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   5146篇
  免费   478篇
  国内免费   318篇
耳鼻咽喉   151篇
儿科学   55篇
妇产科学   87篇
基础医学   609篇
口腔科学   69篇
临床医学   682篇
内科学   661篇
皮肤病学   71篇
神经病学   220篇
特种医学   199篇
外国民族医学   3篇
外科学   497篇
综合类   937篇
一般理论   1篇
预防医学   385篇
眼科学   108篇
药学   569篇
  11篇
中国医学   312篇
肿瘤学   315篇
  2024年   18篇
  2023年   74篇
  2022年   256篇
  2021年   321篇
  2020年   262篇
  2019年   179篇
  2018年   173篇
  2017年   176篇
  2016年   149篇
  2015年   274篇
  2014年   281篇
  2013年   296篇
  2012年   425篇
  2011年   467篇
  2010年   322篇
  2009年   233篇
  2008年   246篇
  2007年   211篇
  2006年   197篇
  2005年   198篇
  2004年   163篇
  2003年   142篇
  2002年   131篇
  2001年   90篇
  2000年   80篇
  1999年   98篇
  1998年   55篇
  1997年   58篇
  1996年   40篇
  1995年   42篇
  1994年   28篇
  1993年   19篇
  1992年   28篇
  1991年   26篇
  1990年   27篇
  1989年   25篇
  1988年   15篇
  1987年   15篇
  1986年   17篇
  1985年   7篇
  1984年   7篇
  1983年   8篇
  1980年   4篇
  1979年   5篇
  1976年   4篇
  1975年   7篇
  1973年   4篇
  1972年   7篇
  1971年   7篇
  1967年   3篇
排序方式: 共有5942条查询结果,搜索用时 15 毫秒
1.
小切口股骨近端解剖钢板治疗股骨转子间骨折   总被引:5,自引:4,他引:1  
目的 探讨股骨转子间骨折的治疗方法和疗效。方法小切口微创股骨近端解剖钢板内固定治疗股骨转子间骨折17例。结果 随访时间8个月~3年,平均1.6年,优良16例,占94%(16/17)。结论 小切口微创股骨近端解剖钢板内固定治疗股骨转子间骨折具有切口小、出血少等优点,是一种微创手术。  相似文献   
2.
脊髓手术中体感诱发电位监测的临床研究   总被引:3,自引:0,他引:3  
报告30例脊髓手术中体感诱发电位(SEP)连续监测的临床研究结果。SEP记录包括脊髓SEP(SSEP)和皮层SEP(SCEP)。麻醉药物对SEP有一定程度影响,SCEP相对较大。认为,至少术中SEP潜伏期延长不超过8%和波幅降低不超过50%,不会引起术后并发症,超过该范围由于病例较少,尚不能肯定与预后的关系,需进一步探讨。  相似文献   
3.
4.
In vivo 19F NMR at 4.7 T has shown that the biphasic elimination of the vapor anesthetic isoflurane from rat brain is ca 15% slower in old (23-24 months) animals compared with young (5-6 months) animals. The fast kinetic component has a t1/2 of ca 7-9 min and the slow event, 100-115 min. Gas chromatographic measurement of arterial blood elimination displays age attenuation to the same extent, although a monophasic kinetic process (6-7 min). The slow wash-out from brain is thought to involve elimination from intracranial fatty tissue as postulated by others in rabbit brain. Longitudinal relaxation time measurements show monoexponential recovery and essentially identical values for young (1.09 + 0.11 s) and old (1.04 +/- 0.09 s) animals. For dipalmitoylphosphatidylcholine vesicles the monoexponential recovery also suggests rapidly exchanging averaged homogeneous lipid environments for the anesthetic, but the longer T1s (2.75 +/- 0.25 s) imply less restricted mobility compared with brain. Single T2 values were obtained in vivo, indicating either a single compartment or rapid exchange between multiple environments. These measurements were inconsistent, undoubtedly as a result of B1 inhomogeneity. The age-attenuated elimination kinetics for isoflurane are consistent with poorer cardiopulmonary function, whereas the T1 data suggest similar environments for the anesthetic in young and old brain tissue.  相似文献   
5.
6.
目的 分析卒中高危人群糖化血红蛋白与颈动脉粥样硬化斑块的关系。
方法 2018年5-6月由孝感市中心医院按整群随机抽样方法,随机抽取孝感市城乡各1个社区居民
进行筛查,通过问卷调查、体格检查、实验室检查、颈部血管超声检查筛选卒中高危人群纳入研究。
根据颈动脉超声检测结果将卒中高危人群分为非斑块组和斑块组(颈动脉)。分别采用单因素和多
因素Logistic回归,分析糖化血红蛋白与颈动脉斑块的关系,并根据年龄(60岁)、BM(I 24 kg/m2)、是
否有高血压对研究人群进行分层分析,研究不同特征的卒中高危人群中糖化血红蛋白与颈动脉斑块
的关系。
结果 最终纳入卒中高危人群629例,男性338例(53.74%),平均54.85±8.97岁,糖化血红蛋白平
均浓度为4.70%±1.02%。其中斑块组患者215例(34.18%),非斑块组患者414例(65.82%)。与非斑
块组患者相比,斑块组患者男性、卒中、TIA、高血压、超重患者比例更高,年龄更大,BMI、血压、空
腹血糖、糖化血红蛋白、TC水平更高(均P<0.01)。校正其他危险因素后,糖化血红蛋白是颈动脉
粥样硬化斑块发生的独立影响因素(每升高1%,OR 1.16,95%CI 1.01~1.31,P =0.018)。分层分析显
示,年龄≥60岁(OR 1.48,95%CI 1.09~2.01,P =0.016)、BMI≥24 kg/m2(OR 1.97,95%CI 1.07~3.64,
P =0.030)、高血压人群(OR 1.31,95%CI 1.06~1.62,P =0.013)中糖化血红蛋白均是颈动脉斑块发生
的独立危险因素。
结论 卒中高危人群糖化血红蛋白与颈动脉斑块的发生密切相关,特别是在年龄≥6 0岁、
BMI≥24 kg/m2和高血压人群中。  相似文献   
7.
We have constructed cDNA microarrays from the human testis large insert cDNA library, containing 9216 genes, together with several housekeeping genes. The cDNA microarrays were used to identify gene expression differences between human fetal and adult testes. Of >8700 hybridized clones, 731 exhibited significant differential expression characteristics. About 7500 genes were identified when the same cDNA microarrays were used for hybridization with cDNA probes from mouse testis, with 256 genes having significant differential expression between the age of 1-4 weeks. Among these genes, 101 were identified as critically related to testis development and possibly to spermatogenesis since they were found in both human and mouse testes, and expressed differentially at different stages of testis development. Of the 101 development-related genes, 59 full-length cDNAs have been sequenced previously, while the full-length cDNAs of the other 42 genes have not been published. We have obtained 11 full-length sequences of the 42 genes and deposited them in the GenBank. The conserved testis development-related genes found in both human and mouse testes may include genes that are likely to be involved in testicular functions, especially spermatogenesis, thus providing a basis for further functional characterization of the genes in mouse models.  相似文献   
8.
In this study, a human adult testis cDNA microarray was constructed and hybridized with (33)P-labeled human adult testis, embryo testis and sperm cDNA probes, respectively. A novel alternative splice variant of BRDT gene, named BRDT-NY, presumably involved in testicular function was cloned. It was expressed 3.96-fold more in human adult than embryo testis and also expressed in human spermatozoa. Similarly, RT-PCR revealed a differential expression pattern of this gene in human adult testes and fetal testes. The full length of BRDT-NY was 3438 bp and contained a 2883 bp open reading frame, encoding a 960-amino-acid protein. Sequence analysis showed that it has two bromodomains in N-terminal of the protein. Multiple tissue RT-PCR results showed that BRDT-NY was exclusively expressed in testis. mRNA expression of BRDT-NY gene was deleted in some azoospermic patients' testes. These experiments suggested that BRDT-NY gene may have an important role in the process of spermatogenesis and may be correlated with male infertility.  相似文献   
9.
BackgroundPartial nephrectomy or angioembolisation is commonly used for sporadic renal angiomyolipomas (RAMLs) with high RENAL scores, but there is a risk of reduced renal function, postoperative complications, and recurrence.ObjectiveTo describe a new technique for off-clamp laparoscopic evacuation of sporadic RAMLs with high RENAL scores that promotes maximal renal function maintenance and low postoperative complication and lesion recurrence rates.Design, setting, and participantsA retrospective cohort of patients undergoing off-clamp laparoscopic evacuation for sporadic RAMLs with RENAL scores ≥9 from January 2013 to June 2018 was included.Surgical procedureWe highlighted the curettage, suction, packing, and binding (CSPB) technique, a new off-clamp retroperitoneoscopic evacuation technique for sporadic RAMLs.MeasurementsDemographics, preoperative, intraoperative, and postoperative outcomes were assessed.Results and limitationsA total of 141 cases were included. The median (interquartile range [IQR]) tumour size was 7 (6.2–8.2) cm. The median (IQR) RENAL score was 10 (9–11). The median (IQR) operative time was 80 (65–125) min, with a median (IQR) estimated blood loss of 130 (90–362.5) ml. Conversion to neither open surgery nor standard laparoscopy occurred. The warm ischaemia time was zero for all cases. Postoperatively, 13 minor complications (Clavien grade 1) were recorded. No blood transfusions were reported. The glomerular filtration rate did not change significantly from preoperative period to 12-mo follow-up. Recurrence did not occur at the median follow-up period of 48 (36–60) mo. The retrospective design and lack of a control group are limitations of this study.ConclusionsOff-clamp retroperitoneoscopic tumour evacuation using the CSPB technique is feasible, safe, and effective for treating complex sporadic RAMLs.Patient summaryWe report a curettage, suction, packing, and binding technique for off-clamp retroperitoneoscopic evacuation of sporadic renal angiomyolipomas that leads to complete lesion clearance, excellent renal function preservation, and minimal perioperative complications.  相似文献   
10.
Wang  Ben  Deng  Yu-xuan  Yan  Sha  Xie  Hong-fu  Li  Ji  Jian  Dan 《Lasers in medical science》2021,36(3):649-655
Lasers in Medical Science - Acne scarring is one of the most common facial skin disorders. The appropriate treatments for acne scars in patients with rosacea have not been studied. This study was...  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