Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Sci Rep ; 12(1): 10702, 2022 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-35739210

RESUMO

The reasonable layout of green infrastructure is conducive to the low-carbon, livable and high-quality sustainable development of cities. The framework of spatio-temporal evolution characteristics and prediction analysis of Urban Green Infrastructure (UGI) was constructed by integrating morphological spatial pattern analysis (MSPA) and CA-Markov in the study. We analyzed the spatio-temporal evolution characteristics of UGI in Beijing from 1990 to 2019, predicted its future change trend in 2030, and put forward the optimization scheme for the ecological network of UGI. The area change of UGI presented a "V" shape from 1990 to 2019 in Beijing, and the turning point was around 2009. Its spatial distribution revealed a significant heterogeneity. The comprehensive change rate index showed a "rising and then falling" trend from 1990 to 2019. Core with an area of over 1000 km2 had inclined "C" shape, connecting the north, west and south of the study area. Among the three prediction scenarios for 2030, the area of UGI under the ecological conservation priority scenario is the largest, accounting for 86.35% of the total area. The area of UGI under the economic development priority scenario is the smallest, accounting for 76.85%. The optimization of zoning and road network are effective measures to improve the connectivity of UGI in Beijing. This study is beneficial to extend the research ideas of UGI and promote sustainable urban development.


Assuntos
Planejamento de Cidades , Conservação dos Recursos Naturais , Pequim , China , Cidades , Ecossistema , Análise Espaço-Temporal
2.
iScience ; 25(5): 104321, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35602951

RESUMO

This review discusses physical, chemical, and direct lithium-ion battery recycling methods to have an outlook on future recovery routes. Physical and chemical processes are employed to treat cathode active materials which are the greatest cost contributor in the production of lithium batteries. Direct recycling processes maintain the original chemical structure and process value of battery materials by recovering and reusing them directly. Mechanical separation is essential to liberate cathode materials that are concentrated in the finer size region. However, currently, the cathode active materials are being concentrated at a cut point that is considerably greater than the actual size found in spent batteries. Effective physical methods reduce the cost of subsequent chemical treatment and thereafter re-lithiation successfully reintroduces lithium into spent cathodes. Some of the current challenges are the difficulty in controlling impurities in recovered products and ensuring that the entire recycling process is more sustainable.

3.
ACS Omega ; 6(33): 21586-21594, 2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34471762

RESUMO

The quantitative calculation of emulsified water fractions of crude oil-water systems is of great significance for the study of flow characteristics of multiphase flow pipelines. For a crude oil-water system with a high water fraction, the emulsified water fraction under different influencing factors was determined by emulsification experiments. It was found that the emulsified water fraction under different shearing conditions correlated well with the exergy loss rate and could be described by a power-law equation, in which two undetermined parameters relate to the crude oil physicochemical properties. Six representative parameters were selected to describe the crude oil physicochemical properties, i.e., the sum of asphaltene and resin contents, wax content, mechanical impurity content, crude oil acid number, crude oil average carbon number, and crude oil viscosity. Further, the correlations between the two undetermined parameters and the crude oil physicochemical properties were derived by regression analysis. Thus, the prediction model of emulsified water fraction was determined, which could be conveniently adopted to predict the emulsified water fraction with different crude oils and shearing conditions. The validation results showed that the mean relative deviation of the model prediction is 4.5%.

4.
Chaos Solitons Fractals ; 140: 110214, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32839643

RESUMO

The COVID-19 outbreak in late December 2019 is still spreading rapidly in many countries and regions around the world. It is thus urgent to predict the development and spread of the epidemic. In this paper, we have developed a forecasting model of COVID-19 by using a deep learning method with rolling update mechanism based on the epidemical data provided by Johns Hopkins University. First, as traditional epidemical models use the accumulative confirmed cases for training, it can only predict a rising trend of the epidemic and cannot predict when the epidemic will decline or end, an improved model is built based on long short-term memory (LSTM) with daily confirmed cases training set. Second, considering the existing forecasting model based on LSTM can only predict the epidemic trend within the next 30 days accurately, the rolling update mechanism is embedded with LSTM for long-term projections. Third, by introducing Diffusion Index (DI), the effectiveness of preventive measures like social isolation and lockdown on the spread of COVID-19 is analyzed in our novel research. The trends of the epidemic in 150 days ahead are modeled for Russia, Peru and Iran, three countries on different continents. Under our estimation, the current epidemic in Peru is predicted to continue until November 2020. The number of positive cases per day in Iran is expected to fall below 1000 by mid-November, with a gradual downward trend expected after several smaller peaks from July to September, while there will still be more than 2000 increase by early December in Russia. Moreover, our study highlights the importance of preventive measures which have been taken by the government, which shows that the strict controlment can significantly reduce the spread of COVID-19.

5.
Fertil Steril ; 109(5): 900-907, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29778389

RESUMO

OBJECTIVE: To evaluate the effects of resveratrol on oocyte maturation in aged mice and humans. DESIGN: Experimental laboratory study. SETTING: University-based reproductive medicine center. PATIENT(S): A total of 64 women 38-45 years of age undergoing intracytoplasmic sperm injection (ICSI) and 48-52-week-old female C57BL/6J mice. INTERVENTION(S): In vitro culture in the presence of three different concentrations of resveratrol (0.1, 1.0, and 10 µm) or dimethylsulfoxide. MAIN OUTCOME MEASURE(S): Parameters of oocyte nuclear maturation, fertilization, immunofluorescence intensity of mitochondria, and normal morphology of spindle and chromosome of oocytes undergoing in vitro maturation (IVM) in aged mice and humans; blastocyst formation and levels of SRIT1, CAT, SOD1, and GPX4 gene expressions in aged mice. RESULT(S): Resveratrol at 1.0 µm significantly increased first polar body emission rate in oocytes derived from aged mice and humans, and an increased percentage of fertilization and blastocyst formation was observed in aged mice. In addition, immunofluorescence intensity of mitochondria and normal morphology of spindle and chromosome of oocytes undergoing IVM were notably improved compared with control samples in aged mice and human. Furthermore, the use of resveratrol exhibited enhanced expression patterns of SRIT1, CAT, SOD1, and GPX4 in aged mice. CONCLUSION(S): Resveratrol induced oocyte maturation and blastocyst formation in aged mice, and improved oocyte maturation and quality was examined in aged humans. In conclusion, 1.0 µm resveratrol was the appropriate concentration in IVM medium.


Assuntos
Envelhecimento/efeitos dos fármacos , Antioxidantes/farmacologia , Técnicas de Maturação in Vitro de Oócitos/métodos , Oócitos/efeitos dos fármacos , Oócitos/crescimento & desenvolvimento , Resveratrol/farmacologia , Adulto , Envelhecimento/fisiologia , Animais , Relação Dose-Resposta a Droga , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Indução da Ovulação/métodos
6.
Mol Med Rep ; 16(6): 7939-7948, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28983596

RESUMO

CDGSH iron sulfur domain 2 (CISD2) has been found to be important in carcinogenesis. However, the role of CISD2 in glioma remains to be elucidated. The present study aimed to investigate the role of CISD2 in glioma using the reverse transcription­quantitative polymerase chain reaction, western blotting, co­immunoprecipitation assay, immunofluorescence staining and other methods. The results demonstrated that the mRNA and protein levels of CISD2 were found to be upregulated in glioma tissues, compared with the levels in matched normal tissues. Clinical data analysis showed that the level of CISD2 was negatively correlated with the survival rates of patients with glioma. In addition, high levels of CISD2 were associated with advanced clinical stage, relapse, vascular invasion and increased tumor size. The inhibition of CISD2 suppressed the proliferation and survival of glioma cells in vitro and in vivo. Mechanistically, it was found that small interfering RNA­induced knock down of CISD2 inhibited the proliferation of glioma cells through activating beclin­1­mediated autophagy. The results also revealed that CISD2 was a target of microRNA (miR)­449a. Together, the results of the present study demonstrated that CISD2 was increased in glioma samples and was associated with poor prognosis and aggressive tumor behavior. The miR­449a/CISD2/beclin­1­mediated autophagy regulatory network contributed to the proliferation of glioma cells. Targeting this pathway may be a promising strategy for glioma therapy.


Assuntos
Autofagia/genética , Proteína Beclina-1/genética , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Glioma/metabolismo , Proteínas de Membrana/metabolismo , MicroRNAs/genética , Interferência de RNA , Adulto , Idoso , Animais , Proteína Beclina-1/metabolismo , Biomarcadores Tumorais , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular/genética , Modelos Animais de Doenças , Feminino , Inativação Gênica , Glioma/mortalidade , Glioma/patologia , Xenoenxertos , Humanos , Masculino , Proteínas de Membrana/genética , Camundongos , Pessoa de Meia-Idade , Modelos Biológicos , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , Carga Tumoral
7.
Oncotarget ; 7(35): 57099-57116, 2016 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-27494859

RESUMO

Hepatic stellate cells (HSCs) induce immune privilege and promote hepatocellular carcinoma (HCC) by suppressing the immune system. On the other hand, galectin-1 and miRNA-22 (miR-22) are dysregulated in HCC and serve as prognostic indicators for patients. In this study, therefore, we measured galectin-1 and miR-22 expression in HSCs isolated from HCC tissues (Ca-HSCs), and in normal liver tissues (N-HSCs) as a control. We also investigated the apoptosis rate among T cells and the production of cytokines (IFN-γ and IL-10) in HSCs co-cultured with T cells. And we used immunohistochemical staining to tested for correlation between galectin-1 expression, CD3 expression and clinicopathological features in 162 HCC patients. Our results showed that galectin-1 expression was much higher in Ca-HSCs than in N-HSCs. Overexpression of galectin-1 promoted HSC-induced T cell apoptosis and cytokine production (IFN-γ and IL-10), while miR-22 expression inhibited it. Galectin-1 expression correlated negatively with miR-22 expression in HSCs. High galectin-1 and low CD3 expression levels were associated with poor prognosis in HCC patients. These results suggest that the immunosuppressive microenvironment promoted by HSC-derived galectin-1 in HCC can be inhibited by miR-22. Galectin-1 and miR-22 could potentially serve as prognostic markers and therapeutic targets in HCC.


Assuntos
Carcinoma Hepatocelular/metabolismo , Galectina 1/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/metabolismo , MicroRNAs/metabolismo , Actinas/metabolismo , Idoso , Apoptose , Complexo CD3/metabolismo , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Citocinas/metabolismo , Feminino , Galectina 1/genética , Perfilação da Expressão Gênica , Humanos , Interferons/metabolismo , Interleucina-10/metabolismo , Células K562 , Fígado/metabolismo , Neoplasias Hepáticas/genética , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Prognóstico , Linfócitos T/metabolismo
8.
Asian Pac J Trop Med ; 7(12): 1000-4, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25479631

RESUMO

OBJECTIVE: To investigate the expression of miR-218 and its clinical significance in osteosarcoma tissues and explore its effect on proliferation and apoptosis in osteosarcoma cells. METHODS: miR-218 expression was detected in 76 samples of surgically resected osteosarcoma and matched normal tumor-adjacent tissues using quantitative reverse transcription polymerase chain reaction (qRT-PCR). MiR-218 was over-expressed by exogenous miR-218 plasmids in Saos-2 cells, and then BrdU cell proliferation assay and flow cytometry were used to determine cell proliferation and apoptosis. RESULTS: The expression of miR-218 in osteosarcoma tissues was significantly lower than those in normal tumor-adjacent tissues (t=8.735, P<0.001). MiR-218 expression in tumor tissues was significantly correlated with tumor size (χ(2)=5.380, P=0.020), clinical stage (χ(2)=6.692, P=0.010) and distant metastasis (χ(2)=4.180, P=0.041). MiR-218 was obviously over-expressed by exogenous miR-218 plasmids (t=19.42, P<0.001), and miR-218 overexpression significantly reduced cell proliferation (t=9.045, P<0.001) and induced apoptosis (t=12.38, P<0.001) in Saos-2 cells. CONCLUSIONS: The low-expression of miR-218 is correlated with the poor clinicopathological features in osteosarcoma. Moreover, miR-218 overexpression reduces cancer cell proliferation and induces apoptosis in Saos-2 cells, suggesting that miR-218 may play a key role in the progression of human osteosarcoma.

9.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-820118

RESUMO

OBJECTIVE@#To investigate the expression of miR-218 and its clinical significance in osteosarcoma tissues and explore its effect on proliferation and apoptosis in osteosarcoma cells.@*METHODS@#miR-218 expression was detected in 76 samples of surgically resected osteosarcoma and matched normal tumor-adjacent tissues using quantitative reverse transcription polymerase chain reaction (qRT-PCR). MiR-218 was over-expressed by exogenous miR-218 plasmids in Saos-2 cells, and then BrdU cell proliferation assay and flow cytometry were used to determine cell proliferation and apoptosis.@*RESULTS@#The expression of miR-218 in osteosarcoma tissues was significantly lower than those in normal tumor-adjacent tissues (t=8.735, P<0.001). MiR-218 expression in tumor tissues was significantly correlated with tumor size (χ(2)=5.380, P=0.020), clinical stage (χ(2)=6.692, P=0.010) and distant metastasis (χ(2)=4.180, P=0.041). MiR-218 was obviously over-expressed by exogenous miR-218 plasmids (t=19.42, P<0.001), and miR-218 overexpression significantly reduced cell proliferation (t=9.045, P<0.001) and induced apoptosis (t=12.38, P<0.001) in Saos-2 cells.@*CONCLUSIONS@#The low-expression of miR-218 is correlated with the poor clinicopathological features in osteosarcoma. Moreover, miR-218 overexpression reduces cancer cell proliferation and induces apoptosis in Saos-2 cells, suggesting that miR-218 may play a key role in the progression of human osteosarcoma.

10.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-951813

RESUMO

Objective: To investigate the expression of miR-218 and its clinical significance in osteosarcoma tissues and explore its effect on proliferation and apoptosis in osteosarcoma cells. Methods: miR-218 expression was detected in 76 samples of surgically resected osteosarcoma and matched normal tumor-adjacent tissues using quantitative reverse transcription polymerase chain reaction (qRT-PCR). MiR-218 was over-expressed by exogenous miR-218 plasmids in Saos-2 cells, and then BrdU cell proliferation assay and flow cytometry were used to determine cell proliferation and apoptosis. Results: The expression of miR-218 in osteosarcoma tissues was significantly lower than those in normal tumor-adjacent tissues (t=8.735, P<0.001). MiR-218 expression in tumor tissues was significantly correlated with tumor size (χ

11.
Huan Jing Ke Xue ; 30(2): 362-7, 2009 Feb 15.
Artigo em Chinês | MEDLINE | ID: mdl-19402482

RESUMO

Rainwater samples were colleted from Lijiang City, China, in 23 May-2 July, 2006. Rainwater chemical compositions and sources were studied, using HYSPLIT model, ions tracer techniques, correlation and trend analysis. Total ionic concentration was dominated by SO4(2-) and Ca2+, which account for 65.5% and 15.6% respectively. Sort order of ions concentration is SO4(2-) > Ca2+ > Cl(-) > NO3(-) > Na+ > K+ > Mg2+. Total anions concentration is higher than total cations concentration in 13 rainwater events. The ratio of SO4(2-) to NO3(-) varies from 7.2 to 37.1 and average value is 15.7, it reflected SO4(2-) made great contribution to rainwater acidity in Lijiang City. The correlation among ions is significant due to the atmospheric chemical process and similar ionic sources, and correlation coefficient between SO4(2-) and NO3(-) is 0.74. And what's more, the negative correlation of ionic concentration, precipitation and the average wind speed is also outstanding. The source of NO3(-), SO4(2-), K+ and Ca2+ is mainly land dust, and the non-marine source percent of NO3(-), SO4(2-), K+, Ca2+, Mg2+ and Cl(-) is 100%, 98.8%, 96%, 99.3%, 46.7% and 50.3%, respectively. The main reason of atmospheric environmental variation in Lijing City is pollution caused by economic actions. The pollutants from surrounding industrial parks input into Lijiang City by local circulation, and from industrial regions of Southern Asia, Southeastern Asia and Southeastern China input into Lijiang City by monsoonal circulation.


Assuntos
Chuva Ácida/análise , Poluentes Atmosféricos/análise , Nitratos/análise , Chuva/química , Dióxido de Enxofre/análise , Cálcio/análise , China , Estações do Ano
12.
World J Gastroenterol ; 10(6): 885-8, 2004 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-15040038

RESUMO

AIM: To evaluate the local expression of CTLA4Ig gene in small bowels and its effect on preventing acute rejection of the small bowel allografts. METHODS: Groups of Wistar rats underwent heterotopic small bowel transplantation from SD rats. The recipients were randomly divided into experimental group (allografts were transfected with CTLA4Ig gene) and control group (non CTLA4Ig gene transfected). In the experimental group, the donor small bowels were perfused ex vivo with CTLA4Ig cDNA packaged with lipofectin vector via intra-superior mesenteric artery before transplantation, and the CTLA4Ig expression in the small bowel grafts post-transplantation was assessed by immunohistology. On d 3, 7 and 10 post-transplantation, the allografts in each group were harvested for the examination of histology and detection of apoptosis. RESULTS: Small bowel allografts treated with CTLA4Ig cDNA showed abundant CTLA4Ig expression after transplantation. Acute rejection of grade I on d 7 and grade II on d 10 after transplantation was noticed in the control allografts, and a dramatically increased number of apoptotic enterocytes in parallel to the progressive rejection could be recognized. In contrast, the allografts treated with CTLA4Ig cDNA showed nonspecific histological changes and only a few apoptotic enterocytes were found after transplantation. CONCLUSION: Local CTLA4Ig gene transfection of small bowel allograft is feasible, and the local CTLA4Ig expression in the allograft can prevent acute rejection after transplantation.


Assuntos
Rejeição de Enxerto/prevenção & controle , Imunoconjugados/genética , Intestino Delgado/transplante , Transfecção , Abatacepte , Doença Aguda , Animais , Masculino , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Transplante Heterotópico , Transplante Homólogo
13.
J Neurotrauma ; 20(8): 755-65, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12965054

RESUMO

Prosaposin, the precursor of saposins or saps, is an injury-repair protein that acts on both neurons and glia. Previous studies identified the prosaposin gene as one of differentially expressed genes following nerve injury. In the present study, we investigated expression of prosaposin mRNA in injured brain utilizing rat models of focal cerebral ischemia and cortical stab wound in order to explore the significance of prosaposin in nerve injury. In ischemic brain, the level of prosaposin mRNA was elevated greater than 400% over controls within 5 days after ischemic insults. Importantly, this induction was accompanied by a 9-base splicing consistent with the alternative Exon-8 splicing of human prosaposin mRNA. In normal brain, two prosaposin mRNA species with and without the 9-base insertion were expressed at a ratio of 85:15; however, this equilibrium reverted to 5:95 following ischemic injury. Similar inductions were observed in stab wound brains. Immunohistochemical staining and in situ hybridization demonstrated an enhanced signal distribution of prosaposin mRNA and injury-induced prosaposin protein around the lesion. The data suggest the expression and processing of prosaposin mRNA may be crucially regulated not only for cerebral homeostasis but also during nerve regenerative and degenerative processes.


Assuntos
Lesões Encefálicas/genética , Regulação da Expressão Gênica , Glicoproteínas/biossíntese , RNA Mensageiro/genética , Processamento Alternativo/genética , Animais , Northern Blotting , Lesões Encefálicas/metabolismo , Éxons/genética , Biblioteca Gênica , Imuno-Histoquímica , Hibridização In Situ , Masculino , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Saposinas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...