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1.
Med Microbiol Immunol ; 212(6): 407-419, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37787822

RESUMO

Mammalian cell entry (mce) operons play a vital role in cell invasion and survival of M. tuberculosis. Of the mce genes, the function of Rv0590A is still unknown. The present study was performed to investigate the function and immunogenic properties of the protein Rv0590A. Human leukemia monocytic cell line (THP-1) derived macrophages were infected with M. tuberculosis H37Rv at 3, 6, and 24 h of infection. The maximum colony forming units (CFU) were observed at 6 h (p < 0.005), followed by 3 h after infection. M. tuberculosis H37Rv and clinical isolates representative of Delhi/CAS, EAI, Beijing, Haarlem and Euro-American-superlineage were included in the study for expression analysis of mce1A, mce2A, mce3A, mce4A, and Rv0590A genes. Maximum upregulation of all mce genes was observed at 3 h of infection. All the five clinical isolates and H37Rv upregulated Rv0590A at various time points. Macrophage infection with M. tuberculosis H37Rv-overexpressing Rv0590A gene showed higher intracellular CFU as compared to that of wild-type H37Rv. Further, purified Rv0590A protein stimulated the production of TNFα, IFNγ, and IL-10 in macrophages. Thus, Rv0590A was found to be involved in cell invasion and showed good immunological response.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Animais , Humanos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Internalização do Vírus , Mycobacterium tuberculosis/genética , Antígenos de Bactérias/genética , Mamíferos
2.
Plant J ; 116(4): 1097-1117, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37824297

RESUMO

We have developed a compendium and interactive platform, named Stress Combinations and their Interactions in Plants Database (SCIPDb; http://www.nipgr.ac.in/scipdb.php), which offers information on morpho-physio-biochemical (phenome) and molecular (transcriptome and metabolome) responses of plants to different stress combinations. SCIPDb is a plant stress informatics hub for data mining on phenome, transcriptome, trait-gene ontology, and data-driven research for advancing mechanistic understanding of combined stress biology. We analyzed global phenome data from 939 studies to delineate the effects of various stress combinations on yield in major crops and found that yield was substantially affected under abiotic-abiotic stresses. Transcriptome datasets from 36 studies hosted in SCIPDb identified novel genes, whose roles have not been earlier established in combined stress. Integretome analysis under combined drought-heat stress pinpointed carbohydrate, amino acid, and energy metabolism pathways as the crucial metabolic, proteomic, and transcriptional components in plant tolerance to combined stress. These examples illustrate the application of SCIPDb in identifying novel genes and pathways involved in combined stress tolerance. Further, we showed the application of this database in identifying novel candidate genes and pathways for combined drought and pathogen stress tolerance. To our knowledge, SCIPDb is the only publicly available platform offering combined stress-specific omics big data visualization tools, such as an interactive scrollbar, stress matrix, radial tree, global distribution map, meta-phenome analysis, search, BLAST, transcript expression pattern table, Manhattan plot, and co-expression network. These tools facilitate a better understanding of the mechanisms underlying plant responses to combined stresses.


Assuntos
Plantas , Proteômica , Plantas/genética , Transcriptoma , Estresse Fisiológico/genética , Fenótipo , Secas , Regulação da Expressão Gênica de Plantas/genética
3.
Int J Mycobacteriol ; 12(3): 248-253, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37721228

RESUMO

Background: Understanding the protein's subcellular localization and secretory nature can greatly improve the target identification for diagnostic assays and drug discovery, although their identification in laboratory experiments is a time-consuming and labor-intensive process. In order to identify proteins that could be targeted for therapeutic intervention or the development of diagnostic assays, we used a variety of computational tools to predict the subcellular localization or secretory nature of mycobacterial proline-glutamate/proline-proline-glutamate (PE/PPE) proteins. Methods: PSORTb version 3.0.3, TBpred, and Gpos-mPLoc analyses were performed on 30 selected PE/PPE protein sequences, while, SignalP 6.0, SignalP 5.0, Phobius, PSORTb version 3.0.3 and TBpred were used for signal sequence predictions. Results: Gpos-mPLoc and TBpred had the highest concordance for extracellular prediction, while PSORTb and TBpred had the highest concordance for prediction of membrane localization. The tools for predicting the secretory nature of proteins had little agreement. Conclusion: Multiple computational tools must be considered to provide an indication of the subcellular localization of PE/PPE proteins. Laboratory experiments should be used to confirm the findings of the tools.


Assuntos
Mycobacterium tuberculosis , Humanos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo , Ácido Glutâmico/metabolismo , Algoritmos , Internet , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
4.
Methods Appl Fluoresc ; 10(4)2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36195079

RESUMO

In contemporary years, hybrid lead halide perovskites nanocrystals (HPNCs) have emerged as core materials for low-cost solution-processable photovoltaic, light-emitting devices as well as in other optoelectronic fields, such as high-efficiency perovskite fluorescent quantum dots (quantum dot, QD). Although the high efficiency makes them an attractive active material, reducing the Pb-toxicity and enhancing the stability while sustaining the efficiency of the HPNCs devices is important for their successful commercialization in future. Here, we report for the first time the fabrication of excellent quality Pb-less, MAPb1-xSnxBr3(x = 0 to 0.50) perovskite NCs by one-pot ultrasonication method. Interestingly, an outstanding photoluminescence quantum yield (PLQY) of 94% and better lifetime performance than 100% Pb-based HPNCs is obtained for Pb-less HPNCs. The successful incorporation of Sn MAPb1-xSnxBr3HPNCs is confirmed by energy-dispersive x-ray (EDX) and x-ray photoelectron spectroscopy (XPS) analysis. Although the particle size for Pb-less HPNCs was different, the change in morphology and structure was minimal as confirmed by transmission electron microscopy (TEM) analysis. The optical analysis indicated bandgap tuning, which is evident by the blue shift of the band edge in absorbance spectra and photoluminescence peak after incorporating Sn2+. To the best of our knowledge, this is the highest achieved PLQY for Sn-substituted hybrid Pb-based HPNCs. The synthesis by using one pot ultrasonication method might be helpful for large-scale HPNCs production and can pave the way for future research on less-toxic and stable alternatives to Pb-based HPNCs.

5.
J Contemp Dent Pract ; 23(6): 646-651, 2022 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-36259306

RESUMO

AIM: To evaluate and compare the translucency of various commercially available zirconium oxide ceramic systems, i.e., Ceramill® Zolid Classic, Ceramill® Zi, and DD Bio ZX²71 by using a dual beam UV-visible spectrophotometer. MATERIALS AND METHODS: The present study comprised of 21 disk-shaped samples of zirconia for every group, i.e., group I-Ceramill® Zolid Classic, group II-Ceramill Zi®, and group III-DD Bio ZX²71. Furthermore, each group was split into three subgroups and every subgroup had seven samples each one of 0.7, 0.8, and 0.9 mm thickness. The samples were prepared by computer-aided design/computer-aided manufacturing (CAD/CAM) system devised by Amann Girrbach AG in accord with the steps provided by the manufacturer. The entire sample was designed having 10 mm in diameter with 0.7, 0.8, and 0.9 mm thickness for every group. The UV-visible dual beam spectrophotometer equipped with D2 lamp and W lamp was used for the measurement of absorbance and transmittance in order to assess the translucency of the fabricated zirconia samples. RESULTS: The mean value of transmittance % for Ceramill® Zi at 0.8 mm came out to be 0.849 ± 0.024, i.e., the least among all, whereas the mean value of Ceramill® Zolid Classic was 1.408 ± 0.033, being the highest for the same thickness. DD Bio ZX²71 had an intermediate value of 1.274 ± 0.012. The mean value of absorbance for Ceramill® Zi at 0.8 mm came out to be 2.086 ± 0.013, i.e., the maximum among all, whereas the mean value of Ceramill® Zolid Classic was, being the lowest for the same thickness. DD Bio ZX²71 had an intermediate value of 1.902 ± 0.004. CONCLUSION: The present study data suggest that all the materials subjected to evaluation exhibited a substantial translucency. We attempted to study few of the desirable properties, these materials should possess when used for prosthetic rehabilitation with esthetic contentment a clinical setup. There has been an ambiguous distinction that Ceramill® Zi Zirconia supersedes the Ceramill® Zolid Classic and DD Bio ZX²71. Furthermore, 0.8 mm thickness substantiates to be the most ideal among 0.7, 0.8, and 0.9 mm. CLINICAL SIGNIFICANCE: The desired outcome of the procedure becomes dependent solely on the clinician's judgment to opt for the material whose properties are most fitting as per the demands of the esthetics. While a clinician should always be ambitious, but a good clinician should also bear in mind that the success of any treatment procedure not only depends on the assortment of properties of these materials but also the host response and satisfaction evoked by these materials.


Assuntos
Porcelana Dentária , Estética Dentária , Teste de Materiais , Zircônio , Cerâmica , Desenho Assistido por Computador , Propriedades de Superfície
6.
Small ; 18(27): e2201349, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35661406

RESUMO

The notorious growth of lithium (Li) dendrites and the instability of the solid electrolyte interface (SEI) during cycling make Li metal anodes unsuitable for use in commercial Li-ion batteries. Herein, the use of simple sugar coating (α-d-glucose) is demonstrated on top of Li metal to halt the growth of Li dendrites and stabilize the SEI. The α-d-glucose layer possesses high surface and adhesive energies toward Li, which promote the homogenous stripping and plating of Li ions on top of the Li metal. Density functional theory reveals that Li-ion diffusion within the α-d-glucose layer is governed by hopping around the bare sides of the O atoms and along the apparent passages formed by the glucose molecules. Stable cycling performance is achieved when combining α-d-glucose-coated Li (G|Li) anodes with sulfur- and LiFePO4 -based cathodes in both LiTFSI (ether) and LiPF6 (carbonate) electrolyte systems. A G|Li-based symmetrical cell operates at a current density of 1 mA cm-2 and areal capacity of 1 mAh cm-2 displays a stable overpotential profile for over 9 months (7000 h) of continuous charge/discharge cycling.


Assuntos
Adesivos , Lítio , Dendritos , Eletrodos , Glucose
7.
Plant Cell Rep ; 41(5): 1319-1328, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35325291

RESUMO

KEY MESSAGE: OZF1 promotes the transcription of MRD1, which is essential for SA-mediated defense against virulent and avirulent bacterial pathogens in Arabidopsis. Salicylic acid (SA) is critical for defense against biotrophic pathogens. A trans-activator protein NPR1 plays significant roles in SA-signaling. However, evidences suggest the existence of NPR1-independent pathways for SA signaling in plants. Previously, we reported Arabidopsis OXIDATION-RELATED ZN-FINGER PROTEIN1 (OZF1) as a positive regulator of NPR1-independent SA-signaling. However, the mechanism or components of OZF1-mediated SA signaling was not known. Through the analysis of differentially expressing genes, we report the identification of MTO1-RESPONDING DOWN 1 (MRD1) as a transcriptional target of OZF1. Expressions of MRD1 and its overlapping gene in Arabidopsis genome, HEI10 increase upon pathogen inoculation in an OZF1-dependent manner. Their mutants are susceptible to both virulent and avirulent bacterial pathogens and show compromised SA-mediated immunity. Overexpression of MRD1 but not the HEI10 rescues the loss-of-resistance phenotype of the ozf1 mutant. OZF1 physically associates at the MRD1 promoter area upon pathogen inoculation. Results altogether support that MRD1 is a transcriptional target of OZF1 for promoting SA-mediated defense in Arabidopsis.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/microbiologia , Ácido Salicílico/metabolismo , Ácido Salicílico/farmacologia
8.
Tuberculosis (Edinb) ; 133: 102173, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35158296

RESUMO

In an attempt to uncover genotypic indicators for isoniazid (INH) resistance in M. tuberculosis, in addition to the canonical mutations in genes associated with INH resistance, including katG, inhA and fabG promoter; we analyzed, two INH monoresistant isolates, ASTS24/13 (INHR1) and SHR1/14 (INHR2). Targeted Sanger sequencing detected a canonical mutation at katG315 only in INHR2. Infection of THP-1 cells and exposure to antituberculosis drugs led to two-fold increase in the minimum inhibitory concentration of INH in INHR2. Whole genome sequences revealed that INHR1 and INHR2 belonged to Delhi Central Asian Strain and East African Indian lineages, respectively. The sequences were compared with INH susceptible isolates with the same lineage as the INH monoresistant strains. INHR1 had a novel unique mutation STOP420Trp in the efflux pump gene Rv0849, while INHR2 had a novel mutation Arg579Ser in efflux pump gene mmpL5. Comparison of lipid associated genes showed novel mutations in INHR1 in fadE16, fadD3 and fbpD; while INHR2 had mutations in fadE1, Rv0145, Rv1425, fadD9 and mmaA3. Both isolates also demonstrated novel mutations in cell wall associated genes. Our study highlights the importance of searching for alternate mechanisms of INH resistance that may contribute to the development of more comprehensive diagnostic tools.


Assuntos
Isoniazida , Mycobacterium tuberculosis , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Proteínas de Bactérias/genética , Catalase/genética , Farmacorresistência Bacteriana/genética , Isoniazida/farmacologia , Testes de Sensibilidade Microbiana , Mutação , Polimorfismo Genético , Sequenciamento Completo do Genoma
9.
Materials (Basel) ; 14(19)2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34640106

RESUMO

A facile solution process was employed to prepare CsPbI3 as an anode material for Li-ion batteries. Rietveld refinement of the X-ray data confirms the orthorhombic phase of CsPbI3 at room temperature. As obtained from bond valence calculations, strained bonds between Pb and I are identified within PbI6 octahedral units. Morphological study shows that the as-prepared δ-CsPbI3 forms a nanorod-like structure. The XPS analysis confirm the presence of Cs (3d, 4d), Pb (4d, 4f, 5d) and I (3p, 3d, 4d). The lithiation process involves both intercalation and conversion reactions, as confirmed by cyclic voltammetry (CV) and first-principles calculations. Impedance spectroscopy coupled with the distribution function of relaxation times identifies charge transfer processes due to Li metal foil and anode/electrolyte interfaces. An initial discharge capacity of 151 mAhg-1 is found to continuously increase to reach a maximum of ~275 mAhg-1 at 65 cycles, while it drops to ~240 mAhg-1 at 75 cycles and then slowly decreases to 235 mAhg-1 at 100 cycles. Considering the performance and structural integrity during electrochemical performance, δ-CsPbI3 is a promising material for future Li-ion battery (LIB) application.

10.
Int J Mycobacteriol ; 10(3): 293-300, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34494569

RESUMO

Background: Rapidly growing mycobacteria (RGM) are increasingly being recognized as potential pathogens. RGM, particularly Mycobacterium abscessus, Mycobacterium fortuitum, and Mycobacterium chelonae, have been observed in both pulmonary and extrapulmonary infections including cutaneous, soft-tissue, and wound infections. However, there are limited reports of these potential pathogens from skin and soft-tissue infections. Moreover, the drug susceptibility profile of RGM is largely unknown in several regions of the world. Methods: We analyzed reports on RGM isolated from skin and soft-tissue infections globally for details of RGM species and drug susceptibility profile. We also analyzed the drug susceptibility profile of four RGM isolates, obtained from skin and soft-tissue infections in our laboratory, by broth microdilution method. Results: In the reports reviewed, the most common RGM isolated from skin and soft-tissue infections were M. abscessus (184/475, 38.7%), M. fortuitum (150/475, 31.5%), M. chelonae (72/475, 15%), and M. chelonae-M. abscessus complex (46/475, 9.6%). However, drug susceptibility was tested only in 26/39 (66.6%) reports. In our own laboratory, we obtained three isolates of M. abscessus and one isolate of M. fortuitum from one case of breast abscess and three cases of postsurgical wound infections. Maximum susceptibility of M. abscessus was observed to clarithromycin, amikacin, and linezolid. The M. fortuitum isolate was susceptible to clarithromycin, amikacin, clofazimine, and linezolid. Conclusion: Paucity of information available on RGM isolated from skin and soft-tissue infections highlights the need to be aware of the pathogenic potential and the drug susceptibility profile of these organisms.


Assuntos
Infecções por Mycobacterium não Tuberculosas , Mycobacterium , Amicacina , Antibacterianos/farmacologia , Claritromicina , Humanos , Testes de Sensibilidade Microbiana , Micobactérias não Tuberculosas
11.
Biosens Bioelectron ; 178: 113033, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33517230

RESUMO

Over 27 million individuals are affected every year worldwide with central nervous system (CNS) injuries. These injuries include but are not limited to traumatic brain injury (TBI) and spinal cord injury (SCI). CNS injuries remain a significant public health concern which demands reliable tools for rapid, on-sight, on-field, and point-of-care diagnostic (POC) solutions. To address these challenges, we developed a low-cost, open-source, hand-held, portable, and POC detection technology, termed as MicroDrop (µDrop), which can simultaneously detect up to eight target biomolecules and display results in both analog and digital formats. The data acquired is stored wirelessly in a cloud server for further investigation and statistical analysis. Multiplexing capability of µDrop and immuno-biosensors detects and quantifies Cleaved-Tau Protein (C-Tau) and Neuron-Filament (NFL) proteins in the blood of TBI patients. Immuno-biosensors rapidly sense the two target proteins in less than 30 min, with µDrop and a conventional potentiostat. C-Tau and NFL were selectively detected with µDrop within the dynamic range of 10 pg/mL - 100 ng/mL and the sensitivity range of 47 µA/pg mm2 - 65 µA/pg mm2. Comparing the biosensing performance with enzyme-linked immunosorbent assays (ELISA) shows that the immuno-biosensors combined with µDrop could successfully differentiate between clinical controls and injured patients.


Assuntos
Técnicas Biossensoriais , Lesões Encefálicas Traumáticas , Biomarcadores , Lesões Encefálicas Traumáticas/diagnóstico , Humanos , Neurônios , Proteínas tau
12.
Microbiol Resour Announc ; 9(46)2020 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-33184164

RESUMO

We report the draft genome sequence of Mycobacterium simiae, a slowly growing nontuberculous mycobacterium (NTM) isolated from a mouthwash sample of a healthy person. This genome of 6,603,693 bp exhibited a 66.13% GC content and 6,391 genes with 6,257 coding sequences, 3 rRNAs, and 78 tRNAs.

13.
Int J Mycobacteriol ; 9(1): 62-70, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32474491

RESUMO

Background: Rapidly growing mycobacteria (RGM) comprise nearly half of the validated species of nontuberculous mycobacteria (NTM) and have been reported to have a higher incidence in Asia as compared to Europe and America. There is limited information on RGM infections from South Asia. Hence, the present study aimed to ascertain the incidence of pulmonary infections due to RGM in Delhi and to review the status of available information on the prevalence of RGM in South Asia, a region endemic for tuberculosis. Methods: We analyzed 933 mycobacterial isolates obtained from pulmonary samples in Delhi and performed species identification by polymerase chain reaction (PCR)-restriction analysis (restriction fragment length polymorphism) and line probe assay. Drug susceptibility testing (DST) was performed by broth microdilution method. We also reviewed reports available on pulmonary infections in South Asia, attributed to RGM. Results: Of the 933 mycobacterial isolates studied, NTM were identified in 152 (16.3%). Of these, 65/152 (42.8%) were RGM comprising Mycobacterium fortuitum (34/65; 52.3%), Mycobacterium abscessus (25/65; 38.5%), Mycobacterium chelonae (3/65; 4.61%), Mycobacterium mucogenicum (2/65; 3.1%), and Mycobacterium smegmatis (1/65; 1.5%). On applying the American Thoracic Society/Infectious Diseases Society of America guidelines, 11/25 (44%) M. abscessus, 3/3 (100%) M. chelonae, and both isolates of M. mucogenicum were found to be clinically relevant. DST revealed that maximum susceptibility of the RGM was seen to linezolid, clarithromycin, and amikacin. Conclusions: Of the RGM isolated in the present study, 16/65 (24.6%) were found to be clinically relevant. Hence, it is important to recognize these organisms as potential pathogens to identify patients with RGM disease to initiate appropriate therapy.


Assuntos
Pneumopatias/epidemiologia , Pneumopatias/microbiologia , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Micobactérias não Tuberculosas/classificação , Antibacterianos/farmacologia , Ásia/epidemiologia , Humanos , Infecções por Mycobacterium não Tuberculosas/microbiologia , Micobactérias não Tuberculosas/efeitos dos fármacos , Prevalência , Clima Tropical
14.
Trop Doct ; 50(4): 340-343, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32588764

RESUMO

Culture remains the gold standard for tuberculosis (TB) diagnosis, and the mycobacteria growth indicator tube (MGIT), endorsed by the World Health Organization (WHO), is widely used. Further identification of a positive culture is done with the help of an immunochromatography assay, which often shows faint bands that are difficult to interpret. We analysed 125 BACTEC MGIT culture positive results, of which 11/16 (68.7%) of the doubtful assays, analysed by MGIT™ TBc Identification test (TBcId), were positive for Mycobacterium tuberculosis complex (MTBC), the remaining being non-tuberculous mycobacteria as determined by an in-house duplex polymerase chain reaction and line probe assay. Guidelines on faint or doubtful bands in immunochromatography assays are important so as not to overlook true-positive cases of TB.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Cromatografia de Afinidade , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/diagnóstico , Técnicas de Tipagem Bacteriana/normas , Cromatografia de Afinidade/normas , Humanos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/imunologia , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Tuberculose/microbiologia
15.
Rep Prog Phys ; 83(8): 086502, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32575080

RESUMO

Metal halide perovskites having three-dimensional crystal structures are being applied successfully in various optoelectronic applications. To address their most challenging issues-instability and toxicity-without losing efficiency, lower-dimensional perovskites appear to be promising alternatives. Recently, two-dimensional (2D) perovskite solar cells have been developed exhibiting excellent photostability and moisture-stability, together with moderate device efficiency. This review summarizes the photophysical properties and operating mechanisms of 2D perovskites as well as recent advances in their applications in solar cell devices. Also presented is an agenda for the next-stage development of stable perovskite materials for solar cell applications, highlighting the issues of stability and toxicity that require further study to ensure commercialization.

16.
ACS Appl Mater Interfaces ; 12(29): 32649-32657, 2020 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-32568520

RESUMO

Fully inorganic perovskites based on Bi3+ and Sb3+ are emerging as alternatives that overcome the toxicity and low stability of their Pb-based perovskite counterparts. Nevertheless, the thin film fabrication of Pb-free perovskites remains a struggle, with poor morphologies and incomplete conversions greatly inhibiting device performance. In this study, we modulated the crystallization of an all-inorganic dimer phase of a Sb perovskite (d-Cs3Sb2I9) through gradual increase in the annealing temperature, accompanied by the use of Lewis bases for adduct formation. Here, the role of Lewis pairing in the crystallization of the resulting Pb-free Cs3Sb2I9 thin films has been investigated. Both, "S-donor" (thiourea) and "O-donor" [N-methylpyrrolidone (NMP)] Lewis bases are examined for their abilities to form adducts with Cs+ and Sb3+ cations. Furthermore, density functional theory has been used to estimate the binding energies of these Lewis bases with the Cs3Sb2I9 lattice. Temperature-dependent photoluminescence spectroscopy revealed the nature of the band gap of d-Cs3Sb2I9. The efficiency of the resulting perovskite solar cells was enhanced to 1.8%, with excellent stability observed, when using NMP to form the adduct film. To the best of our knowledge, this is the best solar cell efficiency for the dimer phase of the inorganic Sb-based perovskite. The effects of both S- and O-donors are studied under various environmental stresses to reveal the stability responses of the devices.

17.
ChemSusChem ; 13(14): 3686-3695, 2020 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-32314499

RESUMO

Herein, core-twisted tetrachloroperylenediimides (ClPDIs) were introduced as new efficient electron-transporting materials (ETMs) to replace the commonly used fullerene acceptor PC61 BM in inverted planar perovskite solar cells (PSCs). ClPDI showed a low-lying lowest unoccupied molecular orbital (LUMO) energy level of -3.95 eV, which was compatible with the conduction band of CH3 NH3 PbI3-x Clx (-3.90 eV). In addition, the role of the length of the alkyl side chain at the imide position of ClPDI in modulating the molecular solubility, aggregation capacity for charge-transport properties, surface hydrophobicity, and PSC performance was investigated. The device based on ClPDI-C4 (ClPDI with n-butyl side chains) as ETM achieved a maximum power conversion efficiency (PCE) of 17.3 % under standard AM 1.5G illumination, which iwas very competitive with that of the reference device employing PC61 BM/C60 (PCE=17.2 %) as ETM. Moreover, the devices with ClPDIs as ETMs exhibited better device stability than that with PC61 BM/C60 . This work highlights the great potential of ClPDI derivatives as low-cost (≈2.0 USD g-1 ) and effective ETMs to obtain efficient solution-processed inverted PSCs. This class of ClPDI derivatives is expected further promote the performance and stability of PSCs after extended investigation.

18.
ACS Appl Mater Interfaces ; 11(38): 35088-35094, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31462035

RESUMO

Hybrid lead halide perovskites continue to attract interest for use in optoelectronic devices such as solar cells and light-emitting diodes. Although challenging, the replacement of toxic lead in these systems is an active field of research. Recently, the use of trivalent metal cations (Bi3+ and Sb3+) that form defect perovskites A3B2X9 has received great attention for the development of solar cells, but their light-emissive properties have not previously been studied. Herein, an all-inorganic antimony-based two-dimensional perovskite, Cs3Sb2I9, was synthesized using the solution process. Vapor-anion-exchange method was employed to change the structural composition from Cs3Sb2I9 to Cs3Sb2Br9 or Cs3Sb2Cl9 by treating CsI/SbI3 spin-coated films with SbBr3 or SbCl3, respectively. This novel method facilitates the fabrication of Cs3Sb2Br9 or Cs3Sb2Cl9 through solution processing without the need of using poorly soluble precursors (e.g., CsCl and CsBr). We go on to demonstrate electroluminescence from a device employing Cs3Sb2I9 emitter sandwiched between ITO/PEDOT:PSS and TPBi/LiF/Al as the hole and electron injection electrodes, respectively. A visible-infrared radiance of 0.012 W·Sr-1·m-2 was measured at 6 V when Cs3Sb2I9 was the active emitter layer. These proof-of-principle devices suggest a viable path toward low-dimensional, lead-free A3B2X9 perovskite optoelectronics.

19.
Sci Rep ; 9(1): 2522, 2019 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-30792461

RESUMO

Currently, the air and water pollutions are presenting the most serious global concerns. Despite the well known tremendous efforts, it could be a promising sustainability if the black carbon (BC) soot can be utilized for the practical and sustainable applications. For this, the almost complete aqueous phase photodegradation of the three well-known organic pollutant dyes as crystal violet (CV); rhodamine B (RhB); methylene blue (MB) and their mixture (CV + RhB + MB), by using water-soluble graphene nanosheets (wsGNS) isolated from the BC soot under the influence of natural sunlight is described. The plausible mechanism behind the photocatalytic degradation of dyes and their mixture has been critically analyzed via the trapping of active species and structural analysis of photodegraded products. The impact of diverse interfering ions like Ca2+, Fe3+, SO42-, HPO42-, NO3-, and Cl- on the photodegradation efficiency of wsGNS was also investigated. Importantly, the environmental assessment of the whole process has been evaluated towards the growth of wheat plants using the treated wastewater. The initial studies for the fifteen days confirmed that growth of wheat plants was almost the same in the photodegraded wastewater as being noticed in the control sample, while in case of dyes contaminated water it showed the retarded growth. Using the natural sunlight, the overall sustainability of the presented work holds the potential for the utilization of pollutant soot in real-practical applications related to the wastewater remediation and further the practical uses of treated water.

20.
3 Biotech ; 8(8): 360, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30105185

RESUMO

Use of agro-waste for production of value added products is a good alternative for developing low-cost carriers for formulation of Trichoderma-based bio-products. It provides avenues for safe utilization of wastes, while reducing cost and environment pollution load of waste disposal. The present study was undertaken to find suitable agro-waste for economical and higher mass production of Trichoderma lixii TvR1 under solid-state fermentation, optimizing culture conditions using mathematical model and assessing effect of formulated bio-product on growth of Spinach (Spinacia oleracea). Among various agro-wastes screened, sugarcane bagasse was observed to support maximum growth (20.08 × 107 spores/g) of T. lixii TvR1 which was significantly (p ≤ 0.05) higher than the others. The Response Surface Methodology (RSM) was used to optimize culture conditions using optimal point prediction analysis which predicted that maximum spore production of T. lixii TvR1 (19.1245 × 107 spores/g) will be obtained at 30 °C and 68.87% of moisture content after 31 days of incubation. Amendment of formulated bio-product of T. lixii TvR1 in soil at concentration 15% w/w promoted biomass, photosynthetic pigments, and protein content of spinach (significant at p ≤ 0.05). After 6 weeks of sowing the shoot length, root length, and photosynthetic pigments of plants irrigated daily and on alternate days were reported to be increased by 66.97, 185.03, and 82.80%; and 56.56, 71.36, and 74.64%, respectively; over the no amendment.

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