首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2605篇
  免费   173篇
  国内免费   10篇
医药卫生   2788篇
  2022年   16篇
  2021年   33篇
  2020年   27篇
  2019年   35篇
  2018年   42篇
  2017年   41篇
  2016年   47篇
  2015年   45篇
  2014年   70篇
  2013年   107篇
  2012年   159篇
  2011年   169篇
  2010年   93篇
  2009年   94篇
  2008年   146篇
  2007年   148篇
  2006年   142篇
  2005年   126篇
  2004年   118篇
  2003年   123篇
  2002年   127篇
  2001年   51篇
  2000年   65篇
  1999年   61篇
  1998年   36篇
  1997年   31篇
  1996年   36篇
  1995年   27篇
  1994年   27篇
  1993年   17篇
  1992年   31篇
  1991年   47篇
  1990年   27篇
  1989年   27篇
  1988年   33篇
  1987年   35篇
  1986年   25篇
  1985年   22篇
  1984年   24篇
  1983年   15篇
  1982年   14篇
  1981年   18篇
  1980年   16篇
  1979年   29篇
  1978年   14篇
  1974年   10篇
  1973年   10篇
  1969年   11篇
  1968年   10篇
  1967年   10篇
排序方式: 共有2788条查询结果,搜索用时 15 毫秒
81.
Hepatocellular carcinoma is the main liver-related cause of death in patients with compensated cirrhosis. The early phases are asymptomatic and the prognosis is poor, which makes prevention essential. We propose that non-selective beta-blockers decrease the incidence and growth of hepatocellular carcinoma via a reduction of the inflammatory load from the gut to the liver and inhibition of angiogenesis.  相似文献   
82.
Translocations affecting chromosome subband 6p25.3 containing the IRF4 gene have been recently described as characteristic alterations in a molecularly distinct subset of germinal center B‐cell‐derived lymphomas. Secondary changes have yet only been described in few of these lymphomas. Here, we performed array‐comparative genomic hybridization and molecular inversion probe microarray analyses on DNA from 12 formalin‐fixed paraffin‐embedded and two fresh‐frozen IRF4 translocation‐positive lymphomas, which together with the previously published data on nine cases allowed the extension of copy number analyses to a total of 23 of these lymphomas. All except one case carried chromosomal imbalances, most frequently gains in Xq28, 11q22.3‐qter, and 7q32.1‐qter and losses in 6q13‐16.1, 15q14‐22.31, and 17p. No recurrent copy‐neutral losses of heterozygosity were observed. TP53 point mutations were detected in three of six cases with loss of 17p. Overall this study unravels a recurrent pattern of secondary genetic alterations in IRF4 translocation‐positive lymphomas. © 2012 Wiley Periodicals, Inc.  相似文献   
83.
About 20% of ovarian carcinomas show alterations of 19p13 and/or 19q13 in the form of added extra material whose origin often is from chromosome 11. Based on earlier spectral karyotype analysis of the ovarian cancer cell line SKOV‐3, which shows an unbalanced translocation der(19)t(11;19), the aim of this study was to determine the precise breakpoints of that derivative chromosome. After rough delimitation of the breakpoints of microdissected derivative chromosomes by array analysis, we designed a matrix of primers spanning 11q13.2 and 19p13.2 detecting multiple amplicons on genomic and cDNA. Sequencing the amplicons, accurate localization of both breakpoints on both chromosomes was possible and we found that exon 14 of HOOK2 from chromosome 19 and exon 2 of ACTN3 from chromosome 11 were fused in the derivative chromosome. The breakpoint in the HOOK2 gene was in an intrinsic triplet of nucleic acids leading to a shift in the ACTN3 reading frame in the derivative chromosome. This frameshift alteration should give rise to an early stop codon causing a loss of function of ACTN3. Signals in two‐dimensional Western blotting exactly match to calculated molecular mass and the isoelectric point of the fusion protein. © 2013 Wiley Periodicals, Inc.  相似文献   
84.
Recently, the Dopamine D4 Receptor Gene (DRD4) and the Serotonin Transporter Gene (5-HTT) have been found to be candidate genes for infant attachment disorganization. The present study aimed to explore the relationship of these genes to adult attachment representations. The Adult Attachment Interview was used to assess attachment representations in 167 German adults. DNA from buccal cells was genotyped for the DRD4 VNTR Exon III and 5-HTT LPR polymorphisms with respect to the presence of the 7repeat allele and the short allele, respectively. DRD4 7repeat allele carriers were significantly more likely to be securely attached than those without 7repeat but only for subjects with unloving caregiver recollections. No association between the 5-HTT LPR polymorphism and adult attachment was found. These findings encourage further investigations to explore endophenotypical and mediating psychological processes between the DRD4 Gene and secure attachment patterns.  相似文献   
85.
86.

Background

Ethiopia is a country in which child and adolescent mental health needs are often not met. In order to promote capacity building, a Collaborative International Exchange Programme has been established between Jimma University at Jimma, Ethiopia, and Ludwig-Maximilian University in Munich, Germany. The programme focuses on training non-physician health professionals in mental health speciality. One of the courses in the training programme, child psychiatry, involves a child psychiatrist and a children’s nurse supporting the management of a patient described in this case report. Its conceptual framework is based on the section “significant emotional and medically unexplained complaints” of the “WHO mental health GAP intervention guide for mental, neurological and substance use disorders in non-specialized health settings”.

Objective

The purpose of this case report is to promote confidence in mental health professionals when managing patients with similar conditions, and to stimulate further evaluation of the conceptual approach in developing countries.

Patient

The subject of this case report is a 14-year-old adolescent girl admitted to the psychiatric clinic at Jimma University Teaching Hospital. She was admitted for intractable retching, inability to eat, weight loss, and inability to walk. Challenges included the combination of medical and psychiatric symptoms, and the significant impairment of functioning in this adolescent. The first aim in the management of this patient was to guarantee vital functions. In a problem-oriented approach, different domains were addressed to restore nutritional, social, emotional, and motor functions. Treatment consisted of various elements of psychosocial interventions. The patient improved in 2 weeks and the final diagnosis was conversion disorder.

Conclusion

Psychosocial interventions can be developed in cooperation, and applied in a setting where little child mental health expertise is available. Case-based learning relying on local expertise is suitable in meeting local needs and in developing mental health services for children and adolescents.
  相似文献   
87.
AIMS: We investigated the value of a novel early biomarker, heart-type fatty acid-binding protein (H-FABP), in risk stratification of patients with acute pulmonary embolism (PE). METHODS AND RESULTS: We prospectively included 107 consecutive patients with confirmed PE. The endpoints were (i) PE-related death or major complications and (ii) overall 30-day mortality. Overall, 29 patients (27%) had abnormal (>6 ng/mL) H-FABP levels at presentation. Of those, 12 (41%) had a complicated course, whereas all patients with normal baseline H-FABP had a favourable 30-day outcome (OR, 71.45; P<0.0001). At multivariable analysis, H-FABP (P<0.0001), but not cardiac troponin T (P=0.13) or N-terminal pro-brain natriuretic peptide (P=0.36), predicted an adverse outcome. Evaluation of a strategy combining biomarker testing with echocardiography revealed that patients with a negative H-FABP test had an excellent prognosis regardless of echocardiographic findings. In contrast, patients with a positive H-FABP test had a complication rate of 23.1% even in the presence of a normal echocardiogram, and this rose to 57.1% if echocardiography also demonstrated right ventricular dysfunction (OR vs. a negative H-FABP test, 5.6 and 81.4, respectively). CONCLUSION: H-FABP is a promising early indicator of right ventricular injury and dysfunction in acute PE. It may help optimize risk stratification algorithms and treatment strategies.  相似文献   
88.
The human histiocytic cell line U937, which expresses a number of monocyte markers and properties, was investigated with regard to its ability to be activated for NO and tumor necrosis factor (TNF) release after treatment with alkylphosphocholines (APC) and APC liposomes. Using APC multilamellar vesicles (MLV) a clear dose-dependent increase of NO production could be demonstrated for U 937 cells, whereas the corresponding soluble substances had no effect. The time course of NO release was characterised by a peak between 2 h and 12 h and a strong decrease after 24 h. LPS caused no NO release nor the production of TNF in U 937 cells. The simultaneous incubation of the cells with lipopolysaccharide and APC or APC-MLV, led to a strong increase in TNF production. Closer investigation of the time sequence of this synergistic effect demonstrated that cells, that had first been treated with hexadecylphosphocholine (HPC)-MLV and 4 h later with lipopolysaccharride secreted significantly more TNF into the supernatants than in the experiment where both substances were added simultaneously. From these results it was concluded that APC-MLV are possibly able to act as a primer in the process of lipopolysaccharide mediated TNF induction. Furthermore, a positive influence of phorbol 12-myristate 13-acetate (PMA) on the ability of U 937 cells to produce TNF following a treatment with HPC or HPC-MLV could be observed. PMA-pretreated cells were shown to release much more TNF compared to control cells, which led to the supposition that the immunomodifying activity of APC becomes effective only in more highly differentiated cell types.Abbreviations APC alkylphosphocholines - DPC dodecylphosphocholine - HPC hexadecylphosphocholine - TPC tetradecylphosphocholine - MLV multilamellar vesicles - PMA phorbol 12-myristate 13-acetate - TNF tumour necrosis factor Partly supported by the Bundesministerium für Forschung und Technologie (9319564A)  相似文献   
89.
OBJECTIVE: The study was performed to investigate the effect of improving metabolic control with pioglitazone in comparison to glimepiride on microvascular function in patients with diabetes mellitus type 2. METHODS: A total of 179 patients were recruited and randomly assigned to one treatment group. Metabolic control (HbA1c), insulin resistance (HOMA index), and microvascular function (laser Doppler fluxmetry) were observed at baseline and after 3 and 6 months. RESULTS: HbA1c improved in both treatment arms (pioglitazone: 7.52 +/- 0.85% to 6.71 +/- 0.89%, p < .0001; glimepiride: 7.44 +/- 0.89% to 6.83 +/- 0.85%, p < .0001). Insulin-resistance decreased significantly in the pioglitazone group (6.15 +/- 4.05 to 3.85 +/- 1.92, p < .0001) and remained unchanged in the glimepiride group. The microvascular response to heat significantly improved in both treatment groups (pioglitazone 48.5 [15.2; 91.8] to 88.8 [57.6; 124.1] arbitrary units [AU], p < .0001; glimepiride 53.7 [14.1; 91.9] to 87.9 [52.9, 131.0] AU, p < .0001, median [lower and upper quartile]). Endothelial function as measured with the acetylcholine response improved in the pioglitazone group (38.5 [22.2; 68.0] to 60.2 [36.9; 82.8], p = .0427) and remained unchanged in the glimepiride group. CONCLUSIONS: Improving metabolic control has beneficial effects in microvascular function in type 2 diabetic patients. Treatment of type 2 diabetic patients with pioglitazone exerts additional effects on endothelial function beyond metabolic control.  相似文献   
90.
To study the interactions between the parasitic protozoan Giardia lamblia and its environment, we have cloned the gene that encodes the two major surface-labeled trophozoite protein species. Sequence analysis of this gene reveals a single open reading frame specifying a hydrophilic, cysteine-rich (11.8%) protein of 72.5-kDa molecular mass with an amino-terminal signal peptide and a postulated hydrophobic membrane-spanning anchor region near the carboxyl terminus. Most of the cysteine residues (58 of 84) are in the motif Cys-Xaa-Xaa-Cys, which is dispersed 29 times throughout the sequence. Antibodies against the recombinant protein react with the entire surface of live trophozoites, including flagella and adhesive disc. These antibodies inhibit trophozoite attachment, prevent growth, and immunoprecipitate the major approximately 66- and 85-kDa proteins from surface-labeled live trophozoites. The recombinant Escherichia coli also expresses polypeptides of approximately 66- and 85-kDa molecular mass, which are not fusion proteins. This suggests that the processing and/or conformational changes that lead to production of these two peptide species in E. coli reflect those that occur in Giardia. The abundance of cysteine residues suggests that the native proteins on the parasite surface may contain numerous disulfide bonds, which would promote resistance to intestinal fluid proteases and to the detergent activity of bile salts and would help to explain the survival of Giardia in the human small intestine.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号