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101.
The paper is based on the analysis of 235 young and middle-age patients with non-traumatic cerebral hemorrhage. Tactics of treatment is determined for each group depending on bleeding localization in accordance with World Health Organization's classification (1981). Operative treatment is recommended for lateral site of hematomas of 25 cm3 and more signs of media structures dislocation of 5 mm and more. With the development of hypertension-hydrocephal syndrome surgical intervention is directed at its elimination and where possible at hematoma's ablation. The amount of operative interventions is limited in case of medial and mixed variants of hemorrhages especially when bleedings affect mesencephal structures. In conditions of a neurosurgical clinic a pharmacotherapy is used as an independent one, as a preparation for surgical treatment as well as during operation and in postoperative period. 相似文献
102.
This paper presents the analytical modeling of subthreshold current and subthreshold swing of short- channel fully-depleted (FD) strained-Si-on-insulator (SSOI) MOSFETs having vertical Gaussian-like doping pro- file in the channel. The subthreshold current and subthreshold swing have been derived using the parabolic approx- imation method. In addition to the effect of strain on silicon layer, various other device parameters such as channel length (L), gate-oxide thickness (tox), strained-Si channel thickness (ts_Si), peak doping concentration (Np), project range (Rp) and straggle (op) of the Gaussian profile have been considered while predicting the device characteris- tics. The present work may help to overcome the degradation in subthreshold characteristics with strain engineering. These subthreshold current and swing models provide valuable information for strained-Si MOSFET design. Ac- curacy of the proposed models is verified using the commercially available ATLASTM, a two-dimensional (2D) device simulator from SILVACO. 相似文献
103.
Ensemble of surrogates 总被引:5,自引:3,他引:2
Tushar Goel Raphael T. Haftka Wei Shyy Nestor V. Queipo 《Structural and Multidisciplinary Optimization》2007,33(3):199-216
The custom in surrogate-based modeling of complex engineering problems is to fit one or more surrogate models and select the
one surrogate model that performs best. In this paper, we extend the utility of an ensemble of surrogates to (1) identify
regions of possible high errors at locations where predictions of surrogates widely differ, and (2) provide a more robust
approximation approach. We explore the possibility of using the best surrogate or a weighted average surrogate model instead
of individual surrogate models. The weights associated with each surrogate model are determined based on the errors in surrogates.
We demonstrate the advantages of an ensemble of surrogates using analytical problems and one engineering problem. We show
that for a single problem the choice of test surrogate can depend on the design of experiments. 相似文献
104.
Robots are frequently used for operations in hostile environments. The very nature of these environments, however, increases the likelihood of robot failures. Common failure-tolerance techniques rely on effective failure detection and identification. Since a failure may not always be successfully identified, or, even if identified, may not be identified soon enough, it becomes important to consider the behavior of manipulators with unidentified failures. This work investigates the behavior of robots experiencing unidentified locked-joint failures in a general class of tasks characterized by point-to-point motion. Based on the analysis, a procedure for workspace evaluation is developed that allows for the identification of regions in the manipulator's workspace in which tasks may be completed even with such failures. © 2005 Wiley Periodicals, Inc. 相似文献
105.
NS Ponomareva OG Voskresenskaia AA Kamenski? VP Golubovich IP Ashmarin 《Canadian Metallurgical Quarterly》1998,48(3):471-477
Ethinylestradiol (EE) has evident paradoxical effects on cancer risk for human breast and hepatic cancer which parallel in some respects its effects on estrogen-induced neoplasms in the hamster kidney and liver. EE has been shown to be only weakly carcinogenic in the hamster kidney, but the most potent carcinogenic estrogen in the hamster liver following prolonged treatment. Unexpectedly, when EE and potent carcinogenic estrogens, such as diethylstilbestrol (DES), 17beta-estradiol (E2) and Moxestrol (MOX), are administered concomitantly, estrogen-induced carcinogenesis in the kidney is completely prevented. In studying this novel finding, we found that, compared with E2 exposure alone, EE at 0.05 and 1.0 nM significantly (P < 0.001) inhibited the rise in proliferation of cultured primary hamster proximal renal tubular (PRT) cells in the presence of E2 (1.0 nM). Consistent with these findings, combined EE + DES treatment for 5.0 months reduced hamster kidney c-myc, c-fos and c-jun RNA expression to 43, 37 and 52%, respectively, compared with levels observed after DES treatment alone. Interestingly, TAM + DES treatment for the same period also resulted in the same low level of RNA expression of these proto-oncogenes. c-MYC, c-FOS and c-JUN protein products were comparably reduced after either EE + DES or TAM + DES treatment. It appears that c-fos expression and c-FOS protein levels in the hamster kidney were more responsive to TAM inhibition. These data demonstrate that EE possesses unique anti-tumorigenic properties in vivo in the hamster kidney. Additionally, the observed anti-estrogen-like effect of EE on cell proliferation of cultured PRT cells suggests that EE may interfere critically with estrogen receptor (ER)-mediated mitogenic pathway(s) affected by potent carcinogenic estrogens, thus preventing subsequent gene dysregulation and, hence, tumor development. Based on competition studies, the differential binding of EE to hamster kidney ER relative to that of the other estrogens (E2, DES, MOX) appears not to contribute to the prevention of estrogen carcinogenesis at this organ site by EE. 相似文献
106.
107.
Selective lesion of the serotoninergic system diminished the synaptic uptake of 3H-L-glutamic acid and 3H-DL-aspartic acid, as well as the Na+(-dependent) binding of 3H-L-glutamic acid in the cortex and the brain stem. The data obtained suggest an ability of the serotoninergic system to modify presynaptic processes in amino-acidergic neurons of the CNS. 相似文献
108.
H Rivera AI Vassquez ML Ayala-Madrigal ML Ramirez-Due?as IP Davalos 《Canadian Metallurgical Quarterly》1996,39(4):236-239
In 1984 the Dental Attitude Questionnaire (DAQ), an instrument for assessing various aspects of a person's attitude toward oral health care, was presented by STOCKWELL & BANTING. The DAQ consists of six content scales, Cynicism, Health Concern, Motivation, Oral Function, Social Aesthetic and Susceptibility, and two validity scales, Halo and Infrequency. A Dutch translation was presented in 1986 by HOOGSTRATEN & BROERS. In order to replicate the factor analysis on the original DAQ as reported by STOCKWELL & BANTING, the present study was undertaken. The results show a change in factor structure from a three factor solution to a two factor solution. A confirmatory factor analysis shows that the original three factor structure of the DAQ is not present in the data collected with the translated version. To account for this change, some possible reasons are discussed. 相似文献
109.
YZ Ling JS Li K Kato Y Liu X Wang GT Klus K Marat IP Nnane AM Brodie 《Canadian Metallurgical Quarterly》1998,6(10):1683-1693
Some epimeric 20-hydroxy, 20-oxime, 16 alpha, 17 alpha-, 17,20- and 20,21-aziridine derivatives of progesterone were synthesized and evaluated as inhibitors of human 17 alpha-hydroxylase/C17,20-lyase (P450(17) alpha) and 5 alpha-reductase (5 alpha-R). The reduction of 16-dehydropregenolone acetate (3a) was reinvestigated. NaBH4 in the presence of CeCl3 gave better stereo-selectivity for 20 beta-ol [20 alpha/20 beta-OH (4 alpha/4 beta) = 1/2.7] than LTBAH or the Meerwein-Pondroff method reported; reduction with Zn in HOAc formed exclusively 20 alpha-ol (4 alpha b). The 20 alpha- and 20 beta-hydroxy-4,16-pregnadien-3-one (9 alpha) and (9 beta) were synthesized from the alcohols 4 alpha b and 4 beta b. Several 20-oxime pregnadienes and 16 alpha, 17 alpha-, 17,20- and 20,21-aziridinyl-5-pregnene derivatives were also synthesized. LiAlH4 reduction of the 16-en-20-oxime (12b) yielded 20 (R)-(13a) and 20(S)-17 alpha,20-aziridine (13b) and 20(R)-17 beta,20-aziridine (14a). Several compounds inhibited the human P450(17) alpha with greater potency than ketoconzole. The 5 alpha-R enzyme assay showed that while (9 alpha) did not have any activity, (9 beta) and (3b) were potent 5 alpha-reductase (IC50 = 21 and 31 nM) inhibitors with activities similar to finasteride. The 20-oximes (17a) and (17b) were potent dual inhibitors for both 5 alpha-R (IC50 = 63 and 115 nM, compared to 33 nM for finasteride) and P450(17) alpha (IC50 = 43 and 25 nM, compared to 78 nM for ketoconazole). 相似文献
110.
SN Nagornev SI Sytnik IP Bobrovnitski? IN Cherniakov AA Shishov 《Canadian Metallurgical Quarterly》1996,(7):53-60
In simulating acute hypoxic hypoxia with the participation of male volunteers, the authors investigated the antihypoxic and antioxidative activity of metabolic drugs (jakton, amtizole succinate, nootropil, probucol, and a mixture which consists of jakton, amtizole succinate, and probucol). The pharmaceuticals were shown to have heterodirectional effects on lipid peroxidative processes. Drugs having a pronounced antioxidative activity (such as probucol and the mixture) promotes oxygen utilization during hypoxia and posthypoxic reoxygenation chiefly by the oxygenase pathway. This rearrangement of oxygen utilization processes caused an increase in human high-altitude resistance. The use of the above drugs is a promising trend in the development of an adaptative response to hypoxia in persons engaged in hazardous jobs. 相似文献