豆科黄结属模式及其相关种名的考证

长期以来,Ｔermopsis lanceolata R.Br.被误认为是黄华属的模式。根据有关文献考证和国际植物命名法规,作者为认Ｔ.;lanceoltata是一个不合法名,黄华属的合法模式应为Ｔhermopsis Lupinoides(L.)Link.分布于东北亚,花具互生花的黄华长期被误定为Ｔ。lupinoides(L.)Link,应更正为Ｔhermopsis fabacea(Pall)DC.。     

秦渭玫瑰精油研究

采用ISO9842和GB11538-89对在陕西渭南栽培的大马士革玫瑰“卡赞勒克”精油(工业化蒸馏法提取产品)进行了分析,结果表明,精油产品各项指标均符合ISO 9842和保加利亚БДС653标准要求。证明引种国际香型(纯甜型)玫瑰品种在陕西渭南栽培是成功的,所用精油提取工艺是合理的。     

Robotic Production of Cancer Cell Spheroids with an Aqueous Two-phase System for Drug Testing

Cancer cell spheroids present a relevant in vitro model of avascular tumors for anti-cancer drug testing applications. A detailed protocol for producing both mono-culture and co-culture spheroids in a high throughput 96-well plate format is described in this work. This approach utilizes an aqueous two-phase system to confine cells into a drop of the denser aqueous phase immersed within the second aqueous phase. The drop rests on the well surface and keeps cells in close proximity to form a single spheroid. This technology has been adapted to a robotic liquid handler to produce size-controlled spheroids and expedite the process of spheroid production for compound screening applications. Spheroids treated with a clinically-used drug show reduced cell viability with increase in the drug dose. The use of a standard micro-well plate for spheroid generation makes it straightforward to analyze viability of cancer cells of drug-treated spheroids with a micro-plate reader. This technology is straightforward to implement both robotically and with other liquid handling tools such as manual pipettes.     

Benthic insects in Swedish lake-outlet streams: patterns in species richness and assemblage structure

1. We studied how species richness of three hierarchical insect species groups, namely all benthic, lotic and filtering taxa, were related to a number of environmental variables in a data set from fifteen Swedish lake outlets. 2. In partial least-squares analyses, we found that size-related factors (stream width, discharge) and velocity-related factors (current velocity, substratum particle size) were positively associated, and productivity-related factors (chlorophyll a, seston energy, conductivity) negatively associated, with the species richness of the three groups. 3. The weak and negative relationship of richness with productivity largely negated theoretical predictions, whereas the species-environment results corroborated earlier findings from running water systems. 4. The most important factors associated with the species composition of the lake outlets studied included pH, lake area, discharge, channel width and detritus. 5. Of the filter feeders, most species of blackflies (Diptera: Simuliidae) showed a negative relationship with pH. 6. A nested subset analysis demonstrated that species-poor sites did not have a subset of species found at more species-rich sites in any of the three hierarchical groups.     

K+ channel KVLQT1 located in the basolateral membrane of distal colonic epithelium is not essential for activating Cl- secretion

The cellular mechanism for Cl^– and K⁺ secretion in the colonic epithelium requires K⁺ channels in the basolateral and apical membranes. Colonic mucosa from guinea pig and rat were fixed, sectioned, and then probed with antibodies to the K⁺ channel proteins K_VLQT1 (Kcnq1) and minK-related peptide 2 (MiRP2, Kcne3). Immunofluorescence labeling for Kcnq1 was most prominent in the lateral membrane of crypt cells in rat colon. The guinea pig distal colon had distinct lateral membrane immunoreactivity for Kcnq1 in crypt and surface cells. In addition, Kcne3, an auxiliary subunit for Kcnq1, was detected in the lateral membrane of crypt and surface cells in guinea pig distal colon. Transepithelial short-circuit current (I_sc) and transepithelial conductance (G_t) were measured for colonic mucosa during secretory activation by epinephrine (EPI), prostaglandin E₂ (PGE₂), and carbachol (CCh). HMR1556 (10 µM), an inhibitor of Kcnq1 channels (Gerlach U, Brendel J, Lang HJ, Paulus EF, Weidmann K, Brüggemann A, Busch A, Suessbrich H, Bleich M, and Greger R. J Med Chem 44: 3831–3837, 2001), partially (50%) inhibited Cl^– secretory I_sc and G_t activated by PGE₂ and CCh in rat colon with an IC₅₀ of 55 nM, but in guinea pig distal colon Cl^– secretory I_sc and G_t were unaltered. EPI-activated K⁺-secretory I_sc and G_t also were essentially unaltered by HMR1556 in both rat and guinea pig colon. Although immunofluorescence labeling with a Kcnq1 antibody supported the basolateral membrane presence in colonic epithelium of the guinea pig as well as the rat, the Kcnq1 K⁺ channel is not an essential component for producing Cl^– secretion. Other K⁺ channels present in the basolateral membrane presumably must also contribute directly to the K⁺ conductance necessary for K⁺ exit during activation of Cl^– secretion in the colonic mucosa. HMR1556; K⁺ secretion; epinephrine; prostaglandin E₂; cholinergic     

草地贪夜蛾对不同品种玉米的适应性比较研究

为了解不同玉米品种对草地贪夜蛾生长发育的影响,本文通过比较草地贪夜蛾Spodoptera frugiperda取食2种糯质型玉米(明玉1203和苏玉糯5号)与3种普通玉米(苏玉29、苏玉30和郑单958)后的发育历期、死亡率、蛹重、成虫畸形率、繁殖力与幼虫取食选择率等生物学参数,分析了草地贪夜蛾对不同品种玉米的适应性差...     

Effects of Low Root Temperature on Ion Uptake and Ion Translocation in Wheat

Roots of wheat seedlings (Triticum aestivum L. cv. Weibulls Starke) were cooled (+1°C) for 24 h while the shoots were kept at 25°C. The treatment induced an increased water deficit in the leaves. Fresh weight, dry weight, and the uptake and distribution of potassium and calcium were measured before and after cooling. Growth, measured both as fresh weight and dry weight increase, was reduced during the cold treatment. Afterwards (at 20°C), growth recovered to nearly pre-stress rates. Analysis of the potassium fluxes in and out of the roots by ⁸⁶Rb techniques showed that influx, and to a lesser extent efflux, were inhibited at low temperature. The result was a net potassium uptake rate of one-third that of unstressed plants. After the cooling period the potassium influx increased to the rate of control plants. The potassium efflux increased to one and one-half times the rate of unstressed wheat so that net uptake was negative. The increase in potassium efflux was explained by a higher permeability of the root cell membranes after cooling. The net uptake of calcium was reduced to one-third by root cooling. Contrary to potassium uptake, calcium uptake increased under post-stress conditions, partly due to a low efflux rate. During root cooling there was a redistribution of dry matter from the leaves down towards the lower part of the shoot. Afterwards the original distribution of dry matter was reestablished. The net flow of potassium and calcium followed a similar pattern as dry matter, suggesting a growth-regulated flow.