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1.
Small ; 17(52): e2102903, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34418304

RESUMO

Surface/interfacial engineering is an essential technique to explore the fiber materials properties and fulfil new functionalities. An extensive scope of current physical and chemical treating methods is reviewed here together with a variety of real-world applications. Moreover, a new surface/interface engineering approach is also introduced: self-assembly via π-π stacking, which has great potential for the surface modification of fiber materials due to its nondestructive working principle. A new fiber family member, metal-oxide framework (MOF) fiber shows promising candidacy for fiber based wearable electronics. The understanding of surface/interfacial engineering techniques on fiber materials is advanced here and it is expected to guide the rational design of future fiber based wearable electronics.


Assuntos
Dispositivos Eletrônicos Vestíveis , Eletrônica
2.
Int J Mol Sci ; 21(6)2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-32204355

RESUMO

Kisspeptin-expressing neurons in the anteroventral periventricular nucleus (AVPV) and the arcuate nucleus (ARC) of the hypothalamus relay hormonal and metabolic information to gonadotropin-releasing hormone neurons, which in turn regulate pituitary and gonadal function. Phosphatase and tensin homolog (PTEN) blocks phosphatidylinositol 3-kinase (PI3K), a signaling pathway utilized by peripheral factors to transmit their signals. However, whether PTEN signaling in kisspeptin neurons helps to integrate peripheral hormonal cues to regulate gonadotropin release is unknown. To address this question, we generated mice with a kisspeptin cell-specific deletion of Pten (Kiss-PTEN KO), and first assessed kisspeptin protein expression and gonadotropin release in these animals. Kiss-PTEN KO mice displayed a profound sex and region-specific kisspeptin neuron hyperthrophy. We detected both kisspeptin neuron hyperthrophy as well as increased kisspeptin fiber densities in the AVPV and ARC of Kiss-PTEN KO females and in the ARC of Kiss-PTEN KO males. Moreover, Kiss-PTEN KO mice showed a reduced gonadotropin release in response to gonadectomy. We also found a hyperactivation of mTOR, a downstream PI3K target and central regulator of cell metabolism, in the AVPV and ARC of Kiss-PTEN KO females but not males. Fasting, known to inhibit hypothalamic kisspeptin expression and luteinizing hormone levels, failed to induce these changes in Kiss-PTEN KO females. We conclude that PTEN signaling regulates kisspeptin protein synthesis in both sexes and that its role as a metabolic signaling molecule in kisspeptin neurons is sex-specific.


Assuntos
Núcleo Arqueado do Hipotálamo/metabolismo , Gonadotropinas/metabolismo , Hipotálamo/metabolismo , Kisspeptinas/genética , PTEN Fosfo-Hidrolase/genética , Animais , Feminino , Marcação de Genes/métodos , Hormônio Liberador de Gonadotropina/metabolismo , Humanos , Kisspeptinas/metabolismo , Hormônio Luteinizante/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fatores Sexuais , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo
3.
FASEB J ; 32(8): 4270-4283, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29533737

RESUMO

Bcr-Abl (break-point cluster region-abelson), the oncogenic trigger of chronic myelogenous leukemia (CML), has previously been shown to up-regulate the expression and activity of sphingomyelin synthase 1 (SMS1), which contributes to the proliferation of CML cells; however, the mechanism by which this increased expression of SMS1 is mediated remains unknown. In the current study, we show that Bcr-Abl enhances the expression of SMS1 via a 30-fold up-regulation of its transcription. Of most interest, the Bcr-Abl-regulated transcription of SMS1 is initiated from a novel transcription start site (TSS) that is just upstream of the open reading frame. This shift in TSS utilization generates an SMS1 mRNA with a substantially shorter 5' UTR compared with its canonical mRNA. This shorter 5' UTR imparts a 20-fold greater translational efficiency to SMS1 mRNA, which further contributes to the increase of its expression in CML cells. Therefore, our study demonstrates that Bcr-Abl increases SMS1 protein levels via 2 concerted mechanisms: up-regulation of transcription and enhanced translation as a result of the shift in TSS utilization. Remarkably, this is the first time that an oncogene-Bcr-Abl-has been demonstrated to drive such a mechanism that up-regulates the expression of a functionally important target gene, SMS1.-Moorthi, S., Burns, T. A., Yu, G.-Q., Luberto, C. Bcr-Abl regulation of sphingomyelin synthase 1 reveals a novel oncogenic-driven mechanism of protein up-regulation.


Assuntos
Carcinogênese/genética , Proteínas de Fusão bcr-abl/genética , Proteínas de Membrana/genética , Proteínas do Tecido Nervoso/genética , Transferases (Outros Grupos de Fosfato Substituídos)/genética , Regulação para Cima/genética , Regiões 5' não Traduzidas/genética , Linhagem Celular Tumoral , Células HL-60 , Células HeLa , Humanos , Células K562 , Fases de Leitura Aberta/genética , RNA Mensageiro/genética , Sítio de Iniciação de Transcrição/fisiologia , Transcrição Gênica/genética
4.
Am J Physiol Endocrinol Metab ; 307(11): E969-82, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-25269483

RESUMO

Hypothalamic kisspeptin neurons integrate and translate cues from the internal and external environments that regulate gonadotropin-releasing hormone (GnRH) secretion and maintain fertility in mammals. However, the intracellular signaling pathways utilized to translate such information into changes in kisspeptin expression, release, and ultimately activation of the kisspeptin-receptive GnRH network have not yet been identified. PI3K is an important signaling node common to many peripheral factors known to regulate kisspeptin expression and GnRH release. We investigated whether PI3K signaling regulates hypothalamic kisspeptin expression, pubertal development, and adult fertility in mice. We generated mice with a kisspeptin cell-specific deletion of the PI3K catalytic subunits p110α and p110ß (kiss-p110α/ß-KO). Using in situ hybridization, we examined Kiss1 mRNA expression in gonad-intact, gonadectomized (Gdx), and Gdx + steroid-replaced mice. Kiss1 cell number in the anteroventral periventricular hypothalamus (AVPV) was significantly reduced in intact females but not in males. In contrast, compared with WT and regardless of steroid hormone status, Kiss1 cell number was lower in the arcuate (ARC) of kiss-p110α/ß-KO males, but it was unaffected in females. Both intact Kiss-p110α/ß-KO males and females had reduced ARC kisspeptin-immunoreactive (IR) fibers compared with WT animals. Adult kiss-p110α/ß-KO males had significantly lower circulating luteinizing hormone (LH) levels, whereas pubertal development and fertility were unaffected in males. Kiss-p110α/ß-KO females exhibited a reduction in fertility despite normal pubertal development, LH levels, and estrous cyclicity. Our data show that PI3K signaling is important for the regulation of hypothalamic kisspeptin expression and contributes to normal fertility in females.


Assuntos
Fertilidade/fisiologia , Hipotálamo/metabolismo , Kisspeptinas/fisiologia , Fosfatidilinositol 3-Quinases/fisiologia , Transdução de Sinais/fisiologia , Animais , Estradiol/metabolismo , Ciclo Estral/genética , Ciclo Estral/fisiologia , Feminino , Glucose/metabolismo , Kisspeptinas/biossíntese , Hormônio Luteinizante/biossíntese , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
5.
J Org Chem ; 79(21): 10605-10, 2014 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-25322279

RESUMO

A direct method has been developed for iodine-mediated thiolation of naphthols/naphthylamines and arylsulfonyl hydrazides through the formation of C-S bond and cleavage of S-N/S-O bonds. In this transformation, a range of valuable thioethers are easily achieved in moderate to good yields.


Assuntos
1-Naftilamina/química , Iodo/química , Naftóis/química , Compostos de Sulfidrila/química , Sulfetos/síntese química , Catálise , Ligação de Hidrogênio , Estrutura Molecular , Sulfetos/química
6.
FEBS Lett ; 594(22): 3751-3764, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33037626

RESUMO

Bcr-abl1 oncogene causes a shift in the transcription start site of the SMS1 gene (SGMS1) encoding the sphingomyelin (SM) synthesizing enzyme, sphingomyelin synthase 1 (SMS1). This results in an mRNA with a significantly shorter 5'-UTR, called 7-SGMS1, which is translated more efficiently than another transcript (IIb-SGMS1) with a longer 5'UTR in Bcr-abl1-positive cells. Here, we determine the effects of these alternative 5'UTRs on SMS1 translation and investigate the key features underlying such regulation. First, the presence of the longer IIb 5'UTR is sufficient to greatly impair translation of a reporter gene. Deletion of the upstream open reading frame (-164 nt) or of the predicted stem-loops in the 5'UTR of IIb-SGMS1 has minimal effects on SGMS1 translation. Conversely, deletion of nucleotides -310 to -132 enhanced transcription of IIb-SGMS1 to reach that of 7-SGMS1. We thus suggest that regulatory features within nucleotides -310 and -132 modulate IIb-SGMS1 translation efficiency.


Assuntos
Proteínas de Fusão bcr-abl/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Transferases (Outros Grupos de Fosfato Substituídos)/genética , Transferases (Outros Grupos de Fosfato Substituídos)/metabolismo , Regiões 5' não Traduzidas , Regulação Neoplásica da Expressão Gênica , Células HeLa , Humanos , Conformação de Ácido Nucleico , Biossíntese de Proteínas , RNA Mensageiro/química , Sítio de Iniciação de Transcrição
7.
J Colloid Interface Sci ; 533: 259-267, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30170277

RESUMO

Use of renewable raw materials for fabrication catalysts with excellent catalytic performance is of considerable importance for sustainable chemistry. Here, biowaste soybean curd residue (SCR) was used to prepare porous N-doped carbon materials (PNCM) via the carbonization method, and subsequently modified with small Pd nanoparticles (NPs) to generate the Pd/PNCM catalyst. Pd/PNCM was used for catalytic hydrogenation of phenol to cyclohexanone, as the latter is an important chemical intermediate that is usually produced under harsh reaction conditions. The Pd/PNCM catalyst can hydrogenate phenol to cyclohexanone in aqueous solution under mild reaction conditions with excellent catalytic performance. In addition, compared to commercial Pd/C, Pd/PNCM exhibits excellent catalytic performance and stability, which is attributed to the synergetic effects of N-doping of porous carbon supports and stabilization of ultra-small Pd NPs. Thus, this study highlights a new pathway for preparing N-doped porous carbon materials using biomass waste as the precursor material, and subsequently fabricating precious metal-modified catalysts with excellent catalytic performance for sustainable and green catalysis.


Assuntos
Carbono/química , Nitrogênio/química , Paládio/química , Fenóis/química , Alimentos de Soja , Resíduos , Biomassa , Catálise , Cicloexanonas/síntese química , Cicloexanonas/química , Hidrogenação , Tamanho da Partícula , Porosidade , Propriedades de Superfície
8.
Nanoscale ; 10(45): 21466-21474, 2018 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-30427014

RESUMO

The fabrication of stable porous organic polymers (POPs) with heteroatoms that can firmly anchor noble metal nanoparticles (NPs) is a challenging and significant task for heterogeneous catalysis. In the current work, we used piperazine and cyanuric chloride as precursors and successfully fabricated a PC-POP material. Then, through the impregnation method and subsequently the reduction method, ultrafine Pt NPs were confined in the PC-POP with a high dispersion. The Pt NP active sites are accessible due to the uniform mesopores of the PC-POP that facilitate diffusion and mass transfer. The organic cages and nitrogen atoms in the PC-POP frameworks can make the Pt NPs stably anchored in the PC-POP during the catalytic process. The obtained Pt@PC-POP nanocatalyst showed excellent catalytic activity and good recyclability in the selective hydrogenation of halogenated nitrobenzenes and catalytic hydrolysis of ammonia borane as compared with many other reported noble metal catalysts.

9.
J Colloid Interface Sci ; 506: 524-531, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-28756319

RESUMO

Novel fluffy smoke like mesoporous N-doped carbon (mNC) was prepared through a facile one-pot carbonization method using the low-cost melamine and polyacrylonitrile as the precursor materials. The obtained mNC material exhibits a high surface area, rich nitrogen content and can be used as an ideal catalyst support to fabricate noble metal modified nanocatalysts. Here, small Ag nanoparticles were supported on the mNC material with high dispersion to give the Ag/mNC nanocatalyst. The obtained Ag/mNC nanocatalyst was used in the catalytic reduction of nitroarenes and showed excellent catalytic activity, probably due to the small Ag NPs which highly dispersed on the fluffy mNC material that can enhance the accessibility and mass transfer, and subsequently enhance the catalytic activity. It is worth mentioning that, in the catalytic reduction of nitroarenes with halogenated groups, almost no dehalogenation phenomenon can be observed, which implies the superior catalytic chemoselectivity of the Ag/mNC nanocatalyst.

10.
Chem Commun (Camb) ; 53(84): 11572-11575, 2017 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-28990598

RESUMO

A straightforward Fe-catalyzed method for the synthesis of pyrrolo[1,2-a]quinoxalines from 1-(2-aminophenyl)pyrroles and cyclic ethers, which includes functionalization of C(sp3)-H bonds and the construction of C-C and C-N bonds, has been developed. The features of this reaction are Fe catalysis, low-cost and readily accessible starting materials. Moreover, this procedure exhibits good functional group tolerance and a series of pyrrolo[1,2-a]quinoxaline derivatives are obtained in moderate to good yields.

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