Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 96
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
J Environ Manage ; 355: 120504, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38447513

RESUMO

Ammonia-oxidation process directly contribute to soil nitrous oxide (N2O) emissions in agricultural soils. However, taxonomy of the key nitrifiers (within ammonia oxidising bacteria (AOB), archaea (AOA) and complete ammonia oxidisers (comammox Nitrospira)) responsible for substantial N2O emissions in agricultural soils is unknown, as is their regulation by soil biotic and abiotic factors. In this study, cumulative N2O emissions, nitrification rates, abundance and community structure of nitrifiers were investigated in 16 agricultural soils from major crop production regions of China using microcosm experiments with amended nitrogen (N) supplemented or not with a nitrification inhibitor (nitrapyrin). Key nitrifier groups involved in N2O emissions were identified by comparative analyses of the different treatments, combining sequencing and random forest analyses. Soil cumulative N2O emissions significantly increased with soil pH in all agricultural soils. However, they decreased with soil organic carbon (SOC) in alkaline soils. Nitrapyrin significantly inhibited soil cumulative N2O emissions and AOB growth, with a significant inhibition of the AOB Nitrosospira cluster 3a.2 (D11) abundance. One Nitrosospira multiformis-like OTU phylotype (OTU34), which was classified within the AOB Nitrosospira cluster 3a.2 (D11), had the greatest importance on cumulative N2O emissions and its growth significantly depended on soil pH and SOC contents, with higher growth at high pH and low SOC conditions. Collectively, our results demonstrate that alkaline soils with low SOC contents have high N2O emissions, which were mainly driven by AOB Nitrosospira cluster 3a.2 (D11). Nitrapyrin can efficiently reduce nitrification-related N2O emissions by inhibiting the activity of AOB Nitrosospira cluster 3a.2 (D11). This study advances our understanding of key nitrifiers responsible for high N2O emissions in agricultural soils and their controlling factors, and provides vital knowledge for N2O emission mitigation in agricultural ecosystems.


Assuntos
Ecossistema , Solo , Solo/química , Amônia/química , Carbono , Oxirredução , Archaea , Nitrificação , Microbiologia do Solo
2.
Angew Chem Int Ed Engl ; 61(52): e202212005, 2022 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-36314469

RESUMO

Atropisomers bearing multiple stereogenic axes are of increasing importance to the field of material science, pharmaceuticals, and catalysis. However, the atroposelective construction of multi-axis atropisomers remains rare and challenging, due to the intrinsical difficulties in the stereo-control of the multiple stereogenic axes. Herein, we demonstrate a single-step construction of a new class of 1,2-diaxially chiral triaryl α-pyranones by an N-heterocyclic carbene organocatalytic asymmetric [3+3] annulation of well-designed alkynyl acylazolium precursors and enolizable sterically hindered 2-aryl ketones. The protocol features broad substrate scope (>50 examples), excellent stereo-control (most cases >20 : 1 dr, up to 99.5 : 0.5 er), and potentially useful synthetic applications. The success of this reaction relies on the rational design of structurally matched reaction partners and the careful selection of the asymmetric catalytic system. DFT calculations have also been performed to discover and rationalize the origin of the high stereoselectivity of this reaction.

3.
Environ Microbiol ; 23(2): 588-599, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32249528

RESUMO

Viruses can affect microbial dynamics, metabolism and biogeochemical cycles in aquatic ecosystems. However, viral diversity and functions in agricultural soils are poorly known, especially in the rhizosphere. We used virome analysis of eight rhizosphere and bulk soils to study viral diversity and potential biogeochemical impacts in an agro-ecosystem. The order Caudovirales was the predominant viral type in agricultural soils, with Siphoviridae being the most abundant family. Phylogenetic analysis of the terminase large subunit of Caudovirales identified high viral diversity and three novel groups. Viral community composition differed significantly between bulk and rhizosphere soils. Soil pH was the main environmental driver of the viral community structure. Remarkably, abundant auxiliary carbohydrate-active enzyme (CAZyme) genes were detected in viromes, including glycoside hydrolases, carbohydrate esterases and carbohydrate-binding modules. These results demonstrate that virus-encoded putative auxiliary metabolic genes or metabolic genes that may change bacterial metabolism and indirectly contribute to biogeochemical cycling, especially carbon cycling, in agricultural soil.


Assuntos
Biodiversidade , Microbiologia do Solo , Vírus/isolamento & purificação , Agricultura , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Ecossistema , Concentração de Íons de Hidrogênio , Filogenia , Rizosfera , Solo/química , Vírus/classificação , Vírus/genética
4.
Environ Microbiol ; 23(4): 1907-1924, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32996254

RESUMO

Plants harbour highly diverse mycobiomes which sustain essential functions for host health and productivity. However, ecological processes that govern the plant-mycobiome assembly, interactions and their impact on ecosystem functions remain poorly known. Here we characterized the ecological role and community assembly of both abundant and rare fungal taxa along the soil-plant continuums (rhizosphere, phyllosphere and endosphere) in the maize-wheat/barley rotation system under different fertilization practices at two contrasting sites. Our results indicate that mycobiome assembly is shaped predominantly by compartment niche and host species rather than by environmental factors. Moreover, crop-associated fungal communities are dominated by few abundant taxa mainly belonging to Sordariomycetes and Dothideomycetes, while the majority of diversity within mycobiomes are represented by rare taxa. For plant compartments, the abundant sub-community is mainly determined by stochastic processes. In contrast, the rare sub-community is more sensitive to host selection and mainly governed by deterministic processes. Furthermore, our results demonstrate that rare taxa play an important role in fungal co-occurrence network and ecosystem functioning like crop yield and soil enzyme activities. These results significantly advance our understanding of crop mycobiome assembly and highlight the key role of rare taxa in sustaining the stability of crop mycobiomes and ecosystem functions.


Assuntos
Produtos Agrícolas/microbiologia , Micobioma , Ecossistema , Fungos/genética , Rizosfera , Microbiologia do Solo
5.
New Phytol ; 229(2): 1091-1104, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32852792

RESUMO

Plant microbiomes are essential to host health and productivity but the ecological processes that govern crop microbiome assembly are not fully known. Here we examined bacterial communities across 684 samples from soils (rhizosphere and bulk soil) and multiple compartment niches (rhizoplane, root endosphere, phylloplane, and leaf endosphere) in maize (Zea mays)-wheat (Triticum aestivum)/barley (Hordeum vulgare) rotation system under different fertilization practices at two contrasting sites. Our results demonstrate that microbiome assembly along the soil-plant continuum is shaped predominantly by compartment niche and host species rather than by site or fertilization practice. From soils to epiphytes to endophytes, host selection pressure sequentially increased and bacterial diversity and network complexity consequently reduced, with the strongest host effect in leaf endosphere. Source tracking indicates that crop microbiome is mainly derived from soils and gradually enriched and filtered at different plant compartment niches. Moreover, crop microbiomes were dominated by a few dominant taxa (c. 0.5% of bacterial phylotypes), with bacilli identified as the important biomarker taxa for wheat and barley and Methylobacteriaceae for maize. Our work provides comprehensive empirical evidence on host selection, potential sources and enrichment processes for crop microbiome assembly, and has important implications for future crop management and manipulation of crop microbiome for sustainable agriculture.


Assuntos
Microbiota , Microbiologia do Solo , Bactérias , Raízes de Plantas , Rizosfera
6.
J Mol Cell Cardiol ; 128: 11-24, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30659837

RESUMO

Macrophage-mediated inflammatory responses occur throughout all stages of atherosclerosis. DNA methylation is one of the critical epigenetic mechanisms and is associated with the development of atherosclerosis. The underlying mechanism of epigenetic regulation of macrophage inflammation (M1 activation) remains unclear. Here we aim to study the role of DNA methyltransferase 1 (DNMT1) in modulating macrophage inflammation and atherosclerosis. DNMT1 expression is up-regulated in THP-1-derived macrophages upon treatment with lipopolysaccharide (LPS) and interferon-gamma (IFN-γ). Overexpression of DNMT1 promotes the LPS- and IFN-γ-induced M1 activation whereas inhibition of DNMT1 attenuates it. Consistently, DNMT1 expression is elevated in macrophages in atherosclerotic plaques from human and mouse specimens; compared with the Dnmt1wild-type, myeloid Dnmt1 deficiency in mice in an Apolipoprotein E (ApoE) knockout background or receiving AAV-PSCK9 injection and carotid partial ligation results in ameliorated atheroma formation and suppressed plaque inflammation. The promoter regions of atheroprotective Krüppel-like factor 4 (KLF4) are hypermethylated in M1- activated macrophages. DNMT1 down-regulates the expression of KLF4, probably through catalyzing DNA methylation of the promoter regions of KLF4. Gain- and loss-of function study of KLF4 indicates that the DNMT1-mediated macrophage M1 activation is dependent on KLF4. Our data demonstrate a proatherogenic role for DNMT1 as a defining factor in macrophage inflammation both in vitro and in vivo. DNMT1 promotes macrophage M1 activation by suppressing KLF4 expression. Thus macrophage-specific DNMT1 inhibition may provide an attractive therapeutic potential to prevent or reduce atherosclerosis.


Assuntos
Aterosclerose/genética , DNA (Citosina-5-)-Metiltransferase 1/genética , Inflamação/genética , Fatores de Transcrição Kruppel-Like/genética , Animais , Apolipoproteínas E/genética , Aterosclerose/patologia , Metilação de DNA/genética , Epigênese Genética , Regulação da Expressão Gênica/genética , Humanos , Inflamação/patologia , Interferon gama/genética , Fator 4 Semelhante a Kruppel , Lipopolissacarídeos/farmacologia , Macrófagos/patologia , Camundongos , Camundongos Knockout , Mutação , Regiões Promotoras Genéticas/genética
7.
J Cell Physiol ; 234(9): 16226-16237, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30767206

RESUMO

OBJECTIVE: To study the role and mechanism of microRNA 19b (miR-19b) in hypoxia/reoxygenation (H/R)-induced injury by targeting PTEN. METHODS: PC12 and BV2 cells induced by H/R were treated with miR-19b mimics/inhibitors or small interfering PTEN (si-PTEN), respectively. Lactate dehydrogenase (LDH) level, malondialdehyde (MDA), and superoxide dismutase (SOD) content was detected. Besides, cell viability and apoptosis were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, Hoechst33342 staining, and flow cytometry, whereas mitochondrial membrane potential (MMP) tested by JC-1 assay, and reactive oxygen species (ROS) evaluated by the dichloro-dihydro-fluorescein diacetate assay. The ischemia/reperfusion (I/R) rats model was used to investigate the effects of miR-19b in vivo test. The infarct area and apoptosis rates in brain tissues were detected by 2,3,5-triphenyltetrazolium chloride and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling staining, respectively. miR-19b and PTEN/PI3K/Akt pathway-related proteins were detected by quantitative reverse-transcription polymerase chain reaction and western blot analysis. RESULTS: miR-19b mimics could reduce LDH, MDA, and ROS levels and decline cell apoptosis, but enhance the viability, MMP, and SOD activity with decreased PTEN and cleaved caspase, as well as increased p-Akt/Akt and Bcl-2/Bax ratios in H/R-induced PC12 and BV2 cells. However, miR-19b inhibitors led to completely opposite results to aggravate H/R-induced cell injury. Meanwhile, si-PTEN could reverse the effect of miR-19b inhibitors on H/R-induced injury. Moreover, treatment with miR-19b agomir after I/R in vivo sufficiently decreased infarct area and reduced apoptosis rates by targeting PTEN through the regulation of the PI3K/Akt pathway. CONCLUSION: miR-19b could inhibit oxidative stress, enhance cell MMP, promote cell survival, and inhibit cell apoptosis by targeting PTEN via the regulation of the PI3K/Akt pathway, thus playing the neuronal protective effects.

8.
J Med Virol ; 91(7): 1342-1350, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30854653

RESUMO

Low-cost, accurate high-risk human papillomavirus (HR-HPV) tests are needed for cervical cancer screening in limited-resource settings. More than 200 cervical cytological specimens from hospital patients were collected and analyzed for a real-world study. We evaluated the analytical and clinical performance of four widely used HR-HPV test (Tellgen, Hybribio, Liferiver, and Sansure) based on real-time polymerase chain reaction technology platforms, compared with the cobas test. Cervical intraepithelial neoplasia grade 2 or worse lesions (CIN2+) were set as the disease endpoint, and all the five HPV tests were performed with equal sensitivity (McNemar's test; P = 0.971) and specificity (McNemar's test; P = 0.953). All genotyping using the INNO-LiPA HPV test showed that HPV-16, -52, and -54 were the most common types among CIN2+ cases. Overall, the four HR-HPV tests analyzed appear to be as effective as the cobas HPV test in both agreement and clinical performance. Therefore, each of these low-cost HPV test kits could be implemented in limited-resource settings to accelerate the control of cervical cancer. However, we suggest that there is a need to further standardize and optimize testing around clinical sensitivity and specificity.


Assuntos
Técnicas de Laboratório Clínico/normas , Detecção Precoce de Câncer/métodos , Recursos em Saúde , Infecções por Papillomavirus/diagnóstico , Displasia do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Adulto , Idoso , Colo do Útero/patologia , Colo do Útero/virologia , Técnicas de Laboratório Clínico/economia , Técnicas de Laboratório Clínico/métodos , Detecção Precoce de Câncer/instrumentação , Feminino , Humanos , Pessoa de Meia-Idade , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , Kit de Reagentes para Diagnóstico/economia , Kit de Reagentes para Diagnóstico/normas , Sensibilidade e Especificidade , Neoplasias do Colo do Útero/virologia , Adulto Jovem , Displasia do Colo do Útero/virologia
9.
Liver Int ; 39(1): 147-157, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30178471

RESUMO

BACKGROUND & AIMS: Resistance to EGFR-targeted therapy is a major obstacle in hepatocellular carcinoma (HCC) treatment, but its underlying mechanism remains unclear. Autophagy plays a vital role in antitumour treatment. Our previous study suggested that p57 is associated with autophagy and cisplatin resistance. The present study aimed to investigate whether p57 can enhance the sensitivity of HCC cells to Erlotinib (Er)/Cetuximab(C-225) and further explore the potential mechanisms of Er/C-225 resistance. METHODS: HCC cells were transfected with pIRES2-EGFP-p57 and pIRES2-EGFP-nc, accompanied by Er/C-225 treatment. Cell viability was detected by an Annexin apoptosis kit and MTT assay. Xenograft experiments were performed to study the function of p57 in the treatment of Er/C-225 in vivo. The level of autophagy was determined by analysis of the appearance of autophagic vacuoles. Western blotting was used to investigate the potential pathways involved. RESULTS: Up-regulation of p57 decreased the level of Er/C-225-induced autophagy and enhanced the decrease in Er/C-225-induced cell viability. P57 overexpression combined with CQ treatment further enhanced the therapeutic efficiency of Er/C-225. The xenograft experiment verified that p57 up-regulation sensitizes HCC cells to Er/C-225. Moreover, a mechanistic investigation demonstrated that the up-regulation of p57 resulted in a decrease of LC3B-II and beclin-1, and an increase in p-PI3K, p-AKT and p-mTOR protein expressions. CONCLUSIONS: Through activating the PI3K/AKT/mTOR signalling pathway, p57 can reverse Er/C-225-induced autophagy, and thereby increase the therapeutic efficiency of Er/C-225 treatment. Given these results, p57 up-regulation may be applicable as a therapeutic strategy to improve EGFR-targeted therapy in HCC.


Assuntos
Antineoplásicos/farmacologia , Autofagia , Carcinoma Hepatocelular/genética , Inibidor de Quinase Dependente de Ciclina p57/genética , Receptores ErbB/antagonistas & inibidores , Neoplasias Hepáticas/genética , Animais , Apoptose , Carcinoma Hepatocelular/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células , Cetuximab/farmacologia , Inibidor de Quinase Dependente de Ciclina p57/metabolismo , Cloridrato de Erlotinib/farmacologia , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Mol Med ; 24(1): 61, 2018 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-30486773

RESUMO

BACKGROUND: There have been a number of reports implicating the association of microRNAs (miRs) and the MAPK signaling pathway with the dopaminergic neuron, which is involved in the development of Parkinson's disease (PD). The present study was conducted with aims of exploring the role of miR-96 in the activation of iNOS and apoptosis of dopaminergic neuron through the MAPK signaling pathway in mice with PD. METHODS: The miR and the differentially expressed gene in PD were screened out and the relationship between them was verified. A mouse model of PD induced by MPTP and was then constructed and treated with miR-96 mimic/inhibitor and CACNG5 overexpression plasmid to extract nigral dopaminergic neuron for the purpose of detecting the effect of miR-96 on PD. The TH and iNOS positive neuronal cells, the apoptotic neuronal cells by TUNEL staining, and expression of miR-96, CACNG5, iNOS, p38MAPK, p-p38MAPK, c-Fos, Bax, and Bcl-2 in substantia nigra dopaminergic neuronal tissues were evaluated. RESULTS: The results obtained from the aforementioned procedure were then verified by cell culture of the SH-SY5Y cells, followed by treatment with miR-96 mimic/inhibitor, CACNG5 overexpression plasmid and the inhibitor of the MAPK signaling pathway. CACNG5 was confirmed as a target gene of miR-96. The inhibition of miR-96 resulted in a substantial increase in nigral cells, TH positive cells and expression of CACNG5 and Bcl-2 in nigral dopaminergic neuronal tissues, and a decrease in iNOS positive cells, apoptotic neuronal cells, and expression of iNOS, p38MAPK, p-p38MAPK, c-Fos, and Bax. CONCLUSION: The above results implicated that the downregulation of miR-96 inhibits the activation of iNOS and apoptosis of dopaminergic neuron through the blockade of the MAPK signaling pathway by promoting CACNG5 in mice with PD.


Assuntos
Canais de Cálcio/fisiologia , MicroRNAs/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Animais , Apoptose , Linhagem Celular , Modelos Animais de Doenças , Neurônios Dopaminérgicos/fisiologia , Regulação para Baixo , Humanos , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos Endogâmicos C57BL , Óxido Nítrico Sintase Tipo II/fisiologia
11.
Cell Physiol Biochem ; 51(3): 1179-1192, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30481780

RESUMO

BACKGROUND/AIMS: Previous studies have confirmed that microRNAs are involved in the metastasis and epithelial-mesenchymal transition (EMT) of malignancies. In this study, we examined whether miR-650 promotes the migration, invasion, and EMT of hepatocellular carcinoma (HCC) cells by targeting the large tumor suppressor kinase 2 gene (LATS2). METHODS: qRT-PCR was used to detect expression of miR-650 in HCC tissues and paired normal tissues. MTT and Transwell assay were used to observe the effect of miR-650 on proliferation, migration and invasion of HCC cells. Western blot assay and Immunohistochemistry were performed to demonstrate association between miR-650 expression level and epithelial-mesenchymal transition (EMT) related protein. Mechanistically, Reporter luciferase assay was performed to reveal whether large tumor suppressor kinase 2 (LATS2) was a direct target of miR-650 in HCC cells. RESULTS: We observed that miR-650 levels were largely up-regulated in HCC tissues, and that the increased expression was closely associated with the adverse clinical features of HCC patients. Additionally, the expression of LATS2, which was identified as a direct target of miR-650, can counteract the effects of miR-650 in HCC. Furthermore, we demonstrated that high miR-650 expression levels and low LATS2 expression levels in tumors may indicate a poor prognosis for HCC patients. CONCLUSION: In conclusion, the miR-650/LATS2 pathway may serve as a novel prognostic biomarker and an attractive therapeutic target for HCC patients.


Assuntos
Carcinoma Hepatocelular/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , MicroRNAs/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Supressoras de Tumor/genética , Carcinoma Hepatocelular/patologia , Movimento Celular , Regulação para Baixo , Transição Epitelial-Mesenquimal , Feminino , Células Hep G2 , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade
12.
Microb Ecol ; 75(2): 375-386, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28825127

RESUMO

A substantial gap remains in our understanding of the abundance, diversity, and ecology of viruses in soil although some advances have been achieved in recent years. In this study, four soil samples according to the salinity gradient from shore to inland in East China have been characterized. Results showed that spherical virus particles represented the largest viral component in all of the four samples. The viromes had remarkably different taxonomic compositions, and most of the sequences were derived from single-stranded DNA viruses, especially from families Microviridae and Circoviridae. Compared with viromes from other aquatic and sediment samples, the community compositions of our four soil viromes resembled each other, meanwhile coastal sample virome closely congregated with sediment and hypersaline viromes, and high salinity paddy soil sample virome was similar with surface sediment virome. Phylogenetic analysis of functional genes showed that four viromes have high diversity of the subfamily Gokushovirinae in family Microviridae and most of Circoviridae replicase protein sequences grouped within the CRESS-DNA viruses. This work provided an initial outline of the viral communities in marine-terrestrial ecotone and will improve our understanding of the ecological functions of soil viruses.


Assuntos
Biodiversidade , Vírus de DNA/isolamento & purificação , Microbiologia do Solo , China , Vírus de DNA/classificação , Vírus de DNA/genética , Ecossistema , Filogenia , Salinidade , Solo/química
13.
Am J Physiol Cell Physiol ; 310(7): C542-57, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26739494

RESUMO

Given the fundamental role of ß-catenin signaling in intestinal epithelial cell proliferation and the growth-promoting function of protein kinase D1 (PKD1) in these cells, we hypothesized that PKDs mediate cross talk with ß-catenin signaling. The results presented here provide several lines of evidence supporting this hypothesis. We found that stimulation of intestinal epithelial IEC-18 cells with the G protein-coupled receptor (GPCR) agonist angiotensin II (ANG II), a potent inducer of PKD activation, promoted endogenous ß-catenin nuclear localization in a time-dependent manner. A significant increase was evident within 1 h of ANG II stimulation (P< 0.01), peaked at 4 h (P< 0.001), and declined afterwards. GPCR stimulation also induced a marked increase in ß-catenin-regulated genes and phosphorylation at Ser(552) in intestinal epithelial cells. Exposure to preferential inhibitors of the PKD family (CRT006610 or kb NB 142-70) or knockdown of the isoforms of the PKD family prevented the increase in ß-catenin nuclear localization and phosphorylation at Ser(552) in response to ANG II. GPCR stimulation also induced the formation of a complex between PKD1 and ß-catenin, as shown by coimmunoprecipitation that depended on PKD1 catalytic activation, as it was abrogated by cell treatment with PKD family inhibitors. Using transgenic mice that express elevated PKD1 protein in the intestinal epithelium, we detected a marked increase in the localization of ß-catenin in the nucleus of crypt epithelial cells in the ileum of PKD1 transgenic mice, compared with nontransgenic littermates. Collectively, our results identify a novel cross talk between PKD and ß-catenin in intestinal epithelial cells, both in vitro and in vivo.


Assuntos
Núcleo Celular/metabolismo , Mucosa Intestinal/metabolismo , Proteína Quinase C/metabolismo , Receptor Cross-Talk/fisiologia , beta Catenina/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Linhagem Celular , Imunofluorescência , Técnicas de Silenciamento de Genes , Humanos , Processamento de Imagem Assistida por Computador , Immunoblotting , Imunoprecipitação , Camundongos , Camundongos Transgênicos , Fosforilação , RNA Interferente Pequeno , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Serina/metabolismo , Transfecção
14.
Biol Pharm Bull ; 39(2): 267-71, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26632211

RESUMO

In this work, the catalytic activity of calix[8]arene sulfonic acid was successfully investigated for the famous Biginelli reaction. Under ultrasonic irradiation, calix[8]arene sulfonic acid could efficiently catalyzed the three-component reaction of aldehydes with ethyl acetoacetate and urea or thiourea in ethanol to afford the corresponding 3,4-dihydropyrimidin-2(1H)-ones/thiones in 46-93%. The advantages of this method are the easy isolated procedure, short reaction time and low cost of the catalyst.


Assuntos
Calixarenos/química , Tionas/síntese química , Catálise , Estrutura Molecular , Tionas/química , Ultrassom
15.
Langmuir ; 31(29): 8162-7, 2015 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-26154589

RESUMO

Hierarchical nanowires (HNWs) exhibit unique properties and have wide applications, while often suffering from imperfect structure. Herein, we report a facile strategy toward ultrathin CdS HNWs with monocrystal structure, where a continuous-wave (CW) Nd:YAG laser is employed to irradiate an oleic acid (OA) solution containing precursors and a light absorber. The high heating rate and large temperature gradient generated by the CW laser lead to the rapid formation of tiny zinc-blende CdS nanocrystals which then line up into nanowires with the help of OA molecules. Next, the nanowires experience a phase transformation from zinc-blende to wurtzite structure, and the transformation-induced stress creates terraces on their surface, which promotes the growth of side branches and eventually results in monocrystal HNWs with an ultrathin diameter of 24 nm. The one-step synthesis of HNWs is conducted in air and completes in just 40 s, thus being very simple and rapid. The prepared CdS HNWs display photocatalytic performance superior to their nanoparticle counterparts, thus showing promise for catalytic applications in the future.

16.
Langmuir ; 31(8): 2251-5, 2015 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-25689447

RESUMO

Green and simple synthesis of high-quality colloidal quantum dots (CQDs) is of great importance and highly anticipated yet not fully implemented. Herein, we achieve the direct conversion of natural minerals to highly uniform, crystalline lead sulfide CQDs based on laser irradiation in liquid. The trivial fragmentation of mineral particles by an intense nanosecond laser was found to create a localized high degree of monomer supersaturation in oleic acid, initiating the LaMer growth of uniform CQDs. The photoconductive device made of these CQDs exhibits a competitive temporal response of photocurrent with those highly sensitive photodetectors based on PbS CQDs reported in the literature. Our synthesis strategy paves the way for the most environmentally friendly and convenient mass production of high-quality uniform CQDs.


Assuntos
Chumbo/química , Pontos Quânticos , Sulfetos/química , Coloides/química , Tamanho da Partícula , Propriedades de Superfície
17.
Int J Syst Evol Microbiol ; 65(Pt 5): 1583-1586, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25713036

RESUMO

A novel psychrophilic strain, SSB001(T), was isolated from an alpine swamp meadow soil in Tibet, China, and identified as a representative of a novel phylogenetic subclade in the genus Paenibacillus , with Paenibacillus antarcticus (96.2%), Paenibacillus macquariensis (96.53%) and Paenibacillus glacialis (96.2%) as the most closely related species on the basis of 16S rRNA gene sequence analyses. The strain was distinguished from defined species of the genus Paenibacillus by further study of rpoB gene sequences, phenotypic characterization, cellular fatty acid composition, quinones, polar lipids and meso-diaminopimelic acid in the peptidoglycan. Based upon these results, we propose the strain as a representative of a novel species named Paenibacillus tibetensis sp. nov., with SSB001(T) ( =ACCC 19728(T) =DSM 29321(T)) as the type strain. The DNA G+C content (mol%) of strain SSB001(T) was 40.18 mol% (HPLC).


Assuntos
Paenibacillus/classificação , Filogenia , Microbiologia do Solo , Áreas Alagadas , Composição de Bases , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Genes Bacterianos , Dados de Sequência Molecular , Paenibacillus/genética , Paenibacillus/isolamento & purificação , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Tibet , Vitamina K 2/análogos & derivados , Vitamina K 2/química
18.
Microb Ecol ; 69(1): 135-45, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25074792

RESUMO

Unraveling the distribution patterns of plants and animals along the elevational gradients has been attracting growing scientific interests of ecologists, whether the microbial communities exhibit similar elevational patterns, however, remains largely less documented. Here, we investigate the biogeographic distribution of soil archaeal and bacterial communities across three vertical climate zones (3,106-4,479 m.a.s.l.) in Mt. Shegyla on the Tibetan Plateau, by combining quantitative PCR and high-throughput barcoded pyrosequencing approaches. Our results found that the ratio of bacterial to archaeal 16S rRNA gene abundance was negatively related with elevation. Acidobacteria dominated in the bacterial communities, Marine benthic group A dominated in the archaeal communities, and the relative abundance of both taxa changed significantly with elevation. At the taxonomic levels of domain, phylum, and class, more bacterial taxa than archaeal exhibited declining trend in diversity along the increasing elevational gradient, as revealed by Shannon and Faith's phylogenetic diversity indices. Unweighted UniFrac distance clustering showed that the bacterial communities from the mountainous temperate zone clustered together, whereas those from the subalpine cool temperate zone clustered together. However, the partitioning effect of elevational zones on the archaeal community was much weaker compared to that on bacteria. Redundancy analysis revealed that soil geochemical factors explained 58.3 % of the bacterial community variance and 75.4 % of the archaeal community variance. Taken together, we provide evidence that soil bacteria exhibited more apparent elevational zonation feature and decreased diversity pattern than archaea with increasing elevation, and distribution patterns of soil microbes are strongly regulated by soil properties along elevational gradient in this plateau montane ecosystem.


Assuntos
Archaea/genética , Bactérias/genética , Archaea/classificação , Bactérias/classificação , RNA Ribossômico 16S/genética , Microbiologia do Solo , Tibet
19.
BMC Complement Altern Med ; 14: 69, 2014 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-24555788

RESUMO

BACKGROUND: Deqi is a central concept in traditional Chinese acupuncture. We performed a secondary analysis on data from a larger randomized controlled trial (RCT) in order to assess the effect of acupuncture on deqi traits and pain intensity in primary dysmenorrhea. METHODS: A total of 60 primary dysmenorrhea patients were enrolled and randomly assigned to one of three treatment groups. Acupuncture was given at SP6, GB39 or nonacupoint. Subjective pain was measured by a 100-mm visual analogue scale (VAS) before and after acupuncture. The Massachusetts General Hospital acupuncture sensation scales (MASS) with minor modification was used to rate deqi sensations during acupuncture. RESULTS: The results showed that VAS scores of pain after acupuncture were significantly decreased comparing to before acupuncture treatment in all three groups (P = 0.000). However, no significant differences were found among three groups at the beginning or end of acupuncture treatment (P = 0.928, P = 0.419). CONCLUSIONS: There was no statistical difference among three groups in terms of intensity of deqi feeling. The types of sensation were similar across the groups with only minor differences among them. TRIAL REGISTRATION NUMBER: Controlled-Trials.com ISRCTN24863192.


Assuntos
Pontos de Acupuntura , Terapia por Acupuntura , Dismenorreia/terapia , Dor , Qi , Sensação , Índice de Gravidade de Doença , Adulto , Feminino , Humanos , Masculino , Medição da Dor , Adulto Jovem
20.
Water Res ; 249: 120913, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38039818

RESUMO

Estuary acts as a hotspot of greenhouse gases (GHGs, including CO2, CH4 and N2O) to the atmosphere. However, the GHGs budgets, including input/output fluxes through interfaces and biogeochemical source/sink processes in water columns, of the estuarine systems are still not well constrained due to the lacking of comprehensive observational data. Here, we presented the spatial distributions of GHGs of surface/bottom water and sediment porewater along the Pearl River Estuary (PRE) and adjacent region during summertime. The incorporation of the monitoring for the sediment-water interface (SWI) with these of the water-air interface (WAI) allows us to close the budget revealing additional information of internal consumption/production processes of the three GHGs. The oversaturated CO2 (481-7573 µatm), CH4 (289-16,990 %) and N2O (108-649 %) in surface water suggested PRE is a significant GHGs source to the atmosphere, in which CO2 is the major contributor accounting for 90 % of total global warming potential (GWP), leaving 2.8 % from CH4, and 7.2 % from N2O. Addition to the river input, the SWI releases GHGs to the overlying water with fluxes of 3.5 × 107, 10.8 × 104 and 0.7 × 104 mol d-1 for CO2, CH4 and N2O, respectively. Although all three GHGs exhibited emission to the atmosphere, our mass balance calculation showed that 16.9× 107 mol d-1 of CO2 and 1.0 × 104 mol d-1 of N2O were consumed, respectively, inside the estuary water body, while extra-production (13.8 × 104 mol d-1) of CH4 was demanded in the water body to support its output flux. This is the first experiment quantitatively assessing the importance of internal carbon and nitrogen biogeochemical processes in the PRE. Our finding is of guiding significance to constrain the GHGs budget and draw up realistic pathways for modeling works of GHGs prediction.


Assuntos
Gases de Efeito Estufa , Gases de Efeito Estufa/análise , Dióxido de Carbono , Rios , Estuários , Monitoramento Ambiental , Metano/análise , Óxido Nitroso/análise , Água , China
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa