全文获取类型
收费全文 | 3283篇 |
免费 | 236篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 104篇 |
妇产科学 | 72篇 |
基础医学 | 519篇 |
口腔科学 | 35篇 |
临床医学 | 357篇 |
内科学 | 720篇 |
皮肤病学 | 48篇 |
神经病学 | 310篇 |
特种医学 | 110篇 |
外科学 | 372篇 |
综合类 | 28篇 |
一般理论 | 4篇 |
预防医学 | 240篇 |
眼科学 | 78篇 |
药学 | 209篇 |
中国医学 | 12篇 |
肿瘤学 | 284篇 |
出版年
2024年 | 8篇 |
2023年 | 36篇 |
2022年 | 86篇 |
2021年 | 144篇 |
2020年 | 75篇 |
2019年 | 101篇 |
2018年 | 124篇 |
2017年 | 88篇 |
2016年 | 116篇 |
2015年 | 136篇 |
2014年 | 155篇 |
2013年 | 191篇 |
2012年 | 292篇 |
2011年 | 268篇 |
2010年 | 167篇 |
2009年 | 144篇 |
2008年 | 202篇 |
2007年 | 171篇 |
2006年 | 173篇 |
2005年 | 187篇 |
2004年 | 161篇 |
2003年 | 152篇 |
2002年 | 137篇 |
2001年 | 34篇 |
2000年 | 17篇 |
1999年 | 21篇 |
1998年 | 34篇 |
1997年 | 19篇 |
1996年 | 15篇 |
1995年 | 13篇 |
1994年 | 9篇 |
1993年 | 9篇 |
1992年 | 12篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 4篇 |
1974年 | 1篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1921年 | 1篇 |
1884年 | 1篇 |
1883年 | 1篇 |
排序方式: 共有3534条查询结果,搜索用时 0 毫秒
1.
2.
Maarten E Tushuizen Mathijs C Bunck Petra J Pouwels Jan Hein T van Waesberghe Michaela Diamant Robert J Heine 《Liver international》2006,26(8):1015-1017
BACKGROUND: Fat accumulation in the liver or non-alcoholic fatty liver disease (NAFLD) is regarded as a key pathogenic factor and component of the metabolic syndrome. It was reported that administration of the incretin mimetic exenatide reversed hepatic steatosis in an obese mouse model. We had the opportunity to study the effect of additional exenatide administration on liver fat content in a patient with type 2 diabetes. CASE REPORT: A 59-year-old male with poorly controlled type 2 diabetes was treated with exenatide in addition to metformin monotherapy. Following 44 weeks of exenatide therapy, mean the liver fat measured by liver spectroscopy declined from 15.8% to 4.3%. This dramatic decrease in liver fat was accompanied by significant beneficial changes in several cardiovascular disease risk factors and improvement of all liver enzymes, in particular alanine aminotransferase, the most important marker of liver steatosis. CONCLUSION: This case report suggests that the incretin mimetic exenatide decreases hepatic fat accumulation and may play a role in the future treatment of NAFLD, and the associated insulin resistance and cardiovascular risk factors in an ever-growing high-risk population. 相似文献
3.
Imaging of activated microglia with PET and [11C]PK 11195 in corticobasal degeneration. 总被引:3,自引:0,他引:3
Karsten Henkel Jochen Karitzky Michaela Schmid Irina Mader Gerhard Glatting Jürgen W Unger Bernd Neumaier Albert C Ludolph Sven N Reske G Bernhard Landwehrmeyer 《Movement disorders》2004,19(7):817-821
Positron emission tomography (PET) using [(11)C]PK 11195, a ligand for peripheral benzodiazepine receptor binding sites, offers the opportunity to image activated microglia in vivo. This tool may therefore be used to display the occurrence of microglial activation in the course of neurodegeneration. A patient with the clinical diagnosis of corticobasal degeneration (CBD) and left-sided symptoms was studied using fluorodeoxyglucose (FDG) and [(11)C]PK 11195 PET. We found a marked right hemispheric hypometabolism and asymmetric microglial activation in corresponding areas of the basal ganglia and right temporal and parietal cortex. [(11)C]PK 11195 PET suggests involvement of microglial activation in the pathogenesis of CBD. 相似文献
4.
Kurt Hannes Wollinsky Margret Oethinger Michaela Bü chele Patrick Kluger Wolfhart Puhl Hans-Hinrich Mehrkens 《Acta orthopaedica》1997,68(3):225-230
40 patients undergoing primary hip arthroplasty, given autologous processed blood transfusion, were randomized to receive no antibiotic prophylaxis (group A, n 20) or cefuroxime (1.5 g single injection; group B, n 20). Bacterial contamination at various steps in the autotransfusion procedure was assessed in liquid and solid culture media. the operation field and the wound drainage blood were never contaminated in either of the groups but some of the suction tips were. Parts of the Vacufix® blood collection bags of group A contained bacteria, but none in group B. Processed red blood cell concentrates in both groups showed bacterial growth. Greater blood loss did not increase the contamination rate in general. Isolated bacteria included the species Staphylococcus epidermidis, coagulase-negative staphylococci and Propionibacteria in both groups, but with different cell counts. in addition, Corynebacterium bovis et minutissimum and Moraxella were identified in group A.
In conclusion, autologous blood transfusion was a safe procedure. If contamination occurred, the bacterial count was low, and the bacteria of low pathogenicity. Antibiotic prophylaxis with cefuroxime reduced this contamination of suction tips and collection bags and limited the transfer of autologous blood products. 相似文献
In conclusion, autologous blood transfusion was a safe procedure. If contamination occurred, the bacterial count was low, and the bacteria of low pathogenicity. Antibiotic prophylaxis with cefuroxime reduced this contamination of suction tips and collection bags and limited the transfer of autologous blood products. 相似文献
5.
Tomáš Šimůnek Martin Štěrba Olga Popelová Michaela Adamcová Radomír Hrdina Vladimír Geršl 《Pharmacological reports : PR》2009,61(1):154-171
The risk of cardiotoxicity is the most serious drawback to the clinical usefulness of anthracycline antineoplastic antibiotics, which include doxorubicin (adriamycin), daunorubicin or epirubicin. Nevertheless, these compounds remain among the most widely used anticancer drugs. The molecular pathogenesis of anthracycline cardiotoxicity remains highly controversial, although the oxidative stress-based hypothesis involving intramyocardial production of reactive oxygen species (ROS) has gained the widest acceptance. Anthracyclines may promote the formation of ROS through redox cycling of their aglycones as well as their anthracycline-iron complexes. This proposed mechanism has become particularly popular in light of the high cardioprotective efficacy of dexrazoxane (ICRF-187). The mechanism of action of this drug has been attributed to its hydrolytic transformation into the iron-chelating metabolite ADR-925, which may act by displacing iron from anthracycline-iron complexes or by chelating free or loosely bound cellular iron, thus preventing site-specific iron-catalyzed ROS damage. However, during the last decade, calls for the critical reassessment of this “ROS and iron” hypothesis have emerged. Numerous antioxidants, although efficient in cellular or acute animal experiments, have failed to alleviate anthracycline cardiotoxicity in clinically relevant chronic animal models or clinical trials. In addition, studies with chelators that are stronger and more selective for iron than ADR-925 have also yielded negative or, at best, mixed outcomes. Hence, several lines of evidence suggest that mechanisms other than the traditionally emphasized “ROS and iron” hypothesis are involved in anthracycline-induced cardiotoxicity and that these alternative mechanisms may be better bases for designing approaches to achieve efficient and safe cardioprotection. 相似文献
6.
7.
Activation of influenza A viruses by trypsin treatment. 总被引:86,自引:0,他引:86
A comparative analysis has been carried out on the infectivity of virus of several influenza A strains grown in different host systems. Strains A/swine/Shope/31 (Hsw1N1), A/PR/8/34 (HON1), A/FM/1 (H1N1), A/Singapore/1/57 (H2N2), A/equine/Miami/1/63 (Heq2Neq2), and A/chick/Germany/49 (Hav2Neq1) exhibit host-dependent differences in infectivity. Virions grown in embryonated eggs and cultures of chorioallantoic membrane cells are highly infectious, whereas virions grown in cultures of chick embryo cells have a low infectivity that significantly increases after treatment in vitro with trypsin. In contrast, fowl plague viruses do not show host-dependent variations in infectivity. Virions grown in all host systems tested are highly infectious, and the infectivity of virions grown in chick embryo cells cannot be enhanced by trypsin treatment.The activation of virus particles appears to be based on the cleavage of hemagglutinin glycoprotein HA. This concept is supported by the following observations: (i) In virions of low infectivity only uncleaved glycoprotein HA can be detected. Virions of high infectivity exhibit complete or at least partial cleavage of the hemagglutinin. (ii) The activation of virions by trypsin treatment is always paralleled by cleavage of HA. (iii) Cleavage of HA is the only effect which can be detected after trypsin treatment. The neuraminidase is neither inactivated nor removed from the virion. (iv) Studies on recombinants of virus N and fowl plague virus (Rostock) show that host-dependent variation of infectivity and activation by trypsin, features specific for parent virus N, are found only with recombinant N(H)-FPV/Ro(N) but not with recombinant FPV/Ro(H)-N(N).Efficient plaque formation and serial passages are possible only if highly infectious particles are formed in a given host system. Thus, all strains analyzed undergo, in the absence of trypsin, successive growth cycles in eggs and chorioallantoic membrane cells and form plaques in chorioallantoic membrane cells. In contrast, in chick embryo cells only viruses containing the fowl plague virus hemagglutinin produce plaques and replicate under multiple cycle conditions without the addition of trypsin.The data show that cleavage of HA is not a precondition for virus assembly and hemagglutinating activity, but that it is necessary for infectivity. These findings are compatible with the hypothesis that, in addition to its role in adsorption, the hemagglutinin has another function in the infection process and cleavage is required for this function. 相似文献
8.
Kevin P Weinfurt Michaela A Dinan Jennifer S Allsbrook Jo?lle Y Friedman Mark A Hall Kevin A Schulman Jeremy Sugarman 《Academic medicine》2006,81(2):113-118
PURPOSE: To document the current state of institutional review board (IRB) and conflict of interest committee policies regarding disclosures of financial conflicts of interest to potential research participants, and to use this information to identify and share models for effectively achieving disclosure. METHOD: The authors identified the 123 U.S. academic medical centers that have IRBs and sought their IRB and institutional policies regarding financial conflicts of interest. In February and March 2004, using manual and key word searches, each institution's Web site was searched to identify documents containing information regarding the disclosure of financial conflicts of interest. Letters were sent to 24 institutions that had either no information or incomplete information posted on their Web sites. To assess institutions' guidelines for disclosure, the authors extracted and content coded each institution's information on disclosure. RESULTS: Relevant information was obtained from 120 (98%) academic medical centers (AMCs), of which 57 (48%) mentioned disclosing financial conflicts to potential research participants. Of these 57, 33 (58%) included verbatim language that could be used in informed consent documents. AMCs' recommendations and requirements for disclosure included details of the financial arrangement, administrative management of conflicts of interest, and encouragement of dialogue between the investigator and the potential research participant. CONCLUSIONS: Considerable variability exists concerning the specific information that should be disclosed. Most of the AMCs' policies were consistent with the goal of protection from legal liability. Significant questions remain, however, concerning the goals of disclosure and the most effective methods for achieving those goals. 相似文献
9.
Libra M Capello D Gloghini A Laura P Berra E Cerri M Gasparotto D Franca S De Re V Gaidano G Carbone A 《The Journal of pathology》2005,206(1):87-91
Hepatitis C virus (HCV) and aberrant somatic hypermutation (SHM) have each been suggested to contribute to the development of B-cell non-Hodgkin's lymphoma (NHL). The incidence of PIM-1, PAX-5, RhoH/TTF, and c-MYC mutations in tumour biopsy specimens from 32 HCV-infected B-cell NHL patients was analysed to determine whether the extent of aberrant SHM among these patients differed from that previously reported for HCV-negative B-cell NHL patients. Mutation of PIM-1, PAX-5, RhoH/TTF, and c-MYC was detected in 4 (13%), 5 (16%), 4 (13%), and 4 (13%) of 32 samples, respectively. In HCV-positive B-cell NHL patients, the frequency of aberrant SHM was lower than that already found in HCV-negative B-cell NHL patients. This indicates that, unlike B-cell lymphomas from HCV-negative patients, aberrant SHM may not contribute significantly to malignant transformation in HCV-associated B-cell lymphomas. 相似文献
10.
Anca Ram Qiuhe Cao Paul E. Keck Harrison G. Pope Koichi Otani Gerard Addonizio Susan L. McElroy Sunao Kaneko Michaela Redlichova Elliot S. Gershon Pablo V. Gejman 《American journal of medical genetics. Part A》1995,60(3):228-230
Dysfunction of the dopaminergic system has been suggested as a pathogenic mechanism in neuroleptic malignant syndrome. Therefore, we examined the complete coding sequences of the dopamine D2 receptor (DRD2) gene for structural abnormalities in 12 patients with a history of NMS, including two cases of familial NMS. Mutational analysis was performed by denaturing gradient gel electrophoresis (DGGE), a highly sensitive technique for detecting sequence differences. We found in one patient with a history of NMS a nucleotide substitution at codon 310 (CCG→TCG) of exon 7 of the DRD2 gene which predicts the replacement of proline to serine in the third cytoplasmic loop of the receptor, a part of the receptor that interacts with G-proteins. A larger series of patients with NMS needs to be investigated to establish whether this allele is associated with an increased susceptibility to NMS. © 1995 Wiley-Liss, Inc. 相似文献