全文获取类型
收费全文 | 157410篇 |
免费 | 10678篇 |
国内免费 | 1198篇 |
专业分类
耳鼻咽喉 | 2228篇 |
儿科学 | 2998篇 |
妇产科学 | 3740篇 |
基础医学 | 23416篇 |
口腔科学 | 3321篇 |
临床医学 | 14864篇 |
内科学 | 29672篇 |
皮肤病学 | 4280篇 |
神经病学 | 11821篇 |
特种医学 | 7982篇 |
外科学 | 21728篇 |
综合类 | 2111篇 |
现状与发展 | 5篇 |
一般理论 | 81篇 |
预防医学 | 9312篇 |
眼科学 | 4252篇 |
药学 | 13483篇 |
中国医学 | 1587篇 |
肿瘤学 | 12405篇 |
出版年
2023年 | 757篇 |
2022年 | 617篇 |
2021年 | 4075篇 |
2020年 | 2482篇 |
2019年 | 3586篇 |
2018年 | 4405篇 |
2017年 | 3233篇 |
2016年 | 4189篇 |
2015年 | 5639篇 |
2014年 | 6907篇 |
2013年 | 8372篇 |
2012年 | 12653篇 |
2011年 | 12285篇 |
2010年 | 7255篇 |
2009年 | 6067篇 |
2008年 | 9259篇 |
2007年 | 9123篇 |
2006年 | 8388篇 |
2005年 | 7991篇 |
2004年 | 7120篇 |
2003年 | 6185篇 |
2002年 | 5356篇 |
2001年 | 4363篇 |
2000年 | 4001篇 |
1999年 | 3217篇 |
1998年 | 1193篇 |
1997年 | 875篇 |
1996年 | 856篇 |
1995年 | 853篇 |
1994年 | 741篇 |
1993年 | 632篇 |
1992年 | 1566篇 |
1991年 | 1569篇 |
1990年 | 1349篇 |
1989年 | 1233篇 |
1988年 | 1150篇 |
1987年 | 1030篇 |
1986年 | 1006篇 |
1985年 | 880篇 |
1984年 | 642篇 |
1983年 | 560篇 |
1982年 | 392篇 |
1981年 | 374篇 |
1980年 | 336篇 |
1979年 | 514篇 |
1978年 | 402篇 |
1977年 | 384篇 |
1976年 | 340篇 |
1974年 | 356篇 |
1973年 | 325篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
991.
Obesity and osteoporosis are two important body composition problems with increasing prevalences in aged populations. Traditionally, obesity has been regarded as being beneficial to bone health. However, the protective effect of obesity on osteoporosis has been questioned. In some recent studies, obesity, as defined by percentage body fat, was regarded as a risk factor for osteoporosis. The purpose of this study was to (1) evaluate the effect of waist circumference, a surrogate measure for abdominal obesity, on bone mineral content (BMC) and (2) examine whether the effect of waist circumference increases with advancing age. The study population is made up of women aged over 45 years who completed the body composition and bone mineral density examinations in the fifth Korea National Health and Nutrition Examination Survey in 2010. Subjects who take estrogen or are under medical treatment for osteoporosis were excluded. Stroke patients are also excluded. Femoral neck, total-hip, and whole-body BMC were measured by dual-energy X-ray absorptiometry. A total of 1,434 subjects were included in the analysis. Waist circumference was negatively associated with BMC in all tested regions after correction for weight, menopausal status, smoking, drinking, and exercise. In addition, the negative association between waist circumference and BMC in the femoral neck and total hip increases with age, after correction for confounding factors, showing an interaction effect between waist circumference and age on BMC. In conclusion, this study shows that the negative relationship between waist circumference and BMC in the femoral neck and total hip is greater for older women. 相似文献
992.
Kyung Shik Lee Ji Su Jang Dong Ryul Lee Yang Hyun Kim Ga Eun Nam Byoung-duck Han Kyung Do Han Kyung Hwan Cho Seon Mee Kim Youn Seon Choi Do Hoon Kim 《Journal of bone and mineral metabolism》2014,32(6):683-690
A possible negative effect of iron overload on bone metabolism has been suggested by the fact that patients with hemochromatosis, thalassemia, and sickle cell anemia have lower bone mineral density than the general population. However, the influence of iron overload on bone health in the general population is uncertain. The aim of this study was to investigate the relationship between serum ferritin levels and bone mineral density (BMD) in elderly Koreans. A total of 2,943 subjects aged 65 years and over who participated in the 2008–2010 Korea National Health and Nutrition Examination Surveys were included in this study. Age, physical activity, current smoking status, alcohol consumption, education level, household income, and dietary assessment were surveyed by a face-to-face interview. BMD was measured at the lumbar spine and femur by dual-energy X-ray absorptiometry, and other biochemical markers, including serum ferritin, 25-hydroxyvitamin D3, serum alkaline phosphatase, and parathyroid hormone, were assayed. After adjusting for age and body mass index, we found an association between BMD of the total lumbar spine, total femur, and femur neck and levels of alkaline phosphatase, parathyroid hormone, vitamin D3, and daily intake of calcium and protein. Serum ferritin levels were positively associated with BMD of the total lumbar spine, total femur, and femur neck after adjusting for all covariates in men, but not in women. This study suggests a positive association between serum ferritin levels and BMD in elderly South Korean men without hematologic disorders. Further study is warranted to verify the effects of iron on bone metabolism. 相似文献
993.
Sunmin Park Chung-Yill Park Jung-O Ham Byung-Kook Lee 《Journal of bone and mineral metabolism》2014,32(4):455-467
We examined familial bone mineral density (BMD) interactions between parents and children and lifestyle factors affecting BMD in the Korean general population of children under 20 and parents under 50 years of age. This cross-sectional study included 2,453 participants (667 daughters, 705 sons, 719 mothers, and 362 fathers) in the 2009–2010 Korean National Health and Nutrition Examination Survey. We calculated prevalence ratios and 95 % confidence intervals for BMD values of whole femur, femur neck, lumbar spine, and whole body excluding the head being in the low tertile in adolescents according to parental BMD tertile after adjusting for physical, lifestyle, and dietary factors. For daughters and sons, there were significant differences in BMD at the four bone sites according to age group, body fat percentage, regular walking and exercise, and milk consumption compared to the reference value for each classification category. Surprisingly, there were no differences in BMD according to serum 25-OH-D levels. Birth order affected BMD of only whole body except head, but its impact was less than that of lifestyle factors. The mean differences in BMD between daughters and sons in the first and third parental BMD tertiles were statistically significant. Notably, the prevalence ratio of whole body without head BMD being in the low tertile increased eight and ten-folds in adolescent daughters and sons, respectively, when parents were in the low BMD tertile. In specific bone regions, parental BMD had a greater effect on total femur in daughters but in the lumbar spine in sons. In conclusion, parental BMD positively influences BMD in daughters and sons after adjustment for environmental parameters. This suggests that the children from parents with low BMD need to make an extra effort to increase BMD through dietary and lifestyle changes. 相似文献
994.
Objective
To assess the possibility of using single-port low anterior resection (LAR) in place of conventional laparoscopic LAR.Background
Though single-port LS is gradually evolving, the application of single-port LS techniques in LAR have been viewed with skepticism due to technical difficulties.Methods
Data from patients who had undergone either conventional laparoscopic LAR (n = 49) or single-port LAR (n = 67) for colorectal cancers between March 2006 and March 2013 were analyzed retrospectively.Results
In single-port LAR group, oncologic outcomes were satisfactory with respect to attainment of lymph nodes (23.4 ± 15.3) and surgical margins (proximal cut margin: 7.1 ± 4.6 cm, distal cut margin: 7.7 ± 5.7 cm). Single-port LAR showed acceptable clinical outcomes manifested by comparable outcomes of post-operative analgesics requirement and length of hospital stay, and by low incidence of post-operative complications (conventional laparoscopic LAR group: 30.6 % vs. single-port LAR group: 14.9 %; P < 0.01). Operative time was comparable between groups (conventional laparoscopic LAR group: 309 ± 93 min vs. single-port LAR group: 277 ± 106 min; P = 0.097). Throughout a series of 67 consecutive single-port LARs, no conversion to multiport or open surgery was occurred.Conclusion
This study shows that single-port LAR is both safe and feasible for use in resection of colorectal cancer when performed by surgeons who are trained in conventional laparoscopic technique. If further and more extensive studies support our results, then single-port LAR can be an acceptable alternative to conventional laparoscopic LAR for treatment of colorectal cancer. 相似文献995.
Ahmed Sharata Ashwin A. Kurian Christy M. Dunst Neil H. Bhayani Kevin M. Reavis Lee L. Swanstrom 《Surgical endoscopy》2014,28(4):1333-1333
Background
Per-Oral Endoscopic Myotomy (POEM) is becoming an acceptable alternative to laparoscopic cardiomyotomy for esophageal motility disorders. The aim of this video is to provide key technical steps to completing this procedure.Method
Each patient underwent diagnostic investigations including high resolution manometry (HRM), esophageogastroduodenoscopy (EGD), and timed-barium swallow for primary esophageal motility disorders preoperatively. Patients undergoing POEM procedures are preoperatively prepared by taking Nystatin swish-and-swallow for 3 days, 24 h of clear liquid diet, and 12 h of NPO. Preoperative antibiotics are given. Under general anesthesia and with the patient in the supine position, endoscopy with CO2 insufflation is prepared. Special endoscopic instruments and electrocautery settings are required to perform the POEM procedure, as illustrated in the slides. POEM is performed in six key/critical steps: (1) diagnostic endoscopy; (2) taking measurements; (3) esophageal mucosotomy creation; (4) submucosal tunneling; (5) selective circular myotomy of the anterior lower esophageal sphincter; and (6) closure of the mucosotomy. According to our protocol, all patients get an esophogram the next morning after surgery prior to discharge. The patient receives objective testing (HRM with 24 PH Impedance test, EGD, and timed-barium swallow) 6 months postoperatively.Conclusion
In six key steps, POEM can be accomplished as described in the video. 相似文献996.
Kit-fai Lee Ching-ning Chong Ka-wing Ma Eric Cheung John Wong Sunny Cheung Paul Lai 《Surgical endoscopy》2014,28(9):2690-2694
Background
Mirizzi syndrome (MS) is a rare complication of gallstone disease. Despite the fact that successful laparoscopic treatments have been reported, open surgery remains the gold standard approach for this disease due to technical difficulties involved.Methods
A minimally invasive strategy combining endoscopic retrograde cholangiopancreatography (ERCP) and robotic surgery for the management of MS was implemented in early 2012. This consisted of a preoperative ERCP for definitive diagnosis and endoscopic stent insertion. Robotic surgical approach was used during operation to facilitate gall bladder removal and suture of defect over common duct. ERCP was repeated postoperatively for stent removal. Patient demographics and treatment outcomes were collected prospectively. A historical cohort of patients with MS who underwent conventional surgery between 1999 and 2011 was identified for comparison of treatment outcomes.Results
Five patients with MS were managed with this strategy. Robotic subtotal cholecystectomy was successfully performed in all the patients without conversion or morbidity. When compared with a historical cohort of 17 patients who underwent surgery for MS, this group of patients had significantly less conversion and shorter hospital stay though the operation time was longer. It also showed less blood loss and less postoperative complications but these were not statistically significant.Conclusion
Mirizzi syndrome can be effectively managed with a minimally invasive approach by adopting a robot-assisted surgery together with a planned pre- and postoperative ERCP. 相似文献997.
Sohee Lee Cho Rok Lee Seung Chul Lee Seulkee Park Ha Yan Kim Haiyoung Son Sang-Wook Kang Jong Ju Jeong Kee-Hyun Nam Woong Youn Chung Cheong Soo Park Arthur Cho 《Surgical endoscopy》2014,28(4):1068-1075
Background
Using the da Vinci® robotic system, surgeons can complete secure thyroidectomy without noticeable neck scarring. This study compared the surgical completeness of transaxillary robotic thyroidectomy (RT) with conventional open procedures (OT) in treating papillary thyroid carcinoma (PTC) patients.Materials and methods
From April 2009 through February 2011, 94 PTC patients underwent total thyroidectomy with central compartment neck dissection (CCND) at Yonsei University College of Medicine. All patients received 1.1 GBq radioactive iodine (RAI) ablation, post-therapy whole-body scans (TxWBS), and diagnostic WBS (DxWBS) 1 year later. We prospectively compared patient clinicopathologic characteristics and surgical completeness between the two groups.Results
Fifty-one patients underwent OT and 43 underwent RT. Mean age was significantly younger in the RT group. Tumor size, capsular-invasion frequency, multifocality, bilaterality, and central nodal metastasis were not different between the two groups. The number of retrieved nodes during CCND did not significantly differ between the groups. There was no significant difference between the OT and RT groups in stimulated thyroglobulin levels acquired during TxWBS and DxWBS. The RAI uptake ratios at TxWBS were significantly higher in the RT group compared with the OT group; however, follow-up DxWBS showed no difference in RAI uptake ratios. Also, the ablation success rate was similar between the two groups. There were no abnormal findings in follow-up neck ultrasonography in either group.Conclusion
Remnant thyroid tissue ablation after transaxillary RT was successfully managed by 1.1 GBq RAI. RT showed similar surgical completeness versus conventional OT, and provides a safe and feasible surgical option for PTC patients. 相似文献998.
Karim A. Sarhane Saami Khalifian Zuhaib Ibrahim Damon S. Cooney Theresa Hautz Wei‐Ping Andrew Lee Stefan Schneeberger Gerald Brandacher 《Clinical transplantation》2014,28(3):277-285
Refinements in microsurgical techniques coupled with advances in immunosuppressive and immunomodulatory protocols have enabled broader clinical application of vascularized composite allotransplantation (VCA) with encouraging immunological, functional, and esthetic results. However, skin rejection remains a significant obstacle and a serious complication for VCA recipients. Clinical and histopathological features of rejection in VCA have been described in a number of studies, which led to the development of an international consensus on the classification guidelines of rejection in the context of VCA. Nevertheless, currently available diagnostic modalities still have several limitations and shortcomings that can pose a significant diagnostic challenge, particularly when signs of rejection are found to be equivocal. In this review, we provide a critical analysis of these advances and challenges in diagnosing skin rejection. Specifically, we highlight the gaps in understanding of rejection mechanisms, the shortfalls in correlating cellular, molecular, and clinicopathologic markers with rejection grades, deficiencies in defining chronic rejection, and antibody‐mediated rejection after VCA, as well as providing an outlook on novel concepts, such as the utilization of advanced computational analyses and cross‐disciplinary diagnostic approaches. 相似文献
999.
Lawrence Lee Juan Mata Tara Landry Kosar A. Khwaja Melina C. Vassiliou Gerald M. Fried Liane S. Feldman 《Surgical endoscopy》2014,28(9):2531-2546
Background
Guidelines recommend the use of bioprosthetics for abdominal wall reinforcement in contaminated fields, but the evidence supporting the use of biologic over synthetic non-absorbable prosthetics for this indication is poor. Therefore, the objective was to perform a systematic review of outcomes after synthetic non-absorbable and biologic prosthetics for ventral hernia repair or prophylaxis in contaminated fields.Methods
The systematic literature search identified all articles published up to 2013 that reported outcomes after abdominal wall reinforcement using synthetic non-absorbable or biologic prosthetics in contaminated fields. Studies were included if they included at least 10 cases (excluding inguinal and parastomal hernias). Quality assessment was performed using the MINORS instrument. The main outcomes measures were the incidence of wound infection and hernia at follow-up. Weighted pooled proportions were calculated using a random effects model.Results
A total of 32 studies met the inclusion criteria and were included for synthesis. Mean sample size was 41.4 (range 10–190), and duration of follow-up was >1 year in 72 % of studies. Overall quality was low (mean 6.2, range 1–12). Pooled wound infection rates were 31.6 % (95 % CI 14.5–48.7) with biologic and 6.4 % (95 % CI 3.4–9.4) with synthetic non-absorbable prosthetics in clean-contaminated cases, with similar hernia rates. In contaminated and/or dirty fields, wound infection rates were similar, but pooled hernia rates were 27.2 % (95 % CI 9.5–44.9) with biologic and 3.2 % (95 % CI 0.0–11.0) with synthetic non-absorbable. Other outcomes were comparable.Conclusions
The available evidence is limited, but does not support the superiority of biologic over synthetic non-absorbable prosthetics in contaminated fields. 相似文献1000.
Ji Min Choi Changhyun Lee Yoo Min Han Minjong Lee Young Hoon Choi Dong Kee Jang Jong Pil Im Sang Gyun Kim Joo Sung Kim Hyun Chae Jung 《Surgical endoscopy》2014,28(9):2649-2655