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1.
Mol Cell ; 73(4): 788-802.e7, 2019 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-30704899

RESUMO

mTORC1 and GSK3 play critical roles in early stages of (macro)autophagy, but how they regulate late steps of autophagy remains poorly understood. Here we show that mTORC1 and GSK3-TIP60 signaling converge to modulate autophagosome maturation through Pacer, an autophagy regulator that was identified in our recent study. Hepatocyte-specific Pacer knockout in mice results in impaired autophagy flux, glycogen and lipid accumulation, and liver fibrosis. Under nutrient-rich conditions, mTORC1 phosphorylates Pacer at serine157 to disrupt the association of Pacer with Stx17 and the HOPS complex and thus abolishes Pacer-mediated autophagosome maturation. Importantly, dephosphorylation of Pacer under nutrient-deprived conditions promotes TIP60-mediated Pacer acetylation, which facilitates HOPS complex recruitment and is required for autophagosome maturation and lipid droplet clearance. This work not only identifies Pacer as a regulator in hepatic autophagy and liver homeostasis in vivo but also reveals a signal integration mechanism involved in late stages of autophagy and lipid metabolism.


Assuntos
Autofagossomos/enzimologia , Proteínas Relacionadas à Autofagia/metabolismo , Autofagia , Quinase 3 da Glicogênio Sintase/metabolismo , Metabolismo dos Lipídeos , Fígado/enzimologia , Lisina Acetiltransferase 5/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas de Ligação a Fosfato/metabolismo , Transativadores/metabolismo , Acetilação , Animais , Autofagossomos/patologia , Proteínas Relacionadas à Autofagia/genética , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Quinase 3 da Glicogênio Sintase/genética , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Gotículas Lipídicas/metabolismo , Fígado/patologia , Lisina Acetiltransferase 5/genética , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Proteínas de Membrana , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/enzimologia , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/patologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas de Ligação a Fosfato/genética , Fosforilação , Processamento de Proteína Pós-Traducional , Proteínas Qa-SNARE/genética , Proteínas Qa-SNARE/metabolismo , Transdução de Sinais , Transativadores/genética , Proteínas Supressoras de Tumor
2.
Mol Cell ; 65(6): 1029-1043.e5, 2017 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-28306502

RESUMO

Class III PI3-kinase (PI3KC3) is essential for autophagy initiation, but whether PI3KC3 participates in other steps of autophagy remains unknown. The HOPS complex mediates the fusion of intracellular vesicles to lysosome, but how HOPS specifically tethers autophagosome to lysosome remains elusive. Here, we report Pacer (protein associated with UVRAG as autophagy enhancer) as a regulator of autophagy. Pacer localizes to autophagic structures and positively regulates autophagosome maturation. Mechanistically, Pacer antagonizes Rubicon to stimulate Vps34 kinase activity. Next, Pacer recruits PI3KC3 and HOPS complexes to the autophagosome for their site-specific activation by anchoring to the autophagosomal SNARE Stx17. Furthermore, Pacer is crucial for the degradation of hepatic lipid droplets, the suppression of Salmonella infection, and the clearance of protein aggregates. These results not only identify Pacer as a crucial multifunctional enhancer in autophagy but also uncover both the involvement of PI3KC3 and the mediators of HOPS's specific tethering activity in autophagosome maturation.


Assuntos
Autofagossomos/enzimologia , Proteínas Relacionadas à Autofagia/metabolismo , Autofagia , Classe III de Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Qa-SNARE/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Proteínas Relacionadas à Autofagia/genética , Endossomos/enzimologia , Ativação Enzimática , Células HEK293 , Células HeLa , Células Hep G2 , Hepatócitos/enzimologia , Interações Hospedeiro-Patógeno , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Gotículas Lipídicas/metabolismo , Lisossomos/enzimologia , Fusão de Membrana , Agregados Proteicos , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas Qa-SNARE/genética , Interferência de RNA , Salmonella typhimurium/crescimento & desenvolvimento , Transdução de Sinais , Fatores de Tempo , Transfecção , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Proteínas de Transporte Vesicular/genética
3.
Reprod Domest Anim ; 59(9): e14632, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39279335

RESUMO

Handmade cloning (HMC) has a higher yield and is relatively less difficult to operate compared to traditional micromanipulation cloning. Yet, there are few reports on handmade cloning in sheep. Therefore, this study investigates the key nodes such as AC and DC voltage, denucleation method and fusion method in sheep handmade cloning. In addition, it compares the effects of fibroblasts (FC) and umbilical cord mesenchymal stem cells (UC-MSCs) of different states as donors on the development of HMC embryos. Furthermore, the effect of different freezing solutions on the survival rate of frozen blastocysts without zona pellucida was also investigated. The results indicate that an AC voltage of 150 V/cm and a DC voltage of 1800 V/cm significantly enhanced the fusion and blastocyst rates (p < .01). The blastocyst rate achieved with umbilical cord MSCs as nucleus donors was significantly higher (40.3%) than that achieved with fibroblasts and differentiated umbilical cord MSCs (21.5%, 22.5%) (p < .01). The highest survival rate was achieved using 20% DMSO + 20% EG for freezing without zona pellucida. In conclusion, the most efficient and pregnant ovine HMC cloning method using 150 V/cm AC, 1800 V/cm DC, knife-cut denucleation, two-step fusion and the use of UC-MSCs as nucleus donors resulted in the highest overall efficiency and pregnancy after transplantation.


Assuntos
Blastocisto , Clonagem de Organismos , Fibroblastos , Células-Tronco Mesenquimais , Técnicas de Transferência Nuclear , Cordão Umbilical , Animais , Cordão Umbilical/citologia , Clonagem de Organismos/veterinária , Clonagem de Organismos/métodos , Feminino , Gravidez , Técnicas de Transferência Nuclear/veterinária , Ovinos , Núcleo Celular , Criopreservação/veterinária , Criopreservação/métodos , Carneiro Doméstico , Técnicas de Cultura Embrionária/veterinária
4.
Sensors (Basel) ; 20(1)2019 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-31878254

RESUMO

It very important to be able to efficiently detect hydrazine hydrate in an aqueous medium due to its high toxicity. Here, we have proposed a new idea: to construct a sensor for the rapid determination of hydrazine hydrate based on the nano-CuO derived by controlled pyrolysis of HKUST-1 [Cu3(BTC)2(H2O)3]. The as-prepared CuO at 400 °C possesses a uniform appearance with nano-structure via SEM images, and the nano-CuO-400 has exhibited excellent electrocatalytic activity towards hydrazine oxidation. Amperometric i-t curves shows the peak current as linearly proportional to the hydrazine concentration within 1.98-169.3 µmol L-1 and 232-2096 µmol L-1 with the detection limit of 2.55 × 10-8 mol L-1 and 7.01 × 10-8 mol L-1, respectively. Moreover, the sensor constructed in the experiment shows good selectivities, and it is feasible to determining actual water samples.

5.
Inorg Chem ; 55(1): 292-9, 2016 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-26653758

RESUMO

Microporous metal organic frameworks (MOFs) show promising application in several fields, but they often suffer from the weak robustness and stability after the removal of guest molecules. Here, three isostructural cationic metal-organic frameworks {[(Cu4Cl)(cpt)4(H2O)4]·3X·4DMAc·CH3OH·5H2O} (FJU-14, X = NO3, ClO4, BF4; DMAc = N,N'-dimethylacetamide) containing two types of polyhedral nanocages, one octahedron, and another tetrahedron have been synthesized from bifunctional organic ligands 4-(4H-1,2,4-triazol-4-yl) benzoic acid (Hcpt) and various copper salts. The series of MOFs FJU-14 are demonstrated as the first examples of the isostructural MOFs whose robustness, thermal stability, and CO2 capacity can be greatly improved via rational modulation of counteranions in the tetrahedral cages. The activated FJU-14-BF4-a containing BF4(-) anion can take CO2 of 95.8 cm(3) cm(-3) at ambient conditions with an adsorption enthalpy only of 18.8 kJ mol(-1). The trapped CO2 density of 0.955 g cm(-3) is the highest value among the reported MOFs. Dynamic fixed bed breakthrough experiments indicate that the separation of CO2/N2 mixture gases through a column packed with FJU-14-BF4-a solid can be efficiently achieved. The improved robustness and thermal stability for FJU-14-BF4-a can be attributed to the balanced multiple hydrogen-bonding interactions (MHBIs) between the BF4(-) counteranion and the cationic skeleton, while the high-density and low-enthalpy CO2 capture on FJU-14-BF4-a can be assigned to the multiple-point interactions between the adsorbate molecules and the framework as well as with its counteranions, as proved by single-crystal structures of the guest-free and CO2-loaded FJU-14-BF4-a samples.

6.
Inorg Chem ; 55(2): 983-6, 2016 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-26731165

RESUMO

Three isostructural imidazole-cation-templated metal phosphates (FJU-25) are the first examples to demonstrate that the tuning of metal cation nodes can be an efficient strategy to significantly improve the proton conductivity without changing the structure of the proton-conducting pathway.

7.
J Am Chem Soc ; 137(2): 913-8, 2015 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-25551516

RESUMO

On-board fuel cell technology requires proton conducting materials with high conductivity not only at intermediate temperatures for work but also at room temperature and even at subzero temperature for startup when exposed to the colder climate. To develop such materials is still challenging because many promising candidates for the proton transport on the basis of extended microstructures of water molecules suffer from significant damage by heat at temperatures above 80 °C or by freeze below -5 °C. Here we show imidazole loaded tetrahedral polyimides with mesopores and good stability (Im@Td-PNDI 1 and Im@Td-PPI 2) exhibiting a high anhydrous proton conductivity over a wide temperature range from -40 to 90 °C. Among all anhydrous proton conductors, the conductivity of 2 is the highest at temperatures below 40 °C and comparable with the best materials, His@[Al(OH)(1,4-ndc)]n and [Zn3(H2PO4)6(H2O)3](Hbim), above 40 °C.

8.
Heliyon ; 10(5): e27034, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38463854

RESUMO

Tuberculosis (TB) is an important public health problem, and the One Health approach is essential for controlling zoonotic tuberculosis. Therefore, a rationally designed and more effective TB vaccine is urgently needed. To enhance vaccine efficacy, it is important to design vaccine candidates that stimulate both cellular and humoral immunity against TB. In this study, we fused the secreted protein Ag85A as the T cell antigen with truncated forms of the mycobacterial cell wall protein PstS1 with B cell epitopes to generate vaccine candidates, Ag85A-tnPstS1 (AP1, AP2, and AP3), and tested their immunogenicity and protective efficacy in mice. The three vaccine candidates induced a significant increase in the levels of T cell-related cytokines such as IFN-γ and IL-17, and AP1 and AP2 can induce more balanced Th1/Th2 responses than AP3. Strong humoral immune responses were also observed in which the production of IgG antibodies including its subclasses IgG1, IgG2c, and IgG3 was tremendously stimulated. AP1 and AP2 induced early antibody responses and more IgG3 isotype antibodies than AP3. Importantly, the mice immunised with the subunit vaccine candidates, particularly AP1 and AP2, had lower bacterial burdens than the control mice. Moreover, the serum from immunised mice can enhance phagocytosis and phagosome-lysosome fusion in macrophages, which can help to eradicate intracellular bacteria. These results indicate that the subunit vaccines Ag85A-tnPstS1 can be promising vaccine candidates for tuberculosis prevention.

9.
Animals (Basel) ; 14(4)2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38396557

RESUMO

Oocytes are efficient at reprogramming terminally differentiated cells to a totipotent state. Nuclear transfer techniques can exploit this property to produce cloned animals. However, the overall efficiency is low. The use of umbilical cord mesenchymal stem cells (UC-MSCs) as donor nuclei may increase blastocyst rates, but the exact reasons for this remain unexplored. A single-cell transcriptomic approach was used to map the transcriptome profiles of eight-cell embryos that were in vitro-fertilized and handmade-cloned using umbilical cord mesenchymal stem cells and fibroblasts as nuclear donors. Differences were examined at the chromatin level, the level of differentially expressed genes, the level of histone modifications and the level of DNA methylation. This research provides critical information regarding the use of UC-MSCs as a preferred donor nucleus for nuclear transfer techniques. It also offers unique insights into the mechanism of cellular reprogramming.

10.
Plant Mol Biol ; 83(1-2): 77-87, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23512102

RESUMO

Setaria viridis is an emerging model species for genetic studies of C4 photosynthesis. Many basic molecular resources need to be developed to support for this species. In this paper, we performed a comprehensive transcriptome analysis from multiple developmental stages and tissues of S. viridis using next-generation sequencing technologies. Sequencing of the transcriptome from multiple tissues across three developmental stages (seed germination, vegetative growth, and reproduction) yielded a total of 71 million single end 100 bp long reads. Reference-based assembly using Setaria italica genome as a reference generated 42,754 transcripts. De novo assembly generated 60,751 transcripts. In addition, 9,576 and 7,056 potential simple sequence repeats (SSRs) covering S. viridis genome were identified when using the reference based assembled transcripts and the de novo assembled transcripts, respectively. This identified transcripts and SSR provided by this study can be used for both reverse and forward genetic studies based on S. viridis.


Assuntos
Perfilação da Expressão Gênica/métodos , Genoma de Planta , Fotossíntese , RNA de Plantas/metabolismo , Setaria (Planta)/metabolismo , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Cromossomos de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Germinação , Repetições de Microssatélites , Modelos Moleculares , Anotação de Sequência Molecular , Família Multigênica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA de Plantas/genética , Reprodução , Sementes/genética , Sementes/metabolismo , Setaria (Planta)/genética , Setaria (Planta)/crescimento & desenvolvimento , Transcriptoma
11.
Genomics Proteomics Bioinformatics ; 20(2): 322-333, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35093602

RESUMO

A comprehensive profiling of the vaginal microbial communities and their variability enables an accurate description of the microbiome in women. However, there is a lack of studies available on Chinese women. In the present study, the composition of the vaginal microbiota during pregnancy and the 6-week postpartum period of 454 Chinese women was characterized by sequencing the V3-V4 region of the 16S ribosomal RNA (rRNA) gene. The vaginal microbiome showed variations during pregnancy and the postpartum period based on the abortion history, hypertensive disorders, delivery mode, and maternal age. Co-variation of 22 bacterial taxa, including the Lactobacillus genus and two of its species, may account for the common characteristics of the vaginal microbiome under scenarios of different medical histories and pregnancy outcomes. In contrast, discriminant bacterial species were significantly different between women who had preterm birth (PTB) with and without premature rupture of membranes (PROM), and the community state type (CST) IV-A without any predominant Lactobacillus species in the microbiota was more prevalent during pregnancy in the PROM-PTB cases, suggesting that specific bacterial species could be considered to distinguish between different types of PTB. By providing data on Chinese women, this study will enrich the knowledge of the human microbiome and contribute to a better understanding of the association between the vaginal microbiome and reproductive health.


Assuntos
Microbiota , Nascimento Prematuro , Humanos , Recém-Nascido , Gravidez , Feminino , Nascimento Prematuro/microbiologia , Vagina/microbiologia , Microbiota/genética , RNA Ribossômico 16S/genética , Lactobacillus/genética , Bactérias/genética , China/epidemiologia
12.
Mitochondrial DNA B Resour ; 6(7): 1829-1831, 2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34124358

RESUMO

Syringa reticulata subsp. amurensis (Rupr.) P. S. Green & M. C. Chang (Oleaceae) is a shrub or tree with high medicinal value as well as great ecological significance as an urban garden plant. To better understand the molecular genetics and evolutionary of S. reticulata subsp. amurensis, its complete chloroplast genome was sequenced and annotated. The assembled chloroplast genome is a circular 156,141 bp sequence, consisting of 87,108 bp large single copy (LSC) region and 17,239 bp small single copy (SSC) region, which were flanked by a pair of 25,897 bp inverted repeats (IRs). The GC content of the chloroplast genome is 36.14%. Moreover, a total of 132 functional genes were annotated, including 88 protein-coding, 36 tRNA, and eight rRNA genes. Phylogenetic analysis showed that S. reticulata subsp. amurensis was most closely related to S. reticulata subsp. Pekinensis and the genus Syringa is paraphyletic group. This study provides important information for further phylogenetic studies on S. reticulata subsp. amurensis and its allies.

13.
Nat Commun ; 12(1): 4191, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234149

RESUMO

The vaginal and uterine microbiota play important roles in the health of the female reproductive system. However, the interactions among the microbes in these two niches and their effects on uterine health remain unclear. Here we profile the vaginal and uterine microbial samples of 145 women, and combine with deep mining of public data and animal experiments to characterize the microbial translocation in the female reproductive tract and its role in modulating uterine health. Synchronous variation and increasing convergence of the uterine and vaginal microbiome with advancing age are shown. We also find that transplanting certain strains of vaginal bacteria into the vagina of rats induces or reduces endometritis-like symptoms, and verify the damaging or protective effects of certain vaginal bacteria on endometrium. This study clarifies the interdependent relationship of vaginal bacterial translocation with uterine microecology and endometrial health, which will undoubtedly increase our understanding of female reproductive health.


Assuntos
Translocação Bacteriana , Endometrite/microbiologia , Microbiota , Saúde Reprodutiva , Vagina/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Doença Crônica , Estudos de Coortes , DNA Bacteriano/isolamento & purificação , Modelos Animais de Doenças , Endometrite/epidemiologia , Endometrite/patologia , Endométrio/microbiologia , Endométrio/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Fatores de Proteção , RNA Ribossômico 16S/genética , Ratos , Fatores de Risco , Saúde da Mulher , Adulto Jovem
14.
J Genet Genomics ; 48(1): 32-39, 2021 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-33663937

RESUMO

The oral microbiota plays an important role in the development of various diseases, whereas its association with gestational diabetes mellitus (GDM) remains largely unclear. The aim of this study is to identify biomarkers from the oral microbiota of GDM patients by analyzing the microbiome of the saliva and dental plaque samples of 111 pregnant women. We find that the microbiota of both types of oral samples in GDM patients exhibits differences and significantly varies from that of patients with periodontitis or dental caries. Using bacterial biomarkers from the oral microbiota, GDM classification models based on support vector machine and random forest algorithms are constructed. The area under curve (AUC) value of the classification model constructed by combination of Lautropia and Neisseria in dental plaque and Streptococcus in saliva reaches 0.83, and the value achieves a maximum value of 0.89 by adding clinical features. These findings suggest that certain bacteria in either saliva or dental plaque can effectively distinguish women with GDM from healthy pregnant women, which provides evidence of oral microbiome as an informative source for developing noninvasive biomarkers of GDM.


Assuntos
Cárie Dentária , Diabetes Gestacional , Microbiota , Diabetes Gestacional/microbiologia , Feminino , Humanos , Gravidez , Gestantes , Saliva/microbiologia
15.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 35(1): 32-7, 2010 Jan.
Artigo em Zh | MEDLINE | ID: mdl-20130362

RESUMO

OBJECTIVE: To investigate the change of emotion and striatum dopamine transporter(DAT) expression in adult male rats experiencing maternal deprivation, and to explore whether DNA methylation is involved in the regulatory mechanism of DAT expression. METHODS: Newborn rats were randomly divided into 2 groups: a maternal separation group (n=16) and a control group (n=14). The maternal deprivation group were separated from their mother for 6 hours (09:00-15:00) per day from postnatal day 1 to 14, while the controls (n=14) without the deprivation. When the rats in the 2 groups were 12 week, their spontaneous anxiety levels and exploratory ability in novel environments were assessed by an elevated plus maze and an open field test. DAT mRNA expression in the striatum was detected by reverse transcription-PCR, and its DNA methylation level was measured by bisulfated DNA sequencing. RESULTS: Maternally-deprived rats showed lower ability of exploring in a new environment and lower levels of anxiety than the controls. The expression of DAT mRNA in the striatum of the maternal separation group (0.236+/-0.043) was significantly lower than that in the control group (0.480+/-0.107) (P<0.05). However the DNA methylation level in the promoter region of DAT was not significantly different between the 2 groups. CONCLUSION: Maternal deprivation influenced the emotion and expression of dopamine transporter in adult rats and DNA methylation may not be involved.


Assuntos
Corpo Estriado/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Emoções/fisiologia , Privação Materna , Estresse Fisiológico/fisiologia , Animais , Animais Recém-Nascidos , Sequência de Bases , Metilação de DNA , Proteínas da Membrana Plasmática de Transporte de Dopamina/genética , Masculino , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley
16.
ACS Appl Mater Interfaces ; 12(14): 16367-16375, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32208675

RESUMO

Here we synthesized two new isostructural MOFs (FJU-82-Co/FJU-82-Zn) and first observed that tuning of the proton conductivity may provide an effective strategy to improve the electrocatalytic OER perfomances of isostructural crystalline MOF materials. The conductivity value for FJU-82-Co is 7.40 × 10-5 S cm-1, which is 127-fold that for FJU-82-Zn with 5.80 × 10-7 S cm-1 at 60 °C and 98% RH, while the overpotential of FJU-82-Co is 0.57 V at 1 mA cm-2, which is better than that of FJU-82-Zn with 1.17 V.

17.
Chempluschem ; 83(11): 1044-1051, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31950726

RESUMO

Here we propose a new strategy in which two isomorphic metal-organic frameworks (MOFs) [FJU-40-H (a) and FJU-40-NH2 (b)] are used to construct the core-shell material MOF@MOF. This strategy based on nitrogen doping and specific surface has resulted in an N-doped porous carbon (NPC) material in a one-step thermal treatment in N2 atmosphere; this material displays high catalytic activity for the oxygen reduction reaction (ORR). The materials were analyzed by SEM, XPS, Raman, specific surface area, pore size distribution and electrochemical measurements. It was found that NPC derived from the core-shell MOF@MOF can provide excellent catalytic ORR performance exceeding that of the single MOF. The onset potential is NPC-b@a-4h (-0.068 V)>NPC-a@b-4h (-0.075 V)>NPC-a-4h (-0.109 V)>NPC-b-4h (-0.113 V). Moreover, the results also show that the performance of NPC-b@a (n=4.15) is better than that of NPC-a@b (n=3.32), which means the different nitrogen content of ligands inside and outside of the core affects the ORR properties.

18.
Polymers (Basel) ; 8(4)2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30979210

RESUMO

In this article, reduced graphene oxide (RGO)/carboxymethyl chitosan (CMC) composites (RGO/CMC) were synthesized by a hydrothermal method through in-situ reduction and modification of graphene oxide (GO) in the presence of CMC. An electrochemical sensor for the determination of Cu(II) by differential pulse anodic stripping voltammetry (DPASV) was constructed by an electrode modified with RGO/CMC. The fabricated electrochemical sensor shows a linear range of 0.02⁻1.2 µmol·L-1, a detection limit of 3.25 nmol·L-1 (S/N = 3) and a sensitivity of 130.75 µA·µmol·L-1·cm-2, indicating the sensor has an excellent detection performance for Cu(II).

19.
Polymers (Basel) ; 8(6)2016 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-30979332

RESUMO

The determination of brominated flame retardants is of great importance, but remains a challenge. Particularly, universal and facile approaches are limited. Here we report a new general approach, combining molecular imprinting and electrospinning, for the efficient and facile imprinting sensor of 2,4,6-tribromophenol (TBP), which was used as a "novel" brominated flame retardant. With TBP as the template molecular, ß-cyclodextrin (ß-CD) as the functional monomer, and poly-vinylbutyral (PVB) as the electro-spinning matrix, the nanofiber film was deposited on the glassy carbon electrode (GCE) via electrospinning technique directly. The ß-CD-PVB/GCE sensor system exhibited excellent TBP sensing performances, such as a low detection limit (6.29 × 10-10 mol·L-1) at room temperature, selective recognition to TBP/phenol/4-methyl-phenol, and good regeneration performance. The approach of fabricating a molecular imprinting nanofiber sensor may shed new light in the detection of other phenolic pollutants.

20.
Artigo em Zh | MEDLINE | ID: mdl-15698490

RESUMO

OBJECTIVE: To investigate the effects of adipose tissue extract on growth of rat skin in vitro. METHODS: Neonatal rat skin (area of 2 mm x 2 mm) was cultured in Dulbecco's modified Eagle's medium (DMEM) containing 10% adipose tissue extract and 10% phosphate buffered solution (PBS). After being cultured for 6 days, the area of skin was measured. RESULTS: Skin in both groups grew in area. With the addition of adipose tissue extract, the skin measured (8.43+/-1.40) mm2 in area after 6 days, and it was approximately 2 times of that of PBS group, in which the skin area was (4.18+/-1.11) mm2. The difference was statistically significant (P<0.05). CONCLUSION: Adipose tissue extract promote skin growth, which may be attributed to the presence of some growth factors in the extract.


Assuntos
Tecido Adiposo , Regeneração/efeitos dos fármacos , Pele/efeitos dos fármacos , Extratos de Tecidos/farmacologia , Animais , Técnicas In Vitro , Masculino , Ratos , Ratos Wistar , Suínos
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