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   94455篇
  免费   5297篇
  国内免费   158篇
耳鼻咽喉   1313篇
儿科学   2999篇
妇产科学   2352篇
基础医学   13494篇
口腔科学   3229篇
临床医学   8889篇
内科学   18071篇
皮肤病学   2129篇
神经病学   9806篇
特种医学   3824篇
外科学   12796篇
综合类   397篇
一般理论   44篇
预防医学   6653篇
眼科学   1922篇
药学   6536篇
中国医学   195篇
肿瘤学   5261篇
  2023年   579篇
  2022年   617篇
  2021年   1373篇
  2020年   1125篇
  2019年   1371篇
  2018年   2330篇
  2017年   1912篇
  2016年   2305篇
  2015年   2074篇
  2014年   2516篇
  2013年   4201篇
  2012年   5548篇
  2011年   5998篇
  2010年   3170篇
  2009年   2424篇
  2008年   5601篇
  2007年   5874篇
  2006年   5583篇
  2005年   5558篇
  2004年   5211篇
  2003年   5227篇
  2002年   5044篇
  2001年   3134篇
  2000年   3750篇
  1999年   2244篇
  1998年   860篇
  1997年   725篇
  1996年   581篇
  1995年   526篇
  1994年   517篇
  1993年   465篇
  1992年   589篇
  1991年   532篇
  1990年   454篇
  1989年   542篇
  1988年   417篇
  1987年   433篇
  1986年   427篇
  1985年   485篇
  1984年   471篇
  1983年   389篇
  1982年   391篇
  1981年   339篇
  1980年   284篇
  1979年   353篇
  1978年   272篇
  1977年   314篇
  1976年   264篇
  1975年   258篇
  1973年   257篇
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
51.
The galanin peptide family and its three receptors have with compelling evidence been implicated in several high-order physiological disorders. The co-localization with other neuromodulators and the distinct up-regulation during and after pathological disturbances has drawn attention to this neuropeptide family. In the current study we present data on receptor binding and functional response for a novel galanin receptor type 2 (GalR2) selective chimeric peptide, M1145 [(RG)2-N-galanin(2-13)-VL-(P)3-(AL)2-A-amide]. The M1145 peptide shows more than 90-fold higher affinity for GalR2 over GalR1 and a 76-fold higher affinity over GalR3. Furthermore, the peptide yields an agonistic effect in vitro, seen as an increase in inositol phosphate (IP) accumulation, both in the absence or the presence of galanin. The peptide design with a N-terminal extension of galanin(2-13), prevails new insights in the assembly of novel subtype specific ligands for the galanin receptor family and opens new possibilities to apply the galanin system as a putative drug target.  相似文献   
52.
A young patient had an auriculo-ventricular block and a distal myopathy with muscle biopsy findings suggestive of inclusion body myositis. What was most unusual was the presence of numerous sarcoplasmic bodies identified as desmin by electron microscopy and immunocytochemistry. The nosological situation of this condition is discussed.  相似文献   
53.
54.
PURPOSE: Temporomandibular joint (TMJ) arthroscopy has been considered a safe surgical procedure in the treatment of TMJ derangement. However, it is not exempt from complications. This study evaluates the complications of arthroscopy in patients with internal derangement of TMJ. PATIENTS AND METHODS: Five hundred consecutive patients (670 joints) with TMJ derangement who underwent arthroscopy between 1995 and 2004 were retrospectively analyzed. All the patients were classified as II to V in the Wilkes classification. Lysis and lavage, electrocautery of the posterior ligament, injection of corticoids, injection of ethanolamine, myotomy of lateral pterygoid muscle attachments, myotomy and electrocautery, motor debridement, injection of sodium hyaluronate, and meniscal suture were performed in different patients. RESULTS: Complications were recognized during or immediately after the surgery. They were observed in 5 of 341 (1.26%) arthroscopies of the right TMJ and 4 of 329 (1.21%) arthroscopies of the left TMJ. A 1.34% complication rate was found in the whole series. No blood clots within the external auditory canal were observed. Bleeding within the superior TMJ space was observed in 57 cases (8.5%), 36 of them in the right TMJ and 21 in the left TMJ, but they were not considered as true complications. Lacerations of the external auditory canal were found in 2 cases (0.3%), with no cases of perforation of the tympanic membrane. Lesion of the auriculotemporal nerve was observed in a case. Paresia of the facial nerve was found in 4 cases (0.6%). Alteration of visual accuracy of the ipsilateral eye was also observed in a patient immediately after the surgery. CONCLUSION: Special care must be taken to reduce complications within the upper joint space by means of an adequate instrumentation and by paying attention to essential points of the arthroscopic technique.  相似文献   
55.
Evidence of the effect of exercise on bone loss comes mainly from studies in voluntary postmenopausal women, and no population-based, long-term interventions have been performed. The purpose of this population-based, randomized, controlled trial was to determine the effect of long-term impact exercise on bone mass at various skeletal sites in elderly women with low bone mineral density (BMD) at the radius and hip. Participants ( n =160) were randomly assigned to 30 months either of supervised and home-based impact exercise training or of no intervention. The primary outcome measures were femoral neck, trochanter and total hip BMD, and the secondary outcomes were bone density measures at the radius and calcaneum. Outcomes were assessed at baseline, 12 months and 30 months using blinded operators. The analyses were performed on an intention-to-treat analysis. Mean femoral neck and trochanter BMD decreased in the control group [–1.1%, 95% confidence interval (CI) –0.1% to –2.1% and –1.6%, 95% CI –0.4% to –2.7%], while no change occurred in the exercise group. Mean trochanter BMC decreased more in the control group (–7.7%, 95% CI –9.7% to –5.6% vs. –2.9%, 95% CI –5.3 to –0.9). There were six falls that resulted in fractures in the exercise group and 16 in the control group during the 30-month intervention ( P =0.019). A significant bone loss occurred in both groups at the radius and calcaneum. In multivariate analysis, weight gain was associated with increased BMD and BMC at all femur sites both in the exercise group and in the pooled groups. In conclusion, impact exercise had no effect on BMD, while there was a positive effect on BMC at the trochanter. Exercise may prevent fall-related fractures in elderly women with low bone mass.There was no conflict of interest.  相似文献   
56.
In order to establish a venom fingerprint and a peptide profile of the Lasiodora parahybana tarantula venom gland, we used conventional methods such as reversed phase liquid chromatography coupled to an electrospray-ionisation hybrid quadrupole time of flight mass spectrometer (LC/ESI-QqTOFMS), matrix-assisted laser desorption/ionization time-of-flight-MS (MALDI-TOFMS) and direct study of L. parahybana venom by nanospray-ionization QqTOFMS (nanoESI-QqTOFMS) and a new technology for the direct analysis of fresh tissues using MALDI-TOFMS. The analysis of the crude venom allowed the characterization of specific juvenile and adult biomarkers. In situ MALDI analysis of L. parahybana venom gland sections revealed different peptide expression levels all along the gland and non-processed peptide precursors, demonstrating the power of the method for the dynamic investigation of peptide evolution in the venom gland of spiders.  相似文献   
57.

Background  

It is well known that physicians' night-call duty may cause impaired performance and adverse effects on subjective health, but there is limited knowledge about effects on sleep duration and recovery time. In recent years occupational stress and impaired well-being among anaesthesiologists have been frequently reported for in the scientific literature. Given their main focus on handling patients with life-threatening conditions, when on call, one might expect sleep and recovery to be negatively affected by work, especially in this specialist group. The aim of the present study was to examine whether a 16-hour night-call schedule allowed for sufficient recovery in anaesthesiologists compared with other physician specialists handling less life-threatening conditions, when on call.  相似文献   
58.
In the past, addiction disorders were considered to be mainly substance use disorders. The main focus has been on dependence disorders. Dependence criteria do not differ substantially in the two main classification systems ICD and DSM, while harmful use (ICD) and abuse (DSM) criteria show much less concordance. Presently diagnostic criteria for behavioral addiction disorders are only available for pathological gambling, however, under the category of disorders of impulse control, while other disorders have to be categorized under disorders not otherwise specified. Evidence of neurobiological similarities implies that future ICD and DSM revisions, in addition to other needed changes, will group behavioral addiction and substance use disorders together.  相似文献   
59.
Within the treatment algorithm for accident victims there is an additional risk potential beyond those associated with the complex treatment procedures in primary medical care, and it is inherent in the interfaces between the different treatment sectors. Besides the substantial loss of time and information, such factors as technical incompatibilities between items of equipment, differing treatment concepts and responsibilities and difficulties in transfer and positioning can put the patient at risk. The entire process involves multiple interfaces both between preclinical and clinical medical care and within the various treatment sectors, e.g. when a preclinical patient is transferred from ground medical staff to the air rescue team. The goal of an efficient treatment algorithm should be the reduction of multiple interfaces in order to optimize the various procedures. Future concepts directed at optimizing trauma management should therefore make some contribution to interface reduction.  相似文献   
60.
A multiply injured patient’s airway is primarily secured with a laryngeal tube by the responding EMS. For helicopter transfer the flight physician decides not to intubate the patient’s trachea. Mechanical ventilation was performed without complications.  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