全文获取类型
收费全文 | 6356篇 |
免费 | 438篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 346篇 |
妇产科学 | 60篇 |
基础医学 | 650篇 |
口腔科学 | 147篇 |
临床医学 | 772篇 |
内科学 | 1300篇 |
皮肤病学 | 63篇 |
神经病学 | 627篇 |
特种医学 | 729篇 |
外科学 | 580篇 |
综合类 | 87篇 |
一般理论 | 3篇 |
预防医学 | 557篇 |
眼科学 | 265篇 |
药学 | 358篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 253篇 |
出版年
2021年 | 74篇 |
2020年 | 47篇 |
2019年 | 64篇 |
2018年 | 95篇 |
2017年 | 63篇 |
2016年 | 94篇 |
2015年 | 78篇 |
2014年 | 100篇 |
2013年 | 159篇 |
2012年 | 179篇 |
2011年 | 193篇 |
2010年 | 164篇 |
2009年 | 175篇 |
2008年 | 210篇 |
2007年 | 225篇 |
2006年 | 226篇 |
2005年 | 203篇 |
2004年 | 216篇 |
2003年 | 192篇 |
2002年 | 188篇 |
2001年 | 180篇 |
2000年 | 177篇 |
1999年 | 156篇 |
1998年 | 149篇 |
1997年 | 150篇 |
1996年 | 160篇 |
1995年 | 113篇 |
1994年 | 117篇 |
1993年 | 128篇 |
1992年 | 128篇 |
1991年 | 130篇 |
1990年 | 142篇 |
1989年 | 170篇 |
1988年 | 159篇 |
1987年 | 157篇 |
1986年 | 183篇 |
1985年 | 158篇 |
1984年 | 100篇 |
1983年 | 104篇 |
1982年 | 80篇 |
1981年 | 86篇 |
1980年 | 72篇 |
1979年 | 103篇 |
1978年 | 84篇 |
1977年 | 83篇 |
1976年 | 68篇 |
1975年 | 52篇 |
1974年 | 55篇 |
1973年 | 52篇 |
1970年 | 44篇 |
排序方式: 共有6822条查询结果,搜索用时 31 毫秒
41.
Current perspectives on septic shock 总被引:6,自引:0,他引:6
Although septic shock may be initiated by invading microbes, it is the metabolic and immunologic host responses that determine the true pathophysiology of this common critical care illness. Currently, septic shock therapeutics emphasize empiric and symptomatic treatment. Biochemical elucidation of the septic process will ultimately result in specific interventions for this ominous intensive care syndrome. 相似文献
42.
43.
44.
45.
The cytologic diagnosis of malignancy is frequently straightforward. For difficult cases, multiple immunostains and immunostain panels have been investigated without consensus. beta-human chorionic gonadotropin (hCG) has been reportedly expressed in malignancies, but not in normal tissue. HCG also has been reported as a specific marker of metastases in serous fluids when detected with laboratory assays. We investigated the clinical utility of hCG in this cytologic setting. A total of 97 cases of benign and malignant effusions were studied. Each case was immunostained with monoclonal hCG using the avidin-biotin technique and diaminobenzidine as a chromogen. Additionally, a mucicarmine stain was performed on most cases. Cases were evaluated for hCG expression and mucin in a blinded fashion. After the cases were reviewed, the diagnoses were unblinded and staining patterns were evaluated. Of the 47 benign cases studied, 23 (49%) exhibited immunoreactivity to hCG in at least 5% of mesothelial cells present. In contrast, 28 of 44 (64%) adenocarcionomas exhibited a similar degree of immunostaining. In all, 21 (48%) of the adenocarcinomas were also positive for mucin; five of these mucin-positive cases were negative for hCG. The combination of mucin and hCG detected 33 of 44 (75%) adenocarcinomas. We conclude that hCG lacks the specificity for malignant cells to be of clinical use in effusion cytology. 相似文献
46.
A comprehensive anatomic and radiographic analysis of the peribursal fat plane in 12 cadavers confirmed that the fat plane seen on radiographs represents extrasynovial fat lining the subacromial bursa and documented the anatomic relations of the bursa. A three-part retrospective clinical evaluation of rotator cuff tears, calcific tendinitis, and rheumatoid arthritis was performed. Two osteoradiologists blindly graded the appearance of the peribursal fat plane with the shoulder in external versus internal rotation in 21 patients with arthrographically intact rotator cuffs and 21 patients with disrupted rotator cuffs. The peribursal fat plane was seen better with disrupted rotator cuffs. The peribursal fat plane was seen better with the shoulder in internal rotation and was seen in 60% of control subjects but only 21% of patients with rotator cuff tears. Partial or complete obliteration of this fat plane is a sensitive (79%) but less specific (60%) indicator of rotator cuff tears. Obliteration of the peribursal fat plane by inflammatory processes in adjacent tissues, including calcific tendinitis and rheumatoid arthritis, occurred with a high frequency. 相似文献
47.
Rosenberg ZS; Jahss MH; Noto AM; Shereff MJ; Cheung Y; Frey CC; Norman A 《Radiology》1988,167(2):489-493
Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture. 相似文献
48.
J J Zimmerman 《Critical care medicine》1986,14(9):761-767
Inhibition by prostaglandin E1 (PGE1) of superoxide anion (O2-.) production by isolated intact human neutrophils (PMNs) was investigated utilizing initial-velocity enzyme kinetics. Lag time, linearity, rate, and extent of reaction were simultaneously examined. Dose-response data indicate progressive PGE1-induced suppression of O2-. synthesis by activated PMNs with a Ki value of 0.50 and 0.98 mumol/L for initial velocity and extent of reaction, respectively. There were no significant dose-related trends for either lag time or linearity for reactions with PGE1 concentrations less than 10(-6) mol/L; however, at concentrations of 10(-8) mol/L and greater, the length of reaction was progressively shortened. PGE1 inhibition of PMN-induced O2-. production does not involve PMN activation/desensitization since PGE1 itself cannot stimulate O2-. generation. Moreover, PGE1 does not function as a free-radical scavenger. These data indicate the clinical feasibility of utilizing PGE1 to titrate PMN-induced synthesis of active oxygen metabolites, in order to attenuate PMN-associated host autoinjury. 相似文献
49.
The three most widely used diagnostic systems in American psychiatry--the Feighner criteria, the Research Diagnostic Criteria, and DSM-III--appeared sequentially at 4-year intervals. The fact that the latter two systems each incorporated changes in essentially all diagnostic categories implied progress toward greater validity; however, this assumption has rarely been tested directly. To do this, the authors applied each of these three systems to 98 consecutively admitted patients with nonmanic psychoses. Although family history and 6-month follow-up data strongly supported the validity of diagnostic distinctions made in each of the three systems, they did not show increments in validity with successively developed criteria sets. 相似文献
50.
J Zimmerman 《Biochemical pharmacology》1992,44(9):1839-1842
The effect of sulfasalazine and olsalazine on the transport of [3H]folic acid and of [3H]methotrexate (MTX) was investigated in organ-cultured endoscopic biopsy specimens of small intestinal mucosa from normal subjects. Biopsy specimens obtained from patients undergoing routine diagnostic upper gastrointestinal endoscopy were organ-cultured at pH 5.5 and the effect of these two drugs on the initial rate of uptake of the two folates was determined. Both drugs inhibited the transport of [3H]folic acid with similar Ki values (1.38 and 1.32 mM for sulfasalazine and olsalazine, respectively). However, the uptake of [3H]MTX was only partially inhibited by sulfasalazine and was unaffected by olsalazine. Sulfasalazine inhibited 26.2% of the total flux of MTX, in close agreement with the fraction of MTX flux that has been shown previously to be inhibited by folic acid. These data corroborate previous findings of heterogeneity of transport of MTX in the mucosa of the human small intestine. 相似文献