首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   37077篇
  免费   2134篇
  国内免费   201篇
耳鼻咽喉   425篇
儿科学   1151篇
妇产科学   997篇
基础医学   3687篇
口腔科学   1210篇
临床医学   3251篇
内科学   7999篇
皮肤病学   670篇
神经病学   2209篇
特种医学   1313篇
外国民族医学   4篇
外科学   6769篇
综合类   854篇
现状与发展   3篇
一般理论   27篇
预防医学   2498篇
眼科学   1355篇
药学   2854篇
  1篇
中国医学   266篇
肿瘤学   1869篇
  2024年   39篇
  2023年   413篇
  2022年   1051篇
  2021年   1642篇
  2020年   983篇
  2019年   1255篇
  2018年   1566篇
  2017年   1136篇
  2016年   1232篇
  2015年   1329篇
  2014年   1681篇
  2013年   2048篇
  2012年   3095篇
  2011年   2991篇
  2010年   1688篇
  2009年   1462篇
  2008年   2221篇
  2007年   2291篇
  2006年   2020篇
  2005年   1787篇
  2004年   1622篇
  2003年   1348篇
  2002年   1177篇
  2001年   363篇
  2000年   306篇
  1999年   280篇
  1998年   197篇
  1997年   132篇
  1996年   141篇
  1995年   107篇
  1994年   95篇
  1993年   77篇
  1992年   147篇
  1991年   160篇
  1990年   128篇
  1989年   123篇
  1988年   104篇
  1987年   97篇
  1986年   88篇
  1985年   116篇
  1984年   77篇
  1983年   52篇
  1982年   53篇
  1981年   55篇
  1980年   41篇
  1979年   50篇
  1978年   40篇
  1975年   35篇
  1974年   36篇
  1973年   35篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Subacute sensory neuronopathy is a paraneoplastic syndrome, which occurs mostly in lung, breast, ovarian malignancies and lymphoma. A 75-yr-old woman who was at the twentieth month of her postoperative follow-up owing to colon adenocarcinoma admitted with subacute sensory neuronopathy. Six months later from the first, neuropathic symptoms liver metastases developed. To the best of our literature review subacute sensory neuronopathy as a preceding sign of recurrence in colon adenocarcinoma has not previously been reported. We conclude that, in the case of subacute sensory neuronopathy without an obvious underlying etiological factor, an occult malignity should always be researched in clinical practice.  相似文献   
102.
Abstract A review of the literature highlights the need for research, particularly on the acute bronchodilatory effect of salmeterol on bronchoconstriction in the pediatric age group. The present study attempted to evaluate the acute bronchodilatory effect of salmeterol on methacholine-induced bronchoconstriction in childhood asthma and to compare it with the effect of salbutamol. Forty-four asymptomatic children with mild-to-moderate asthma (23 boys and 21 girls; aged7–17 years) were studied. At the beginning, the baseline forced expiratory volume in 1 s (FEV1) was measured, and the methacholine challenge was performed by doubling the dose to determine PC20 (provocative concentration of inhaled methacholine required to reduce FEV! by 20%). At the same time, the transcutaneous arterial oxygen saturation (Sao2) was also measured. Each subject inhaled a single dose of 25 μ salmeterol (n: 23, group I) or 100 μg salbutamol (n: 21, group II) following the Sp2 measurement. The same measurements (FEV1, Sao2) were repeated 5 and 20 min after the inhalation. After inhalation of salmeterol or salbutamol, the differences between the values of FEV1 and SaO2 after 5 and 20 min were insignificant in both group I and group II (P > 0.05), although there was a significant improvement in both FEV1 and SaO2 after 5 and 20 min (P < 0.005). From these findings it was concluded that salmeterol can be considered as effective as salbutamol on methacholine-induced bronchoconstriction.  相似文献   
103.
We present a rare case of a placental teratoma found within the fetal membranes of an otherwise normal placenta. Lack of a recognizable umbilical cord and no recognizable skeletal development are used as differential diagnostic criteria for a placental teratoma. In our case, an umbilical cord was absent; nevertheless, the tumor contained two vascular channels covered only by fetal membranes without Wharton's jelly.  相似文献   
104.
Harrison J  Ali A  Bonomi P  Prinz R 《The American surgeon》2000,66(5):432-6; discussion 436-7
Metastases to the adrenal glands usually signal disseminated disease. However, isolated metastases do occur that may be curable with adrenalectomy. Functional imaging with positron emission tomography (PET) can differentiate benign from malignant pathology and isolated from disseminated metastases. The purpose of this study was to determine whether PET scanning can influence the outcome of adrenalectomy for metastatic disease. We conducted a retrospective review of eight patients undergoing adrenalectomy for presumed isolated metastatic disease from 1985 through 1997. The patients included six women and two men with an average age of 58 (range, 36-74). Their primary tumors were six lung carcinomas, one renal cell carcinoma, and one colon carcinoma. The adrenal masses were located on the right in six patients, on the left in one, and bilaterally in one. Before operation, all patients were evaluated by chest and abdominal CT. Four patients were also evaluated by PET scan. Six right, one left, and one bilateral adrenalectomies were performed. Associated organ resections included two right partial nephrectomies and one right total nephrectomy, one left partial nephrectomy, two distal pancreatectomies, one splenectomy, and two partial hepatic resections. All eight patients survived operation. There were no major perioperative complications, but one patient required readmission for congestive heart failure. Three of the four patients who did not have PET scanning died from 4 to 48 months after operation with disseminated disease from lung, colon, and renal carcinoma respectively. The remaining patient who did not have PET scanning is alive and well 11 years later. Two of the four patients who had PET scans showing isolated disease are alive at 28 and 43 months after operation, whereas the other two died of disseminated disease at 29 and 36 months after operation. We conclude that 1) adrenalectomy can provide survival benefit in patients with isolated metastases, and 2) PET scanning is useful in confirming isolated metastatic disease and selecting patients for adrenalectomy.  相似文献   
105.
OBJECTIVES: In Pakistan, the role of men has always been considered to dominate in the decision-making process pertaining to women's fertility and birth spacing. This study was done to explore men's knowledge, perceptions and behavior on various reproductive health issues. METHODS: A cross-sectional survey was carried out among 180 married adult males in 12 rural districts of Pakistan in 2000. The study was qualitative, utilizing tools such as in-depth and key-informant interviews. RESULTS: The findings pointed out gaps in knowledge and misconceptions among men on a range of reproductive health issues and stress the need for health education. The findings suggest that strategies such as couple counseling, door-to-door campaigns by village-based male family planning workers and small group meetings could be effective. This study indicates a pressing need for incorporating effective intervention strategies, both at the community and the clinic level, backed with efficient counseling, motivation, and provision of services with appropriate education of males in rural areas. CONCLUSION: The findings suggest that investment into promotion of healthy fertility control practices among men will be effective in the near future, as they are interested in acquiring new knowledge and are willing to become partners.  相似文献   
106.
患者,女,62岁,因颈部肿块就诊。既往32年前因胆囊疾病行胆囊切除术。15年前因多发性甲状腺结节行甲状腺次全切除术,病理结果为小灶性甲状腺癌。10年前因血尿诊断为肾癌,行右肾切除术。.体格检查:锁骨上可触及一5.0cm×3.0cm大小肿块(穿刺细胞学检查结果不能定性)。.辅助检验:腹  相似文献   
107.
McN-A-343, which is a ligand at muscarinic receptors on myenteric ganglia, was found to concentration-dependently (1-44 microM) elicit non-adrenergic relaxation of the longitudinal muscle of rat distal colon, having been precontracted with carbachol (1 microM). This effect was partly antagonized by the muscarinic receptor antagonist, pirenzepine (0.3 microM), the nerve blocker, tetrodotoxin (1 microM), or by drugs which interfere with purinergic neurotransmission (apamin [0.5 microM], reactive blue 2 [50 microM]). Blockade of nitric oxide synthase (L-NNA [100 microM]), or of the cAMP (H-89 [1 microM]), or cGMP (ODQ [10 microM]) second messenger pathways did not affect the relaxatory response to McN-A-343 (14 microM). An additional, non-neurogenic component of the relaxation to this compound on carbachol induced tone is suggested to reflect a partial antagonism of the muscarinic receptors on the gut muscle by McN-A-343.  相似文献   
108.
GM1 gangliosidosis is an autosomal recessive glycosphingolipid storage disease caused by defects in the enzyme beta-galactosidase. Three clinical forms (infantile-, juvenile-, and adult-onset) of the disease are recognized. Patients with infantile GM1 gangliosidosis present at birth or shortly thereafter with somatic and bony changes, followed by severe neurological deterioration ultimately leading to death within the first 2 years of life. We present the brain CT, MRI and MR spectroscopy (MRS) findings in a 17-month-old Turkish girl with infantile GM1 gangliosidosis. Neuroimaging findings in patients with infantile GM1 gangliosidosis have been reported only in a few cases. In this study, MRS of the thalamus was performed to study the metabolic changes in GM1 gangliosidosis. We showed a a decreased NAA/Cr ration and an increased Cho/Cr ratio. To our knowledge, this is the first report of magnetic resonance spectroscopy findings in type-1 GM1 gangliosidosis.  相似文献   
109.
110.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号