全文获取类型
收费全文 | 27139篇 |
免费 | 1261篇 |
国内免费 | 164篇 |
专业分类
耳鼻咽喉 | 302篇 |
儿科学 | 774篇 |
妇产科学 | 547篇 |
基础医学 | 3238篇 |
口腔科学 | 1012篇 |
临床医学 | 1943篇 |
内科学 | 6836篇 |
皮肤病学 | 381篇 |
神经病学 | 2372篇 |
特种医学 | 1000篇 |
外科学 | 4285篇 |
综合类 | 97篇 |
一般理论 | 11篇 |
预防医学 | 1790篇 |
眼科学 | 326篇 |
药学 | 1619篇 |
中国医学 | 90篇 |
肿瘤学 | 1941篇 |
出版年
2023年 | 228篇 |
2022年 | 525篇 |
2021年 | 939篇 |
2020年 | 524篇 |
2019年 | 759篇 |
2018年 | 981篇 |
2017年 | 634篇 |
2016年 | 722篇 |
2015年 | 851篇 |
2014年 | 1142篇 |
2013年 | 1324篇 |
2012年 | 2184篇 |
2011年 | 2123篇 |
2010年 | 1299篇 |
2009年 | 1067篇 |
2008年 | 1793篇 |
2007年 | 1749篇 |
2006年 | 1668篇 |
2005年 | 1537篇 |
2004年 | 1344篇 |
2003年 | 1228篇 |
2002年 | 1172篇 |
2001年 | 232篇 |
2000年 | 169篇 |
1999年 | 214篇 |
1998年 | 196篇 |
1997年 | 164篇 |
1996年 | 158篇 |
1995年 | 158篇 |
1994年 | 117篇 |
1993年 | 109篇 |
1992年 | 93篇 |
1991年 | 77篇 |
1990年 | 110篇 |
1989年 | 73篇 |
1988年 | 70篇 |
1987年 | 58篇 |
1986年 | 75篇 |
1985年 | 57篇 |
1984年 | 70篇 |
1983年 | 50篇 |
1982年 | 56篇 |
1981年 | 41篇 |
1980年 | 49篇 |
1979年 | 36篇 |
1978年 | 47篇 |
1977年 | 25篇 |
1975年 | 23篇 |
1973年 | 25篇 |
1972年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
We examined the effectiveness of self-operated auditory prompts when used to decrease the off-task and aberrant behaviors of two students with moderate mental retardation. Its purpose was to determine if self-operated auditory prompts could be effectively used by these individuals to decrease their off-task and aberrant behaviors in work settings and during transitional times between settings. A multiple-probe across settings design with a reversal and replication was used to evaluate the effectiveness of the self-operated auditory prompting system on aberrant student behaviors in school and community settings. Previous findings were replicated in this study that demonstrate that stimulus control can be achieved through the use of self-operated auditory prompts, and demonstrates that these prompts can serve to occasion a decrease in aberrant behaviors when used by individuals with moderate mental retardation in school and community settings. 相似文献
103.
104.
105.
Elio Ricchi M.D. Salvatore Fundarò M.D. Andrea Spallanzani M.D. Alfonso Carriero M.D. Alberto Farinetti M.D. Francesco Ferrara M.D. Carlo Pezcoller M.D. 《Diseases of the colon and rectum》1996,39(3):353-357
PURPOSE: Loss of a certain amount of cutaneous tissue of the perineal region may be remedied by first intention with creation of cutaneous flaps, thus preventing second intention healing. METHODS: We present three emblematic cases in which the posterior perineal region was reconstructed by means of vertical subcutaneous pedicle flaps, subsequent to cutaneous tissue loss after surgery for extensive condilomas or neoplastic pathologies. RESULTS: Tissue loss was repaired by means of a V-Y type vertical subcutaneous pedicle flap, constructed laterally of the extirpation zone and advanced in a median direction. In all cases, no ischemia or infection of flaps occurred; sphincteral continence and long-term aesthetic results have proved to be satisfactory. CONCLUSIONS: Vertical pedicle subcutaneous flaps are well vascularized, extremely mobile, and easy to perform and have no serious postoperative complications. 相似文献
106.
Tomasi E Barros FC Victora CG 《Cadernos de saúde pública / Ministério da Saúde, Funda??o Oswaldo Cruz, Escola Nacional de Saúde Pública》1996,12(Z1):15-19
Socioeconomic and family characteristics of two cohorts of babies born in 1982 and 1993 in Pelotas (Southern Brazil) were compared. There were 6,011 births in 1982 and 5,304 in 1993. In relation to family income, there were fewer poor babies in 1993; 60.8 % of the families earned less than 3 times the monthly minimum wage in 1993, as compared to 69.5% in 1982. Sanitary conditions also improved over the decade, and the proportion of families with running water and flush toilets increased by 10%. On the other hand, there were no changes in the proportion of single-parent families or availability of home appliances like radios, stoves, and refrigerators. The mean number of persons per household increased from 3.0 in 1982 to 3.2 in 1993. In general, comparison of the two birth cohorts in this city suggests an improvement in quality of living over the time period for families with newborns. This finding should be taken into account when studying the evolution of health indicators over the course of the decade. 相似文献
107.
108.
Luciano De Carlis Ernesto Del Favero Gianfranco Rondinara Luca S. Belli Cosimo V. Sansalone Bruno Zani Alberto Cazzulani Giorgio Brambilla Antonio Rampoldi Lino Belli 《Transplant international》1992,5(1):9-14
Spontaneous portosystemic shunts are commonly found in cirrhotic patients. Not yet established is their role after orthotopic liver transplantation (OLTx), especially when an increase in portal pressure develops, as during early acute rejection. In this study, 34 cirrhotic patients in a series of 70 OLTx are considered. Each patient had preoperative angiographic assessment, and, in 21 (62%), large spontaneous portosystemic shunts were evident. In 12 cases the shunts were not affected by the surgical procedure and were present during the postoperative period; in 9 the hepatectomy itself involved interruption of the shunts. The patient population was divided into two groups: patients with postoperative shunts (n=12) and those without (n=22). The two groups were similar in age, sex, Child's stage, transplantation variables, and number and grade of rejection episodes. However, mean transaminases (AST) values in the first 2 weeks were significantly higher levels in shunt versus nonshunt patients (421±335 vs 183±126; P<0.025), and this was even more evident when rejection occurred (626±375 vs 195±129; P<0.001). Furthermore, during an acute rejection reaction, three cases showed a true steal phenomenon through the large reopened shunts with ischemic damage to the grafts. The data indicate a possible detrimental effect of the spontaneous shunts on graft perfusion and suggest the prophylactic surgical interruption of the residual shunts during the transplantation. 相似文献
109.
The locomotor activity of C57B1/6J and DBA/2J mice was studied, under the influences of heroin, amphetamine, strychnine, or ethanol, and of combinations of the opiate with each one of the other drugs. Heroin treatment was followed by the typical running fit in the C57 mice, while the DBA strain was unaffected. Amphetamine enhanced the activity in the C57 strain only. The combination of heroin with amphetamine or ethanol increased the locomotor activity only in the DBA strain, while heroin + strychnine exerted a clear stimulating effect on the activity of the C57 mice. The strychnine + heroin mixture was more toxic than heroin alone when the lethal doses (LD50) were determined in the 2 strains. 相似文献
110.