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1.
PLoS Genet ; 19(1): e1010457, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36716349

RESUMO

The tumor suppressor BRCA1-BARD1 complex regulates many cellular processes; of critical importance to its tumor suppressor function is its role in genome integrity. Although RING E3 ubiquitin ligase activity is the only known enzymatic activity of the complex, the in vivo requirement for BRCA1-BARD1 E3 ubiquitin ligase activity has been controversial. Here we probe the role of BRCA1-BARD1 E3 ubiquitin ligase activity in vivo using C. elegans. Genetic, cell biological, and biochemical analyses of mutants defective for E3 ligase activity suggest there is both E3 ligase-dependent and independent functions of the complex in the context of DNA damage repair and meiosis. We show that E3 ligase activity is important for nuclear accumulation of the complex and specifically to concentrate at meiotic recombination sites but not at DNA damage sites in proliferating germ cells. While BRCA1 alone is capable of monoubiquitylation, BARD1 is required with BRCA1 to promote polyubiquitylation. We find that the requirement for E3 ligase activity and BARD1 in DNA damage signaling and repair can be partially alleviated by driving the nuclear accumulation and self-association of BRCA1. Our data suggest that in addition to E3 ligase activity, BRCA1 may serve a structural role for DNA damage signaling and repair while BARD1 plays an accessory role to enhance BRCA1 function.


Assuntos
Caenorhabditis elegans , Proteínas Supressoras de Tumor , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas Supressoras de Tumor/genética , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Reparo do DNA/genética , Dano ao DNA/genética , Meiose/genética , Células Germinativas/metabolismo
2.
Chemphyschem ; 25(14): e202400124, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38651214

RESUMO

The imminent generation of significant amounts of Li ion battery waste is of concern due to potential detrimental environmental impacts. However, this also poses an opportunity to recycle valuable battery materials for later use. One underexplored area is using commonly employed cathode materials such as nickel, manganese cobalt (NMC) oxide as an electrocatalyst for water splitting reactions. In this work we explore the possibility of using NMC materials of different metallic ratios (NMC 622 and 811) as oxygen evolution and hydrogen evolution catalysts under alkaline conditions. We show that both materials are excellent oxygen evolution reaction (OER) electrocatalysts but perform poorly for the hydrogen evolution reaction. NMC 622 demonstrates the better OER activity with an overpotential of only 280 mV to pass 100 mA cm-2 and a low tafel slope of 42 mV dec-1. The material can also pass high current densities of 150 mA cm-2 for 24 h while also being tolerant to extensive potential cycling indicating suitability for direct integration with renewable energy inputs. This work demonstrates that NMC cathode materials if recovered from Li ion batteries are suitable OER electrocatalysts.

3.
J Anaesthesiol Clin Pharmacol ; 39(4): 628-636, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38269173

RESUMO

Background and Aims: Health care workers (HCWs) are caught in the middle of the COVID-19 pandemic storm and are exposed to a large degree of physical and emotional stress. This study was planned to describe the stressors, stress levels, emotional responses, and coping strategies adopted by HCWs amidst this pandemic. Material and Methods: This cross-sectional, web-based survey was conducted after ethics approval, using a structured performa incorporating standardized stress (PSS-10 C), emotional responses (PANAS-10), and coping strategy (Brief COPE) scales. The snowball sampling technique was used to conduct the study and collect data. Data were analyzed using SPSS 26 version (SPSS Inc., Chicago, IL, USA) statistical software. A P value of <0.05 was considered significant. Results: Out of 402 participants (65% doctors and 35% nurses), 87% perceived moderate stress levels, and nearly half of the participants were interns, residents, and medical officers. Infection to self or family members (77.1%), survival of sick patients (75.6%), aggression by patients and relatives (70.3%), and long duty hours (67%) were some of the major stressors as reported by HCWs. The most common positive emotion felt was being alert (19.17 ± 5.57) and negative emotion perceived was being upset (15.6 ± 6.06). Many participants adopted emotion and problem-focused coping strategies such as planning and strategization (68%) and positive reframing (67.6%), whereas dysfunctional coping strategies such as venting and denial were adopted less commonly. Conclusion: Moderate stress levels perceived by HCWs are a cause for concern. Emotional responses of HCWs to stress vary; however, appropriate coping strategies including emotional and problem-focused coping strategies are the need of the hour to tackle pandemic-related stress.

4.
J Med Virol ; 94(6): 2860-2869, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34854099

RESUMO

Progressive multifocal leukoencephalopathy (PML), a demyelinating disease of the brain, caused by the John Cunningham virus (JCV) is usually seen in patients who are immunocompromised. Here, we describe a case of an immunocompetent patient diagnosed with PML and a comprehensive literature review. A 64-year-old Caucasian male presented with acute worsening of progressive neurological decline with difficulty in vision and reading. Based on history, examination, cerebrospinal fluid markers, histopathology, and magnetic resonance imaging brain at the time of presentation diagnosed the patient with PML in a setting of no immunosuppression disorder. The patient was started on Pelfilgrastim with significant systematic improvement. In our literature review, it was seen that the average age of symptom presentation was 57.5 with predominance in males. Most of the patients presented with progressive neurological deficits with symptomology ranging from mild confusion, aphasia, anxiety to sensory disturbances with numbness, hemiparesis, and hemianopsia. Out of the 21 cases, patients responded to mirtazapine and intravenous pulse methylprednisolone (IVMP). The mortality rate was close to 50% with 11 fatal cases and 10 nonfatal cases. Our case and literature review demonstrate the possibility that PML may very rarely occur in patients that are immunocompetent. Furthermore, our review showed that patients responded well to mirtazapine and IVMP. We also want to highlight that the mortality rate was lower in this review and was only compared to mortality in PML associated with immunocompromised status.


Assuntos
Vírus JC , Leucoencefalopatia Multifocal Progressiva , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Humanos , Leucoencefalopatia Multifocal Progressiva/diagnóstico por imagem , Leucoencefalopatia Multifocal Progressiva/tratamento farmacológico , Imageamento por Ressonância Magnética/efeitos adversos , Masculino , Pessoa de Meia-Idade , Mirtazapina/uso terapêutico
5.
J Med Virol ; 94(8): 4015-4022, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35451090

RESUMO

Progressive multifocal leukoencephalopathy (PML) is an increasingly common and rapidly fatal demyelinating infection of central nervous system caused by the highly prevalent John Cunningham (JC) virus in immunocompromised individuals belonging to all age groups and genders. Human immunodeficiency virus (HIV) is the most common predisposing factor among other immunodeficient conditions leading to reactivation and multiple neurological symptoms. It has varied findings on magnetic resonance imaging (MRI) and diagnosis is confirmed by positive JC virus in cerebrospinal fluid (CSF). We report 12 confirmed cases of PML from a single academic center. We comprehensively described clinical presentations, risk factors, CSF and neuroimaging findings, treatment and outcome for these cases of PML, a rare disease. The cases were almost equivalently distributed among young and old age groups and both genders. Positive JC virus on CSF was present in the majority of cases along with mild to severe reduction in lymphocyte counts. Significant MRI changes were present in all cases ranging from T2 hypertense signals to white matter lesions in various regions. Treatment with the reversion of immune-modulators, optimization of antiviral therapy (ART), plasmapheresis (PLEX), IVIG, Mirtazapine, oral steroids, and others was started as soon as the diagnosis was made in the majority of the cases. However, PML is a rapidly fatal illness and hence, survival was only seen in 4 cases in our study. The objective of this article is to highlight the importance of early diagnosis of PML with CSF findings and neuroimaging, early reversion of immunosuppressive medications, and careful monitoring and treatment of HIV cases with goals to reduce mortality, long-term morbidity, and deficits.


Assuntos
Infecções por HIV , Vírus JC , Leucoencefalopatia Multifocal Progressiva , Feminino , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Humanos , Leucoencefalopatia Multifocal Progressiva/diagnóstico por imagem , Leucoencefalopatia Multifocal Progressiva/tratamento farmacológico , Masculino , Neuroimagem/efeitos adversos , Universidades , West Virginia
6.
Am J Public Health ; 112(6): 865-870, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35420894

RESUMO

House of Ruth Maryland is a comprehensive intimate partner violence (IPV) service provider. Our academic‒practitioner partnership conducted a prospective, quasi-experimental evaluation (n = 70) of on-site transitional housing and community-based rapid rehousing to meet the safety and stability needs of individuals made homeless because of IPV. By 6-month follow-up, both IPV revictimization and housing instability significantly improved (P < .001). Housing supports through an IPV service provider advanced the dual goals of safety and housing stability for IPV survivors. Safe, affordable housing is an IPV prevention strategy. (Am J Public Health. 2022;112(6):865-870. https://doi.org/10.2105/AJPH.2022.306728).


Assuntos
Habitação , Violência por Parceiro Íntimo , Humanos , Violência por Parceiro Íntimo/prevenção & controle , Maryland , Estudos Prospectivos , Sobreviventes
7.
Australas Psychiatry ; 28(1): 11-15, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31267773

RESUMO

OBJECTIVE: To explore the extent of integration of traditional and western approaches in mental health care in Pacific Island Countries (PICs). METHOD: Examination of national mental health policies and literature review. RESULTS: Traditional healers were included as resources for mental health in four of the seven policies that we were able to access. While their role in mental health care is widely acknowledged in the literature, there are few empirical studies exploring integration. CONCLUSION: Local research on integrative mental health care is needed to guide mental health policy and service development in PICs. Any research must include the full range of formal and informal service providers as well as patients and families.


Assuntos
Prestação Integrada de Cuidados de Saúde , Medicina Tradicional , Transtornos Mentais/terapia , Serviços de Saúde Mental , Prestação Integrada de Cuidados de Saúde/métodos , Prestação Integrada de Cuidados de Saúde/organização & administração , Humanos , Medicina Tradicional/métodos , Serviços de Saúde Mental/organização & administração , Ilhas do Pacífico
8.
Breast J ; 25(3): 434-438, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30972846

RESUMO

Fine needle aspiration cytology has long been an accepted diagnostic modality in combination with physical examination and mammography to investigate breast lesions. In the present era, more proficient methods such as stereotactic mammographically guided breast biopsy is the preferred choice, however, in low resource setting, FNAC still remains the most cost effective and sampling modality to diagnose breast cancer. With the intention to evaluate the efficacy and limitations of FNAC in evaluation of breast lesions in low resource setting, we employed the Masood's cytological staging system to stratify the breast lesions and correlate them with histopathology wherever possible. All breast lesions aspirates were analyzed and classified according to the Masood's cytological scoring system and correlated with histopathological findings wherever adequate material was available. A total of 776 patients were studied of which 23 aspirates were unsatisfactory, 120 aspirates were categorized as inflammatory breast disease. Six hundred and thirty-three cases were classified according to Masood's cytological system. Nonproliferative breast diseases (Group I) encompassed maximum cases with 55% followed by carcinoma in situ and invasive cancers (Group IV) with 39% and proliferative breast disease without atypia (Group II) and with atypia (Group III) which had equal number of cases constituting 2.4% each. Cyto-histopathological correlation done in 102 cases revealed 100% concordance in group IV and 75% concordance in group III while it could not be performed in Group I and II as no histopathological specimen was available in those patients. Masood Cytological grading for breast aspirates is a reliable and an easily reproducible system which can be used to formulate appropriate treatment protocols in cases presenting with breast lesions.


Assuntos
Doenças Mamárias/patologia , Neoplasias da Mama/patologia , Citodiagnóstico/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha Fina , Criança , Cromatina/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
9.
J Stroke Cerebrovasc Dis ; 28(8): 2280-2286, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31174955

RESUMO

BACKGROUND: Early diagnosis of stroke optimizes reperfusion therapies, but behavioral measures have incomplete accuracy. Electroencephalogram (EEG) has high sensitivity for immediately detecting brain ischemia. This pilot study aimed to evaluate feasibility and utility of EEG for identifying patients with a large acute ischemic stroke during Emergency Department (ED) evaluation, as these data might be useful in the prehospital setting. METHODS: A 3-minute resting EEG was recorded using a dense-array (256-lead) system in patients with suspected acute stroke arriving at the ED of a US Comprehensive Stroke Center. RESULTS: An EEG was recorded in 24 subjects, 14 with acute cerebral ischemia (including 5 with large acute ischemic stroke) and 10 without acute cerebral ischemia. Median time from stroke onset to EEG was 6.6 hours; and from ED arrival to EEG, 1.9 hours. Delta band power (P = .004) and the alpha/delta frequency band ratio (P = .0006) each significantly distinguished patients with large acute ischemic stroke (n = 5) from all other patients with suspected stroke (n = 19), with the best diagnostic utility coming from contralesional hemisphere signals. Larger infarct volume correlated with higher EEG power in the alpha/delta frequency band ratio within both the ipsilesional (r = -0.64, P = .013) and the contralesional (r = -0.78, P = .001) hemispheres. CONCLUSIONS: Within hours of stroke onset, EEG measures (1) identify patients with large acute ischemic stroke and (2) correlate with infarct volume. These results suggest that EEG measures of brain function may be useful to improve diagnosis of large acute ischemic stroke in the ED, findings that might be useful to pre-hospital applications.


Assuntos
Isquemia Encefálica/diagnóstico , Ondas Encefálicas , Encéfalo/fisiopatologia , Eletroencefalografia , Serviço Hospitalar de Emergência , Acidente Vascular Cerebral/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , Isquemia Encefálica/fisiopatologia , Estudos de Casos e Controles , Diagnóstico Precoce , Estudos de Viabilidade , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Valor Preditivo dos Testes , Prognóstico , Reprodutibilidade dos Testes , Acidente Vascular Cerebral/fisiopatologia , Fatores de Tempo , Tomografia Computadorizada por Raios X
10.
Neuroimage ; 91: 84-90, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24473097

RESUMO

Many studies have examined brain states in an effort to predict individual differences in the capacity for learning, with overall moderate results. The present study investigated how measures of cortical network function acquired at rest using dense-array EEG (256 leads) predict subsequent acquisition of a new motor skill. Brain activity was recorded in 17 healthy young subjects during 3min of wakeful rest prior to a single motor skill training session on a digital version of the pursuit rotor task. Practice was associated with significant gains in task performance (% time on target increased from 24% to 41%, p<0.0001). Using a partial least squares regression (PLS) model, coherence with the region of the left primary motor area (M1) in resting EEG data was a strong predictor of motor skill acquisition (R(2)=0.81 in a leave-one-out cross-validation analysis), exceeding the information provided by baseline behavior and demographics. Within this PLS model, greater skill acquisition was predicted by higher connectivity between M1 and left parietal cortex, possibly reflecting greater capacity for visuomotor integration, and by lower connectivity between M1 and left frontal-premotor areas, possibly reflecting differences in motor planning strategies. EEG coherence, which reflects functional connectivity, predicts individual motor skill acquisition with a level of accuracy that is remarkably high compared to prior reports using EEG or fMRI measures.


Assuntos
Córtex Cerebral/fisiologia , Aprendizagem/fisiologia , Destreza Motora/fisiologia , Adolescente , Adulto , Análise de Variância , Ritmo beta/fisiologia , Interpretação Estatística de Dados , Eletroencefalografia , Feminino , Humanos , Análise dos Mínimos Quadrados , Masculino , Córtex Motor/fisiologia , Vias Neurais/fisiologia , Lobo Parietal/fisiologia , Valor Preditivo dos Testes , Desempenho Psicomotor/fisiologia , Adulto Jovem
11.
Curr Cardiol Rev ; 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39229989

RESUMO

Thirty percent of deaths worldwide are caused by cardiovascular disorders (CVDs). As per the WHO data, the number of fatalities due to CVDs is 17.9 million years, and it is projected to cause 22.2 million deaths by 2030. In terms of gender, women die from CVD at a rate of 51% compared to 42% for males. Most people use phytochemicals, a type of traditional medicine derived from plants, either in addition to or instead of commercially available medications to treat and prevent CVD. Phytochemicals are useful in lowering cardiovascular risks, especially for lowering blood cholesterol, lowering obesity-related factors, controlling blood sugar and the consequences of type 2 diabetes, controlling oxidative stress factors and inflammation, and preventing platelet aggregation. Medicinal plants that are widely known for treating CVD include ginseng, ginkgo biloba, ganoderma lucidum, gynostemma pentaphyllum, viridis amaranthus, etc. Plant sterol, flavonoids, polyphenols, sulphur compound and terpenoid are the active phytochemicals present in these plants. The aim of this article is to cover more and more drugs that are used for cardiovascular diseases. In this article, we will learn about the use of different herbal drugs, mechanism of action, phytochemical compounds, side effects, etc. However, more research is required to comprehend the process and particular phytochemicals found in plants that treat CVD.

12.
J Phys Chem Lett ; 15(13): 3541-3548, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38526219

RESUMO

Harvesting solar energy for different applications requires the continuous development of new semiconducting materials to exploit a broad part of the solar spectrum. In this direction, antimony selenide (Sb2Se3) has attracted a tremendous amount of attention over the past few years as a light-harvesting material for photovoltaic device applications owing to its phase stability, high absorption coefficient, earth abundance, and low toxicity. Here, we have fabricated a high-quality heterojunction of a p-type Sb2Se3 film and an n-type CdS film using the thermal evaporation technique. The photocurrent of the heterosystem was significantly higher than that of the pristine materials. This optoelectronic response was investigated using femtosecond transient absorption (TA) spectroscopy. TA study reveals the existence of an instantaneous electron transfer from Sb2Se3 to CdS, accompanied by a substantial charge separation at the heterojunction. Our study deals with the investigation of a well-designed p-n device, paving the way for the fabrication of highly efficient photovoltaic devices.

13.
Artif Intell Med ; 154: 102928, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39029377

RESUMO

BACKGROUND: Alzheimer's disease (AD) is the most prevalent cause of dementia, characterized by a steady decline in mental, behavioral, and social abilities and impairs a person's capacity for independent functioning. It is a fatal neurodegenerative disease primarily affecting older adults. OBJECTIVES: The purpose of this literature review is to investigate various AD detection techniques, datasets, input modalities, algorithms, libraries, and performance evaluation metrics used to determine which model or strategy may provide superior performance. METHOD: The initial search yielded 807 papers, but only 100 research articles were chosen after applying the inclusion-exclusion criteria. This SLR analyzed research items published between January 2019 and December 2022. The ACM, Elsevier, IEEE Xplore Digital Library, PubMed, Springer and Taylor & Francis were systematically searched. The current study considers articles that used Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), APOe4 genotype, Diffusion Tensor Imaging (DTI) and Cerebrospinal Fluid (CSF) biomarkers. The study was performed following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. CONCLUSION: According to the literature survey, most studies (n = 76) used the DL strategy. The datasets used by studies were primarily derived from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. The majority of studies (n = 73) used single-modality neuroimaging data, while the remaining used multi-modal input data. In a multi-modality approach, the combination of MRI and PET scans is commonly preferred. Also, Regarding the algorithm used, Convolution Neural Network (CNN) showed the highest accuracy, 100 %, in classifying AD vs. CN subjects whereas the SVM was the most common ML algorithm, with a maximum accuracy of 99.82 %.


Assuntos
Doença de Alzheimer , Aprendizado Profundo , Aprendizado de Máquina , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/diagnóstico , Humanos , Biomarcadores , Neuroimagem/métodos , Tomografia por Emissão de Pósitrons/métodos , Imageamento por Ressonância Magnética/métodos , Algoritmos
14.
bioRxiv ; 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38659880

RESUMO

53BP1 plays a crucial role in regulating DNA damage repair pathway choice and checkpoint signaling in somatic cells; however, its role in meiosis has remained enigmatic. In this study, we demonstrate that the Caenorhabditis elegans ortholog of 53BP1, HSR-9, associates with chromatin in both proliferating and meiotic germ cells. Notably, HSR-9 is enriched on the X chromosome pair in pachytene oogenic germ cells. HSR-9 is also present at kinetochores during both mitotic and meiotic divisions but does not appear to be essential for monitoring microtubule-kinetochore attachments or tension. Using cytological markers of different steps in recombinational repair, we found that HSR-9 influences the processing of a subset of meiotic double strand breaks into COSA-1-marked crossovers. Additionally, HSR-9 plays a role in meiotic X chromosome segregation under conditions where X chromosomes fail to pair, synapse, and recombine. Together, these results highlight that chromatin-associated HSR-9 has both conserved and unique functions in the regulation of meiotic chromosome behavior.

15.
Genetics ; 227(4)2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-38884610

RESUMO

53BP1 plays a crucial role in regulating DNA damage repair pathway choice and checkpoint signaling in somatic cells; however, its role in meiosis has remained enigmatic. In this study, we demonstrate that the Caenorhabditis elegans ortholog of 53BP1, HSR-9, associates with chromatin in both proliferating and meiotic germ cells. Notably, HSR-9 is enriched on the X chromosome pair in pachytene oogenic germ cells. HSR-9 is also present at kinetochores during both mitotic and meiotic divisions but does not appear to be essential for monitoring microtubule-kinetochore attachments or tension. Using cytological markers of different steps in recombinational repair, we found that HSR-9 influences the processing of a subset of meiotic double-stranded breaks into COSA-1-marked crossovers. Additionally, HSR-9 plays a role in meiotic X chromosome segregation under conditions where X chromosomes fail to pair, synapse, and recombine. Together, these results highlight that chromatin-associated HSR-9 has both conserved and unique functions in the regulation of meiotic chromosome behavior.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Cromatina , Segregação de Cromossomos , Células Germinativas , Meiose , Cromossomo X , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Cromatina/metabolismo , Cromatina/genética , Quebras de DNA de Cadeia Dupla , Células Germinativas/metabolismo , Reparo de DNA por Recombinação , Cromossomo X/genética
16.
J Phys Chem Lett ; : 9677-9685, 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39283702

RESUMO

Colloidal one-dimensional (1D) perovskite nanorods (NRs) and metal epitaxial heterostructures (HSs) are the promising class of new materials for efficient photovoltaic and photocatalytic applications. Besides, fundamental photophysical properties and its device applications of 1D perovskite-metal HSs are limited due to their challenging synthetic protocols and difficulties in forming epitaxial growth between covalent and ionic bonds. Herein, we have synthesized the CsPbBr3 perovskite NRs-platinum (Pt) nanoparticles (NPs) (CsPbBr3/Pt) epitaxial HS using cation exchange followed by chemical reduction methods with the orthorhombic Cs2CuBr4 NRs. Here, the tertiary ammonium ions extensively helped to form the 1D Cs2CuBr4, CsPbBr3 NRs, and CsPbBr3/Pt HSs. For CsPbBr3/Pt HSs an epitaxial relationship has been established in the (020) plane of orthorhombic CsPbBr3 with the (020) plane of cubic Pt. Further, femtosecond transient absorption (TA) spectroscopy was employed to study the charge carrier dynamics of CsPbBr3/Pt HS. Upon 420 nm photoexcitation, excitons in the conduction band of CsPbBr3 NRs dissociate by electron transfer (with an ultrafast time of 1.1 ps) to the Pt domain. In addition, charge transfer (CT) was also demonstrated in the CsPbBr3/Pt HS, which is ascribed to strong electron coupling and epitaxial growth between CsPbBr3 and Pt states. This extensive understanding of the electron transfer dynamics of CsPbBr3/Pt epitaxial HS may pave the way to designing highly efficient photovoltaic and photocatalytic applications.

17.
J Phys Chem Lett ; 15(19): 5056-5062, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38701388

RESUMO

Plasmonic semiconductors are promising candidates for developing energy conversion devices due to their tunable band gap, cost-effectiveness, and nontoxicity. Such materials exhibit remarkable capabilities for harvesting infrared photons, which constitute half of the solar energy spectrum. Herein, we have synthesized near-infrared (NIR) active CuxInyS nanocrystals and CuxInyS/CdS heterostructure nanocrystals (HNCs) to investigate plasmon-induced charge transfer dynamics on an ultrafast time scale. Employing femtosecond transient absorption spectroscopy, we demonstrate that upon exciting the HNCs with sub-band gap NIR photons (λ = 840 nm), the hot holes are generated in the valence band of plasmonic CuxInyS and transferred to the adjacent semiconductor. The decreased signal intensity and accelerated hole phonon relaxation dynamics for HNCs reveal efficient transfer of plasmon-induced hot carriers from CuxInyS to CdS under both 840 and 350 nm laser excitations, providing a pathway for enhanced carrier utilization. These findings shed light on the potential of ternary chalcogenides in plasmonic applications, highlighting efficient hot carrier extraction to adjacent semiconductors.

18.
Cureus ; 15(6): e41085, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37519575

RESUMO

INTRODUCTION: Low wages, long work hours, and stressful working conditions predominantly affect the oral and general health of industrial workers, which in turn result in their tobacco consumption. This cross-sectional study examined the prevalence of tobacco use and its associated oral lesions among textile mill workers in Bhopal, India. Oral cancer and premalignant lesions are significantly increased by smoking and chewing tobacco. The study's objective was to assess and record the prevalence of oral mucosal lesions linked to tobacco use in different age groups among Bhopal textile industry workers. METHODOLOGY: A cross-sectional study was conducted among 583 textile mill workers. Data were collected using a questionnaire and the WHO Oral Health Assessment Form 2013. IBM SPSS Statistics for Windows, Version 29 (Released 2022; IBM Corp., Armonk, New York, United States) was used for the statistical analysis. Variables were compared using the mean, percentage, and standard deviation. The chi-square test and Fisher's exact test were used to compare the distribution of gender, tobacco habits, and oral mucosal lesions in different age groups. RESULTS: Males made up 69.1% of the workforce. A clear male preference was noted (P ≤ 0.001). About 64.7% of the workers did not have any tobacco-related habits, 20.8% used smokeless tobacco, 7.9% used a smoking form of tobacco, and 6.7% used both. Older age groups, 31-45 and >46 years old, had a higher proportion of users of smokeless tobacco (P ≤ 0.001). The most commonly reported oral mucosal lesions were ulcerative conditions in 6.9%, followed by oral submucous fibrosis (OSMF), keratotic lesions, and leukoplakia in 5.0%, 4.1%, and 3.6% of the study population, respectively. Leukoplakia and OSMF were prevalent in the 31-45-year age group, while ulcerative lesions were more prevalent in the 18-30-year age group (P ≤ 0.001). CONCLUSION: Workers at textile mills were more likely to use a smokeless form of tobacco. Older age groups had higher rates of smokeless tobacco use as compared to smoking, which was more prevalent in the younger age group. Oral mucosal lesions in older age groups frequently include OSMF and leukoplakia. The main reasons for engaging in the tobacco use habit were stress and a lack of awareness. Oral hygiene was a neglected entity among workers.

19.
J Phys Chem Lett ; 14(33): 7483-7489, 2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37579185

RESUMO

The p-n heterojunctions fabricated from one-dimensional (1D) p-type tin sulfide nanorods (SnS NRs) decorated with n-type zero-dimensional (0D) cadmium sulfide quantum dots (CdS QDs) have gained significant research attention in energy storage devices. Herein, we have successfully synthesized a 1D/0D SnS@CdS heterostructure (HS) using a hot injection method. Structural and morphological studies clearly suggest that CdS QDs are uniformly anchored on the surface of SnS NRs, resulting in intimate contact between two components. The photoluminescence (PL) study revealed the transfer of photoexcited holes from CdS QDs to SnS NRs, which was further confirmed by transient absorption (TA) studies. TA measurements demonstrate the hole transfer from the valence band of CdS QDs to SnS NRs and delocalization of electrons between the conduction band of SnS NRs and CdS QDs in SnS@CdS HS, resulting in efficient charge separation across the p-n heterojunction. These findings will open up a new paradigm for improving the efficiency of optoelectronic devices.

20.
Chemosphere ; 316: 137821, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36640986

RESUMO

Electrochemical treatment of organic matter for environmental remediation necessitates the development of cheap and robust electrodes that are chemically and structurally stable. To address this challenging requirement, we demonstrate a new electrochemical approach using a simple copper electrode under cathodic conditions to electrochemically generate reactive nitrosonium ions for the degradation of different classes of synthetic organic dyes. This could be achieved in an aqueous HNO3/KNO3 electrolyte at a relatively low cathodic potential of -0.5 V RHE at room temperature. UV-visible absorption spectroscopy, Raman spectroscopy, liquid chromatography - mass spectrometry and total organic carbon measurements revealed the rapid decolorisation and mineralisation of several dye types such as triarylmethane dyes (crystal violet, cresol red), an azo dye (methyl orange) as well as a sulfur containing thiazine dye (toluidine blue). The total organic carbon content of a 50 mg L-1 methyl orange solution was found to decrease by 83% after 1 h of electrolysis. Promisingly, locally sourced river and creek water samples spiked with 50 mg L-1 methyl orange were also successfully treated for up to 6 cycles at a simple Cu electrode, demonstrating potential for the remediation of polluted waterways.


Assuntos
Nitratos , Poluentes Químicos da Água , Compostos Azo/química , Corantes/química , Carbono , Eletrodos , Poluentes Químicos da Água/química
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