Influence of diuretics on renal calcium excretion

Zusammenfassung Die renale Kalziumausscheidung wird bei einmaliger i.v. Zufuhr von Aminophyllin, Furosemid, Etacrynsäure, Azetazolamid und Chlorothiazid erhöht. Dies kann nicht nur durch die erhöhte Natriumausscheidung erklärt werden, sondern muss mit dem direkten tubulären Kalziumtransport im Zusammenhang stehen.     

Quantum states of neutrons in the Earth's gravitational field.

The discrete quantum properties of matter are manifest in a variety of phenomena. Any particle that is trapped in a sufficiently deep and wide potential well is settled in quantum bound states. For example, the existence of quantum states of electrons in an electromagnetic field is responsible for the structure of atoms, and quantum states of nucleons in a strong nuclear field give rise to the structure of atomic nuclei. In an analogous way, the gravitational field should lead to the formation of quantum states. But the gravitational force is extremely weak compared to the electromagnetic and nuclear force, so the observation of quantum states of matter in a gravitational field is extremely challenging. Because of their charge neutrality and long lifetime, neutrons are promising candidates with which to observe such an effect. Here we report experimental evidence for gravitational quantum bound states of neutrons. The particles are allowed to fall towards a horizontal mirror which, together with the Earth's gravitational field, provides the necessary confining potential well. Under such conditions, the falling neutrons do not move continuously along the vertical direction, but rather jump from one height to another, as predicted by quantum theory.     

广西石山地区大农业发展战略研究

农业基础薄弱和生态环境恶劣是制约石山地区农业发展的主要因素。据此,石山地区大农业发展战略是:治本抓基础,走生态农业和开发性农业的道路,发展资源转换型经济,达到不断提高粮食自给率、发展商品经济、尽快脱贫致富、改善生态环境的目的。以种养为主的庭院经济为突破口,以林业为重点。采取:1.依靠科学技术;2.建立健全社会化服务体系;3.建立以乡为地域单位,以户为生产和经营管理单位的农业生产商品基地,形成产业;4.稳定耕地和粮作面积,提高复种指数,主攻单产,提高总产;5.重视旱地农业,使旱地农业生产特别是玉米和大豆的生产有一个突破性发展;6.树立长期奋斗思想,进行持久的封山育林,把石山绿化起来;7.调整畜牧业结构,增加草食性牲畜和家禽的比重等战略措施。     

The use of primary cultures of adult rat hepatocytes to study induction of enzymes and DNA synthesis: Effect of nafenopin and electroporation

Summary Primary cultures of adult rat hepatocytes maintained in a well-differentiated state, in a chemically defined medium containing 2% DMSO, have been utilized to study the effect of non-mutagenic hepatocarcinogens such as the peroxisome proliferator nafenopin. The parameters chosen in this in vitro system were those that paralleled the major in vivo effects of nafenopin on the liver, mainly: the proliferation of the endoplasmic reticulum and induction of cytochrome P-452, the proliferation of the peroxisome compartment and the induction of cyanide-insensitive -oxidation of fatty acids and the stimulation of liver growth as measured by the DNA synthetic activity of the hepatocytes.In this review, we also describe the morphology of hepatocyte cultures prepared from previously electroporated hepatocytes and the potential for the use of electroporation to introduce growth related genes into hepatocyte cells to study the mechanisms of hepatocyte growth at the molecular level. In addition we describe the formation of endoplasmic reticulum whorls in these cultures as a consequence of nafenopin treatment. Whorl formation by hepatotrophic chemicals has been previously shown to occur in vivo; in this report, it is described for the first time in vitro.     

苯基环己基乙烷类液晶的合成及其性质

以４－烷基环已烷甲酸为原料,通过简单的合成路线合成了７个化合物。用红外光谱和核磁共振谱仪确定了这些化合物的结构。用偏光显微镜及ＤＳＣ仪确定了５个化合物是向列相液晶,并测定了它们的相交温度。讨论了化合物的分子结构对相变温度的影响。     

Strategy for rapid immobilization of prey by a fish-hunting marine snail

Some venomous animals capture prey with remarkable efficiency and speed. The purple cone, Conus purpurascens, uses two parallel physiological mechanisms requiring multiple neurotoxins to immobilize fish rapidly: neuromuscular block, and excitotoxic shock. The latter requires the newly characterized peptide kappa-conotoxin PVIIA, which inhibits the Shaker potassium channel 2-4, and beta-conotoxin PVIA5, which delays sodium-channel inactivation. Despite the extreme biochemical diversity in venoms, the number of effective strategic alternatives for prey capture are limited. How securely prey is initially tethered may strongly influence the venom strategy evolved by a predator.     

Mapping T-cell receptor-peptide contacts by variant peptide immunization of single-chain transgenics.

To test models of T-cell recognition, mice transgenic for T-cell receptor alpha or beta chain have been immunized with variant peptides that force changes in the resulting T-cell response. In particular, charge substitutions on the peptide often elicit reciprocal charges in the junctional (CDR3) sequences of T-cell receptor V alpha or V beta chains, indicating direct T-cell receptor-peptide contact, and allowing derivation of a topology for the T-cell receptor-MHC interaction. At one position on the peptide, variants transformed a homogeneous V beta response into a very heterogeneous one.     

In vitro conversion of steroid hormones in bovine ovarian follicles

Summary In bovine ovarian follicles an in vitro conversion of androstenedione and oestrone into oestradiol-17, and of oestradiol-17 into oestrone was observed. There was no in vitro conversion of pregnenolone, progesterone, dehydroepiandrosterone and testosterone.     

A population-specific HTR2B stop codon predisposes to severe impulsivity

Impulsivity, describing action without foresight, is an important feature of several psychiatric diseases, suicidality and violent behaviour. The complex origins of impulsivity hinder identification of the genes influencing it and the diseases with which it is associated. Here we perform exon-focused sequencing of impulsive individuals in a founder population, targeting fourteen genes belonging to the serotonin and dopamine domain. A stop codon in HTR2B was identified that is common (minor allele frequency >?1%) but exclusive to Finnish people. Expression of the gene in the human brain was assessed, as well as the molecular functionality of the stop codon, which was associated with psychiatric diseases marked by impulsivity in both population and family-based analyses. Knockout of Htr2b increased impulsive behaviours in mice, indicative of predictive validity. Our study shows the potential for identifying and tracing effects of rare alleles in complex behavioural phenotypes using founder populations, and indicates a role for HTR2B in impulsivity.