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   253515篇
  免费   33102篇
  国内免费   8435篇
耳鼻咽喉   1839篇
儿科学   3179篇
妇产科学   5546篇
基础医学   19973篇
口腔科学   3010篇
临床医学   22151篇
内科学   28309篇
皮肤病学   1814篇
神经病学   2546篇
特种医学   7845篇
外国民族医学   293篇
外科学   33364篇
综合类   33967篇
现状与发展   45篇
一般理论   3篇
预防医学   13805篇
眼科学   1370篇
药学   17816篇
  169篇
中国医学   6988篇
肿瘤学   91020篇
  2024年   878篇
  2023年   5401篇
  2022年   10259篇
  2021年   13606篇
  2020年   12615篇
  2019年   11458篇
  2018年   10896篇
  2017年   11476篇
  2016年   12270篇
  2015年   13903篇
  2014年   19953篇
  2013年   20125篇
  2012年   16118篇
  2011年   16483篇
  2010年   12269篇
  2009年   12373篇
  2008年   12590篇
  2007年   12118篇
  2006年   10635篇
  2005年   8918篇
  2004年   7377篇
  2003年   6137篇
  2002年   5201篇
  2001年   4689篇
  2000年   3894篇
  1999年   3307篇
  1998年   2803篇
  1997年   2493篇
  1996年   2074篇
  1995年   1865篇
  1994年   1580篇
  1993年   1271篇
  1992年   1141篇
  1991年   1038篇
  1990年   807篇
  1989年   703篇
  1988年   622篇
  1987年   537篇
  1986年   447篇
  1985年   558篇
  1984年   440篇
  1983年   305篇
  1982年   320篇
  1981年   286篇
  1980年   249篇
  1979年   172篇
  1978年   120篇
  1977年   90篇
  1976年   71篇
  1975年   59篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Background : A patient with a solitary pulmonary metastasis who had breast cancer in the past may benefit from pulmonary resection. Methods : Between 1984 and 1996, 17 patients underwent metastatectomy for metastatic breast cancer. There were 15 females and two males whose average age was 59 (range: 40–74 years). The median tumour-free interval after the primary breast-cancer operation was 5.1 years (range: 8 months-18.2 years). Sixteen patients had complete resections, which included six lobectomies and 10 lesser resections. Results : The postoperative mortality was nil and the morbidity rate was 6%. Follow-up was complete in all patients. Recurrent disease developed in four patients and two patients died of their disease. The 5-year survival was 62%. Conclusion : An aggressive surgical approach is warranted in patients with isolated resectable pulmonary metastases from breast cancer.  相似文献   
92.
Abstract: The optimal timing of systemic cyclophosphamide, methotrexate, 5-fluorouracil (CMF) chemotherapy and local radiation in adjuvant breast cancer has been a debatable subject. To evaluate the Lankenau Hospital experience with sequential CMF chemotherapy followed by radiation in the adjuvant therapy of stage I and stage II breast cancer we reviewed the records of patients at our center. This group of 34 patients was treated in a homogenous manner, all receiving standard CMF for six cycles followed by radiotherapy after lumpectomy with axillary lymph node dissection. The radiation course was 5040cGy to the entire breast (28 fractions in 45 elapsed days) followed by a boost to the tumor site of 1800cGy in 10 fractions. Thirty-four patients were identified and followed for an average of 5 years (range 1.5–11.5 years). One patient had local recurrence and with subsequent treatment is disease-free at 5 years postrecurrence (8 years from initial diagnosis). Two deaths were not breast-cancer related (1 myocardial infarction at year 3, 1 melanoma at year 7.5). The estimated probability of no relapse at 5 years and 8 years by Kaplan-Meier analysis is 79% and 60% respectively. Overall and disease-free survival in this group of patients treated with breast-conserving surgery and CMF chemotherapy followed by radiation is excellent. There appears to be no detriment to delaying radiotherapy until full doses of systemic treatment are given as local recurrence was rare (6%) and was amenable to further treatment.  相似文献   
93.
Comparison of the mutagenicity of nine isomeric benzo(a)pyrenyl [B(a)P] phenols conjugated with either sulfate or glucuronide was carried out using strain Salmonella typhimurium TA98. Of the nine conjugates tested, only B(a)P-1-sulfate was mutagenic. Accordingly, the mutagenicity of B(a)P-1-sulfate was compared with that of B(a)P and 1-hydroxybenzo(a)pyrene [B(a)P-1-OH] in the presence and absence of rat lung S9 and Aroclor-induced liver S9 with and without an NADPH-generating system. B(a)P-1-sulfate was slightly mutagenic, whereas B(a)P and the 1-hydroxy derivative were nonmutagenic when S9 fractions and NADPH were omitted. Addition of induced liver S9 with NADPH caused mutagenicity with B(a) -1-OH greater than B(a)P greater than B(a)P-1-sulfate. B(a)P-1-sulfate was the only mutagenic species when lung S9 was added. This mutagenicity did not require NADPH. Sodium sulfite, an inhibitor of arylsulfatase, decreased the mutagenicity of B(a)P-1-sulfate. These data suggest that a unique mutagenic species is generated from B(a)P-1-sulfate via arylsulfatase in rat lung.  相似文献   
94.
Abstract: Lobular carcinoma in situ (LCIS) has gone from a rare form of mammary cancer to a marker of increased risk. Treatment options have undergone a corresponding change from ipsilateral mastectomy with axillary node dissection to observation once it became clear that the majority of patients did not progress to invasive cancer. However, recent events suggest a re-evaluation of LCIS management options. It is clear that even meticulous observation may fail to detect invasive cancer before systemic spread has taken place. This fact plus the identification of breast cancer genes have brought a renewed interest in prophylactic mastectomy. At the same time pathologists feel that it is possible to identify microscopic features of LCIS pointing to an increased likelihood of developing invasive cancer. As a result physicians are being asked to better quantitate risks for individual patients. Most patients with LCIS do not need bilateral mastectomies, but we are coming closer to identifying the minority that would be better served by prophylactic surgery.  相似文献   
95.
总结我院12年来的12例肺血管瘤的资料,结合文献讨论了肺血管瘤的临床特点,如:女性多见,可有呼吸系统症状,X线多表现为孤立性病灶及生长缓慢等。准确诊断较难,手术治疗预后良好。应进一步加深临床对该病的认识。  相似文献   
96.
Primary dystonia is a disorder of movement for which no consistent pathophysiology has been identified; in the absence of evidence to the contrary, it is assumed to be cognitively benign. We have studied a clinically heterogeneous group of 14 patients with primary dystonia on a battery of neuropsychological tests. Despite well-preserved speed of information processing, language, spatial, memory and general intellectual skills relative to normal controls, we have identified a constellation of attentional-executive cognitive deficits on the Cambridge Neuropsychological Test Automated Battery (CANTAB). Specifically, patients demonstrated significant difficulties negotiating the extra-dimensional set-shifting phase of the IED task. The implications of these findings for the pathophysiology of primary dystonia are discussed. This is, to the best of our knowledge, the first report of a significant cognitive deficit in patients with primary dystonia.  相似文献   
97.
6例肺癌患者接受了大剂量卡铂并自体骨髓移植治疗 ,卡铂剂量从 5 60~ 1375 mg/ m2 ,5例加用 VP~ 1630 0 mg,1例并用 MMC6mg和 VCR2 mg;主要毒性反应为白细胞、中性粒细胞、血小板减少和脱发 ( WHO毒性反应 ~ 级 )其次是贫血、皮肤粘膜出血、呕吐和可逆性肝功能损害 ,口腔粘膜溃疡及轻度发烧各 2例 ,一过性蛋白尿、室上性心动过速和便秘各 1例 ,尿素氮和肌酐未见升高 ;全部患者骨髓均获解救 ,从自体骨髓回输到骨髓造血功能重建成功平均 2 6.67( 17~ 32 )天  相似文献   
98.
Early experience with laparoscopic abdominoperineal resection   总被引:4,自引:0,他引:4  
Background: Laparoscopic abdominoperineal resection (LAPR) has not been fully evaluated as a technique in the treatment of rectal and anal cancer or inflammatory bowel disease. The purpose of our study was to evaluate the early experience with laparoscopic abdominoperineal resection at Washington University Medical Center. Methods: A prospective analysis was performed on the first 21 patients undergoing the procedure at Washington University Medical Center. Indications for surgery included rectal cancer (14 patients), anal squamous cell cancer (four patients), inflammatory bowel disease (two patients), and anal melanoma (one patient). Results: The procedure was converted to open procedure in four patients (19%). The mean (±SEM) operative time and blood loss for completed and converted LAPR were 239 ± 11 min and 424 ± 43 ml, respectively. Postoperative hematocrit dropped a mean of 8.3% ± 1.2% SEM; five patients required blood transfusion (24%). Wound complication occurred in four patients (19%; three perineal, one trocar site). Bowel function returned after a mean of 3 days, and mean postoperative hospital stay for the completed LAPR group was 5 days. Mild pain was experienced by 81% of patients (17/21) while 19% (4/21) noted moderate pain, usually of the perineal wound. The mean duration of patient-controlled analgesia use was 2 days. During the 1–44-month follow-up, six patients (29%) died from cancer (stage III or IV at operation) and only one patient developed local recurrence in the pelvis (5%). There were no trocar-site implants of cancer. Furthermore, there was no relationship between prior abdominal operations, the amount of blood loss, postoperative drop of hematocrit, or blood transfusion requirement and the length of hospitalization or complication rates. Conclusion: Laparoscopic abdominoperineal resection is a feasible alternative to the conventional open technique in both cancer and colitis patients. Received: 23 April 1996/Accepted: 8 July 1996  相似文献   
99.
The role of open lung biopsy (OLB) in the diagnosis of the etiology of lung infiltrates in children was analyzed for a 10-year period 1979-1989 in a tertiary referral center. A total of 18 children had 19 lung biopsies to ascertain the cause of lung infiltrates. Thirteen of these children (72 %) were immunocompromised due to treatment of hematological/solid malignancies and bone marrow transplantation. The clinical diagnosis was bilateral lung infiltrates of unknown etiology in 17 of 18 children. Eight of these children were ventilated for respiratory failure. The biopsy was useful in achieving a histological diagnosis in 18 of 19 samples (diagnostic yield 95%) and an etiological diagnosis in 14 of 19 samples (etiological yield 74 %). Therapeutic strategy was altered in 14 of 18 patients based on the biopsy results. Five of 14 patients responded favorably to a change in specific treatment. The lime interval from onset of respiratory illness to biopsy was 2-60 days (mean 16 days). Despite the critical state of these children there were few complications associated with the biopsy and no mortality directly related to the procedure. We recommend that OLE be undertaken sooner rather than later in immunocompromised children with bilateral pulmonary infiltrates of unknown etiology.  相似文献   
100.
PURPOSE: The development of overall survival of a DOSAK (German-Austrian-Swiss Cooperative Group on tumours of the maxillofacial region) clinic's overall population comprising a time period of more than 20 years (1983-2004) should be assessed. At a cutoff date (January 1st, 1997), a change from a primarily surgically based to a consequent multi-modality treatment regimen was implemented. The periods of time before and after that change should be compared. METHODS AND PATIENTS: The data of the DOSAK registry entries on 1038 patients suffering from primary untreated oral and oropharyngeal carcinomas were updated with respect to follow-up and mortality data to achieve a 100% quality of follow-up. The end point (death) was reached in 67% of the overall population. Statistical analysis was carried out by the Trium Analysis Online corporation, Munich. RESULTS: The portion of female and older tumor patients increased, more than half of all tumor patients were clearly in stage IV of the disease at first referral. The portion of patients operated on persisted approximately (80%), the portion of additional treatment modalities could be increased considerably. The fact of a bony infiltration by the tumor and the operability remained highly significantly relevant for survival in multivariate analysis, despite of multi-modality treatment. The survival rate of the patients remained significantly dependent on the clinical stage of the disease in multivariate analysis but could be improved by 10% in the clinical stages II and III and in the patients who could not be operated on. All in all, the cutoff date was statistically relevant for survival in multivariate analysis, i.[Symbol: see text]e. the change in the treatment regimen had a verifiable positive effect on the survival of a unicentric overall population. CONCLUSION: Survival improvement in an overall population via change in treatment strategy is possible in relatively short time; the clinical stages II and III and the non-operable patients have the greatest benefit from a multi-modality treatment.  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