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1.
Mol Cell ; 74(6): 1148-1163.e7, 2019 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-31005419

RESUMO

Self-renewal and pluripotency of the embryonic stem cell (ESC) state are established and maintained by multiple regulatory networks that comprise transcription factors and epigenetic regulators. While much has been learned regarding transcription factors, the function of epigenetic regulators in these networks is less well defined. We conducted a CRISPR-Cas9-mediated loss-of-function genetic screen that identified two epigenetic regulators, TAF5L and TAF6L, components or co-activators of the GNAT-HAT complexes for the mouse ESC (mESC) state. Detailed molecular studies demonstrate that TAF5L/TAF6L transcriptionally activate c-Myc and Oct4 and their corresponding MYC and CORE regulatory networks. Besides, TAF5L/TAF6L predominantly regulate their target genes through H3K9ac deposition and c-MYC recruitment that eventually activate the MYC regulatory network for self-renewal of mESCs. Thus, our findings uncover a role of TAF5L/TAF6L in directing the MYC regulatory network that orchestrates gene expression programs to control self-renewal for the maintenance of mESC state.


Assuntos
Células-Tronco Embrionárias/metabolismo , Redes Reguladoras de Genes , Células-Tronco Pluripotentes Induzidas/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Fatores Associados à Proteína de Ligação a TATA/genética , Animais , Sistemas CRISPR-Cas , Ciclo Celular/genética , Proliferação de Células , Reprogramação Celular , Embrião de Mamíferos , Células-Tronco Embrionárias/citologia , Epigênese Genética , Fibroblastos/citologia , Fibroblastos/metabolismo , Edição de Genes , Regulação da Expressão Gênica , Células HEK293 , Histonas/genética , Histonas/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Camundongos , Cultura Primária de Células , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transdução de Sinais , Fatores Associados à Proteína de Ligação a TATA/metabolismo
2.
Biochem Genet ; 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38363412

RESUMO

Highly polymorphic BCR-ABL kinase domains have been reported to harbor more than a hundred mutations, and among these, 40-60% have been identified as influencers of imatinib mesylate (IM) resistance. The emergence of IM resistance poses a significant challenge in the management of Chronic Myeloid Leukemia (CML). M351T (rs121913457), E255K (rs387906517), and Y253H (rs121913461) are of particular clinical significance due to their association with high-level imatinib resistance. This study was conducted to investigate the potential role of three significant SNPs in CML progression due to IM resistance. During the study period from 2018 to 2022 (48 months), the blood samples from 219 Reverse transcriptase-PCR-confirmed CML patients following RNA extraction and cDNA preparation were subjected to M351T, E255K, and Y253H mutation analysis by PCR-RFLP. After agarose gel visualization, the samples were subjected to Sanger sequencing to confirm the nucleotide change at the polymorphic loci. The wild-type genotype of all three ABL1 SNPs under investigation exhibits a significant reduction in frequency among IM non-responders compared to the responder group. The CGT haplotype frequency exhibits a significant difference between IM responder (4.2%) and non-responder (11.8%) (p = 0.002 < 0.05). Further, CGC haplotype was observed solely among the imatinib non-responder patients with a frequency percentage of 3.3% (p = 0.004), whereas the said genotype was absent among the responder group. A reduced overall survival rate was observed with deviation from wild-type genotype (M351T loci (T > C) with 1.217 times, E255K (G > A) with 1.485 and Y253H (T > C) with 1.399 times increase in hazard ratio) thereby enhancing mortality risk due to disease progression. The significant increase in the frequency of M351T, E255K, and Y253H loci among the IM non-responder group indicated their probable association with the development of IM resistance among CML patients. A haplotype frequency distribution pattern analysis of ABL1 loci further identified the CGC haplotype as an independent predictor for IM resistance. As such the study highlights the importance of patient characteristics, genotype distribution, and haplotype frequency distribution in predicting the response to IM treatment and clinical outcomes of CML patients.

3.
Inorg Chem ; 62(9): 3875-3885, 2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-36802595

RESUMO

The practical applicability of thiolated metal-organic frameworks (MOFs) remains challenging due to their low crystallinity and transient stability. Herein, we present a one-pot solvothermal synthesis process using varying ratios of 2,5-dimercaptoterephthalic acid (DMBD) and 1,4-benzene dicarboxylic acid (100/0, 75/25, 50/50, 25/75, and 0/100) to prepare stable mixed-linker UiO-66-(SH)2 MOFs (ML-U66SX). For each variant, the effects of different linker ratios on the crystallinity, defectiveness, porosity, and particle size have been discussed in detail. In addition, the impact of modulator concentration on these features has also been described. The stability of ML-U66SX MOFs was investigated under reductive and oxidative chemical conditions. The mixed-linker MOFs were used as sacrificial catalyst supports to highlight the interplay of template stability on the rate of the gold-catalyzed 4-nitrophenol hydrogenation reaction. The release of catalytically active gold nanoclusters originating from the framework collapse decreased with the controlled DMBD proportion, resulting in a 59% drop in the normalized rate constants (9.11-3.73 s-1 mg-1). In addition, post-synthetic oxidation (PSO) was used to further probe the stability of the mixed-linker thiol MOFs under harsh oxidative conditions. Following oxidation, the UiO-66-(SH)2 MOF underwent immediate structural breakdown, unlike other mixed-linker variants. Along with crystallinity, the microporous surface area of the post-synthetically oxidized UiO-66-(SH)2 MOF could be increased from 0 to 739 m2 g-1. Thus, the present study delineates a mixed-linker strategy to stabilize the UiO-66-(SH)2 MOF under harsh chemical conditions through meticulous thiol decoration.

4.
Reprod Domest Anim ; 58(2): 219-229, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36222382

RESUMO

In vitro culture and expansion of spermatogonial stem cells (SSCs) is an essential prerequisite to enhancing livestock productivity through SSC transplantation. Most of the culture media have been observed to be supplemented with serum. However, the use of serum in culture media may exert detrimental effects on SSC maintenance in vitro. An attempt was made to culture SSCs by replacing serum with 5% 'Knockout Serum Replacement (KSR)' in Doom pig (Sus domesticus), one of the valued indigenous germplasm of North-East India. Testes from 7 to 15 days old piglets were used for isolation, enrichment and in vitro culture of putative SSCs using serum-based and serum-free culture media. The cells were characterized for SSC-specific pluripotent markers expression by immunofluorescence staining and quantitative real-time PCR. The diameter and number of SSC colonies were recorded on days 9, 20 and 30 of culture. Similar morphologies of the SSC colonies were observed in both serum-based and serum-free culture conditions. Colony diameter and colony number were non-significantly higher in serum-free than serum-based media. The cells from both the culture conditions showed high alkaline phosphatase activity. The expression of SSC-specific pluripotent markers was observed in immunofluorescence and quantitative real-time PCR study. The present study revealed that SSCs from porcine species could be maintained in vitro for up to 30 days in serum-free culture using 5% KSR, which is believed to be a promising protein source for improving livestock production, and health care along with their conservation.


Assuntos
Espermatogônias , Testículo , Masculino , Animais , Suínos , Células Cultivadas , Testículo/metabolismo , Espermatogônias/metabolismo , Células-Tronco/metabolismo , Meios de Cultura
5.
Mol Cell ; 53(1): 32-48, 2014 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-24361252

RESUMO

Self-renewal and pluripotency of embryonic stem cells (ESCs) are established by multiple regulatory pathways operating at several levels. The roles of histone demethylases (HDMs) in these programs are incompletely defined. We conducted a functional RNAi screen for HDMs and identified five potential HDMs essential for mouse ESC identity. In-depth analyses demonstrate that the closely related HDMs Jmjd2b and Jmjd2c are necessary for self-renewal of ESCs and induced pluripotent stem cell generation. Genome-wide occupancy studies reveal that Jmjd2b unique, Jmjd2c unique, and Jmjd2b-Jmjd2c common target sites belong to functionally separable Core, Polycomb repressive complex (PRC), and Myc regulatory modules, respectively. Jmjd2b and Nanog act through an interconnected regulatory loop, whereas Jmjd2c assists PRC2 in transcriptional repression. Thus, two HDMs of the same subclass exhibit distinct and combinatorial functions in control of the ESC state. Such complexity of HDM function reveals an aspect of multilayered transcriptional control.


Assuntos
Células-Tronco Embrionárias/enzimologia , Histona Desmetilases com o Domínio Jumonji/metabolismo , Células-Tronco Pluripotentes/enzimologia , Transcrição Gênica/fisiologia , Animais , Linhagem Celular , Células-Tronco Embrionárias/citologia , Estudo de Associação Genômica Ampla , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Histona Desmetilases com o Domínio Jumonji/genética , Camundongos , Proteína Homeobox Nanog , Células-Tronco Pluripotentes/citologia , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo
6.
J Digit Imaging ; 35(3): 408-423, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35166968

RESUMO

CompreHensive Digital ArchiVe of Cancer Imaging - Radiation Oncology (CHAVI-RO) is a multi-tier WEB-based medical image databank. It supports archiving de-identified radiological and clinical datasets in a relational database. A semantic relational database model is designed to accommodate imaging and treatment data of cancer patients. It aims to provide key datasets to investigate and model the use of radiological imaging data in response to radiation. This domain of research area addresses the modeling and analysis of complete treatment data of oncology patient. A DICOM viewer is integrated for reviewing the uploaded de-identified DICOM dataset. In a prototype system we carried out a pilot study with cancer data of four diseased sites, namely breast, head and neck, brain, and lung cancers. The representative dataset is used to estimate the data size of the patient. A role-based access control module is integrated with the image databank to restrict the user access limit. We also perform different types of load tests to analyze and quantify the performance of the CHAVI databank.


Assuntos
Neoplasias , Sistemas de Informação em Radiologia , Radiologia , Bases de Dados Factuais , Humanos , Projetos Piloto , Software
7.
J Biol Chem ; 295(47): 15797-15809, 2020 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-32994224

RESUMO

Regulatory elements (REs) consist of enhancers and promoters that occupy a significant portion of the noncoding genome and control gene expression programs either in cis or in trans Putative REs have been identified largely based on their regulatory features (co-occupancy of ESC-specific transcription factors, enhancer histone marks, and DNase hypersensitivity) in mouse embryonic stem cells (mESCs). However, less has been established regarding their regulatory functions in their native context. We deployed cis- and trans-regulatory elements scanning through saturating mutagenesis and sequencing (ctSCAN-SMS) to target elements within the ∼12-kb cis-region (cis-REs; CREs) of the Oct4 gene locus, as well as genome-wide 2,613 high-confidence trans-REs (TREs), in mESCs. ctSCAN-SMS identified 10 CREs and 12 TREs as novel candidate REs of the Oct4 gene in mESCs. Furthermore, deletions of these candidate REs confirmed that the majority of the REs are functionally active, and CREs are more active than TREs in controlling Oct4 gene expression. A subset of active CREs and TREs physically interact with the Oct4 promoter to varying degrees; specifically, a greater number of active CREs, compared with active TREs, physically interact with the Oct4 promoter. Moreover, comparative genomics analysis reveals that a greater number of active CREs than active TREs are evolutionarily conserved between mice and primates, including humans. Taken together, our study demonstrates the reliability and robustness of ctSCAN-SMS screening to identify critical REs and investigate their roles in the regulation of transcriptional output of a target gene (in this case Oct4) in their native context.


Assuntos
Loci Gênicos , Células-Tronco Embrionárias Murinas/metabolismo , Fator 3 de Transcrição de Octâmero/metabolismo , Elementos Reguladores de Transcrição , Animais , Sistemas CRISPR-Cas , Linhagem Celular , Estudo de Associação Genômica Ampla , Humanos , Camundongos , Células-Tronco Embrionárias Murinas/citologia , Fator 3 de Transcrição de Octâmero/genética
8.
Sensors (Basel) ; 20(23)2020 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-33287233

RESUMO

This research work focuses on the development of a piezoelectric magnetostrictive smart composite with advanced sensing capability. The composite piezoelectric property is achieved from the dispersion of single-walled carbon nanotubes (SWCNTs) and the magnetostrictive property from Terfenol-D nanoparticles. Finite element analysis (FEA) is used to examine the feasibility of modelling the piezoelectric (change in electric field) and magnetostrictive (change in magnetic field) self-sensing responses in the presence of applied stress. The numerical work was coupled with a series of mechanical tests to characterize the piezoelectric response, magnetostriction response and mechanical strength. Tensile tests of the composite samples manufactured as is (virgin), samples with SWCNTs, samples with Terfenol-D nanoparticles and samples with both SWCNTs and Terfenol-D nanoparticles were conducted. It was observed that an increase in volume fraction of Terfenol-d nanoparticles increases the change in magnetization, therefore increasing voltage response up to the point of saturation. The optimum change in amplitude was observed with 0.35% volume fraction of Terfenol-D nanoparticles. A constant ratio of SWCNTs was maintained, and maximum change in electrical resistance was at 7.4%. Fracture toughness for the samples with all nanoparticles was explored, and the results showed improved resistance to crack propagation.

9.
J Med Syst ; 44(5): 99, 2020 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-32240368

RESUMO

We propose a de-identification system which runs in a standalone mode. The system takes care of the de-identification of radiation oncology patient's clinical and annotated imaging data including RTSTRUCT, RTPLAN, and RTDOSE. The clinical data consists of diagnosis, stages, outcome, and treatment information of the patient. The imaging data could be the diagnostic, therapy planning, and verification images. Archival of the longitudinal radiation oncology verification images like cone beam CT scans along with the initial imaging and clinical data are preserved in the process. During the de-identification, the system keeps the reference of original data identity in encrypted form. These could be useful for the re-identification if necessary.


Assuntos
Anonimização de Dados/normas , Registros Eletrônicos de Saúde/organização & administração , Radioterapia (Especialidade)/organização & administração , Tomografia Computadorizada de Feixe Cônico/métodos , Registros Eletrônicos de Saúde/normas , Humanos , Processamento de Imagem Assistida por Computador/métodos , Radioterapia (Especialidade)/normas
10.
Emerg Infect Dis ; 25(7): 1261-1270, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31211665

RESUMO

During March 13-June 23, 2018, anthrax-like cutaneous lesions attributed to the Bacillus cereus group of organisms developed in 12 newborns in India. We traced the source of infection to the healthcare kits used for newborn care. We used multilocus sequence typing to characterize the 19 selected strains from various sources in hospital settings, including the healthcare kits. This analysis revealed the existence of a genetically diverse population comprising mostly new sequence types. Phylogenetic analysis clustered most strains into the previously defined clade I, composed primarily of pathogenic bacilli. We suggest that the synergistic interaction of nonhemolytic enterotoxin and sphingomyelinase might have a role in the development of cutaneous lesions. The infection was controlled by removing the healthcare kits and by implementing an ideal housekeeping program. All the newborns recovered after treatment with ciprofloxacin and amikacin.


Assuntos
Bacillus cereus , Infecções por Bactérias Gram-Positivas/epidemiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Dermatopatias Bacterianas/epidemiologia , Dermatopatias Bacterianas/microbiologia , Antraz/diagnóstico , Bacillus cereus/classificação , Bacillus cereus/genética , Proteínas de Bactérias/genética , Infecção Hospitalar/diagnóstico , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Diagnóstico Diferencial , Enterotoxinas/genética , Infecções por Bactérias Gram-Positivas/diagnóstico , Humanos , Índia/epidemiologia , Lactente , Recém-Nascido , Tipagem de Sequências Multilocus , Filogenia , Vigilância em Saúde Pública , Dermatopatias Bacterianas/diagnóstico
11.
Inorg Chem ; 57(21): 13713-13727, 2018 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-30339375

RESUMO

Aliphatic thiolato-S-bridged tri- and binuclear nickel(II) complexes have been synthesized and characterized as models for the Nip site of the A cluster of acetyl coenzyme A synthase (ACS)/carbon monooxide (CO) dehydrogenase. Reaction of the in situ formed N2Sthiol donor ligands with [Ni(H2O)6](ClO4)2 afforded the trinuclear complexes [Ni{(LMe(S))2Ni}2](ClO4)2·CH3CN (1·CH3CN) and [Ni{(LBr(S))2Ni}2](ClO4)2·5H2O (2·5H2O) following self-assembly. Complexes 1 and 2 react with [Ni(dppe)Cl2] and dppe [dppe = 1,2-bis(diphenylphosphino)ethane] to afford the binuclear [Ni(dppe)Ni(LMe(S))2](ClO4)2·2H2O (3·2H2O) and [Ni(dppe)Ni(LBr(S))2](ClO4)2·0.75O(C2H5)2 [4·0.75O(C2H5)2], respectively. The X-ray crystal structures of 1-4 revealed a central NiIIS4 moiety in 1 and 2 and a NiIIP2S2 moiety in 3 and 4; both moieties have a square-planar environment around Ni and may mimic the properties of the Nip site of ACS. The electrochemical reduction of both terminal NiII ions of 1 and 2 occurs simultaneously, which is further confirmed by the isolation of [Ni{(LMe(S))2Ni(NO)}2](ClO4)2 (5) and [Ni{(LBr(S))2Ni(NO)}2](ClO4)2 (6) following reductive nitrosylation of 1 and 2. Complexes 5 and 6 exhibit νNO at 1773 and 1789 cm-1, respectively. In the presence of O2, both 5 and 6 transform to nitrite-bound monomers [(LMe(S-S))Ni(NO2)](ClO4) (7) and [(LBr(S-S))Ni(NO2)](ClO4)2 (8). The nature of the ligand modification is evident from the X-ray crystal structure of 7. To understand the origin of multiple reductive responses of 1-4, complex [(LMe(SMe))2Ni](ClO4)2 (9) is considered. The central NiS4 part of 1 is labile like the Nip site of ACS and can be replaced by phenanthroline. The treatment of CO to reduce 3 generates a 3red-(CO)2 species, as confirmed by Fourier transform infrared (νCO = 1997 and 2068 cm-1) and electron paramagnetic resonance ( g1 = 2.18, g2 = 2.13, g3 = 1.95, and AP = 30-80 G) spectroscopy. The CO binding to NiI of 3red is relevant to the ACS activity.


Assuntos
Acetato-CoA Ligase/química , Aldeído Oxirredutases/química , Complexos de Coordenação/química , Técnicas Eletroquímicas , Complexos Multienzimáticos/química , Níquel/química , Acetato-CoA Ligase/metabolismo , Aldeído Oxirredutases/metabolismo , Complexos de Coordenação/síntese química , Complexos de Coordenação/metabolismo , Cristalografia por Raios X , Modelos Moleculares , Estrutura Molecular , Complexos Multienzimáticos/metabolismo , Níquel/metabolismo
12.
Indian J Med Res ; 145(5): 635-640, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28948954

RESUMO

BACKGROUND & OBJECTIVES: Candida, the most common opportunistic infection in acquired immunodeficiency syndrome (AIDS), attributes its pathogenicity to its virulence factors, mainly the biofilms, the proteinases and the phospholipases. There is a significant interplay of these factors during the HIV infection. This study was aimed to estimate the biofilm, proteinase and phospholipase production in Candida species isolated from the oropharyngeal samples in the HIV-infected patients. METHODS: A total of 126 consecutive HIV-positive patients were screened for Candida growth using oropharyngeal swabs. Identification was done by Gram staining, germ tube test, chlamydospore identification, chromagar and biochemical tests on Vitek 2. Biofilm production was observed on Sabouraud's dextrose broth with glucose, phospholipase production in egg yolk agar medium and proteinase production in bovine serum albumin agar medium. RESULTS: Of a total of 126 patients, 53 (42.06%) showed Candida growth: Candida albicans (n=46, 86.8%) was most common followed by the non-albicans Candida (NAC) (n=7, 13.93%). Of a total 33 (62.3%) biofilm positive isolates, significant production was observed in the NAC species (P <0.05). C. albicans reported the highest phospholipase (n=37/41, 90.24%) and proteinase (n=37/43, 86%) activities in a total of 41 (77%) phospholipase positive and 43 (81.1%) proteinase positive isolates. INTERPRETATION & CONCLUSIONS: Although C. albicans was the most common Candida species identified in HIV positive patients, the emergence of NAC was of special concern. Virulence factors such as biofilms, proteinases and phospholipases were noted in both these groups. Further research is required for better understanding of the pathogenic role of Candida species so as to aid in therapeutic interventions.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Biofilmes/crescimento & desenvolvimento , Candida albicans/enzimologia , Infecções por HIV/microbiologia , Infecções Oportunistas Relacionadas com a AIDS/enzimologia , Infecções Oportunistas Relacionadas com a AIDS/genética , Adulto , Candida albicans/patogenicidade , Feminino , Infecções por HIV/enzimologia , Infecções por HIV/virologia , Humanos , Masculino , Peptídeo Hidrolases/biossíntese , Fosfolipases/biossíntese
13.
Indian J Med Res ; 143(4): 495-501, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27377507

RESUMO

BACKGROUND & OBJECTIVES: The changing spectrum of Candida species in causation of oropharyngeal candidiasis and their antifungal susceptibility pattern among the HIV infected individuals has made the identification to species level mandatory and detection of drug resistance necessary for patient care. The present study was carried out to determine the species distribution and antifungal susceptibility profile of oral Candida isolates colonizing or infecting both HIV seropositive and seronegative individuals. METHODS: A case-control study was conducted including 141 consecutive, non-repeat HIV-seropositive individuals and an equal number of sex and age matched HIV-seronegative control. Speciation of the oropharyngeal Candida isolates was done using standard yeast identification protocol. Antifungal susceptibility testing was done by the disk-diffusion method as well as by Fungitest method. RESULTS: From the 59 culture positive HIV seropositive cases, 61 Candida isolates were recovered; Candidaalbicans (n=47, 77.0%), C. dubliniensis (n=9, 14.7%), C. parapsilosis (n=2, 3.2%), C. glabrata (n=2, 3.2%), and C. famata (n=1, 1.6%). Candida colonization in HIV-seropositive individuals was significantly higher than that of HIV-seronegative (control) group. Antifungal susceptibility testing revealed (n=6, 9.3%) C. albicans isolates resistant to voriconazole and fluconazole by disk-diffusion method whereas no resistance was seen by Fungitest method. INTERPRETATION & CONCLUSIONS: C. albicans was the commonest Candida species infecting or colonizing HIV seropositive individuals. Oropharyngeal Candida isolates had high level susceptibility to all the major antifungals commonly in use. Increased level of immunosuppression in HIV-seropositives and drug resistance of non-albicans Candida species makes identification and susceptibility testing of Candida species necessary in different geographical areas of the country.


Assuntos
Candida/genética , Candidíase/tratamento farmacológico , Farmacorresistência Fúngica/genética , Soropositividade para HIV/genética , Adolescente , Adulto , Idoso , Terapia Antirretroviral de Alta Atividade/métodos , Candida/efeitos dos fármacos , Candida/crescimento & desenvolvimento , Candidíase/genética , Candidíase/microbiologia , Candidíase/virologia , Criança , Pré-Escolar , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Feminino , Fluconazol/farmacologia , HIV/genética , HIV/patogenicidade , Infecções por HIV/tratamento farmacológico , Infecções por HIV/microbiologia , Infecções por HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Orofaringe/microbiologia , Orofaringe/patologia , Orofaringe/virologia , Voriconazol/farmacologia
15.
Inorg Chem ; 53(20): 10797-9, 2014 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-25285476

RESUMO

In this Communication, we report a facile approach to synthesize a technologically important oxide Zn2SnO4 (ZTO) by a temperature-dependent solid-state reaction without the Kirkendall effect. Single-phase defect-free ZTO was formed upon calcination of a homogeneous 2:1 mixture of reactive ZnO rods and SnO2 nanoparticles at 1000 °C. We also observed interesting photocatalytic and photovoltaic properties from the synthesized ZTO material.

16.
Inorg Chem ; 53(8): 3961-72, 2014 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-24684654

RESUMO

We have carried out the effect of post annealing temperatures on the performance of solution-grown ZnO rods as photoanodes in dye-sensitized solar cells. Keeping our basic objective of exploring the effect of native defects on the performance of DSSC, we have synthesized ZnO rods having length in the range of 2-5 µm by a modified sonication-induced precipitation technique. We performed extensive characterization on the samples annealed at various temperatures and confirmed that annealing at 300 °C results in ZnO rods with minimum native defects that have been identified as doubly ionized oxygen vacancies. The electron paramagnetic resonance measurements on the samples, on the other hand, confirmed the presence of shallow donors in the low temperature annealed samples. We also carried out electrochemical impedance measurements to understand the transport properties at different interfaces in the solar cell assembly. We could conclude that solution-processed ZnO rods annealed at 300 °C are better suited for fabricating DSSC with improved efficiency (1.57%), current density (5.11 mA/cm(2)), and fill factor (45.29%). On the basis of our results, we were able to establish a close connection between the defects in the metal oxide electron transporting nano system and the DSSC performance.

17.
Environ Monit Assess ; 186(5): 2885-93, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24374763

RESUMO

There is an established evidence that exposure to high levels of road traffic noise is associated with elevated risk of coronary heart disease (CHD). The results however have been heterogeneous and mostly inconclusive. The present investigation aimed to examine this association in adult subjects, with a secondary aim of identifying potentially vulnerable sub-populations. Similar studies have never been reported from Indian population. For exposure assessment, the time-weighted road traffic noise indicator, L den, was used as a continuous and categorical predictor. A cross-sectional study was designed, and sociodemographic and lifestyle- and health-related characteristics were recorded for 909 (533 females and 376 males) subjects aged 18-80 years. The respondents living in areas with L den < 60 dB(A) were designated as the reference group. Odds for self-reported CHD in relation to traffic noise exposure were estimated by univariate and multifactorial logistic regression with adjustments for potential confounders and effect modifiers. The adjusted odds ratio (OR) for self-reported CHD was 1.72 (95 % CI 1.36-2.19) per 5 dB(A) increase of L den (range 55-80 dB(A)). A gender-related risk difference was observed among male (OR 1.47 (1.07-2.02)) and female (OR 1.83 (1.27-2.65)) respondents. A stronger effect for subjects in the age group 55-64 years old was found, with age, residence period, body mass index, and self-reported stress being significant confounders. This study suggests epidemiological evidence that exposure to road traffic noise of L den > 65 dB(A) may be associated with occurrence of CHD in adult subjects. A trend was observed indicating increasing risk with higher exposure levels. The study results are also suggestive of higher risk of outcome among those with other chronic ailments (diabetes, pulmonary, or renal issues) and residing in the same location in excess of 15 years. Orientation of bedroom windows was identified as a significant effect modifier.


Assuntos
Doença das Coronárias/epidemiologia , Ruído dos Transportes , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Exposição Ambiental/análise , Exposição Ambiental/estatística & dados numéricos , Monitoramento Ambiental , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prevalência , Risco , Autorrelato , Adulto Jovem
18.
J Colloid Interface Sci ; 665: 988-998, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38574587

RESUMO

In applications utilizing Covalent Organic Frameworks (COFs) for adsorption, the interplay between crystallinity (vis-à-vis surface area) and active sites still remains ambiguous. To address this, the present study introduces three isoreticular COFs-COP-N18 (covalent organic polymer with short-range order), COF-N18 (COF having long-range order), and COF-N27 (semicrystalline COF with pyridyl heteroatoms)-to explore this duality. Through systematic variations in structural order, pore volume, and pore-wall nitrogen content, we aim to establish a structure-activity relationship (SAR) for these COFs via adsorption and catalysis, using CO2 and I2 as probes. Our investigation highlights the positive influence of crystallinity, surface area, and pore volume in adsorption as well as catalysis. However, the presence of heteroatoms manifests complex behavior in CO2 adsorption and CO2 cycloaddition reactions with epoxides. COF-N18 and COF-N27 showed comparable CO2 uptake capacities at different temperatures (273, 293, and 313 K) and ∼1 bar pressure. Additionally, CO2 cycloaddition reactions were performed with substrates possessing different polarities (epichlorohydrin, 1,2-epoxydodecane) to elucidate the role of COF surface polarity. Further investigation into iodine adsorption was performed to understand the impact of COF structural features on the modes of adsorption and adsorption kinetics. Improvements in COF-crystallinity results in faster average iodine uptake rate at 80% (K80% = 1.79 g/h) by COF-N18. Whereas, heteroatom doping slows down iodine adsorption kinetics (0.35 g/h) by prolonging the adsorption process up to 72 h. Overall, this study advances our understanding of COFs as adsorbents and catalysts, providing key insights into their SAR while emphasizing structural fine-tuning as a key factor for impactful environmental applications.

19.
Cell Rep ; 43(3): 113858, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38416645

RESUMO

RNA has been implicated in the recruitment of chromatin modifiers, and previous studies have provided evidence in favor and against this idea. RNase treatment of chromatin is commonly used to study RNA-mediated regulation of chromatin modifiers, but the limitations of this approach remain unclear. RNase A treatment during chromatin immunoprecipitation (ChIP) reduces chromatin occupancy of the H3K27me3 methyltransferase Polycomb repressive complex 2 (PRC2). This led to suggestions of an "RNA bridge" between PRC2 and chromatin. Here, we show that RNase A treatment during ChIP causes the apparent loss of all facultative heterochromatin, including both PRC2 and H3K27me3 genome-wide. We track this observation to a gain of DNA from non-targeted chromatin, sequenced at the expense of DNA from facultative heterochromatin, which reduces ChIP signals. Our results emphasize substantial limitations in using RNase A treatment for mapping RNA-dependent chromatin occupancy and invalidate conclusions that were previously established for PRC2 based on this assay.


Assuntos
Cromatina , Complexo Repressor Polycomb 2 , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Histonas/genética , RNA/genética , Heterocromatina , Ribonuclease Pancreático , Artefatos , DNA
20.
Viral Immunol ; 37(3): 149-158, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38573237

RESUMO

Hepatitis B Virus (HBV) is posing as a serious public health threat mainly due to its asymptomatic nature of infection in pregnancy and vertical transmission. Viral sensing toll-like receptors (TLR) and Interleukins (IL) are important molecules in providing an antiviral state. The study aimed to assess the role of TLR7-mediated immune modulation, which might have an impact in the intrauterine transmission of HBV leading to mother to child transmission of the virus. We investigated the expression pattern of TLR7, IL-3, and IL-6 by RT-PCR in the placentas of HBV-infected pregnant women to see their role in the intrauterine transmission of HBV. We further validated the expression of TLR7 in placentas using Immunohistochemistry. Expression analysis by RT-PCR of TLR7 revealed significant downregulation among the Cord blood (CB) HBV DNA positive and negative cases with mean ± standard deviation (SD) of 0.43 ± 0.22 (28) and 1.14 ± 0.57 (44) with p = 0.001. IL-3 and IL-6 expression revealed significant upregulation in the CB HBV DNA-positive cases with p = 0.001. Multinomial logistic regression analysis revealed that TLR7 and IL-3 fold change and mother HBeAg status are important predictors for HBV mother to child transmission. Immunohistochemistry revealed the decreased expression of TLR7 in CB HBV DNA-positive cases. This study reveals that the downregulation of TLR7 in the placenta along with CB HBV DNA-positive status may lead to intrauterine transmission of HBV, which may lead to vertical transmission of HBV.


Assuntos
Hepatite B , Complicações Infecciosas na Gravidez , Feminino , Humanos , Gravidez , DNA Viral , Antígenos E da Hepatite B , Antígenos de Superfície da Hepatite B , Vírus da Hepatite B , Transmissão Vertical de Doenças Infecciosas , Interleucina-3 , Interleucina-6/genética , Receptor 7 Toll-Like/genética , Recém-Nascido
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