全文获取类型
收费全文 | 23187篇 |
免费 | 1740篇 |
国内免费 | 42篇 |
专业分类
耳鼻咽喉 | 173篇 |
儿科学 | 784篇 |
妇产科学 | 625篇 |
基础医学 | 3046篇 |
口腔科学 | 244篇 |
临床医学 | 2951篇 |
内科学 | 4297篇 |
皮肤病学 | 283篇 |
神经病学 | 2266篇 |
特种医学 | 444篇 |
外科学 | 2410篇 |
综合类 | 381篇 |
一般理论 | 81篇 |
预防医学 | 3468篇 |
眼科学 | 248篇 |
药学 | 1314篇 |
中国医学 | 18篇 |
肿瘤学 | 1936篇 |
出版年
2024年 | 42篇 |
2023年 | 303篇 |
2022年 | 468篇 |
2021年 | 976篇 |
2020年 | 614篇 |
2019年 | 931篇 |
2018年 | 941篇 |
2017年 | 704篇 |
2016年 | 753篇 |
2015年 | 775篇 |
2014年 | 1013篇 |
2013年 | 1378篇 |
2012年 | 2094篇 |
2011年 | 2036篇 |
2010年 | 1070篇 |
2009年 | 864篇 |
2008年 | 1508篇 |
2007年 | 1429篇 |
2006年 | 1429篇 |
2005年 | 1296篇 |
2004年 | 1117篇 |
2003年 | 932篇 |
2002年 | 822篇 |
2001年 | 135篇 |
2000年 | 141篇 |
1999年 | 141篇 |
1998年 | 180篇 |
1997年 | 101篇 |
1996年 | 74篇 |
1995年 | 66篇 |
1994年 | 47篇 |
1993年 | 52篇 |
1992年 | 41篇 |
1991年 | 31篇 |
1990年 | 44篇 |
1989年 | 26篇 |
1988年 | 28篇 |
1987年 | 24篇 |
1986年 | 22篇 |
1985年 | 30篇 |
1984年 | 35篇 |
1983年 | 26篇 |
1982年 | 29篇 |
1981年 | 39篇 |
1980年 | 18篇 |
1979年 | 15篇 |
1978年 | 14篇 |
1977年 | 11篇 |
1975年 | 8篇 |
1940年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Rajiv Jalan Rebecca Gooday Ronan E. O'Carroll Doris N. Redhead Robert A. Elton Peter C. Hayes 《Journal of hepatology》1995,23(6)
Background/Aims: This study was designed to assess changes in: (a) neuropsychological tests, measures of memory, quality of life and scores for anxiety and depression; (b) liver function tests; and (c) the relationship between these following transjugular intrahepatic portosystemic stent-shunt.Methods: Twenty-nine patients undergoing transjugular intrahepatic portosystemic stent-shunt for recurrent variceal haemorrhage, 12 matched patients with cirrhosis and variceal haemorrhage manage with variceal band ligation and 16 normal controls were studied. Patients in any of the groups who were clinically encephalopathic were excluded from the study. Serial changes in the conventional liver function tests and Indocyanine green clearance, and psychometric function (Hospital Anxiety Depression Scale, Rivermead Behavioral Memory Test, Quality of Life and the memory and reaction sub-tests of the Cambridge Automated Neuropsychological Test Assessment Battery) were measured prior to and 1, 3, 9 and 15 months following transjugular intrahepatic portosystemic stent-shunt.Results: Over a mean follow up of 9.1 months in the transjugular intrahepatic portosystemic stent-shunt group (range 3–28), one patient (3%) developed clinically detectable encephalopathy. Sixty-seven percent of patients with cirrhosis showed evidence of subclinical encephalopathy as compared with the control population. Significant deterioration occurred in the reaction sub-tests of the Cambridge Automated neuropsychological Test Assessment Battery in patients, both in the transjugular intrahepatic portosystemic stent-shunt group and the controls with cirrhosis, during follow up. Transjugular intrahepatic portosystemic stent-shunt was followed by significant deterioration in levels of anxiety and psychological component of the quality of life. The Rivermead Behavioural Memory Test and the memory sub-test of the Cambridge Automated Neurpsychological Test Assessment Battery did, however, improve significantly at 1 and 15 months after transjugular intrahepatic portosystemic stent-shunt, respectively. Serum alanine aminotransferase, bilirubin and indocyanine green clearance deteriorated significantly following transjugular intrahepatic portosystemic stent-shunt (p<0.001, p<0.001 and p<0.0001, respectively). Significant correlation was observed between changes in the indocyanine green clearance and changes in the complex and simple reaction time subtests of the Cambridge Automated Neuropsychological Test Assessment Battery (r=0.6 and r=0.66, respectively).Conclusions: The results of this study showed that about 67% of patients with cirrhosis were subclinically encephalopathic and that temporary deterioration occurred in the Cambridge Automated Neuropsychological Test Assessment Battery during follow up, both in patients having transjugular intrahepatic portosystemic stent-shunt and in the controls with cirrhosis. These parallel the changes in the liver function tests and indocyanine green clearance. Temporary deterioration was also observed in the Quality of Life and Hospital Anxiety Depression Scale in the transjugular intrahepatic portosystemic stent-shunt group, although the measures of memory improved. Further studies should address the biochemical mechanisms of these changes and the role of prophylactic measures. 相似文献
12.
The anucleate (distal) segment of a crayfish medial giant axon (MGA) remains intact for months in vivo after severing the axon from its cell body, a phenomenon referred to as long-term survival (LTS). We collected axoplasm from chronic anucleate MGAs by perfusing 2-cm lengths of axons with an intracellular saline. This axoperfusate was analyzed by SDS-PAGE and silver stained. Axoperfusate proteins from intact MGAs and from chronic anucleate MGAs exhibiting LTS for up to 6 months were the same. Furthermore, immunoreactive levels of actin and β-tubulin were similar in axoperfusates from intact and chronic anucleate MGAs. This maintenance of proteins in chronic anucleate MGAs must be due to a lack of protein degradation and/or to local protein synthesis by a source other than the cell body. To investigate local protein synthesis in vitro, we added [35S]-methionine to the extracellular saline surrounding intact and chronic anucleate MGAs. After 4- to 6-h incubations, radiolabelled proteins were detected in axoperfusates analyzed by SDS-PAGE and fluorography. The similarity between radiolabelled proteins in axoperfusates and MGA glial sheaths indicated a glial origin for the radiolabelled axoperfusate proteins. Various observations and control experiments suggested that glial-axonal protein transfer occurred by a physiological process. Glial-axonal protein transfer may contribute to the maintenance of proteins during LTS of chronic anucleate MGAs. 相似文献
13.
Mark A. Beilke Debra Riding In Rebecca Hamilton Gary A. Stone Elaine K. Jordan Gene Brashears Wayne Nusbaum David Huddleston Clarence J. Gibbs Jr. Maneth Gravell 《Journal of neuroimmunology》1991,33(2):129-143
HLA-DR expression in neuroendothelial cells (NEC) was studied during the course of SIV encephalitis in rhesus monkeys. HLA-DR determinants were detected on NEC in monkeys with SIV encephalitis, but not in control animals. In situ hybridization with an SIV probe indicated that HLA-DR expression was not a consequence of SIV replication within NEC. Cultured rhesus NEC stimulated with gamma interferon expressed HLA-DR to a higher degree than cultured brain fibroblasts or astrocytes. These data support the contention that NEC participate in retrovirus-induced inflammation and autoimmunity within the central nervous system. 相似文献
14.
Jisun Oh Matthew R Ban Brooke A Miskie Rebecca L Pollex Robert A Hegele 《Lipids in health and disease》2007,6(1):7
Background
Statin-related skeletal muscle disorders range from benign myalgias – such as non-specific muscle aches or joint pains without elevated serum creatinine kinase (CK) concentration – to true myositis with >10-fold elevation of serum CK, to rhabdomyolysis and myoglobinuria. The genetic basis of statin-related muscle disorders is largely unknown. Because mutations in the COQ2 gene are associated with severe inherited myopathy, we hypothesized that common, mild genetic variation in COQ2 would be associated with inter-individual variation in statin intolerance. We studied 133 subjects who developed myopathy on statin monotherapy and 158 matched controls who tolerated statins without incident or complaint. 相似文献15.
Rebecca Suckling Mohamed Morsy Eric S Chemla 《Nephrology, dialysis, transplantation》2007,22(3):970-971
Sir, The expansion of haemodialysis includes older patients withcomorbidities, poor quality vessels, unsuitable for transplantationor peritoneal dialysis. Vascular access complications accountfor 20% of hospital admissions [1]. With exhausted sites inupper extremities, unusual sites for arteriovenous grafts formationare used [2]. The 相似文献
16.
17.
Siddharth K. Prakash Soniely Lugo‐Ruiz Michelle Rivera‐Dávila Nunilo Rubio Jr. Avni N. Shah Rebecca C. Knickmeyer Cindy Scurlock Melissa Crenshaw Shanlee M. Davis Gary A. Lorigan Aaron T. Dorfman Karen Rubin Cheryl Maslen Vaneeta Bamba Paul Kruszka Michael Silberbach Scientific Advisory Board of the TSRR 《American journal of medical genetics. Part C, Seminars in medical genetics》2019,181(1):7-12
To address knowledge gaps about Turner syndrome (TS) associated disease mechanisms, the Turner Syndrome Society of the United States created the Turner Syndrome Research Registry (TSRR), a patient‐powered registry for girls and women with TS. More than 600 participants, parents or guardians completed a 33‐item foundational survey that included questions about demographics, medical conditions, psychological conditions, sexuality, hormonal therapy, patient and provider knowledge about TS, and patient satisfaction. The TSRR platform is engineered to allow individuals living with rare conditions and investigators to work side‐by‐side. The purpose of this article is to introduce the concept, architecture, and currently available content of the TSRR, in anticipation of inviting proposals to utilize registry resources. 相似文献
18.
Myakov A Nieman L Wicky L Utzinger U Richards-Kortum R Sokolov K 《Journal of biomedical optics》2002,7(3):388-397
We present the design and construction of a fiber optic probe for elastic light scattering spectroscopy in vivo with polarized excitation and polarization sensitive detection. The performance of the fiber probe is evaluated using a suspension of polystyrene spheres placed atop a diffusely scattering substrate, and it demonstrates that the size-dependent characteristics of the scatterers can be extracted in the presence of a highly diffusely scattering background using a linear combination of forward and backward Mie scattering components of the scatterers. Subsequently, Mie theory calculations are performed over a broad range of diagnostically relevant parameters of nuclei-mean diameter, size distribution, and relative refractive index-to understand how the polarized reflectance measurements with the fiber probe can be used to extract morphological information about epithelial tissue. Finally, the feasibility of in vivo measurements with the fiber optic based polarization sensitive light scattering spectroscopy is demonstrated. 相似文献
19.
Cloning and expression of the major secreted cathepsin B-like protein from juvenile Fasciola hepatica and analysis of immunogenicity following liver fluke infection 下载免费PDF全文
Law RH Smooker PM Irving JA Piedrafita D Ponting R Kennedy NJ Whisstock JC Pike RN Spithill TW 《Infection and immunity》2003,71(12):6921-6932
The functions of the cathepsin B-like proteases in liver flukes are unknown and analysis has been hindered by a lack of protein for study, since the protein is produced in small amounts by juvenile flukes. To circumvent this, we isolated and characterized a cDNA encoding the major secreted cathepsin B from Fasciola hepatica. The predicted preproprotein is 339 amino acids in length, with the mature protease predicted to be 254 amino acids long, and shows significant similarity to parasite and mammalian cathepsin B. Only one of the two conserved histidine residues required for cathepsin B exopeptidase activity is predicted to be present. Recombinant preproprotein was produced in yeast, and it was shown that the recombinant proprotein can undergo a degree of self-processing in vitro to the mature form, which is active against gelatin and synthetic peptide substrates. The recombinant protein is antigenic in vaccinated rats, and antibodies to the protein are detected early after infection of rats and sheep with F. hepatica. The kinetics of the response to cathepsin B and cathepsin L after infection of sheep and rats confirm the temporal expression of these proteins during the life cycle of the parasite. 相似文献
20.
BACKGROUND: Emergency admission rates have been rising steadily in recent years, with the majority of the increase owing to emergency medical admissions. Possible causative factors include changing demography, incidence of disease, admission thresholds, multiple admissions, and appropriateness of admission. AIM: To investigate the impact of patient and practice factors on variance in general practices' emergency medical admissions rates. DESIGN OF STUDY: Multiple regression analysis relating emergency medical admission rates of general practices to patient and practice characteristics. SETTING: The study was conducted between 1996 and 1997 in the acute hospital trust serving the study area, Dundee, Scotland. METHOD: Scottish Morbidity Record 1 (SMR1) data, which contains details of all hospital consultant episodes, was used to calculate individual practices emergency medical admission rates. These rates were then standardised to an expected value of 100. Forward selection was used to find a suitable multiple regression model to predict each practice's emergency medical admission rate from practice and patient variables. RESULTS: Crude emergency medical admission rates for general practices showed a 1.8-fold variation between the top and bottom deciles. The deprivation status and age of patients explained 42% of the variance in admission rates (64% with the exclusion of one practice that had a poor fit to the model). After correcting for age and deprivation there was a 1.2-fold variation in general practices' emergency medical admission rates. CONCLUSION: The most important factors in explaining variance in general practices' emergency medical admission rates are socio-demographic, with age and deprivation explaining a large proportion of the variation. We found no evidence to support the contention that general practice factors were linked with admission rates. 相似文献