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   5870篇
  免费   536篇
  国内免费   159篇
耳鼻咽喉   127篇
儿科学   115篇
妇产科学   15篇
基础医学   375篇
口腔科学   195篇
临床医学   1106篇
内科学   784篇
皮肤病学   29篇
神经病学   272篇
特种医学   188篇
外科学   1027篇
综合类   809篇
现状与发展   1篇
预防医学   406篇
眼科学   84篇
药学   513篇
  17篇
中国医学   288篇
肿瘤学   214篇
  2024年   23篇
  2023年   125篇
  2022年   210篇
  2021年   349篇
  2020年   332篇
  2019年   295篇
  2018年   277篇
  2017年   278篇
  2016年   258篇
  2015年   226篇
  2014年   461篇
  2013年   496篇
  2012年   348篇
  2011年   333篇
  2010年   290篇
  2009年   259篇
  2008年   249篇
  2007年   231篇
  2006年   243篇
  2005年   191篇
  2004年   153篇
  2003年   130篇
  2002年   128篇
  2001年   111篇
  2000年   78篇
  1999年   54篇
  1998年   49篇
  1997年   48篇
  1996年   48篇
  1995年   52篇
  1994年   31篇
  1993年   32篇
  1992年   24篇
  1991年   22篇
  1990年   17篇
  1989年   14篇
  1988年   18篇
  1987年   12篇
  1986年   10篇
  1985年   17篇
  1984年   8篇
  1983年   8篇
  1982年   7篇
  1981年   5篇
  1980年   4篇
  1979年   3篇
  1978年   2篇
  1976年   3篇
  1974年   2篇
  1972年   1篇
排序方式: 共有6565条查询结果,搜索用时 443 毫秒
31.
徐峰  周跃  陈庄洪 《临床外科杂志》2008,16(11):771-773
目的通过对正常人螺旋CT多平面重建检查,并对其行后路经关节螺钉内固定技术相关形态学参数的测量,为临床提供患者个体化手术相关信息。方法对60例正常人进行寰椎的螺旋CT检查,获取相关参数并进行分析。采用枢椎下关节突正中为进钉点模拟寰枢椎后路经关节螺钉内固定术,在螺旋CT重建上获得轴面和矢状面的正确倾斜角度。C2峡部高度和宽度,理想的螺钉长度,理想的螺钉矢状面和轴面倾斜度,以及理想的螺钉路径与椎动脉沟之问距离。结果C2峡部高度为(8.02±1.92)mm,峡部宽度(6.05±1.32)mm,理想的螺钉长度为(41.22±4.48)mm,螺钉矢状面倾斜度为53.87°±5.61°,与内向成角(14.81°±2.81°)。10侧(8%)峡部狭窄(宽度或高度小于5mm),测量其椎动脉沟与理想螺钉途径之间距离,有12例(10%)小于2.5mm,因此总共有22侧(18%)存在潜在椎动脉损伤风险。结论术前对每个患者行CT检查十分必要,能充分地了解个体的解剖结构,提高手术的安全性。  相似文献   
32.
We present six cases which illustrate the spectrum of clinical features, macroscopic findings and light microscopic findings of urine extravasation from the upper urinary tract. The early lesions are characterized macroscopically by an oedematous, glistening or gelatinous appearance to the renal perihilar and peripelvic fat. Light microscopically there is lipolysis with associated foamy macrophages, multinucleate giant cells and lymphocytes. Immunohistochemical staining for Tamm–Horsfall protein is strongly positive in the extracellular space and in the foamy macrophages confirming urine extravazation. Later lesions are characterized by cicatrization of fibrous tissue around the renal pelvis and hydronephrosis. Microscopically there is relatively bland fibrosis with occasional lymphocytes and histiocytic cells. The late lesions are also characterized by extracellular deposits of weakly eosinophilic, granular or hyaline material, the so called 'urinary precipitates'. These deposits stain strongly with diastase PAS and weakly positive for Tamm–Horsfall protein. The staining of these urinary precipitates is analogous to renal tubular hyaline casts, thus supporting the theory that they are derived from uroproteins. We consider that these deposits are pathognomic of past urine extravasation.  相似文献   
33.
To make a preliminary assessment of whether upper limb soft tissue disorders might be associated with activities at work, we have conducted a case-control study of subjects attending orthopedic clinics in three cities. All subjects between the ages of 16 and 65 years, in whom defined soft tissue conditions of the upper limb were diagnosed by the participating orthopedic surgeons, were invited to take part. Controls were subjects attending the same clinics within the same age range whose clinical diagnosis did not include disease of the upper limb, cervical or thoracic spine. Information concerning repetitive movements of the upper limbs at work was elicited by questionnaire. Five hundred eighty cases and 996 controls were studied, representing 96% and 93%, respectively, of those invited to participate. The diagnoses of the cases included soft tissue conditions affecting the shoulder, elbow, forearm, wrist, thumb, hand, and fingers. The diagnoses of the controls included traumatic, degenerative, and inflammatory conditions, mostly of the legs and lower back. Women predominated among the cases (70%) and men among the controls (56%). Of 221 female cases with injury to the wrist and forearm, 32 were cleaner/domestics (14.5%) compared to 35 of 439 controls (8%), a difference statistically significant at the 2 1/2% level. Other jobs significantly overrepresented (5% level) among female cases with injuries at various anatomical sites included hairdressers, secretary/temps, assembly line workers, and machine operators (type unspecified). Among male cases, electricians were significantly overrepresented (5% level). Jobs for which there was a suggestion (p < 0.1) of overrepresentation among cases included butchers and teacher/ lecturers (both males only) and the combined job groups (chosen a priori for analysis) of keyboard operators, machine operators, and music teachers (all three jobs, females only).  相似文献   
34.
On-site testing of 157 poultry processors disclosed that 50% had three or more abnormal upper extremity findings out of a total of 22 possibles. The average worker had five to six abnormal findings. Impaired pinch strength, decreased vibration sensitivity in the fingertips, and reports of current numbness were the most prevalent. Of workers with signs, 25% reported no symptoms, whereas only 8% of workers reported symptoms but had no signs. The investigators concluded that this measurement method has utility for assessments of worker populations to determine prevalence of CTDs and, potentially, for preclinical detection of these disorders to permit early intervention, reduce medical costs, and minimize disability. The need for accurate measurement to enhance early detection and prevention is discussed.  相似文献   
35.
AIM: The aim of the present study was to investigate the safety and efficacy of endoscopic laser therapy for transitional cell carcinoma (TCC) of the upper urinary tract. METHODS: Tumors of the renal pelvis and ureteropelvic junction were detected by ureteroscopy. The tumors were subjected to biopsy, and after TCC was diagnosed, endoscopic laser therapy (Neodymium-YAG and Holmium-YAG) was conducted using a 6.9 Fr. flexible ureterorenoscope. RESULTS: From January 1997 to April 2002, six patients underwent ureteroscopic treatment. Tumor grade was 1 in four patients and 2 in two patients. Average tumor size was 1.45 cm. Endoscopic treatment was chosen for two patients because of the high medical risk associated with open surgery. Another patient underwent diagnostic ureteroscopy, followed immediately by endoscopic treatment. A further three patients elected to undergo ureteroscopic treatment. One patient with large (3 cm), multifocal and incompletely treated tumors died of metastatic disease 22 months after the initial operation. One patient requested nephroureterectomy one month after endoscopic treatment, and pathological examination of the resected specimen revealed no tumor. The other four patients have been followed up for a mean period of 14 months after initial treatment. Recurrence occurred in one patient, and was successfully treated by repeat endoscopic resection. None of the patients required blood transfusion or emergency open surgery. CONCLUSION: Ureteroscopic treatment of small, localized, low-grade TCC of the upper urinary tract is now a safe and feasible alternative to nephroureterectomy in selected patients.  相似文献   
36.
Abstract: The influence of endoscopic examination on the occurrence of arrhythmia was investigated electrocardiographically in 30 patients with cardiovascular disease who underwent transesophageal echocardiography (TEE) (group A) and 38 patients with digestive tract disease who underwent upper gastrointestinal endoscopy (UGIE) (group B). The mode and frequency of arrhythmia during the examination were compared between the two groups. (1) Arrhythmia was more frequently observed in group A (22 of 30, 73.3%) than in group B (9 of 38, 23.7%) patients (p<0.001). The common arrhythmias in both groups were supraventricular premature beat and ventricular premature beat. Serious arrhythmias, such as 2nd degree atrioventricular block and ventricular fibrillation were detected only in group A patients. (2) The region of the esophagus where the tip of the probe or scope was located was classified into three segments: upper (0–15 cm), middle (15–35 cm) and lower (35 cm<). Arrhythmias tended to be frequent when the tip of the probe or scope was located in the middle segment of the esophagus. These data indicate that arrhythmias observed during TEE or UGIE are related to the underlying heart disease. Furthermore, the middle segment of the esophagus appears to be particularly susceptible to the provocation of arrhythmia.  相似文献   
37.
Objective: Right upper lobe collapse is a common radiographic finding in intubated children. We hypothesized that deep suctioning and uncontrolled negative pressures during endotracheal tube suctioning were significant contributory factors. Methods : The incidence of right upper lobe (RUL) collapse in intubated, ventilated children on a paediatric cardiac intensive care unit was determined over a 3-month period ( n = 102). Graduated suction catheters and suction vacuums of < 165 cm H2O were then introduced. Another prospective audit was carried out 3 months later ( n = 60). Results : We found that 24% developed RUL collapse and 4 developed an apical pneumothorax. Following the introduction of graduated catheters and controlled vacuums pressures, a significant reduction in the incidence of RUL collapse, to 7%, was observed ( p < 0.05). Conclusions : We conclude that high negative pressure and deep-suctioning causes RUL collapse in children. Any lobar collapse not only prolongs the child's stay in intensive care, but can be associated with further morbidity which may have a serious implication. By improving suctioning technique this morbidity can be significantly reduced.  相似文献   
38.
<正>上交叉综合征(upper crossed syndrome,UCS)是指因上半身长期处于不良姿势,造成相关肌群功能失衡,进而引起颈肩背部疼痛不适、胸闷、睡眠障碍等一系列不良症状的一种亚健康状态[1]。UCS常见的体态是圆肩、驼背、头前倾[2]。目前临床上主要通过纠正局部的肌肉失衡来治疗UCS,常用的方法有运动疗法、肌肉能量技术、针灸和推拿等[3]。  相似文献   
39.
This article reviews recent studies on the importance of glycine receptors for both the spontaneous and the reflex respiratory modulation of the laryngeal abductors and adductors. Our findings show that strychnine blockade of glycine receptors within the brainstem changes the eupneic three-phase respiratory pattern into two phases. This has major implications for glottal control: (i) the inspiratory glottic abduction and early expiratory adduction were both compromised--a finding mimicked by 5% hypoxia; (ii) closure of the glottis during defensive upper airway reflexes became intermittent and the reflex apnoea reversed to sustained inspiratory discharge. Based on these data, we predict that periods of prolonged hypoxia, such as those that occur during sleep apnoeas, will constrain inspiratory glottic abduction thereby impeding inhalation.  相似文献   
40.
Clostridium difficile infection (CDI) remains a major public health issue, and fecal microbiota transplantation (FMT) has become one of the standard therapies for recurrent or refractory CDI. When compared to medical therapies, such as metronidazole or vancomycin, FMT has a high rate of treatment response with acceptable safety and efficiency. Following promulgation of the amendments in September 2018 in Taiwan, FMT has been indicated for recurrent or refractory CDI. The Taiwan Microbiota Consortium contributed to the Taiwan FMT Expert Consensus, which established basic norms and stipulated essential principles, including the indications for transplantation, eligible locations and personnel, donor screening policies, fecal sample handling, and post-FMT follow-up. However, establishing an eligible FMT team in a qualified hospital remains a clinical challenge, and the requirement for facilities and well-screened donors impedes the implementation of FMT. In this review, we aim to provide domestic FMT teams with explicit instructions to facilitate realization and increase the practice of FMT. Based on the Taiwan FMT Expert Consensus and current regulations, we performed a literature review and integrated the experiences of Taiwanese multidisciplinary experts into this article. The content intends to offer clinicians up-to-date evidence and highlight the essential points of FMT.  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