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Search Results: 1 - 10 of 216321 matches for " ZHANG Wang-Feng "
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EFFECTS OF GAP AND UNDERSTORY EVIRONMENTS ON THE REGENERATION OF QUERCUS ALIENA VAR. ACUTESERRATA AND FAGUS ENGLERIANA
林隙与林下环境对锐齿槲栎和米心水青冈种群更新的影响

CHEN Zhi-Gang,FAN Da-Yong,ZHANG Wang-feng,XIE Zong-Qiang,
陈志刚
,樊大勇,张旺锋,谢宗强

植物生态学报 , 2005,
Abstract: 锐齿槲栎(Quercus aliena var.acuteserrata)和米心水青冈(Fagus engleriana)是广泛分布在我国暖温带和亚热带山地中海拔地段的主要建群种,对水土保持和维持生态系统稳定具重要意义.该文通过在神农架地区的典型样地调查,分析了这2个种群在林隙和林下不同光环境中的更新状况和径级结构;利用便携式Licor-6400光合仪测量了2种苗木的光饱和及光诱导曲线,探讨了光对这2个树种更新的影响机理.实验结果表明,在所调查的林地中,锐齿槲栎和米心水青冈种群都有充足的幼苗库,锐齿槲栎幼苗以实生为主,米心水青冈幼苗以萌生为主;从幼苗到幼树的转化过程中,锐齿槲栎的成活率几乎为零,而米心水青冈的成活率约为6%~8%;在两者的混交林中,米心水青冈种群呈稳定的金字塔形年龄结构,而锐齿槲栎则是某一生长阶段的种群占据主导地位.光饱和曲线显示,对2年生同生群苗木,在林窗下,锐齿槲栎的最大净光合速率(4.61μmol·m-2·s-1)比米心水青冈的(4.16 μmol·m-2·s-1)要高;而在林冠下,米心水青冈的最大净光合速率(Pn=3.89μmol·m-2·s-1)比锐齿槲栎的最大净光合速率(Pn=3.68μmol·m-2·s-1)要高.无论在林窗下或林冠下,米心水青冈幼苗的光饱和点比锐齿槲栎的要低.两者混交林下的光诱导曲线显示,与米心水青冈幼苗相比,锐齿槲栎幼苗对光的反应速度较慢,最大净光合速率也较低,在林冠下表现出较弱的竞争力.资源分配试验证明,锐齿槲栎在幼苗阶段以地上部分生长为主,而米心水青冈倾向于把更多的干物质贮藏在根部,显示出不同的光利用策略.
ACCLIMATION OF CATHAYA ARGYROPHYLLA TO LIGHT ACROSS A GRADIENT OF CANOPY OPENNESS
沿林冠开度梯度的银杉幼树对光的适应性

FAN Da-Yong,ZHANG Wang-Feng,CHEN Zhi-Gang,XIE Zong-Qiang,
樊大勇
,张旺峰,陈志刚,谢宗强

植物生态学报 , 2005,
Abstract: 用气体交换技术测定了四川省金佛山生长在一个典型林隙(林隙面积约为100m2)不同位置的银杉(Cathaya argyrophylla)幼树叶片的部分光合生理生态指标,用改进的鱼眼镜头法测定了所测叶片的林冠开度(CO),并测定了这些银杉幼树个体的生长状况.研究了沿林冠开度梯度银杉幼树对光的适应性.银杉幼树在林隙边缘表现出较好的适应性,包括当年生树高生长速率(HG)、平均地茎生长速率(DG)和当年冠幅生长速率(CG).随林冠开度的增加,单位叶面积的最大净光合速率(Pnarea)、暗呼吸速率(Rdarea)和单位叶面积的叶片干物质重(比叶重,SLM)明显增加,且相关显著.随林冠开度的增加,单位叶面积(LA)和单位叶干物质重的暗呼吸速率(Rdmass)略有降低,而单位叶片干物质重的最大净光合速率(Pnmass)和单位叶片干物质重(LM)略有升高,但相关不显著.沿林冠开度的银杉幼树的形态可塑性要略低于生理生态可塑性,但差异不显著.
Research on the photoprotection and photosynthesis characteristics of young cotton leaves under field conditions
田间条件下棉花幼叶光合特性及光保护机制

LI Wei,ZHANG Ya-Li,HU Yuan-Yuan,YANG Mei-Sen,WU Jie,ZHANG Wang-Feng,
李维
,张亚黎,胡渊渊,杨美森,吴洁,张旺锋

植物生态学报 , 2012,
Abstract: Aims Differences of photosynthesis and chlorophyll fluorescence characteristics between flat young leaves (young leaves) and fully grown leaves (mature leaves) of cotton were compared to study the adaptation mechanisms of photoinhibition and photoprotection on young leaves under strong sunlight. Methods We measured gas-exchange and chlorophyll fluorescence of young and mature leaves of cotton under field conditions and obtained rapid light curves with a Dual-PAM100 using an internal program. Important findings There were significant differences between young and mature leaves in photosynthesis and fluorescence characteristics. Young leaves had lower chlorophyll content (Chl) and stomatal conductance (Gs), which accounted for lower net photosynthetic rate (Pn), which in turn resulted in lower actual photochemical efficiency (ΦPSII) and photochemical quenching (qP) in photosystem II (PSII). Below 1 800 μmol·m–2·s–1, the higher cyclic electron flow (CEF) that was useful for composing ATP is one of the reasons for higher photosynthetic capacity in mature leaves. Lower light saturation point (LSP) was more susceptible to photoinhibition in young leaves under the same light; however, the magnitude of diurnal variation of its maximum photochemical efficiency of PSII (Fv/Fm) was significantly less than that of mature leaves. We suggest that photoprotective mechanisms, including direct quenching of reactive oxygen species by abundant carotenoids, photorespiration (Pr), non-photochemical quenching (NPQ) and the cyclic electron flow around PSI (PSI-CEF), can effectively dissipate the excess energy in young leaves to avoid photoinhibition under high irradiance.
EFFECTS OF PLANTING DENSITY ON CANOPY PHOTOSYNTHESIS, CANOPY STRUCTURE AND YIELD FORMATION OF HIGH-YIELD COTTON IN XINJIANG, CHINA
种植密度对新疆高产棉花群体光合作用、冠层结构及产量形成的影响

ZHANG Wang-Feng,WANG Zhen_Lin YU Song_Lie LI Shao_Kun FANG Jiang,TONG Weng_Song,
张旺锋
,王振林,余松烈,李少昆,房建,童文崧

植物生态学报 , 2004,
Abstract: 在新疆气候生态条件下,研究了种植密度对棉花(Gossypium hirsutum)群体光合作用、冠层结构和产量形成的影响,探讨了新疆棉花高产的生理机理及进一步提高产量的途径。结果表明:群体光合速率在盛铃期以前随密度增加明显增强,盛铃期以后,低密度6万株·hm-2的群体光合速率仍为最低,高密度30万株·hm-2群体光合速率迅速下降,中密度18万株·hm-2则保持较高水平。叶面积指数的变化与群体光合速率的变化相似,其峰值出现在盛铃期。冠层结构各指标的变化表现为,随密度增加平均叶簇倾角变大,株型变紧凑,但密度过大,群体散射辐射与直射辐射透过系数小,冠层结构不良,造成生育后期群体光合速率较快下降。增加密度能增加单位面积总铃数,但密度过高削弱了棉株个体发育,生育后期群体光合速率下降早,造成单铃重降低。群体总光合物质累积与群体光合速率在各生育时期呈显著正相关,籽棉产量与群体光合速率仅在盛铃期和吐絮期呈显著正相关;生产上要实现棉花高产及超高产,应使棉花生育前期群体光合速率稳定上升,至盛铃期达到高峰值,吐絮期群体光合速率保持较高水平
Effects of planting densities on canopy apparent photosynthesis, canopy structure and yield of cotton drip-irrigated under the mulch in Xinjiang
种植密度对新疆膜下滴灌棉花群体光合速率、冠层结构及产量的影响

LUO Hong-Hai,ZHANG Wang-Feng,ZHAO Rui-Hai,HAN Chun-Li,SHI Min,
罗宏海
,张旺锋,赵瑞海,韩春丽,施 敏

中国生态农业学报 , 2006,
Abstract: The field experiments on the effects of 3 planting densities on the canopy apparent photosynthesis,canopy structure and yield of cotton drip-irrigated under the mulch were conducted in earlier harvest area of North Xinjiang.The results indicate that the optimum population density of the cotton is 240000 plantlets/hm2,under which the canopy structure,canopy apparent photosynthesis,leaf index,dry matter accumulation and distribution and lint yield of cotton are better than those under other densities.
Regulation effect of water storage in deeper soil layers on root physiological characteristics and leaf photosynthetic traits of cotton with drip irrigation under mulch.
膜下滴灌下土壤深层水分对棉花根系生理及叶片光合特性的调节效应

LUO Hong-hai,ZHANG Hong-zhi,DU Ming-wei,HUANG Jian-jun,ZHANG Ya-li,ZHANG Wang-feng,
罗宏海
,张宏芝,杜明伟,黄建军,张亚黎,张旺锋

应用生态学报 , 2009,
Abstract: 在新疆气候生态条件下,以土柱栽培棉花(新陆早13号)为试材,通过人工改变播种前60 cm以下土壤含水量,设计有深层水和无深层水处理,并采用膜下滴灌控制生育期间耕层土壤含水量[分别为田间相对持水量的70%(±5%)和55%(±5%)],探讨土壤深层水分对棉花根系生理及叶片光合特性的影响.结果表明:深层水增强了棉花根系SOD活性和根系活力,提高了植株对土壤深层水的利用率,提高了叶片水势、叶绿素含量、净光合速率和植株光合物质累积量,最终获得了较高的产量和水分利用效率.在有深层水条件下,棉花生育期间耕层水分为55%处理的中下层根系衰老慢、根系活力增强,在一定程度上弥补了生育期间水分亏缺对叶片光合功能的负面效应,但其产量仍显著低于70%处理,而水分利用效率与70%处理无明显差异.因此,在膜下滴灌棉花水分管理中,播种前应重视冬春储备灌,增加土壤深层的贮水量,并通过协调关键栽培技术、适度减少滴水量或延长滴水周期,充分挖掘膜下滴灌节水增产潜力.
EFFECTS OF WATER DEFICIT ON PHOTOCHEMICAL ACTIVITY AND EXCITA-TION ENERGY DISSIPATION OF PHOTOSYNTHETIC APPARATUS IN COTIONLEAVES DURING FLOWERING AND BOLL-SETTING STAGES
土壤水分亏缺对陆地棉花铃期叶片光化学活性和激发能耗散的影响

ZHANG Ya-Li,LUO Hong-Hai,ZHANG Wang-Feng,FAN Da-Yong,HE Za-Ju,BAI Hui-Dong,
张亚黎
,罗宏海,张旺锋,樊大勇,何在菊,白慧东

植物生态学报 , 2008,
Abstract: 为了探讨水分亏缺对叶片光合机构光化学量子效率和非辐射热耗散的影响,在新疆气候生态条件下,采用膜下滴灌技术精确地控制滴水量,实现不同程度的土壤水分亏缺,系统测定了不同水分条件下陆地棉(Gossypium hirsutum)叶片叶绿素荧光参数、叶片接受光量子通量密度(Photon flux density,PFD)、叶片温度(Leaf temperature,Tleaf)以及叶片水势和叶绿素含量的变化。研究表明:轻度水分亏缺(田间持水量的55%-60%)叶片接受的PFD与对照(田间持水量的70%~75%)无差异,Tleaf略高于对照;中度水分亏缺(田间持水量的40%~45%)在12∶00(北京时间,下同)以前叶片接受的PFD和对照无差异,随后显著低于对照,Tleaf在整个日变化中均高于对照。不同水分处理对黎明前叶片PSⅡ最大光化学效率(The maximum photochemical efficiency of PSⅡ,Fv/Fm)没有影响。轻度水分亏缺叶片的实际光化学效率(PSⅡ photochemical efficiency,ΦPSⅡ)、表观电子传递速率(Electron transport rate,ETR)和光化学猝灭系数(Photochemical quenching,qp)的日变化与对照基本一致,非光化学猝灭系数(Non-photochemical quenching,NPQ)在12∶00以前和14∶00以后显著低于对照,在12∶00~14∶00和对照无差异。中度水分亏缺叶片的ΦPSⅡ、ETR和qp在12∶00才显著降低,此后由于叶片出现暂时萎焉、下垂,所接受的PFD减弱,叶绿素荧光参数缓慢恢复,且高于对照;NPQ在12∶00以前显著高于对照,14∶00略高于对照,此后低于对照。水分亏缺导致中午叶片水势和叶绿素a、叶绿素b含量降低,但叶绿素a/b比值升高。因此,在田间条件下,陆地棉可通过叶片萎焉下垂运动和叶绿素含量的变化调节叶片对光能的捕获,以及通过光合电子传递、热耗散水平的变化来适应水分亏缺的逆境。在中度水分亏缺条件下,陆地棉叶片萎焉下垂运动的被动调节减少了过量激发能对光合机构的伤害,保证了光合机构的正常运转。
Total Flavonoids of Scutellaria barbata Inhibit Invasion of Hepatocarcinoma via MMP/TIMP in Vitro
Zhi-Jun Dai,Bao-Feng Wang,Wang-Feng Lu,Zhi-Dong Wang,Xiao-Bin Ma,Wei-Li Min,Hua-Feng Kang,Xi-Jing Wang,Wen-Ying Wu
Molecules , 2013, DOI: 10.3390/molecules18010934
Abstract: Metastasis is the major cause of cancer-related deaths. Targeting the process of metastasis has been proposed as a strategy to fight cancer. Scutellaria barbata D. Don ( S. barbata), a traditional Chinese medicine, is used for treatment of many diseases, including cancer. This study aimed to determine the anti-metastatic effect of total flavonoids of S. barbata (TF-SB) using the human hepatocarcinoma MHCC97H cell line with high metastatic potential. Our results show that TF-SB could significantly inhibit the proliferation and invasion of MHCC97H cells in a dose-dependent manner. MMP-2 and MMP-9 expression were obviously decreased after TF-SB treatment at both the mRNA and protein level. TIMP-1 and TIMP-2 expression were simultaneously increased. The present study indicates that TF-SB could reduce the metastatic capability of MHCC97H cell, probably through decrease of the MMP expression, and simultaneous increase of the TIMP expression.
Antitumor Effects of Rapamycin in Pancreatic Cancer Cells by Inducing Apoptosis and Autophagy
Zhi-Jun Dai,Jie Gao,Xiao-Bin Ma,Hua-Feng Kang,Bao-Feng Wang,Wang-Feng Lu,Shuai Lin,Xi-Jing Wang,Wen-Ying Wu
International Journal of Molecular Sciences , 2013, DOI: 10.3390/ijms14010273
Abstract: Rapamycin (Rapa), an inhibitor of mammalian target of Rapamycin (mTOR), is an immunosuppressive agent that has anti-proliferative effects on some tumors. This study aims to investigate the effects of Rapa suppressing proliferation of pancreatic carcinoma PC-2 cells in vitro and its molecular mechanism involved in antitumor activities. MTT assays showed that the inhibition of proliferation of PC-2 cells in vitro was in a time- and dose-dependent manner. By using transmission electron microscopy, apoptosis bodies and formation of abundant autophagic vacuoles were observed in PC-2 cells after Rapa treatment. Flow cytometry assays also showed Rapa had a positive effect on apoptosis. MDC staining showed that the fluorescent density was higher and the number of MDC-labeled particles in PC-2 cells was greater in the Rapa treatment group than in the control group. RT-PCR revealed that the expression levels of p53, Bax and Beclin 1 were up-regulated in a dose-dependent manner, indicating that Beclin 1 was involved in Rapa induced autophagy and Rapa induced apoptosis as well as p53 up-regulation in PC-2 cells. The results demonstrated that Rapa could effectively inhibit proliferation and induce apoptosis and autophagy in PC-2 cells.
Antitumor activity of the selective cyclooxygenase-2 inhibitor, celecoxib, on breast cancer in Vitro and in Vivo
Zhi-Jun Dai, Xiao-Bin Ma, Hua-Feng Kang, Jie Gao, Wei-Li Min, Hai-Tao Guan, Yan Diao, Wang-Feng Lu, Xi-Jing Wang
Cancer Cell International , 2012, DOI: 10.1186/1475-2867-12-53
Abstract: Human breast cancer MCF-7 and MDA-MB-231 cells were cultured with different concentration (10, 20, 40 μmol/L) of celecoxib after 0-96 hours in vitro. MTT assay was used to determine the growth inhibition of breast cancer cells in vitro. The expression of COX-2 on mRNA was measured by real-time quantitive PCR analysis. Flow cytometry was performed to analyze the cell cycle of MCF-7 cells. Levels of PGE2 were measured by ELISA method. The in vivo therapeutic effects of celecoxib were determined using rat breast cancer chemically induced by 7,12-dimethylben anthracene (DMBA).The inhibition of proliferation of both MCF-7 and MDA-MB-231 cells in vitro by celecoxib was observerd in time and dose dependent manner. Celecoxib effectively down-regulated the expression of COX-2. The cell cycle was arrested at G0/G1, and rate of cells in S phase was obviously decreased. Levels of PGE2 were inhibited by Celecoxib. The tumor incidence rate of the celecoxib group was lower than that of the control group. In addition, the tumor latency period of the celecoxib group was longer than that of the control group.Celecoxib inhibited the proliferation of breast cancer cell lines in vitro, and prevented the occurrence of rat breast cancer chemically induced by DMBA. Therefore, celecoxib exhibits an antitumor activity and seems to be effective in anti-tumor therapy.Cyclooxygenases(COX) exists in two isoforms, namely, COX-1 and COX-2. They are rate-limiting enzymes in the formation of prostaglandins from arachidonic acid. COX-1 is considered to be constitutively expressed, while COX-2 is highly inducible by various factors and is associated with tumorigenesis by enhancing angiogenesis [1,2], suppressing apoptosis [3], and promoting invasiveness as well as metastases [4].COX-2 promotes carcinogenesis, tumor proliferation, angiogenesis, prevention of apoptosis, and immunosuppression [5]. COX-2 over-expression has been associated with tumor behavior and with prognosis in several cancers [6]. The
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