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   70721篇
  免费   4662篇
  国内免费   1950篇
耳鼻咽喉   500篇
儿科学   1308篇
妇产科学   828篇
基础医学   8223篇
口腔科学   1207篇
临床医学   6667篇
内科学   7396篇
皮肤病学   419篇
神经病学   9140篇
特种医学   2425篇
外国民族医学   2篇
外科学   5210篇
综合类   11022篇
现状与发展   6篇
预防医学   9887篇
眼科学   772篇
药学   7570篇
  99篇
中国医学   2359篇
肿瘤学   2293篇
  2024年   185篇
  2023年   1036篇
  2022年   1817篇
  2021年   2693篇
  2020年   2561篇
  2019年   2001篇
  2018年   1946篇
  2017年   1943篇
  2016年   2195篇
  2015年   2154篇
  2014年   4484篇
  2013年   4851篇
  2012年   4289篇
  2011年   4678篇
  2010年   3676篇
  2009年   3534篇
  2008年   3645篇
  2007年   3435篇
  2006年   3108篇
  2005年   2668篇
  2004年   2233篇
  2003年   1970篇
  2002年   1601篇
  2001年   1395篇
  2000年   1157篇
  1999年   980篇
  1998年   981篇
  1997年   959篇
  1996年   799篇
  1995年   758篇
  1994年   727篇
  1993年   633篇
  1992年   620篇
  1991年   597篇
  1990年   488篇
  1989年   448篇
  1988年   453篇
  1987年   425篇
  1986年   378篇
  1985年   517篇
  1984年   433篇
  1983年   271篇
  1982年   296篇
  1981年   286篇
  1980年   265篇
  1979年   172篇
  1978年   145篇
  1977年   141篇
  1976年   94篇
  1974年   49篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
101.
The objective of this review is to identify and review publications describing the impact of reduced somatosensation on balance. Based on knowledge of the association between specific somatosensory loss and deterioration of balance, conclusions can be made about role of somatosensation in standing balance.A systematic literature review is presented in which publications from the years 1993 through 2007 were searched in Medline and Embase. Medical Subject Headings (MESH) terms and free text words (related to balance, somatosensory loss, and lower limb) were used to perform the searches. Fifteen articles were selected for detailed review based on predetermined inclusion criteria, and three of the included articles described the effect of experimentally reduced somatosensation on balance in healthy subjects. Ten of the articles described balance in diabetic neuropathy (DN). The last two included articles described balance in Charcot-Marie-Tooth (CMT) disease type 1A (CMT1A) or type 2 (CMT2).The literature indicates that the tactile sensation is reduced in DN, CMT1A, and CMT2 and when the plantar surface of the feet was hypothermically anesthetized. Joint motion sensation seems to be impaired in patients with DN, and passive joint position sensation appears to be reduced in healthy subjects with anesthesia of ankle and foot from prolonged ischemia. This reduced somatosensation seems to have a negative effect on balance in patients with DN and CMT2; however, this appeared not to be the case in patients with CMT1A and in healthy subjects.  相似文献   
102.
103.
Physiologic assessment of diseases of the motor unit from the anterior horn cells to the muscles relies on a combination of needle electromyography (EMG) and nerve conduction studies (NCS). Both require a unique combination of knowledge of peripheral nervous system anatomy, physiology, pathophysiology, diseases, techniques, and electricity is necessary. Successful, high‐quality, reproducible EMG depends on the skills of a clinician in patient interaction during the physical insertion and movement of the needle while recording the electrical signals. These must be combined with the skill of analyzing electric signals recorded from muscle by auditory pattern recognition and semiquantitation. 10 , 52 This monograph reviews the techniques of needle EMG and waveform analysis and describes the types of EMG waveforms recorded during needle EMG. © 2009 Wiley Periodicals, Inc. Muscle Nerve 39: 244–270, 2009  相似文献   
104.
The disintegrin and metalloproteinase 10 (ADAM10) is a membrane‐anchored metalloproteinase with both proteolytic and disintegrin characteristics. Here, we investigate the expression, regulation, and functional role of ADAM10 in axonal outgrowth and myelination of the peripheral nerve. Expression pattern analysis of 11 ADAM family members in co‐cultures of rat dorsal root ganglia (DRG) neurons and Schwann cells (SCs) demonstrated the most pronounced mRNA expression for ADAM10. In further studies, ADAM10 was found to be consistently upregulated in DRG‐SC co‐cultures before the induction of myelination. Neurons as well as SCs widely expressed ADAM10 at the protein level. In neurons, the expression of ADAM10 was exclusively limited to the axons before the induction of myelination. Inhibition of ADAM10 activity by the hydroxamate‐based inhibitors GI254023X and GW280264X resulted in a significant decrease in the mean axonal length. These data suggest that ADAM10 represents a prerequisite for myelination, although its activity is not required during the process of myelination itself as demonstrated by expression analysis of myelin protein zero (P0) and Sudan black staining. Hence, during the process of myelin formation, ADAM10 is highly upregulated and appears to be critically involved in axonal outgrowth that is a requirement for myelination in the peripheral nerve. © 2009 Wiley‐Liss, Inc.  相似文献   
105.
高金亮 《实用骨科杂志》2007,13(9):528-529,576
目的探讨经后路椎间盘镜手术治疗合并腰椎管狭窄症的椎间盘突出症的临床应用。方法采用后路椎间盘镜进行单侧开窗减压术。通过术前标记腰椎正侧位片定位,于定位棘突间隙后正中偏患侧作长约1.5 cm小切口,逐级扩张后置入工作通道管,钻除部分椎板,置入内窥镜,于电视监视器下显露椎板、增生内聚的关节突、肥厚的黄韧带及突出的椎间盘髓核组织,彻底解除其对硬脊膜、神经根的压迫。结果本组共治疗合并腰椎管狭窄症的腰椎间盘突出症23例,平均随访7个月,按Prolo标准评定,治愈20例,有效2例,无效1例。结论本术式在严格掌握适应证前提下对合并腰椎管狭窄症的腰椎间盘突出症患者效果明显。  相似文献   
106.
本文通过多项止凝血实验指标和鲎试验对20例失代偿性肝硬化患者进行动态观察,发现血浆内毒素水平和ⅧR:Ag均增高.其他凝血因子和ATⅢ减低.纤维蛋白连接素减低.结果提示:(1)止凝血功能障碍与内毒素血症(ETM)并存,并与疾病的进展密切有关;(2)ETM的发生率和严重程度与肝硬化失代偿的程度有关;(3)ETM和止凝血功能异常的动态观察可作为判断预后的一项参考指标  相似文献   
107.
本文应用核磁共振法(NMR)测定了几种混合体系的 HLB 值与混合体系中各组分的 HLB 值。实验结果表明,混合体系中各组分在核磁共振图谱中的积分曲线高度也具有加和性。混合体系的 HLB 值是体系中各组分 HLB 值的加权平均值。因此,对混合体系的 HLB 值可以应用 NMR 法直接测定,也可应用 NMR 法测定各组分的 HLB值,通过计算求得,计算值与实测值完全一致。  相似文献   
108.
AIM: Peritonectomy procedures with intraperitoneal chemohyperthermia are an effective but costly treatment for peritoneal carcinomatosis (PC). Consequently a proper selection of patients is necessary. We evaluated the benefit of MRI prior to surgery, in the detection of two of the main surgery contraindications: bulky mesenteric tumors and bladder implants. METHODS: Three experts retrospectively reviewed abdominal and pelvic MRI from 19 cases of surgically proved PC (ovary: 7; colorectal: 7; gastric: 2; pseudomyxoma peritonei: 2; appendix: 1). RESULTS: Mesenteric tumors were always identified as hypersignal masses on axial and coronal fat suppression gadolinium-enhanced T1 images (n=3). Three out of five bladder implants were detected. The two cases of bladder implants that were not detected on MRI were missed because the bladder was not filled. The best sequence for the detection of bladder involvement was axial T2-weighted images with bladder filling. CONCLUSIONS: Evaluating the preoperative resectability of PC is crucial for patient management. MRI seems to reliably detect bulky mesenteric tumors and bladder implants on condition the bladder is filled and appropriate sequences are used.  相似文献   
109.
Overview of the Clinical Efficacy of Lamotrigine   总被引:5,自引:4,他引:1  
A. Richens  A. W. C. Yuen 《Epilepsia》1991,32(S2):S13-S16
Summary: Testing the efficacy of lamotrigine (LTG) in epileptic patients has been approached in several ways. The first pilot study examined the effect of a single dose of LTG in patients with frequent interictal spikes, and a reduction in spike frequency was observed. Subsequently, single doses reduced photosensitivity in appropriate patients. Single-blind administration of LTG for 1 week in addition to the patients' regular antiepileptic drugs (AEDs), in patients with refractory seizures, reduced seizures despite the short duration of therapy. This regimen was continued using a placebo-controlled crossover study with 1-week duration of treatment. Efficacy in partial and tonic-clonic seizures was subsequently confirmed in four double-blind crossover studies; a meta-analysis of these four studies showed a 30% reduction in partial seizures despite the intractable nature of the seizures in the patients included. Current studies aim at evaluating the drug as monotherapy and in different seizure types.  相似文献   
110.
Bacterial ghosts (BGs) are empty bacterial envelopes of Gram-negative bacteria produced by controlled expression of cloned gene E, forming a lysis tunnel structure within the envelope of the living bacteria. BGs are devoid of cytoplasmic content and possess all bacterial bio-adhesive surface properties in their original state while not posing any infectious threat. BGs are ideally suited as an advanced drug delivery system (ADDS) for toxic substances in tumor therapy. The inner space of BGs can be loaded with either single components or combinations of peptides, drugs or DNA which provides an opportunity to design new types of (polyvalent) drug delivery vehicles. Uptake of BGs loaded with Doxorubicin (Dox) by CaCo2 cells led to effective Dox release from endo-lysosomal compartments and accumulation in the nucleus. Viability and proliferative capacity of the cells were significantly decreased (2–3 orders of magnitude) after internalization of Dox loaded BGs as compared to cells incubated with free Dox. The same effect was observed with leukemia cells. Melanoma cells also revealed a high capability to internalize BGs. These results indicate that BGs are able to target a range of types of cancer. BGs have also been investigated as DNA delivery vectors. Studies show DNA loaded BGs are efficiently phagocytosed and internalized by both professional APCs and tumor cells with up to 82% of cells expressing the plasmid-encoded reporter gene. Our studies with BGs as an ADDS system contribute (i) to optimize drug delivery for the treatment of cancer; (ii) define specific conditions for selection and preparation of BG formulations; (iii) and provide a background for the clinical application of BGs in cancer therapy.  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