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   676篇
  免费   41篇
  国内免费   2篇
耳鼻咽喉   6篇
儿科学   20篇
妇产科学   16篇
基础医学   73篇
口腔科学   53篇
临床医学   52篇
内科学   144篇
皮肤病学   11篇
神经病学   24篇
特种医学   18篇
外科学   82篇
综合类   8篇
预防医学   79篇
眼科学   18篇
药学   70篇
中国医学   7篇
肿瘤学   38篇
  2023年   9篇
  2022年   17篇
  2021年   18篇
  2020年   17篇
  2019年   24篇
  2018年   35篇
  2017年   14篇
  2016年   27篇
  2015年   22篇
  2014年   40篇
  2013年   45篇
  2012年   51篇
  2011年   68篇
  2010年   31篇
  2009年   26篇
  2008年   31篇
  2007年   44篇
  2006年   25篇
  2005年   27篇
  2004年   24篇
  2003年   17篇
  2002年   15篇
  2001年   4篇
  2000年   11篇
  1999年   8篇
  1998年   5篇
  1997年   4篇
  1995年   4篇
  1994年   2篇
  1992年   3篇
  1991年   2篇
  1990年   6篇
  1989年   5篇
  1988年   4篇
  1987年   3篇
  1986年   3篇
  1985年   5篇
  1984年   5篇
  1983年   4篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
  1974年   1篇
  1973年   1篇
  1971年   1篇
  1970年   1篇
  1969年   1篇
  1968年   1篇
  1967年   2篇
  1966年   1篇
排序方式: 共有719条查询结果,搜索用时 15 毫秒
41.
42.
Increasingly, it is recognised by health planners and social scientists that self medication with drugs bought over the counter in private pharmacies is extremely widespread. Some anthropologists see this trend as an aspect of the 'commodification of health'. In this study, group interviews with health service users and providers in Gaza revealed many health service users reporting an inadequate supply of drugs resulting in the purchasing of drugs in private pharmacies. As a result, a survey of the pattern of utilization of three private pharmacies in three contrasting urban areas within the Gaza Strip was undertaken. Using a questionnaire, data were collected from all customers buying drugs. The results show that variations in the patterns of health seeking behaviour were associated with socioeconomic status. Adult males were the most frequent customers of all three pharmacies. They were buying medicines for members of their nuclear family more often than for themselves. Overall, pain and influenza were the most commonly reported conditions. The drugs purchased most frequently for women were for reproductive health problems, particularly infertility. Customers of the pharmacy in the relatively prosperous area more commonly purchased drugs which were prescribed by a private doctor.  相似文献   
43.
Annals of Biomedical Engineering - Unlike the central nervous system, the peripheral nervous system (PNS) has an inherent capacity to regenerate following injury. However, in the case of large...  相似文献   
44.

Background

As the field of minimally invasive surgery continues to develop, surgeons are confronted with the challenge of performing conventional laparoscopic surgeries through fewer incisions while maintaining the same degree of safety and surgical efficiency. Most of these methods involve elimination of the ports previously designated for retraction. As a result, minimally invasive surgeons have been forced to develop minimally invasive and ingenious methods for providing adequate retraction for these procedures. Herein we present our experience using endoloops and internal retractors to provide retraction during Single Incision Minimally Invasive Surgery (SIMIS) and Natural Orifice Transluminal Endoscopic Surgery (NOTES) cholecystectomy. We also present a review of the alternative retraction methods currently being employed for these surgeries.

Methods

SIMIS was performed on 20 patients and NOTES was performed on 5 patients at our institution. Endoloops or internal retractors were used to provide retraction for all SIMIS procedures. Internal retractors provided retraction for all NOTES procedures.

Results

Successful cholecystectomy was accomplished in all cases. One SIMIS surgery required conversion to standard laparoscopy due to complex anatomy. There were no intraoperative complications. Although adequate retraction was accomplished in all cases, the internal retractors were found to provide superior and more versatile retraction compared to that of endoloops.

Conclusion

Adequate retraction greatly simplifies SIMIS and NOTES surgery. Endograb internal retractors were easy to use and were found to provide optimal retraction and exposure during these procedures without complications.  相似文献   
45.
A 34 year-old male with multiple lithiasis of ectopic pelvic left kidney, which for 5 years had been causing pain in the left iliac region irradiating to ipsilateral inguinal region and testis. 4 ESWL treatments were unsuccessful. The diagnostic imaging (Angio-CT + Uro-CT) showed ectopic pelvic left kidney with abnormal vascularisation, characterised by multiple lithiasis extending in total area of 4x2 cm with shorter ureter. Right kidney was in normal position. A left pyelocalicolithotomy after DJ stent positioning was performed.  相似文献   
46.
The idea that the environmental toxin beta-N-methylamino-l-alanine (BMAA) is involved in neurodegenerative diseases on Guam has risen and fallen over the years. The theory has gained greater interest with recent reports that BMAA is biomagnified, is widely distributed around the planet, and is present in the brains of Alzheimer's patients in Canada. We provide two important new findings. First, we show that BMAA at concentrations as low as 10 muM can potentiate neuronal injury induced by other insults. This is the first evidence that BMAA at concentrations below the mM range can enhance death of cortical neurons and illustrates potential synergistic effects of environmental toxins with underlying neurological conditions. Second, we show that the mechanism of BMAA toxicity is threefold: it is an agonist for NMDA and mGluR5 receptors, and induces oxidative stress. The results provide further support for the hypothesis that BMAA plays a role in neurodegenerative diseases.  相似文献   
47.
48.
Objective: To test the hypothesis that the use of a combination headgear (HG) during the first phase of orthodontic treatment has no effect on the eruption pattern of the maxillary second permanent molars.Materials and Methods:The records of the patients in a two-phase randomized clinical trial of early Class II treatment were utilized. The HG group comprised 47 patients, and the control (CON) group comprised 52 patients. The mean age of both groups was 9.4 years at the beginning of the clinical trial (T1). Cephalograms and panoramic views obtained at T1 and at the end of 15 months of phase I treatment or observation (T2) were utilized. The vertical and horizontal movements of the first and second upper molars (U6 and U7, respectively) were measured. The beginning of phase II (T3) and the end of phase II (T4) records were visually reviewed for follow-up of the eruption of the U7.Results:The pattern of movement for the distal and vertical displacement of the U6 and U7 was significantly different in the HG and CON groups (P < .001). At the end of phase I, none of the U7 in either group were diagnosed as malposed or suspected for impaction. At the end of phase II, all but one U7 with a possible cystic lesion had erupted.Conclusions:The hypothesis is rejected. Forces exerted by combination headgear to the U6 in phase I have a distalizing effect and a transitory slowing down effect on the eruption of the U7 buds. These latter teeth always erupted except when pathology occurred.  相似文献   
49.
Umbilical pilonidal sinus is a cause of umbilical discharge. In this study, the outcome of complete excision of the umbilical sinus with umbilical reconstruction is considered. Adult patients with umbilical pilonidal sinus who had not undergone any previous surgeries were operated on using a technique that involves complete excision of the sinus after eversion of the umbilicus followed by reconstruction of the umbilicus. Patients were then followed; and wound complications, recurrence, and patient satisfaction were evaluated at postoperative visits. A total of 45 patients underwent the operation; 39 (86.5%) were male, and 6 (13.5%) were female. The mean age was 22.6 years (18-27 years). Six male patients had synchronous sacrococcygeal pilonidal disease. The mean follow-up period was 34 months (3-62 months). Only four patients had wound drainage after operation, and all required drainage of the wound. No recurrence was observed during the follow-up period, and all patients were satisfied with the appearance of their umbilicus. The technique of complete sinus excision and umbilical reconstruction is an effective and acceptable method for treating umbilical pilonidal sinus and may be recommended for primary treatment of this disease.  相似文献   
50.
BACKGROUND: The mental foramen is frequently encountered in a number of maxillofacial surgical procedures. Its position has been shown to vary according to race. The aim was to study the position, shape, and appearance of the mental foramen, as seen on panoramic radiographs of Jordanians, and to compare our findings with international values. PATIENTS AND METHODS: Panoramic radiographs were randomly selected from the records of dental patients attending three dental services, and were analyzed according to patients' age and gender, and the mental foramina's anterior-posterior and superior-inferior positions, shape, appearance, and symmetry. RESULTS: There were 860 cases (1,720 sides) with a female-to-male ratio of 1:1.4, and mean age of 24. The most frequent anterior-posterior position was in the area between the long axes of first and second mandibular premolar teeth. With advancing age, there was an increase in the frequency of more posterior positioning. The anterior-posterior position was asymmetrical in 33% of cases. The most frequent superior-inferior position was below the level of apices of mandibular premolar teeth roots. With advancing age there was an increase in the frequency of more inferior positioning. The superior-inferior position was asymmetrical in 14% of cases. The majority of foramina were round in shape, and the most frequent appearance was the continuous type. Accessory mental foramina were seen in 10% of the cases. CONCLUSION: The position of the mental foramen on panoramic radiographs in this selected group of Jordanians is most commonly below and between the mandibular premolar teeth, and the most frequent appearance was the continuous type. These results are similar to previous findings in Caucasian populations.  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