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   416篇
  免费   24篇
  国内免费   10篇
耳鼻咽喉   1篇
儿科学   32篇
妇产科学   1篇
基础医学   30篇
口腔科学   8篇
临床医学   43篇
内科学   57篇
皮肤病学   11篇
神经病学   7篇
特种医学   132篇
外科学   61篇
综合类   6篇
预防医学   26篇
药学   20篇
  1篇
肿瘤学   14篇
  2022年   1篇
  2021年   8篇
  2020年   4篇
  2019年   8篇
  2018年   7篇
  2017年   7篇
  2016年   3篇
  2015年   3篇
  2013年   9篇
  2012年   12篇
  2011年   7篇
  2010年   5篇
  2009年   10篇
  2008年   10篇
  2007年   18篇
  2006年   19篇
  2005年   6篇
  2004年   6篇
  2003年   7篇
  2002年   3篇
  2001年   8篇
  2000年   6篇
  1999年   12篇
  1998年   19篇
  1997年   15篇
  1996年   26篇
  1995年   15篇
  1994年   21篇
  1993年   17篇
  1992年   3篇
  1991年   6篇
  1990年   6篇
  1989年   18篇
  1988年   15篇
  1987年   19篇
  1986年   11篇
  1985年   10篇
  1984年   8篇
  1983年   12篇
  1982年   10篇
  1981年   9篇
  1980年   8篇
  1979年   5篇
  1978年   1篇
  1977年   6篇
  1976年   9篇
  1975年   2篇
排序方式: 共有450条查询结果,搜索用时 15 毫秒
61.
62.
63.
Between 1978 and 1981, 74 women with nonpalpable breast cancer underwent surgery after localization guides were placed. In 72 patients, guides were introduced parallel to the chest wall; in two the needle was positioned anteroposteriorly under computed tomographic guidance. Fifty-six cases (76%) were infiltrating cancer; 13 (17%), intraductal cancers; two (3%), inflammatory; and three (4%), lobular carcinoma in situ. Surgery was not used to treat the latter five patients. In the remaining 69 women, 42 (61%) were treated by means of modified radical mastectomy; six (9%), total mastectomy; 12 (17%), local excision and radiation therapy; and seven (10%), local excision alone; exact therapy for two women (3%) was unknown. At a minimum follow-up of 5 years, none of the 67 women in whom the parallel approach was used had a local recurrence. The authors conclude that preoperative placement of guides parallel to the chest wall does not appear to increase the risk of local breast cancer recurrence.  相似文献   
64.
Localized phosphorus-31 magnetic resonance (MR) spectroscopy in humans has previously been accomplished with surface coils by means of depth-resolved surface coil spectroscopy or rotating frame experiments, in which the extent of tissue sampled critically depends on surface coil placement. The authors' goal was to modify the surface coil image-selected in vivo spectroscopy (ISIS) experiment to accomplish three-dimensional volume selection through application of selective pulses in the presence of B0 gradients. Advantages of ISIS include the ability to use proton images to define the volume of interest (VOI) and reduced dependence on exact positioning of the surface coil. However, rapid replication of the surface coil ISIS experiment can cause spectral contamination from signals originating outside the VOI. A modified version of the ISIS experiment was developed to alleviate contamination under conditions of rapid replication. Applications of localized P-31 MR spectroscopy for observation of high-energy phosphorus metabolites are presented in human liver, heart, and transplanted and normal kidney.  相似文献   
65.
进一步研究了抗三尖杉酯碱的HL-60细胞(HR20)抗细胞凋亡的机制及该抗性和抗药性的关系。结果表明,环孢菌素A(CsA)20,10μg·ml-1诱导HL-60细胞发生凋亡,而阻断HR20细胞于G1期,就不能诱导细胞发生凋亡。低浓度的CsA明显增加柔红霉素在HR20细胞内的积聚,其逆转抗药性作用与阻断细胞周期运行无关。CsA10μg·ml-1处理HR20细胞,可引起50kDa的蛋白质高度磷酸化。结果提示:环孢菌素A阻断抗三尖杉酯碱的HL-60细胞于G1期,而诱导敏感的HL-60细胞发生凋亡,其阻断作用与抗药性无关。  相似文献   
66.
A prospective study was done of complications associated with 134 consecutive diagnostic spinal cord arteriograms in 96 patients (63 men and 33 women aged 17-78 years). Patients were examined for either arteriovenous malformation (n = 88) or tumor (n = 8), as indicated by myelography. Among the complications, 11 (8.2%) were local, five (3.7%) were systemic nonneurologic, and three (2.2%) were neurologic (two were associated with full recovery in less than 24 hours, and one was associated with full recovery in less than 1 week). No specific clinical or technical factors were significantly associated with the development of neurologic complications. Details of the clinical profile, angiographic technique, and pathologic findings for each patient were recorded and analyzed with respect to the potential risk for arteriographic complications. Diagnostic spinal cord arteriography had an acceptable risk within the range of other neuroangiographic diagnostic procedures.  相似文献   
67.
68.
A scanning equalization system for improved chest radiography   总被引:1,自引:0,他引:1  
Plewes  DB; Wandtke  JC 《Radiology》1982,142(3):765
  相似文献   
69.
Waanders E, Venselaar H, te Morsche RHM, de Koning DB, Kamath PS, Torres VE, Somlo S, Drenth JPH. Secondary and tertiary structure modeling reveals effects of novel mutations in polycystic liver disease genes PRKCSH and SEC63. Polycystic liver disease (PCLD) is characterized by intralobular bile duct cysts in the liver. It is caused by mutations in PRKCSH, encoding hepatocystin, and SEC63, encoding Sec63p. The main goals of this study were to screen for novel mutations and to analyze mutations for effects on protein structure and function. We screened 464 subjects including 76 probands by direct sequencing or conformation‐sensitive capillary electrophoresis. We analyzed the effects of all known and novel mutations using a combination of splice site recognition, evolutionary conservation, secondary and tertiary structure predictions, Poly Phen , and p Mut and sift . We identified a total of 26 novel mutations in PRKCSH (n = 14) and SEC63 (n = 12), including four splice site mutations, eight insertions/ deletions, six non‐sense mutations, and eight missense mutations. Out of 48 PCLD mutations, 13 were predicted to affect splicing. Most mutations were located in highly conserved regions and homology modeling for two domains of Sec63p showed severe effects of the residue substitutions. In conclusion, we identified 26 novel mutations associated with PCLD and we provide in silico analysis in order to delineate the role of these mutations.  相似文献   
70.
Objective: The causal link between obesity and endometrial cancer is well established; however obese women's knowledge of this relationship is unknown. Our objective was to explore patients' understanding of this relationship and assess the acceptability of a technology-based weight loss intervention. Methods/materials: Obese women with Type I endometrial cancer/hyperplasia were surveyed about their assessment of their body mass, knowledge of the relationship of obesity and endometrial cancer, and eating and activity habits. Interest in participation in an intervention also was assessed. Results: Eighty-one women with early stage (71.6% stage I) and grade (41.7% grade 1) disease completed the survey. The median BMI was 35.4 kg/m2 (IQR 32.2–43.5 kg/m2) and the average age was 59.3 (SD 11.1) yr. 76.25% of women were unable to categorize their BMI correctly and 86.9% of those incorrectly underestimated their BMI category. One-third (35.9%) were unaware of any association between obesity and endometrial cancer and 33.3% responded that obesity decreased or did not significantly increase the risk of endometrial cancer. 59% expressed interest in a weight loss intervention. Conclusions: Endometrial cancer survivors with obesity underestimated their obesity and lacked knowledge regarding the link between obesity and endometrial cancer. However, the majority expressed interest in electronically delivered weight loss interventions.  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