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   215篇
  免费   9篇
  国内免费   104篇
儿科学   5篇
妇产科学   4篇
基础医学   28篇
临床医学   81篇
内科学   41篇
皮肤病学   8篇
神经病学   4篇
特种医学   29篇
外科学   7篇
综合类   24篇
预防医学   7篇
眼科学   3篇
药学   71篇
肿瘤学   16篇
  2023年   1篇
  2022年   1篇
  2021年   3篇
  2020年   2篇
  2018年   3篇
  2017年   1篇
  2016年   1篇
  2015年   4篇
  2014年   3篇
  2013年   11篇
  2012年   1篇
  2011年   4篇
  2010年   5篇
  2009年   9篇
  2008年   5篇
  2007年   68篇
  2006年   6篇
  2005年   22篇
  2004年   1篇
  2003年   3篇
  2002年   5篇
  2001年   10篇
  2000年   11篇
  1999年   7篇
  1998年   13篇
  1997年   23篇
  1996年   12篇
  1995年   8篇
  1994年   6篇
  1993年   7篇
  1992年   8篇
  1991年   5篇
  1990年   7篇
  1989年   16篇
  1988年   10篇
  1987年   4篇
  1986年   4篇
  1985年   4篇
  1984年   3篇
  1983年   3篇
  1981年   1篇
  1980年   3篇
  1979年   1篇
  1971年   1篇
  1969年   1篇
  1968年   1篇
排序方式: 共有328条查询结果,搜索用时 187 毫秒
181.
β-受体阻断药在心血管病的治疗中占有相当重要的地位,对缺血性心脏病有肯定的疗效。但也存有不良反应或禁忌症,其中有的是由于其选择性不高所致。因此,寻找特异性的β_1受体阻断药是目前研究抗心肌缺血药的一个重要方面。据报道,在β-受体阻断药的基本有效结构的苯环的对位与4(3H)-喹唑酮环的2位  相似文献   
182.
Davis  SD; Berkmen  YM; Wang  JC 《Radiology》1990,177(1):127-131
To evaluate the radiographic manifestations of the response of intrathoracic metastases to and the toxicity of interleukin-2 (IL-2) therapy, the chest radiographs and computed tomographic scans of 43 patients receiving 103 cycles of IL-2 treatment and lymphokine-activated killer cells for advanced renal cell carcinoma were reviewed. Among these 43 patients, 31 could be assessed for response of metastatic disease: Complete response was seen in one (3%), partial response in 11 (36%), mixed response in nine (29%), progressive disease in five (16%), and stable disease in five (16%). In 103 treatment cycles radiographic evidence of toxicity included pleural effusions (45.6%), pulmonary edema (21.4%), increased cardiothoracic ratio (16.5%), increased azygos vein diameter (9.7%), pericardial effusion (5.8%), and hilar lymphadenopathy (1.0%). These toxic effects could be distinguished from metastatic disease by a temporal relationship to treatment cycles. A favorable response to IL-2 therapy was significantly correlated (P less than .001) with the presence of pleural effusions.  相似文献   
183.
大鼠心房肽Ⅲ及其小分子类似物的合成与生物活性   总被引:2,自引:0,他引:2  
以逐步合成法固相合成了大鼠心房肽Ⅲ(APⅢ)及22肽的小分子类似物。用无水氟化氢将肽从树脂上切下,同时脱除所有侧链保护基。还原产物在30%乙酸高度稀释下用碘作氧化剂,使分子内2个半胱氨酸氧化形成二硫键。经SephadexG-l5柱层析、透析和高效液相层析分离纯化,获得在反相高效液相层析(分析柱)为单一峰的高纯度产物。酸水解后氨基酸组成分析证实与理论值相符,生物活性测定表明,合成的APⅢ有强利尿、利尿钠、降血压和舒张血管乎滑肌作用。化学修饰后的小分子APⅢ类似物有APⅢ的全部生物活性,且作用时间延长。  相似文献   
184.
Twenty women underwent ultrasound examination three times during low-risk pregnancy. Before and after ultrasonography, the Symptom Questionnaire was applied to evaluate changes in psychological distress. Anxiety, depression, somatic symptoms, and hostility significantly decreased after the patients received video and verbal feedback during the first ultrasound examination. Such changes were consistently observed also during the subsequent two examinations.  相似文献   
185.
Among 1041 pregnancies 13 twin gestations were detected by routine ultrasonography prior to genetic amniocentesis at the Department of Prenatal Physiopathology of the University of Bologna. Clear amniotic fluid from both sacs was obtained in 12 of 13 sets of twins. All 12 sets were cytogenetically normal with normal levels of alpha-fetoprotein. Only one patient spontaneously aborted liveborn immature twins 30 days after the procedure. The technique used to obtain samples of fluid is described in detail and the need for additional counselling prior to amniocentesis in twins is stressed.  相似文献   
186.
The long term administration of a methyl donor (S-adenosylmethionine, SAM) relieves pain in migraine sufferers. The benefit arises gradually and long-term treatment is required for therapeutic effectiveness. Since SAM is an almost ubiquitous methyl donor in many biological systems, an explanation of this peculiar therapeutic effect is only speculative. The activity of SAM on 5-hydroxytryptamine turnover is the most reasonable interpretation of the results.  相似文献   
187.
This study was designed to assess the accuracy of knee MRI examinations carried out in a general tertiary referral hospital without a musculoskeletal fellowship trained radiologist. The study included all patients who had undergone a knee arthroscopy carried out within a 2‐year period and who had had a prior MRI knee examination, where both were carried out at this institution. The accuracy of the MRI knee examination was determined by correlation to the arthroscopy report. The accuracy for diagnosis of meniscal and cartilage injuries, in this setting, was found to be similar to a published meta‐analysis of previous studies correlating knee MRI and arthroscopy. The overall accuracy of this study was better than the previous similar study. However, the accuracy for diagnosing ACL injuries was lower than in the meta‐analysis. The potential reasons for this and other sources of error are discussed.  相似文献   
188.
A 20‐year old woman presented with acute right hemiplegia 10 weeks after intrauterine fetal death at 34‐weeks gestation (G1P0). A brain MRI showed a typical acute infarct in the left middle cerebral artery territory. A CT pulmonary angiography carried out 1 week later for sudden cardiopulmonary deterioration showed disseminated pulmonary metastases. The CT was extended to the abdomen and pelvis, which showed a uterine mass with bilateral theca lutein cysts. The radiological diagnosis of metastatic choriocarcinoma was made and was subsequently confirmed with the markedly increased serum β‐human chorionic gonadotrophin. A serum β‐human chorionic gonadotrophin is therefore considered worthwhile in any young female adult who presents with stroke.  相似文献   
189.
BACKGROUND: Soluble interleukin-2 receptor alpha (sIL-2R alpha) is a well-known indicator of T-cell activation noted to be increasing in nasopharyngeal cancer. However, the significance of sIL-2R alpha in monitoring disease relapse is unclear. This study was initiated to address this issue. METHODS: Serum of 56 patients with NPC, which underwent either primary, salvage, or palliative treatments, from 1992 to 1993 at the Cancer Center, Veterans General Hospital-Taipei, were collected from our serum bank. According to their disease status at the time of study, at least two years after last treatments, the 56 patients were divided into four groups. The remission group represented those in remission at the time of study (n = 24). The metastasis group represented those with distant metastasis present at the time of study (n = 17). The recurrence group represented those with locoregional recurrence present at the time of study (n = 11). The combined group represented those with locoregional recurrence as well as distant metastasis (n = 4). The seral sIL-2R alpha concentrations of the 56 NPC patients were determined with enzyme-linked immunoabsorbent assay. The combined group was excluded in our statistical analysis. We performed statistical analysis on the differences of paired serum sIL-2R alpha concentrations between different periods of the diseases. The first analysis was on the differences of sIL-2R alpha concentrations between diagnosis and post-radiotherapy periods for 13 out of 24 patients in the remission group and 7 out of 11 patients in the recurrence group. The second analysis was on the differences of sIL-2R alpha concentration between follow-up before detection-of-relapse and after detection-of-relapse for 5 out of 17 patients in the metastasis group and six out of 11 patients in the recurrence group. RESULTS: The first statistical analysis revealed no significant differences of sIL-2R alpha concentrations for the remission group (P = 0.946) and the recurrence group (P = 0.156) between diagnosis and post-radiotherapy periods. The second statistical analysis revealed no significant differences of sIL-2R alpha concentrations between before and after detection-of-relapse for the recurrence group, neither (P = 0.438). The results for the metastasis group were different. The sIL-2R alpha concentrations were shown to increase after the detection of metastasis for the 5 paired samples from the metastasis group, although the Wilcoxon signed ranks test on the differences only showed borderline significance (P = 0.063). CONCLUSIONS: Our findings show that sIL-2R alpha would be of no value in monitoring the development of locoregional recurrence but might be useful in monitoring distant metastasis. Although our current limited data did not provide strong support for the role of sIL-2R alpha in monitoring metastasis, it might be delineated in the future by collecting more data.   相似文献   
190.
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