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排序方式: 共有105条查询结果,搜索用时 15 毫秒
91.
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We estimated the relationship between weight status and earnings among women participating in the Cebu Longitudinal Health and Nutrition Surveys between 1983 and 2002 conducted in Cebu, Philippines. Women working for pay were selected for the analysis. We used fixed effects estimation to account for unobserved time invariant characteristics related to weight. After correcting for potential bias due to unobserved heterogeneity, our results suggest that the earnings of obese or overweight women in Cebu (Philippines) were not less than women of normal weight. The relation between earnings and weight exists only among self-employed women or women working in more than one type of activity. No discrimination was found among women working for wages or per piece rate. In contrast, among self-employed and women working in more than one type of activity we found that underweight women earn less than do those with normal weight.  相似文献   
93.
Conscious cats were used to examine the effectiveness of the interleukin-1 receptor antagonist against the fever induced by interleukin-1 and endotoxin. Although inactive by itself, the antagonist (three 1-micrograms bolus injections at 10-min intervals), injected into the third ventricle, attenuated the febrile response to a subsequent intracerebroventricular bolus of interleukin-1. The rise in prostaglandin E2 levels in cerebrospinal fluid, which is a characteristic feature of fever, was curtailed as well. The interleukin-1 antagonist had little or no inhibitory effect on the response to an intracerebroventricular bolus of endotoxin, even though a higher dose was employed (2-micrograms bolus injections given three times at 10-min intervals and six times at 30-min intervals, respectively, before and after endotoxin administration). At either dosage, the intracerebroventricular antagonist was completely ineffective against an intravenous bolus injection of interleukin-1 or endotoxin and both fever and prostaglandin E2 elevation developed unabated. We conclude that brain receptors mediating the pyrogenic action of centrally injected interleukin-1 are susceptible to the antagonist. The same receptors, however, are seemingly not activated by systemic pyrogens. Our findings are consistent with the concept of circulating interleukin-1 acting outside the blood-brain barrier in the normal sequence of fever.  相似文献   
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Some scholars have suggested that an inverse care law holds for infant mortality--that infant mortality reductions are more rapid in regions with lower infant mortality. This theory has not been subjected to proper quantitative analysis. This paper examines time series data on infant mortality from 21 countries to test whether percentage reductions in infant mortality are larger when infant mortality is lower. We apply the Dickey-Fuller generalized least squares (DFGLS) unit root test to infant mortality rate (IMR) time series data from 21 mostly European nations for 1870-1988 to test the statistical significance of beta in a regression analysis of Deltaln IMR(t)=alpha+beta ln IMR(t-1)+epsilon(t). Evidence that beta is significant and negative would support the claim that infant mortality declines more rapidly when substantial mortality reductions have already been achieved. With the preferred specification, the DFGLS unit root test rejected the inverse benefit hypothesis in all countries except the Netherlands at the 5% and 10% cutoffs and Australia at the 10% cutoff. The rejection of the inverse benefit hypothesis was robust to alternative specifications of the lag structure of IMR and to transformations of IMR other than logarithmic. Based on late 19th and 20th century data from countries in Europe and Latin America, there is scarce evidence that percentage reductions in infant mortality are generally smaller in higher mortality countries. These findings suggest that large percentage reductions in infant mortality are possible for countries at any stage in economic development and are reflective of durable advances in human knowledge, social institutions and physical capital.  相似文献   
96.
NAD+ and its derivatives NADH, NADP+, and NADPH are essential cofactors in redox reactions and electron transport pathways. NAD serves also as substrate for an extensive series of regulatory enzymes including cyclic ADP-ribose hydrolases, mono(ADP-ribosyl)transferases, poly(ADP-ribose) polymerases, and sirtuin deacetylases which are O-acetyl-ADP-ribosyltransferases. As a result of the numerous and diverse enzymes that utilize NAD as well as depend on its synthesis and concentration, significant interest has developed in its role in a variety of physiologic and pathologic processes, and therapeutic initiatives have focused both on augmenting its levels as well as inhibiting some of its pathways. In this article, we examine the biosynthesis of NAD, metabolic processes in which it is involved, and its role in aging, cancer, and other age-associated comorbidities including neurodegenerative, cardiovascular, and metabolic disorders. Therapeutic interventions to augment and/or inhibit these processes are also discussed.Impact statementNAD is a central metabolite connecting energy balance and organismal growth with genomic integrity and function. It is involved in the development of malignancy and has a regulatory role in the aging process. These processes are mediated by a diverse series of enzymes whose common focus is either NAD’s biosynthesis or its utilization as a redox cofactor or enzyme substrate. These enzymes include dehydrogenases, cyclic ADP-ribose hydrolases, mono(ADP-ribosyl)transferases, poly(ADP-ribose) polymerases, and sirtuin deacetylases. This article describes the manifold pathways that comprise NAD metabolism and promotes an increased awareness of how perturbations in these systems may be important in disease prevention and/or progression.  相似文献   
97.
Metabolism of prostaglandin E1 (PGE1) and F (PGF) was studied in the frog spinal cord, using a hemisected preparation in vitro and tissue homogenates (whole honiogenate and tissue fractions). In the intact tissue, PGE, was converted to three Metabolites, 1 to 111, whereas only Metabolites 11 and 111 werc detected in experiments with PGF. Work with tissue homogenatcs confirmed that PG transformation is enzymatic, and endproducts were identified as PGF (Metabolite 1), 15-kcto metabolite (Metabolite 11) and 15-keto-13,14-dihydro metabolite (Metabolite 111). The 15-keto-13,14-dihydro metabolite was formed via the 15-keto metabolite which is consistent with findings elsewhere. These results establish the presence in the frog spinal cord of two pathways for PG metabolism, consisting one of the 15-hydroxy prostaglandin dehydrogenase (15-PGDH) and the prostaglandin-A13- reductase (13-PGR), the other of the prostaglandin E 9-keto(α)-reductase (9K-PGR). 9K-PGR is regarded as an inactivating enzyme because amphibian spinal neurons are less responsive to PGF, than to PGE1. In the intact or in the homogenized tissue, PGE, is metabolized more efficiently by the 15-PGDH/13-PGR than by the 9K-PGR route. The 15-PGDH metabolizes PGE, more readily than PGF. The present findings, together with the previous demonstration of active PG synthesis in the tissue and the potent actions of exogenous PGs, strongly suggest that the PGs play an important role in the function of neurons in the frog spinal cord.  相似文献   
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Two ELISA systems for the detection of human rotaviruses were developed. In the first system antibodies to Nebraska calf diarrhea virus (NCDV) were used for coating the solid matrix and for the preparation of the enzyme conjugate. In the second system antibodies to human rotavirus and antibodies to simian rotavirus (SA11) were used for coating the solid matrix and for the preparation of the enzyme conjugate respectively. The second ELISA system proved to have a broader spectrum for the detection of human rotaviruses. By using the two ELISA systems, the different types of human rotavirus could be distinguished. The ELISA tests developed were 8 to 64 times as sensitive as electron microscopy (EM) and (or) counterimmunoelectrophoresis (CIEP). The antigen detected by ELISA was shown to be different from that detected by the hemagglutination test.  相似文献   
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