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41.
S Hatano DM Keane RE Boggs MA El-Naggar MS Sadove 《Canadian Metallurgical Quarterly》1976,23(6):648-656
Two hundred open-heart cases were anaesthetized with a diazepam-ketamine combination. The results were excellent. A "Micro-Mini" drip technique insured low, even, but adequate dose levels of ketamine and less drug was used. Induction and maintenance are simple and smooth. Effects on the cardiovascular system and respiratory system are minimal. The margin of safety is wide and 100% oxygen can be used whenever needed. 相似文献
42.
J. R. White B. de Poumeyrol J. M. Hale R. Stephenson 《Journal of Materials Science》2004,39(9):3105-3114
A piezoelectric ceramic-polymer composite has been developed for use as a novel thick film strain sensor for vibration monitoring of structures. The material is in the form of a paint that can be applied to a wide range of substrates using conventional spraying equipment. The sensor properties depend on the morphology of the composite and on the electrodes that are used to couple it to the charge amplifier. Electrodes of various kinds have been tested. Interaction between the electrode and the piezoelectric paint sometimes occurs (for example, the organic vehicle for spray-coated electrodes may interact with the paint binder). The morphologies of the piezoelectric paint and of the electrode materials have been studied using light optical microscopy and scanning electron microscopy to investigate the effect of different compositions and of different processing conditions (e.g., paint mixing schedule). Preliminary work is reported on the characteristics of the piezoelectric particles and on the effect of heat treatment applied to anneal out defects produced by milling. X-ray analysis and particle size analysis have been used to characterize the changes that take place on heat treatment. X-ray diffractometry has also been used to follow the effect of poling on the paint sensors. At the present state of development, sensors made using the paint have a dynamic range of at least 40–4000 microstrain and a bandwidth of at least 1 Hz–2 kHz, and piezoelectric coefficient d
31 of approximately 20 pC/N. The sensors are resistant to outdoor exposure and a successful field trial has been conducted. 相似文献
43.
A citation identity is a list of an author's citees ranked by how frequently that author has cited them in publications covered
by the Institute for Scientific Information. The same Dialog software that creates identities can simultaneously show the
overall citation counts of citees, which indicate their reputations. Using identities for 28 authors in several disciplines
of science and scholarship, I show that the reputational counts of their citees always have an approximately log-normal distribution:
citations to very famous names are roughly balanced by citations to obscure ones, and most citations go to authors of middling
reputation. These results undercut claims by constructivists that the main function of citation is to marshal “big-name” support
for arguments at the expense of crediting lesser-known figures. The results are better explained by Robert K. Merton's norm
of universalism, which holds that citers are rewarding use of relevant intellectual property, than by the constructivists'
particularism, which holds that citers are trying to persuade through manipulative rhetoric. A universalistic citation pattern
appears even in Alan Sokal's famous hoax article, where some of his citing was deliberately particularistic. In fact, Sokal's
basic adherence to universalism probably helped his hoax succeed, which suggests the strength of the Mertonian norm. In specimen
cases, the constructivists themselves are shown as conforming to it.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
44.
Role of ERAB/L-3-hydroxyacyl-coenzyme A dehydrogenase type II activity in Abeta-induced cytotoxicity
SD Yan Y Shi A Zhu J Fu H Zhu Y Zhu L Gibson E Stern K Collison F Al-Mohanna S Ogawa A Roher SG Clarke DM Stern 《Canadian Metallurgical Quarterly》1999,274(4):2145-2156
Endoplasmic reticulum-associated amyloid beta-peptide (Abeta)-binding protein (ERAB)/L-3-hydroxyacyl-CoA dehydrogenase type II (HADH II) is expressed at high levels in Alzheimer's disease (AD)-affected brain, binds Abeta, and contributes to Abeta-induced cytotoxicity. Purified recombinant ERAB/HADH II catalyzed the NADH-dependent reduction of S-acetoacetyl-CoA with a Km of approximately 68 microM and a Vmax of approximately 430 micromol/min/mg. The contribution of ERAB/HADH II enzymatic activity to Abeta-mediated cellular dysfunction was studied by site-directed mutagenesis in the catalytic domain (Y168G/K172G). Although COS cells cotransfected to overexpress wild-type ERAB/HADH II and variant beta-amyloid precursor protein (betaAPP(V717G)) showed DNA fragmentation, cotransfection with Y168G/K172G-altered ERAB and betaAPP(V717G) was without effect. We thus asked whether the enzyme might recognize alcohol substrates of which the aldehyde products could be cytotoxic; ERAB/HADH II catalyzed oxidation of a variety of simple alcohols (C2-C10) to their respective aldehydes in the presence of NAD+ and NAD-dependent oxidation of 17beta-estradiol. Addition of micromolar levels of synthetic Abeta(1-40) to purified ERAB/HADH II inhibited, in parallel, reduction of S-acetoacetyl-CoA (Ki approximately 1.6 microM), as well as oxidation of 17beta-estradiol (Ki approximately 3.2 microM) and (-)-2-octanol (Ki approximately 2.6 microM). Because micromolar levels of Abeta were required to inhibit ERAB/HADH II activity, whereas Abeta binding to ERAB/HADH II occurred at much lower concentrations (Km approximately 40-70 nM), the latter more closely simulating Abeta levels within cells, Abeta perturbation of ERAB/HADH II was likely to result from mechanisms other than the direct modulation of enzymatic activity. Cells cotransfected to overexpress ERAB/HADH II and betaAPP(V717G) generated malondialdehyde-protein and 4-hydroxynonenal-protein epitopes, which were detectable only at the lowest levels in cells overexpressing either ERAB/HADH II or betaAPP(V717G) alone. Generation of such toxic aldehydes was not observed in cells contransfected to overexpress Y168G/K172G-altered ERAB and betaAPP(V717G). We conclude that the generalized alcohol dehydrogenase activity of ERAB/HADH II is central to the cytotoxicity observed in an Abeta-rich environment. 相似文献
45.
OBJECTIVE: A mutant soybean line (A16) low in linolenic acid content (2% of oil by weight) was developed to increase oil oxidative stability. It was unknown whether serum lipid and lipoprotein concentrations in humans would be affected should A16 soybean oil (A16 oil) replace commercial soybean oil in diets. This study was conducted to examine the hypothesis that in free-living normolipidemic women, the consumption of A16 oil at approximately 10% of energy intake (en%) would not affect serum lipids and lipoproteins differently than would the consumption of the same amount of a commercial soybean oil with 7% of linolenic acid content. DESIGN: Fifteen free-living female college students consumed the soybean oil daily with regular meals for 9 weeks in different orders, with each test oil being eaten for 3 weeks. During the study, 13 en% was provided by each test oil and a total of 35 en% was from dietary fat. Serum concentrations of total cholesterol, high-density lipoprotein cholesterol (HDL cholesterol), low-density lipoprotein cholesterol (LDL cholesterol) and triacylglycerides (TAG) were measured. Serum total fatty acid patterns were analyzed as well. RESULTS: Each of the three test oils decreased serum total cholesterol, LDL cholesterol and TAG concentrations from the baseline values. The feeding of A16 and commercial soybean oils decreased serum HDL cholesterol significantly compared with coconut oil (p < 0.05). Dietary inclusion of coconut oil increased serum myristic acid significantly more than did either soybean oil (p < 0.01). Serum arachidonic acid concentrations were significantly greater with A16 consumption than with commercial soybean oil consumption (p < 0.001). CONCLUSION: A16 and commercial soybean oils both diminished serum HDL cholesterol. Although the fatty acid composition differed between the two soybean oils, A16 oil and commercial oil had similar effects on serum concentrations of lipoproteins and lipids. With increased oxidative stability, A16 oil is a good alternative to commercial soybean oil. 相似文献
46.
The use of porous polymer monoliths functionalized with silver nanoparticles is introduced in this work for high-sensitivity surface-enhanced Raman scattering (SERS) detection. Preparation of the SERS detection elements is a simple process comprising the synthesis of a discrete polymer monolith section within a silica capillary, followed by physically trapping silver nanoparticle aggregates within the monolith matrix. A SERS detection limit of 220 fmol for Rhodamine 6G is demonstrated, with excellent signal stability over a 24 h period. The capability of the SERS-active monolith for label-free detection of biomolecules was demonstrated by measurements of bradykinin and cytochrome c. The SERS-active monoliths can be readily integrated into miniaturized micrototal-analysis systems for online and label-free detection for a variety of biosensing, bioanalytical, and biomedical applications. 相似文献
47.
Application software for Intel's 8052AH-basic microcontroller can be developed in MCS basic-52, an enhanced version of basic, using the onchip basic interpreter. The paper explores the 8052AH-basic device and its language in comparison with the standard Microsoft basic and presents some software routines and other guidelines for programmers. Control-oriented applications, as opposed to conventional number-crunching applications, are emphasized. The paper also discusses how the resources of the Intellec development system can be used to facilitate the development of application software. 相似文献
48.
We describe a system for measurement of the dynamic mechanical properties of small bundles of myofibrils of muscle. Underwater fiber-optic sensing of tension via displacement of a quartz beam has been accomplished with a noise level of about 100 nanoNewtons in a bandwidth of 1 to 40 Hz. 相似文献
49.
Immobilisation of α-Amylase on Polyaromatic and Titanium Compounds Incorporating a Magnetic Material
Three methods of preparing immobilised α-amylase on supports which incorporate magnetic properties have been developed. The use of diazotized 1,3-diaminobenzene coated on magnetic iron oxide, which was itself either uncoated or coated with hydrous titanium (IV) oxide, was found to result in higher bound activities of the immobilised enzyme. The immobilised enzyme prepared from diazotized 1,3-diaminobenzene coated magnetic iron oxide support showed excellent stability towards freeze drying. A preparation of immobilised enzyme using magnetic iron coated with hydrous titanium (IV) oxide resulted in a greater thermostability. This support can be prepared in situ, overcoming the problem of loss of activity of the freeze dried immobilised enzyme. 相似文献
50.