浅析160 kA预焙电解槽阳极效应系数控制

通过对贵铝二期160kA预焙电解槽阳极效碰系数的分析与讨论，发现AE系数与Al2O3浓度，计算机控制加工制度、原材料质量以及人工操作控制等因素有关。降低AE系数，有利于提高经济技术指标。提出了今后效应系数的控制发展方向。     

Reversible hydrogels from self-assembling artificial proteins

Recombinant DNA methods were used to create artificial proteins that undergo reversible gelation in response to changes in pH or temperature. The proteins consist of terminal leucine zipper domains flanking a central, flexible, water-soluble polyelectrolyte segment. Formation of coiled-coil aggregates of the terminal domains in near-neutral aqueous solutions triggers formation of a three-dimensional polymer network, with the polyelectrolyte segment retaining solvent and preventing precipitation of the chain. Dissociation of the coiled-coil aggregates through elevation of pH or temperature causes dissolution of the gel and a return to the viscous behavior that is characteristic of polymer solutions. The mild conditions under which gel formation can be controlled (near-neutral pH and near-ambient temperature) suggest that these materials have potential in bioengineering applications requiring encapsulation or controlled release of molecular and cellular species.     

三辊定径机轧辊机架安装调整设计分析

介绍了三辊内传动和外传动两种型式定径机轧辊机架的辊缝、齿侧间隙和轴承游隙的调整设计及装配方法,分析了影响安装调整的关键尺寸公差的控制,为三辊定径机轧辊机架的设计提供了参考.     

铸锭铣面机主轴轴承游隙的调整

介绍Ф212铸锭铣面机主轴轴承游隙的调整过程,阐述主轴轴承游隙是提高轴承旋转精度和承载能力的有效手段;强调保持良好的润滑,控制轴承温升,是保证轴承使用寿命的重要因素。     

Clearance of UVB-induced erythema in patients with non-melanoma skin cancer

We have examined the clearance of UVB-induced erythema in 10 non-melanoma skin cancer (NMSC) patients, comparing their responses to a control group. All participants were followed to resolution of erythema, as measured by a chromameter. The resultant response pattern was modelled in three phases, with comparison of the rates of decay in erythema carried out. Analysis of the rapid decay phase demonstrated a significantly slower rate of resolution of erythema in the NMSC group, compared with the controls. Further elucidation of the molecular and genetic mechanisms controlling this response may improve our understanding of UV-induced carcinogenesis.     

Cognitive difficulty of a peripherally presented visual task affects head movements during gaze displacement

Characterization of flow properties of an artificial ventricle may aid development of designs to minimize thrombosis. Techniques for determining two such flow properties, viz. ventricular clearance rate and ejection fraction, are compared and validated here for polyurethane and silicone rubber ventricles operated in a mock circulatory loop at various stroke volumes and pulse rates. Ventricular clearance rats were measured both by clinical radionuclide tracer techniques and by an optical tracer method. Ejection fractions were measured by radionuclide imaging and validated by direct measurements of flow rate and ventricular volume. Results from the two methods for ventricular clearance are in close agreement. The optical tracer method is superior in spatial resolution, convenience and economy, but the radionuclide tracer method for ejection fraction gives excellent agreement with the absolute measurements.     

Effect of hepatic insufficiency on pharmacokinetics and drug dosing

The liver plays a central role in the pharmacokinetics of many drugs. Liver dysfunction may not only reduce the plasma clearance of a number of drugs eliminated by biotransformation and/or biliary excretion, but it can also affect plasma protein binding which in turn could influence the processes of distribution and elimination. In addition, reduced liver blood flow in patients with chronic liver disease will decrease the systemic clearance of flow limited (high extraction) drugs and portal-systemic shunting may substantially reduce their presystemic elimination (first-pass effect) following oral administration. When selecting a drug and its dosage regimen for a patient with liver disease additional considerations such as altered pharmacodynamics and impaired renal excretion (hepatorenal syndrome) of drugs and metabolites should also be taken into account. Consequently, dosage reduction is necessary for many drugs administered to patients with chronic liver disease such as liver cirrhosis.     

动能自控密封器在烧结离心风机上的应用

济钢烧结厂烧结离心风机原采用迷宫加羊毛毡密封，因磨损出现轴承座漏油的问题。为此，安装使用了KH-6动能自控轴密封器，该密封器基于“以疏治漏”的理念，可使润滑介质在轴间径向摆振，伴随轴速形成S状轨迹软密封。应用表明，动能自控轴密封器彻底解决了风机润滑油的渗、漏问题，效果稳定，运行安全，仅节油一项年省费用达几十万元。     

Stimulus control of copulatory behavior in male Japanese quail

The copulatory behavior of sexually experienced male Japanese quail was tested using taxidermic models with varying proportions of natural and artificial features. Completely artificial models exerted little control over copulatory behavior, and whole natural body models reliably elicited copulatory behavior. In single model presentation tests, a model containing a natural head and neck with an artificial body was as effective in eliciting copulatory behavior as a whole body model, but a model containing a natural body with an artificial head and neck was largely ineffective. In choice tests, however, males clearly preferred a whole model over a natural head and neck model, and a natural body model over a completely artificial model. These data indicate male Japanese quail do attend to features of body plumage. Furthermore, test procedures can influence conclusions about effective controlling stimuli.     

Chimeric human-mouse IgG antibodies with shuffled constant region exons demonstrate that multiple domains contribute to in vivo half-life

Structural features that determine the differing rates of immunoglobulin catabolism are of great relevance to the engineering of immunologically active reagents. Sequences in the CH2 and CH3 region of IgG have been shown to regulate the rate of clearance through their interaction with FcRn. In an attempt to probe additional structural features that regulate antibody half-life, we have investigated two families of chimeric antibodies, composed of identical murine heavy and light antidansyl variable regions joined to human kappa light-chains and wild-type or shuffled human IgG heavy-chain constant regions. These antibodies were iodinated, and their clearance was studied in severe combined immunodeficient mice hosts by whole-body radioactivity measurements. Clearances of the wild-type and recombinant antibodies were biphasic. In a panel of immunoglobulins derived from IgG2 and IgG3, as successive domains were varied from gamma2 to gamma3, beta-phase half-life gradually decreased from 337.0 h to 70.6 h. Statistical analysis suggested that the composition of each of the three domains affected half-life, and no single region of the molecule by itself determined the rate of clearance. In the second panel of immunoglobulins derived from IgG1 and IgG4, the construct with the amino terminus portion of the molecule derived from IgG4, joined within the CH2 domain to the COOH terminus portion of IgG1, had a half-life paradoxically greater than either IgG1, or IgG4 (P < 0.012). All four IgG1/IgG4 constructs demonstrated presence of the concentration catabolism phenomenon, which is a unique hallmark of immunoglobulin catabolism. The contribution of all three constant region domains to immunoglobulin half-life may be due to distant conformational effects in addition to direct binding to protective receptors, and emphasizes the importance of distant sequences on the rate of immunoglobulin catabolism. Interesting possibilities regarding mechanisms controlling immunoglobulin metabolism are raised by the hybrid gamma4/gamma1 molecule with a half-life greater than either parental immunoglobulin. Understanding the relationships between the structure of these molecules and their clearance rate will further our ability to produce immunoglobulins with improved pharmacokinetic properties.     

Sublingual plicae (anterior processes) are not necessary for garter snake vomeronasal function.

The anterior processes of snakes may transfer odorants from the tongue to the vomeronasal (VN) organ. To test whether the anterior processes are required for a vomeronasally mediated behavior, the authors tested garter snakes (Thamnophis sirtalis) preoperatively and after cauterization of the anterior processes or control cauterization with artificial earthworms covered with earthworm wash (EWW) or distilled water. Snakes in both groups attacked EWW-covered artificial worms but not controls both pre- and postoperatively. In addition, snakes with anterior processes cauterization or control cauterization tongue flicked 3H-proline. Radioautographs of the VN organs of snakes with and without anterior processes were indistinguishable: Snakes in both groups had reduced silver grains over the VN sensory epithelium as had been reported previously with intact snakes. These findings indicate that the anterior processes are unnecessary both for a behavior known to require a functional VN system and for delivery of odorants to the VN organ. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Control and information in the intrapersonal sphere: An extension of cognitive evaluation theory.

Extended findings that support cognitive evaluation theory to intrapersonal processes by exploring the effects of informational vs controlling feedback, when self-selected and administered vs other-administered, and in conditions of task-involvement (intended to create an informational orientation in relation to the activity) vs ego-involvement (intended to create a controlling orientation in relation to the activity). 128 undergraduates working on a hidden figures task received either an ego- or task-involving induction and then a series of 3 puzzle problems for which half of the Ss received informational feedback and the other half controlling feedback. Half the Ss had the feedback self-administered, and half had it administered by the experimenter. After puzzle-solving, Ss were left alone with additional puzzles and magazines and were observed to see if they worked on the puzzles. Finally, Ss completed a questionnaire assessing their interest and attitudes toward the target activity. Results confirm that controlling feedback, whether self- or other administered, undermined intrinsic motivation relative to task-involvement. Results are discussed in terms of the application of cognitive evaluation theory to intrapersonal processes and self-control theories. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

ZKC-127矿用司控道岔在山东黄金集团焦家金矿寺庄分矿的应用

介绍了山东黄金焦家金矿寺庄矿区的生产运输任务的现状和道岔的使用情况,指出人工搬道器在使用中的弊端和使用ZKC-127矿用司控道岔装置的原因,阐述ZKC-127矿用司控道岔装置的系统结构、技术参数、工作原理,总结了该技术在焦家金矿寺庄分矿的安装使用状况。     

The prediction of human pharmacokinetic parameters from preclinical and in vitro metabolism data

We describe a comprehensive retrospective analysis in which the abilities of several methods by which human pharmacokinetic parameters are predicted from preclinical pharmacokinetic data and/or in vitro metabolism data were assessed. The prediction methods examined included both methods from the scientific literature as well as some described in this report for the first time. Four methods were examined for their ability to predict human volume of distribution. Three were highly predictive, yielding, on average, predictions that were within 60% to 90% of actual values. Twelve methods were assessed for their utility in predicting clearance. The most successful allometric scaling method yielded clearance predictions that were, on average, within 80% of actual values. The best methods in which in vitro metabolism data from human liver microsomes were scaled to in vivo clearance values yielded predicted clearance values that were, on average, within 70% to 80% of actual values. Human t1/2 was predicted by combining predictions of human volume of distribution and clearance. The best t1/2 prediction methods successfully assigned compounds to appropriate dosing regimen categories (e.g., once daily, twice daily and so forth) 70% to 80% of the time. In addition, correlations between human t1/2 and t1/2 values from preclinical species were also generally successful (72-87%) when used to predict human dosing regimens. In summary, this retrospective analysis has identified several approaches by which human pharmacokinetic data can be predicted from preclinical data. Such approaches should find utility in the drug discovery and development processes in the identification and selection of compounds that will possess appropriate pharmacokinetic characteristics in humans for progression to clinical trials.     

Comparative endocranial vascular changes due to craniosynostosis and artificial cranial deformation

The processes of craniosynostosis (premature fusion of one or more of the calvarial sutures) and artificial cranial deformation are similar since both can alter the shape of the craniofacial complex. Most research exploring these processes has focused on the ectocranium, although it is obvious that these processes also modify the endocranium. Endocranial changes due to either craniosynostosis or artificial cranial deformation have not been as thoroughly examined. Silicone rubber endocasts were made from 11 craniosynostotic archaeologically derived specimens from North and South America. For comparative purposes, endocasts were made from 22 normal and 17 occipitally deformed crania that were archaeologically derived from North and South America. With all samples, middle meningeal vessel patterns and venous sinus impressions were qualitatively and quantitatively analyzed. Depth, width, and convolution of the middle meningeal vessels were recorded, and the direction of vessel branches was noted. Both artificial cranial deformation and craniosynostosis altered the endocranial vasculature. Middle meningeal vessel and venous sinus impressions of the craniosynostotic group differed when compared to both the undeformed and artificially cranially deformed samples. Sinuses traversing under synostosed sutures became wider and deeper. In contrast, sinuses directly underneath the greatest artificial deformational stress were shallower, while there was compensatory enlargement of sinuses further away from the greatest deformational effects. Such compensatory enlargement also was shown by the high incidence of enlarged occipital/marginal sinuses in artificially deformed skulls. Increased intracranial pressure is hypothesized to be the cause of the venous sinus changes found in craniosynostotic individuals. Middle meningeal vessel patterns from craniosynostotic and artificially deformed specimens were similar in that their direction paralleled the direction of altered cranial growth. These findings demonstrate that the endocranial vasculature is developmentally plastic and responds to deformation in a predictable pattern.     

Is there still a role for functional radionuclide study of the liver?

Clinical applications of radionuclide methods for the study of liver hemodynamics and hepatocyte function are examined. In particular, as for hemodynamic studies, perfusion assessment with radiocolloids, 99mTc-IDA scintigraphy or 99mTc-labeled red blood cells, is underlined; they allow characterization of the different cellular component of space-occupying liver processes. The use of hepatic perfusion index (HPI) is reconsidered both as prognostic parameter in cirrhotic patients and as predictor of liver metastasis from colorectal cancer. The diagnostic role of recent procedures, as those based on endorectal radiopharmaceuticals in the evaluation of portosystemic shunts in cirrhosis, is analyzed. Studies of hepatocyte function of practical concern are essentially devoted to the "excretory function" and "asialoglycoprotein metabolism". In the first case, a major role is played by IDA halogenated derivatives and functional parameters drawn from them by mathematico-statistical evaluations of radiohepatogram (simple or applied to compartmental models). For metabolic studies, at present an artificial glycoprotein, 99mTc-galactosylneoglycoalbumin (99mTc-NGA) that binds with hepatocellular receptors is used. Information on the rate of blood plasma clearance and liver uptake, receptor density (altered in some pathologic conditions) and plasmic hepatic flow, is supplied.     

Preliminary experience with medical applications of rapid prototyping by selective laser sintering

Rapid prototyping techniques, originally developed for building components from computer aided designs in the motor industry, are now being applied in medicine to build models of human anatomy from high resolution multiplanar imaging data such a computed tomography (CT). The established technique of stereolithography and the more recent selective laser sintering (SLS), both build up an object layer by layer. Models have applications in surgical planning, for the design of customised implants and for training. Preliminary experience of using the SLS technique for medical applications is described, addressing questions regarding image processing, data transfer and manufacture. Pilot models, built from nylon, included two skills (a child with craniosynoslosis and an adult with hypertetorism) and a normal femur which was modelled for use in a bioengineering test of an artificial hip. The dimensions of the models were found to be in good agreement with the CT data from which they were built-for the child's skull the difference between the model and the CT data was less than 1.0 +/- 0.5 mm in each direction. Our experience showed that, with care, a combination of existing software packages may be used for data conversion. Ideally, image data of high spatial resolution should be used. The pilot models generated sufficient clinical interest for the technique to be pursued in the orthopaedic field.     

治理沙害保护生态环境

金厂峪金矿老尾矿坝植被治理,获得了成功,有效地保护了生态环境.为矿山尾砂治理,摸索出一条成功的经验.对企业来说,投资少,简便易行.对发展山区畜牧业生产有可行价值.     

工程机械履带用钢的研制

工程机械履带用钢,是机械工业大量使用的钢材,对钢的机械性能要求十分严格。履带用钢开发过程中通过制定严谨合理的生产工艺,优化电炉、精炼及连铸工艺,合理控制过程参数,对钢水的终点成分、连铸配水、铸坯拉速等进行严格控制,钢材的表面质量、低倍组织、非金属夹杂物、晶粒度、金相组织等冶金质量均满足技术条件要求,性能指标达到国内先进水平。