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1.
Nano Lett ; 24(28): 8472-8480, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38950892

RESUMO

Strain can modulate bandgap and carrier mobilities in two-dimensional (2D) materials. Conventional strain-application methodologies relying on flexible/patterned/nanoindented substrates are limited by low thermal tolerance, poor tunability, and/or scalability. Here, we leverage the converse piezoelectric effect to electrically generate and control strain transfer from a piezoelectric thin film to electromechanically coupled 2D MoS2. Electrical bias polarity change across the piezo film tunes the nature of strain transferred to MoS2 from compressive (∼0.23%) to tensile (∼0.14%) as verified through Raman and photoluminescence spectroscopies and substantiated by density functional theory calculations. The device architecture, on silicon substrate, integrates an MoS2 field-effect transistor on a metal-piezoelectric-metal stack enabling strain modulation of transistor drain current (130×), on/off ratio (150×), and mobility (1.19×) with high precision, reversibility, and resolution. Large, tunable tensile (1056) and compressive (-1498) strain gauge factors, electrical strain modulation, and high thermal tolerance promise facile integration with silicon-based CMOS and micro-electromechanical systems.

2.
J Clin Nurs ; 31(7-8): 798-819, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34351652

RESUMO

BACKGROUND: Workplace violence (WPV) includes verbal abuse, physical violence, bullying or mobbing, assault and sexual harassment. The area has been well researched in the developed and high-income countries among nurses and healthcare professionals, but in the case of the low and upper-middle-income countries, there remains a paucity of comprehensive data on the prevalence of WPV and its contributing factors. AIMS: To estimate the prevalence and determinants of WPV among nurses working in the South-East Asian Region and Western Pacific Regions. DESIGN: Systematic review and Meta-analysis. METHOD: A comprehensive search was done to retrieve articles based on a PRISMA compliant protocol registered in PROSPERO: CRD 42020223605. Study selection, quality assessment and data abstraction were independently done by the team members and discrepancies addressed through mutual consensus. Random-effect meta-analysis, I2 statistics and subgroup analysis were done. RESULTS: The review included 41 studies conducted among 42,222 nurses from 13 countries. The pooled prevalence of WPV, verbal abuse, physical violence, threatening behaviour, physical assault, sexual harassment and bullying/mobbing were 58% (CI 51%-64%), 64% (CI 59%-70%), 23% (CI 14%-34%), 30(CI-11%-52%), 21% (CI 8%-38%), 12% (CI 7%-17%) and 25% (17%-33%), respectively. The various determinants of WPV included attributes related to the patient, nurses and organisation. Moreover, the impact of WPV included physical, psychological repercussions on nurses and the various measures used to manage it. CONCLUSION: Nurses encounter a high level of WPV especially verbal abuse in their workplace settings. Nursing councils and professional nursing organisations should put in their effort towards the formulation and implementation of occupational safety legislation in their respective countries through appropriate political lobbying. RELEVANCE TO CLINICAL PRACTICE: Our review highlights the emerging need to focus on the prevention of WPV among nurses working in lower, middle and upper-middle-income countries. Legislation changes and organisational commitment are vital for ensuring effective policies to combat WPV.


Assuntos
Bullying , Assédio Sexual , Violência no Trabalho , Estudos Transversais , Humanos , Prevalência , Inquéritos e Questionários , Local de Trabalho/psicologia , Violência no Trabalho/psicologia
3.
J Ethn Subst Abuse ; : 1-19, 2022 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-35404781

RESUMO

There is a wide discrepancy in the epidemiology of alcohol use disorders (AUDs) due to diverse scales and survey approaches. We estimated the prevalence of AUDs by comparing the pooled prevalence based on the alcohol use disorders identification test (AUDIT) Vs. non-AUDIT (all scales other than AUDIT). This review searched the community-based prevalence of AUDs in PubMed, Web of Science, PsycINFO, Scopus, Ovid, and Google Scholar. Articles published during the years from 2000 to 2020 were included. The methodological quality of each study was scored, and data were extracted from the published reports. Pooled prevalence was estimated, and the publication bias was evaluated. Twenty-one studies conducted in different states of India included 73997 community-based respondents, which estimated the overall prevalence of AUDs as 12.5% (95% CI: 9 to 17.3%). The pooled prevalence based on AUDIT was 12.4% (AUDIT ≥8; 95% CI: 8.8 to 17.1%) in which the magnitude of hazardous and harmful alcohol use (8.6%; 95% CI: 5.7 to 12.8%; AUDIT 8-19) was significantly higher than dependent alcohol use (2.3%; 95% CI: 1.1 to 4.8%; AUDIT ≥ 20). The pooled prevalence using the non-AUDIT tool was 14.2(95%; CI: 6-30%). Our findings further reveal that about one in twelve of the population of India have AUDs, and there is a gross variation in the patterns of alcohol use across the country. The high prevalence of AUDs suggests developing a national policy to benefit alcohol use, justifying regional variations.

4.
Nano Lett ; 20(3): 1707-1717, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32078333

RESUMO

Pn heterojunctions comprising layered van der Waals (vdW) semiconductors have been used to demonstrate current-rectifiers, photodetectors, and photovoltaic devices. However, a direct or near-direct heterointerface bandgap for enhanced photogeneration in high light-absorbing few-layer vdW materials remains unexplored. In this work, for the first time, density functional theory calculations show that the heterointerface of few-layer group-6 transition metal dichalcogenide (TMD) WSe2 with group-7 ReS2 results in a sizable (0.7 eV) near-direct type-II bandgap. The interlayer IR bandgap is confirmed through IR photodetection, and microphotoluminescence measurements demonstrate type-II alignment. Few-layer flakes exhibit ultrafast response time (5 µs), high responsivity (3 A/W), and large photocurrent-generation and responsivity-enhancement at the hetero-overlap region (10-100×). Large open-circuit voltage of 0.64 V and short-circuit current of 2.6 µA enable high output electrical power. Finally, long-term air-stability and facile single contact metal fabrication process make the multifunctional few-layer WSe2/ReS2 heterostructure diode technologically promising for next-generation optoelectronics.

6.
Arch Psychiatr Nurs ; 30(1): 62-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26804503

RESUMO

Aggressive behavior by patients with severe mental illness is a major problem needing intervention. This descriptive cross sectional study examined the perception and coping strategies of caregivers with a sample of 100 toward aggressive behavior by patients with severe mental illness in the outpatient and inpatient unit of the department of psychiatry in a tertiary care hospital. The data were collected by a semistructured interview using Revised Overt Aggression Scale-modified, Aggressive Behavior and Intervention Checklist, Ways of Coping Checklist-Hindi Adaptation and Impact of Patient Aggression on Carers Scale-Adapted. The caregivers perceived aggression in varying extent from the patients. Majority used problem-focused coping to deal with aggressive behavior. Most of the caregivers perceived insisting to take medicines and talking about patient's illness as the triggers for aggressive behavior which was managed by talking to the patient calmly, lovingly and by leaving the patient alone. The findings strongly suggest aggressive behavior as a frequent problem faced by family members of patient with severe mental illness. Nursing interventions should focus on counseling and psycho education for empowering caregivers to utilize strategies to reduce occurrence of aggressive behavior from patient and ways to effectively cope with the situation.


Assuntos
Adaptação Psicológica , Agressão/psicologia , Cuidadores/psicologia , Transtornos Mentais , Unidade Hospitalar de Psiquiatria , Índice de Gravidade de Doença , Adulto , Estudos Transversais , Família , Feminino , Humanos , Masculino , Recursos Humanos de Enfermagem/psicologia , Inquéritos e Questionários
7.
Environ Technol ; 45(10): 2067-2075, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36591897

RESUMO

In the present study, both acidic and alkaline hydrolysate of pineapple waste was utilised for the production of biohydrogen using locally isolated bacterial strains. The bacteria were isolated from different wastewater sources and were identified as Proteus mirabilis, Pseudomonas aeruginosa, Bacillus altitudinus, Bacillus subtilis, Paenibacillus alvei, and Lysinibacillus sphaericus. Experimental results showed that the highest biohydrogen yield of 836.33 ± 48.02 mL H2 was produced from alkaline hydrolysate with Bacillus altitudinis during the 96thhr of fermentation. Among the different bacterial strains, B. altitudinis showed higher H2 production. Comparatively alkaline hydrolysates exhibited a higher yield of hydrogen than acidic hydrolysates. The final pH of the experiment was found to be in acidic range. The total VFA concentration ranged between 930 ± 207.85 mg/L to 3050 ± 476.97 mg/L. Both sugar degradation and COD reduction were more than 80% in the acidic and alkaline hydrolysates while the lowest sugar degradation and COD reduction were observed for the untreated biomass. The rationale behind this study was to convert the waste biomass into energy by utilising the potential of native bacterial communities.


Assuntos
Ananas , Águas Residuárias , Fermentação , Ananas/metabolismo , Frutas/química , Frutas/metabolismo , Bactérias/metabolismo , Açúcares , Hidrogênio/análise , Hidrogênio/metabolismo
8.
Indian J Community Med ; 48(1): 12-23, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37082389

RESUMO

Across India, there have been multiple studies conducted to address the issues of the mental health of healthcare workers during the COVID-19 pandemic. The present study estimated the pooled prevalence of psychological morbidity among healthcare workers during the early phase of the COVID 19 pandemic in India. We searched the following electronic bibliographic databases: PubMed, ScienceDirect, Wiley online library, and Google scholar for studies conducted from the onset of the COVID 19 pandemic until 25 September 2021. The methodological quality of each study was scored and outcome measures with uniform cut off scores as per various screening measurements were evaluated. According to the current meta analysis, the pooled estimates of depression, anxiety, stress, and insomnia among Indian healthcare workers during the COVID 19 pandemic are 20.1% (95% CI: 15.6 to 24.6%; n = 21 studies), 25.0% (95% CI: 18.4 to 31.6%; n = 20 studies), 36% (95% CI: 23.7 to 48.2%; n = 22 studies) and 18.9% (95% CI: 9.9 to 28.0%; n = 6 studies) respectively. In subgroup analyses, low quality studies based on the JBI checklist (Score < 3/9) and studies using DASS 21 showed a higher pooled prevalence of depression and anxiety. About 20-36% of the healthcare workers in India reported having depression, anxiety, and stress during the early phase of the COVID 19 pandemic. The present study provides a comprehensive review of the overall burden of mental health problems among healthcare workers during the COVID 19 pandemic in India necessitating appropriate intervention strategies to protect these frontline groups before the memory of the pandemic crisis starts to fade.

9.
Artigo em Inglês | MEDLINE | ID: mdl-38044673

RESUMO

Two-dimensional semiconductors such as monolayer MoS2 have attracted considerable attention owing to their exceptional electronic and optical characteristics. However, their practical application has been hindered by the limited light absorption resulting from atomically thin thickness and low quantum yield. A highly effective approach to address these limitations is by integrating subwavelength plasmonic nanostructures with monolayer semiconductors. In this study, we employed electron beam lithography and nanoelectroplating techniques to develop a gold nanodisc (AuND) array plasmonic platform. Monolayer MoS2 transferred on top of the AuND array yields up to 150-fold photoluminescence enhancement compared to a gold film without normalization with respect to plasmonic hot spots. In addition, the unique protocol of nanoelectroplating helps to get flat-top cylindrical discs which enable less tear during the delicate wet transfer of monolayer MoS2. We explain our experimental findings based on electromagnetic simulations.

10.
Ann Neurosci ; 30(1): 40-53, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37313337

RESUMO

Background: The burden of stroke is increasing in India, but there is limited understanding of the distribution of reported risk factors in the Indian setting. It is vital to generate robust data on these modifiable risk factors to scale up appropriate strategies for the prevention of cerebrovascular diseases in this setting. Summary: The objective of this study is to estimate the overall proportion of life style risk factors of patients with stroke in the Indian setting. We searched PubMed and Google Scholar and relevant studies published till February 2022 were included. The risk of bias assessment was considered for the study selection criterion in the meta-analysis. The publication bias was evaluated by funnel plots and Egger's test. We identified 61 studies in the systematic review and after quality assessment, 36 studies were included for meta-analysis. Random effect model was used due to the significant inconsistency among the included studies (I2 > 97%). The mean age of the participants was 53.84±9.3 years and patients with stroke were predominantly males (64%). Hypertension (56.69%; 95% CI: - 48.45 - 64.58), obesity (36.61%; 95% CI: - 19.31 - 58.23), dyslipidemia (30.6%; 95% CI: - 22 - 40.81) and diabetes mellitus (23.8%; 95% CI: - 18.79 - 29.83) are the leading intermediate conditions associated with stroke. The Physical inactivity - 29.9% (95% CI: - 22.9 - 37.1), history of tobacco use (28.59 %; 95% CI: - 22.22 - 32.94) and alcohol use (28.15 %; 95% CI: - 20.49 - 37.33) were reported as the behavioral risk factors for stroke in this setting. Key Messages: The current meta-analysis provides robust estimates of the life style related risk-factor of stroke in India based on the observational studies conducted from 1994 to 2019. Estimating the pooled analysis of stroke risk factors is crucial to predict the imposed burden of the illness and ascertain the treatment and prevention strategies for controlling the modifiable risk factors in this setting.

11.
Indian J Occup Environ Med ; 26(3): 140-150, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36408432

RESUMO

Background: The COVID-19 pandemic has necessitated the use of personal protective equipment (PPE) among the frontline health care workers (HCWs). Even though PPE helps in preventing infection, it poses significant physical and psychological impacts at varying levels. Correspondingly, multiple independent studies have brought out the PPE-associated problems. However, there exists a lacuna on comprehensive information of global prevalence related to the same. Aim: To estimate the prevalence and risk factors of PPE among HCWs during COVID-19 across the globe. Design: Systematic review and meta-analysis. Method: The review was undertaken as per the protocol registered in PROSPERO CRD42021272216 following Preferred Reporting Items for Systematic Reviews and Meta-Analysis(PRISMA) guidelines. Two independent reviewers have undertaken the search strategy, study selection, and methodological quality assessment. Discrepancies were addressed by the third reviewer. Heterogeneity was addressed through I2 statistics and forest plots generated by open meta-software. Results: A total of 16 articles conducted across 6 different countries among 10,182 HCWs were included in the review. The pooled prevalence of skin lesions, headache, sweating, breathing difficulty, vision difficulty, thirst/dry mouth, fatigue, and communication difficulty, anxiety, fear were 57 (47-66%), 51 (37-64%), 75 (56-90%), 44 (23-68%), 61 (21-94%), 54 (30-77%), 67 (58-76%), 74 (47-94%), 28 (24-33%), 14 (10-17%), respectively. Moreover, the various risk factors included are the use of PPE for >6 h and young females. In addition, the medical management of new-onset problems created an additional burden on the frontline health care personnel (HCP). Conclusion: The frontline HCWs encountered physical and psychological problems at varying levels as a result of wearing PPE which needs to be addressed to prevent the inadequate use of PPE leading to infections.

12.
ACS Nano ; 16(3): 4578-4587, 2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35188740

RESUMO

Excellent light-matter interaction and a wide range of thickness-tunable bandgaps in layered vdW materials coupled by the facile fabrication of heterostructures have enabled several avenues for optoelectronic applications. Realization of high photoresponsivity at fast switching speeds is a critical challenge for 2D optoelectronics to enable high-performance photodetection for optical communication. Moving away from conventional type-II heterostructure pn junctions towards a WSe2/SnSe2 type-III configuration, we leverage the steep change in tunneling current along with a light-induced heterointerface band shift to achieve high negative photoresponsivity, while the fast carrier transport under tunneling results in high speed. In addition, the photocurrent can be controllably switched from positive to negative values, with ∼104× enhancement in responsivity, by engineering the band alignment from type-II to type-III using either the drain or the gate bias. This is further reinforced by electric-field dependent interlayer band structure calculations using density functional theory. The high negative responsivity of 2 × 104 A/W and fast response time of ∼1 µs coupled with a polarity-tunable photocurrent can lead to the development of next-generation multifunctional optoelectronic devices.

13.
Indian J Community Med ; 47(2): 160-165, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36034249

RESUMO

Background: There is scanty evidence regarding the magnitude of COVID-19-related psychological distress (PD) among the general population of India. Objectives: This study aimed to estimate the pooled prevalence of PD among the general public of India during the COVID-19 pandemic. Material and Methods: We conducted a meta-analysis of 21 online surveys conducted across the Indian subcontinent and published between 2020 and 2021. Results: Overall estimates of PD among the general public during the COVID-19 pandemic by the random-effects model is 33.3% (95% confidence interval: 23.8%-42.8%; n = 21 studies). The level of heterogeneity was high among the included studies (I2 = 99.67%). In subgroup analysis, it was found that the survey tool and the methodological quality had a significant effect on the overall prevalence estimates. Approximately 33% of the general public reported to have PD during the COVID-19 pandemic in India, although the overall prevalence varied based on survey tools and quality of studies. Conclusion: As the pandemic crisis seems to be ebbing across the world, the current findings are a wake-up call to devise pragmatic strategies to curtail the burden of similar pandemics and to successfully meet the challenges ahead.

14.
Ann Indian Acad Neurol ; 25(3): 376-382, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35936592

RESUMO

Background: The significant burden of stroke on the mortality rates of developing countries, including India, is well-documented in the literature. However, robust data regarding the aggregates of evidence on the quality of life (QOL) of stroke survivors is limited. Objective: To gather relevant information for policymakers on the QOL of stroke survivors based on observational studies conducted in the Indian setting. Methods: We searched PubMed, Scopus, and Google Scholar for studies conducted in the Indian setting. The methodological quality of each study was scored, and data were extracted from the published reports. The risk of bias assessment was conducted based on the JBI Critical Appraisal Checklist criteria. The relevant data regarding QOL were analyzed by a random effects model using R software. Results: 16 studies were included in the systematic review in which the majority of the studies recruited study participants in the hospital-based setting with an average duration of 3-6 months following the stroke episode. Our findings suggest that the pooled mean quality of life in the four dimensions of the World Health Organization Quality of Life instrument (WHOQOL-BREF) were ranged from 46.86 to 61.37 and the overall Stroke Specific Quality of Life scale (SS-QOL) mean score was 157.16. There was a significant inconsistency among the included studies as heterogeneity was high (I2 >97%). Conclusion: Assessment of the quality of life among stroke survivors is a crucial step to predict the illness' imposed burden and ascertain the effectiveness of the treatment. The present meta-analysis elucidates the aggregate estimates of quality of life and contributes to the research on the quality of life following a stroke in an Indian context.

15.
J Neurosci Rural Pract ; 13(4): 608-617, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36743765

RESUMO

Objective: The novel coronavirus (n COVID-19) has affected every walk of life across the world including India. Several studies have been available on the COVID-19-related anxiety and depressive symptoms in the public health context. However, there is a dearth of evidence of a meta-analysis regarding the pooled estimates of anxiety and depressive symptoms related to this pandemic based on the existing studies conducted among the general population of India. The aim of the study was to estimate the pooled prevalence of COVID-19-related anxiety and depressive symptoms among the general population in India. Material and Methods: We searched the following electronic bibliographic databases: PubMed, Ovid, Science Direct, and Wiley online library for studies conducted from the onset of the COVID-19 pandemic and until September 25, 2021. We separately analyzed the outcome measures based on the risk of bias assessment. The publication bias was evaluated by funnel plots and Egger's test. Results: We used a random-effect model due to the significant heterogeneity between the studies (Anxiety symptoms - I2 = 99.40% and Depressive symptoms - I2 = 95.3%). According to the index meta-analysis, the pooled estimates of anxiety and depressive symptoms among general population of India during COVID-19 pandemic are 23.5% (95% CI: 17.4-29.6%; n = 21 studies) and 20.2% (95% CI: 17.2-23.2%; n = 17 studies), respectively. In subgroup analyses, good-quality studies (Score ≥7/9) had a significant effect on the pooled prevalence. Conclusion: About one-fifth of the general population of India reported having anxiety and depressive symptoms during the COVID-19 pandemic. The pooled estimates varied with the methodological quality of included studies. The present study provides a comprehensive picture of the overall magnitude of anxiety and depressive symptoms due to the COVID-19 outbreak which will guide the policy makers to measure the burden of similar pandemics more judiciously in the future.

16.
Indian J Community Med ; 47(3): 321-327, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36438522

RESUMO

Background: Problematic internet use (PIU) among school going adolescents constitutes a major area of concern. However, no comprehensive reports are available to determine the magnitude of the problem. This study aimed to estimate the pooled prevalence of PIU among school going adolescents in India. Methods: We conducted a systematic review and meta analysis of 15 studies conducted in various parts of India. Results: The prevalence of moderate and severe PIU among Indian school going adolescents was 21.5% (95% CI: 17.0%-26.8%) and 2.6% (95% CI: 1.6%-4.2%) based on the Young Internet Addiction Test (Y IAT) cutoff points of 50 and 80, respectively. In subgroup analysis, it was found that the year of publication, gender, sampling method, and severity of addiction had a significant effect on the prevalence estimates. Conclusions: Currently, the use of the internet is rampant in India and our findings reflect nationally representative data on the magnitude of PIU among school going adolescents. About one fifth of school going adolescents are at risk of PIU in this setting. There is a need for further research in the reconsideration of cut off points of the Y IAT among Indian adolescents.

17.
ACS Appl Mater Interfaces ; 13(7): 9186-9194, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33555851

RESUMO

Clockwise to anticlockwise hysteresis crossover in current-voltage transfer characteristics of field-effect transistors (FETs) with graphene and MoS2 channels holds significant promise for nonvolatile memory applications. However, such crossovers have been shown to manifest only at high temperature. In this work, for the first time, we demonstrate room temperature hysteresis crossover in few-layer MoS2 FETs using a gate-drain underlap design to induce a differential response from traps near the MoS2-HfO2 channel-gate dielectric interface, also referred to as border traps, to applied gate bias. The appearance of trap-driven anticlockwise hysteresis at high gate voltages in underlap FETs can be unambiguously attributed to the presence of an underlap since transistors with and without the underlap region were fabricated on the same MoS2 channel flake. The underlap design also enables room temperature tuning of the anticlockwise hysteresis window (by 140×) as well as the crossover gate voltage (by 2.6×) with applied drain bias and underlap length. Comprehensive measurements of the transfer curves in ambient and vacuum conditions at varying sweep rates and temperatures (RT, 45 °C, and 65 °C) help segregate the quantitative contributions of adsorbates, interface traps, and bulk HfO2 traps to the clockwise and anticlockwise hysteresis.

18.
Nat Commun ; 12(1): 3336, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099709

RESUMO

Layered transition metal dichalcogenides have shown tremendous potential for photodetection due to their non-zero direct bandgaps, high light absorption coefficients and carrier mobilities, and ability to form atomically sharp and defect-free heterointerfaces. A critical and fundamental bottleneck in the realization of high performance detectors is their trap-dependent photoresponse that trades off responsivity with speed. This work demonstrates a facile method of attenuating this trade-off by nearly 2x through integration of a lateral, in-plane, electrostatically tunable p-n homojunction with a conventional WSe2 phototransistor. The tunable p-n junction allows modulation of the photocarrier population and width of the conducting channel independently from the phototransistor. Increased illumination current with the lateral p-n junction helps achieve responsivity enhancement upto 2.4x at nearly the same switching speed (14-16 µs) over a wide range of laser power (300 pW-33 nW). The added benefit of reduced dark current enhances specific detectivity (D*) by nearly 25x to yield a maximum measured flicker noise-limited D* of 1.1×1012 Jones. High responsivity of 170 A/W at 300 pW laser power along with the ability to detect sub-1 pW laser switching are demonstrated.

19.
ACS Appl Mater Interfaces ; 13(26): 30785-30796, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34180230

RESUMO

Two-dimensional MoS2 gas sensors have conventionally relied on a change in field-effect-transistor (FET) channel resistance or in the Schottky contact/pn homojunction barrier. We demonstrate an enhancement in sensitivity (6×) and dynamic response along with a reduction in detection limit (8×) and power (104×) in a gate-tunable type-II WSe2(p)/MoS2(n) heterodiode gas sensor over an MoS2 FET on the same flake. Measurements for varying NO2 concentration, gate bias, and MoS2 flake thickness, reinforced with first-principles calculations, indicate dual-mode operation due to (i) a series resistance-based exponential change in the high-bias thermionic current (high sensitivity), and (ii) a heterointerface carrier concentration-based linear change in near-zero-bias interlayer recombination current (low power) resulting in sub-100 µW/cm2 power consumption. Fast and gate-bias tunable recovery enables an all-electrical, room-temperature dynamic operation. Coupled with the sensing of trinitrotoluene (TNT) molecules down to 80 ppb, this study highlights the potential of the WSe2/MoS2 pn heterojunction as a simple, low-overhead, and versatile chemical-sensing platform.

20.
J Glob Health ; 11: 05009, 2021 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-33884193

RESUMO

BACKGROUND: Nurses represent the major proportion of frontline health care professionals delivering 24/7 services to patients with an increased vulnerability towards COVID-19 infection. Mental health issues among nurses during the COVID-19 pandemic are poorly reported across the globe. Henceforth, a systematic review and meta-analysis was performed to explore the prevalence and determinants of mental health outcomes (anxiety, stress, depression, PTSD, insomnia) among nurses across the globe due to the COVID-19. METHODS: A PRISMA compliant systematic review (PROSPERO-CRD 42020204120) was carried out to identify articles from multiple databases reporting the prevalence of mental health outcomes among nurses. Proportion random effect analysis, I2 statistic, quality assessment, and sensitivity analysis were carried out. RESULTS: Pooled data on mental health outcomes were generated from 25 cross-sectional studies: 32% anxiety (95% confidence interval (CI) = 21%-44%, n (number of studies) = 21, N (sample size) = 13 641), 40.6% stress (95% CI = 25.4%-56.8%, n = 10, N = 4204), 32% depression (95% CI = 21%-44%, n = 17, N = 12 294), 18.6% PTSD (95% CI = 4.8%-38%, n = 3, N = 638), 38.3% insomnia (95% CI = 5.8%-78.6%, n = 2, N = 261) and significant risk factors for mental ailments includes; caring for COVID-19 patients, being a female, low self-efficacy, resilience, social support and having physical symptoms (sore-throat, breathlessness, cough, lethargy, myalgia, fever). CONCLUSION: The study results highlighted a higher proportion of poor mental health outcomes namely, anxiety, stress, depression, PTSD and insomnia among nurses from different parts of the world. Poor mental health outcomes among nurses warrants the need to implement proactive psychological interventions to deter the collapse of health care systems in responding to the pandemic and in particular all possible efforts should be undertaken to mitigate the risk factors. Health care organizations should provide support to nurses with sufficient flexibility. The disaster preparedness plan envisaged by nations should have provisions to address the mental health of nurses. Greater investment in addressing the global shortage of nurses should be given priority in national health policies. Attractive salary packages should be offered to nurses to prevent their emigration from low- and middle-income countries (LMICs). REGISTRATION: PROSPERO (CRD42020204120).


Assuntos
COVID-19/enfermagem , Saúde Global/estatística & dados numéricos , Transtornos Mentais/epidemiologia , Enfermeiras e Enfermeiros/psicologia , COVID-19/epidemiologia , Humanos
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