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   405篇
  免费   14篇
  国内免费   24篇
儿科学   15篇
妇产科学   40篇
基础医学   44篇
口腔科学   5篇
临床医学   48篇
内科学   91篇
皮肤病学   5篇
神经病学   14篇
特种医学   52篇
外科学   40篇
综合类   7篇
预防医学   13篇
眼科学   2篇
药学   46篇
肿瘤学   21篇
  2023年   1篇
  2022年   2篇
  2021年   9篇
  2020年   6篇
  2019年   12篇
  2018年   12篇
  2017年   6篇
  2016年   9篇
  2015年   6篇
  2014年   3篇
  2013年   15篇
  2012年   7篇
  2011年   12篇
  2010年   9篇
  2009年   15篇
  2008年   14篇
  2007年   31篇
  2006年   14篇
  2005年   10篇
  2004年   17篇
  2003年   10篇
  2002年   11篇
  2001年   5篇
  2000年   5篇
  1999年   15篇
  1998年   17篇
  1997年   14篇
  1996年   19篇
  1995年   19篇
  1994年   15篇
  1993年   22篇
  1992年   4篇
  1991年   7篇
  1990年   8篇
  1989年   10篇
  1988年   9篇
  1987年   6篇
  1986年   3篇
  1985年   7篇
  1984年   4篇
  1983年   3篇
  1982年   6篇
  1981年   3篇
  1980年   2篇
  1979年   3篇
  1978年   3篇
  1976年   2篇
  1975年   1篇
排序方式: 共有443条查询结果,搜索用时 15 毫秒
41.
目的:采用定量分析方法比较体育与非体育专业大学生静态平衡能力,分析运动及性别对大学生静态平衡功能的影响。方法:于2007-01/03选取首都体育学院在校大学生共78名为受试对象,其中体育(武术)专业学生40名,非体育(康复)专业学生38名。所有选取对象了解试验目的,并同意参与本实验。采用意大利PosturalEqua平静分析系统,对实验对象分别在睁眼60s、闭眼60s两种状态下测试其静态平衡的各项指标,包括压力中心,线形图总长度,最大摆幅,线形图面积,LFS指数,压力分布,稳定性图及隆伯格值。结果:78名为受试对象均进入结果分析。①两专业学生压力中心X轴短于Y轴、压力分布前(%)高于后(%)(P<0.01)。②在闭眼状态下,体育专业男大学生在指标LFS指数和额状面上大于非体育专业(P<0.05)。③非体育业大学生在睁眼状态下,Y值女性小于男性,额状面值女性大于男性。男、女生睁闭眼差值进行比较时,女性在线形图总长度、额状面和LFT指数均大于男性(P<0.01),而线形图面积小于男性(P<0.05)。④体育专业大学生在睁眼状态下,指标参数Y值女性小于男性,额状面值女性大于男性;闭眼状态下,指标参数Y值女性小于男性,额状面值和LFS值女性大于男性。男、女生睁闭眼差值比较,女性在线形图总长度、额状面和LFT指数均大于男性(P<0.05,P<0.01),而线形图面积小于男性(P<0.05)。结论:①运动训练对大学生静态平衡影响不大,但对男性大学生的某些平衡指标却有显著影响。②性别对大学生的静态平衡均产生影响,表现为男性平衡的微控制能力优于女性。  相似文献   
42.
43.
The effect of prestorage irradiation on posttransfusion red cell survival   总被引:1,自引:0,他引:1  
Transfusion-associated graft-versus-host disease (TA-GVHD) may occur whenever immunologically competent allogeneic lymphocytes are transfused to an immunocompromised recipient. Irradiation of blood components eliminates the risk of TA-GVHD but may damage the cellular elements in the transfused component, particularly if the cells are stored for prolonged periods in the irradiated state. To study the effect of irradiation on long-term storage of red cells, AS-1 red cells from eight normal subjects were prepared on two occasions. On one occasion, the units were stored as standard AS-1 red cells for 42 days at 4 degrees C; on the other, they were exposed to 3000 cGy radiation within 4 hours of collection and then were stored as AS-1 red cells for 42 days at 4 degrees C. The donations were at least 12 weeks apart. Irradiated units demonstrated significant elevations in poststorage plasma hemoglobin (Hb) (623 +/- 206 vs. 429 +/- 194 g/dL [6230 +/- 2060 vs. 4290 +/- 1940 g/L], p less than 0.02) and plasma potassium (78 +/- 4 vs. 43 +/- 9 mEq/L [78 +/- 4 vs. 43 +/- 9 mmol/L], p less than 0.01) and significant decreases in red cell ATP (1.9 +/- 0.2 vs. 2.1 +/- 0.3 microM/g Hb, p less than 0.04) and 24-hour posttransfusion red cell recovery (68.5 vs. 78.4%, p less than 0.02), as compared to nonirradiated units. It can be concluded that irradiation with 3000 cGy damages red cells and that long-term storage in the irradiated state may enhance this damage. Red cells should not be stored for 42 days after irradiation with 3000 cGy.  相似文献   
44.
Fluorescence in situ hybridization (FISH) was used to detect 6q-, 11q-, +12, 13q-, 17p- and translocations involving 14q32 in interphase nuclei from blood and/or bone marrow from 113 patients with B-cell chronic lymphocytic leukaemia (B-CLL). A total of 87 patients (77%) had a FISH anomaly: 13q- x 1 was most frequent (64%) followed by 13q- x 2 (28%), +12 (25%), 11q- (15%), 17p- (8%) and 6q- (0%). FISH results for blood and bone marrow cells in 38 patients were similar. Purified CD5+/CD19+ cells from blood were studied in eight patients and results indicate that in some patients not all B cells have FISH anomalies. We used a defined set of hierarchical FISH risk categories to compare FISH results by stable versus progressive disease, age, sex, Rai stage, CD38+ expression and IgVH mutational status. Significant differences in FISH risk distributions were associated with Rai stage, disease status and CD38+, but not by age, sex or IgVH mutational status. To look for baseline factors associated with high-risk disease, multivariate analysis of age, sex, Rai stage, CD38+ and disease status versus FISH risk category was performed. Importantly, only CD38+ was significantly associated with high-risk FISH categories (+12, 11q- and 17p-) after adjustment for the effects of other variables.  相似文献   
45.
复合富血小板血浆的酶处理异种骨修复兔桡骨缺损   总被引:1,自引:4,他引:1  
目的:自源性的富血小板血浆可促进骨组织及软组织的修复,又不存在疾病传播及免疫排斥的可能。实验拟验证应用复合富血小板血浆的酶处理异种骨修复节段性骨缺损的可行性。方法:实验于2006-07/12在解放军昆明总医院实验动物中心完成。①实验分组:选用新西兰大耳白兔20只,体质量2.0~2.5kg,共40只前肢,随机分为复合酶组,单纯酶组,脱蛋白骨组,空白组。每组共10个标本。②实验方法:制作富血小板血浆及酶处理的异种骨并制备桡骨中段15mm的节段性骨缺损模型,将上述骨材料植入兔桡骨缺损处,其中复合酶组:植入复合富血小板血浆的酶处理异种骨;单纯酶组:植入酶处理异种骨;脱蛋白骨组:植入部分脱蛋白骨;空白组:不植入任何材料。③实验评估:分别于术后4,8,12周取材,X线片及苏木精-伊红染色分别观察骨缺损区的新骨形成情况。同时对各组骨密度进行测定。结果:纳入新西兰大耳白兔20只,均进入结果分析,所有手术无术后感染,无动物死亡,植入骨无脱落。①所有动物麻醉苏醒后均恢复进食,2周伤口愈合,未出现感染及渗液等。富血小板血浆中的血小板含量均为全血的4倍以上。②在同一时间点,酶处理后异种骨与部分脱蛋白骨在成骨能力方面差异无显著性意义,而复合富血小板血浆的酶处理异种骨在8周时骨缺损部分修复;12周时完全修复。空白组骨缺损未修复。③8,12周时复合酶组骨密度较单纯酶组、脱蛋白骨组高,差异有显著性意义(P<0.05);单纯酶组与脱蛋白骨组比较无明显差异(P>0.05)。结论:经酶处理后异种骨可用于节段性骨缺损的修复,复合富血小板血浆后有明显加速骨愈合的作用。  相似文献   
46.
47.
Percutaneous drainage access: a simplified coaxial technique   总被引:1,自引:0,他引:1  
We describe an access technique that we have used in 150 nephrostomy and biliary drainage procedures and for access to some abscesses and viscera. The system provides safe coaxial access with a 22-gauge removable hub needle, which then acts as a guide wire and is replaced by an 18-gauge cannula. A major advantage is that only one guide wire is used (0.038-inch) for the entire drainage procedure. No significant complications have occurred to date with this method.  相似文献   
48.
We report a rare case of early-stage endometrial adenocarcinoma in a 22 year old nullipara with polycystic ovaries undergoing conservative treatment. Pretreatment evaluation including tumour grade, depth of myometrial invasion, tumour size, hormone receptor status and flow cytometric analysis indicated a favourable prognosis. The patient underwent repeat endometrial curettage and a 6 month period of therapy with megestrol acetate and tamoxifen. A combination contraceptive pill was then prescribed to ensure withdrawal of the menstrual cycle thereafter. Now, 1 year after the last curettage, there is no evidence of disease. During the treatment period, hysteroscopy allowed for a more precise approach in panoramically examining the tumour nest in the endometrial cavity, and the subsequent endometrial response to hormone therapy. Laparoscopy using bulldog clamps applied to the isthmic portion of the Fallopian tubes prevented i.p. spread of endometrial tissue from retrograde regurgitation during hysteroscopy. Laparoscopic ovarian electrocautery resulted in the reduction of abnormal hypervascularization on the surface of polycystic ovaries postoperatively but caused a peri-ovarian adhesion complication. It is interesting that this case posed a unique opportunity to demonstrate the tumour regression under the assistance of laparoscopy and hysteroscopy.   相似文献   
49.
API2-MALT1 fusion and aneuploidy are common chromosomal abnormalities in MALT lymphoma. In studying their incidence and relationship in primary pulmonary MALT lymphomas, a translocation involving MALT1 and IGH was also identified. In all, 28 primary pulmonary MALT lymphomas were studied by fluorescence in situ hybridization using an API2-MALT1 probe and multiple centromeric probes, as well as IGH-BCL2, IGH-MALT1, and MALT1 breakapart probes in selected cases. Seven (25%) had API2-MALT1 fusion; all seven lacked aneuploidy except for two with trisomy 3 in a small clone. Three (11%) had IGH-MALT1 fusion; two also showed trisomy 3 and 12. A total of 11 (39%) had aneuploidy only, with trisomy 3 and 18 being the most common. Ectopic nuclear bcl-10 expression, which has been previously associated with API2-MALT1, was seen by immunohistochemistry in 86% of API2-MALT1 fusion-positive cases, one IGH-MALT1 fusion-positive case, two aneuploidy-only cases, and two normal cases. In primary pulmonary MALT lymphomas, cytogenetic abnormalities are common (75%) and heterogeneous, encompassing API2-MALT1 and IGH-MALT1, which are mutually exclusive, as well as aneuploidy, which may be present in the latter but is rare in the former. Ectopic nuclear bcl-10 expression is associated with API2-MALT1 but may also be seen in IGH-MALT1 fusion-positive, aneuploidy-only, and normal cases.  相似文献   
50.
Increased local blood supply is thought to be one of the mechanisms underlying oxidative adaptations to interval training regimes. The relationship of exercise intensity with local blood supply and oxygen availability has not been sufficiently evaluated yet. The aim of this study was to examine the effect of six different intensities (40–90% peak oxygen uptake, VO2peak) on relative changes in oxygenated, deoxygenated and total haemoglobin (ΔO2Hb, ΔHHb, ΔTHb) concentration after exercise as well as end‐exercise ΔHHb/ΔVO2 as a marker for microvascular O2 distribution. Seventeen male subjects performed an experimental protocol consisting of 3 min cycling bouts at each exercise intensity in randomized order, separated by 5 min rests. ΔO2Hb and ΔHHb were monitored with near‐infrared spectroscopy of the vastus lateralis muscle, and VO2 was assessed. ΔHHb/ΔVO2 increased significantly from 40% to 60% VO2peak and decreased from 60% to 90% VO2peak. Post‐exercise ΔTHb and ΔO2Hb showed an overshoot in relation to pre‐exercise values, which was equal after 40–60% VO2peak and rose significantly thereafter. A plateau was reached following exercise at ≥80% VO2peak. The results suggest that there is an increasing mismatch of local O2 delivery and utilization during exercise up to 60% VO2peak. This insufficient local O2 distribution is progressively improved above that intensity. Further, exercise intensities of ≥80% VO2peak induce highest local post‐exercise O2 availability. These effects are likely due to improved microvascular perfusion by enhanced vasodilation, which could be mediated by higher lactate production and the accompanying acidosis.  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