全文获取类型
收费全文 | 18594篇 |
免费 | 3288篇 |
国内免费 | 265篇 |
专业分类
耳鼻咽喉 | 716篇 |
儿科学 | 572篇 |
妇产科学 | 433篇 |
基础医学 | 1297篇 |
口腔科学 | 539篇 |
临床医学 | 2529篇 |
内科学 | 4204篇 |
皮肤病学 | 631篇 |
神经病学 | 1892篇 |
特种医学 | 691篇 |
外科学 | 3960篇 |
综合类 | 169篇 |
现状与发展 | 2篇 |
一般理论 | 6篇 |
预防医学 | 1706篇 |
眼科学 | 505篇 |
药学 | 665篇 |
2篇 | |
中国医学 | 38篇 |
肿瘤学 | 1590篇 |
出版年
2024年 | 107篇 |
2023年 | 611篇 |
2022年 | 303篇 |
2021年 | 630篇 |
2020年 | 935篇 |
2019年 | 466篇 |
2018年 | 940篇 |
2017年 | 837篇 |
2016年 | 953篇 |
2015年 | 895篇 |
2014年 | 1225篇 |
2013年 | 1461篇 |
2012年 | 916篇 |
2011年 | 824篇 |
2010年 | 948篇 |
2009年 | 1130篇 |
2008年 | 756篇 |
2007年 | 678篇 |
2006年 | 676篇 |
2005年 | 538篇 |
2004年 | 492篇 |
2003年 | 437篇 |
2002年 | 390篇 |
2001年 | 268篇 |
2000年 | 186篇 |
1999年 | 257篇 |
1998年 | 308篇 |
1997年 | 328篇 |
1996年 | 362篇 |
1995年 | 317篇 |
1994年 | 219篇 |
1993年 | 167篇 |
1992年 | 194篇 |
1991年 | 198篇 |
1990年 | 130篇 |
1989年 | 179篇 |
1988年 | 154篇 |
1987年 | 140篇 |
1986年 | 134篇 |
1985年 | 132篇 |
1984年 | 122篇 |
1983年 | 121篇 |
1982年 | 101篇 |
1981年 | 71篇 |
1980年 | 78篇 |
1979年 | 56篇 |
1978年 | 69篇 |
1977年 | 63篇 |
1976年 | 57篇 |
1975年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Human Aldehyde Dehydrogenase: Kinetic Identification of the Isozyme for Which Biogenic Aldehydes and Acetaldehyde Compete 总被引:1,自引:0,他引:1
Alexander D. MacKerell Jr PhD Erich E. Blatter BS Regina Pietruszko PhD 《Alcoholism, clinical and experimental research》1986,10(3):266-270
Michaelis constants and maximal velocities for phenylacetaldehyde (a metabolite of phenylethylamine), 3,4-dihydroxyphenylacetaldehyde (a metabolite of dopamine), 5-hydroxyindole acetaldehyde (a metabolite of serotonin), and 3,4-dihydroxyphenylglycolaldehyde (a metabolite of epinephrine and norepinephrine) have been determined for both cytoplasmic (E1) and mitochondrial (E2) isozymes of human liver aldehyde dehydrogenase (EC 1.2.1.3). Kinetic constants with biogenic aldehydes have never been previously determined for individual homogeneous isozymes of aldehyde dehydrogenase from any species. Mathematical treatment of these constants suggests that competition with acetaldehyde during alcohol metabolism would severely inhibit dehydrogenation of biogenic aldehydes with the mitochondrial and not the cytoplasmic isozyme of human liver aldehyde dehydrogenase. 相似文献
92.
Teng-Nan Lin BS Albert Y. Sun PhD Grace Y. Sun PhD 《Alcoholism, clinical and experimental research》1988,12(6):795-800
In the presence of ATP, MgCl2, and CoASH, somal plasma membranes isolated from rat cerebral cortex were active in transferring arachidonic acid to phosphatidylinositols, phosphatidylcholines, and triacylglycerols. Ethanol (350-525 mM) added to the incubation mixture inhibited arachidonic acid incorporation into phospholipids, while it enhanced the incorporation into triacylglycerols. Under these conditions, ethanol was found to react with arachidonic acid to form arachidonoyl ethyl ester. The incorporation of labeled arachidonic acid into glycerolipids as well as the synthesis of ethyl esters required the presence of ATP and CoASH for maximal activity. Nevertheless, each uptake process exhibited a unique pH profile. The esterification of arachidonic acid was not specific for ethanol as other aliphatic alcohols (e.g., propanol and butanol) were also able to react with labeled arachidonic acid to form the respective esters. Somal plasma membranes isolated from mice after chronic ethanol administration showed an increase in arachidonoyl transfer to both phospholipids and triacylglycerols. When these membranes were challenged with ethanol (325 mM), those isolated from the chronic ethanol group showed a greater increase in the labeling of triacylglycerols and ethyl esters than those from controls. Thus, different acyltransferases exhibite different responses to the effects of ethanol in vitro and in vivo. 相似文献
93.
Actinobacillus actinomycetemcomitans, a fastidious gram-negative bacillus, has been reported as the cause of prosthetic valve endocarditis in 11 patients. Two additional patients are reported and the literature is reviewed. All cases occurred greater than 1 year after implantation of the prosthesis. Six of the 13 patients had had recent dental work or had poor dentition. Three patients had received endocarditis prophylaxis. Ten of 13 were cured with antibiotics alone. Only one patient suffered from congestive heart failure, and only one had documented evidence of major systemic emboli during antimicrobial therapy. Valve replacement was necessary in only two during antimicrobial therapy. A actinomycetemcomitans should be considered as a possible etiologic agent in late prosthetic valve endocarditis, particularly when blood cultures are initially negative. A regimen of a beta-lactam antibiotic in combination with an aminoglycoside is recommended for 4-6 weeks. The excellent in vitro activity of the third-generation cephalosporins and rifampin promise new therapeutic options. 相似文献
94.
Paul J. Kulkosky PhD Gordon W. Glazner BS 《Alcoholism, clinical and experimental research》1988,12(2):277-281
Cholecystokinin (CCK) and bombesin (BBS) are neuropeptides of the brain and gut which have been shown to inhibit intake of ethanol. CCK octapeptide and BBS tetradecapeptide were injected intraperitoneally in both single doses and combinations of doses to determine interactions of the two peptides in the control of consumption of ethanol. Water-deprived rats were given access to 5% w/v ethanol for 30 min, followed by a 30-min access to water, daily. One minute before presentation of ethanol, rats were injected with either saline or one of ten peptide solutions (three of CCK alone, three of BBS alone, and four combinations of both). Results from the injections of single peptides were used to determine predicted inhibitions of the peptide combinations, assuming perfect additivity of doses. None of the actual values of inhibition of intake of ethanol by peptide combinations differed significantly from its predicted additive value. Endogenous CCK-like and BBS-like peptides may suppress intake of ethanol by an additive mechanism of inhibition. 相似文献
95.
Patellar instability after total knee arthroplasty 总被引:4,自引:0,他引:4
Twenty-five knees with symptomatic lateral patellar instability after total knee arthroplasty (TKA) were treated by operative realignment. Causes of instability include errors in surgical technique, quadriceps imbalance, and trauma. Fourteen knees had proximal realignment, nine had combined proximal and distal realignment, and two had component revision. At an average follow-up period of 50 months, 20 knees had normal patellar tracking and five had recurrent instability. Two patellar tendon ruptures occurred after combined realignment. Proximal realignment alone, in the absence of component malposition, is recommended for the management of patellar instability. Component malposition should be corrected by component revision. Combined proximal and distal realignment procedures are recommended only with great caution because of the predisposition to serious complications such as patellar tendon rupture. 相似文献
96.
97.
98.
99.
LEE JS IM HH JUNG Y JUNG IS JANG JY CHUN YK CHO YD KIM JO CHO JY KIM YS SHIM CS & KIM BS 《Neurogastroenterology and motility》2006,18(6):493-494
Background: Recent development of extracorporeal magnetic stimulation (ECMS) which uses current‐changing magnetic fields allows the induction of electrical stimulation in the desired deep tissue. Recent study showed the sacral nerve stimulation reduces corticoanal excitability that may play a functional role in anal continence mechanisms. Preliminary study shows that ECMS of sacral nerve can modify pelvic floor function and expel rectal balloon in patients with pelvic floor dyssynergia (PFD). Aims: To evaluate the effect of ECMS compared with biofeedback therapy (BF) in patients with PFD. Methods and Materials: Thirty‐eight patients who fulfilled Rome II criteria for PFD by colon transit time and anorectal function tests, were randomly treated with 8 sessions of ECMS (2/weeks; n = 19) at prone position or BF (2/weeks; n = 19) at sitting position. Stimulation parameters were set at 50–80% of maximum intensity, 10 and 50 Hz frequency, 3 s burst length with 3 and 6 s off using arm‐typed stimulator (BioCom‐1000, Mcube Co., Korea). Symptom scores for constipation with/without anorectal function test were repeatedly measured after each treatment. Response was defined as 50% or more decreased symptom score after treatment (partial response: 30–50%, poor: <30%). Results: Fifteen patients (age 49.1 ± 13.4 years, mean ± SD; 4 men) completed 8 session of BF and 14 patients (54.5 ± 17.6 years, 3 men) completed 8 session of ECMS. Four patients of BF group discontinued treatment due to unsatisfactory therapeutic effect (n = 1) and withdrew consent (n = 3) and 5 patients of ECMS group discontinued treatment because of same reasons (n = 1, 4). Total symptom scores were significantly decreased after treatment of 8 session in both treatment groups (13.4 ± 6.6 vs. 4.3 ± 4.0 for BF, p = 0.009; 14.9 ± 5.6 vs. 3.4 ± 4.0 for ECMS, p < 0.001). Bowel movements per week were also significantly increased after treatment in both groups (median 2 vs. 7 for BF, p = 0.035; median 2 vs. 7 for ECMS, p = 0.008). Thirteen out of 15 patients showed response in BF group and 12 out of 14 showed good response in ECMS group. No adverse effects in both groups. Conclusions: ECMS is as effective as BF for the treatment of PFD. Long‐term effect of ECMS for the patients with pelvic floor dyssynergia need to be evaluated in the near future. 相似文献
100.