Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Total Environ ; 914: 169629, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38157906

RESUMO

High level dissolved B, which poses risks to human health, has been widely observed in geothermal water. In the Guide Basin, NW China, a series of geothermal water samples along a fault show a wide range of B contents ranging from 3.14 to 8.33 mg/L, which are higher than the WHO Guideline value equaling 2.4 mg/L in drinking water. To identify the sources and fate of B, we conduct a comprehensive analysis of hydrochemistry and stable isotopes (D, 18O and 11B) of three thermal fields representing three stages of hydrogeochemical evolution (stages I, II and III). From stage I to III, there are trends of increasing mineral dissolution, which is supported by increasing mean reservoir temperature and concentrations of conservative elements (Cl, Na, K, Li and Si). Geothermal water in stage I with meteoric origin and the lowest reservoir temperature has the highest B/Na resulting from silicate dissolution and falls on the mixing line between granitoids and cold water on the plot of δ11B versus 1/B, showing the control of silicate dissolution. However, geothermal water in stage III has lower Ca, B Sr and B/Na than that in stage II. Because of the occurrence of other processes, geothermal water in stages II and III deviates from the LMWL. Compared with geothermal water in stage I, the increased Sr/Ca and decreased B/Ca show that B are removed by both coprecipitation and vapor separation. With the aid of B isotopes, we find vapor separation dominates in stage II, whereas carbonate precipitation dominates in stage III. Overall, a combined use of three isotopes (H, O and B) and three element ratios (B/Na, B/Ca and Sr/Ca) leads to a complete understanding of B cycle and hydrogeochemical evolution in hydrothermal systems.

2.
Brain Sci ; 13(10)2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37891839

RESUMO

Elevated glucocorticoid levels triggered by stress potentially contribute to sleep disturbances in stress-induced depression. However, sleep changes in response to elevated corticosterone (CORT), the major glucocorticoid in rodents, remain unclear. Here, we investigated the effects of acute or chronic CORT administration on sleep using electroencephalogram (EEG) and electromyography (EMG) recordings in freely moving mice. Acute CORT exposure rapidly promoted wakefulness, marked by increased episodes and enhanced EEG delta power, while simultaneously suppressing rapid eye movement (REM) and non-rapid eye movement (NREM) sleep, with the latter marked by decreased mean duration and reduced delta power. Prolonged 28-day CORT exposure led to excessive wakefulness and REM sleep, characterized by higher episodes, and decreased NREM sleep, characterized by higher episodes and reduced mean duration. EEG theta activity during REM sleep and delta activity during NREM sleep were attenuated following 28-day CORT exposure. These effects persisted, except for REM sleep amounts, even 7 days after the drug withdrawal. Elevated plasma CORT levels and depressive phenotypes were identified and correlated with observed sleep changes during and after administration. Fos expression significantly increased in the lateral habenula, lateral hypothalamus, and ventral tegmental area following acute or chronic CORT treatment. Our findings demonstrate that CORT exposure enhanced wakefulness, suppressed and fragmented NREM sleep, and altered EEG activity across all stages. This study illuminates sleep alterations during short or extended periods of heightened CORT levels in mice, providing a neural link connecting insomnia and depression.

3.
Nonlinear Dyn ; 104(4): 4671-4680, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33935366

RESUMO

This work concentrates on the dynamic analysis including bifurcation and chaos of a discrete ecological developmental systems. Specifically, it is a prey-predator-scavenger (PPS) system, which is derived by Euler discretization method. By choosing the step size h as a bifurcation parameter, we determine the set consists of all system's parameters, in which the system can undergo flip bifurcation (FB) and Neimark-Sacker bifurcation (NSB). The theoretical results are verified by some numerical simulations. It is shown that the discrete systems exhibit more interesting behaviors, including the chaotic sets, quasi-periodic orbits, and the cascade of period-doubling bifurcation in orbits of periods 2, 4, 8, 16. Finally, corresponding to the two bifurcation behaviors discussed, the maximum Lyapunov exponent is numerically calculated, which further verifies the rich dynamic characteristics of the discrete system.

4.
Psychiatry Res ; 278: 199-204, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31220786

RESUMO

Surface-based, two-dimensional regional homogeneity (2dReHo) was used in the current study to compare local functional synchronization of spontaneous neuronal activity between patients with bipolar disorder (BD) and healthy controls (HC), rather than volume-based, three-dimensional regional homogeneity (3dReHo) methods that have been previously described. Seventy-one BD patients and 113 HC participated in structural and resting-state fMRI scans. Participants ranged in age from 12 to 54 years. All subjects were rated with the Young Mania Rating Scale and the Hamilton Depression Rating Scale. BD patients showed reduced surface-based ReHo across the cortical surface, both at the global level and in the left ventral visual stream (VVS). Additionally, ReHo value across the cortical surface showed a significant negative correlation with age in both groups at the global level. Abnormal activity in the left VVS cortex may contribute to the pathogenesis of BD. Therefore, surface-based ReHo may be a useful index to explore the pathophysiology of BD.


Assuntos
Transtorno Bipolar/fisiopatologia , Córtex Cerebral/fisiopatologia , Neuroimagem Funcional/métodos , Adolescente , Adulto , Transtorno Bipolar/diagnóstico por imagem , Córtex Cerebral/diagnóstico por imagem , Criança , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Córtex Visual/diagnóstico por imagem , Córtex Visual/fisiopatologia , Adulto Jovem
7.
ISA Trans ; 67: 98-106, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28088310

RESUMO

This paper investigates the problem of optimal tracking performance of networked control systems (NCSs) with quantization and packet-dropouts. The system under consideration is linear time-invariant (LTI), multi-input multi-output (MIMO), where an H2 norm of error signal between the reference input and the system output is used as the tracking performance index. The impacts of packet-dropouts in the communication channel and the quantized input and output are studied. The goal is to obtain the minimal error in tracking a random signal, by searching through all possible stabilizing two-parameter controllers. It is shown that, the minimum value of tracking error is closely related to the reference input signal direction, the non-minimum phase zeros and unstable poles of the given plant, including the locations and directions. We also demonstrated the quantization error and the packet-dropouts may degrade the tracking performance. A typical example is given to evaluate the theoretical results.

8.
Immunol Lett ; 179: 102-113, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27666012

RESUMO

The nucleotide-binding and oligomerization domain-like receptor 3 (NLRP3) inflammasome participates in the pathogenesis of acute liver injury during sepsis. Bone marrow mesenchymal stem cells (BMSCs) attenuate sepsis through prostaglandin E 2 (PGE2) by increasing the interleukin-10 (IL-10) production of macrophages; moreover, NLRP3 inflammasome assembly is effectively regulated by IL-10 during infection. Whether BMSCs have an effect on the activation of the NLRP3 inflammasome and its underlying mechanism is unclear. Administering of BMSCs to mice or KCs after LPS stimulating have improved liver function and reduced activation of NLRP3 inflammasome in KCs. The beneficial effect of BMSCs was enhanced by over-expression of PGE2 and eliminated by silence of PGE2. Additionally, The IL-10 levels in the serum and supernatant were increased by given BMSCs and further increase by PGE2 over-expressed BMSCs, but decreased markedly by PGE2 silenced BMSCs. Furthermore, extracellular signal-regulated kinase 1 (ERK1) inhibitor reduced IL-10 production in KCs and blocked the inhibitory effect of PGE2 on the activation of the NLRP3 inflammasome. Our data reveal a novel mechanism of BMSC-mediated suppression of the activation of KCs through the secretion of PGE2 by BMSCs, which promotes KCs to secrete IL-10, leading to the inhibition of the NLRP3 inflammasome in KCs.


Assuntos
Dinoprostona/metabolismo , Inflamassomos/metabolismo , Células de Kupffer/metabolismo , Lipopolissacarídeos/imunologia , Hepatopatias/etiologia , Hepatopatias/metabolismo , Células-Tronco Mesenquimais/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Doença Aguda , Animais , Apoptose , Biomarcadores , Biópsia , Caspase 1/metabolismo , Técnicas de Cocultura , Citocinas/metabolismo , Modelos Animais de Doenças , Lipopolissacarídeos/efeitos adversos , Hepatopatias/patologia , Masculino , Camundongos
9.
Tumour Biol ; 37(10): 13499-13508, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27465555

RESUMO

Hepatocellular carcinoma (HCC) and hepatic cholangiocarcinoma (CC) are the most aggressive malignancies with a poor prognosis in humans, and hepatic cholangiocarcinoma (CC) exhibits greater malignant behaviour. Yes-associated protein (YAP) is an important downstream target of the Hippo signalling pathway. As an oncogene, it plays a vital role in the occurrence and development of tumours. Our study focuses on the clinical significance of YAP protein expression in HCC and CC. Furthermore, we sought to explore the different survival rates between HCC and CC. A total of 137 patients with HCC and 122 with CC after resection were evaluated by immunohistochemistry for the expression of YAP. Our results showed that positive expression rates of YAP were more frequently noted in CC 67.2 % (82/122) than in HCC 56.9 % (78/137) (P = 0.024). High YAP expression in HCC and CC was significantly associated with tumour size (P < 0.001 and P = 0.019, respectively), liver cirrhosis (P = 0.002 and P = 0.009, respectively), vascular invasion (P = 0.047 and P = 0.018, respectively), multiplicity (P = 0.019 and P = 0.015, respectively), and intrahepatic metastasis (P = 0.015 and P = 0.047, respectively). Importantly, recurrence-free survival and disease-specific survival rates were lower in CC with high YAP expression than in HCC with high YAP expression (P < 0.001 and P < 0.001, respectively). Overall, high YAP expression was more frequently found in CC than in HCC, and YAP overexpression was associated with poor survival rates in patients with HCC and CC. Targeting YAP treatment requires further prospective investigations in larger patient populations.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Carcinoma Hepatocelular/secundário , Colangiocarcinoma/patologia , Neoplasias Hepáticas/patologia , Recidiva Local de Neoplasia/patologia , Fosfoproteínas/metabolismo , Neoplasias dos Ductos Biliares/metabolismo , Neoplasias dos Ductos Biliares/patologia , Neoplasias dos Ductos Biliares/cirurgia , Ductos Biliares Intra-Hepáticos/metabolismo , Ductos Biliares Intra-Hepáticos/patologia , Ductos Biliares Intra-Hepáticos/cirurgia , Biomarcadores Tumorais/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/cirurgia , Colangiocarcinoma/metabolismo , Colangiocarcinoma/cirurgia , Terapia Combinada , Feminino , Seguimentos , Humanos , Técnicas Imunoenzimáticas , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/cirurgia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/cirurgia , Estadiamento de Neoplasias , Prognóstico , Transdução de Sinais , Taxa de Sobrevida , Fatores de Transcrição , Proteínas de Sinalização YAP
10.
ISA Trans ; 59: 172-9, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26350796

RESUMO

The optimal tracking performance of multiple-input multiple-output (MIMO) discrete-time networked control systems with bandwidth and coding constraints is studied in this paper. The optimal tracking performance of networked control system is obtained by using spectral factorization technique and partial fraction. The obtained results demonstrate that the optimal performance is influenced by the directions and locations of the nonminimum phase zeros and unstable poles of the given plant. In addition to that, the characters of the reference signal, encoding, the bandwidth and additive white Gaussian noise (AWGN) of the communication channel are also closely influenced by the optimal tracking performance. Some typical examples are given to illustrate the theoretical results.

11.
ISA Trans ; 58: 214-21, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26112929

RESUMO

The optimal tracking performance of single-input single-output (SISO) discrete-time networked control systems (NCSs) with the packet dropouts and channel noise is studied in this paper. The communication channel is characterized by three parameters: the packet dropouts, channel noise and the encoding and decoding. The explicit expression of the optimal tracking performance is obtained by using the spectral factorization. It is shown that the optimal tracking performance dependents on the nonminimum phase zeros, unstable poles of the given plant, as well as the packet dropout probability, channel noise and the encoding and decoding. The optimal tracking performance is improved by two-parameter compensator. Finally, a typical example is given to illustrate the theoretical results.

12.
ISA Trans ; 53(2): 251-7, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24161687

RESUMO

In this paper, the optimal tracking and regulation performance of discrete-time, multi-input multi-output, linear time-invariant systems is investigated. The control signal is influenced by the external disturbance, and the output feedback is subjected to an additive white Gaussian noise (AWGN) corruption. The tracking error with channel input power constraint and the output regulation with control energy constraint are adopted as the measure of tracking and regulation performance respectively, which can be obtained by searching through all stabilizing two-parameter controllers. Both results demonstrate that the performance is closely related to locations and directions of the nonminimum phase zeros, unstable poles of the plant and may be badly degraded by external disturbance and AWGN.

13.
Huan Jing Ke Xue ; 35(11): 4387-94, 2014 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-25639121

RESUMO

Shifting path of industrial pollution gravity centers is the response of environmental special formation during the industry transfer process, in order to prove the responding of industrial pollution gravity centers to industry transfer in economically developed areas, this paper calculates the gravity centers of industrial wastewater, gas and solid patterns and reveals the shifting path and its driving mechanism, using the data of industrial pollution in the Pan-Yangtze River Delta from 2000 to 2010. The results show that the gravity center of the industrial waste in Pan-Yangtze River Delta shifts for sure in the last 10 years, and gravity center of solid waste shifts the maximum distance within the three wastes, which was 180.18 km, and shifting distances for waste gas and waste water were 109.51 km and 85.92 km respectively. Moreover, the gravity center of the industrial waste in Pan-Yangtze River Delta shifts westwards, and gravity centers of waste water, gas and solid shift for 0.40 degrees, 0.17 degrees and 0.03 degrees respectively. The shifting of industrial pollution gravity centers is driven by many factors. The rapid development of the heavy industry in Anhui and Jiangxi provinces results in the westward shifting of the pollutions. The optimization and adjustment of industrial structures in Yangtze River Delta region benefit to alleviating industrial pollution, and high-polluting industries shifted to Anhui and Jiangxi provinces promotes pollution gravity center shifting to west. While the development of massive clean enterprise, strong environmental management efforts and better environmental monitoring system slow the shifting trend of industrial pollution to the east in Yangtze River Delta. The study of industrial pollution gravity shift and its driving mechanism provides a new angle of view to analyze the relationship between economic development and environmental pollution, and also provides academic basis for synthetical management and control of environmental pollution in Pan-Yangtze River Delta, especially in the transition period.


Assuntos
Monitoramento Ambiental , Resíduos Industriais , China , Geografia , Indústrias/tendências , Rios , Águas Residuárias , Poluentes Químicos da Água
14.
J Surg Res ; 184(2): 1035-44, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23721934

RESUMO

BACKGROUND/AIMS: Endotoxin (lipopolysaccharide, LPS)-induced acute liver injury was attenuated by endotoxin tolerance (ET), which is characterized by phosphatidylinositol 3-kinase pathway/Akt signaling. Glycogen synthase kinase 3 (GSK-3) acts downstream of phosphatidylinositol 3-kinase pathway/Akt and GSK-3 inhibitor protects against organic injury. This study evaluates the hypothesis that ET attenuated LPS-induced liver injury through inhibiting GSK-3 functional activity and downstream signaling. METHODS: Sprague-Dawley rats with or without low-dose LPS pretreatment were challenged with or without large dose of LPS and subsequently received studies. Serum tumor necrosis factor-alpha, interleukin-10, alanine aminotransferase, lactate dehydrogenase, and total bilirubin levels were analyzed, morphology of liver tissue was performed, glycogen content, myeloperoxidase content, phagocytosis activity of Kupffer cells, and the expression and inhibitory phosphorylation as well as kinase activity of GSK-3 were examined. Survival after LPS administration was also determined. RESULTS: LPS induced significant increases of serum TNF-α, alanine aminotransferase, lactate dehydrogenase, and total bilirubin (P < 0.05), which were companied by obvious alterations in liver: the injury of liver tissue, the decrease of glycogen, the infiltration of neutrophils, and the enhancement of phagocytosis of Kupffer cells (P < 0.05). LPS pretreatment significantly attenuated these alterations, promoted the inhibitory phosphorylation of GSK-3 and inhibited its kinase activity, and improved the survival rate (P < 0.05). CONCLUSIONS: ET attenuated LPS-induced acute liver injury through inhibiting GSK-3 functional activity and its downstream signaling.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Endotoxinas/efeitos adversos , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Lipopolissacarídeos/efeitos adversos , Transdução de Sinais/efeitos dos fármacos , Alanina Transaminase/metabolismo , Animais , Bilirrubina/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Quinase 3 da Glicogênio Sintase/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase/metabolismo , Interleucina-10/metabolismo , L-Lactato Desidrogenase/metabolismo , Masculino , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/metabolismo
15.
Biochem Biophys Res Commun ; 433(2): 200-6, 2013 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-23466354

RESUMO

Long noncoding RNAs (lncRNAs) are pervasively transcribed and have a critical role in genome regulation. Alterations in the expression of several lncRNAs have been observed in some types of cancers; however, the contributions of lncRNAs to osteosarcoma remain unknown. Here, we describe the expression profile of lncRNAs in osteosarcomas compared with paired adjacent noncancerous tissue using microarray analysis. In our study, 25,733 lncRNAs were expressed in osteosarcoma; 403 lncRNAs were consistently over-regulated and 798 lncRNAs were consistently under-regulated in all samples analyzed (⩾2.0-fold, p<0.05). Quantitative real-time polymerase chain reaction (PCR) was used to validate six over-regulated and four under-regulated lncRNAs. Bioinformatic analysis (gene ontology analysis, pathway analysis and network analysis) was used for further research. Pathway analysis indicated that 32 pathways corresponded to under-regulated transcripts and that 34 pathways corresponded to over-regulated transcripts (p-value cut-off is 0.05). Our results are the first to reveal differentially expressed lncRNAs in osteosarcoma and suggest that lncRNAs may be novel candidate biomarkers for the diagnosis of osteosarcoma and potential targets for therapy.


Assuntos
Neoplasias Ósseas/genética , Osteossarcoma/genética , RNA Longo não Codificante , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , RNA Mensageiro , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...