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991.
Swanlata Soni Sanjay K. Jain N. K. Jain 《Drug development and industrial pharmacy》1992,18(10):1127-1135
In vitro skin permeation of Timolol maleate through human cadaver skin was studied using Franz diffusion cell. The results indicate that the drug penetrates poorly through human cadaver skin. However, skin penetration enhancers such as dimethyl sulfoxide (DMSO), oleic acid (OA) and lauryl chloride (LC) enhanced the permeability of Timolol maleate (TM) through human cadaver skin. The permeation enhancement of drug was maximum by lauryl chloride amongst the three enhancers. Moreover, lauryl chloride increases the permeation of drug through skin with increase in the time of application and concentration on skin. The change in lag time was also observed. 相似文献
992.
V. K. Jain Amita Gupta A. Kumar G. K. Singhal O. P. Arora T. Srinivasan D. S. Ahuja P. P. Puri Vikram Kumar 《Bulletin of Materials Science》1993,16(3):239-241
We report the first operation of light emittingp-n junction diode in porous silicon fabricated by diffusion. 相似文献
993.
This paper presents asymmetrical pulse-width-modulated (APWM) DC/DC resonant converter topologies that exhibit near-zero switching losses while operating at constant and very high frequencies. The converters include a bridged chopper to convert the DC input voltage to a high-frequency unidirectional AC voltage, which in turn is fed to a high-frequency transformer through a resonant circuit. The bridged chopper has two switches that alternately conduct. The duty cycles of the conduction of the switches are complementary with one another and are varied to control the output voltage. Three resonant circuit configurations suitable for this type of control are presented. Frequency domain analysis of the converter is given, and performance characteristics are presented. Experimental results for a 48-5 V, 30 W converter show an efficiency of 88% at a constant operating frequency of 1 MHz 相似文献
994.
In this study, the experiments were conducted from December 2000 to November 2001 to evaluate solar fraction (Fn) for quonset type empty greenhouse. Solar radiation was measured at different points inside and outside the greenhouse weekly once. The model based on Auto-CAD 2000 has been used for a given solar altitude and azimuth angles. Calculations have also been carried out for a typical day of each month of the year. It is observed that the solar fraction obtained by using Auto-CAD 2000 are very close to the value determined by using experimental observations and its value is more during winter months. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
995.
Computerized flow field analysis: oriented texture fields 总被引:9,自引:0,他引:9
Rao A.R. Jain R.C. 《IEEE transactions on pattern analysis and machine intelligence》1992,14(7):693-709
996.
WA Zatonski AB Lowenfels P Boyle P Maisonneuve HB Bueno de Mesquita P Ghadirian M Jain K Przewozniak P Baghurst CJ Moerman A Simard GR Howe AJ McMichael CC Hsieh AM Walker 《Canadian Metallurgical Quarterly》1997,89(15):1132-1138
BACKGROUND: There are few previous epidemiologic studies of gallbladder cancer, a rare but nearly always lethal gastrointestinal cancer with a demonstrated greater frequency in adult women and older subjects of both sexes, and also in the members of populations throughout central and eastern Europe and certain racial groups such as native American Indians. Unfortunately, the prospects for the prevention of this form of cancer are poor. PURPOSE: Our purpose in conducting this study was to investigate possible new risk factors for gallbladder cancer and to strengthen our understanding of established causal agents that may be involved in this disease. METHODS: A large, collaborative, multicenter, case-control study of cancer of the gallbladder was conducted in five centers located in Australia (Adelaide), Canada (Montreal and Toronto), The Netherlands (Utrecht), and Poland (Opole) from January 1983 through July 1988. Case subjects with gallbladder cancer were accrued by the centers from hospital pathology records and from reports to regional cancer registries. Cancer diagnosis was confirmed by either biopsy, cholecystectomy, or at the time of autopsy. Control subjects were randomly assigned at each center from the population. The pooled analysis included 196 case subjects and 1515 control subjects (who did not report previous cholecystectomy). Ninety-eight percent of the subjects were white. Personal interviews of case subjects, control subjects, and surrogates (spouse or next of kin) were conducted by trained personnel. RESULTS: After adjusting for potential confounding factors (age, sex, center, type of interview, years of schooling, alcohol intake, and lifetime cigarette smoking), a history of gallbladder symptoms requiring medical attention (e.g., reduced bile secretion from the gallbladder into the small intestine due to obstructions of the common bile or cystic ducts) was the major risk factor associated with this form of cancer (odds ratio [OR] = 4.4; 95% confidence interval [CI] = 2.6-7.5). This association was present even in subjects who had their first gallbladder examination because of symptoms present more than 20 years earlier (OR = 6.2; 95% CI = 2.8-13.4). Other variables associated with gallbladder cancer risk included an elevated body mass index, high total energy intake, high carbohydrate intake (after adjustment for total energy intake), and chronic diarrhea. All of these risk factors have been previously associated with gallstone disease. CONCLUSIONS: These findings are consistent with a major role of gallstones, or risk factors for gallstones, in the cause of gallbladder cancer. Additional information on whether or not screening high-risk subjects for gallstones or gallbladder cancer is needed. 相似文献
997.
In this paper, an asymmetrical pulse-width-modulated (APWM) resonant inverter topology is presented for high frequency AC power distribution systems. The inverter system is comprised of simple power and control circuitry. The detailed analysis shows that the proposed inverter has very low total harmonic distortion, near-zero switching losses, and fast transient response. A design procedure is illustrated as well. Simulation and experimental results are presented to prove the performance of the proposed inverter. 相似文献
998.
Overgeneralization is a major issue in the identification of grammars for formal languages from positive data. Different formulations
of generalization and specialization strategies have been proposed to address this problem, and recently there has been a
flurry of activity investigating such strategies in the context of indexed families of recursive languages. The present paper
studies the power of these strategies to learn recursively enumerable languages from positive data. In particular, the power
of strong-monotonic, monotonic, and weak-monotonic (together with their dual notions modeling specialization) strategies are
investigated for identification of r.e. languages. These investigations turn out to be different from the previous investigations
on learning indexed families of recursive languages and at times require new proof techniques. A complete picture is provided
for the relative power of each of the strategies considered. An interesting consequence is that the power of weak-monotonic
strategies is equivalent to that of conservative strategies. This result parallels the scenario for indexed classes of recursive
languages. It is also shown that any identifiable collection of r.e. languages can also be identified by a strategy that exhibits
the dual of weak-monotonic property. An immediate consequence of the proof of this result is that if attention is restricted
to infinite r.e. languages, then conservative strategies can identify every identifiable collection.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
999.
A. K. Jain R. G. Kasilingam S. D. Bhole 《The International Journal of Advanced Manufacturing Technology》1991,6(3):232-245
In this paper, we address the problem of planning the requirements of some of the important resources in flexible manufacturing
systems. Specifically, we model the problem of estimating the required numbers and types of machines and tools in the context
of a cellular layout. A two-stage procedure is developed which first forms the part families, using the complete-linkage clustering
method based on a new similarity index defined in terms of the tooling requirements, and then subsequently estimates the resource
requirements to manufacture the part families using an integer programming model. Several variations of the model are discussed
and a numerical example is given. 相似文献
1000.
Pregnancies in outbred mammals may be regarded as successfully developed homografts. One of the hypotheses that attempts to answer the enigma of why the fetus is not rejected (fetal-maternal relationships are based on reciprocal expressions of foreign transplantation antigens) claims for the existence of possible evolutionary links between invertebrate allorecognition and mammalian implantation, based on some cellular similarities. This essay further discusses the possible evolutionary perspectives between vertebrates and invertebrates alloimmunities from a different viewpoint. We discuss similarities between natural transplantation in colonial marine invertebrates, which are followed by chimerism and a state of tolerance, and two natural transplantation events in the mammalian systems which both have records for prolonged chimerism and tolerance: the phenomenon of dizygotic twin fusions and the situation of fetal cells implantation. Earlier comparative evolutionary perspectives are revisited. 相似文献