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1.
Phys Chem Chem Phys ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38913023

RESUMO

This work studies the effect of Nb, Mo, Re dopant, and Se vacancy in WSe2 on the electronic and optical properties of the MoS2/WSe2 bilayer heterostructure based on first-principles calculations. Our research shows that the MoS2/WSe2 bilayer heterostructure exhibits a type-II band alignment with a valence band offset (VBO) of 1.07 eV and a conduction band offset (CBO) of 1.00 eV. It also shows that different dopants or defects can considerably modulate the energy band alignment and interlayer charge transfer of the heterostructure. Owing to the orbital hybridization of the dopant atoms with other atoms and the consequent enhancement of the coupling between the two structural layers, a transition of the band alignment from type-II to type-I is realized with the Re dopant. The effect of doping and defects on the electronic properties of heterojunctions contributes to applications in high-performance optoelectronic devices.

2.
Sci Rep ; 14(1): 12324, 2024 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-38811604

RESUMO

In order to become bioactive, proteins must be translated and protected from aggregation during biosynthesis. The ribosome and molecular chaperones play a key role in this process. Ribosome-bound nascent chains (RNCs) of intrinsically disordered proteins and RNCs bearing a signal/arrest sequence are known to interact with ribosomal proteins. However, in the case of RNCs bearing foldable protein sequences, not much information is available on these interactions. Here, via a combination of chemical crosslinking and time-resolved fluorescence-anisotropy, we find that nascent chains of the foldable globin apoHmp1-140 interact with ribosomal protein L23 and have a freely-tumbling non-interacting N-terminal compact region comprising 63-94 residues. Longer RNCs (apoHmp1-189) also interact with an additional yet unidentified ribosomal protein, as well as with chaperones. Surprisingly, the apparent strength of RNC/r-protein interactions does not depend on nascent-chain sequence. Overall, foldable nascent chains establish and expand interactions with selected ribosomal proteins and chaperones, as they get longer. These data are significant because they reveal the interplay between independent conformational sampling and nascent-protein interactions with the ribosomal surface.


Assuntos
Dobramento de Proteína , Proteínas Ribossômicas , Ribossomos , Ribossomos/metabolismo , Proteínas Ribossômicas/metabolismo , Proteínas Ribossômicas/química , Ligação Proteica , Chaperonas Moleculares/metabolismo , Chaperonas Moleculares/química , Proteínas Intrinsicamente Desordenadas/metabolismo , Proteínas Intrinsicamente Desordenadas/química , Biossíntese de Proteínas , Modelos Moleculares , Conformação Proteica , Humanos
3.
Lancet Microbe ; 5(4): e335-e344, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38484748

RESUMO

BACKGROUND: The origin of novel SARS-CoV-2 spike sequences found in wastewater, without corresponding detection in clinical specimens, remains unclear. We sought to determine the origin of one such cryptic wastewater lineage by tracking and characterising its persistence and genomic evolution over time. METHODS: We first detected a cryptic lineage, WI-CL-001, in municipal wastewater in Wisconsin, USA, in January, 2022. To determine the source of WI-CL-001, we systematically sampled wastewater from targeted sub-sewershed lines and maintenance holes using compositing autosamplers. Viral concentrations in wastewater samples over time were measured by RT digital PCR. In addition to using metagenomic 12s rRNA sequencing to determine the virus's host species, we also sequenced SARS-CoV-2 spike receptor binding domains, and, where possible, whole viral genomes to identify and characterise the evolution of this lineage. FINDINGS: We traced WI-CL-001 to its source at a single commercial building. There we detected the cryptic lineage at concentrations as high as 2·7 × 109 genome copies per L. The majority of 12s rRNA sequences detected in wastewater leaving the identified source building were human. Additionally, we generated over 100 viral receptor binding domain and whole-genome sequences from wastewater samples containing the cryptic lineage collected over the 13 consecutive months this virus was detectable (January, 2022, to January, 2023). These sequences contained a combination of fixed nucleotide substitutions characteristic of Pango lineage B.1.234, which circulated in humans in Wisconsin at low levels from October, 2020, to February, 2021. Despite this, mutations in the spike gene and elsewhere resembled those subsequently found in omicron variants. INTERPRETATION: We propose that prolonged detection of WI-CL-001 in wastewater indicates persistent shedding of SARS-CoV-2 from a single human initially infected by an ancestral B.1.234 virus. The accumulation of convergent omicron-like mutations in WI-CL-001's ancestral B.1.234 genome probably reflects persistent infection and extensive within-host evolution. People who shed cryptic lineages could be an important source of highly divergent viruses that sporadically emerge and spread. FUNDING: The Rockefeller Foundation, Wisconsin Department of Health Services, Centers for Disease Control and Prevention, National Institute on Drug Abuse, and the Center for Research on Influenza Pathogenesis and Transmission.


Assuntos
COVID-19 , Águas Residuárias , Estados Unidos , Humanos , SARS-CoV-2/genética , COVID-19/epidemiologia , Centers for Disease Control and Prevention, U.S.
4.
Front Nutr ; 11: 1343772, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38425484

RESUMO

Background and aims: Maternal malnutrition is a major global public health problem that can lead to serious maternal diseases. This study aimed to analyze and predict the spatio-temporal trends in the burden of maternal disorders attributable to malnutrition, and to provide a basis for scientific improvement of maternal malnutrition and targeted prevention of maternal disorders. Methods: Data on maternal disorders attributable to malnutrition, including number of deaths, disability-adjusted life years (DALYs), population attributable fractions (PAFs), age-standardized mortality rates (ASMRs), and age-standardized DALY rates (ASDRs) were obtained from the Global Burden of Disease Study 2019 to describe their epidemiological characteristics by age, region, year, and type of disease. A log-linear regression model was used to calculate the annual percentage change (AAPC) of ASMR or ASDR to reflect their temporal trends. Bayesian age-period-cohort model was used to predict the number of deaths and mortality rates to 2035. Results: Global number of deaths and DALYs for maternal disorders attributable to malnutrition declined by 42.35 and 41.61% from 1990 to 2019, with an AAPC of -3.09 (95% CI: -3.31, -2.88) and -2.98 (95% CI: -3.20, -2.77) for ASMR and ASDR, respectively. The burden was higher among younger pregnant women (20-29 years) in low and low-middle socio-demographic index (SDI) regions, whereas it was higher among older pregnant women (30-39 years) in high SDI region. Both ASMR and ASDR showed a significant decreasing trend with increasing SDI. Maternal hemorrhage had the highest burden of all diseases. Global deaths are predicted to decline from 42,350 in 2019 to 38,461 in 2035, with the ASMR declining from 1.08 (95% UI: 0.38, 1.79) to 0.89 (95% UI: 0.47, 1.31). Conclusion: Maternal malnutrition is improving globally, but in the context of the global food crisis, attention needs to be paid to malnutrition in low SDI regions, especially among young pregnant women, and corresponding measures need to be taken to effectively reduce the burden of disease.

5.
BMC Public Health ; 24(1): 832, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38500093

RESUMO

Understanding the burden associated with occupational asbestos exposure on a global and regional scale is necessary to implement coordinated prevention and control strategies. By the GBD Study 2019, we conducted a comprehensive assessment of the non-communicable diseases burden attributable to occupational asbestos exposure. In 2019, 239,330 deaths and 4,189,000 disability-adjusted life years (DALYs) worldwide due to occupational asbestos exposure occurred. 1990-2019, deaths and DALYs attributed to occupational asbestos exposure increased by 65.65% and 43.66%, respectively. Age-standardized mortality rate (ASMR) and age-standardized DALYs rate (ASDR) decreased, with the most rapid declines in high Socio-Demographic Index (SDI) regions, with average annual percent change (AAPC) of - 1.05(95%CI: -1.2, -0.89) and -1.53(95%CI: -1.71, -1.36), respectively. Lung cancer, mesothelioma and ovarian cancer were the top three contributors to the increase in deaths and DALYs, accounting for more than 96%. AAPCs of ASMR and ASDR were positively associated with SDI. Global deaths from occupational asbestos exposure were predicted to increase and ASMR to decrease by 2035, mostly in males. Due consideration should be given to the susceptibility of the elderly, the lag of asbestos onset, and the regional differences, and constantly improve the prevention and control measures of occupational asbestos exposure and related diseases.


Assuntos
Amianto , Doenças não Transmissíveis , Exposição Ocupacional , Masculino , Humanos , Idoso , Anos de Vida Ajustados por Qualidade de Vida , Doenças não Transmissíveis/epidemiologia , Carga Global da Doença , Exposição Ocupacional/efeitos adversos , Amianto/toxicidade , Saúde Global
6.
Lancet Infect Dis ; 24(7): e453-e462, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38340735

RESUMO

SARS-CoV-2 causes persistent infections in a subset of individuals, which is a major clinical and public health problem that should be prioritised for further investigation for several reasons. First, persistent SARS-CoV-2 infection often goes unrecognised, and therefore might affect a substantial number of people, particularly immunocompromised individuals. Second, the formation of tissue reservoirs (including in non-respiratory tissues) might underlie the pathophysiology of the persistent SARS-CoV-2 infection and require new strategies for diagnosis and treatment. Finally, persistent SARS-CoV-2 replication, particularly in the setting of suboptimal immune responses, is a possible source of new, divergent virus variants that escape pre-existing immunity on the individual and population levels. Defining optimal diagnostic and treatment strategies for patients with persistent virus replication and monitoring viral evolution are therefore urgent medical and public health priorities.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/epidemiologia , Replicação Viral , Hospedeiro Imunocomprometido
7.
Heliyon ; 10(1): e23548, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38187245

RESUMO

Background: Postoperative analgesia is an essential component of enhanced recovery after surgery following abdominal surgery. Studies comparing the effectiveness of epidural analgesia with that of other analgesic modalities after liver surgery have reported inconsistent results. Consequently, the use of epidural analgesia for open hepatectomy is controversial. Objective: The present single-center retrospective study aimed to compare the efficacy and safety of patient-controlled epidural analgesia (PCEA) and patient-controlled intravenous analgesia (PCIA) in adults undergoing open hepatectomy. Methods: Patients who underwent open hepatectomy between January 2018 to December 2019 at Zhongshan Hospital, Fudan University were retrospectively analyzed. Propensity score matching was used to adjust baseline information between the PCEA and PCIA groups. The primary outcome measure was scores of the numeric rating scales (NRSs) for resting, exercise, and nocturnal pain at postoperative 24 h (postoperative day 1 [POD1]) and 48 h (POD2). The secondary outcome indicators included postoperative nausea and vomiting (PONV), hypotension, pruritus, respiratory depression, functional activity score (FAS), effective analgesic pump compression ratio, analgesic relief rate, discontinuation of the analgesic pump, reasons for discontinuation of the analgesic pump, and patient satisfaction with postoperative analgesia. Results: The NRS scores of the PCEA group on POD1 were significantly lower than those of the PCIA group (P < 0.05). On POD2, the difference between the two groups was significant only for motion NRS scores (P < 0.05). The PCIA group had significantly more patients with lower FAS functional class than the PCEA group (P < 0.001). The effective analgesic pump compression ratio and the analgesic relief rate at 2 days after the surgery were lower in the PCEA group than in the PCIA group (P < 0.001). The incidence of pump discontinuation was higher in the PCEA group than in the PCIA group on POD2 (P = 0.044). Moreover, on POD1 and POD2, the PCEA group showed a higher incidence of pruritus and hypotension than the PCIA group (P < 0.001). Both groups showed no significant difference in PONV incidence. Conclusion: In patients undergoing open hepatectomy, PCEA was more effective than PCIA in relieving moderate to severe pain on POD1. However, improving the safety and effectiveness of PCEA remains a challenge.

9.
BMC Nurs ; 22(1): 346, 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37784078

RESUMO

BACKGROUND: Exploration of the relationship between individual work immersion and perceived stress is critical for clinical nurses' effective psychological interventions and human resource management, as well as to alleviate nursing staff shortages. In order to further dissect the influencing factors of perceived stress among nursing staff, our study introduces the concepts of perfectionism and social connectedness to analyze the specific pathways that influence perceived stress in terms of an individual's intrinsic and external personality traits. This study provides relevant recommendations for the development of stress management measures for nursing staff. METHODS: This was a cross-sectional survey. 993 registered clinical nurses were included from four hospitals in Guangzhou through a convenience sampling method. Clinical nurses' work immersion, perceived stress, perfectionism, and social connectedness were investigated using questionnaires based on latent profile analysis. The relationships between variables were analyzed using t-tests, analysis of variance, Pearson's correlation analysis, latent profile analysis, and moderated mediation analysis. RESULTS: The results showed that (1) general influences on nurses' perceived stress included only child, labor relationship, labor allowance, and family support; (2) nurses' work immersion contained four subgroups: lowest (12.6%), medium-low (39.8%), medium-high (39.9%), and highest (7.7%); (3) positive and negative perfectionism played a mediating role between the association of work immersion and perceived stress; (4) social connectedness played a moderating role in the mediation model of perceived stress. CONCLUSIONS: Work immersion, perfectionism, and social connectedness have an important impact on clinical nurses' perceived stress. Nursing managers or leaders should pay attention to the differences of individual work immersion status, adopt reasonable stress management strategies, accurately identify positive perfectionist groups and strengthen the relationship between groups, so as to ensure the quality of nursing care, and reduce nursing turnover and alleviate the problem of staff shortage.

10.
Anal Chem ; 95(40): 15008-15016, 2023 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-37749789

RESUMO

Efficient tuning of the polarity of photoactive nanomaterials is of great importance in improving the performance of photoelectrochemical (PEC) sensing platforms. Herein, polarity of the Ag2S/AgInS2 heterojunction is converted by radical-induced positive feedback polydopamine (PDA) adhesion, which is further employed to develop a signal-switchable PEC biosensor. In the nanocomposites, Ag2S and AgInS2 achieve electron-hole separation, exhibiting a strong anodic PEC response. Under the irradiation of light, the Ag2S/AgInS2 heterojunction is able to produce superoxide radical and hydroxyl radical intermediate species, leading to the polymerization of dopamine (DA) and the subsequent adhesion of PDA onto the Ag2S/AgInS2 heterojunction (Ag2S/AgInS2@PDA). By constructing a new electron-transfer pathway with PDA, the polarity of the Ag2S/AgInS2 heterojunction is converted, and the PEC response changes from anodic to cathodic photocurrents. In addition, since the photoreduction activity of PDA is stronger than that of the Ag2S/AgInS2 heterojunction, more superoxide radical can be produced by Ag2S/AgInS2@PDA once PDA is generated, thereby promoting the generation of PDA. Consequently, a positive feedback mechanism is established to enhance the polarity conversion of the Ag2S/AgInS2 heterojunction and amplify the responding to DA. As a result, the bioanalytical method is capable of sensitively quantifying DA in 10 orders of magnitude with an ultralow limit of detection. Moreover, the applicability of this biosensor in real samples is identified by measuring DA in fetal bovine serum and compared with a commercial ELISA method. Overall, this work offers an alternative perspective for adjusting photogenerated carriers of nanomaterials and designing high-performance PEC biosensors.


Assuntos
Técnicas Biossensoriais , Nanocompostos , Retroalimentação , Superóxidos , Técnicas Eletroquímicas/métodos , Técnicas Biossensoriais/métodos , Limite de Detecção
11.
Front Nutr ; 10: 1202763, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37693247

RESUMO

Background: The aim of this study was to assess the global burden of disease from non-communicable chronic diseases (NCD) due to diet low in fruits from 1990 to 2019. Methods: Based on data from the Global Burden of Disease (GBD) 2019, the global burden of disease due to diet low in fruits was analyzed for each country or region, disaggregated by disease type, age, sex, and year. The number of deaths and disability-adjusted life years (DALYs), population attributable fraction (PAF), age-standardized mortality rate (ASMR) and age-standardized DALY rate (ASDR) were calculated, and the average annual percentage change (AAPC) was calculated to describe trends in ASMR and ASDR from 1990 to 2019. Results: From 1990 to 2019, the number of deaths and DALYs due to diet low in fruits increased by 31.5 and 27.4%, respectively. Among the tertiary diseases, ischemic heart disease, stroke, and diabetes and kidney disease were the top three contributors to the global increase in deaths and DALYs. However, both ASMR and ASDR showed a decreasing trend. The fastest decline in ASMR and ASDR was in stroke, with AAPC of -2.13 (95% CI: -2.22, -2.05, p < 0.05) and -0.56 (95% CI: -0.62, -0.51, p < 0.05), respectively. For GBD regions, high PAF occurred mainly in South Asia, Oceania, and sub-Saharan Africa. Age-specific PAF for stroke and ischemic heart disease death attributable to diet low in fruits was significantly negatively associated with age. Diet low in fruits related ASMR and ASDR showed an M-shaped relationship with the socio-demographic index (SDI), but with an overall decreasing trend. Conclusion: The number of deaths and DALYs due to diet low in fruits continues to increase. Therefore, early nutritional interventions should be implemented by the relevant authorities to reduce the burden of diseases caused by diet low in fruits.

12.
J Med Virol ; 95(5): e28788, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37212288

RESUMO

Diagnosis by rapid antigen tests (RATs) is useful for early initiation of antiviral treatment. Because RATs are easy to use, they can be adapted for self-testing. Several kinds of RATs approved for such use by the Japanese regulatory authority are available from drug stores and websites. Most RATs for COVID-19 are based on antibody detection of the SARS-CoV-2 N protein. Since Omicron and its subvariants have accumulated several amino acid substitutions in the N protein, such amino acid changes might affect the sensitivity of RATs. Here, we investigated the sensitivity of seven RATs available in Japan, six of which are approved for public use and one of which is approved for clinical use, for the detection of BA.5, BA.2.75, BF.7, XBB.1, and BQ.1.1, as well as the delta variant (B.1.627.2). All tested RATs detected the delta variant with a detection level between 7500 and 75 000 pfu per test, and all tested RATs showed similar sensitivity to the Omicron variant and its subvariants (BA.5, BA.2.75, BF.7, XBB.1, and BQ.1.1). Human saliva did not reduce the sensitivity of the RATs tested. Espline SARS-CoV-2 N showed the highest sensitivity followed by Inspecter KOWA SARS-CoV-2 and V Trust SARS-CoV-2 Ag. Since the RATs failed to detect low levels of infectious virus, individuals whose specimens contained less infectious virus than the detection limit would be considered negative. Therefore, it is important to note that RATs may miss individuals shedding low levels of infectious virus.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/diagnóstico , Substituição de Aminoácidos , Antivirais
13.
Chem Commun (Camb) ; 58(89): 12418-12430, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36281644

RESUMO

Photoelectrochemical (PEC) biosensing as a promising and largely developing technique has been widely applied in biological analysis in recent years because of its low background signal and high sensitivity. By utilizing suitable PEC active materials to establish a photoelectric (PE) conversion system, selective and sensitive measurements can be achieved with the help of specific biological recognition elements. PEC biosensors rely on the change of photocurrent that depends on the electron transfer process of nanomaterials. Therefore, the electron manipulation of PEC active nanomaterials is crucial for PEC sensing. In this review, from the perspective of the electron transfer manipulation of PEC active nanomaterials, we summarize the principle of PEC biosensors in three parts, i.e., generation of excited electrons in PEC active materials, introduction of specific materials for the formation of new electron transfer pathways, and separation of excited electrons in semiconductors. For each part, typical PEC biosensors are displayed and compared to reveal the superiority of different principles. In addition, current challenges of PEC biosensors are discussed, and some insight is given into the development of PEC biosensors in the future.


Assuntos
Técnicas Biossensoriais , Nanoestruturas , Técnicas Eletroquímicas/métodos , Elétrons , Técnicas Biossensoriais/métodos , Semicondutores
14.
Small ; 18(13): e2105958, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35362270

RESUMO

Shape memory polymers (SMPs) are a class of smart materials that change shape when stimulated by environmental stimuli. Different from the shape memory effect at the macro level, the introduction of micro-patterning technology into SMPs strengthens the exploration of the shape memory effect at the micro/nano level. The emergence of shape memory micro/nano patterns provides a new direction for the future development of smart polymers, and their applications in the fields of biomedicine/textile/micro-optics/adhesives show huge potential. In this review, the authors introduce the types of shape memory micro/nano patterns, summarize the preparation methods, then explore the imminent and potential applications in various fields. In the end, their shortcomings and future development direction are also proposed.


Assuntos
Polímeros , Têxteis
15.
RSC Adv ; 11(32): 19616-19622, 2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35479233

RESUMO

Reversible adhesion switching on the micron scale greatly extends the functionality of shape memory polymers. Herein, we report the first usage of polystyrene microparticles for the reversible dry adhesive of the on/off switch between bonding and debonding. The reversible dry adhesive property is attributed to the stiffness change under the varying temperature of the polystyrene microparticle, as well as its ability to lock a temporary shape and recover to its original shape. The decrease in the modulus/viscosity of polystyrene microparticles at high temperature improves the surface wetting/contact and enhances the adhesive bond by contact pressure. Then, when heating above its glass transition temperature after bonding, the adhesive recovers to its initial shape, resulting in almost a zero adhesion strength. Besides, adhesion tests reveal that the magnitude of adhesion variations depends on substrates, contact pressures, and particle sizes. Therefore, as a thermotropic-induced shape memory material, the adhesive (polystyrene microparticles) can be used to create joints and can be heated to achieve its own restoration.

16.
Microb Pathog ; 138: 103828, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31682997

RESUMO

Cucumber mosaic virus (CMV) caused huge agricultural impact on Passiflora edulis. However, the interactions between CMV and P. edulis are poorly unknown, which lead to lack of prevention and control measures. In this study, we identified the infection of CMV in P. edulis through modern small RNA sequencing (sRNA-seq) technology combined with traditional electron microscope and polymerase chain reaction (PCR) methods. We also confirmed CMV infection adversely affected or modulated the contents of phytochemicals and further injured the development of P. edulis; inversely, P. edulis modulated its resistance to CMV stress by increasing the levels of secondary metabolites and the activities of antioxidant enzymes components. This is of significant importance to understand the interaction between virus infection and plant host.


Assuntos
Cucumovirus/fisiologia , Interações Hospedeiro-Patógeno , Passiflora/química , Passiflora/virologia , Compostos Fitoquímicos/química , Doenças das Plantas/virologia , Antioxidantes/química , Antioxidantes/metabolismo , Frutas/virologia , Fenótipo , Compostos Fitoquímicos/análise , Folhas de Planta/virologia , Análise de Sequência de RNA
17.
Sci Rep ; 5: 10744, 2015 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-26021483

RESUMO

Bemisia tabaci is a serious pest of vegetables and other crops worldwide. The most damaging and predominant B. tabaci biotypes are B and Q, and both are vectors of tomato yellow leaf curl virus (TYLCV). Previous research has shown that Q outperforms B in many respects but comparative research is lacking on the ability of B and Q to transmit viruses. In the present study, we tested the hypothesis that B and Q differ in their ability to transmit TYLCV and that this difference helps explain TYLCV outbreaks. We compared the acquisition, retention, and transmission of TYLCV by B and Q females and males. We found that Q females are more efficient than Q males, B females, and B males at TYLCV acquisition and transmission. Although TYLCV acquisition and transmission tended to be greater for B females than B males, the differences were not statistically significant. Based on electrical penetration graphs determination of phloem sap ingestion parameters, females fed better than males, and Q females fed better than Q males, B females, or B males. These results are consistent with the occurrences of TYLCV outbreaks in China, which have been associated with the spread of Q rather than B.


Assuntos
Hemípteros/virologia , Insetos Vetores/virologia , Doenças das Plantas/virologia , Solanum lycopersicum/virologia , Animais , Begomovirus/patogenicidade , China , Produtos Agrícolas
18.
Opt Express ; 20(24): 26127-34, 2012 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-23187468

RESUMO

A novel fiber-optic bending sensor based upon the propagation of LP21 mode is demonstrated. The sensor, comprised of an S-bend fiber on an elastic film, measures LP21 mode specklegram rotation, which increments linearly with bending angle by the stress-optic effect. The sensor is capable of experimentally achieving a sensitivity as high as 4.13 rad/m(-1). The theoretical analysis of the sensor, which is a combination of fiber coupled-mode theory and elastic-optic theory, validates the accuracy of the sensor. The sensor is also shown to be temperature-immune, and can detect both bending direction and bending angle with a large dynamic range. Furthermore, the sensor implementation incorporates inexpensive single-mode fiber at 650 nm for few-mode operation, enabling low-loss transmission and compatibility with existing interfaces.


Assuntos
Simulação por Computador , Desenho Assistido por Computador , Tecnologia de Fibra Óptica/instrumentação , Luz , Modelos Teóricos , Espalhamento de Radiação , Estresse Mecânico , Elasticidade , Desenho de Equipamento , Humanos , Refratometria/instrumentação , Resistência à Tração
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