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   464篇
  免费   22篇
  国内免费   37篇
耳鼻咽喉   14篇
儿科学   4篇
妇产科学   19篇
基础医学   39篇
口腔科学   5篇
临床医学   36篇
内科学   86篇
皮肤病学   3篇
神经病学   7篇
特种医学   10篇
外科学   93篇
综合类   49篇
预防医学   11篇
药学   27篇
中国医学   6篇
肿瘤学   114篇
  2023年   8篇
  2022年   23篇
  2021年   19篇
  2020年   17篇
  2019年   18篇
  2018年   21篇
  2017年   14篇
  2016年   19篇
  2015年   21篇
  2014年   30篇
  2013年   32篇
  2012年   34篇
  2011年   30篇
  2010年   17篇
  2009年   28篇
  2008年   33篇
  2007年   31篇
  2006年   24篇
  2005年   9篇
  2004年   11篇
  2003年   7篇
  2002年   6篇
  2001年   8篇
  2000年   2篇
  1999年   9篇
  1998年   4篇
  1997年   3篇
  1996年   6篇
  1995年   5篇
  1994年   4篇
  1993年   2篇
  1992年   6篇
  1991年   1篇
  1990年   2篇
  1989年   5篇
  1988年   4篇
  1986年   2篇
  1985年   1篇
  1983年   3篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1977年   1篇
排序方式: 共有523条查询结果,搜索用时 31 毫秒
1.
Background In cases of synchronous colorectal hepatic metastases, the primary colorectal cancer strongly influences on the metastases. Our treatment policy has been to conduct hepatic resection for the metastases at an interval of 3 months after colorectal resection. We examined the appropriateness of interval hepatic resection for synchronous hepatic metastasis. Materials and methods The subjects were 164 patients who underwent resection of hepatic metastasis of colorectal cancer (synchronous, 70 patients; metachronous, 94 patients). Background factors for hepatic metastasis and postoperative results were compared for synchronous and metachronous cases. Results The cumulative survival rate for 164 patients at 3, 5, and 10 years postoperatively was 71.9%, 51.8%, and 36.6%, and the post-resection recurrence rate in remnant livers was 26.8%. Interval resection for synchronous hepatic metastases was conducted in 49 cases after a mean interval of 131 days. No difference was seen in postoperative outcome between synchronous and metachronous cases. Conclusion The outcome was similarly favorable in cases of synchronous hepatic metastasis and in cases of metachronous metastasis. Delaying resection allows accurate understanding of the number and location of hepatic metastases, and is beneficial in determining candidates for surgery and in selecting surgical procedure.  相似文献   
2.
Staphylococcus aureus osteomyelitis and pyogenic arthritis has a different pattern in the elderly than in the young. The axial skeleton is the most frequent site of infection and treatment is usually by intravenous antibiotics. We report a case ofStaph. aureus septic arthritis of the elbow with concomitant osteomyelitis of the spine that was thought to be due toStaph. aureus, but culture of debrided material from the lesion grewBrucella in culture. We suggest that in the elderly it is advisable to obtain a tissue culture diagnosis and not to instigate therapy based on positive blood cultures or a concomitant infection.  相似文献   
3.
对心脑疾病人群的同步十二导联ECG(心电图)进行多重分形特性分析,发现不同导联的多重分形曲线互不重叠。计算其十二导联平均的多重分形奇异强度分布范围以及分布范围的十二个导联间的离散特性,发现不同人群中存在互为交叉而有明显不同的结果。用十二导联多重分形Δα的平均值Δα及其离散度δα(取Δα的标准差)两个参量来描述其多重分形谱特征。发现健康人与心脏病人Δα接近,但δα相差较大;健康人与脑损伤患者δα接近,但Δα相差较大。预示着多重分形特性受到神经自律和心脏组织结构的自谐特性的双重控制,特征参数Δα与神经控制相对应,δΔ与心脏组织结构自谐特性的各向异性相对应。  相似文献   
4.
Highly synchronised cultures of cloned Plasmodium falciparum (clone T9-94) were metabolically radiolabelled with [35S]methionine during eight consecutive non-overlapping intervals, while parasites developed from young rings to mature schizonts. Analysis of equal amounts of trichloroacetic acid precipitable radioactivity from each interval by sodium dodecyl sulphate-polyacrylamide gel electrophoresis fluorography allowed the stage specificity of protein synthesis to be investigated. More than forty polypeptides with molecular weights of 20 000 to 200 000 can be distinguished. While some proteins are synthesised throughout erythrocytic schizogony many are shown to be stage-specific. Among these are a range of high molecular weight proteins synthesised only during nuclear division. Detailed morphological information permits correlations to be made between synthesis of particular polypeptides and parasite structure.  相似文献   
5.
In acute experiments the sciatic nerve of the rat is electrically stimulated to induce fatigue in the medial Gastrocnemius muscle. Fatigue tests are carried out using intermittent stimulation of different compartments (sequential) or a single compartment (synchronous) of the sciatic nerve. The activation of different compartments is achieved by dividing nerve fibres into subbundles and placing them in separate grooves in a multigroove electrode. The aim of the investigation is to quantify the effect of sequential contra synchronised stimulation in reducing muscle fatigue, with no overlap between compartments. Overlap between two compartments is calculated using the combined and individual forces from both compartments. Sequential stimulation of two and three compartments is investigated. There is a significant decrease of fatigue in sequential stimulation compared to synchronous. After 2 min of intermittent stimulation the force time level is significantly increased in sequential stimulation, than in synchronous stimulation. The rate of force time decrease is significantly slower in sequential stimulation than in synchronous stimulation. With sequential stimulation it takes significantly longer before the maximal force time is reached than with synchronous stimulation.  相似文献   
6.
P. knowlesi parasites with a maximum age distribution of 3 h were metabolically labelled with [35S]methionine during 9 sequential non-overlapping intervals, from young rings to mature segmented schizonts. The proteins synthesised at the different stages were compared using sodium dodecyl sulphate-polyacrylamide gel electrophoresis; more than 40 polypeptides (Mr 20 000 to over 200 000) were identified in the different parasite preparations. The major polypeptides synthesised by rings and trophozoites of different ages were similar, but differences in minor polypeptides could always be recognised. At the onset of schizogony ring and trophozoite specific proteins ceased to be synthesised and proteins specific to schizogony emerged. In general, schizont-specific proteins were of higher molecular weight than ring stage proteins. Details of the morphological changes which occurred during the metabolic labelling episode permits correlation between parasite structure and synthesis of particular polypeptides. Comparison of parasite components metabolically labelled with [3H]glucosamine during defined periods of development also revealed stage-specific synthesis of glycoproteins. The extent to which proteins are altered after synthesis has been investigated by pulse-chase experiments.  相似文献   
7.
8.
双侧原发性乳腺癌的X线评价与临床对照研究   总被引:1,自引:0,他引:1  
目的:早期发现对侧乳腺癌。方法:搜集36例双侧原发性乳腺癌患者的临床、病理及X线资料进行对照分析。结果:(1)20例同时性乳腺癌中19例X线明确诊断双侧原发性乳腺癌。另1例一侧诊断乳腺癌,另一侧误诊为腺体增生。临床诊断双侧原发性乳腺癌8例,另12例未发现乳腺癌。(2)16例异时性乳腺癌中,后发癌中临床11例触及肿物,摄片诊断为乳腺癌;另5例临床未触及肿物,摄片发现乳腺癌。结论:(1)乳腺摄影有助于早期发现对侧原发乳腺癌。(2)临床触不到肿块就不会有癌存在的观念应该改变。(3)双侧乳腺应同时进行X线检查,有利于早期发现病灶。同时为以后对照比较提供资料。  相似文献   
9.
Fifteen percent to twenty-five percent of patients affected by colorectal cancer presents with liver metastases at diagnosis. In resectable cases, surgery is the only potentially curative treatment and achieves survival rates up to 50% at 5 years. Management is complex, as colorectal resection, liver resection, chemotherapy, and, in locally advanced mid/low rectal tumors, radiotherapy have to be integrated. Modern medical practice usually relies on evidence-based protocols. Levels of evidence for synchronous metastases are poor:published studies include few recent prospective series and several retrospective analyses collecting a limited number of patients across long periods of time. Data are difficult to be generalized and are mainly representative of single centre’s experience, biased by local recruitment, indications and surgical technique. In this context, surgeons have to renounce to "evidence-based medicine" and to adopt a sort of "experience-based medicine". Anyway, some suggestions are possible. Simultaneous colorectal and liver resection can be safely performed whenever minor hepatectomies are planned, while a case-by-case evaluation is mandatory in case of more complex procedures. Neoadjuvant chemotherapy is preferentially scheduled for patients with advanced metastatic tumors to assess disease biology and to control lesions. It can be safely performed with primarytumor in situ , even planning simultaneous resection at its end. Locally advanced mid/low rectal tumor represents a further indication to neoadjuvant therapies, even if treatment’s schedule is not yet standardized. In summary, several issues have to be solved, but every single HPB centre should define its proper strategy to optimize patient’s selection, disease control and safety and completeness of surgery.  相似文献   
10.
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