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1.
Nat Immunol ; 18(2): 184-195, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27992400

RESUMO

Invariant natural killer T cells (iNKT cells) are innate-like lymphocytes that protect against infection, autoimmune disease and cancer. However, little is known about the epigenetic regulation of iNKT cell development. Here we found that the H3K27me3 histone demethylase UTX was an essential cell-intrinsic factor that controlled an iNKT-cell lineage-specific gene-expression program and epigenetic landscape in a demethylase-activity-dependent manner. UTX-deficient iNKT cells exhibited impaired expression of iNKT cell signature genes due to a decrease in activation-associated H3K4me3 marks and an increase in repressive H3K27me3 marks within the promoters occupied by UTX. We found that JunB regulated iNKT cell development and that the expression of genes that were targets of both JunB and the iNKT cell master transcription factor PLZF was UTX dependent. We identified iNKT cell super-enhancers and demonstrated that UTX-mediated regulation of super-enhancer accessibility was a key mechanism for commitment to the iNKT cell lineage. Our findings reveal how UTX regulates the development of iNKT cells through multiple epigenetic mechanisms.


Assuntos
Diferenciação Celular , Epigênese Genética , Regulação da Expressão Gênica , Histona Desmetilases/metabolismo , Células T Matadoras Naturais/fisiologia , Animais , Linhagem da Célula , Células Cultivadas , Elementos Facilitadores Genéticos/genética , Histona Desmetilases/genética , Imunidade Inata/genética , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Especificidade de Órgãos , Regiões Promotoras Genéticas/genética , Proteína com Dedos de Zinco da Leucemia Promielocítica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
2.
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
3.
Nature ; 586(7827): 101-107, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32939092

RESUMO

The reprogramming of human somatic cells to primed or naive induced pluripotent stem cells recapitulates the stages of early embryonic development1-6. The molecular mechanism that underpins these reprogramming processes remains largely unexplored, which impedes our understanding and limits rational improvements to reprogramming protocols. Here, to address these issues, we reconstruct molecular reprogramming trajectories of human dermal fibroblasts using single-cell transcriptomics. This revealed that reprogramming into primed and naive pluripotency follows diverging and distinct trajectories. Moreover, genome-wide analyses of accessible chromatin showed key changes in the regulatory elements of core pluripotency genes, and orchestrated global changes in chromatin accessibility over time. Integrated analysis of these datasets revealed a role for transcription factors associated with the trophectoderm lineage, and the existence of a subpopulation of cells that enter a trophectoderm-like state during reprogramming. Furthermore, this trophectoderm-like state could be captured, which enabled the derivation of induced trophoblast stem cells. Induced trophoblast stem cells are molecularly and functionally similar to trophoblast stem cells derived from human blastocysts or first-trimester placentas7. Our results provide a high-resolution roadmap for the transcription-factor-mediated reprogramming of human somatic cells, indicate a role for the trophectoderm-lineage-specific regulatory program during this process, and facilitate the direct reprogramming of somatic cells into induced trophoblast stem cells.


Assuntos
Reprogramação Celular/genética , Regulação da Expressão Gênica , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Trofoblastos/citologia , Trofoblastos/metabolismo , Adulto , Cromatina/genética , Cromatina/metabolismo , Ectoderma/citologia , Ectoderma/metabolismo , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Transcrição Gênica
4.
J Am Chem Soc ; 146(8): 5108-5117, 2024 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-38367279

RESUMO

Enzymes are natural catalysts for a wide range of metabolic chemical transformations, including selective hydrolysis, oxidation, and phosphorylation. Herein, we demonstrate a strategy for the encapsulation of enzymes within a highly stable zirconium-based metal-organic framework. UiO-66-F4 was synthesized under mild conditions using an enzyme-compatible amino acid modulator, serine, at a modest temperature in an aqueous solution. Enzyme@UiO-66-F4 biocomposites were then formed by an in situ encapsulation route in which UiO-66-F4 grows around the enzymes and, consequently, provides protection for the enzymes. A range of enzymes, namely, lysozyme, horseradish peroxidase, and amano lipase, were successfully encapsulated within UiO-66-F4. We further demonstrate that the resulting biocomposites are stable under conditions that could denature many enzymes. Horseradish peroxidase encapsulated within UiO-66-F4 maintained its biological activity even after being treated with the proteolytic enzyme pepsin and heated at 60 °C. This strategy expands the toolbox of potential metal-organic frameworks with different topologies or functionalities that can be used as enzyme encapsulation hosts. We also demonstrate that this versatile process of in situ encapsulation of enzymes under mild conditions (i.e., submerged in water and at a modest temperature) can be generalized to encapsulate enzymes of various sizes within UiO-66-F4 while protecting them from harsh conditions (i.e., high temperatures, contact with denaturants or organic solvents).


Assuntos
Estruturas Metalorgânicas , Compostos Organometálicos , Ácidos Ftálicos , Estruturas Metalorgânicas/química , Zircônio/química , Biomimética , Compostos Organometálicos/química , Peroxidase do Rábano Silvestre
5.
J Am Chem Soc ; 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-39073091

RESUMO

In reticular chemistry, molecular building blocks are designed to create crystalline open frameworks. A key principle of reticular chemistry is that the most symmetrical networks are the likely outcomes of reactions, particularly when highly symmetrical building blocks are involved. The strategy of synthesizing low-dimensional networks aims to reduce explicitly the symmetry of the molecular building blocks. Here we report the spontaneous formation of hydrogen-bonded fibrous structures from trigonal prismatic building blocks, which were designed to form three-dimensional crystalline networks on account of their highly symmetrical structures. Utilizing different microscopic and spectroscopic techniques, we identify the structures at the early stages of the assembly process in order to and understand the growth mechanism. The symmetrical molecular building blocks are incorporated preferentially in the longitudinal direction, giving rise to anisotropic hydrogen-bonded porous organic nanotubes. Entropy-driven anisotropic growth provides micrometer-scale unidirectional nanotubes with high porosity. By combining experimental evidence and theoretical modeling, we have obtained a deep understanding of the nucleation and growth processes. Our findings offer fundamental insight into the molecular design of tubular structures. The nanotubes evolve further in the transverse directions to provide extended higher-order fibrous structures [nano- and microfibers], ultimately leading to large-scale interconnected hydrogen-bonded fiber-like structures with twists and turns. Our work provides fundamental understanding and paves the way for innovative molecular designs in low-dimensional networks.

6.
Nucleic Acids Res ; 50(8): 4500-4514, 2022 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-35451487

RESUMO

Histone H3.3 is an H3 variant which differs from the canonical H3.1/2 at four residues, including a serine residue at position 31 which is evolutionarily conserved. The H3.3 S31 residue is phosphorylated (H3.3 S31Ph) at heterochromatin regions including telomeres and pericentric repeats. However, the role of H3.3 S31Ph in these regions remains unknown. In this study, we find that H3.3 S31Ph regulates heterochromatin accessibility at telomeres during replication through regulation of H3K9/K36 histone demethylase KDM4B. In mouse embryonic stem (ES) cells, substitution of S31 with an alanine residue (H3.3 A31 -phosphorylation null mutant) results in increased KDM4B activity that removes H3K9me3 from telomeres. In contrast, substitution with a glutamic acid (H3.3 E31, mimics S31 phosphorylation) inhibits KDM4B, leading to increased H3K9me3 and DNA damage at telomeres. H3.3 E31 expression also increases damage at other heterochromatin regions including the pericentric heterochromatin and Y chromosome-specific satellite DNA repeats. We propose that H3.3 S31Ph regulation of KDM4B is required to control heterochromatin accessibility of repetitive DNA and preserve chromatin integrity.


Assuntos
Heterocromatina , Histonas , Animais , Camundongos , Histonas/genética , Histonas/metabolismo , Heterocromatina/genética , Histona Desmetilases/metabolismo , Fosforilação , Montagem e Desmontagem da Cromatina
7.
BMC Public Health ; 24(1): 676, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38439011

RESUMO

BACKGROUND: Reproductive span is the foundation of every woman's health in later life. India is currently facing a growing burden of multiple morbidities among the women in their reproductive age group which may further increase over the coming decades. The purpose of the present study aimed to identify different modifiable and non-modifiable risk factors affecting multimorbidity among the women in reproductive age group in Indian context. METHODS: Secondary data were obtained from the Demography and Health Survey (DHS), conducted in India during 2019-2021. A total of 671,967 women aged 15-49 years were selected for this present study. Descriptive, association studies and multinominal logistic regression analyses were performed to accomplish the objectives. RESULTS: Currently, 6.3% of total study participant's reproductive age group women suffered from multimorbidity in India. Never consuming protein, fruits, vegetables and milk increase the chances of developing multimorbidity. Consumption of fried foods, aerated drinks and addiction towards tobacco and alcohol also has a greater influence on the prevalence of multimorbidity. The prevalence of multimorbidity is sharply increased with increasing age and Body Mass Index (BMI). Regionally, the prevalence of multimorbidity was found more among the women hailed from eastern and north-eastern India. CONCLUSION: To reduce the risk of developing multimorbidity, targeted interventions are needed in the form of educating every woman concerning the importance of having minimum health-related knowledge, maintaining healthy lifestyle, weight management and having proper and balanced diet.


Assuntos
Comportamento Aditivo , Multimorbidade , Adulto , Feminino , Humanos , Povo Asiático , Frutas , Índia/epidemiologia , Adolescente , Adulto Jovem , Pessoa de Meia-Idade
8.
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.

9.
Sensors (Basel) ; 24(9)2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38733050

RESUMO

Gait phase monitoring wearable sensors play a crucial role in assessing both health and athletic performance, offering valuable insights into an individual's gait pattern. In this study, we introduced a simple and cost-effective capacitive gait sensor manufacturing approach, utilizing a micropatterned polydimethylsiloxane dielectric layer placed between screen-printed silver electrodes. The sensor demonstrated inherent stretchability and durability, even when the electrode was bent at a 45-degree angle, it maintained an electrode resistance of approximately 3 Ω. This feature is particularly advantageous for gait monitoring applications. Furthermore, the fabricated flexible capacitive pressure sensor exhibited higher sensitivity and linearity at both low and high pressure and displayed very good stability. Notably, the sensors demonstrated rapid response and recovery times for both under low and high pressure. To further explore the capabilities of these new sensors, they were successfully tested as insole-type pressure sensors for real-time gait signal monitoring. The sensors displayed a well-balanced combination of sensitivity and response time, making them well-suited for gait analysis. Beyond gait analysis, the proposed sensor holds the potential for a wide range of applications within biomedical, sports, and commercial systems where soft and conformable sensors are preferred.


Assuntos
Marcha , Pressão , Dispositivos Eletrônicos Vestíveis , Tecnologia sem Fio , Humanos , Marcha/fisiologia , Tecnologia sem Fio/instrumentação , Análise da Marcha/métodos , Análise da Marcha/instrumentação , Eletrodos , Sapatos , Desenho de Equipamento
10.
Environ Monit Assess ; 196(7): 600, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849696

RESUMO

Herbal waste produced during the manufacturing of herbal products is a potential feedstock for anaerobic digestion due to high amount of organic matter that can be transformed into biogas as an energy resource. Therefore, the present study was undertaken to convert herbal waste produced during the manufacturing of common of Ayurveda products into biogas through anaerobic digestion process using batch test study under controlled mesophilic temperature conditions of 35 °C with food to inoculum ratio of 0.75. The maximum biomethane potential (BMP) of 0.90 (gCH4COD/g CODfed) and sludge activity of 0.70 (gCH4-CD/gVSS) was exhibited by WS herbal waste owing to its high chemical oxygen demand (COD) of 4 g/g and better solubilization potential of the organic matter showing change in volatile suspended solids (ΔVSS) of 79%. On the other hand, the waste derived from the TA herb, exhibited the least biogas yield of 0.55 (gCH4COD/g CODfed) and sludge activity of 0.40 (gCH4-CD/gVSS), albeit with higher organic matter present. This was due to the possible hindrance of waste solubilization by the presence of lignin. The waste derived from VVL and PE showed intermediate BMP and sludge activity. The methane generation rate constant (k), a key indicator of the biodegradation potential, was also evaluated. The k values showed similar trend as of BMP values ranging from 0.081 to 0.15 d-1 thus indicating the influence of presence of lignin and the change in ΔVSS. The present study proves anaerobic digestion to be an alternative treatment method to be a milestone for management of herbal wastes and can be successfully implemented on real-scale systems.


Assuntos
Biocombustíveis , Anaerobiose , Metano/análise , Análise da Demanda Biológica de Oxigênio , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Reatores Biológicos , Resíduos Industriais/análise
11.
J Ethn Subst Abuse ; : 1-24, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38613768

RESUMO

BACKGROUND: Alcohol consumption among tribal male adolescents in India is a significant social concern. Tribal adolescents are particularly vulnerable and tend to lean toward alcohol addiction. Therefore, it is crucial to introduce some necessary footsteps to reduce alcohol consumption. The primary objective of this study is to investigate the association of various latent factors with the alcohol-drinking behavior of tribal adolescents. METHODS: The study collected data from 600 tribal adolescents from the Dooars region, with 241 of them reported consuming alcohol. The study aimed to confirm the theoretical development of hypotheses regarding peer pressure, parental discord, stress, attitude toward alcohol, and food insecurity as exogenous latent factors influencing the alcohol-drinking behavior of tribal adolescents. In this context, the study adopted both measurement and structural models using Partial Least Squares-Structural Equation Modeling (PLS-SEM). RESULTS: The findings revealed a significant path relationship between alcohol drinking behavior and various exogenous factors like peer pressure (ß = 0.214, p = .000), parental discord (ß = 0.121, p = .009), stress (ß = 0.170, p = .000), attitude toward alcohol (ß = 0.110, p = .004), and food insecurity (ß = 0.510, p = .000). This study developed a reflective measurement model, and the evaluation of reflective measurement models was conducted, assessing internal consistency, convergent validity, and discriminant validity, yielding satisfactory results. CONCLUSION: To tackle alcohol issues among tribal adolescents in the Dooars region, effective strategies should be employed. These include educating in schools, highlighting tribal role models, aiding peers with alcohol dependence, providing life skills training, and addressing parental discord and food insecurity through awareness campaigns, workshops, and better infrastructure.

12.
Cytokine ; 170: 156347, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37639845

RESUMO

Liver cirrhosis develops as a result of persistent inflammation and liver injury. The prolonged inflammation triggers the buildup of fibrous tissue and regenerative nodules within the liver, leading to the distortion of the hepatic vascular structure and impaired liver function. Cirrhosis disrupts the ability of liver function to maintain homeostasis and hepatic immunosurveillance which causes immunological dysfunction in the body. In pathological conditions, the production of cytokines in the liver is carefully regulated by various cells in response to tissue stimulation. Cytokines and inflammasomes are the key regulators and systematically contribute to the development of cirrhosis which involves an inflammatory response. However, the crosstalk role of different cytokines in the cirrhosis progression is poorly understood. Tumour necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), interleukin-6 (IL-6), and interferon-gamma (IFN-γ), among others, are proinflammatory cytokines that contribute to liver cell necrosis, which in turn causes the development of fibrosis. While IL-10 exhibits a potent anti-inflammatory effect on the liver by inhibiting immune cell activation and neutralizing pro-inflammatory cytokine activity. Inflammasomes have also been implicated in the profibrotic processes of liver cirrhosis, as well as the production of chemokines such as CCL2/MCP-1. It is evident that inflammasomes have a role in the proinflammatory response seen in chronic liver illnesses. In conclusion, cirrhosis significantly impacts the immune system, leading to immunological dysfunction and alterations in both innate and acquired immunity. Proinflammatory cytokines like TNF-α, IL-1ß, IL-6, and IFNγ are upregulated in cirrhosis, contributing to liver cell necrosis and fibrosis development. Managing cytokine-mediated inflammation and fibrosis is a key therapeutic approach to alleviate portal hypertension and its associated liver complications. This review attempted to focus largely on the role of immune dysfunction mediated by different cytokines and inflammasomes involved in the progression, regulation and development of liver cirrhosis.


Assuntos
Citocinas , Doenças do Sistema Imunitário , Humanos , Inflamassomos , Interleucina-6 , Fator de Necrose Tumoral alfa , Cirrose Hepática , Interferon gama , Inflamação , Necrose
13.
J Org Chem ; 88(19): 13475-13489, 2023 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-37712568

RESUMO

Dioxobimanes, colloquially known as bimanes, are a well-established family of N-heterobicyclic compounds that share a characteristic core structure, 1,5-diazabicyclo[3.3.0]octadienedione, bearing two endocyclic carbonyl groups. By sequentially thionating these carbonyls in the syn and anti isomers of the known (Me,Me)dioxobimane, we were able to synthesize a series of thioxobimanes, representing the first heavy-chalcogenide bimane variants. These new compounds were extensively characterized spectroscopically and crystallographically, and their aromaticity was probed computationally. Their potential role as ligands for transition metals was demonstrated by synthesizing a representative gold(I)-thioxobimane complex.

14.
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.

15.
Phys Chem Chem Phys ; 25(36): 24613-24624, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37665020

RESUMO

In the modern era, realizing highly efficient supercapacitors (SCs) derived through green routes is paramount to reducing environmental impact. This study demonstrates ways to recycle and reuse used waste dry cell anodes to synthesize nanohybrid electrodes for SCs. Instead of contributing to landfill and the emission of toxic gas to the environment, dry cells are collected and converted into a resource for improved SC cells. The high performance of the electrode was achieved by exploiting battery-type polyoxometalate (POM) clusters infused on a reduced graphene oxide (rGO) surface. Polyoxometalate (K5[α-SiMo2VW9O40]) assisted in the precise bottom-up reduction of graphene oxide (GO) under UV irradiation at room temperature to produce vanadosilicate embedded photo-reduced graphene oxide (prGO-Mo2VW9O40). Additionally, a chemical reduction route for GO (crGO) was trialed to relate to the prGO, followed by the integration of a faradaic monolayer (crGO-Mo2VW9O40). Both composite frameworks exhibit unique hierarchical heterostructures that offer synergic effects between the dual components. As a result, the hybrid material's ion transport kinetics and electrical conductivity enhance the critical electrochemical process at the electrode's interface. The simple co-participation method delivers a remarkable specific capacity (capacitance) of 405 mA h g-1 (1622 F g-1) and 117 mA h g-1 (470 F g-1) for prGO-Mo2VW9O40 and crGO-Mo2VW9O40 nanocomposites alongside high capacitance retentions of 94.5% and 82%, respectively, at a current density of 0.3 A g-1. Furthermore, the asymmetric electrochromic supercapacitor crGO//crGO-Mo2VW9O40 was designed, manifesting a broad operating potential (1.2 V). Finally, the asymmetric electrode material resulted in an enhanced specific capacity, energy, and power of 276.8 C g-1, 46.16 W h kg-1, and 1195 W kg-1, respectively, at a current density of 0.5 A g-1. The electrode materials were tested in the operating of a DC motor.

16.
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
17.
Chem Soc Rev ; 51(13): 5557-5605, 2022 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-35704949

RESUMO

With the serendipitous discovery of crown ethers by Pedersen more than half a century ago and the subsequent introduction of host-guest chemistry and supramolecular chemistry by Cram and Lehn, respectively, followed by the design and synthesis of wholly synthetic cyclophanes-in particular, fluorescent cyclophanes, having rich structural characteristics and functions-have been the focus of considerable research activity during the past few decades. Cyclophanes with remarkable emissive properties have been investigated continuously over the years and employed in numerous applications across the field of science and technology. In this Review, we feature the recent developments in the chemistry of fluorescent cyclophanes, along with their design and synthesis. Their host-guest chemistry and applications related to their structure and properties are highlighted.

18.
J Am Chem Soc ; 144(37): 16841-16854, 2022 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-36083184

RESUMO

Polar and polarizable π-conjugated organic molecules containing push-pull chromophores have been investigated extensively in the past. Identifying unique backbones and building blocks for fluorescent dyes is a timely exercise. Here, we report the synthesis and characterization of a series of fluorescent dyes containing quadrupolar A-D-A constitutions (where A = acceptor and D = donor), which exhibit fluorescence emission at a variety of different wavelengths. We have investigated the effects of different electron-withdrawing groups, located at both termini of a para-terphenylene backbone, by steady-state UV/vis and fluorescence spectroscopy. Pyridine and substituted pyridinium units are also introduced during the construction of the quadrupolar backbones. Depending on the quadrupolarity, fluorescence emission wavelengths cover from 380 to 557 nm. Time-resolved absorption and emission spectroscopy reveal that the photophysical properties of those quadrupolar dyes result from intramolecular charge transfer. One of the dyes we have investigated is a symmetrical box-like tetracationic cyclophane. Its water-soluble tetrachloride, which is non-cytotoxic to cells up to a loading concentration of 1 µM, has been employed in live-cell imaging. When taken up by cells, the tetrachloride emits a green fluorescence emission without any hint of photobleaching or disruption of normal cell behavior. We envision that our design strategy of modifying molecules through the functionalization of the quadrupolar building blocks as chromophores will lead to future generations of fluorescent dyes in which these A-D-A constitutional fragments are incorporated into more complex molecules and polymers for broader photophysical and biological applications.


Assuntos
Corantes Fluorescentes , Piridinas , Álcoois , Corantes Fluorescentes/química , Polímeros , Água
19.
EMBO Rep ; 21(3): e48692, 2020 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-32072744

RESUMO

Dysregulation of lipid homeostasis is intimately associated with defects in insulin secretion, a key feature of type 2 diabetes. Here, we explore the role of the putative lipid transporter ABCA12 in regulating insulin secretion from ß-cells. Mice with ß-cell-specific deletion of Abca12 display impaired glucose-stimulated insulin secretion and eventual islet inflammation and ß-cell death. ABCA12's action in the pancreas is independent of changes in the abundance of two other cholesterol transporters, ABCA1 and ABCG1, or of changes in cellular cholesterol or ceramide content. Instead, loss of ABCA12 results in defects in the genesis and fusion of insulin secretory granules and increases in the abundance of lipid rafts at the cell membrane. These changes are associated with dysregulation of the small GTPase CDC42 and with decreased actin polymerisation. Our findings establish a new, pleiotropic role for ABCA12 in regulating pancreatic lipid homeostasis and insulin secretion.


Assuntos
Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Transportador 1 de Cassete de Ligação de ATP/genética , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Insulina/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/metabolismo , Camundongos
20.
Phys Chem Chem Phys ; 24(35): 20941-20952, 2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36053209

RESUMO

A new ratiometric fluorescent probe (E)-2-(benzo[d]thiazol-2-yl)-3-(8-methoxyquinolin-2-yl)acrylonitrile (HQCN) was synthesised by the perfect blending of quinoline and a 2-benzothiazoleacetonitrile unit. In a mixed aqueous solution, HQCN reacts with hydrazine (N2H4) to give a new product 2-(hydrazonomethyl)-8-methoxyquinoline along with the liberation of the 2-benzothiazoleacetonitrile moiety. In contrast, the reaction of hypochlorite ions (OCl-) with the probe gives 8-methoxyquinoline-2-carbaldehyde. In both cases, the chemodosimetric approaches of hydrazine and hypochlorite selectively occur at the olefinic carbon but give two different products with two different outputs, as observed from the fluorescence study exhibiting signals at 455 nm and 500 nm for hydrazine and hypochlorite, respectively. A UV-vis spectroscopy study also depicts a distinct change in the spectrum of HQCN in the presence of hydrazine and hypochlorite. The hydrazinolysis of HQCN exhibits a prominent chromogenic as well as ratiometric fluorescence change with a 165 nm left-shift in the fluorescence spectrum. Similarly, the probe in hand (HQCN) can selectively detect hypochlorite in a ratiometric manner with a shift of 120 nm, as observed from the fluorescence emission spectra. HQCN can detect hydrazine and OCl- as low as 2.25 × 10-8 M and 3.46 × 10-8 M, respectively, as evaluated from the fluorescence experiments again. The excited state behaviour of the probe HQCN and the chemodosimetric products with hydrazine and hypochlorite are studied by the nanosecond time-resolved fluorescence technique. Computational studies (DFT and TDDFT) with the probe and the hydrazine and hypochlorite products were also performed. The observations made in the fluorescence imaging studies with human blood cells manifest that HQCN can be employed to monitor hydrazine and OCl- in human peripheral blood mononuclear cells (PBMCs). It is indeed a rare case that the single probe HQCN is found to be successfully able to detect hydrazine and hypochlorite in PBMCs, with two different outputs.


Assuntos
Ácido Hipocloroso , Leucócitos Mononucleares , Corantes Fluorescentes/química , Humanos , Hidrazinas , Ácido Hipocloroso/química , Espectrometria de Fluorescência
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