全文获取类型
收费全文 | 519篇 |
免费 | 32篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 8篇 |
妇产科学 | 3篇 |
基础医学 | 86篇 |
口腔科学 | 30篇 |
临床医学 | 27篇 |
内科学 | 162篇 |
皮肤病学 | 10篇 |
神经病学 | 44篇 |
特种医学 | 19篇 |
外科学 | 62篇 |
综合类 | 5篇 |
预防医学 | 34篇 |
眼科学 | 2篇 |
药学 | 21篇 |
中国医学 | 1篇 |
肿瘤学 | 30篇 |
出版年
2023年 | 11篇 |
2022年 | 10篇 |
2021年 | 18篇 |
2020年 | 5篇 |
2019年 | 15篇 |
2018年 | 18篇 |
2017年 | 10篇 |
2016年 | 16篇 |
2015年 | 17篇 |
2014年 | 12篇 |
2013年 | 21篇 |
2012年 | 28篇 |
2011年 | 24篇 |
2010年 | 10篇 |
2009年 | 10篇 |
2008年 | 11篇 |
2007年 | 14篇 |
2006年 | 16篇 |
2005年 | 14篇 |
2004年 | 13篇 |
2003年 | 16篇 |
2002年 | 15篇 |
2001年 | 9篇 |
2000年 | 12篇 |
1999年 | 16篇 |
1998年 | 9篇 |
1997年 | 8篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1993年 | 4篇 |
1992年 | 16篇 |
1991年 | 12篇 |
1990年 | 7篇 |
1989年 | 8篇 |
1988年 | 4篇 |
1987年 | 12篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1983年 | 11篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1976年 | 3篇 |
1974年 | 9篇 |
1972年 | 8篇 |
1971年 | 6篇 |
1970年 | 5篇 |
1967年 | 4篇 |
1966年 | 3篇 |
排序方式: 共有552条查询结果,搜索用时 15 毫秒
1.
A total of 9 patients with macroscopic hematuria from various causes, none with evidence of disseminated intravascular coagulation, received low oral, divided doses (approximately 150 mg. per kg. per day) of epsilon aminocaproic acid for up to 21 consecutive days. The hematuria was controlled effectively without overt clinical reactions. Parameters of hepatic and renal function, indicators of muscular damage, were studied in detail in 3 patients. No significant abnormalities were found. The use of small doses of epsilon aminocaproic acid was not accompanied by significant complications and appeared to be effective in special situations for the control of urinary bleeding. This therapy may have indications in a number of urological states accompanied by excessive hematuria. 相似文献
2.
G Galella L Medini E Stragliotto P Stefanini P Rise E Tremoli C Galli 《Biochemical pharmacology》1992,44(4):715-720
Interleukin-1 (IL-1) can initiate the synthesis of prostaglandins which in turn act as endogenous modulators of IL-1 production. The human monocyte/macrophage synthesizes various eicosanoids through the activation of the cellular phospholipase system. Cell stimulation results in the activation of phospholipase A2 (PLA2) whose major substrate is phosphatidylcholine (PC) and the release of the eicosanoid precursor arachidonic acid (AA) from PC. Another pathway is the stimulation of a phospholipase C (PLC) mainly active on phosphoinositides and the resulting formation of inositol phosphates (IPs) and diacylglycerol (DAG). Phospholipids other than phosphoinositides can also be hydrolysed by PLC to give rise to DAG. Studies have shown that IL-1 does not activate the IP pathway, but it primarily stimulates a PLC linked to phosphatidylethanolamine in cultured rat mesangial cells, and a PLC linked to PC in Jurkart cells. We have stimulated human monocytes with IL-1 and calcium ionophore A23187 and we have observed their effect on the phospholipase system. The results indicate that IL-1 does not activate the formation of IPs in cells labeled with [3H]myo-inositol. In contrast, in cells labeled with [3H]AA, IL-1 causes the formation of DAG associated with the hydrolysis of PC. Moreover, after stimulation with IL-1 there is no accumulation of free AA which would indicate that there has been no activation of PLA2, which occurs instead with A23187 stimulation. These data suggest that, in monocytes, IL-1 does not directly stimulate a PLA2 or a PLC active on phosphatidylinositol; instead it primarily stimulates a PLC active on PC. 相似文献
3.
Angelo Stefanini 《Tropical medicine & international health : TM & IH》1997,2(3):278-283
After introducing the context in which health systems exist in developing as well as in industrialized countries, the author describes the role that hospitals are expected to play as 'enterprises'. The rationale behind such a role is explored and the experience so far available discussed. Evidence from several developing countries suggests caution and tends to discourage radical and indiscriminate introduction of market‐oriented reforms, which international donors seem to be spearheading in Africa's health systems. It is likely, however, that a limited, gradual introduction of selected elements of these reforms (such as some aspects of contracting out, managerial decentralization, the split between purchasing and providing functions) may find its place and eventually have a positive impact on the performance of the health systems. But the 'mystique of markets' must not be allowed to deprive public hospitals of the sense of social utility and of the caring ethos which are essential requisites of a meaningful and effective public health system. 相似文献
4.
Cockayne''s syndrome: correlation of clinical features with cellular sensitivity of RNA synthesis to UV irradiation. 总被引:6,自引:0,他引:6
下载免费PDF全文
![点击此处可从《Journal of medical genetics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A R Lehmann A F Thompson S A Harcourt M Stefanini P G Norris 《Journal of medical genetics》1993,30(8):679-682
Cockayne's syndrome (CS) is a rare autosomal recessive disorder with dwarfism, mental retardation, and otherwise clinically heterogeneous features. In cultured CS fibroblasts, the failure of RNA synthesis to recover to normal rates after UV-C irradiation provides a useful and relatively simple diagnostic test. We have measured post-UV-C RNA synthesis in 52 patients for whom a clinical diagnosis of CS was considered a possibility. Twenty-nine patients showed the defect characteristic of CS cells, and 23 had a normal response. We have attempted to correlate the cellular diagnosis with the different clinical features of the disorder. Clinical details of the patients were obtained from referring clinicians in the form of a questionnaire. Our results show that, apart from the cardinal features of dwarfism and mental retardation, sun sensitivity correlated best with a positive cellular diagnosis. Pigmentary retinopathy, gait defects, and dental caries were also good positive indicators, although several patients with a positive cellular diagnosis did not have these features. 相似文献
5.
Bottini N Otsu A Borgiani P Saccucci P Stefanini L Greco E Fontana L Hopkins JM Mao XQ 《Clinical genetics》2003,63(3):228-231
Protein tyrosine phosphatases (PTPases) have recently been recognized as important modulators of various signal transduction pathways in immune cells. Genetic polymorphisms have been described in genes codifying for members of this family of enzymes, and the genetics of PTPases is predicted to play an important role in the etiology of immune diseases and of their clinical variability. The low molecular weight protein tyrosine phosphatase (ACP1 or LMPTP) is one of the few PTPases with a known genetic polymorphism, and has been proposed to be associated with atopic dermatitis in a small sample from an Italian population. In this paper we describe the association of the ACP1 polymorphism with total IgE levels in two independent samples from English and Italian populations. In both the samples the mean value of serum IgE is lower among subjects carrying the BC genotype than in other ACP1 genotypes. The BC genotype is associated with the highest total ACP1 enzymatic activity. Our data suggest that one or both of the ACP1 isoforms exert an inhibitory role on some signal transduction pathway relevant for IgE hyperproduction. 相似文献
6.
Differential Expression of Matrix-Metalloproteinase-1 and -2 Genes in Normal and Fibrotic Human Liver 总被引:17,自引:9,他引:17
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
7.
Oral administration of the antithyroid drug methimazole (50 mg/kg per day) to rats during the last six days of pregnancy, and subsequent daily s.c. injection of methimazole (20-30 mg/kg) to their pups from birth to postnatal day 30 provoked hormonal and somatic alterations resembling (with all caution to any association between rodent and human data) those of congenital hypothyroidism. The steady-state concentrations of striatal dopamine were similar in hypothyroid and euthyroid, 32-day-old rats, while the levels of the dopamine metabolites 3,4-dihydroxyphenylacetic and homovanillic acids were markedly decreased in hypothyroidism. The results of this and our earlier study [Vaccari A. and Gessa G. L. (1989) Neurochem. Res. 14, 949-955] show that the maximal synaptosomal uptake of [3H]dopamine, an index for the density of nigrostriatal dopaminergic terminals, and the maximum number of membrane [3H]tyramine binding sites, reflecting the concentration of the vesicular transporter for dopamine, were decreased in the hypothyroid striatum. There was also a loss of those D1-type dopaminergic receptors claimed to be located on neurons intrinsic to the striatum, and, consequently, dopamine-stimulated, D1-regulated adenylate cyclase activity was depressed. It is suggested that individual dopaminergic nerve endings in the neonatal hypothyroid striatum must contain more dopamine, owing to some loss of pertinent innervation and, therefore, to the presence of less vesicular transport sites for dopamine. Hypothyroidism-related decreases in the maximum number of striatal D1- and, reportedly, D2-receptors, plus the impairment of D1-coupled second messenger activity, may play a role in the derangement of those neurobehavioural patterns where a dopaminergic regulation is putatively implied. 相似文献
8.
Xeroderma pigmentosum (XP) and Cockayne syndrome (CS) are two hereditary disorders in which photosensitivity is associated with distinct clinical and cellular phenotypes and results from genetically different defects. We have identified the primary molecular alteration in two patients in whom clinical manifestations strongly reminiscent of a severe form of XP were unexpectedly associated with the CS cellular phenotype and with a defect in the CSB gene. Sequencing of the CSB -coding region in both cDNA and genomic DNA showed that these patients had identical alterations to those in a patient with the clinical features of the classical form of CS. These data, together with fluorescence in situ hybridization analysis, demonstrated that the two siblings with XP as well as the CS patient were homozygous for the same CSB mutated allele, containing a silent C2830T change and a nonsense mutation C2282T converting Arg735 to a stop codon. The finding that the same inactivating mutation underlies different pathological phenotypes indicates that there is no simple correlation between the molecular defect and the clinical features. Therefore, alterations in the CSB gene give rise to the same repair defect at the cellular level but other genetic and/or environmental factors determine the pathological phenotype. 相似文献
9.
Stefanini ML Colli C Lerner BR Lei DL Chaves SP Di Pietro MS Oliveira AA Szarfarc SC 《Cadernos de saúde pública / Ministério da Saúde, Funda??o Oswaldo Cruz, Escola Nacional de Saúde Pública》1995,11(3):439-447
The authors studied a sample of students entering the first grade in the Osasco public school system in order to determine both the prevalence of anemia and nutritional status. Osasco is part of the Greater S o Paulo Metropolitan Area. Diagnosis of anemia was made through the hemoglobin concentration of blood from digital puncture. World Health Organization (WHO) levels were used to define anemia. Nutritional Status assessment. was made through weight/age and height/age indices, using Z score distribution and the National Center for Health Statistics (NCHS) reference levels. Prevalence of anemia was 51%. Prevalence levels varied according to the schools' geographic location: 56.9% in peripheral neighborhoods and 41.7% in central areas. Children with illiterate parents had a higher prevalence of this condition. Risk of anemia was higher for children who were over eight years of age when entering the first grade. Acute malnutrition was not found. Prevalence was higher than expected and points to the urgent need to establish an anemia control program for schoolchildren in this population. 相似文献
10.
Varrassi G Marinangeli F Agrò F Aloe L De Cillis P De Nicola A Giunta F Ischia S Ballabio M Stefanini S 《Anesthesia and analgesia》1999,88(3):611-616
We assessed the relative morphine consumption in a combined analgesic regimen (on-demand morphine plus the nonopioids propacetamol or ketorolac) after gynecologic surgery. Two hundred women randomly received two i.v. doses of propacetamol 2 g or ketorolac 30 mg in a double-blinded, double-dummy trial. Patients were monitored for 12 h, and the following efficacy variables were assessed: total dose of morphine, pain intensity, and global efficacy. Safety and tolerability were evaluated by the occurrence of adverse events, especially the presence and intensity of gastrointestinal symptoms. Hemostatic variables were measured 30 and 60 min after the first infusion; arterial blood pressure, heart and respiratory rates, sedation scores, and renal and hepatic function were also assessed. Total morphine requirements were not significantly different between the propacetamol (10.6 +/- 4.8 mg) and ketorolac (10.2 +/- 4.4 mg) groups. The evolution of pain intensity and the global efficacy also showed similar patterns in the two groups: 70.2% of patients in the propacetamol group rated the efficacy as "good/ excellent" compared with 68.2% in the ketorolac group. There were no clinically significant changes in vital signs or laboratory values and no observed differences between the two groups, although ketorolac slightly, but not significantly, prolonged the bleeding time. Epigastric pain was present in 9% and 15% of patients receiving propacetamol and ketorolac, respectively. There were two adverse events in the propacetamol group and four in the ketorolac group. Propacetamol demonstrates an efficacy similar to that of ketorolac and has an excellent tolerability after gynecologic surgery. IMPLICATIONS: Propacetamol and ketorolac, combined with patient-controlled analgesia morphine, show similar analgesic efficacy after gynecologic surgery. Morphine consumption and pain scores were comparable in the two studied groups. Propacetamol is as effective as ketorolac and has an excellent tolerability after gynecologic surgery. 相似文献