全文获取类型
收费全文 | 42965篇 |
免费 | 3079篇 |
国内免费 | 147篇 |
专业分类
耳鼻咽喉 | 464篇 |
儿科学 | 1377篇 |
妇产科学 | 1226篇 |
基础医学 | 5916篇 |
口腔科学 | 493篇 |
临床医学 | 6271篇 |
内科学 | 8243篇 |
皮肤病学 | 712篇 |
神经病学 | 4357篇 |
特种医学 | 810篇 |
外国民族医学 | 1篇 |
外科学 | 3456篇 |
综合类 | 763篇 |
一般理论 | 42篇 |
预防医学 | 5010篇 |
眼科学 | 882篇 |
药学 | 2981篇 |
中国医学 | 79篇 |
肿瘤学 | 3108篇 |
出版年
2023年 | 223篇 |
2022年 | 469篇 |
2021年 | 863篇 |
2020年 | 478篇 |
2019年 | 799篇 |
2018年 | 931篇 |
2017年 | 721篇 |
2016年 | 803篇 |
2015年 | 974篇 |
2014年 | 1310篇 |
2013年 | 1992篇 |
2012年 | 3012篇 |
2011年 | 3172篇 |
2010年 | 1604篇 |
2009年 | 1558篇 |
2008年 | 2848篇 |
2007年 | 3071篇 |
2006年 | 3148篇 |
2005年 | 3098篇 |
2004年 | 3012篇 |
2003年 | 2833篇 |
2002年 | 2621篇 |
2001年 | 381篇 |
2000年 | 276篇 |
1999年 | 375篇 |
1998年 | 483篇 |
1997年 | 417篇 |
1996年 | 378篇 |
1995年 | 361篇 |
1994年 | 267篇 |
1993年 | 297篇 |
1992年 | 206篇 |
1991年 | 205篇 |
1990年 | 185篇 |
1989年 | 179篇 |
1988年 | 191篇 |
1987年 | 152篇 |
1986年 | 131篇 |
1985年 | 150篇 |
1984年 | 190篇 |
1983年 | 185篇 |
1982年 | 237篇 |
1981年 | 176篇 |
1980年 | 184篇 |
1979年 | 110篇 |
1978年 | 107篇 |
1977年 | 112篇 |
1976年 | 86篇 |
1975年 | 71篇 |
1974年 | 78篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Pillemer S Gulko P Ligier S Yarboro C Gourley M Goldbach-Mansky R Siegel R Hirsch R Pucino F Tilley B Wilder RL 《The Journal of rheumatology》2003,30(1):41-43
OBJECTIVE: To screen for potential efficacy and assess the feasibility of intravenous (IV) doxycycline as a treatment for rheumatoid arthritis (RA). METHODS: The study was a (stratified, block) randomized, double blind, 12 week, pilot trial of IV doxycycline 300 mg/day versus identical appearing IV placebo given over 2 h for 14 days. The primary comparison was to a hypothesized placebo rate of 20% as described by Paulus. If a total of 14 consecutive subjects receiving doxycycline treatment did not respond, it would be considered futile to proceed to a Phase III trial. We planned a placebo group of 14 subjects to verify the placebo response rate and estimate sample size required for a definitive Phase III trial, if such a trial was warranted based on the pilot study. American College of Rheumatology (ACR) RA response criteria were used. After 23 subjects entered, the study was closed due to recruitment difficulties. RESULTS: At baseline, mean (SD) tender joint count was 37 (11.9), swollen joint count 30 (9.6), morning stiffness 317 (319) min, and erythrocyte sedimentation rate 72 mm/h (27.5). Randomization resulted in 10 subjects receiving doxycycline and 13 receiving placebo. Treatment was stopped in 8 subjects: in 6, treatment was ineffective (one taking doxycycline, 5 placebo), and in 2, rashes occurred (one taking doxycycline, one placebo). Only one subject met ACR response criteria in the doxycycline group and none in the placebo group. Having no responders in the placebo group was consistent with placebo response rate of 20% or less. Several patients required peripherally inserted central catheters for venous access. CONCLUSION: The efficacy of IV doxycycline as a treatment for RA could not be ruled out. However, as the proportion of responders was small, it is unlikely that potential efficacy of IV doxycycline would outweigh potential disadvantages of IV administration. 相似文献
992.
Peterson ED Lytle BL Biswas MS Coombs L 《The American journal of geriatric cardiology》2004,13(1):11-15
The elderly, women, and minorities are all less likely to be enrolled in randomized clinical trials (RCTs). Whether differential patient interest in RCTs contributes to these disparities is unclear. The authors surveyed 660 patients' willingness to consider two potential cardiac RCTs of medical therapy vs. percutaneous coronary angioplasty or coronary artery bypass surgery, respectively. The cohort's mean age was 67 years (43% aged ≥70 years; 35% women; and 28% nonwhite). Compared with younger patients, those aged ≥70 years were equal or more likely to consider both the percutaneous coronary angioplasty (46% vs. 41%) and coronary artery bypass surgery RCTs (35% vs. 31%). Race also had no significant impact on trial enrollment, yet women were significantly less likely than men to participate in either RCT. In conclusion, patient willingness to consider RCT participation does not explain underenrollment of elderly and minority patients. Women, however, were more reluctant to consider RCTs, an area requiring further study. 相似文献
993.
James W. Craig Joseph Larner Ellen F. Locker Barbara Widom M.Jocelyn Elders 《Metabolism: clinical and experimental》1984,33(12):1084-1096
The binding and action of insulin and of the insulin-like growth factor, multiplication-stimulating activity (MSA), were studied in cultured skin fibroblasts from an infant with leprechaunism and associated insulin resistance. Three actions of insulin were reduced in the leprechaun cells: activation of glycogen synthase was 30% as great as in control fibroblasts, the increase in 2-deoxyglucose transport was 33% of the control value, and the uptake of alpha-aminoisobutyric acid was sevenfold less sensitive to enhancement. On a molar basis, MSA was at least as effective as insulin in activating glycogen synthase in control fibroblasts; in the patient's cells there was a reduction in activation that paralleled the changes observed with insulin. To localize the site of insulin resistance, the binding of both [125I]-insulin and [125I]-MSA to fibroblasts was measured and found to be reduced in the leprechaun cells. However, the impairment of the actions of insulin and MSA in the patient's cells was not explained solely by the diminished binding of the two polypeptides. Since the hexose transport system and the terminal enzymes studied thus far are intact, the defect is postulated to involve the post-binding coupling mechanism and mediator formation. 相似文献
994.
Broers B Helbling B François A Schmid P Chuard C Hadengue A Negro F;Swiss Association for the Study of the Liver 《Journal of hepatology》2005,42(3):323-328
BACKGROUND/AIMS: Treatment with interferon-alpha (IFN-alpha) may eradicate HCV in most acute hepatitis C patients, thus preventing chronic hepatitis and avoiding less efficacious combination therapy. METHODS: In a prospective study, we evaluated the impact of barriers to successful start and completion of treatment of acute and subacute (<12 months from infection) hepatitis C with pegylated IFN-alpha2b, 1.5 microg/kg, QW, for 24 weeks. RESULTS: Out of 27 patients (22 were active intravenous drug users [IVDU]), 5 cleared HCV spontaneously. Antiviral treatment was indicated in 22 patients: six refused therapy for fear of side effects, whereas two others were lost to observation. Eight patients completed the treatment or received >80% of the scheduled drug: seven (88%) were sustained virological responders 24 weeks after the end of treatment. Six patients (all IVDU) stopped prematurely due to side effects: only one had a sustained virological response. Based on an intent-to-treat analysis, and considering all 14 patients in whom at least one dose of drug was administered, only 8 (57%) became sustained virological responders. CONCLUSIONS: Treatment of acute hepatitis C with pegylated IFN-alpha is highly beneficial, but its effectiveness is affected by a poor rate of acceptance and/or adherence to currently available regimens, especially in IVDU and women. 相似文献
995.
Di Candia Domenico Boracchi Michele Ciprandi Barbara Giordano Gaia Zoja Riccardo 《International journal of legal medicine》2022,136(5):1291-1296
International Journal of Legal Medicine - Synthetic cathinones are a class of psychoactive drugs that have become, in recent years, of quite common observation in medical and toxicological forensic... 相似文献
996.
Fiorucci S Mencarelli A Meneguzzi A Lechi A Renga B del Soldato P Morelli A Minuz P 《Journal of the American College of Cardiology》2004,44(3):635-641
OBJECTIVES: The goal of this study was to test the hypothesis that NCX-4016 may have broader anti-inflammatory and antithrombotic effects as well as better gastric tolerability than aspirin in humans. BACKGROUND: NCX-4016 is an aspirin derivative containing a nitric oxide-releasing moiety that prevents platelet activation and modulates tissue factor (TF) expression and cytokine release from lipopolysaccharide (LPS)-stimulated monocytes. METHODS: This was a blind-observer, placebo-controlled, parallel-group study in which 48 healthy subjects were randomized to receive NCX-4016 800 mg twice a day, NCX-4016 800 mg twice a day plus aspirin 325 mg, aspirin 325 mg, or placebo for 21 days. RESULTS: Similar to aspirin alone, NCX-4016 effectively inhibited platelet aggregation induced by 0.6 mmol/ arachidonic acid, clot-stimulated thromboxane (TX) B2 generation in whole blood, and urinary excretion of 11-dehydro-TXB2. Unlike aspirin alone, the administration of NCX-4016 significantly inhibited TF expression in monocytes stimulated ex vivo with 10 micromol/l LPS (determined by flow-cytometry analysis of TF on CD14 positive cells). NCX-4016 also inhibited the rapid TF expression induced in monocytes by a proteinase activated receptor agonist (thrombin receptor activator protein, 2 micromol/l) as well as LPS-induced expression of CD11b . Ex vivo, release of MCP-1 and interleukin-6 were significantly inhibited by NCX-4016, but not by aspirin. NCX-4016 was not associated with gastric damage, and significantly reduced gastric injury when co-administered with aspirin, although both drugs reduced gastric PGE2 production to the same extent. CONCLUSIONS: NCX-4016 is equally effective as aspirin in inhibiting cyclooxygenase activity. However, NCX-4016 causes less gastric damage and prevents monocyte activation. Larger multicenter trials are warranted to establish clinical efficacy and safety of NCX-4016. 相似文献
997.
Francesco Minni Riccardo Casadei Barbara Perenze Vincenzo Maria Greco Nicola Marrano Alessandra Margiotta Domenico Marrano 《Pancreatology》2004,4(6):509-520
BACKGROUND: The aim of the study is to analyze pancreatic metastases and their clinical, radiological, therapeutic and prognostic features. METHODS: Three cases of pancreatic metastases observed and a world literature review of 333 cases were recorded. RESULTS: Pancreatic metastases are due more frequently to renal cell carcinoma; they are usually metachronous and characterized by a long period of time between the resection of the primary tumor and their detection. The differential diagnosis with other pancreatic masses is difficult, but an accurate anamnesis, some peculiar findings of imaging techniques and percutaneous fine needle aspiration could allow preoperative diagnosis. Pancreatic resections are the treatment of choice allowing the better palliation and improving survival. 150/234 pancreatic metastases underwent pancreatic resections (resectability index = 64.1%); 88/132 patients are alive with a mean follow-up of 27.1 months; of the 44 dead patients the mean survival time was 21.3 months. Among pancreatic metastases the primary tumor with better prognosis is renal cell carcinoma. CONCLUSION: Pancreatic metastases are rare; their preoperative diagnosis is difficult but useful and possible. Surgical resection is suggested because the patient still may have a prolonged survival. 相似文献
998.
999.
Bain BJ 《American journal of hematology》2004,77(1):82-85
Chronic eosinophilic leukemia is a neoplastic condition with persistent eosinophilia as the major hematological abnormality and with the eosinophils being part of the neoplastic clone. Some cases can be recognized by traditional hematological criteria, but many can be recognized only when a clonal cytogenetic or molecular genetic abnormality is demonstrated. A range of cytogenetic and molecular genetic abnormalities has been recognized, including both those seen in other myeloid malignancies (such as trisomy 8, monosomy 7, and 20q-) and those that are particularly linked to eosinophil differentiation (such as rearrangements of PDGFRB, FGFR1, and PDGFRA, the latter with formation of a FIP1L1-PDGFRA fusion gene). The discovery of the FIP1L1-PDGFRA fusion gene has led to the recognition that many patients who would previously have been regarded as having idiopathic hypereosinophilia actually have chronic eosinophilic leukemia. The same fusion gene has also been found in patients with hypereosinophilia and atypical bone marrow mast cells but whether this syndrome should be regarded as a variant of eosinophilic leukemia or as a variant of systemic mastocytosis remains to be established. 相似文献
1000.
Increased understanding of the mechanisms by which T lymphocytes recognize virus and tumor-specific antigens has fueled the use of adoptive immunotherapy for viral and malignant diseases. An ideal candidate for such treatment is Epstein-Barr virus (EBV). EBV-associated post-transplant lymphoproliferative disorder (PTLD) is a serious complication post-solid organ transplant (SOT) or hematopoietic stem cell transplant (HSCT). The disease is essentially the result of suppression of cytotoxic T-cell function and despite various treatment strategies the course may still be fulminant and lethal. Therefore, an adoptive immunotherapeutic approach using ex vivo derived EBV-specific CTL offers a promising solution not only for the treatment but also as prophylaxis for PTLD. The infusion of EBV-CTL has been demonstrated to be safe and effective in allogeneic HSCT recipients and their use post-SOT is being evaluated. 相似文献