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   994381篇
  免费   76797篇
  国内免费   2609篇
耳鼻咽喉   12977篇
儿科学   34464篇
妇产科学   28470篇
基础医学   145116篇
口腔科学   27737篇
临床医学   90027篇
内科学   192858篇
皮肤病学   22905篇
神经病学   79053篇
特种医学   38389篇
外国民族医学   305篇
外科学   149450篇
综合类   23709篇
一般理论   385篇
预防医学   77522篇
眼科学   22603篇
药学   71918篇
  3篇
中国医学   2030篇
肿瘤学   53866篇
  2018年   10596篇
  2017年   8260篇
  2016年   9397篇
  2015年   10629篇
  2014年   14446篇
  2013年   22043篇
  2012年   29064篇
  2011年   30919篇
  2010年   18537篇
  2009年   17476篇
  2008年   28852篇
  2007年   30508篇
  2006年   31003篇
  2005年   29676篇
  2004年   28953篇
  2003年   27832篇
  2002年   26842篇
  2001年   46934篇
  2000年   48044篇
  1999年   40273篇
  1998年   11181篇
  1997年   10099篇
  1996年   10162篇
  1995年   9776篇
  1994年   9092篇
  1993年   8480篇
  1992年   32204篇
  1991年   31452篇
  1990年   30999篇
  1989年   29860篇
  1988年   27155篇
  1987年   27325篇
  1986年   25407篇
  1985年   24590篇
  1984年   18371篇
  1983年   15464篇
  1982年   9250篇
  1981年   8332篇
  1979年   16824篇
  1978年   12191篇
  1977年   10283篇
  1976年   9720篇
  1975年   10154篇
  1974年   12299篇
  1973年   11828篇
  1972年   10879篇
  1971年   10105篇
  1970年   9371篇
  1969年   8714篇
  1968年   8094篇
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
71.
72.
Contrast‐enhanced spectral mammography (CESM) has a number of uses including the work‐up of inconclusive findings on mammography, assessment of breast symptoms, cancer staging, evaluation of response to neoadjuvant chemotherapy and recently as an alternative to magnetic resonance imaging (MRI) in high‐risk screening. CESM can be swiftly incorporated into the workflow of busy breast clinics. We share our experiences with CESM at a large breast assessment centre in Western Australia.  相似文献   
73.
Hypertrophic lichen planus (HLP) is a T‐cell‐mediated process typically presenting with hypertrophic or verrucous plaques on the lower limbs. We report the case of a 24‐year‐old woman with a history of HLP since age 3 years presenting with rapid malignant transformation of one lesion into a large squamous cell carcinoma (SCC). Subsequent examination revealed progressive, widespread metastatic involvement, and the patient ultimately died from her disease. SCC associated with HLP is rare, with a review of the literature revealing fewer than 50 cases. This case highlights the need to be aware of suspicious changes in HLP and to educate patients as to when to be reevaluated.  相似文献   
74.
75.
PurposeOur purpose was to determine the effect of chemoradiotherapy (CRT) on patient-reported quality of life (QOL) for patients with intact pancreas cancer.Methods and MaterialsWe reviewed a prospective QOL registry for patients with intact, clinically localized pancreatic ductal adenocarcinoma treated with CRT between June 2015 and November 2018. QOL was assessed pre-CRT (immediately before CRT, after neoadjuvant chemotherapy) and at the completion of CRT with the Functional Assessment of Cancer Therapy-Hepatobiliary (FACT-Hep) and its component parts: FACT-General (FACT-G) and hepatobiliary cancer subscore (HCS). A minimally important difference from pre-CRT was defined as ≥ 6, 5, and 8 points for FACT-G, HCS, and FACT-Hep, respectively.ResultsOf 157 patients who underwent CRT, 100 completed both pre- and post-CRT surveys and were included in the primary analysis. Median age at diagnosis was 65 years (range, 23-90). National Comprehensive Cancer Network resectability status was resectable (3%), borderline resectable (40%), or locally advanced (57%). Folinic acid, 5-fluorouracil, irinotecan, and oxaliplatin (FOLFIRINOX) (75%) or gemcitabine and nab-paclitaxel (42%) were given for a median of 6 cycles (range, 0-42) before CRT. Radiation therapy techniques included 3-dimensional conformal (22%), intensity modulated photon (55%), and intensity modulated proton (23%) radiation therapy to a median dose of 50 Gy (range, 36-62.5). Concurrent chemotherapy was most commonly capecitabine (82%). Sixty-three patients (63%) had surgery after CRT. The mean decline in FACT-G, HCS subscale, and FACT-Hep from pre- to post-CRT was 3.5 (standard deviation [SD], 13.7), 1.7 (SD 7.8), and 5.2 (SD 19.4), respectively. Each of these changes were statistically significant, but did not meet the minimally important difference threshold. Pancreatic head tumor location was associated with decline in FACT-Hep. Nausea was the toxicity with the greatest increase from pre- to post-CRT by both physician-assessment and patient-reported QOL.ConclusionsFor patients with intact pancreatic adenocarcinoma, modern CRT is well tolerated with minimal decline in QOL during treatment.  相似文献   
76.
77.
BackgroundCervical spondylodiscitis is a rare but severe complication of pharyngeal surgery.Material and methodsThis multicenter retrospective study reported all patients in the database of the French head and neck tumor study group (GETTEC) affected by cervical spondylodiscitis after transoral robotic surgery (TORS) for malignant pharyngeal tumor from January 2010 to January 2017.ObjectivesTo describe cases of post-TORS cervical spondylodiscitis, identify alarm signs, and determine optimal management of these potentially lethal complications.ResultsSeven patients from 6 centers were included. Carcinomas were located in the posterior pharyngeal wall. Tumor stage was T1 or T2. All patients had risk factors for spondylodiscitis. Mean time to diagnosis was 12.6 days. The interval between surgery and spondylodiscitis diagnosis ranged from 20 days to 4.5 months, for a mean 2.1 months. The most common symptom was neck pain (87%). Infections were polymicrobial; micro-organisms were isolated in 5 cases and managed by intravenous antibiotics, associated to medullary decompression surgery in 3 cases. Follow-up found favorable progression in 4 cases, and 3 deaths (mortality, 43%).ConclusionThis French multicenter study found elevated mortality in post-TORS spondylodiscitis, even in case of limited resection. Surgeons must be aware of this complication and alerted by persistent neck pain, fever, asthenia, impaired or delayed posterior pharyngeal wall wound healing or elevation of inflammatory markers. MRI is the most effective diagnostic radiological examination.  相似文献   
78.
We report a case of intestinal obstruction in a 73-year-old woman caused by ileocolic intussusception. The underlying cause was a giant submucosal ulcerating lipoma (6?×?3.3?×?3.8 cm) extending from the superior mucosal lip of Bauhin’s valve. Abdominal ultrasonography showed a pathognomonic target-like mass appearing as multiple concentric rings. CT scan confirmed the diagnosis. Because of apparent obstruction, a laparotomy with right hemicolectomy and ileocolic anastomosis was performed. Lipomas most frequently occur in the cecum and ascending colon where they represent the most common submucosal mesenchymal tumor. They typically occur in elderly women with an incidence that varies from 0.15 to 0.56 %. Pain, rectal bleeding, and obstruction are typical symptoms. When faced with an intussusception in children, reduction with air per rectum can be performed. In adults, however, malignant cell spreading and seeding is of big concern. Since approximately 20–50 % of all underlying causes are malignant, explorative surgery is favored in adults.  相似文献   
79.
80.
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