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1.
Compr Psychiatry ; : 152182, 2020 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-32430143

RESUMO

BACKGROUND: Some bereaved parents experience a decreasing trajectory of grief, while others fail to adapt over the long term and persistently suffer from negative health consequences. This study investigates the mediating role of social integration in the relationship between losing an only child and parental health in a family-oriented society. METHOD: A sample of 1828 bereaved parents and 4739 non-bereaved parents was drawn from a 10-city survey in China. Regression methods were used to examine the impact of child loss on parental health, and Sobel test was applied to examine the mediating role of social integration. RESULTS: Bereaved parents who lost their only child have worse self-rated health and more negative affect than the non-bereaved parents, which lasted for years after the death of the only child. The Sobel test shows that 24.8% of the total effects on self-rated health and 6.7% of the total effects on negative affect can be explained via decreased social integration. The gender of parents and child as well as fertility intentions are important sources of heterogeneity in the Chinese culture. LIMITATION: The results based on cross-sectional data may only reveal correlation rather than causality. The data was retrieved from self-reported questionnaires and there is a lack of objective measures of parental health. Moreover, the detailed mechanisms behind how child loss resulted in less social integration should be further explored. CONCLUSIONS: Significant disparities in health outcomes and social integration were found for bereaved parents relative to the non-bereaved parents. Future work is needed to assess the health of bereaved parents, identify the vulnerable and disadvantaged groups, and design inclusive intervention programs.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32451257

RESUMO

The outbreak of coronavirus disease 2019 (COVID-19) characterized with pneumonia, firstly occurred in Wuhan city, China, in December 2019 has so far spread in over 200 countries and territories in the world. One of the important goals in facing outbreaks of COVID-19 is to reduce the case fatality rate. We reported here that the fatality rate of COVID-19 in other provinces of mainland China was 0.82% (121/14,708), significantly lower than 6.62% (4512/68,128) in Hubei province (p<0.0001). The main reason for the lower fatality rate was likely due to the timely management of the patients in other provinces, highlighting the importance of timely management of patients in reducing the fatality rate of COVID-19.

3.
Adv Biosyst ; : e2000037, 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32419296

RESUMO

Sepsis is a life-threatening inflammatory disease with a high mortality rate and huge implicative costs. Lipopolysaccharide (LPS) from gram-negative bacteria activates toll-like receptor 4 (TLR4) and may trigger septic shock. However, potent TLR4 inhibitors TAK-242 and Eritoran have been terminated in phase III clinical trials because of inadequate efficacy. Inspired by the recently discovered intracellular, noncanonical LPS receptors, it is considered that TLR4-mediated canonical and caspase-mediated noncanonical inflammation can be seen as a "parallel circuit" to induce sepsis and endotoxemia. Logically, it is proposed that the dual inhibition of caspase-4/5/11 and TLR4 can be a potential novel strategy to develop new therapeutics for sepsis. To verify the strategy, two potential compounds are found: Luteolin and Diacerein with substantial antiinflammatory activity in vitro and in vivo. The results show that the survival rate of endotoxemic mice treated by these compounds is increased remarkably. LPS-induced organ damage is also prevented. Moreover, these compounds result in physical and mental recovery for endotoxemic mice. Notably, Luteolin exhibits better antiinflammatory activity than TAK-242 at comparable TLR4-inhibitory levels. These findings indicate that simultaneous inhibition of TLR4 and caspase-4/5/11 can be an anticipative strategy defeating sepsis and endotoxemia, which can be translated into significant medical and economic benefits.

4.
Sci Rep ; 10(1): 7717, 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32382050

RESUMO

The present study aimed to explore the value of intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) in differentiating hepatocellular carcinoma (HCC) from intrahepatic cholangiocarcinoma (ICC). This study included 65 patients with malignant hepatic nodules (55 with HCC, 10 with ICC), and 17 control patients with normal livers. All patients underwent IVIM-DWI scans on a 3.0 T magnetic resonance imaging (MRI) scanner. The standard apparent diffusion coefficient (ADC), pure diffusion coefficient (Dslow), pseudo-diffusion coefficient (Dfast), and perfusion fraction (f) were obtained. Differences in the parameters among the groups were analysed using one-way ANOVA, with p < 0.05 indicating statistical significance. Receiver operating characteristic (ROC) curve analysis was used to compare the efficacy of each parameter in differentiating HCC from ICC. ADC, Dslow, Dfast, f significantly differed among the three groups. ADC and Dslow were significantly lower in the HCC group than in the ICC group, while Dfast was significantly higher in the HCC group than in the ICC group; f did not significantly differ between the HCC and ICC groups. When the cut-off values of ADC, Dslow, and Dfast were 1.27 × 10-3 mm2/s, 0.81 × 10-3 mm2/s, and 26.04 × 10-3 mm2/s, respectively, their diagnostic sensitivities for differentiating HCC from ICC were 98.18%, 58.18%, and 94.55%, their diagnostic specificities were 50.00%, 80.00%, and 80.00%, and their areas under the ROC curve (AUCs) were 0.687, 0.721, and 0.896, respectively. Dfast displayed the largest AUC value. IVIM-DWI can be used to differentiate HCC from ICC.

5.
Theor Appl Genet ; 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32405768

RESUMO

KEY MESSAGE: An effective and stable quantitative resistance locus, QSc.VR4, was fine mapped, characterized and physically anchored to the short arm of 4H, conferring adult plant resistance to the fungus Rhynchosporium commune in barley. Scald caused by Rhynchosporium commune is one of the most destructive barley diseases worldwide. Accumulation of adult plant resistance (APR) governed by multiple resistance alleles is predicted to be effective and long-lasting against a broad spectrum of pathotypes. However, the molecular mechanisms that control APR remain poorly understood. Here, quantitative trait loci (QTL) analysis of APR and fine mapping were performed on five barley populations derived from a common parent Vlamingh, which expresses APR to scald. Two QTLs, designated QSc.VR4 and QSc.BR7, were detected from a cross between Vlamingh and Buloke. Our data confirmed that QSc.VR4 is an effective and stable APR locus, residing on the short arm of chromosome 4H, and QSc.BR7 derived from Buloke may be an allele of reported Rrs2. High-resolution fine mapping revealed that QSc.VR4 is located in a 0.38 Mb genomic region between InDel markers 4H2282169 and 4H2665106. The gene annotation analysis and sequence comparison suggested that a gene cluster containing two adjacent multigene families encoding leucine-rich repeat receptor kinase-like proteins (LRR-RLKs) and germin-like proteins (GLPs), respectively, is likely contributing to scald resistance. Adult plant resistance (APR) governed by QSc.VR4 may confer partial levels of resistance to the fungus Rhynchosporium commune and, furthermore, be an important resource for gene pyramiding that may contribute broad-based and more durable resistance.

6.
Ann Transl Med ; 8(7): 519, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32395563

RESUMO

[This corrects the article DOI: 10.21037/atm.2019.11.106.].

8.
Metabolism ; 108: 154258, 2020 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-32376130

RESUMO

RATIONALE: Tubulointerstitial fibrosis, which is closely related to functional injury of the kidney, can be observed in advanced stages of diabetic nephropathy (DN). Mammalian serine/threonine-protein kinase 4 (MST1), a core component of the Hippo pathway that is involved in cellular proliferation and differentiation, plays a crucial role in the pathogenesis of multiple metabolic diseases, kidney diseases and cancer. METHODS: In type 1 and type 2 diabetic animals, as well as in human proximal tubular epithelial cells (HK-2), activation of MST1 was analyzed by immunohistochemistry and western blotting. In db/db mice, MST1 protein was knocked down or overexpressed by shRNA, and renal function, fibrosis, and downstream signaling were then investigated. RNA silencing and overexpression were performed by using an MST1 or YAP knockdown/expression lentivirus to investigate the regulation of MST1-mediated YAP/TEAD signaling pathways in the fibrosis process in HK-2 cells. Luciferase and coimmunoprecipitation (co-IP) assays were used to identify whether YAP directly regulated TEAD activation by forming a YAP-TEAD heterodimer, which ultimately leads to tubulointerstitial fibrosis. RESULTS: MST1 activation was significantly decreased in type 1 and type 2 diabetic nephropathy. Notably, the downregulation of MST1 activation was also observed in HK-2 cells in a glucose- and time-dependent manner. In vivo, downregulation of MST1 was sufficient to promote renal dysfunction and fibrosis in db/m mice, whereas overexpression of MST1 ameliorated diabetic nephropathy-induced renal fibrosis. Further mechanistic study demonstrated that activated YAP induced by MST1 inhibition directly upregulated TEAD activation by binding to TEAD and forming a YAP-TEAD heterodimer, resulting in the promotion of epithelial-mesenchymal transition (EMT) and fibrosis in renal tubular epithelial. CONCLUSIONS: MST1 activation represents a potential therapeutic strategy to treat or prevent the progression of diabetic nephropathy-induced renal fibrosis.

9.
Andrologia ; : e13611, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32441855

RESUMO

Benign prostate hyperplasia (BPH) is a common disease in elderly men. It has been found that the occurrence of BPH was closely related to dysregulated steroid hormones. Here, a rapid, sensitive, accurate and specific method for the quantitative profiling of five androgens in man serum was developed and validated by the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS). Using this method, dehydroepiandrosterone (DHEA), androstenedione (A4), testosterone (T), androsterone (A), dihydrotestosterone (DHT), oestrone (E1) and oestradiol (E2) were quantified in serum from man with and without BPH. BPH patients were characterised by the decreases in DHEA, A4 and T as well as increases in DHT, E2 and E1 in serum. Meanwhile, DHEA and DHT in serum were screened as sensitive biomarkers of BPH patients. This study will provide a new perspective of dysregulated steroid hormones for the diagnosis and prevention of BPH.

10.
BMC Bioinformatics ; 21(1): 183, 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32393166

RESUMO

BACKGROUND: Even though R is one of the most commonly used statistical computing environments, it lacks a graphical user interface (GUI) that appeals to students, researchers, lecturers, and practitioners in medicine and pharmacy for conducting standard data analytics. Current GUIs built on top of R, such as EZR and R-Commander, aim to facilitate R coding and visualization, but most of the functionalities are still accessed through a command-line interface (CLI). To assist practitioners of medicine and pharmacy and researchers to run most routines in fundamental statistical analysis, we developed an interactive GUI; i.e., MEPHAS, to support various web-based systems that are accessible from laptops, workstations, or tablets, under Windows, macOS (and IOS), or Linux. In addition to fundamental statistical analysis, advanced statistics such as the extended Cox regression and dimensional analyses including partial least squares regression (PLS-R) and sparse partial least squares regression (SPLS-R), are also available in MEPHAS. RESULTS: MEPHAS is a web-based GUI (https://alain003.phs.osaka-u.ac.jp/mephas/) that is based on a shiny framework. We also created the corresponding R package mephas (https://mephas.github.io/). Thus far, MEPHAS has supported four categories of statistics, including probability, hypothesis testing, regression models, and dimensional analyses. Instructions and help menus were accessible during the entire analytical process via the web-based GUI, particularly advanced dimensional data analysis that required much explanation. The GUI was designed to be intuitive for non-technical users to perform various statistical functions, e.g., managing data, customizing plots, setting parameters, and monitoring real-time results, without any R coding from users. All generated graphs can be saved to local machines, and tables can be downloaded as CSV files. CONCLUSION: MEPHAS is a free and open-source web-interactive GUI that was designed to support statistical data analyses and prediction for medical and pharmaceutical practitioners and researchers. It enables various medical and pharmaceutical statistical analyses through interactive parameter settings and dynamic visualization of the results.

11.
Artigo em Inglês | MEDLINE | ID: mdl-32383595

RESUMO

Light-modulated transparent memristors combining photoresponse and data storage are promising as multifunctional devices. Herein, a multicolor light-modulated transparent memristor based on black phosphorous (BP) is designed, fabricated, and investigated. BP is a class of emerging two-dimensional (2D) materials with a natural direct band gap and a broad light absorption. Herein, BP nanosheets (BP@PS NSs) coated with polystyrene (PS) are prepared and serve as the resistive switching (RS) layer in the ITO/BP@PS/ITO memristor, which shows >75% transmittance between 350 and 1100 nm. With the aid of PS, the BP@PS-based memristor has excellent RS characteristics such as no initial preforming, low operating voltage, and long retention time. According to the energy band model, the RS mechanism of the high and low resistance states contributes to the transformation from ohmic contact to Schottky contact. During light illumination ranging from ultraviolet (380 nm) to near infrared (785 nm), the Schottky barrier height is elevated further so that the resetting voltages and power consumption decrease. Moreover, the ON/OFF ratios are improved and the maximum enhancement is demonstrated to be more than 10 times. BP is a promising RS material in light-modulated memristors, and the novel device configuration provides insights into the development of multifunctional microelectronic devices based on 2D materials.

12.
Artigo em Inglês | MEDLINE | ID: mdl-32354181

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic aroused global public concern and became a major medical issue. This study aims to investigate the global research routine and trends of coronavirus over the last twenty years based on the production, hotspots, and frontiers of published articles as well as to provide the global health system with a bibliometric reference. The Web of Science core collection database was retrieved for coronavirus articles published from 1 January 2000 to 17 March 2020. Duplicates and discrete papers were excluded. Analysis parameters including time, regions, impact factors, and citation times were processed through professional software. A total of 9043 coronavirus articles originated from 123 countries and were published in 1202 journals. The USA contributed most articles (3101) followed by China (2230). The research was published in specialized journals including the Journal of Virology. Universities were the main institutions of science progress. High-impact articles covered fields of basic science and clinical medicine. There were two sharp increases in research yields after the severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS) outbreaks. International collaborations promoted study progress, and universities and academies act as the main force in coronavirus research. More research on prevention and treatment is needed according to an analysis of term density.


Assuntos
Infecções por Coronavirus/epidemiologia , Coronavirus , Saúde Global/tendências , Pandemias , Pneumonia Viral , Síndrome Respiratória Aguda Grave/epidemiologia , Betacoronavirus , Bibliometria , Surtos de Doenças , Humanos
13.
Genome Biol ; 21(1): 89, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32252812

RESUMO

BACKGROUND: The soil environment is responsible for sustaining most terrestrial plant life, yet we know surprisingly little about the important functions carried out by diverse microbial communities in soil. Soil microbes that inhabit the channels of decaying root systems, the detritusphere, are likely to be essential for plant growth and health, as these channels are the preferred locations of new root growth. Understanding the microbial metagenome of the detritusphere, and how it responds to agricultural management such as crop rotations and soil tillage, is vital for improving global food production. RESULTS: This study establishes an in-depth soil microbial gene catalogue based on the living-decaying rhizosphere niches in a cropping soil. The detritusphere microbiome regulates the composition and function of the rhizosphere microbiome to a greater extent than plant type: rhizosphere microbiomes of wheat and chickpea were homogenous (65-87% similarity) in the presence of decaying root (DR) systems but were heterogeneous (3-24% similarity) where DR was disrupted by tillage. When the microbiomes of the rhizosphere and the detritusphere interact in the presence of DR, there is significant degradation of plant root exudates by the rhizosphere microbiome, and genes associated with membrane transporters, carbohydrate and amino acid metabolism are enriched. CONCLUSIONS: The study describes the diversity and functional capacity of a high-quality soil microbial metagenome. The results demonstrate the contribution of the detritusphere microbiome in determining the metagenome of developing root systems. Modifications in root microbial function through soil management can ultimately govern plant health, productivity and food security.

14.
Nat Cell Biol ; 22(4): 372-379, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32231306

RESUMO

The availability of nucleotides has a direct impact on transcription. The inhibition of dihydroorotate dehydrogenase (DHODH) with leflunomide impacts nucleotide pools by reducing pyrimidine levels. Leflunomide abrogates the effective transcription elongation of genes required for neural crest development and melanoma growth in vivo1. To define the mechanism of action, we undertook an in vivo chemical suppressor screen for restoration of neural crest after leflunomide treatment. Surprisingly, we found that alterations in progesterone and progesterone receptor (Pgr) signalling strongly suppressed leflunomide-mediated neural crest effects in zebrafish. In addition, progesterone bypasses the transcriptional elongation block resulting from Paf complex deficiency, rescuing neural crest defects in ctr9 morphant and paf1(alnz24) mutant embryos. Using proteomics, we found that Pgr binds the RNA helicase protein Ddx21. ddx21-deficient zebrafish show resistance to leflunomide-induced stress. At a molecular level, nucleotide depletion reduced the chromatin occupancy of DDX21 in human A375 melanoma cells. Nucleotide supplementation reversed the gene expression signature and DDX21 occupancy changes prompted by leflunomide. Together, our results show that DDX21 acts as a sensor and mediator of transcription during nucleotide stress.


Assuntos
RNA Helicases DEAD-box/genética , Melanócitos/metabolismo , Crista Neural/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Receptores de Progesterona/genética , Proteínas de Peixe-Zebra/genética , Animais , Linhagem Celular Tumoral , RNA Helicases DEAD-box/metabolismo , Embrião não Mamífero , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Leflunomida/farmacologia , Melanócitos/efeitos dos fármacos , Melanócitos/patologia , Crista Neural/efeitos dos fármacos , Crista Neural/crescimento & desenvolvimento , Nucleotídeos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Progesterona/metabolismo , Ligação Proteica , Receptores de Progesterona/metabolismo , Transdução de Sinais , Estresse Fisiológico/genética , Elongação da Transcrição Genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/metabolismo
15.
BMC Cancer ; 20(1): 340, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32321456

RESUMO

BACKGROUND: To examine the tumor characteristics, treatments and survival outcomes of prostate cancer (PCa) patients with a prostate-specific antigen (PSA) level < 4 ng/ml. METHODS: Of 205,913 men with primary prostate adenocarcinoma in the Surveillance, Epidemiology and End Results (SEER) database (2010 to 2015), 24,054 (11.68%) patients were diagnosed with a PSA level < 4 ng/ml. Comparisons of categorical variables among different groups were performed by using the Chi square test. Multivariate Cox regression analysis was adjusted for age, ethnicity, marital status, insurance status, TNM stage, Gleason grade, treatment and survival. Kaplan-Meier survival curves were constructed for overall mortality and tested by the log-rank test. RESULTS: PCa patients with a PSA level < 4 ng/ml generally had more favorable tumor characteristics: younger, lower T stage, lower Gleason grade and lower lymph node metastasis rate. However, there were more patients in stage M1 in the group of PSA level < 4 ng/ml than that in the groups of PSA level of 4-10 ng/ml, 10-20 ng/ml and > 20 ng/ml. The multivariate Cox regression model revealed that overall mortality was associated with age, marital status, race, Gleason grade, M stage and treatment approach. CONCLUSIONS: In conclusion, PCa patients with a PSA level < 4 ng/ml have more favorable tumor characteristics at diagnosis and receive more benefit from active treatment. However, those patients with advanced TNM stage and high Gleason grade should be paid more attention in clinical application.

16.
Zhen Ci Yan Jiu ; 45(4): 339-45, 2020 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-32333543

RESUMO

Pain, especially chronic pain, can cause multiple changes including sensory-discriminative, emotional-affective, and cognitive-behavior changes and thus greatly affects patients' physical and mental health and quality of life. Therefore, multi-dimensional regulation of paralgesia, cognitive impairment, and negative emotion in patients with chronic pain has become a hot spot in recent studies. The brain regions in the limbic system are involved in the formation and expression of "pain sensation-emotion-cognition". Existing evidence suggests that acupuncture has a multi-dimensional comprehensive regulatory effect on chronic pain, and the brain regions in the limbic system also mediate the analgesic effect of acupuncture. However, further studies are still needed to explore the role and mechanism of action of these brain regions in the multi-dimensional regulation of chronic pain by acupuncture. This article reviews the research advances in the neural mechanism of the limbic system in chronic pain and the role of the limbic system in mediating acupuncture analgesia and mainly elaborates on the mechanism of action of the brain regions in the limbic system in the multi-dimensional regulation of chronic pain.

17.
Urology ; 2020 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-32335086

RESUMO

OBJECTIVE: To develop and validate a novel perineal nerve block approach for transperineal prostate biopsy. PATIENTS AND METHODS: Five adult male cadavers were dissected to delineate the superficial and deep branches of the perineal nerve. Afterwards, 90 out of 115 patients were selected and randomly assigned to receive periprostatic, periapical triangle (PAT), or branches of perineal nerve (BPN) block. The primary outcome was the maximal pain intensity associated with transperineal prostate biopsy, which was assessed by the 10-point VAS. The secondary outcomes included the number of biopsy with VAS of >=4 in each biopsy procedure, and the incidences of complications. RESULTS: On the horizontal line of the upper anal border, the locations of the superficial branch of perineal nerve on the left and right sides were 1.87±0.05 cm and 1.86±0.06 cm, respectively; and the deep branch were 2.15±0.07 cm and 2.16±0.06 cm, respectively, from the midline, and lied between the deep layer of superficial fascia and prostate capsule. The number of cases finally enrolled in data analysis in periprostatic block, PAT block, and BPN block groups were 26, 27, and 30, respectively. The maximal pain intensities were 3.4 (3.1-3.7), 3.3 (3.0-3.6), and 1.8 (1.5-2.2) in the three groups, respectively, and the numbers of biopsy with the pain intensity of >=4 were 4.0 (3.2-4.9), 4.2 (3.3-5.2), and 0.7 (0.1-1.2), respectively. There were 4, 3 and 4 cases developing hematuria, and 1, 1 and 2 burdened with urine retention after biopsy in the three groups, respectively. CONCLUSION: Collectively, BPN block is a safe, effective and repeatable local anesthesia approach for transperineal prostate biopsy.

18.
J Exp Bot ; 2020 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-32337581

RESUMO

The rice (Oryza sativa) genome encodes 37 putative ß-1,4-xylanase proteins, but none of them have been characterized at the genetic level. In this work, we report the isolation of slim stem (ss) mutants with pleiotropic defects, including dwarfism, leaf tip necrosis, and withered and rolled leaves under blazing sunlight. Map-based cloning of the ss1 mutant identified the candidate gene as OsXyn1 (LOC_03g47010), which encodes a xylanase-like protein belonging to the glycoside hydrolase 10 (GH10) family. OsXyn1 was found to be widely expressed, especially in young tissues. Subcellular localization analysis showed that OsXyn1 encodes a membrane-associated protein. Physiological analysis of ss1 and the allelic ss2 mutant revealed that water uptake was partially compromised in these mutants. Consistently, the plant cell wall of the mutants exhibited middle lamella abnormalities or deficiencies. Immunogold assays revealed an unconfined distribution of xylan in the mutant cell walls, which may have contributed to a slower rate of plant cell wall biosynthesis and delayed plant growth. Additionally, water deficiency caused ABA accumulation and triggered drought responses in the mutants. The findings that OsXyn1 is involved in plant cell wall deposition and regulates plant growth and development help shed light on the functions of the rice GH10 family.

20.
Nanotechnology ; 31(32): 325501, 2020 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-32330903

RESUMO

We present a systematic investigation on the enhancement of the quality (Q) factors for guided-mode resonance (GMR) sensors with shallow subwavelength grating structures. By introducing the coupled-mode model, a theoretical high-Q factor can be achieved by choosing the proper geometric structure. Based on this method, a GMR sensor with a Q factor up to 8000, which is an order of magnitude larger than those of typical GMR sensors with Q factors within 100 ∼ 300, was demonstrated experimentally. Besides, the approached GMR sensor achieved a bulk sensitivity of 135 nm RIU-1 with a high signal to noise ratio, which supports a detection limit of 1 ng ml-1 for bovine serum albumin detection. This high performance GMR sensor paves the way towards high-throughput industrial mass production, and shows great potential for other applications, such as optical filters, spectrometer, and bio-imaging.

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