全文获取类型
收费全文 | 1288738篇 |
免费 | 95049篇 |
国内免费 | 2044篇 |
专业分类
耳鼻咽喉 | 18311篇 |
儿科学 | 42672篇 |
妇产科学 | 38183篇 |
基础医学 | 188712篇 |
口腔科学 | 35613篇 |
临床医学 | 110444篇 |
内科学 | 253766篇 |
皮肤病学 | 26698篇 |
神经病学 | 100428篇 |
特种医学 | 50327篇 |
外国民族医学 | 367篇 |
外科学 | 198801篇 |
综合类 | 26623篇 |
现状与发展 | 1篇 |
一般理论 | 317篇 |
预防医学 | 94427篇 |
眼科学 | 29276篇 |
药学 | 98507篇 |
2篇 | |
中国医学 | 2514篇 |
肿瘤学 | 69842篇 |
出版年
2018年 | 12135篇 |
2016年 | 10368篇 |
2015年 | 11967篇 |
2014年 | 16529篇 |
2013年 | 25035篇 |
2012年 | 34601篇 |
2011年 | 37007篇 |
2010年 | 21788篇 |
2009年 | 20508篇 |
2008年 | 35905篇 |
2007年 | 38926篇 |
2006年 | 39400篇 |
2005年 | 38656篇 |
2004年 | 37210篇 |
2003年 | 36126篇 |
2002年 | 35718篇 |
2001年 | 58198篇 |
2000年 | 59648篇 |
1999年 | 50782篇 |
1998年 | 14398篇 |
1997年 | 12959篇 |
1996年 | 13195篇 |
1995年 | 12449篇 |
1994年 | 11833篇 |
1993年 | 10945篇 |
1992年 | 41028篇 |
1991年 | 40402篇 |
1990年 | 39925篇 |
1989年 | 38754篇 |
1988年 | 36136篇 |
1987年 | 35371篇 |
1986年 | 33768篇 |
1985年 | 32167篇 |
1984年 | 23978篇 |
1983年 | 20859篇 |
1982年 | 12430篇 |
1981年 | 10967篇 |
1979年 | 22667篇 |
1978年 | 15915篇 |
1977年 | 13756篇 |
1976年 | 12985篇 |
1975年 | 14216篇 |
1974年 | 16704篇 |
1973年 | 16090篇 |
1972年 | 15332篇 |
1971年 | 14234篇 |
1970年 | 13225篇 |
1969年 | 12737篇 |
1968年 | 11985篇 |
1967年 | 10481篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Establishing the diagnosis of drug-induced pneumonitis is always difficult and requires that the following criteria be met: administration of the drug on a long-term basis; knowledge that the drug is able to induce pulmonary disorders; occurrence during therapy of interstitial pneumonitis with clinical, radiological and functional characteristics of this type of lung disease; exclusion of all other causes of interstitial pneumonitis (cardiac failure, infections, collagen vascular diseases, malignancies); bronchoalveolar lavage specimen, revealing lymphocytosis with an inverted CD4/CD8 lymphocyte ratio, isolated or associated with neutrophil and/or eosinophil alveolitis; finally, full recovery within several weeks or months after drug withdrawal unless irreversible pulmonary fibrosis has occurred. Certain specific characteristics correspond to the therapeutic class of the drug, i.e. antimicrobial, cardiovascular, antiinflammatory, neurological, metabolic, antiallergy or some other drugs. 相似文献
992.
The effect of body position (right and left lateral decubitus positions) on arterial oxygen tension (PaO2) and the relationship between this postural effect on gas exchange and pulmonary function were evaluated in 21 patients who had unilateral pleural effusions without roentgenographic and bronchoscopic evidence of bronchopulmonary disorders. Our results indicated that a positional influence on gas exchange existed in these patients. We failed to find a consistent relationship between the size of effusion estimated by chest roentgenogram and alterations in PaO2 during different positions. Postural change did affect gas exchange in the patients with unilateral pleural effusions and this postural effect on gas exchange was highly correlated with their FEV1 and FVC. This may be of clinical significance in managing such patients. 相似文献
993.
A C Meneses M A Lopes A Rocha M C Fatureto G P Lopes E R Lopes E Chapadeiro 《Arquivos de gastroenterologia》1989,26(1-2):13-16
This is a review of 4.690 necropsies and 24.209 surgical pathology specimens describing the association between megacolon chagasic and malignant tumors of the large bowel. The prevalence of malignant tumors of the large bowel was not higher in megacolon. 相似文献
994.
In a study of rock music preferences, listening/watching behavior, and views on destructive rock lyrics, 894 adolescents in grades 9 through 12 in rural, urban, suburban public, and metropolitan parochial schools were administered a questionnaire. Demographic information on parents was also collected. It was found that 17.5% of the students were fans of rock music with lyrics that promote homicide, suicide, or satanic practices (HSSR). Loglinear and multiple regression analyses were used to analyze the data. Parents' marital status, student sex, race, and school environment (urban, rural, suburban, etc.) were found to be significant predictors of HSSR status. As compared with non-HSSR fans, the HSSR fans were more likely to have parents who were “Never married” or “Remarried” and less likely to have parents in the “married” category. The HSSR fans were more likely to be male, white, and enrolled in urban schools but not parochial schools than expected; HSSR status also significantly predicted other music-related attitudes and behaviors. The HSSR fans reported liking both the sound and the lyrics of rock music more often than did non-HSSR fans, as did females and urban students. The HSSR fans more often felt that children under 10 years of age should be allowed to listen to HSSR lyrics, and they more frequently expressed the conviction that HSSR music does not affect adolescents' homicidal or self-destructive behavior. The HSSR fans and females reported more nearly complete knowledge of lyrics than did non-HSSR fans and males. The HSSR fans reported that they watch more MTV than did any other group except rural students. 相似文献
995.
This study determined nursing research priorities and focused on the development of a nursing research program within a single institution. Of the 715 nurses within the Department of Nursing, 286 (40%) responded to the first round of a two-round Delphi technique, and 137 (48%) responded to the second. The following clinical priorities were determined: prevention and treatment of pressure sores, pain management, treatment of nosocomial infections, and patient education. Nonclinical priorities included staffing and its effects on turnover and patient care, job satisfaction, and factors influencing the quality of nursing care. Serendipitous findings underscored the relevance of the Department of Nursing's conceptual framework to nursing practice and research, revealed the need for dissemination of current research results, and suggested that nurses want to participate in research without assuming responsibility beyond their expertise. 相似文献
996.
J. I. Bilbao M.D J. Rodriguez-Cabello J. Longo G. Zornoza J. Páramo F. J. Lecumberri 《Abdominal imaging》1989,14(1):326-328
We present a case report of a patient suffering from portal and superior mesenteric vein thrombosis secondary to splenectomy. No surgical procedure could be performed due to the extension of thrombus.Local fibrinolysis treatment with urokinase through a percutaneous transhepatic approach was decided upon, and this procedure had a successful patient outcome. 相似文献
997.
998.
A 64-year-old woman presented in shock. The computed tomography (CT) scan confirmed rupture of the left diaphragm with strangulation. Three days after surgery, the patient developed herniation of abdominal contents on the right side with cardiorespiratory collapse. Marlex mesh was used to repair on the right side. Postoperatively, she needed partial gastrectomy for massive duodenal ulcer bleeding. A dual chamber pacemaker was used to correct the complete heart block. 相似文献
999.
Insulin-like growth factors (IGF-I and -II) are peptide growth factors that may be important for neonatal development. Specific high affinity IGF binding proteins (BPs) have been characterized in serum and extracellular fluids. The major serum binding complex in the adult has an apparent Mr of 150 K, while the predominant BP in the neonate is approximately 30 K. In the rat, the transition from the neonatal BP to the adult form occurs during the third postnatal week, concomitant with an increase in serum IGF-I and a decrease in serum IGF-II concentrations. Using specific RIAs and Western ligand blot analyses we have characterized the changes in serum IGF and IGF BPs, respectively, during the early postnatal period. Seven BPs were identified in serum with apparent Mr values of 42, 41, 40, 38, 28, 26, and 22 K. After deglycosylation, the 42, 41, 40, and 38 K BPs were reduced to two bands with apparent Mr values of 35 and 32 K, while the 28, 26, and 22 K BP were unchanged. In the neonate, the 28, 26, and 22 K BPs were present, with the 28 K BP in highest concentration. With increasing age, the 28 K BP decreased and the 42, 41, 40, and 38 K BPs appeared at approximately 19 days of age. Comparison of Western ligand blots of neonatal serum, BRL-3A conditioned media, rat amniotic fluid, and rat cerebrospinal fluid (CSF) demonstrated that all contained a prominent 28 K BP. A polyclonal antibody (alpha Hec 1) developed against the 31 K human IGF-BP (hBP-31) immunoprecipitated the 28 K BP from neonatal rat serum, BRL-3A media, rat amniotic fluid, and rat CSF, but did not react with adult rat serum. These findings suggest that, in the rat, the predominant neonatal serum BP is structurally and immunologically similar to the major BRL-3A, amniotic fluid, and CSF BPs, but distinct from the predominant adult serum BP. 相似文献
1000.
Elevated serum levels of keratan sulfate (KS) and hyaluronate (HA) in patients with osteoarthritis (OA) have been reported. We measured KS and HA in dogs to determine if there was an elevation of these serum glycosaminoglycans in a canine model of OA. A single intraarticular injection of 1 mg of chymopapain into a shoulder joint increased serum KS by tenfold, and HA by less than twofold, in 24 hours. Serum KS and HA levels were 3-5-fold higher in dogs younger than 2 months of age than in older dogs. Serum KS and HA concentrations and synovial fluid KS concentrations were unrelated to spontaneous cartilage degeneration in 1-year-old dogs. Higher KS levels in synovial fluid correlated with higher KS levels in serum (r = 0.54, P less than 0.025). The mean KS concentration in sera of older dogs (greater than 3 years old) with OA was 37% higher than that in disease-free controls, but the difference between the groups was not statistically significant. Thus, elevated levels of serum KS and HA do not appear to have clinical significance in this model of OA. 相似文献