肝素钠的生产及其存在的问题和解决的方法(Ⅲ)--无蛋白品和精品的生产

本文从技术路线、原料控制和设备设施等方面对肝素钠无蛋白品和精品的生产进行了论述,并就如何提高品质收率和目前存在的一些问题进行探讨.     

Molecular phylogeny of Glyphochloa (Poaceae,Panicoideae), an endemic grass genus from the Western Ghats,India

The genus Glyphochloa (Poaceae: Panicoideae: Andropogoneae: Rottboellinae) is endemic to peninsular India and is distributed on lateritic plateaus of low and high altitude in and around Western Ghats and the Malabar Coast. The genus presumably originated and diversified in the Western Ghats. Species relationships in the genus Glyphochloa were deduced here based on molecular phylogenies inferred using nuclear ribosomal ITS sequences and plastid intergenic spacer regions (atpB-rbcL, trnT-trnL, trnL-trnF), and new observations were made of spikelet morphology, caryopsis morphology and meiotic chromosome counts. We observed two distinct clades of Glyphochloa s.l. One of these (‘group I’) includes Ophiuros bombaiensis, and is characterized by a single-awned lower glume and a base chromosome number of 6; it grows in low elevation coastal areas. The other clade (‘group II’) has a double-awned lower glume, a base chromosome number of 7, and is restricted to higher elevation lateritic plateaus; G. ratnagirica may belong to the group II clade, or may be a third distinct lineage in the genus. A sister-group relationship between group I and II taxa (with or without G. ratnagirica) is not well supported, although the genus is recovered as monophyletic in shortest trees inferred using ITS or concatenated plastid data. We present a key to species of Glyphochloa and make a new combination for O. bombaiensis.     

籼稻颖花分化与退化对不同播期温光的响应

试验以三系杂交籼稻‘五优308’和‘天优华占’以及常规籼稻‘黄华占’为材料,在大田条件下,设置10个播期,研究田间不同温光条件对籼稻生育期天数、颖花分化和退化数的影响.结果表明: 温度对3个籼稻品种生育期的影响比日照长度大,平均温度升高1 ℃,播种-穗分化始期天数平均减少1.5 d,而穗分化历期天数与光照和温度的关系均不密切.不同播期间每穗颖花数和颖花分化数存在显著差异.穗分化期间平均温度、最高温度和最低温度升高,有效积温增加,昼夜温差扩大,光辐射增强,有利于穗分化期干物质积累和颖花分化,各品种趋势一致.穗分化期间有效积温增加50 ℃,颖花分化数增加10.5朵,昼夜温差扩大1 ℃,颖花分化增加14.3朵,总光辐射量增加50 MJ·m^-2,颖花分化数增加17.1朵.颖花退化率与温度呈现二次项相关,极端高温或极端低温的自然条件不利于颖花形成,但低温天气对颖花退化的影响大于高温.温度低于临界温度,颖花退化率大幅增加,穗分化期临界积温为550～600 ℃,日平均温度为24.0～26.0 ℃,日最高温度为32.0～34.0 ℃,日最低温度为21.0～23.0 ℃.适宜高温、昼夜温差大、光照辐射强的自然条件利于颖花分化,并减少颖花退化.     

细菌苏氨酸脱水酶受L-异亮氨酸反馈抑制的关键在于其调控结构域

苏氨酸脱水酶是细菌L-异亮氨酸合成途径中的关键酶,酶活力受终产物L-异亮氨酸的反馈抑制。苏氨酸脱水酶包含催化结构域及调控结构域,其中调控结构域所起的作用有待进一步研究。本文在大肠杆菌中分别克隆表达了四种不同的苏氨酸脱水酶:来自谷氨酸棒杆菌的苏氨酸脱水酶CgIlvA及其不合调控结构域的突变体CgIlvA~M和来自大肠杆菌的苏氨酸脱水酶EcIlvA及其不合调控结构域的突变体EcIlvA~M。通过蛋白纯化和酶活分析发现,CgIlvA~M和EcIlvA~M的酶活力比CgIlvA和EcIlvA的酶活力有所降低,但它们不再受L-异亮氨酸的反馈抑制,说明L-异亮氨酸对苏氨酸脱水酶的反馈抑制是通过其调控结构域来实现的。     

Decoction of heat-clearing,detoxifying and blood stasis removing relieves acute soft tissue injury via modulating miR-26b-5p/COX2 axis to inhibit inflammation

Traditional Chinese medicine (TCM), such as Huanglian-Jie-Du-Tang, a heat-clearing and detoxifying decoction is beneficial for alleviation of inflammation-related diseases. The objective of the present study is to uncover the effect and mechanism of heat-clearing, detoxifying and blood stasis removing decoction (HDBD) on the treatment of acute soft tissue injury (STI) which is characterized with excessive inflammatory cascade at the onset. Male Sprague–Dawley (SD) rats with hammer beating served as the in vivo models of acute STI. Hematoxylin–Eosin (HE) staining was used for histopathology assessment. The levels of inflammatory factors, including prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), interleukin (IL)-1t and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA). Human dermal microvascular endothelium cell line HMEC-1 and rat vascular endothelium cell line RAOEC were used to explore the mechanism in vitro. Luciferase gene reporter assay was applied to determine the relationship between miR-26b-5p and Cyclo-oxygenase 2 (COX2). The results showed that HDBD intervention significantly reduced the temperature difference between the healthy side and affected side of rats with hammer beating, together with the decreased levels of COX2, PGE2, TNF-α, IL-6 and IL-1β, and the increased level of miR-26b-5p. In mechanism, miR-26b-5p targeted COX2 and decreased its expression, leading to significant decreases in the levels of PGE2, TNF-α and IL-6 in RAOEC and HMEC-1 cells. In addition, miR-26b-5p inhibition impaired the effects of HDBD on the suppression of PGE2, TNF-α, IL-6 and IL-1β in vitro. In conclusion, the present study revealed that HDBD relieved acute STI via modulating miR-26b-5p/COX2 axis to inhibit inflammation.     

Ethylene inhibitors promote male gametophyte survival in rice

Rice (Oryza sativa L. cv. Lalat) was grown in pots under open field conditions during the wet season of 1997. Attempts were made to manipulate the growth and development of the male gametophyte, located on the basal region of the panicle, by exogenous application of chemicals regulating formation/action of ethylene and compare grain setting in the spikelets bearing few grain. Application of ethylene action (AgNO₃) and synthesis inhibitor (Co(NO₃)₂; paclobutrazol and uniconazole) improved grain setting in the spikelets and the ethylene releasing substance 2-chloroethyle phosphonic acid (CEPA) depressed it compared to the control. The ethylene inhibitors promoted dry mass accumulation and concentrations of starch and reducing sugars in the anthers of the basal spikelets, while CEPA reduced the level of these carbohydrates significantly. The ethylene inhibitors helped in the survival of more numbers of pollen in these anthers, but CEPA depressed their number significantly. Promotion of growth of the basal anthers was accompanied by a concomitant reduction in the concentration of nonreducing sugars and enhanced activities of acid invertase and sucrose synthase enzymes. It is concluded that male gametophyte development of the basal spikelets of rice is susceptible to ethylene at the stage of pollen mitosis. The possibility of the hormone interfering in carbohydrate metabolism of the anther during this stage of development is discussed.     

The fate of phosphate under anoxic conditions in biological nutrient removal activated sludge systems

The nitrogen removal potential of phosphate accumulating organisms under anoxic conditions has been evaluated using a laboratory scale sequencing batch reactor fed with synthetic wastewater and operated in a sequence of anaerobic, anoxic and aerobic periods. The phosphate uptake rate under anoxic conditions was lower than that under aerobic conditions. However, in the presence of an external substrate such as glucose and acetate, the fate of phosphate was dependent on the substrate type; phosphate release occurred in the presence of nitrate as long as acetate was present and glucose did not cause any phosphate release. The nitrate uptake rate was also much lower with glucose than acetate. The results implied that poly-hydroxyalkanoates could be oxidized by nitrate and phosphate uptake during the anoxic phase should be introduced into process modeling. © Rapid Science Ltd. 1998     

Effects of water stress and high temperature on gas exchange and chlorophyll fluorescence in Triticum aestivum L.

Wheat plants grown in controlled growth chambers were exposed to drought stress (DS) and high temperature (HT) singly and in combination (DS+HT). The effects of these two stresses on net photosynthetic rate (P _N), stomatal conductance (g _s), intercellular CO₂ concentration (C _i), quantum efficiency of photosystem 2 (Φ_PS2), variable to maximum chlorophyll (Chl) fluorescence (F_v/F_m), photochemical (q_p) and non-photochemical (NPQ) Chl fluorescence, and yield were investigated. Grain yield was decreased by 21 % due to DS, while it was increased by 26 % due to HT. P _N, g _s, C _i, and Chl fluorescence were dramatically reduced to DS, HT, and their interaction, except NPQ which showed an increase due to HT.