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   16506篇
  免费   753篇
  国内免费   68篇
耳鼻咽喉   87篇
儿科学   172篇
妇产科学   127篇
基础医学   2019篇
口腔科学   484篇
临床医学   1265篇
内科学   4177篇
皮肤病学   247篇
神经病学   1190篇
特种医学   568篇
外科学   3095篇
综合类   47篇
预防医学   433篇
眼科学   219篇
药学   1156篇
中国医学   21篇
肿瘤学   2020篇
  2023年   97篇
  2022年   171篇
  2021年   294篇
  2020年   151篇
  2019年   227篇
  2018年   246篇
  2017年   233篇
  2016年   256篇
  2015年   259篇
  2014年   326篇
  2013年   442篇
  2012年   679篇
  2011年   724篇
  2010年   418篇
  2009年   351篇
  2008年   671篇
  2007年   696篇
  2006年   740篇
  2005年   756篇
  2004年   741篇
  2003年   699篇
  2002年   730篇
  2001年   627篇
  2000年   657篇
  1999年   582篇
  1998年   251篇
  1997年   177篇
  1996年   147篇
  1995年   136篇
  1994年   128篇
  1993年   132篇
  1992年   528篇
  1991年   485篇
  1990年   442篇
  1989年   427篇
  1988年   340篇
  1987年   315篇
  1986年   302篇
  1985年   257篇
  1984年   167篇
  1983年   154篇
  1979年   137篇
  1978年   93篇
  1977年   78篇
  1975年   62篇
  1974年   85篇
  1973年   72篇
  1972年   79篇
  1971年   72篇
  1969年   64篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
21.
Exfoliative toxin D (ETD) was identified recently as a new exfoliative toxin serotype. Like other exfoliative toxins, ETD induces intra-epidermal cleavage through the granular layer of the epidermis of neonatal mice. The distribution of ETD production was investigated in Staphylococcus aureus isolates from infected and colonised patients in France. The etd gene was found in 55 (10.5%) of 522 isolates tested. Isolates responsible for bullous impetigo and generalised staphylococcal scalded skin syndrome did not harbour etd, but etd was significantly more frequent in isolates causing cutaneous abscesses and furuncles. Most etd- and Panton-Valentine leukocidin-positive strains belonged to the clone of community-acquired methicillin-resistant S. aureus spreading currently throughout France.  相似文献   
22.
Ryo Hattori  MD    Tateki Kubo  MD    Kenji Yano  MD  PhD    Atsushi Tanemura  MD    Yuji Yamaguchi  MD  PhD    Satoshi Itami  MD  PhD    Ko Hosokawa  MD  PhD 《Dermatologic surgery》2003,29(10):1071-1072
BACKGROUND: Nevus lipomatosus cutaneous superficialis (NLCS) is a relatively rare condition. Although NLCS can affect any region of the entire body, no case of NLCS in the clitoris has ever been reported. OBJECTIVE: To report a case of NLCS of the clitoris that presented manifestations that were similar to female pseudohermaphrodism. METHODS: This is a case report and review of the literature. RESULTS: A congenital, soft, skin-colored lesion of the clitoris in a 1-year-old girl resembled female pseudohermaphrodism. It was resected, and the histologic diagnosis was NLCS. Postoperatively, there was no subsequent change in the lesion during the 3-year follow-up period. CONCLUSION: We reported a case of congenital solitary NLCS of the clitoris. Although NLCS might be a relatively rare condition, we should consider it in the differential diagnosis of female pseudohermaphrodism.  相似文献   
23.
OBJECTIVE: The effect of tonicity changes in nebulizer solutions and irrigations on nasal mucosa is not well known. The present study aims to determine the basic mechanism of hypertonic solution on airway epithelial barrier. STUDY DESIGN AND SETTING: We investigated the electrical potential difference (PD) that is influenced by both active transport and the transepithelial electrical resistance of the epithelial mucosa in the human nose in vivo. The short circuit current (SCC) revealed net ion transport across the epithelium in the guinea pig trachea in vitro. Finally, the size dependency of macromolecules across the tracheal mucosa was determined in vitro using FITC-labeled dextrans of different sizes. RESULTS: PD was significantly decreased after topical application of hypertonic solution both in human and in guinea pig nose. SCC was significantly decreased after application of hypertonic solution. The transport of these dextrans from the basolateral to the apical side was not increased significantly after apical application of hypertonic saline. CONCLUSIONS: Hypertonic saline enhances the electrical permeability of the airway epithelial mucosa but not transport of macromolecule in the short term.  相似文献   
24.
Skull metastasis of thyroid carcinoma is rare. The majority of skull metastases of thyroid carcinoma are of the follicular subtype, rather than thyroid papillary carcinoma. In this report, a 55-year-old woman with skull metastasis from thyroid papillary carcinoma is presented. The metastatic lesion of the skull was hypervascular and osteolytic, and the bleeding was profuse during resection. There have been only four reports of skull metastasis from thyroid papillary carcinoma. The mean period from the initial diagnosis of thyroid carcinoma until the detection of skull metastasis is 23.3 years, whereas in this patient, it was about 2 years. Therefore, in the clinical course of thyroid papillary carcinoma, skull metastasis should be considered, and the patient should be meticulously followed up.  相似文献   
25.
A 71-year-old woman was admitted to our hospital by ambulance, because of right chest pain and hypotension. Chest X-ray and standard 12-lead ECG showed mirror-image dextrocardia with situs inversus totalis. ECG with right-left reversal of all leads showed acute inferior myocardial infarction. The patient underwent coronary bypass surgery due to postinfarction angina, and she is now doing well 2 years following the operation. Mirror-image dextrocardia with situs inversus totalis is very unusual. But the patients are believed to have normal longevity, and presumably have an incidence of atherosclerotic coronary artery disease similar to the general population. To our knowledge, this is the first case of coronary bypass surgery on a patient with mirror-image dextrocardia in Japan.  相似文献   
26.
We have obtained the good result about tricuspid annular constriction (TAC) for secondary tricuspid insufficiency. The purpose of this study is to investigate the effectiveness of TAC for the experimental model of tricuspid annular dilatation. First of all, tricuspid annular dilatation was made surgically in 8 mongrel dogs by placing 8 incisions to tricuspid annulus except septal cusp under the condition of heart-lung preparation. On clinical evaluation, septal annulus was kept to be intact in many cases compared with the two other areas. This experimental model of tricuspid annular dilatation was considered to be substituted to the clinical model of tricuspid annular dilatation. TAC suture was surrounded circumferentially around the dilated tricuspid annulus. And then, TAC suture was pulled out from the right atrial wall, and the circumferential length of tricuspid annulus was completely accommodated by pulling the TAC suture. The hemodynamic status was observed by right atrial pressure (V wave and mean) and right ventricular end-diastolic pressure (RVEDP). After heart resuscitation and gradual increase of preload, right atrial pressure was significantly elevated especially right atrial pressure (V wave) compared with control values. When 2 cm of circumferential length of tricuspid annulus on an average was constricted by shortening of TAC suture, right atrial pressure was significantly decreased, and then RVEDP tended to decrease. It was shown that TAC was an effective operative technique for the secondary tricuspid annular dilatation and tricuspid insufficiency from the standpoint of experimental aspect as well as clinical results.  相似文献   
27.
A 48-year-old woman was admitted because of increased bloody sputum. Since she had had a history of repeated thrombotic episodes including venous thrombosis in the lower limbs (21 year old) and pulmonary emboli developing into pulmonary infarction (41 years old), the patient was treated with anti-coagulant therapy using Warfarin for 7 years. Warfarin was discontinued after admission and heparin was administered instead at a relatively low dose of 5,000 units daily, resulting in a considerable diminution of hemoptysis. Unfortunately however, it caused a relapse of active thrombosis associated not only with a significant increase of the product of fibrinolysis (FDP), LDH and GOT but with a concomitant decrease of the platelet count. Hematological examinations concerning coagulation and fibrinolysis remained within a normal range except for the serum concentration of antithrombin III (AT III) and its functional property with regard to the heparin cofactor, which were 8.8 mg/dl and 48%, respectively. Since the findings were consistent with congenital deficiency of AT III, some members of her family were also examined. The concentration of AT III and its activity in the patient's son and her daughter deteriorated in a similar manner, indicating that this was a definite case of congenital deficiency of AT III. The clinical manifestations of 87 cases with congenital AT III deficiency, belonging to 24 families reported in Japan were reviewed.  相似文献   
28.
We implanted normal peripheral blood lymphocytes (PBL) from healthy donors and splenic tissues from patients with gastric cancers into the severe combined immunodeficient (SCID) mouse, demonstrating that SCID mouse with splenic tissue can produce a high level of human immunoglobulin G (IgG). The normal PBLs at 10(7) and 10(8)/mouse were implanted intraperitoneally, and three splenic tissues with a size of 3 x 3 x 3 mm from gastric cancer patients were inoculated subcutaneously into the bilateral backs of the mice. At 2, 4, 6 and 8 weeks after inoculation, mice were killed, and the human IgG was assessed by an ELISA method. SCID mice with splenic tissue revealed high human IgG levels from 2 weeks after inoculation and approximately 2 mg of IgG per ml was observed at 8 weeks post-implantation, while the IgG levels in mice treated with PBLs were limited. Since the half life of the extrinsic human IgG was 10.2 days, the high level of human IgG in the SCID mice was supposed to be produced by human plasma cells in the splenic tissue from gastric cancer patients. This model was thought to be adequate for evaluating human immunological functions in vivo.  相似文献   
29.
Subclinical gallbladder carcinoma.   总被引:7,自引:0,他引:7  
Clinicopathologic features of 31 patients with subclinical gallbladder carcinoma were reviewed in an attempt to determine the parameters for a course of therapy. Subclinical gallbladder carcinoma was defined as a gallbladder carcinoma that was first diagnosed microscopically by surgical pathologists. Of 31 patients, there were 26 women and 5 men, ranging in age from 54 to 84 years (mean age: 68 years). All 31 patients had undergone cholecystectomy for presumed benign gallbladder conditions. The 31 gallbladder carcinomas consisted of 6 carcinomas limited to the mucosa or the muscle coat (m or pm) and 25 carcinomas extending into the subserosal layer with surgical margins free of malignant cells in 14 (ss ew [-]) and affected by malignant cells in 11 (ss ew [+]). Cumulative 1-year, 3-year, and 5-year survival rates of six patients with m or pm carcinoma were 100% (p less than 0.001, versus ss ew [+] at 1 year), 100% (p less than 0.05, versus ss ew [-] at 3 years), and 100% (p less than 0.05, versus ss ew [-] at 5 years) compared with 91% (p less than 0.01, versus ss ew [+] at 1 year), 65%, and 65% of 14 with ss ew (-) carcinoma and 43%, 0%, and 0% of 11 with ss ew (+) carcinoma. Thirteen of the 31 patients died of local recurrence and/or liver metastasis. Univariate logrank analysis of 10 prognostic factors showed that depth of invasion, venous invasion, and surgical margin were prognostic factors. Multivariate Cox-regression analysis of these three profound factors demonstrated that surgical margin and depth of invasion were independent variables. These results showed that m or pm subclinical gallbladder carcinoma does not necessarily require an additional operation, whereas ss ew (-) and ss ew (+) carcinomas necessitate additional resection and adjuvant treatment.  相似文献   
30.
The effects of fenbufen on the serum concentrations and penetration into the brain and CSF of sparfloxacin (AT-4140), a new quinolone antibacterial agent, were investigated in rats. At designated times after a bolus iv dose of sparfloxacin 10 mg/kg with or without fenbufen 20 mg/kg, arterial blood, CSF and whole brain were simultaneously collected from each rat. Sparfloxacin concentrations were assayed by HPLC. Serum concentration of sparfloxacin declined bi-exponentially with time and was not changed by coadministered fenbufen. Binding sparfloxacin to serum protein slightly decreased after the coadministration. No elevation of sparfloxacin concentrations was observed in either brain or CSF after coadministration with fenbufen except for only a few time-points. The pharmacokinetic analysis based on the physiological model indicated that fenbufen did not affect the permeability across the blood-brain or blood-CSF barrier. These results suggest that fenbufen may be unlikely to affect the pharmacokinetics, involving the entry into the central nervous system, of sparfloxacin.  相似文献   
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