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   17151篇
  免费   827篇
  国内免费   250篇
耳鼻咽喉   182篇
儿科学   238篇
妇产科学   103篇
基础医学   2701篇
口腔科学   325篇
临床医学   1639篇
内科学   1499篇
皮肤病学   1827篇
神经病学   694篇
特种医学   814篇
外科学   2409篇
综合类   1588篇
预防医学   1208篇
眼科学   72篇
药学   1861篇
  9篇
中国医学   595篇
肿瘤学   464篇
  2024年   71篇
  2023年   343篇
  2022年   638篇
  2021年   775篇
  2020年   527篇
  2019年   490篇
  2018年   466篇
  2017年   475篇
  2016年   459篇
  2015年   531篇
  2014年   997篇
  2013年   1120篇
  2012年   840篇
  2011年   998篇
  2010年   799篇
  2009年   697篇
  2008年   781篇
  2007年   676篇
  2006年   580篇
  2005年   557篇
  2004年   496篇
  2003年   401篇
  2002年   353篇
  2001年   333篇
  2000年   295篇
  1999年   252篇
  1998年   264篇
  1997年   233篇
  1996年   237篇
  1995年   241篇
  1994年   188篇
  1993年   175篇
  1992年   160篇
  1991年   136篇
  1990年   114篇
  1989年   108篇
  1988年   116篇
  1987年   106篇
  1986年   92篇
  1985年   126篇
  1984年   129篇
  1983年   80篇
  1982年   96篇
  1981年   102篇
  1980年   84篇
  1979年   97篇
  1978年   66篇
  1977年   60篇
  1976年   65篇
  1975年   39篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Dupuytren’s disease with severe finger contractures and recurrent contractures following previous surgery often have extensive skin involvement. In these severe cases, excision of the diseased chord along with the involved skin is a good option to reduce the risk of recurrance. The resulting skin defect can be covered with a full thickness skin graft (FTSG) or a cross finger flap. Cross finger flaps have donor finger morbidity and hence a full thickness graft is usually preferred. The FTSG extending to the midlateral margins on both sides of the finger reduces the risk of joint contracture due to graft shrinkage. Once the FTSG is sutured in place, the standard practice is to compress and secure the graft to its recipient bed with a tie-over dressing and this can be time consuming. We present a simple dressing technique to secure the FTSG without the need for a tie-over dressing.  相似文献   
2.
BACKGROUND/AIMS: The purpose of this work was to develop a new sensor for objective in vivo measurement of the cutaneous temperature based on micro-electro-mechanical systems (MEMS), and to compare these performances with those of a classical thermocouple. Research on this new sensor was carried out to allow the quantification of the thermal properties of the made-up skin. METHODS: Sixteen female subjects divided into two different age groups (18-35 and >50 years old) were recruited for this study. Several zones of the face and forearms were made up at random with foundations containing or not a thermoregulator raw material. The quantity of foundation applied on the skin was standardized and measurements were carried out first before make-up, and then 10 s and 5 min after make-up. The new sensor and the thermocouple were used successively on each zone. The cutaneous temperature was expressed in degrees celsius. RESULTS/CONCLUSION: The two systems are similar in terms of repeatability and reproducibility, with some differences in sensibility. The data measured by the MEMS sensor appear lower than those measured by the thermocouple. After make-up, the MEMS sensor detects a progressive increase of the temperature in time whereas the thermocouple detects a decrease. We found the same evolution on the face but in a more attenuated way. These results tend to show that the devices do not measure the same phenomenon. The thermocouple appears more sensitive to the thermal response of the made-up surface whereas the MEMS sensor appears more sensitive to the heat transfers in the interface between the skin and make-up.  相似文献   
3.
Vacuum-assisted closure (VAC), although a modern adjunct in wound management, has not been used previously in pyoderma gangrenosum (PG), probably to avoid the potential complications of ‘pathergy’. We would like to report our experience of VAC in three cases of PG with the relevant review of literature.  相似文献   
4.
The antiproliferative, cytotoxic and apoptogenic activities of Bufo melanostictus (Indian common toad) skin extract (TSE) on U937 and K562 leukemic cell line has been investigated. TSE significantly (P<0.001) reduced the time-dependent cell proliferation and decreased MTT values in U937 and K562 cells. TSE (IC50 doses) suppressed the proliferating cell nuclear antigen expression in both the cells. It was demonstrated that, TSE (IC50 doses) primarily arrested the U937 and K562 cells at G1 phase of the cell cycle. Confocal microscopy showed the altered fragmented nuclei and apoptotic bodies formation in TSE (IC50 doses) treated U937 and K562 cells. Membrane blebbing, cell surface shrinkage and perforation were observed through scanning electron microscope. TSE-induced DNA fragmentation in U937 and K562 cells was reflected in single-cell gel electrophoresis. TSE significantly (P<0.001) increase the length-width ratio of DNA mass as compared to control in comet assay. The flow cytometric analysis of annexin-V binding to the cancer cells further supported the apoptotogenic activity of TSE. The effect of TSE on normal human peripheral blood mononuclear cells viability and cytotoxicity was studied in culture and found to be less cytotoxic than on the U937 and K562 cells. The findings from the present study suggested that TSE might possess potent antineoplastic agent having antiproliferative, cytotoxic and apoptogenic activity against U937 and K562 myeloid leukemic cells.  相似文献   
5.
组织工程化表皮膜片构建及其在供皮区的应用研究   总被引:2,自引:0,他引:2  
目的构建组织工程化表皮细胞膜片并应用于供皮区创面治疗。方法利用患者少量自体或同种异体正常皮肤分离、培养、扩增的表皮细胞,接种于壳聚糖明胶膜构建成表皮细胞膜片;将膜片移植于治疗组供皮区创面、适度加压,同时设立对照组:空白材料对照以及传统油纱布对照覆盖创面。于术后5~10d、30d、90d行大体观察、组织学检查、广谱角蛋白、外皮蛋白、层粘连蛋白、免疫组织化学检测以及Ⅰ、Ⅲ型胶原比值测定(偏光显微镜、RTPCR)。结果利用自体及异体表皮细胞和壳聚糖明胶膜能够构建出人表皮细胞膜片,应用于临床供皮区创面治疗15例,经过3个月随访,疗效肯定。移植膜片创面愈合时间(8.1±1.3)d,空白材料对照区为(16.2±3.8)d,空白油纱布对照区为(23.0±5.8)d。移植膜片存活良好,结构较完整、术后30d及90d观察:12例无明显增生,3例有轻度增生(20.0%),而空白油纱布对照区11例遗留增生性瘢痕(74.4%,χ2=8.127,P<0.01)。结论表皮细胞-壳聚糖明胶膜片能促进供皮区创面早期愈合并减少后期瘢痕增生,具有良好治疗效果。  相似文献   
6.
术中即时扩张皮肤面积增加与压力和时间的量效关系   总被引:1,自引:1,他引:0  
目的探讨术中即时扩张皮肤面积增加与压力、时间的量效关系。方法用6头小型猪,压力参数分别为15、20、25kPa,时间参数为60、90min,配对组成6个实验组,1个对照组,36个实验部位。在每只猪背部皮下均匀埋置100ml圆形扩张器6个,术中即时扩张皮肤,观察扩张皮肤各径线移位特点,计算面积变化。结果扩张区周边皮肤向中心蠕动和扩张器表面皮肤伸展同时存在。扩张皮肤面积扩大在一定范围内与压力、时间增加成正比,20kPa、60min组合增幅最大,此后增幅明显减少,并逐渐引发皮肤病理性改变。结论皮肤可在一定范围内通过术中即时扩张获得面积有效增加。  相似文献   
7.
邻近皮瓣修复面部皮肤缺损   总被引:1,自引:0,他引:1  
目的 探讨邻近皮瓣修复面部皮肤缺损的应用效果。方法 162例面部病变切除后皮肤缺损患者,其中先天性色素痣63例,基底细胞癌28例,鳞状细胞癌6例,其他皮肤病变65例。均采用邻近皮瓣即时修复,其中菱形皮瓣57例、双叶皮瓣8例,A-T皮瓣23例、V-Y皮瓣13例、Z成形术23例、推进皮瓣27例、鼻状皮瓣11例。结果 162例皮瓣存活良好,手术切口1期愈合,存活后皮瓣颜色与邻近部位无明显差异,术后无眼睑、眉毛、鼻梁及口角牵扯歪钭,术后3个月切口不显露。结论 邻近皮瓣是修复面部较大皮肤缺损的良好方法,手术外观效果好。  相似文献   
8.
The application of spin-echo magnetic resonance imaging sequences on non-invasive temperature imaging for temperature mapping of human limbs is investigated. In an in vitro expriment performed on a meat sample, the equilibrium magnetisation P and the spin-lattice relaxation time T1 are calculated from the values for the repetition time TR and the signal intensities obtained by a spin-echo sequence at different tissue temperatures tures as measured by a fibre-optic probe. T1 is linearly correlated to the tissue temperature, and P is linearly correlated to the reciprocal value of the absolute temperature. Both effects, taken together, lead to a non-linear dependency of the signal intensity on temperature. Therefore a TR leading to maximum temperature dependency of the signal intensity is calculated and used in the futher experiments. In the in vivo experiments, the lower legs of two volunteers are cooled from outside. Images are acquired with a spin-echo sequence (1.5T, TR=1200 ms, TE=10 ms). A rise in signal intensity in the muscle with falling skin temperature is observed, particularly in more peripheral muscle layers. This study shows that spin-echo sequences can be used to monitor temperature changes and temperature differences in living muscle tissue.  相似文献   
9.
10.
甲基强的松龙对低温保存大鼠肝脏的保护作用   总被引:2,自引:1,他引:1  
应用Wistar大鼠肝脏离体灌流模型,用CMU—1号液,含有甲基强的松龙的CMU—1号液,以及缺血前预用甲基强的松龙后再用CMU—1号液分别对肝脏进行灌洗保存。检测LDH、ALT、肝组织匀浆SOD活性和MDA含量,并观察肝组织结构。结果表明:甲基强的松龙对低温保存的离体大鼠肝脏具有保护作用  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