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生长/分化因子MK家族的生物学作用的研究进展
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作者 黄郁霆 《大自然探索》 1997年第2期68-73,共6页
孕中期肾蛋白(Midkine,MK)和多效生长因子(Pleiotrophin,PTN)组成一种新的肝素结合生长/分化因子家族。它们都是分泌性单肽链蛋白,蛋白质结构都类似。MK和PTN基因均可在胚胎发育期在多种组织大量... 孕中期肾蛋白(Midkine,MK)和多效生长因子(Pleiotrophin,PTN)组成一种新的肝素结合生长/分化因子家族。它们都是分泌性单肽链蛋白,蛋白质结构都类似。MK和PTN基因均可在胚胎发育期在多种组织大量表达,而仅PTN在出生后,有一种神经系统的短暂表达高峰,两者不同地见于数种成年期组织。这些发现结合体外实验结果,提示它们在发育上有重要的促生长/分化作用,并具有神经营养活性,在成年期也有某些未知的生理功能。其中,尤以对神经系统的发育和维持最为重要。它们还可促进血管内皮细胞的纤溶活性。 展开更多
关键词 孕中期肾蛋白 多效生长因子 生长/分化 神经营养活性 纤溶活性 肿瘤生长
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肌腱组织工程和基因转染 被引量:2
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作者 黄德清 冯燕茹 《中国矫形外科杂志》 CAS CSCD 北大核心 2009年第12期909-911,共3页
骨髓源间充质干细胞是肌腱组织工程最为常用的种子细胞。脂肪源干细胞具备相似的多分化潜能,有望成为肌腱组织工程的种子细胞。纳米纤维材料可以模拟细胞外基质的结构和功能,作为肌腱组织工程的支架有明显的优越性。基因转染技术可克服... 骨髓源间充质干细胞是肌腱组织工程最为常用的种子细胞。脂肪源干细胞具备相似的多分化潜能,有望成为肌腱组织工程的种子细胞。纳米纤维材料可以模拟细胞外基质的结构和功能,作为肌腱组织工程的支架有明显的优越性。基因转染技术可克服外源性细胞因子在肌腱修复处作用短暂的不足。肌腱组织工程及基因转染的前景令人鼓舞,但仍面临诸多挑战,需进一步研究。 展开更多
关键词 肌腱损伤 修复和再生 间充质细胞 生长/分化 组织工程 基因治疗
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脑梗死患者血清CXCL-16、GDF-15、PLA2水平变化及意义 被引量:7
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作者 刘希奇 李孝庆 +1 位作者 姚彦 崔亚男 《中国现代医学杂志》 CAS 2019年第15期36-40,共5页
目的 研究脑梗死患者的血清CXC趋化因子16(CXCL-16)、血清生长分化因子15(GDF-15)、脂蛋白相关磷脂酶A2(PLA2)的水平变化及对脑梗死患者临床诊治的指导意义.方法 选取2016年6月—2017年6月沧州市中心医院98例脑梗死患者为观察组,同期该... 目的 研究脑梗死患者的血清CXC趋化因子16(CXCL-16)、血清生长分化因子15(GDF-15)、脂蛋白相关磷脂酶A2(PLA2)的水平变化及对脑梗死患者临床诊治的指导意义.方法 选取2016年6月—2017年6月沧州市中心医院98例脑梗死患者为观察组,同期该院进行体检的50例健康志愿者作为对照组.所有受试者于入院时抽血检测各组的CXCL-16、GDF-15、PLA2、C反应蛋白(CRP)水平,综合评价脑梗死患者各项指标的水平变化及对临床诊断的意义.结果 ①观察组患者的CXCL-16、GDF-15、PLA2、CRP水平与对照组比较,差异有统计学意义(P<0.05).②将观察组患者按美国国立卫生院神经功能缺损评分(NIHSS)分组,患者的CXCL16、GDF-15、PLA2水平随着NIHSS分值的增加而升高,组间比较,差异有统计学意义(P<0.05),而各组间的CRP水平差异无统计学意义(P>0.05).③将患者按病灶大小分组,患者的CXCL16、GDF-15、PLA2水平随病灶的增大而升高(P<0.05),而各组间的CRP水平差异无统计学意义(P>0.05).④观察组患者治疗后出院时的CXCL-16、GDF-15、PLA2、CRP水平与对照组比较,差异无统计学意义(P>0.05),观察组患者的这些指标水平降至正常水平.结论 CXCL-16、GDF-15、PLA2水平随患者病情程度的变化而改变,可作为预测脑梗死患者发病、病情评估及判断预后的生物学标志物. 展开更多
关键词 脑梗死/脑梗塞 血清CXC趋化因子16/趋化因子类 生长/分化因子-15 磷脂酶A
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高原先天性心脏病与gdf1基因突变的分子流行病学研究 被引量:4
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作者 刘世明 杜悦新 +4 位作者 王晶 吴施楠 裴金莲 王彬彬 陈秋红 《中国计划生育学杂志》 2015年第8期530-533,共4页
目的:研究青海高原地区先天性心脏病(CHD)患者生长/分化因子1(gdf1)基因错义突变的情况,探讨CHD和gdf1基因之间可能的潜在关联。方法:分别收集100例散发型CHD患者和正常健康对照对象的血液,利用PCR扩增gdf1基因全部编码外显子及其周围序... 目的:研究青海高原地区先天性心脏病(CHD)患者生长/分化因子1(gdf1)基因错义突变的情况,探讨CHD和gdf1基因之间可能的潜在关联。方法:分别收集100例散发型CHD患者和正常健康对照对象的血液,利用PCR扩增gdf1基因全部编码外显子及其周围序列,对PCR产物直接测序,进行突变检测,并与GeneBank数据库进行比较得到突变位点,然后进行生物信息学分析。结果:在一名藏族室间隔缺损(VSD)患者中发现了gdf1基因的1个新的错义突变c.489G>A(p.W163C),该突变位于gdf1成熟蛋白前体区域。结论:在青海高原地区先心病患者中发现了gdf1基因的错义突变,表明gdf1基因突变可能与高原地区先天性心脏缺陷中的VSD发生相关。 展开更多
关键词 高原 先天性心脏病 生长/分化因子基因 突变 室间隔缺损
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Growth Differentiation Factor-9 Gene Expression of Mice Oocytes in Vitro and in Vivo 被引量:5
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作者 彭宇洪 庄广伦 +2 位作者 周灿权 谢守珍 程冀平 《Zoological Research》 CAS CSCD 北大核心 2006年第5期456-460,共5页
Mice preantral follicles were cultured in vitro for 12 days to achieve metaphase Ⅱ (M Ⅱ ) oocytes. Oocyte growth differentiation factor-9 (GDF-9) gene expression was measured during different growth stages to ex... Mice preantral follicles were cultured in vitro for 12 days to achieve metaphase Ⅱ (M Ⅱ ) oocytes. Oocyte growth differentiation factor-9 (GDF-9) gene expression was measured during different growth stages to explore the relationship between oocyte maturation and GDF-9 gene expression. Preantral follicles of lO-day old mice were isolated from the ovaries and were cultured for 12 days. Oocytes from day 2 (D2), D4, D6, D8, DIO, D12 cultured in vitro were named the in vitro group and oocytes of day 12 (D12), D14, D16, D18, D20, D22 grown in vivo were named the in vivo group. Follicle survival, antrum formation and maturation rate were 89.5%, 51.8% and 56.6% respectively in follicles cultured in vitro. After RT-PCR and agarose gel electrophoresis, relative mRNA abundance of GDF-9 was measured in each group of oocytes. At day 8 - 12, the GDF-9 gene expression level of oocytes in vitro was significantly lower than that in vivo (P 〈 0.05). We conclude that M Ⅱ oocytes can be obtained from in vitro culture of preantral follicles. The GDF- 9 gene expression of oocytes varies at different growth stages in vivo. The low expression of GDF-9 in oocytes cuhured in vitro may be the cause of their low developmental capacity. 展开更多
关键词 MICE CULTURE OOCYTE Growth differention factor-9
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RELATIONSHIP BETWEEN GROWTH AND MORPHOLOGY OF METARRHIZIUM ANISOPLIAE IN BIOTRANSFORMATION OF STEROID 被引量:2
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作者 阳葵 李晓静 +2 位作者 王积分 段世铎 张鎏 《Transactions of Tianjin University》 EI CAS 2001年第1期1-6,共6页
The fermentation with mold metarrhizium anisopliae has been carried out to determine the relationship between mycelial morphology and growth.Like the biomass concentration,the mycelial morphology seems to be coupled t... The fermentation with mold metarrhizium anisopliae has been carried out to determine the relationship between mycelial morphology and growth.Like the biomass concentration,the mycelial morphology seems to be coupled to growth phases:the fractal dimension,a feature calculated from the morphological images,increases during the late lag phase and the early exponential phase,and culminates at a value near 2.4 at half of the exponential phase.This can be attributed to the marked change of rough and smooth pellet proportions during growth and the change can be well expressed by the fractal analysis of mycelial morphology.The mycelial morphology is also strongly related to the biotransformation activity:a mycelial sample was withdrawn from the culture to use for fractal analysis before the steroid substrate (16α,17α epoxy 4 pregnene 3,20 dione) was added;the higher fractal dimension corresponds to the higher conversion rate of steroid biotransformation.And the maximum of fractal dimension appeared prior to the maximum of biomass concentration.It is therefore possible to utilize the fractal dimension curve to supervise the fermentation process more timely and availably than to use the conventional biomass curve to do. 展开更多
关键词 metarrhizium anisopliae MORPHOLOGY GROWTH fractal dimension BIOTRANSFORMATION STEROID
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A Simplified Model with Soil Water Limitation on Spring Wheat Growth 被引量:2
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作者 郑海雷 米谷俊颜 黄子琛 《Acta Botanica Sinica》 CSCD 2000年第5期512-517,共6页
The authors constructed a simplified model of spring wheat (Triticum aestivum L.) carbon assimilation and dry matter accumulation (DMA) process which consisted of two independent variables, day length (L) and total... The authors constructed a simplified model of spring wheat (Triticum aestivum L.) carbon assimilation and dry matter accumulation (DMA) process which consisted of two independent variables, day length (L) and total daily radiation (TDR). Leaf water potential (Ψ) was incorporated into the simplified growth model based on the assumption that both light use efficiency (α) and CO 2 conductance of assimilation (g c) were depressed by water limitation. Finally,Ψ was estimated from a regression equation in which the independent variables were relative soil water content in the upper 80 cm (θ R,80 ), ambient temperature (T a), vapor pressure deficit (VPD), the cumulative leaf water potential below thresholds of -1.5 MPa (Ψ c,1.5 ). Some applications in research program of field experiment of atmosphere_land surface processes in Heihe River region were tested. The simulated data agreed well with the data observed at Linze oasis in 1989 for various levels of water supply and at Zhangye oasis in 1992 in the field. The analysis and simulation using the model demonstrated that the simplified growth model could describe very well the DMA process of spring wheat with and without water limitation in the region of HEIFE (Heihe field experiment). 展开更多
关键词 spring wheat GROWTH simplified model water limitation
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Variation Characteristics of Water Budget Condition of Heilongjiang Province in Recent 50 Years
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作者 李秀芬 姜丽霞 +1 位作者 王晾晾 李帅 《Agricultural Science & Technology》 CAS 2013年第2期361-368,392,共9页
Based on the 1961-2010 weather data from 65 meteorological stations in Heilongjiang Province, using the statistic software and GIS, the change characteristics of water budget, including the precipitation, reference ev... Based on the 1961-2010 weather data from 65 meteorological stations in Heilongjiang Province, using the statistic software and GIS, the change characteristics of water budget, including the precipitation, reference evapotranspiration and water budget in the whole year and the temperature-defined growing season, were analyzed. The results indicated that the both the precipitation during the whole year and that of during the temperature-defined growing season from 1961 to 2010 all decreased, while the annual reference evapotranspiration decreased, but the reference evapotranspiration during the temperature-defined growing season presented an increasing trend. The water resources were generally characterized by water deficit, especially in the beginning of 21 st . 展开更多
关键词 Heilongjiang Province Temperature-defined growing season Water bud- get Variation characteristics
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Response of seedlings of different tree species to elevated CO_2 in Changbai Mountain 被引量:1
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作者 王淼 李秋荣 +1 位作者 代力民 姬兰柱 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第2期112-116,共5页
Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadlea... Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadleaved/Korean pine forest, to elevated CO2 were studied by using open-top chambers under natural sunlight in Changbai Mountain, China in two growing seasons (1998-1999). Two concentrations of CO2 were designed: elevated CO2 (700 祄olmol-1) and ambient CO2 (400 祄olmol-1). The study results showed that the height growth of the tree seedlings grown at elevated CO2 increased by about 10%-40% compared to those grown at ambient CO2. And the water using efficiency of seedlings also followed the same tendency. However, the responses of seedlings in transpiration and chlorophyll content to elevated CO2 varied with tree species. The broad-leaf tree species were more sensitive to the elevated CO2 than conifer tree species. All seedlings showed a photosynthetic acclimation to long-term elevated CO2. 展开更多
关键词 Elevated CO_2 Eco-physiological response Changbai Mountain
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Novel biomarkers for cardiovascular risk prediction 被引量:21
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作者 Juan WANG Guo-Juan TAN +3 位作者 Li-Na HAN Yong-Yi BAI Miao HE Hong-Bin LIU 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2017年第2期135-150,共16页
Cardiovascular disease (CVD) is the leading cause of death and disability worldwide. The primary prevention of CVD is dependent upon the ability to identify high-risk individuals long before the development of overt... Cardiovascular disease (CVD) is the leading cause of death and disability worldwide. The primary prevention of CVD is dependent upon the ability to identify high-risk individuals long before the development of overt events. This highlights the need for accurate risk strati- fication. An increasing number of novel biomarkers have been identified to predict cardiovascular events. Biomarkers play a critical role in the definition, prognostication, and decision-making regarding the management of cardiovascular events. This review focuses on a variety of promising biomarkers that provide diagnostic and prognostic information. The myocardial tissue-specific biomarker cardiac troponin, high- sensitivity assays for cardiac troponin, and heart-type fatty acid binding proteinall help diagnose myocardial infarction (MI) in the early hours following symptoms. Inflammatory markers such as growth differentiation factor-15, high-sensitivity C-reactive protein, fibrinogen, and uric acid predict MI and death. Pregnancy-associated plasma protein A, myeloperoxidase, and matrix metalloproteinases predict the risk of acute cor- onary syndrome. Lipoprotein-associated phospholipase A2 and secretory phospholipase A2 predict incident and recurrent cardiovascular events. Finally, elevated natriuretic peptides, ST2, endothelin-1, mid-regional-pro-adrenomedullin, copeptin, and galectin-3 have all been well validated to predict death and heart failure following a MI and provide risk stratification information for heart failure. Rapidly develop- ing new areas, such as assessment ofmicro-RNA, are also explored. All the biomarkers reflect different aspects of the development ofather- osclerosis. 展开更多
关键词 BIOMARKER Cardiovascular disease PREDICTION Risk stratification
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Transforming growth factor-β1 induces intestinal myofibroblast differentiation and modulates their migration 被引量:12
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作者 Julia Brenmoehl Sandra Nicole Miller +4 位作者 Claudia Hofmann Daniela Vogl Werner Falk Jrgen Schlmerich Gerhard Rogler 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第12期1431-1442,共12页
AIM: To investigate the effects of transforming growth factor β1 (TGF-β1) on the differentiation of colonic lamina propria fibroblasts (CLPF) into myofibroblasts in vitro.METHODS: Primary CLPF cultures were in... AIM: To investigate the effects of transforming growth factor β1 (TGF-β1) on the differentiation of colonic lamina propria fibroblasts (CLPF) into myofibroblasts in vitro.METHODS: Primary CLPF cultures were incubated with TGF-β1 and analyzed for production of m-smooth muscle actin (α-SMA), fibronectin (FN) and FN isoforms. Migration assays were performed in a modified 48-well Boyden chamber. Levels of total and phosphorylated focal adhesion kinase (FAK) in CLPF were analyzed after induction of migration.did not change α-SMA levels, while TGF-β1 treatment for 6 d significantly increased α-SIVlA production. Short term incubation (6 h) with TGF-β1 enhanced CLPF migration, while long term treatment (6 d) of CLPF with TGF-β1 reduced migration to 15%-37% compared to untreated cells. FN and FN isoform mRNA expression were increased after short term incubation with TGF-β1 (2 d) in contrast to long term incubation with TGF-β1 for 6 d. After induction of migration, TGF-β1-preincubated CLPF showed higher amounts of FN and its isoforms and lower levels of total and phosphorylated FAK than untreated cells.CONCLUSION: Long term incubation of CLPF with TGF-β1 induced differentiation into myofibroblasts with enhanced α-SMA, reduced migratory potential and FAK phosphorylation, and increased FN production. In contrast, short term contact (6 h) of fibroblasts with TGF-β1 induced a dose-dependent increase of cell migration and FAK phosphorylation without induction of α-SMA production. 展开更多
关键词 Transforming growth factor β1 Colonicfibroblasts MYOFIBROBLASTS MIGRATION FIBRONECTIN
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Quantitative analysis of transforming growth factor beta 1 mRNA in patients with alcoholic liver disease 被引量:21
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作者 Wei-Xing Chen You-Ming Li Chao-Hui Yu Wei-Min Cai Min Zheng Feng-Chen,Department of Gastroenterology, The First Affiliated Hospital,Medical College of Zhejiang University,Hangzhou 310003,Zhejiang Province,China 《World Journal of Gastroenterology》 SCIE CAS CSCD 2002年第2期379-381,共3页
AIM: To investigate the expression of the transforming growth factor beta 1(TGF-beta 1) mRNA in different stages of alcoholic liver disease (ALD) and its clinical value. METHODS: One hundred and seven male alcoholics ... AIM: To investigate the expression of the transforming growth factor beta 1(TGF-beta 1) mRNA in different stages of alcoholic liver disease (ALD) and its clinical value. METHODS: One hundred and seven male alcoholics were grouped by clinical findings into four groups: alcohol abusers without liver impairment (n =22), alcoholic steatosis (n =30); alcoholic hepatitis (n=31); and alcoholic cirrhosis(n=24). Using peripheral blood mononuclear cells (PBMC) as samples the gene expression of TGF-beta 1 was examined quantitatively by reverse transcription polymerase chain reaction (RT-PCR) and dot blot. There are 34 healthy subjects served as control. RESULTS: The expression of TGF-beta 1 from all ALD patients was significantly greater than that in controls (1.320 +/- 1.162 vs 0.808 +/- 0.276, P【0.001). The differences of the expressions were significant between the patients from each groups (alcoholic steatosis, alcoholic hepatitis and alcoholic cirrhosis) and the controls (1.168 +/- 0.852, 1.462 +/- 1.657, 1.329 +/- 0.610 vs 0.808 +/- 0.276, P【0.050). No significant differences of TGF -beta 1 mRNA expression were observed between alcohol abusers without liver impairment and controls. The expressions in patients with alcoholic hepatitis and alcoholic cirrhosis were significantly greater than that in alcohol abusers respectively (1.462 +/- 1.657, 1.329 +/- 0.610 vs 0.841 +/- 0.706, P【0.050). No significant differences of TGF-beta 1 mRNA expression were observed between alcoholic fatty liver men and alcohol abusers. CONCLUSION: TGF-beta 1 expression level can be a risk factor for alcoholic liver disease and might be related to the inflammatory activity and fibrosis of the liver in patients. 展开更多
关键词 Humans Liver Diseases Alcoholic MALE RNA Messenger Transforming Growth Factor beta
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The auxin concentration in sixteen Chinese marine algae 被引量:1
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作者 韩丽君 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2006年第3期329-332,共4页
The author determined the occurrence of indole-3-acetic acid in sixteen Chinese marine algae collected from the east coast of China with fluorescence spectrophotometry (FS) and wheat coleop- tile bioanalysis methods (... The author determined the occurrence of indole-3-acetic acid in sixteen Chinese marine algae collected from the east coast of China with fluorescence spectrophotometry (FS) and wheat coleop- tile bioanalysis methods (WCB). The concentration of indole-3-acetic acid (IAA) presented was from 1.1–46.9 ng/g Fw (fresh weight) with FS and 5.3–110.2 ng/g Fw with WCB. The results by the two meth- ods were in the orders of 10-3–103 ng/g Fw reported previously from multiple references. 展开更多
关键词 marine algae fluorescence spectrophotometry coleoptile bioanalysis AUXIN indole-3-acetic acid
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STUDY ON THE INTERACTION BETWEEN NDVI PROFILE AND THE GROWING STATUS OF CROPS 被引量:16
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作者 JIANGDong WANGNai-bin +1 位作者 YANGXIao-huan WANGJi-hua 《Chinese Geographical Science》 SCIE CSCD 2003年第1期62-65,共4页
Daily and ten-day Normalized Difference Vegetation Index( NDVI) of crops were retrieved from meteorological satellite NOAA AVHRR images. The temporal variations of the NDVI were analyzed during the whole growing seaso... Daily and ten-day Normalized Difference Vegetation Index( NDVI) of crops were retrieved from meteorological satellite NOAA AVHRR images. The temporal variations of the NDVI were analyzed during the whole growing season, and thus the principle of the interaction between NDVI profile and the growing status of crops was discussed. As a case in point, the relationship between integral NDVI and winter wheat yield of Henan Province in 1999 had been analyzed. By putting integral NDVI values of 60 sample counties into the winter wheat yield-integral NDVI coordination, scattering map was plotted. It demonstrated that integral NDVI had a close relation with winter wheat yield. These relation could be described with linear, cubic polynomial, and exponential regression, and the cubic polynomial regression was the best way. In general, NDVI reflects growing status of green vegetation, so crop monitoring and crop yield estimation could be realized by using remote sensing technique on the basis of time serial NDVI data together with agriculture calendars. 展开更多
关键词 NDVI PROFILE growing status CROP
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Scale-up of NaA zeolite membranes on α-Al_2O_3 hollow fibers by a secondary growth method with vacuum seeding 被引量:4
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作者 刘艳梅 王学瑞 +2 位作者 张玉亭 何勇 顾学红 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第7期1114-1122,共9页
NaA zeolite membranes were prepared by secondary growth method on the outer surface of α-Al2O3 hollow fiber supports. Vacuum seeding method was used for planting zeolite seeds on the support surfaces. Hydrothermal cr... NaA zeolite membranes were prepared by secondary growth method on the outer surface of α-Al2O3 hollow fiber supports. Vacuum seeding method was used for planting zeolite seeds on the support surfaces. Hydrothermal crystallization was then carried out in a synthesis solution with molar ratio of Al2O3:SiO2:Na2O:H2O = 1:2:2:120 at 100 ℃ for 4 h. Effects of seeding conditions on preparation of hollow fiber NaA zeolite membranes were extensively investigated. Moreover, hollow fiber membrane modules with packing membrane areas of ca. 0.1 and 0.2 m2 were fabricated to separate ethanol/water mixture. It is found that the thickness of seed layer is obviously affected by seed suspension concentration, coating time and vacuum degree. Close-packing seed layer is required to obtain high-quality membranes. The optimized seeding conditions (seed suspension mass concentration of 0.5%-0.7% coating time of 5 s and vacuum degree of 10 kPa) lead to dense NaA zeolite layer with a thickness of 6-8 gin. Typically, an as-synthesized hollow fiber NaA zeolite membrane exhibits good pervaporation performance with a permeation flux of 7.02 kg· m^- 2· h^- 1 and separation factor 〉 10000 for sepa- ration of 90%; (by mass) ethanol/water mixture at 75 ℃ High reproducibility has been achieved for batch-scale production of hollow fiber NaA zeolite membranes by the hydrothermal synthesis approach. 展开更多
关键词 JNaA zeolite membraneVacuum seeding methodHollow fiberPervaporation
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Comparative Utilization of Different Fibre Feedstuffs by Weaning/Growing Pigs in the Tropics 被引量:2
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作者 Emmanuel Oluropo Akinfala Omotola Macaulay Samuel Temitope Ogundeji 《Journal of Agricultural Science and Technology(A)》 2014年第2期149-154,共6页
This study was conducted to investigate the effect of feeding different fibre feedstuffs on the performance, nutrient utilization and economics of production of weaning/growing pigs. Five fibre feedstuffs--palm kernel... This study was conducted to investigate the effect of feeding different fibre feedstuffs on the performance, nutrient utilization and economics of production of weaning/growing pigs. Five fibre feedstuffs--palm kernel cake (PKC), wheat offal (WO), corn bran (CB), rice bran (RB) and brewers' dried grain (BDG) were used at 25% in each of the five experimental diets that were formulated in this study. Twenty weaner pigs (12.75 ± 0.6 kg) were used for the growth study while 15 pigs (14.95 ± 0.57 kg) were used for the digestibility study. The design of the experiment was completely randomized. The results of the study showed that the performance of the experimental animals were significantly influenced (P 〈 0.05) by the dietary treatments. The apparent digestibility of the crude protein, crude fiber and ether extract showed significant differences (P 〈 0.05) while there was no significant difference (P 〉 0.05) in the apparent digestibility of their dry matter, ash and nitrogen free extract. The diet that contained WO had the best growth response and apparent nutrient digestibility. Results of economics of production also showed that diet with WO gave the best (P 〈 0.05) value in feed cost/'kg gain and net profit/animal. It can be concluded from this study that although all the animals fed the different fibre feedstuffs performed satisfactorily on all the parameters monitored, but for optimum growth, apparent nutrients digestibility and economics of production. WO should be used as a fibre feedstuff in the diets of weaning/growing pigs in the tropics. 展开更多
关键词 PIGS performance DIGESTIBILITY economics of production DIETS
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Fractal Evolving Theory and Growing Model of Olefin Polymerization Process 被引量:1
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作者 霍超 孟濬 +2 位作者 任晓红 阳永荣 戎顺熙 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第1期33-37,共5页
The surface morphology of Ti-Mg supported catalyst and the polyethyleneparticles are studied using scanning electron microscope(SEM) technology. The results show thateithen the catalyst's surface or polymer partic... The surface morphology of Ti-Mg supported catalyst and the polyethyleneparticles are studied using scanning electron microscope(SEM) technology. The results show thateithen the catalyst's surface or polymer particle's surface is irregular and has fractalcharacteristics, which can be described by fractal parameter. The more interesting discovery is thatthe surface fractal dimension values of the polymer particles vary periodically with thepolymerization time. We call this phenomenon fractal evolution, which can be divided into the'revolution' stage and the 'evolution' stage. And then we present polymerization fractal growingmodel (PFGM), and successfully describe and/or predict the whole evolving process of thepolyethylene particle morphology under the different slurry polymerization (includingpre-polymerization) conditions without H_2. 展开更多
关键词 polyethylene catalyst fractal evolution theory surface morphology polymerization fractal growing model
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Effects of IGF-Ⅱ on promoting proliferation and regulating nitric oxide synthase gene expression in mouse osteoblast-like cell 被引量:2
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作者 孙伟莲 陈莉丽 +1 位作者 严杰 余钟声 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2005年第7期699-704,共6页
Objective: To investigate the effects of insulin-like growth factor Ⅱ (IGF-Ⅱ) on promoting cell proliferation, regulating levels of cellular nitric oxide (NO) and mRNA transcriptions of inducible nitric oxide syntha... Objective: To investigate the effects of insulin-like growth factor Ⅱ (IGF-Ⅱ) on promoting cell proliferation, regulating levels of cellular nitric oxide (NO) and mRNA transcriptions of inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) in mouse osteoblast-like cells. Methods: Mouse osteoblastic cell line MC3T3-E1 was selected as the effective cell of IGF-Ⅱ. After the cells were treated with IGF-Ⅱ at different concentrations for different time duration,3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay was used to examine cell proliferation,and nitrate reductase method was applied to detect NO concentrations in cell culture supernatants and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was employed to determine transcription levels of cellular iNOS and eNOS mRNAs. Results: After the MC3T3-E 1 cells were treated with IGF-Ⅱ at concentration of 1 ng/ml for 72 h, 10 and 100 ng/ml for 24,48 and 72 h respectively, all the MTT values increased (P<0.05 or P<0.01) with obvious dosage-time dependent pattern. NO levels of the MC3T3-E1 cells treated with 100 ng/ml IGF-Ⅱ for 48 h, and with 1, 10 and 100 ng/ml IGF-Ⅱ for 72 h were remarkably lower than that of the normal control, respectively (P<0.05 or P<0.01). After the cells were treated with 100 ng/ml IGF-Ⅱ for 48 h cellular iNOS mRNA levels were significantly decreased (P<0.01). But the levels of eNOS mRNA in the cells treated with each of the used IGF-Ⅱ dosages for different time duration did not show any differences compared with the normal control (P>0.05).Conclusion: IGF-Ⅱ at different concentrations could promote proliferation of mouse MC3T3-E1 cell. This cell proliferation promotion was associated with the low NO levels maintained by IGF-Ⅱ. Higher concentration of IGF-Ⅱ could down-regulate iNOS gene expression at the level of transcription but not affect transcription of eNOS mRNA, which might be one of the mechanisms for IGF-Ⅱ maintenance of the low NO levels in MC3T3-E 1 cells. 展开更多
关键词 Insulin-like growth factor II OSTEOBLAST PROLIFERATION Nitric oxide synthase Nitric oxide Regulation
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The Arabidopsis PRCl-like ring-finger proteins are necessary for repression of embryonic traits during vegetative growth 被引量:19
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作者 Donghong Chen Anne Molitor +1 位作者 Chunlin Liu Wen-Hui Shen 《Cell Research》 SCIE CAS CSCD 2010年第12期1332-1344,共13页
Polycomb group genes play crucial roles in the maintenance of the transcriptionally silenced state of genes for proper cell differentiation in animals and plants. While components of the polycomb repressive complex2 ... Polycomb group genes play crucial roles in the maintenance of the transcriptionally silenced state of genes for proper cell differentiation in animals and plants. While components of the polycomb repressive complex2 (PRC2) are evolutionarily conserved and their functions are extensively studied in plants, PRCI differs considerably between animals and plants, and its functions in plants are as yet not well described. Previous studies have identified the Arabidopsis AtRINGla and AtRINGlb as homologues of the animal PRC1 subunit RING1. Here, we show that the Atringla Atringlb double mutant exhibits derepression of embryonic traits during vegetative growth. Accordingly, several key regulatory genes involved in embryogenesis and stem cell activity are ectopically expressed in the mutant. Furthermore, we show that the mutant phenotypes and increased expression of regulatory genes are enhanced by the PRC2 mutant c/f. Finally, we show that three homologues of the animal PRCl-subunit ring-finger protein BMI1, AtBMIIa, AtBMIlb and AtBMIlc, can bind with AtRINGla or AtRINGIb, and in addition, AtBMIlc can bind with LHP1. The Atbmila Atbmilb double mutant shows derepression of embryonic traits similar to that of the Atringla Atringlb double mutant. Interestingly, expression levels of AtBMIla, AtBMIlb and AtBMIlc are elevated in the Atringla Atringlb mutant and those of AtBMIlc, AtRINGla and AtRINGlb are elevated in the Atbmila Atbmilb mu- tant, suggesting a self-regulatory feedback mechanism. Taken together, our results illuminate crucial functions of the PRCl-like ring-finger components in stable repression of embryonic traits and regulatory genes for proper somatic growth. 展开更多
关键词 POLYCOMB PRC 1 RING 1 somatic embrvogenesis ARABIDOPSIS
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Parameter Optimization of CdZnTe Crystal Growth Simulated by Finite Element Method 被引量:1
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作者 MINJia-hua SANGWen-bing LIWan-wan LIUHong-tao YUFang WANGKun-shu CAOZe-chun 《Semiconductor Photonics and Technology》 CAS 2005年第1期20-27,共8页
During the crystal grown by VBM, the solid/liquid interface configurations greatly influence the quality of as-grown crystals. In this paper, finite element method (FEM) was used to simulate the growth process of CdZn... During the crystal grown by VBM, the solid/liquid interface configurations greatly influence the quality of as-grown crystals. In this paper, finite element method (FEM) was used to simulate the growth process of CdZnTe crystal. The effects of different crucible moving rates and temperature gradient of adiabatic zone on crystal growth rate and solid-liquid interface configuration were studied as well. Simulation results show that when crucible moves at the rate of about 1mm/h, which is nearly equal to crystal growth rate, nearly flat solid/liquid interface and little variation of axial temperature gradient near it can be attained, which are well consistent with the results of experiments. CdZnTe crystal with low dislocation density can be obtained by employing appropriate crucible moving rate during the crystal growth process. 展开更多
关键词 CDZNTE vertical bridgman method finite element method solid-liquidinterface configuration
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