厌氧胶：可靠且节约成本紧固件的锁紧和密封

当机械设备发生故障时,厌氧螺纹锁固剂便可发挥作用。正如赛车的特滑层有助于确保车辆在赛道的抓地力,螺纹锁固剂有助于保证紧固件螺纹的夹持力。根据厌氧技术,这些金属胶粘剂可以实现机械辅助措施无法实现的功能：它们可完全填满连接螺纹之间的微小间隙。使用螺纹锁固剂固定的螺栓可以提供比机械装置更好的夹紧力。专用螺母或垫圈的价格是液体螺纹锁固剂的5倍以上。采用液体螺纹锁固剂可降低库存成本。在选择螺纹锁固复合物时,有一些关键因素需要考虑：抗剪强度、固化速度、间隙填充能力和工作环境。     

Metabolism of monoterpene alcohol, linalool, by a soil pseudomonad

A microorganism of the genus Pseudomonas has been isolated from the soil by enrichment culture techniques with linalool(I) as the sole source of carbon and energy. The organism is also capable of utilizing limonene, citronellol, and geraniol as substrates but fails to grow on citral, critranellal, and 1,8-cineole. Fermentation of linalool by this bacterium in a mineral salt medium results in the formation of 10-hydroxylinalool(II), oleuropeic acid (IX), 2-vinyl-2-methyl-5-hydroxyisopropyl-tetraphydrofuran)linalool oxide, V), 2-vinyl-2-methyl-tetrahydrofuran-5-one(unsaturated lactone, VI), and few unidentified minor metabolities. Probable pathways for the biodegradation of linalool are presented.     

The chi psi subunits of DNA polymerase III holoenzyme bind to single-stranded DNA-binding protein (SSB) and facilitate replication of an SSB-coated template

A complex of the chi and psi proteins is required to confer resistance to high levels of glutamate on the DNA polymerase III holoenzyme-catalyzed reaction (Olson, M., Dallmann, H. G., and McHenry, C. (1995) J. Biol. Chem. 270, 29570-29577). We demonstrate that this salt resistance also requires templates to be coated with the Escherichia coli single-stranded DNA-binding protein (SSB). We show that this is the result of a direct chipsi-SSB interaction that is strengthened approximately 1000-fold when SSB is bound to DNA. On model oligonucleotide templates, DNA polymerase III core is inhibited by SSB. We show that the minimal polymerase assembly that will synthesize DNA on SSB-coated templates is polymerase III-tau-psi chi. gamma, the alternative product of the dnaX gene, will not replace tau in this reaction, indicating that tau's unique ability to bind to DNA polymerase III holding chipsi in the same complex is essential. All of our findings are consistent with chipsi strengthening DNA polymerase III holoenzyme interactions with the SSB-coated lagging strand at the replication fork, facilitating complex assembly and elongation.     

Attentional effects of single dose triazolam

1. While the effects of benzodiazepines on human memory have been extensively studied little is known about the effects of these agents on attentional processes. The authors studied the effects of a single dose of triazolam on selective visual-spatial attention using a double blind, placebo controlled design. 2. In each of 2 sessions 12 normal volunteers ingested either 0.25 mg of triazolam or placebo. Attentional performance was evaluated using two versions of the covert orienting paradigm which measured automatic (exogenous) and controlled (endogenous) aspects of attentional orienting, respectively. 3. Triazolam selectively modified performance on automatic orienting to exogenous cues. Specifically, triazolam increased the facilitation of target detection seen at shorter (150 msec) SOA's. This may indicate an increase in facilitation and a reduction in inhibition or a slowing of the time course of the biphasic attentional effect normally resulting from exogenous cuing. 4. These results indicate the importance of using experimental paradigms which effectively dissociate endogenous and exogenous mechanisms of spatial orienting in studies evaluating the effects of pharmacological agents on visual-spatial attention.     

Functional longevity of intraperioneal drains: an experimental evaluation

Various types of drains were inserted into the peritoneal cavity of twenty-eight dogs. After one to seven days, all drains failed to show the presence of 200 cc of colored fluid injected intraperitoneally. On autopsy, all tubes were surrounded and occluded by omentum.     

The pharmacokinetics of ephedrine after oral dosage in asthmatics receiving acute and chronic treatment

1 Ephedrine plasma levels have been measured in ten asthmatic patients given a singel dose of ephedrine hydrochloride (22 mg) along and in combination with theophylline and a barbiturate. 2 Pharmacokinetic assessment of the data indicated no significant intra-subject changes in kinetic parameters before or after chronic treatment with ephedrine HCl (11 mg three times a day) alone or in combination. 3 Tolerance to these therapeutic doses, if it occurs, is therefore not disposition-related but rather to pharmacodynamic changes.     

Vitamin C elevates red blood cell glutathione in healthy adults

Pre-transplant nephrectomy was done in a 25-year-old man for calculous pyelonephritis using a retroperitoneal laparoscopic approach with a newly devised ligature applicator-dissector- kidney retractor.     

Coarsening of hafnium carbide particles in tungsten

The coarsening behaviour of finely dispersed HfC particles in a W-HfC alloy was investigated by monitoring the growth rate of the particles. An activation energy of 480 kJ mol^–1 was obtained for the process. Diffusion experiments of hafnium in tungsten were conducted at temperatures between 1773 and 2573 K using a secondary ion mass spectroscopy technique to determine the diffusion contribution to the coarsening process. The diffusion process at high temperature is controlled by lattice diffusion with an activation energy of 335 kJ mol^–1 whereas that at low temperature is governed by grain-boundary diffusion with an activation energy of 170 kJ mol^–1. It appears that the coarsening process is controlled by two energy barriers: one dictated by the diffusivity of hafnium and the other by the solubility limit as a function of temperature. The strain energy required to dissociate the carbide particles into individual species was also considered. The effects of the coarsening of HfC particles in a dispersion-strengthened W-0.4 mol% HfC alloy on recrystallization and creep deformation were illustrated using a concerted experimental modelling analysis. Results show that the strengthening effect of the HfC particles is significantly reduced at temperatures above 1800 K, due to particle coarsening.