Response preparation and control of movement sequences.

Two experiments investigated the response complexity effect using elbow extension/flexion movements. In Exp 1 with 30 undergraduates, reaction time (RT) for an extension movement was significantly less than RT for an extension/flexion movement. However, this difference in RT was not evident when participants were asked to pause at the reversal of the extension/flexion for approximately 260 msec. Exp 2 with 10 undergraduates manipulated the duration of the pause between these movements and also measured the electromyographical activity of the triceps and biceps muscles. When the pause was reduced to 75 msec, Ss were not able to program the flexion portion of the movement at the reversal, forcing them to preprogram this movement: hence, increasing their premotor RT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

取样方法和样品制备

本文旨在描述与取样方法和样品制备相关的“传统”概念和指导方法,给出了应用于钢铁以外的其他冶金分析领域的操作程序相关信息。然而,这些概念和程序绝大部分同铸造行业知识相关,与需要特别操作（如果需要相关操作）的其他可能领域并不相关。取样本身是个“无用”功,必须把这种行为当做“三角”工序中的一个角,而其他两个角是关注的基质和需要应用的技术。对样品制备适用性方面也进行了详细描述,应该考虑到采用的合金和要应用到的分析技术（方法）。鉴于实验样品是从“一块”样品中制取,应该注意到样品重新熔化的可能性和相关局限性。还要强调与制备缩分样品相关的一些特殊情况。与此同时,要注意到负责这些任务的操作者以及将“各种样品”送到实验室的客户（可称为第三方）的专业技能（或者说缺乏专业技能的情况）。最后,将指出“取样和样品制备”的现有标准以及与这些文件内容相关的“投诉”,因为有些内容的“强制性”不足,可能会导致“不好的”检测结果。
     

A comparison of canal preparation using the K-file and Lightspeed in resin blocks

Twenty-four resin blocks with simulated curved canals of approximately 38 degrees were divided into two groups of 12 each. One group was instrumented with stainless steel K-files and the other group with nickel-titanium Lightspeed Rotary instruments. The efficiency of canal preparation was evaluated at 1, 3, 5, and 7 mm from the apex using magnified images (x4) of the radiographed blocks. The results showed that K-files caused more widening at the apical end, with a higher incidence of transportation, zipping, and elbow formation. The Lightspeed instrument stayed centered in the canals maintaining the central axis, with minimal incidence of transportation, elbow formation, and zipping. Thus, the Lightspeed instrument may be considered more suitable for efficient preparation of curved canals than the K-type file.     

Identification and semi-quantitation of Ostertagia ostertagi eggs by enzymatic amplification of ITS-1 sequences

The forced oscillation technique (FOT) is a non-invasive method which may be suitable for assessing upper airway obstruction in obstructive sleep apnea/hypopnea syndrome (OSAS) patients. The aim of this study was to determine in vitro if FOT can provide an early detection index of total or partial upper airway occlusion. A respiratory system analog was developed which includes an upper airway analog that allows simulation of upper airway collapse (thus mimicking the situation in patients with OSAS). We simulated different degrees of upper airway obstructions ranging from 0 (unobstructed airways) to 1 (total occlusion). Furthermore, we imitated the collapsible upper airway wall by means of elastic membranes with ten different wall compliances ranging from 3.3 x 10(-4) to 1 1/mbar. For the two stiffest rubber membranes (Cwall = 0.01 and 3.3 x 10(-4) l/mbar) the absolute value of the impedance (?Z?) showed a marked increase for obstructions greater than 0.6. For the two membranes with the highest wall compliances (Cwall = 0.03 and 1 1/mbar) obstructions with an increase in ?Z? could not be detected before the obstruction reached 0.8. For degrees of obstruction less than 0.6 the phase angle of collapsible membranes with low compliance (stiff airway wall) were about 1.5pi which significantly differed from phase angles of 1.77pi measured in membranes with high compliance (elastic airway wall); p < 0.01. We hypothesized that stiffness of upper airway walls corresponds with their muscle tone, i.e., stiff airway walls are related with high muscle tone and vice versa. Thus, a decrease in upper airway muscle activity would cause an increase of upper airway wall elasticity that enables upper airway collapse. As a consequence the phase angle phi could be expected to change from values characterizing stiff membranes to values characterizing more elastic membranes which could be used as early indicator for obstructive respiratory events. We have frequently observed such changes in morphology of phi(t) data obtained from patients with OSAS.     

Electrolytic method of preparation of powder for ferrite manufacture

Summary The investigation demonstrated that an iron, nickel, and zinc hydroxide mixture of the required composition can be prepared electrolytically. The resultant system can readily be converted into an oxide mixture and used for ferrite manufacture. By using hydrochloric acid solutions as electrolytes, it is possible to deposit hydroxide mixtures of high purity and to eliminate washing, which is time consuming and requires a large quantity of distilled water.In contrast to the usual chemical method of hydroxide preparation, the electrochemical method makes it possible to produce, in a single, continuous technological process, a thoroughly blended oxide mixture of high purity and adequate homogeneity and to eliminate the time-consuming and laborious operation of mechanical mixing and comminution of starting oxide powders.     

Rapid preparation of tissue DNA from paraffin-embedded blocks and analysis by polymerase chain reaction

We have developed a new, easy, and more rapid method for DNA preparation, which avoids contamination. With this method, manual surgical blade scrapings from precisely targeted areas of paraffin block surfaces, without microtome cutting, were used to obtain tissues from 10 different neoplasms. Our results indicate the feasibility of DNA extraction from the scraped paraffin tissue for molecular genetic analysis. We applied this technique successfully to screen for the presence of human papillomavirus using the polymerase chain reaction (PCR) procedure in cases of endocervical, esophageal, and nasopharyngeal carcinomas, and to examine the expression of p53 gene from prostate and gastric adenocarcinomas. We conclude that this procedure is also suitable for purification of PCR products in analysis of the mutation or loss of allelic genes by Bstu I endonuclease digestion.     

A convenient method for the preparation of hapten phosphoramidites

Total midsagittal area and seven subdivisions of the corpus callosum were measured on magnetic resonance images of 114 healthy boys and girls, aged 4 to 18. Striking variability of size was noted for all measures. Total midsagittal corpus callosum area increased in a robust and linear fashion from ages 4 to 18 (slope = 13.1 mm2/year, P = 0.0001 and slope = 11.1 mm2/year, P = 0.0001 for females and males, respectively). Posterior and mid regions demonstrated greater age-related changes than anterior regions with the rostrum and genu (anterior regions) having reached adult sizes in the youngest of our subjects. There were no significant effects of sex for any measures. These findings support anatomical studies indicating ongoing myelination of higher association areas throughout adolescence, but raise intriguing questions about anterior-posterior gradients of interhemispheric myelination.     

A pilot-plant method for the preparation of complex carbides

Conclusions A study was made of the conditions of preparation of the complex carbides Ta_0.4W_0.6C, V_0.4W_0.6C, Nb_0.4W_0.6C, and Ta_0.4Mo_0.6C on a pilot-plant scale. It was found that the optimum method for the preparation of these complex carbides consists in sintering, for 4 h, charges containing a simple carbide, tungsten (molybdenum), and carbon black in a resistance furnace with a graphite heating element at 2500° C for Ta_0.4W_0.6C, Nb_0.4W_0.6C and Ta_0.4Mo_0.6C and at 2200° C for V_0.4W_0.6C.Translated from Poroshkovaya Metallurgiya, No. 2 (146), pp. 92–95, February, 1975.     

A magnesium-thermic method for the preparation of metal borides

Powder Metallurgy and Metal Ceramics -     

A subtractive hybridisation method for the enrichment of moderately induced sequences

Moderately induced genes often escape detection in conventional subtraction hybridisation cloning. Here a modification of a phagemid subtraction protocol is described that overcomes this problem. The protocol uses low ratio hybridisation of driver to target sequences to allow enrichment of the sequences of interest, and back-hybridisation of the subtracted sequences with induced sequences to reduce the accumulation of false positive clones. The procedure takes advantage of the quantitative representation of cellular RNA populations in cDNA libraries, therefore, they may serve not only as renewable sources of driver and target sequences, but also as sources of population cRNAs used in northern blots and differential Southern blots.     

A method for the preparation and quality control of 68Ga radiopharmaceuticals

Gallium-68 (T 1/2 68 min) is a convenient label for radiopharmaceuticals designed for use with positron detection devices; the radionuclide is a generator produce obtained from its parent 68Ge (T 1/2 287 days). The labeling procedure itself is simple since gallium forms complexes without the use of reducing agents. However, 68Ga is present in the generator eluant as the gallium-EDTA chelate and must be separated from EDTA prior to its use as a label. A rapid and efficient method for achieving this separation and for preparing 68Ga-labeled compounds for human use has been developed. Paper chromatography is employed to determine the amount of each major gallium species present in preparations of two gallium complexes; 68Ga-adenosine triphosphate and 68Ga-citrate.     

Substrate inhibition of beta-lactamases, a method for predicting enzymatic stability of cephalosporins

Selected cephalosporins, including cefamandole, cephaloridine, cephaloglycin, and cefoxitin, were examined for their ability to inhibit the enzymatic activity of and act as substrates for beta-lactamases produced by Enterobacter cloacae and Staphylococcus aureus. Enzyme inhibition was determined by Michaelis-Menten kinetic measurements and by a spot plate assay using a chromogenic substrate (Glaxo compound 87/312). These two methods provide comparable estimates of kinetic parameters. Inhibition of beta-lactamase, as measured by these two methods, was generally found to correlate with resistance to hydrolysis and is proposed as a preliminary method of assessing susceptibility of cephalosporins to beta-lactamase hydrolysis. Four 7-alphaOCH(3), 7-alphaH cephalosporin analogue pairs were also examined. The presence of the 7-alphaOCH(3) substituent invariably resulted in reduced susceptibility to enzymatic hydrolysis, regardless of the other C7 substituent. The 7-alphaOCH(3) compounds were also better inhibitors than were their 7-alphaH analogues, with the exception that 7-alphaOCH(3) compounds having C7 adipic acid substituents were less inhibitory to the S. aureus enzyme than were the corresponding 7-alphaH analogues. Response of these two enzymes to 7-alphaOCH(3) and 7-alphaH cephalosporins suggests that beta-lactamase hydrolysis of these compounds involves attack at the alpha side of the betalactam ring.     

高收得率黄金粉末的制备

为了黄金生产后续深加工工艺等方面的需要,目前我国有关黄金制粉技术的研发工作进展迅速。文中通过在国内某大型黄金企业成功实现高收得率黄金粉末的生产实践,就黄金这一贵重金属的制粉工艺特殊性及相关技术问题进行了较深入的分析和探讨,并指出低成本和高收得率是有效生产黄金粉末的关键。