高次时滞方程的周期正解

本文讨论方程Ｎ（ｔ）＝Ｎ９ｔ）（ａ（ｔ）－ｂ９Ｔ）Ｎ（ｔ－τ（ｔ））－ｃ（ｔ）Ｎ（ｔ－τｔ）））的周期正解的存在性,所获结果包含并改进了已知的结论。     

方程N′(t)=r(t)N(t)(1-bN(t-τ)-cN~2(t-τ))正平衡点的全局吸引性

本文给出保证平方Ｌｏｇｉｓｔｉｃ方程Ｎ′（ｔ）＝ｒ（ｔ）Ｎ（ｔ）（ｌ-ｂＮ（ｔ-τ）－ｃＮ２（ｔ-τ））的每一正解Ｎ（ｔ）趋于正平衡点Ｎ*的一组充分条件．改进了 Ｇａｐａｌｓａｍｙ,Ｌａｄａｓ和罗交晚等人的结果．     

一类Nicholson's blowflies模型的全局吸引性和振动性

本文研究了带有多个滞后变量的Ｎｉｃｈｏｌｓｏｎ’ｓ ｂｌｏｗｆｌｉｅｓ动态模型Ｎ（ｔ）＝－δＮ（ｔ）＋ΣＰｉＮ（ｔ-τｉ）ｅ-ａｉＮ（ｔ-τｉ）的全局吸引性和振动性,获得了该方程的正平衡解为全局稳定的充分条件以及其所有正解关于该平衡解振动的充分条件．     

慈溪麦冬甙A和B的结构

从浙江慈溪产中药麦冬（Ｏｐｈｉｏｐｏｇｏｎ ｊａｐｏｎｉｃｕｍ）中分离得到２个新的Ｃ２７甾体甙－－慈溪麦冬甙Ａ（２）和Ｂ（３）以及已知甙ｏｐｈｉｏｇｅｎｉｎ３－氧－α－Ｌ－鼠李糖吡喃基（１→２）「β－Ｄ－木糖吡喃基（１→３）」－β－Ｄ－葡萄糖吡喃甙（２）和ｏｐｈｉｏｇｅｎｉｎ ３－氧－α－Ｌ－鼠李糖吡喃基（１→２）「β－Ｄ－木糖吡喃基（１→３）」「β－Ｄ－葡萄糖吡喃基（１→４）」－β－Ｄ－葡萄糖吡     

在共培养体系中单克隆抗体AH6对小鼠胚泡着床的影响

以单克隆抗体ＡＨ６「特异结合Ｌｅ＾Ｙ寡糖,Ｆｕｃａ１－２Ｇａｌβ１－４（Ｆ痉－３）ＧｌｃＮＡｃ－」以及其它３种与Ｌｅ＾Ｙ寡糖结构近似的寡糖特异结构的单克隆抗体ａＬｅ＾ａ、ａＬｅ＾ｂ和ＦＥ－Ａ５为工具,采用小鼠体外着床模型。研究细胞表面Ｌｅ＾Ｙ寡糖抗原与着床的关系及其在着床过程中具体作用环节。     

云南永善产蜘蛛抱蛋的甾体成分

从云南省永善县产的百合科植物蜘蛛抱蛋（Ａｓｐｉｄｉｓｔｒａ ｅｌａｔｉｏｒ）根状茎中分离得到８个甾体化合物。其中６个为已知的甾体化合物,分别鉴定为（２５Ｓ）－３β－ｈｙｄｒｏｘｙ－ｓｐｉｒｏｓｔ－５－ｅｎｅ ３－Ｏ－β－Ｄ－ｇｌｕｃｏｐｙｒａｎｏｓｙｌ（１→）「β－Ｄ－ｘｙｌｏｐｙｒａｎｏｓｙｌ（１→３）」－β－Ｄ－ｇｌｕｃｏｐｙｒａｎｏｓｙｌ（１→４）－β－Ｄ－ｇａｌａｃｔｏｐｙｒａｎｏｓｉｄｅ     

狭基线纹香茶菜中一个新的木脂类素化合物

从狭基线纹香茶菜（Ｉｓｏｄｏｎ ｌｏｐｈａｎｔｈｏｉｄｅｓ ｖａｒ．ｇｅｒａｒｄｉａｎｕｓ「Ｂｅｎｔｈａｍ」Ｈ．Ｈａｒａ）的乙酸乙酯部分分离得到两个木脂类素化合物,经１Ｄ、２Ｄ－ＮＭＲ技术鉴定,分别为１－ａｃｅｔｏｘｙｌ－２ｅ,６ｅ－ｄｉｐｉｐｅｒｏｎｙｌ－３,７－ｄｉｏｘａｂｉｃｙｃｌｏ－「３,３,０」－ｏｃｔａｎｅ（１）和１－ａｃｅｔｏｘｙｌ－２ｅ－ｐｉｐｅｒｏｎｙｌ－６ｅ－「６－ｍｅｔｈｏｘ     

滇黄芩中五个新的黄酮类配糖体

从滇黄芩（Ｓｃｕｔｅｌｌａｒｉａ ａｍｏｅｎａ）根中分离到５个新的黄酮类配糖体。命名为滇黄芩甙甲－戊（ａｍｏｅｎｉｎｓＡ－Ｅ）。经光谱分析,化学结构分别证明为：２’,４’,６’－三羟基二氢查耳酮４’－「Ｏ－β－Ｄ－半乳吡喃糖基（１→２）」－Ｏ－β－Ｄ－葡萄吡喃糖甙,５,７,２’－三羟基－６－甲氧基二氢黄酮７－Ｏ－β－Ｄ－葡萄吡喃糖醛酸甙,（顺式）－５,７,２’－三羟基二氢黄酮醇３－Ｏ－β－Ｄ－葡萄     

闭鞘姜根中的甾体皂甙

从闭鞘姜「Ｃｏｓｔｕｓ ｓｐｅｃｉｏｓｕｓ（Ｋｏｅｎｉｇ）Ｓｍｉｔｈ」根茎中分离出五个化合物。经波谱解析和化学降解,证明其化学结构分别为胡萝卜甙（Ａ）：薯芋皂甙元３－Ｏ－ａ－Ｌ鼠李吡喃糖基（１－２）－β－Ｄ－葡萄吡喃糖甙（Ｂ）;薯芋皂甙元３－Ｏ－ａ－Ｌ－鼠李吡喃糖基（１－２）「ａ－Ｌ－鼠李吡喃糖基（１－４）」β－Ｄ葡萄吡喃糖甙（Ｃ）;薯芋皂甙元－３－Ｏ－ａ－Ｌ－鼠李吡喃糖基（１－２）「β－Ｄ－葡萄     

圆果雪胆中的皂甙成分

从圆果雪胆（Ｈｅｍｓｌｅｙａ ａｍａｂｉｌｉｓ）的块茎中分离到１０个化合物,其中３个雪胆皂甙是首次从该种植物中得到,它们的结构通过光谱和化学的方法鉴定为齐墩果酸－３－Ｏ－α－吡喃阿拉伯糖（１→３）－β－葡萄糖醛酸甙,２８－Ｏ－β－Ｄ－吡喃葡萄糖齐墩果酸３－Ｏ－α－吡喃阿拉伯糖（１→３）－β－Ｄ－葡萄糖醛酸,２８－Ｏ－β－Ｄ－吡喃葡萄糖齐墩果酸３－Ｏ－「β－Ｄ－吡喃葡萄糖（１→２）」－「α－吡喃阿     

关于一类时滞人口模型的全局吸引性

给出了保证时滞人口模型N'(t)=r(t)N(t) t≤0的每一正解N(t)趋于正平衡点 N*=1(t→∞)的一族充分条件．改进了Joseph和Yu的相关结果．     

Influence of Elevated CO2 Concentration and Nitrogen Source on Photosynthetic Traits in the Invasive Species Eupatorium adenophorum (Asteraceae)

Increases in the concentration of atmospheric CO2 and plant invasion are two important problems that face humans worldwide. In some plants, exposure to a short term elevated concentration of CO2 (SE［CO2］) promotes photosynthesis, but the promotion of elevated ［CO2］ (E ［CO2］) to photosynthesis might disappear after long term treatment (so called “CO2 acclimation”); this might result from the associated inhibition of nitrate assimilation. The present study investigated the physiological effects of short term (8 days) and long term (40 days) exposure to E［CO2］ when these were combined with different forms of inorganic N (full N; nitrate (NO3-) N) in the invasive species Eupatorium adenophorum. Exposure to E［CO2］ increased the biomass of Eadenophorum, regardless of the duration of exposure to E［CO2］ and the type of inorganic N that was supplied. E［CO2］ could promote the photosynthesis of Eadenophorum seedlings fertilised with non depleted Hoagland solutions (full N). For plants fertilised with NH4+ depleted Hoagland solution (NO3- N), LE［CO2］ treatment promoted the photosynthesis of Eadenop horum, but the promotion of photosynthesis by E［CO2］ disappeared under SE［CO2］ conditions. Photosynthetic pigments contents were determined to estimate potential changes in the photosynthetic capacity of Eadenophorum. For plants fertilised with non depleted Hoagland solution, there were no significant differences in chlorophyll among the three ［CO2］ treatments, but the treatment of SE［CO2］ increased the levels of chlorophyll in leaves. The apparent promotion of biomass accumulation and photosynthesis at LE［CO2］ without a decrease in chlorophyll indicates that Eadenophorum might not acclimate to long term exposure to E［CO2］. NH4+ depletion did not affect the capacity of LE［CO2］ to promote the photosynthesis of Eadenophorum. Thus, considering some plants fertilised with NO3- acclimating to LE［CO2］, Eadenophorum might be more competitive in areas where the soils are relatively poor in NH4+ as levels of atmospheric CO2 continue to rise.     

正颤蚓的生长发育及繁殖生物学的研究

在实验室饲养的条件下,研究了正颤蚓在15℃、20℃、25℃水温的生长发育和繁殖过程。结果表明正颤蚓从其受精卵在蚓茧内发育,孵出生长到产卵,在15℃水温需100—123d,在20℃水温需70—90d,在25℃水温需48—64d。蚓自蚓茧内孵出后的165d生长期内,其15℃、20℃、25℃水温的体重生长回归方程分别是W=6.87/［1+136.48     

通过筛选随机多肽文库研究ZO-1中PDZ1结构域的配体结合特点

选择ZO-1的PDZ1结构域作为研究对象,以酵母双杂交为筛选系统,筛选随机多肽文库和与其它PDZ结构域的配体进行相互作用,阐明ZO-1 PDZ1的配体结合特性.ZO-1 PDZ1识别配体C末端保守的氨基酸序列通式可以表示为：［S/T］［F/Y/W］［V/I/L/C］-COOH、［S/T］［K/R］V-COOH、V［F/Y/W］［L/C］-COOH、EYV-COOH.研究发现ZO-1 PDZ1的配体同时具有3种传统PDZ结构域配体的特点,不同的是其结合配体-1位对芳香族氨基酸具有强烈的偏好性.并且某些PDZ结构域配体的-1位和-3位对结构域与配体相互作用的特异性和亲和力有重要的作用.随后通过生物信息学的方法在Swiss-Prot数据库找到与此识别规律相符合的天然人类蛋白质.根据蛋白质的功能和细胞定位等性质选择10个配体用酵母双杂交验证相互作用.证实的相互作用配体有4个.本研究希望用这样的研究策略建立一种有效的研究蛋白质相互作用的方法,通过在全蛋白质组规模上对含有结合配体保守氨基酸序列的蛋白质的查询,理论上可以找到现有数据库中所有可能与目的结构域结合的潜在配体蛋白,特别是那些筛选cDNA文库不容易获得的低丰度配体.     

夏至草亲水性化学成分的研究

从夏至草正丁醇萃取物中分离得到6个化合物,运用光谱技术和化学方法鉴定了其中5个化合物的结构,其中1个为无机化合物KNO3（La1)另外4个为苯丙素甙,分别为purpureaside(La2),acteoside(La3),cistanoside B(La4),jionosideA(La5),均为首次从该属植物中获得。     

New Steroidal Glycosides from Ophiopogon japonicus

Two new C 27 steroidal glycosides, named ophiopojaponin A (1) and B (2), together with two known ones, were isolated from the tubers of the famous traditional Chinese herb Ophiopogon japonicus Ker-Gawl. The spectroscopic and chemical evidence revealed their structures to be pennogenin 3-O-［2′-O-acetyl-α-L-rhamnopyranosyl (1→2)］-β-D-xylopyranosyl (1→3)-β-D-glucopyranoside (1), 26-O-β-D-glucopyranosyl-(22ξ, 25R)-3β,14α,22ξ, 26-tetrahydroxyfurost-5-ene 3-O-α-L-rhamnopyranosyl (1→2)-β-D-glucopyranoside(2), diosgenin 3-O-［α-L-rhamnopyranosyl (1→2)］-β-D-xylopyrano-syl (1→3)-β-D-glucopyranoside (3) and ruscogenin 1-O-［α-L-rhamnopyranosyl (1→2)］-β-D-xylopyranosyl (1→3)-β-D-fucopyranoside (4).     

Affinity of transducin for photoactivated rhodopsin: dependence on nucleotide binding state

The interaction of the rod GTP binding protein, Transducin (G(t)), with bleached Rhodopsin (R(*)) was investigated by measuring radiolabeled guanine nucleotide binding to and release from soluble and/or membrane-bound G(t) by reconstituting G(t) containing bound GDP (G(t-)GDP) or the hydrolysis-resistant GTP analog guanylyl imidodiphosphate (G(t-)p[NH]ppG) with R* under physiological conditions. Release of GDP and p[NH]ppG from G(t) occurred to the same extent and with the same light sensitivity both in the presence and absence of added GTP. Significant amounts of G(t) without bound nucleotide (G(t-)) were generated. When ROS containing bleached rhodopsin (R(*)) were centrifuged in low ionic strength buffer, G(t-) remained associated with the membrane fraction, whereas G(t-)GDP remained in the soluble fraction. These results suggest that G(t-)GDP and G(t-)p[NH]ppG have similar affinities for R(*). The results also suggest that G(t-), rather than G(t-)GDP, is the moiety which exhibits tight, "light-induced" binding to rhodopsin.     

非线性非自治中立型时滞微分方程的周期解

本文研究非线性非自治中立型时滞微分方程N（t）=r（t）N（t）[a（t）-N（t-1）-c（t）N（t-1）],（E）得到方程（E）存在正周期解的充分条件．所得结果解决了Y·Kuang和A·Feldstein所提出的一个公开问题．     

Influence of Low Temperature on Spatial-temporal Changes of Ca2+ in Winter or Spring Wheat

Stained with Fluo-3/AM and investigated under the laser scanning confocal microscope (LSCM), the spatial-temporal changes of ［Ca2+］cyt(the free Ca2+ concentration in the cytoplasm) in the protoplasts of mesophyll cells of wheat (Triticum aestivum L.) cultivars with different cold-hardiness under resting and temperature decreasing conditions were compared. The results showed that under the resting condition, the fluorescence intensities in the protoplasts of both cold-sensitive and cold-resistant wheat manifested no significant changes, implying that ［Ca2+］cyt could keep at a stable level under the resting condition although different wheat cultivars were different. However, different dynamics appeared with temperature decreasing from 15℃ to 2℃. In particular, for the cold-resistant wheat, ［Ca2+］cyt level at first increased, followed by drop to the resting level at 2℃, and then increased further when the temperature was below 2℃. On the contrary, the ［Ca2+］cyt level of the cold-sensitive spring wheat increased continuously to the maximal level within the whole range of temperature changes. Based on the above observations, it could be reasonably inferred that different dynamics of ［Ca2+］cyt determines decisively different cold acclimation abilities of plants. Furthermore, the results provide a new supporting evidence for the hypothesis that Ca2+ plays a key role as a primary physiological transducer upon chilling”.     

The New Flavonoids from Polygonum sphaerostachyum (Polygonaceae)

Two novel flavone glycosides, 3′-hydroxy-5,4′-dimethoxy-6,7-methylenedioxyflavone-3-O-［β-D-xylopyranosyl(1→6)］-β-D-glucopyranoside(1)and5,4′-dimethoxy-3′-isopropenylacetyl-6,7-methylenedioxyflavone-3-O-［β-D-xylopyranoxyl(1→6)］-β-D-glucopyranoside (2), were isolated from Polygonum sphaerostachyum Meisn., and their structures were deduced by spectral and chemical methods. This is the first report on the isolation of flavone glycosides from P. sphaerostachyum.