Mannan from the extracellular surface ofCandida albicans Berkhout

Zusammenfassung Aus der Oberfläche der Zellmembranen vonCandida albicans Berkhout wurde ein Mannan isoliert, das ausd-Mannose aufgebaut ist. Durch Methylierung und anschliessende saure Hydrolyse wurde bewiesen, dass es sich um ein verzweigtes Mannan mit -1–2- und -1–6-Bindungen handelt.     

An antinicotinic action of papaverine in the central nervous system

Zusammenfassung Die Wirkungen von Papaverin auf die kortikale Aktivität des Präparates «encéphalé isolé» der Katzen wurden untersucht. Papaverin rief homogene kortikale Synchronisation für einige Minuten hervor und verminderte kortikale Nikotin-Desynchronisation für einige Stunden.     

Uzarigenin and desglucouzarin fromAsclepias syriaca L

Zusammenfassung InAsclepias syriaca L. wurden neun Cardenolide nachgewiesen. Zwei Substanzen konnten in kristallisiertem Zustand isoliert und eine davon mit Uzarigenin identifiziert werden. Das zweite kristallisierte Produkt war das-d-Glucosid von Uzarigenin.     

Functional hydrogel structures for autonomous flow control inside microfluidic channels

Hydrogels have been developed to respond to a wide variety of stimuli, but their use in macroscopic systems has been hindered by slow response times (diffusion being the rate-limiting factor governing the swelling process). However, there are many natural examples of chemically driven actuation that rely on short diffusion paths to produce a rapid response. It is therefore expected that scaling down hydrogel objects to the micrometre scale should greatly improve response times. At these scales, stimuli-responsive hydrogels could enhance the capabilities of microfluidic systems by allowing self-regulated flow control. Here we report the fabrication of active hydrogel components inside microchannels via direct photopatterning of a liquid phase. Our approach greatly simplifies system construction and assembly as the functional components are fabricated in situ, and the stimuli-responsive hydrogel components perform both sensing and actuation functions. We demonstrate significantly improved response times (less than 10 seconds) in hydrogel valves capable of autonomous control of local flow.     

The radioprotective effect of solcoseryl

Zusammenfassung Solcoseryl^® ruft bei Mäusen 1 h vor Bestrahlung mit letalen Dosen von -Strahlen, i.p. oder p.o. appliziert, ein fast durchwegs 100%iges Überleben im Zeitraum von 30 Tagen hervor.     

Carnivorous Nepenthes pitcher plants are a rich food source for a diverse vertebrate community

Carnivorous pitcher plants capture insect prey to acquire essential nutrients while growing on extremely poor soils. A few individual species have evolved mutualistic relationships with small mammals that visit the traps to harvest nectar, and in return leave faecal droppings in the pitchers. Here we report that a diverse guild of nectar-harvesting vertebrates visits pitchers of two common lowland Nepenthes species without providing any obvious benefit for the plants. Over four consecutive field seasons, we observed four species of sunbirds and one species of tree shrew drinking nectar from pitcher plants. Foraging activity was highest in the morning and late afternoon. Van Hasselt’s, Brown-throated and olive-backed sunbirds were regular and highly abundant pitcher visitors in two different field sites. A crimson sunbird and a lesser tree shrew were each observed harvesting nectar on one occasion. The vertebrates harvested nectar from the pitcher rim (peristome) of N. rafflesiana and from the underside of the pitcher lid of N. gracilis. A comparison of the nectar production of these and three further sympatric species revealed exceptionally high quantities of nectar for N. rafflesiana. Other factors such as plant and pitcher abundance and the habitat preferences of the observed vertebrates are likely to also play a role in their choice to visit particular species. This is the first account of a case of obvious nectar robbing from Nepenthes pitchers by a guild of species that are too large to serve as prey, while the pitcher size and shape prevent faecal droppings from reaching the pitcher’s inside. This interaction provides an example of a possible starting point for the evolution of the elaborate mutualistic relationships observed in some species. Follow-up adaptations of pitcher shape could enable the plants to catch the droppings of their visitors and turn an exploitative relationship into a mutualism.     

在线滴定技术-连续流动滴定的应用

该文介绍了一种全新的在线滴定技术连续流动滴定,它通过一个由电子开关控制的与时间变化相连的三口双通螺旋管阀来控制和测定任何时间下（包括滴定终点时）样品与滴定剂的体积比,来代替传统滴定方法必须测定平衡点时滴定剂体积,实现了真正的在线滴定。通过优化系统设置的参数及仪器的部件,对实际样品进行分析,结果显示相对标准偏差低于1%,和传统技术相比无明显差异。仪器可以根据实验需要配置不同的检测系统,如：电位计、电导计及光度计等。同时,本仪器与自动滴定仪相比,消耗的样品和滴定剂是自动滴定仪的十分之一,滴定过程全自动、易于操作,分析速度更快,价格更低,易于广泛使用。