optimized Micro-LEDs were measured and analyzed. The internal quantum efficiency (IQE) of Micro-LED was increased to 85.4%, and the reverse leakage current was reduced down to 10-13 A at -5 V. Optimized sidewall passivation can significantly reduce the non-radiative recombination centers, improving the device performance and supporting the development of high-resolution Micro-LED display.

8.
Artigo em Inglês | MEDLINE | ID: mdl-34520347

RESUMO

The emergence of Graph Convolutional Network (GCN) has greatly boosted the progress of graph learning. However, two disturbing factors, noise and redundancy in graph data, and lack of interpretation for prediction results, impede further development of GCN. One solution is to recognize a predictive yet compressed subgraph to get rid of the noise and redundancy and obtain the interpretable part of the graph. This setting of subgraph is similar to the information bottleneck (IB) principle, which is less studied on graph-structured data and GCN. Inspired by the IB principle, we propose a novel subgraph information bottleneck (SIB) framework to recognize such subgraphs, named IB-subgraph. However, the intractability of mutual information and the discrete nature of graph data makes the objective of SIB notoriously hard to optimize. To this end, we introduce a bilevel optimization scheme coupled with a mutual information estimator for irregular graphs. Moreover, we propose a continuous relaxation for subgraph selection with a connectivity loss for stabilization. We further theoretically prove the error bound of our estimation scheme for mutual information and the noise-invariant nature of IB-subgraph. Extensive experiments on graph learning and large-scale point cloud tasks demonstrate the superior property of IB-subgraph.

9.
World J Surg ; 33(12): 2651-6, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19760311

RESUMO

BACKGROUND: Gallbladder carcinoma (GC) is a highly lethal neoplasm. With the increase of cholecystectomies since the wide acceptance of laparoscopic cholecystectomy (LC), the incidental diagnosis of gallbladder carcinoma is more frequent. The aim of the present study was to report our experience with GC diagnosed during or after the performance of LC. METHODS: A total of 10,466 LCs were carried out from January 1999 to December 2007 in our hospital. Records of patients with incidental carcinoma were collected and analyzed retrospectively. RESULTS: Of all the patients, 20 (0.19%) were histopathologically diagnosed as having a GC. There were 4 men and 16 women; the median age in this group was 65.7 years (range: 37-81 years).The depth of cancer invasion was: pTis (4 cases), pT1a (2 cases), pT1b (2 cases), pT2 (6 cases), pT3 (4 cases), and pT4 (2 cases). The sensitivity and specificity of intraoperatively frozen section examination were 83.3 and 100%, respectively. Patients with in situ, pT1a and pT1b tumors underwent LC only, and there were no recurrences. The survival rate between patients with GC diagnosed during or after LC showed no difference; it was dependent on the depth of cancer invasion. CONCLUSIONS: The survival with incidental GC is related to stage, and it validates that a carefully performed LC is adequate treatment for carcinoma in situ, and stage 1a and b cancer. A frozen section examination was helpful but did not provide a definitive diagnosis. Meticulous techniques during LC, including retrieval of the gallbladder in a retrieval bag, may prevent port-site recurrence and intraperitoneal dissemination.


Assuntos
Neoplasias da Vesícula Biliar/cirurgia , Vesícula Biliar/patologia , Vesícula Biliar/cirurgia , Recidiva Local de Neoplasia/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Colecistectomia Laparoscópica , Feminino , Neoplasias da Vesícula Biliar/diagnóstico , Humanos , Achados Incidentais , Masculino , Pessoa de Meia-Idade , Prognóstico , Reoperação , Estudos Retrospectivos , Análise de Sobrevida
10.
Oxid Med Cell Longev ; 2019: 5294105, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31019652

RESUMO

Aberrant microRNA (miRNA) expressions contribute to the development and progression of various diseases, including Crohn's disease (CD). However, the accurate mechanisms of miRNAs in CD are definitely unclear. We employed colonic tissue samples from normal volunteers and CD patients, an acute mice colitis model induced by 2,4,6-trinitro-benzene-sulfonic acid (TNBS), and a cellular oxidative stress model induced by H2O2 in HT-29 cells to determine the effects of oxidative stress on expressions of miR-122, selenium-binding protein 1 (SELENBP1, SBP1), p65 nuclear factor κB (p65NF-κB) signaling, and DNA methylation. We found that SBP1 was mainly located on epithelial cells and was significantly increased in patients with active CD. SBP1 was the target gene of miR-122. miR-122 expression was downregulated while SBP1 expression was upregulated under TNBS-induced colitis or oxidative stress. Pre-miR-122 or siRNA SBP1 (si-SBP1) treatment ameliorated acute TNBS-induced colitis and H2O2-induced oxidative stress. Cotreatment of pre-miR-122 and si-SBP1 enhanced these effects. Besides, pre-miR-122 and si-SBP1 obviously activated the p65NF-κB signaling by phosphorylation of IκBα. Bisulfite sequencing of the CpG islands in the promoter region of miR-122 showed that CpG methylation was significantly increased under oxidative stress. Treating cells with 5'-AZA which was well known as a DNA-demethylating agent significantly increased miR-122 expression. Our results suggest that oxidative stress-induced DNA methylation of miR-122 aggravates colitis targeting SELENBP1 partially by p65NF-κB signaling and may promote the progression of CD.


Assuntos
Colite/genética , Colite/patologia , Metilação de DNA/genética , MicroRNAs/metabolismo , Estresse Oxidativo/genética , Proteínas de Ligação a Selênio/metabolismo , Animais , Sequência de Bases , Doença de Crohn/genética , Doença de Crohn/patologia , Regulação para Baixo/genética , Células HT29 , Humanos , Peróxido de Hidrogênio/toxicidade , Camundongos , MicroRNAs/genética , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais , Ácido Trinitrobenzenossulfônico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA