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A rational design of heterojunctions with high-quality contacts is essential for efficiently separating photogenerated charge carries and boosting the solar-driven harvesting capability. Herein, we fabricated a novel heterojunction of SnO2 quantum dots-anchored CdS-CdCO3 with g-C3N4 nanosheets as a superior photocatalyst. SnO2 quantum dots (SQDs) with positively charged surfaces were tightly anchored on the negatively charged surface of CdS nanosheets (NSs). The resulting CdS@SnO2 was finally decorated with g-C3N4 NSs, and a new crystalline phase of CdS-CdCO3 was formed during the hydrothermal decoration process, g-C3N4 decorated CdS-CdCO3@SnO2 (CdS-CdCO3@SnO2@g-C3N4). The as-synthesized photocatalysts were evaluated for the degradation of methyl orange dye under solar light conditions. The CdS-CdCO3@SnO2@g-C3N4 exhibited 7.7-fold and 2.3-fold enhancements in photocatalytic activities in comparison to those of the bare CdS and CdS@SnO2 NSs, respectively. The optimal performance of CdS-CdCO3@SnO2@g-C3N4 is primarily attributed to the cascade-type conduction band alignments between 2D/0D/2D heterojunctions, which can harvest maximum solar light and effectively separate photoexcited charge carriers. This work provides a new inspiration for the rational design of 2D/0D/2D heterojunction photocatalyst for green energy generation and environmental remediation applications.
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Compostos de Cádmio , Nanocompostos , Pontos Quânticos , Compostos de Estanho , Pontos Quânticos/química , Compostos de Cádmio/química , Compostos de Estanho/química , Nanocompostos/química , Catálise , Sulfetos/química , Luz Solar , Processos Fotoquímicos , Grafite/química , Compostos Azo/química , Nitrilas/química , Compostos de Nitrogênio/químicaRESUMO
The plants of the genus Salacia L. are the storehouse of several bioactive compounds, and are involved in treating human diseases and disorders. Hitherto, a number of reports have been published on in vitro biotechnology as well as microbial involvement in the improvement of Salacia spp. The present review provides comprehensive insights into biotechnological interventions such as tissue culture for plant propagation, in vitro cultures, and endophytic microbes for up-scaling the secondary metabolites and biological potential of Salacia spp. Other biotechnological interventions such as molecular markers and bio-nanomaterials for up-grading the prospective of Salacia spp. are also considered. The in vitro biotechnology of Salacia spp. is largely focused on plant regeneration, callus culture, cell suspension culture, somatic embryogenesis, and subsequent ex vitro establishment of the in vitro-raised plantlets. The compiled information on tissue cultural strategies, involvement of endophytes, molecular markers, and nanomaterials will assist the advanced research related to in vitro manipulation, domestication, and commercial cultivation of elite clones of Salacia spp. Moreover, the genetic diversity and other molecular-marker based assessments will aid in designing conservation policies as well as support upgrading and breeding initiatives for Salacia spp. KEY POINTS: ⢠Salacia spp. plays a multifaceted role in human health and disease management. ⢠Critical and updated assessment of tissue culture, endophytic microbes, metabolites, molecular markers, and bio-nanomaterials of Salacia spp. ⢠Key shortcomings and future research directions for Salacia biotechnology.
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Salacia , Humanos , Biotecnologia , Plantas , Técnicas de Cultura de Células , EndófitosRESUMO
BACKGROUND: To evaluate the effect of metformin on the plasma levels of rifampicin, isoniazid, and pyrazinamide in patients with drug-sensitive pulmonary tuberculosis being treated with first-line antituberculosis treatment (ATT) and to assess the influence of gene polymorphisms on the metabolic pathway of metformin and plasma levels of antitubercular drugs. METHODS: Nondiabetic adults aged 18-60 years with pulmonary tuberculosis were randomized to either the standard ATT (ATT group) or ATT plus metformin (METRIF group) groups in a phase IIB clinical trial. An intensive pharmacokinetic study with blood collection at 0 hour (predosing), followed by 1, 2, 4, 6, 8, and 12 hours after dosing was conducted during the first month of treatment in a subset of 60 study participants after a minimum of 14 doses. Plasma concentrations of rifampicin, isoniazid, pyrazinamide, and metformin were measured by high-performance liquid chromatography using validated methods, and pharmacokinetic parameters and OCT1 and MATE1 gene polymorphisms were compared between the groups. RESULTS: Significant increases in the clearance of rifampicin, isoniazid, and pyrazinamide were observed in patients in the METRIF group (n = 29) compared with those in the ATT group (n = 31). The AA genotypes of the single-nucleotide polymorphism of rs2289669 (MATE1) in the METRIF group showed a significantly decreased area under the concentration-time curve to the last observation point and increased clearance of rifampicin. CONCLUSIONS: Metformin altered rifampicin and isoniazid plasma concentrations in patients receiving antituberculosis treatment for pulmonary tuberculosis with little effect on sputum conversion at the end of treatment. Studies with larger sample sizes are needed to understand host drug-drug interactions.
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We describe a case of a 30-year-old MSM recently diagnosed with HIV, immunocompromised with a purplish or brown rash all over the body for 3 to 4 months. The histopathology of the cutaneous lesions and pleural effusion aspirate confirmed the diagnosis of Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL). While KS is one of the AIDS-defining illnesses seen in immunocompromised patients having low CD4 count, PEL is a rare and distinct subset of AIDS-related lymphoma. Despite the widespread availability of HIV testing, HIV diagnosis gets delayed due to stigma among MSM. This case report emphasizes the importance of early suspicion for symptoms of HIV-associated opportunistic infections in high-risk populations like MSM. The report reiterates the need for an ambient stigma-free environment for improving HIV screening in this high-risk population.
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Coinfecção , Infecções por HIV , Linfoma de Efusão Primária , Sarcoma de Kaposi , Minorias Sexuais e de Gênero , Sífilis , Tuberculose Pulmonar , Adulto , Infecções por HIV/complicações , Homossexualidade Masculina , Humanos , Índia , Linfoma de Efusão Primária/diagnóstico , Masculino , Sarcoma de Kaposi/diagnósticoRESUMO
Background & objectives: The COVID-19 pandemic had a distinct impact on scientific research and Ethics Committees (ECs). We conducted a mixed-methods investigation to understand the issues faced and solutions identified by ECs during this pandemic in India. Methods: A quantitative online survey form (30 members) and qualitative in-depth interviews (10 members) from various ECs were conducted. Thematic content analysis for qualitative and proportion analysis for quantitative data was carried out. Results: During the online survey, an average difficulty score, which was measured using the Visual Analogue Scale, was 5.3 (SD 2.1). Pressure for expedited approvals was felt by EC members with a drastic increase in the number of submission of research projects. The scarcity of information on investigational products (IPs) and requisite consent process posed major hurdles. Ongoing non-COVID studies and post-graduate dissertations were badly hit due to the shift in attention towards COVID-related research. Non-familiarity with virtual technology and lack of face-to-face interactions were highlighted as demerits. However, a few of the EC members welcomed newer methods, being time-saving, convenient and reducing travel hassles. Site monitoring and severe adverse event-related analyses were also negatively impacted upon. Solutions included the alternate methods of consenting (virtual, abbreviated), a detailed explanation of the protocol and IPs and benefits versus risk assessment. Interpretation & conclusions: Despite various challenges posed by the COVID-19 pandemic, the ECs in India steered well through the hurdles. Moreover, adapting a hybrid mode, technical training and updating guidelines were perceived as urgent by EC members.
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COVID-19 , Humanos , COVID-19/epidemiologia , Pandemias , Comitês de Ética em Pesquisa , Membro de Comitê , Inquéritos e QuestionáriosRESUMO
This study explores the facile, template-free synthesis of S-doped g-C3N4 pinhole nanosheets (SCNPNS) with porous structure for fluorescence sensing of Ag⺠ions and visible-light photocatalysis of dyes. As-synthesized SCNPNS samples were characterized by various analytical tools such as XRD, FT-IR, TEM, BET, XPS, and UVâ»vis spectroscopy. At optimal conditions, the detection linear range for Ag⺠was found to be from 0 to 1000 nM, showing the limit of detection (LOD) of 57 nM. The SCNPNS exhibited highly sensitive and selective detection of Ag⺠due to a significant fluorescence quenching via photo-induced electron transfer through Agâºâ»SCNPNS complex. Moreover, the SCNPNS exhibited 90% degradation for cationic methylene blue (MB) dye within 180 min under visible light. The enhanced photocatalytic activity of the SCNPNS was attributed to its negative zeta potential for electrostatic interaction with cationic dyes, and the pinhole porous structure can provide more active sites which can induce faster transport of the charge carrier over the surface. Our SCNPNS is proposed as an environmental safety tool due to several advantages, such as low cost, facile preparation, selective recognition of Ag⺠ions, and efficient photocatalytic degradation of cationic dyes under visible light.
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Corantes/química , Fluorescência , Grafite/química , Luz , Nanoestruturas/química , Compostos de Nitrogênio/química , Processos Fotoquímicos , Prata/química , Catálise , Limite de Detecção , Nanoestruturas/ultraestrutura , Fotólise , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios XRESUMO
The aqueous suspension of fluorescent nanoparticles were prepared by using 9-anthradehdye derivative (AH). The nanoparticles (AHNPs) were characterized using DLS-zeta sizer and SEM techniques. The photo physical properties of nanoparticles and precursor were measured and compared using UV-absorption spectroscopy, fluorescence spectroscopy and fluorescence lifetime studies. The significant overlap between fluorescence spectrum of AHNPs and excitation spectrum of Riboflavin (RF) led us to explore Fluorescence Resonance Energy Transfer (FRET) studies between AHNPs and RF in aqueous medium. The mechanism of FRET from AHNPs to RF discussed on spectral observations, thermodynamic parameters and changes produces in fluorescence lifetime in absence and presence of different concentrations of RF to AHNPs. The limit of detection for RF (0.071 µM) is considerably low compared with reported methods. Thus, we explore AHNPs as novel nano probe for quantitative determination of RF in pharmaceutical samples based on FRET study. In addition with this, AHNPs has excellent antibacterial activity than the bulk material for two different bacteria culture viz. E. coli and Bacillus sps. Graphical Abstract 9-anthradehdye based fluorescent nanoparticles (AHNPs) explores as nano probe to detect Riboflavin (RF) in aqueous medium based on Fluorescence Resonance Energy Transfer (FRET) studies. The proposed analytical method successfully applied for quantitative determination of RF in pharmaceutical samples. In addition, with this, AHNPs has excellent antibacterial activity than the bulk material for two different bacteria culture suspension viz. E. coli and Bacillus sps.
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Antracenos/administração & dosagem , Antibacterianos/administração & dosagem , Bacillus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Corantes Fluorescentes/química , Nanopartículas/administração & dosagem , Riboflavina/análise , Antracenos/química , Antibacterianos/química , Fluorescência , Transferência Ressonante de Energia de Fluorescência , Nanopartículas/química , TermodinâmicaRESUMO
The release of industrial effluents, comprising of organic dyes, antibiotics, and heavy metals poses substantial environmental and ecological threats. Among the different approaches, the utilization of heterogeneous photocatalysis based on semiconducting metal oxides is of paramount important to removal of organic ( MB dye and TC antibiotic) and inorganic pollutants ( Cr (VI) ) in wastewater. In this work, a new approach for creating type-II heterojunction photocatalysts named xNiCo2O4/BiVO4 or BNC is suggested. The as-prepared samples were thoroughly examined by means of several sophisticated analytical tools to investigate their physicochemical properties. These composites were utilized in the decomposition of MB dye, TC drug and the reduction of Cr (VI) under visible light irradiation. According to the findings, the creation of type-II heterojunction at BiVO4-NiCo2O4 interface greatly improved charge transportation while successfully preventing electron-hole recombination. Among the various composites studied, BNC-2 demonstrated an enhanced photocatalytic activity towards degradation of MB and TC, which were found to be 91 % over a period of 150 min and 95 % within only 60 min, respectively. Moreover, the photocatalytic reduction of Cr (VI) was accomplished 96 % within just 25 min. Additionally, it is discovered that BNC-2 displayed promising photostability and recyclability with a retention of >90 % after five consecutive cycles. The enhanced photocatalytic activity of BNC-2 is evidently attributed to the expedited separation and transfer of charges, as proven by photocurrent measurement, photoluminescence and electrochemical impedance spectroscopy analyses. Hence, the current amalgamation of NiCo2O4 and BiVO4 heterojunction composite has paved novel paths towards photocatalytic removal of organic as well as inorganic contaminants.
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Bismuto , Poluentes Ambientais , Bismuto/química , Luz , Antibacterianos , Óxidos/químicaRESUMO
In the rapid development of organic light-emitting diodes (OLEDs), phosphorescent transition metal complexes have played a crucial role as the most promising candidates for next generation display and lighting applications. However, most devices are fabricated using iridium and platinum-based complexes which are expensive and available in very limited quantities, whereas using relatively abundant organometallic complexes for fabrication results mostly in inefficient performance results. To overcome these issues, we have synthesized tetra copper iodide with tetra triphenyl cage like structure (denoted as CIPh) as an emerging class of luminescent material by mechanochemical grinding followed by thermal treatment for application in white OLED. The CIPh complex exhibits considerable quantum yield and a millisecond decay lifetime. Phosphorescent OLEDs were fabricated using CIPh complex as emitter shows a remarkable performance with external quantum efficiency and current efficiency of 5.28 % and 22.76 cd/A, with a high brightness of 4200 cd m-2, respectively. White OLEDs were also fabricated with a fluorescent blue and phosphorescent red emitted with (CIPh) as green emitter and achieved an impressive CRI of 82 with an EQE of over 3 %. This is the first ever attempt at fabricating WOLEDs using organocopper complex.
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OBJECTIVES: The effectiveness of lactobacilli-containing vaginal tablets (VT) in bacterial vaginosis (BV) recurrence prevention among women infected with HIV treated with standard oral metronidazole in Pune, India was studied. METHODS: Women infected with HIV with confirmed BV diagnosis (Nugent score ≥7 and Amsel criteria >3) were enrolled in a 12-month, double-blind, randomized, placebo-controlled, phase IV study between 2018 and 2021. After a standard course of oral metronidazole for 7 days (400 mg three times a day), women were randomly assigned to either lactobacilli-containing or placebo VT arms to receive VTs for 4 months. BV recurrence was assessed after the initial cure from BV. RESULTS: Of the 464 women infected with HIV, 80 women with confirmed BV were enrolled. The retention was affected due to the COVID-19 pandemic (6-month retention rates 78%). The cure was seen in 85% and 93.5% of participants from the treatment and placebo arms, respectively, after four VT cycles. BV recurrence was seen in 41.4% and 44.8% in the treatment and placebo arm, respectively, with no significant difference in the two groups. CONCLUSION: The lactobacilli-containing VT was acceptable and safe; however, the addition of VT over standard oral metronidazole did not show any additional benefit in the prevention of BV recurrence in women infected with HIV, indicating the need for long-term randomized trials among them. Registered at Clinical Trials Registry- India, (CTRI) Number: CTRI/2018/04/013298.
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COVID-19 , Infecções por HIV , Vaginose Bacteriana , Feminino , Humanos , Vaginose Bacteriana/tratamento farmacológico , Vaginose Bacteriana/prevenção & controle , Vaginose Bacteriana/diagnóstico , Metronidazol/uso terapêutico , Lactobacillus , Cremes, Espumas e Géis Vaginais/uso terapêutico , Pandemias , Índia/epidemiologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/prevenção & controle , Resultado do Tratamento , Vagina/microbiologiaRESUMO
Background: NVX-CoV2373, a Covid-19 vaccine was developed in the USA with â¼90% efficacy. The same vaccine is manufactured in India after technology transfer (called as SII-NVX-CoV2373), was evaluated in this phase 2/3 immuno-bridging study. Methods: This was an observer-blind, randomised, phase 2/3 study in 1600 adults. In phase 2, 200 participants were randomized 3:1 to SII-NVX-CoV2373 or placebo. In phase 3, 1400 participants were randomized 3:1 to SII-NVX-CoV2373 or NVX-CoV2373 (940 safety cohort and 460 immunogenicity cohort). Two doses of study products (SII-NVX-CoV2373, NVX-CoV2373 or placebo) were given 3 weeks apart. Primary objectives were to demonstrate non-inferiority of SII-NVX-CoV2373 to NVX-CoV2373 in terms of geometric mean ELISA units (GMEU) ratio of anti-S IgG antibodies 14 days after the second dose (day 36) and to determine the incidence of causally related serious adverse events (SAEs) through 180 days after the first dose. Anti-S IgG response was assessed using an Enzyme-Linked Immunosorbent Assay (ELISA) and neutralizing antibodies (nAb) were assessed by a microneutralization assay using wild type SARS CoV-2 in participants from the immunogenicity cohort at baseline, day 22, day 36 and day 180. Cell mediated immune (CMI) response was assessed in a subset of 28 participants from immunogenicity cohort by ELISpot assay at baseline, day 36 and day 180. The total follow-up was for 6 months. Trial registration: CTRI/2021/02/031554. Findings: Total 1596 participants (200 in Phase 2 and 1396 in Phase 3) received the first dose. SII-NVX-CoV2373 was found non-inferior to NVX-CoV2373 (anti-S IgG antibodies GMEU ratio 0.91; 95% CI: 0.79, 1.06). At day 36, there was more than 58-fold rise in anti-S IgG and nAb titers compared to baseline in both the groups. On day 180 visit, these antibody titers declined to levels slightly lower than those after the first dose (13-22 fold-rise above baseline). Incidence of unsolicited and solicited AEs was similar between the SII-NVX-CoV2373 and NVX-CoV2373 groups. No adverse event of special interest (AESI) was reported. No causally related SAE was reported. Interpretation: SII-NVX-CoV2373 induced a non-inferior immune response compared to NVX-CoV2373 and has acceptable safety profile. Funding: SIIPL, Indian Council of Medical Research, Novavax.
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Monoclinic BiVO4 (m-BiVO4) has been reported as promising phase for solar light driven photocatalysis. However, in the case of morphology guided BiVO4 with different synthetic conditions maintaining the m-BiVO4 phase remains a substantial challenge for achieving an efficient photocatalyst driven by solar light. Herein, a simple hydrothermal approach was used to produce well-defined template free m-BiVO4 dendrites with distinct branches for photo catalytically removal of organic pollutant and photocurrent generation. The development of monoclinic dendrite BiVO4 was confirmed after comprehensive structural, morphological, and optical examinations. FE-SEM images of m-BiVO4 revealed transformation of spherical to dendritic morphology with distinct branches by simply changing the HNO3 to NaOH ratios from 2:1 to 2:2, which are named as BVO 2-1 and BVO 2-2, respectively. The BVO 2-2 dendrites exhibited improved activity of 98% towards methylene blue (MB) photodegradation upon simulated solar light irradiation. The BVO 2-2 dendrites photoelectrode showed an outstanding photocurrent density of 1.4245 mAcm-2 than that of the BVO 2-1 spherical photoelectrode (0.7367 mAcm-2). Enhanced photocatalytic and photoelectrochemical action, could be ascribed to the unique morphological changes provides photoactive sites, harvest more light utilization together with higher separation of e-/h+ pairs. Furthermore, photocatalytic mechanism is investigated based on scavenger trapping agent, valence band XPS, UV Visible DRS and PL study. Our findings could pave the way for the development of dendritic nanostructure photocatalysts with improved photocatalytic activity.
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Poluentes Ambientais , Vanadatos , Bismuto/química , Catálise , Dendritos , Luz , Vanadatos/químicaRESUMO
Herein, the two synthesis strategies are employed for rational design of 0D/2DAg-Ag2S-CdS heterojunctions towards photocatalytic degradation of methyl orange (MO) under simulated solar light. As the first strategy, a ternary Ag-Ag2S-CdS nanosheet (NS) heterojunction was fabricated via combined cation exchange and photo-reduction (CEPR) method (Ag-Ag2S-CdS/CEPR). The second strategy employed coprecipitation (CP) method (Ag-Ag2S-CdS/CP). Strikingly, SEM, TEM and HR-TEM images are manifested the first strategy is beneficial for retaining the original thickness (20.2 nm) of CdS NSs with a dominant formation of metallic Ag, whereas the second strategy increases the thickness (33.4 nm) of CdS NSs with a dominant formation of Ag2S. The Ag-Ag2S-CdS/CEPR exhibited 1.8-fold and 3.5-fold enhancement in photocatalytic activities as compared to those of Ag-Ag2S-CdS/CP and bare CdS NSs, respectively. This enhanced photocatalytic activity could be ascribed to fact that the first strategy produces a high-quality interface with intimate contact between the Ag-Ag2S-CdS heterojunctions, resulting in enhanced separation of photo-excited charge carriers, extended light absorption, and enriched active-sites. Furthermore, the degradation efficiency of Ag-Ag2S-CdS/CEPR was significantly reduced to â¼5% in the presence of BQ (â¢O2- scavenger), indicating that â¢O2- is the major active species that can decompose MO dye under simulated solar light.
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Poluentes Ambientais , Catálise , Luz , Fotólise , Luz SolarRESUMO
Energy storage characteristics of organic molecules continue to attract attention for supercapacitor applications, as they offer simple processing and can be employed for flexible devices. The current study utilized the ultrasonically driven exfoliation to obtain poly diketo pyrrolopyrrole-thieno thiophene (PDPT) and multiwalled carbon nanotube (CNT) composite, subsequently fabricated a PDPT donor-π-acceptor heterojunction with CNT and investigated energy storage applications. The composite was characterized using series of standard analytical techniques. Morphology indicated well alighted CNT tubes on PDPT polymer nanosheets with an effective interface, providing efficient electrochemical regions, enabling fast charge transfer between PDPT and CNT. We also investigated the PDPT-CNT composite electrochemical behavior, achieving 319.2 and 105.7F.g-1 capacitances for PDPT-CNT and PDPT at 0.5 A.g-1 current density for three electrode configurations; and 126 and 42F.g-1 for symmetric structures, respectively. Experimental results confirmed that PDPT-CNT composite electrodes achieved two fold the capacitance compared with PDPT alone. The hypothesis and synthetic approach provide an excellent candidate for conjugated polymers with carbon nanotubes and energy related devices.
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Although n-type bismuth vanadate (BiVO4) is regarded as an attractive solar-light-active photoanode, its short carrier-diffusion length, sluggish oxidation kinetics, low electronic conductivity, and high recombination rate are the major intrinsic shortcomings that limit its practical application. To this end, the rational design of a solar-light-active, metal-free BiVO4-based Z-scheme heterojunction photoanode is of great significance for achieving effective charge-separation features and maximum light utilization as well as boosting redox activity for efficient environmental treatment and photoelectrochemical water splitting. Herein, we propose a facile approach for the decoration of metal-free graphitic carbon nitride (g-C3N4) nanosheets on BiVO4 to form a Z-scheme BiVO4/g-C3N4 photoanode with boosted photoelectrochemical (PEC) water splitting and rapid photoelectrocatalytic degradation of methyl orange (MO) dye under simulated solar light. The successful preparation of the Z-scheme BiVO4/g-C3N4 photoanode was confirmed by comprehensive structural, morphological, and optical analyses. Compared with the moderate photocurrent density of bare BiVO4 (0.39 mA cm-2), the Z-scheme BiVO4/g-C3N4 photoanode yields a notable photocurrent density of 1.14 mA cm-2 at 1.23 V vs. RHE (≈3-fold higher) with the promising long-term stability of 5 h without any significant photo-corrosion. Moreover, the PEC dye-degradation studies revealed that the Z-scheme BiVO4/g-C3N4 photoanode successfully degraded MO (≈90%) in 75 min, signifying a 30% improvement over bare BiVO4. This research paves the way for rational interface engineering of solar-light-active BiVO4-based noble-metal-free Z-schemes for eco-friendly PEC water splitting and water remediation.
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The invention of cost-effective, clean, and eco-friendly energy storage technology has been capturing a lot of worldwide interest. Herein, biogenically synthesized TiO2 nanoparticles (NPs) were ultrasonically coupled with biomass-derived activated carbon (BAC) to obtain composite (denoted as TiO2@BAC). With the inspiration of nature, Mentha Aquatica leaves extract was employed for biogenic preparation of TiO2 NPs, and residual solid waste (SW) after extract was subsequently utilized for BAC. It is noteworthy that, this unique intensive method does not require any harmful or toxic chemicals and solvents, and no secondary waste is generated. TEM analysis of TiO2@BAC revealed spherical morphology of TiO2 NPs (average size â¼ 18 nm) that were accumulated on nanosheets. Raman, XRD, and XPS manifested the successful construction of TiO2@BAC. The electrochemical performance of the as-synthesized BAC, TiO2 NPs, and TiO2@BAC electrodes was tested towards supercapacitor applications. Notably, the TiO2@BAC electrode exhibited capacitance of 149 F/g at a current density of 1 A/g, which is approximately twice than that of the bare TiO2 electrode (76 F/g) along with excellent capacitance restoration of â¼99%. The TiO2@BAC electrode further revealed outstanding cyclic stability, exhibiting capacitance retention of â¼90% (at 5 A/g) after 10,000 charge/discharge cycles. Furthermore, the TiO2@BAC electrode delivered optimal specific energy density (6.96 Wh/kg) and large power density (2.07 kW/kg at 10 A/g). Moreover, the TiO2@BAC delivers an excellent restoration and retention performances of â¼100 and â¼95% (after 10,000 cycles) at 1 A/g with â¼98% coulombic efficiency in symmetric configuration (maximum cell voltage of 1.2 V).
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Mentha , Capacitância Elétrica , Eletrodos , TitânioRESUMO
Stability of the photocatalyst, maximum solar energy harvesting and effective photogenerated charge carrier separation are yet demanding key features of the photocatalysis for pollutant abetment and photo-electrochemical applications. Herein, we report the in situ solvothermal synthesis of CdS-Bi2MoO6 core-shell heterostructures (CdS-Bi2MoO6 CSHs) for the photocatalytic elimination of methyl orange (MO) under visible light. The as-synthesized CdS-Bi2MoO6 CSHs exhibited highest photocatalytic performance of 98.5%, which is approximately 10 and 4 folds higher than pristine Bi2MoO6 nanosheets (NSs) and CdS nanorods (NRs), respectively. This significantly enhanced photocatalytic performance is attributed to the core-shell heterostructure that improves the visible-light harvesting ability, facilitates efficient separation and transfer of the photogenerated charge carriers, as well as synergistic band alignment of both CdS NRs and Bi2MoO6 NSs. The CdS-Bi2MoO6 CSHs also showed efficient photocatalytic performance toward methylene blue (MB) as colored dye and tetracycline hydrochloride (TCH) as a colorless emerging contaminant. Additionally, the outcomes of transient photocurrent, electrochemical impedance, and photoluminescence study further corroborate that the construction of core-shell heterostructures with tight contact, leading to effective charge carrier separation. The hole (h+) and superoxide radical anion (â¢O2-) were determined to be the predominant active species accountable for the MO dye degradation. Furthermore, the CdS-Bi2MoO6 CSHs exhibited a satisfactory recycling efficiency over five cycles (reduced by approximately 6%), owing to the protective Bi2MoO6 NSs shell over the CdS NRs core, demonstrating their applicability in wastewater purification and photo-electrochemical applications.
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Bismuto , Molibdênio , Catálise , LuzRESUMO
An SeS2-loaded Co MOF and Au@PANI nanocomposite comprising the base matrix of the electrode was developed with electropolymerized molecularly imprinted polymer (MIP) consisting of p-aminobenzoic acid (PABA) and patulin (PT) to detect PT molecules based on the PT imprinted cavities. SeS2@Co MOF and Au@PANI were synthesized using hydrothermal synthesis and interfacial polymerization strategies, respectively. A suitable functional monomer to fabricate the MIP platform was selected using the density functional theory (DFT/M06-2X method). Higher electrochemical active surface area (0.985 cm2 which is 6.99 times higher than the bare SPE) and a lower charge transfer resistance (Rct = 27.8 Ω) at the MIP/Au@PANI/SeS2@Co MOF electrode was achieved based on the higher number of adsorptive sites and enhanced conductivity (electron transfer rate constant (ks = 3.24 × 10-3 s-1) of the sensing platform. The fabricated MIP sensor performance was studied in 10 mM PBS (pH = 6.4), where an improved detection limit (0.66 pM) for PT and a broad logarithmic linear dynamic range (0.001-100 nM) were both observed. The sensor possessed higher selectivity (Imprinting factor = 15.4 for PT), excellent reusability (%RSD of 10 cycles = 2.49%), high storage stability (6.7% lost after 35 days), and robust reproducibility (%RSD = 3.22%) The as-prepared MIP-based PT sensor was applied to detect PT in a real-time apple juice sample (10% diluted with PBS) with a recovery % ranging from 94.5 to 106.4%. The proposed sensor possesses great advantages in terms of cost-effectiveness, providing a simple detection strategy for long-term storage stability, and reversible cycle measurements.
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Técnicas Biossensoriais , Impressão Molecular , Patulina , Técnicas Eletroquímicas , Limite de Detecção , Polímeros Molecularmente Impressos , Reprodutibilidade dos TestesRESUMO
Recycling water and generation of H2 simultaneously as a green technology can be a key attraction in establishing environmental sustainability. Towards this endeavor, nanoporous SnS2 film electrodes deposited by a solution process on nickel foam demonstrate a promising electrocatalytic activity towards generation of H2 gas at cathode while the anodic reaction leads to the decomposition of urea-waste at the rate of 10 mA cm-2 in 1 M KOH with a lower cell-potential of 1.38 V vs RHE. The SnS2 electrode also demonstrates an excellent catalytic activity towards hydrogen evolution reaction in a wide pH range (0-14). In addition, the SnS2 film deposited on an FTO-substrate shows 97.56% photocatalytic-degradation of methylene-blue dye within 180 min under irradiation of visible light with a good recyclability of the photocatalyst, suggesting its high potentiality for the practical application. The demonstrated good electro- and photo-catalytic activities can be ascribed to the nanoporous structure of SnS2 film in a flower like 3D-fashion, offering availability of abundant active catalytic sites. Our results demonstrate the application of SnS2 nanoporous film as catalyst can be a significant greenery path for the removal of harmful inorganic/organic hazardous wastes from waste-water with simultaneous generation of green H2 fuel.
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We assessed the impact of pre-exposure prophylaxis (PrEP) in the context of a community-based HIV program among female sex workers (FSWs) in Kolkata, India. This was an open-label, uncontrolled demonstration trial. HIV seronegative FSWs over 18 years were eligible. Participants were administered daily tenofovir/emtricitabine (TDF-FTC) with follow-up visits at months 1, 3, 6, 9, 12, and 15. Drug adherence was monitored by self-report, and a random subset of participants underwent plasma TDF testing. 843 women were screened and 678 enrolled and started on PrEP. Seventy-nine women (11%) did not complete all scheduled visits: four women died of reasons unrelated to PrEP and 75 withdrew, for a 15-month retention rate of 89%. Self-reported daily adherence was over 70%. Among those tested for TDF, the percentage of women whose level reached ≥40 ng/mL was 65% by their final visit. There were no HIV seroconversions, and no evidence of significant changes in sexual behavior. This study demonstrated the feasibility and effectiveness of PrEP for FSWs in Kolkata, with very high levels of adherence to PrEP and no HIV seroconversions. The integration of PrEP into an existing community-based HIV prevention program ensured community support and facilitated adherence.