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Diode-like characteristics of nanometer-scale semiconductor channels with a broken symmetry

We present a new type of nanometer-scale semiconductor nonlinear device, called self-switching device (SSD). The device was realized by simply etching insulating grooves into a semiconductor, between which a narrow channel with a broken symmetry was formed. Because of the asymmetry in the channel boundary, an applied voltage V not only changes the potential profile along the channel direction, but

In vitro availability of starch in heat-treated potatoes as related to genotype, weight and storage time

The objective of the study was to determine the influence of potato variety, weight and storage time after lifting on the glycaemic index (GI) and resistant starch (RS) content predicted from measurement of the rate and extent of in vitro starch hydrolysis, respectively. The potatoes were either boiled, or boiled and subjected to different heat-cycling conditions selected to promote retrogradation

Escape from UV threats in zooplankton: A cocktail of behavior and protective pigmentation

In order to avoid environmental threats, organisms may respond by altering behavior or phenotype. Using experiments performed in high-latitude Siberia and in temperate Sweden, we show for the first time that, among freshwater crustacean zooplankton, the defense against threats from ultraviolet radiation (UV) is a system where phenotypic plasticity and behavioral escape mechanisms function as compl

Focusing of hard synchrotron radiation by a refracting glassy carbon lens

The first experimental study of focusing synchrotron radiation by a parabolic planar glassy-carbon lens is presented. The lens consists of four biconcave single lenses with a curvature radius of 0.2 mm and a relief height comparable with the lens aperture (similar to1 mm). One lens gives rise to the formation of a linear focus with a length comparable with the height of a parabolic profile. The us

Differential expression of gastrin, cholecystokinin-A and cholecystokinin-B receptor mRNA in human pancreatic cancer cell lines

BACKGROUND: It has been assumed that gastrin stimulates the growth of pancreatic cancer in an autocrine way through co-expression of gastrin and the cholecystokinin-B receptor (CCK-BR). However, pancreatic cancer cell lines established directly from patients have revealed a great heterogeneity in cell proliferation when exposed to CCK, gastrin and their receptor antagonists. The aim of this study

Trends in Software and Control

New software technologies are important for the future of control (and vice versa) in an age of increasing complexity. This paper discusses what are the trends.

Transformations of the natural dimeric phthalide diligustilide

A series of intramolecular condensation products were obtained by base-catalyzed treatment of the natural bioactive dimeric phthalide diligustilide (1) using different reaction conditions and the yields remarkably depend on these. The reaction conditions to obtain selectively the intramolecular condensation derivatives or the hydrolysis products of diligustilide (1) are described.

Determination of 5-hydroxy-N-methyl-2-pyrrolidone and 2-hydroxy-N-methylsuccinimide in human plasma and urine using liquid chromatography-electrospray tandem mass spectrometry

A method for simultaneous determination of 5-hydroxy-N-methyl-2-pyrrolidone (5-HNMP) and 2-hydroxy-N-methylsuccinimide (2-HMSI) was developed. These compounds are metabolites from N-methyl-2-pyrrolidone (NMP), a powerful and widely used organic solvent. 5-HNMP and 2-HMSI were purified from plasma and urine by solid-phase extraction using Isolute ENV+ columns, and analysed by liquid chromatography

Tissue reactions to polyethylene implants with different surface topography

This study investigates the importance of implant surface topography on soft tissue response. The tissue response in the rat abdominal wall to discs of low density polyethylene with smooth to coarse surfaces was evaluated after one, six or 12 weeks. Capsule thickness and immunohistochemical quantification of monocytes-macrophages were used as measures. The macrophage specific antibody ED1 was used

Acute centralization of blood flow in compromised human fetuses evoked by uterine contractions.

Background: During fetal hypoxia blood is redistributed to the brain ('brain-sparing'). Sequential changes of the cerebral and placental circulation in parallel in comparisons between basal conditions and acute hypoxic stress have not yet been thoroughly studied in human fetuses. Aim: To explore acute fetal middle cerebral artery (MCA) circulatory changes relative to umbilical artery (UA) blood fl

Unthermostated multichannel heat conduction calorimeter

Heat conduction calorimetry is a convenient method to detect cement-admixture incompatibility. However, such instruments tend to be used mainly in chemical laboratories. This paper presents the design of a simple unthermostated heat conduction calorimeter that can simultaneously monitor the heat production rate in 14 samples of cement paste or mortar. As it is not thermostated, its performance is

Definition av diastolisk hjärtsvikt

Hjärtsvikt är ett syndrom vars diagnostik baseras på kliniska symtom och/eller fynd i kombination med en objektiv undersökning av hjärtat. Diagnosen diastolisk hjärtsvikt har i praktiken visat sig svår att ställa i många fall. En orsak till detta är oklarheter i definitionen av tillståndet. Många patienter med diastolisk hjärtsvikt har även en nedsättning av den systoliska vänsterkammarfunktionen,

Lactam hydrolysis catalyzed by mononuclear metallo-beta-lactamases: A density functional study

Two central steps in the hydrolysis of lactam antibiotics catalyzed by mononuclear metallo--lactamases, formation of the tetrahedral intermediate and its breakdown by proton transfer, are studied for model systems using the density functional B3LYP method. Metallo--lactamases have two metal ion binding sites, one of which is occupied in the mononuclear species. In this work it is assumed that cata