Improving the sheared edge in the blanking of commercial AZ31 sheet through texture modification

Commercial rolled magnesium sheets of alloys AZ31 (Mg–3 mass%Al–1 mass%Zn) and ZE10 (Mg–1 mass% Zn–<1 mass% Rare Earths) in O-temper condition were used for blanking experiments near room temperature. A serrated fracture surface can be observed in case of AZ31 but not in case of ZE10. During the shearing process of the AZ31 sheet, many micro cracks parallel to the sheet plane are generated in the shearing zone. These micro cracks lead to the formation of loose particles during the shearing operation, which interfere with further processing of the part and incur additional costs by increasing the scrap rate.It is found that the strong basal texture of this alloy is an important reason for the generation of such serrated cracks. In this paper a new method of selective texture modification is described to locally change the mechanical properties of the AZ31 sheet. Subsequent shearing experiments show a significant change in the material behavior, especially regarding the direction of crack propagation, which leads to a better shearing performance. The commonly observed serrated crack does not occur any more after this local treatment and the sheared edge is clearly improved.     

Oral keratinocyte immune responses in HIV-associated candidiasis

Technetium-99m is the most commonly used radionuclide in routine nuclear medicine imaging procedures. Development of 99mTc-labeled receptor-specific imaging agents for studying the central nervous system is potentially useful for evaluation of brain function in normal and disease states. A novel 99mTc-labeled tropane derivative, [99mTc]TRODAT-1, which is useful as a potential CNS dopamine transporter imaging agent, was evaluated and characterized. After i. v. injection into rats, [99mTc]TRODAT-1 displayed specific brain uptake in the rat striatal region (striatum-cerebellum/cerebellum ratio 1.8 at 60 min), where dopamine neurons are concentrated. The specific striatal uptake could be blocked by pretreating rats with a dose of competing dopamine transporter ligand, beta-CIT (or RTI-55, i.v., 1 mg/kg). However, the specific striatal uptake of [99mTc]TRODAT-1 was not affected by co-injection of excess free ligand (TRODAT-1, up to 200 microg per rat) or by pretreating the rats with haloperidol (i.v., 1 mg/kg). The specific uptake in striatal regions of rats that had prior 6-hydroxydopamine lesion in the substantia nigra area showed a dramatic reduction. The radioactive material recovered from the rat striatal homogenates at 60 min after i.v. injection of [99mTc]TRODAT-1 showed primarily the original compound (>95%), a good indication of in vivo stability in brain tissue. Similar and comparable organ distribution patterns and brain regional uptakes of [99mTc]TRODAT-1 were obtained for male and female rats. Ex vivo autoradiography results of rat brain sections further confirmed the high uptake and retention of [99mTc]TRODAT-1 in the striatal region. In vitro binding studies measuring the affinity to dopamine transporters for the free ligand, TRODAT-1, and a nonradioactive rhenium derivative, Re-TRODAT-1, showed Ki values of 9.7 nM and 14.1 nM, respectively. Behavioral studies in rats using the free ligand, TRODAT-1 and Re-TRODAT-1 indicated that, unlike other tropane derivatives, they displayed no effect on locomotor activity, suggesting low toxicity. These results strongly support the conclusions that this novel 99mTc radioligand binds selectively to dopamine transporters in the brain and that is is potentially useful for in vivo assessment of the loss of dopamine neurons in Parkinson's and other neurodegenerative diseases.     

Nitric oxide synthase in neuroepithelial brain tumors

Immunohistochemical investigation of NO-synthase in brain astrocytic tumors revealed intense reaction in many tumor cells as well as direct correlation in the intensity of reaction and the degree of tumor anaplasia. Grade I astrocytomas did not show immunoreactivity in contrast to high anaplastic tumors where many cells had positive reaction with a different degree of intensity. Positive immunoreaction was shown in many giant cells. Small cell glioblastomas and oligodendrogliomas were immunonegative. There was a direct correlation between NO-synthase expression and glial fibrillar acidic protein.     

Reasserting the authority of science.

Argues that G. B. Melton (see record 1991-07135-001) misunderstood several aspects of the article by W. Gardner et al (see record 1989-32704-001) concerning the American Psychological Association's amicus briefs on adolescent abortion. The scope of a position presented for legal advocacy should depend on the quality of the empirical support for that stance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of carotid sinus denervation on fetal heart rate variation in normoxia, hypoxia and post-hypoxia in fetal sheep

BACKGROUND: Previous reports documented high rates of tobacco use among Alaska Natives (Eskimos, Indians, and Aleuts). In this population, tobacco use is the leading preventable cause of death. Lung cancer is the leading cause of cancer death among Alaska Natives and tobacco is responsible for over one-third of all cancer deaths in this population. Until recently there has been no systematic surveillance of the prevalence of tobacco use in this high-risk population. Data that did exist were not readily available to those primarily responsible for the health care of this population. This is the first time since 1990 that data on Alaska Natives have been collected in one analysis; this permits a more representative evaluation of tobacco use. METHODS: Data on tobacco use were obtained and analyzed from national and state surveys and selected research projects from 1988 to 1993. RESULTS: Alaska Natives have high prevalence of tobacco use, including both cigarettes and smokeless tobacco. Tobacco use prevalence among Alaska Natives exceeds that of Alaska non-Natives, U.S. whites, and American Indians/Alaska Natives in the United States outside of Alaska. Smoking prevalence among Alaska Native women is twice that of non-Native women in Alaska and nearly twice as high among pregnant Alaska Natives than pregnant non-Natives. Overall, prevalence of smokeless tobacco use was four times higher among Alaska Natives than comparative state and national populations. CONCLUSION: Because this population has such high rates of tobacco use, it is important to public health that monitoring and educational programs be in place and that data specific to Alaska Natives be made available.     

Test Engineering for CMOS Gate Arrays with the CAD-System VENUS 1

This paper describes the application of the computer-aided design/computer-aided testing (CAD/CAT) system VENUS 1 at Siemens for testing CMOS gate arrays [1]. The requirements for and the industrial aspects of CMOS gate array testing will be discussed.