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   8441篇
  免费   420篇
  国内免费   71篇
耳鼻咽喉   35篇
儿科学   103篇
妇产科学   49篇
基础医学   439篇
口腔科学   110篇
临床医学   1908篇
内科学   405篇
皮肤病学   33篇
神经病学   95篇
特种医学   205篇
外科学   723篇
综合类   1210篇
预防医学   2624篇
眼科学   45篇
药学   660篇
  33篇
中国医学   184篇
肿瘤学   71篇
  2024年   8篇
  2023年   99篇
  2022年   188篇
  2021年   320篇
  2020年   367篇
  2019年   243篇
  2018年   191篇
  2017年   261篇
  2016年   220篇
  2015年   264篇
  2014年   695篇
  2013年   662篇
  2012年   727篇
  2011年   793篇
  2010年   582篇
  2009年   443篇
  2008年   408篇
  2007年   422篇
  2006年   362篇
  2005年   243篇
  2004年   217篇
  2003年   181篇
  2002年   152篇
  2001年   124篇
  2000年   77篇
  1999年   82篇
  1998年   58篇
  1997年   76篇
  1996年   56篇
  1995年   47篇
  1994年   44篇
  1993年   35篇
  1992年   30篇
  1991年   27篇
  1990年   28篇
  1989年   18篇
  1988年   27篇
  1987年   15篇
  1986年   13篇
  1985年   25篇
  1984年   13篇
  1983年   7篇
  1982年   18篇
  1981年   5篇
  1980年   9篇
  1979年   11篇
  1978年   9篇
  1977年   10篇
  1976年   14篇
  1975年   4篇
排序方式: 共有8932条查询结果,搜索用时 31 毫秒
61.
膝关节动脉的血液供应   总被引:9,自引:0,他引:9  
姚作宾 《解剖学报》1989,20(2):125-129
本文通过动脉灌注,对120侧不同年龄(新生儿至87岁)尸体的膝关节骨性部和软组织的血液供应分别进行了研究。新生儿的膝动脉在软骨内分布呈节段性,软骨骨化后,骨骺和髌骨的动脉间建立广泛的吻合。骺软骨板分隔膝关节的骨骺与干骺端。随骺板的闭合,两者间有血管互相交通。骺板的血液供应来自骺动脉、干骺动脉和滋养动脉终末的毛细血管袢以及骨膜动脉网的小支。髌骨的动脉分3组,发自髌前丛和髌周动脉环。滑膜和髌下脂垫的血管分布丰富。肌睫和韧带在骨的附着处缺乏血管。成人半月板外1/5有血管分布,内4/5无血管。本文对膝关节血管分布的临床意义作了简要讨论。  相似文献   
62.
63.
The musk shrew, Suncus murinus, is one of the primitive mammals and has a pair of palatine tonsils. In the present study, we investigated the blood microvascular architecture of the tonsil in this animal by scanning electron microscopy of corrosion casts. The paranodular arterioles entered the lymph nodule to form a coarse capillary plexus within the nodule. Some of the arterioles reached the dome region to give rise to a fine meshwork of dome subepithelial capillaries. This dome subepithelial capillary network did not show any hairpin or switch-back patterns, as seen in human and rabbit tonsils. Both of the nodular and dome capillaries were drained into the postcapillary venules in the periphery of the nodular or the paranodular region. On the surface of these cast venules, oval-shaped indentations were seen corresponding to the luminal surface of the high endothelial venules. These venules were collected into the large vein at the bottom of the tonsil. The blood vascular architecture of the musk shrew tonsil is basically the same as those of other mucosa-associated lymphoid tissues in mammals.  相似文献   
64.
Summary Muscle fiber type composition and capillary supply in rat diaphragm were investigated after 14 weeks of endurance training: body weight and muscle fiber area were significantly decreased, the muscle fiber type composition, capillary to fiber ratio and number of capillaries around each fiber type were unchanged, and the capillary density and number of capillaries around each fiber relative to fiber type areas were significantly increased. These small fiber areas and increased capillary supplies in the trained rats would facilitate oxygen transport to all parts of the muscle fiber during exercise. It is concluded that the changes observed in the trained rat diaphragm appear to enhance the capacity for oxidative metabolism.  相似文献   
65.
The abductor hallucis muscle flap is commonly used as a proximally-based flap in the management of ankle, heel, and midfoot lesions, where it is ideally suited for closing defects. This study investigates the anatomical details of this muscle in 13 fresh male cadavers. The medial plantar artery (MPA) was studied by dissection and macroscopic analyses to document the relationship of its superficial and deep branches with respect to the abductor hallucis muscle (AHM). Three main patterns could be described. In Pattern A (54%) the MPA divides into two branches. The deep branch reaches the deep surface of the AHM, supplying its proximal part, and the superficial branch courses between the AHM and the flexor digitorum brevis, to end as the first plantar metatarsal artery. The latter supplies two to three small branches to the distal part of the AHM. The fibers of the AHM end symmetrically on the two sides of the tendon and the muscle presents an arciform shape. The MPA, in Pattern B (38%), lacks a deep branch and continues along the lateral border of the AHM as a superficial branch that supplies proximal and distal collaterals to the muscle. The muscle fibers of the AHM end mainly on the medial side of the tendon. The muscle belly presents an arciform shape and is located on the medial margin of the foot superomedially with respect to Pattern A. In Pattern C (8%) the MPA continues as a large deep branch on the deep surface of the AHM and ends as the medial collateral artery of the big toe. A smaller superficial branch of the MPA provides a few collaterals to the AHM from its proximal part and to the flexor digitorum brevis in its distal part. The AHM fibers end mainly on the lateral side of the tendon and morphologically the muscle presents a straight line on the sole of the foot compared to Pattern A. Although Patterns B and C, from a surgical point of view, necessitate interruption of the main trunk of the MPA, Pattern A may permit the vascularization of the muscles of the medial side of the sole of the foot by the superficial trunk of the MPA. Because preoperative radiological study of the plantar vessels correlate with the morphological characteristics of the AHM observed during surgery, such imaging may be useful in determining the appropriate flap design based on the patient's unique pattern of MPA branching.  相似文献   
66.
应用微血管灌注透明法观察研究5具成人周围神经干标本.重点观察神经自然分束部位微血管形态和分支分布规律.神经干内有非常完兽的血供系统.手术中循神经自然分束进行追踪分离,不会对神经血供产生明显影响.但在张力下牵拉缝合神经,将对神经干血供产生严重影响.神经束膜缝合比神经外膜缝合更强调在无张力下进行.  相似文献   
67.
BACKGROUND: The blood supply to the tubal corner of the uterus may originate from the uterine and ovarian arteries. The border of supply from the arteries has been found to move in young women; the change seemed dependent on ovarian steroid production. The present work investigated whether the border of supply could differ between the two sides of the uterus in the same woman having one dominant follicle (>10 mm). METHODS: Vagina was flushed with saline of room temperature in 15 women with a dominant follicle >10 mm. The temperature was measured in the mid-uterine lumen and in the tubal corner of the uterus at 2, 5 and 7 min after starting cooling. The investigation was repeated 30 min later measuring the temperature in the other tubal corner. RESULTS: The temperature decrease was, as found in previous investigations, more pronounced in the uterine cavity than in the tubal corners. However, a difference was found between the two tubal corners. At all measurement times the decrease was significantly smaller in the tubal corner corresponding to the dominant follicle than in the contralateral side. CONCLUSIONS: In our model, 'cold' is transferred from the vaginal venous blood to the uterine artery and the cooling defines the supply area of the uterine artery. Therefore, the results indicate that the area of supply from the ovarian artery in the tubal corner ipsilateral to the dominant follicle is greater than that in the contralateral side. It is possible to speculate that this difference is related to the hormonal production of the dominant follicle.  相似文献   
68.
The TCR-CD3 complex consists of the clonotypic disulfide-linked TCRalphabeta or TCRdeltagamma heterodimers, and the invariant CD3delta, epsilon, gamma and zeta chains. We generated plasmid constructs expressing the extracellular domains of the CD3delta, epsilon or gamma subunits fused to human IgG1 Fc. Recombinant fusion proteins consisting of individual CD3delta, epsilon or gamma subunits reacted poorly with anti-CD3 mAb including G19-4, BC3, OKT3 and 64.1. Co-expression of the CD3epsilon-Ig with either the CD3delta-Ig (CD3epsilondelta-Ig) or the CD3gamma-Ig (CD3epsilongamma-Ig) resulted in fusion proteins with much increased binding to G19-4. A brief acid treatment of the purified CD3epsilondelta-Ig fusion protein substantially improved its binding to BC3, OKT3 and 64.1. Surface plasmon resonance analysis revealed that the dissociation constants for CD3epsilondelta-Ig and anti-CD3 mAb ranged from 10(-8) to 10(-9) M. Based on these results, a single-chain (sc) construct encoding the CD3delta chain linked to the CD3epsilon chain with a flexible linker followed by human IgG1 Fc was expressed. The sc CD3deltaepsilon-scIg reacted with anti-CD3 mAb without requiring acid treatment. Moreover, anti-CD3 mAb bound CD3epsilondelta-Ig at a higher affinity than CD3epsilongamma-Ig, suggesting potential structural differences between the CD3epsilondelta and CD3epsilongamma subunits. In summary, we report the expression of soluble recombinant CD3 proteins that demonstrate structural characteristics of the native CD3 complex expressed on the T cell surface. These CD3 fusion proteins can be used to further analyze the structure of the TCR-CD3 complex, and to identify molecules that can interfere with TCR-CD3-mediated signal transduction by disrupting the interaction between CD3 and TCR subunits.  相似文献   
69.
Association between HLA and Japanese patients with rheumatoid arthritis   总被引:12,自引:0,他引:12  
Japanese patients with rheumatoid arthritis (RA) were observed to have a statistical association with HLA-DR4, MT3. Strong association between the clinical severity of RA and HLA was also observed. Male patients had a stronger association with HLA than female patients. Males are more resistant to RA than females. This suggested that the threshold of liability for RA is higher in males than in females. Japanese patients with RA with systemic vasculitis were negative for HLA-Bw44 and had antilymphocytotoxic autoantibody, indicating that RA with systemic vasculitis is different in etiology from RA without systemic vasculitis.  相似文献   
70.
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