全文获取类型
收费全文 | 6263篇 |
免费 | 386篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 175篇 |
儿科学 | 399篇 |
妇产科学 | 67篇 |
基础医学 | 661篇 |
口腔科学 | 78篇 |
临床医学 | 485篇 |
内科学 | 1417篇 |
皮肤病学 | 140篇 |
神经病学 | 489篇 |
特种医学 | 188篇 |
外科学 | 1062篇 |
综合类 | 58篇 |
一般理论 | 2篇 |
预防医学 | 466篇 |
眼科学 | 103篇 |
药学 | 383篇 |
中国医学 | 5篇 |
肿瘤学 | 486篇 |
出版年
2023年 | 35篇 |
2022年 | 70篇 |
2021年 | 201篇 |
2020年 | 117篇 |
2019年 | 170篇 |
2018年 | 227篇 |
2017年 | 173篇 |
2016年 | 176篇 |
2015年 | 205篇 |
2014年 | 302篇 |
2013年 | 340篇 |
2012年 | 477篇 |
2011年 | 485篇 |
2010年 | 250篇 |
2009年 | 214篇 |
2008年 | 391篇 |
2007年 | 377篇 |
2006年 | 339篇 |
2005年 | 282篇 |
2004年 | 275篇 |
2003年 | 274篇 |
2002年 | 210篇 |
2001年 | 78篇 |
2000年 | 68篇 |
1999年 | 76篇 |
1998年 | 49篇 |
1997年 | 47篇 |
1996年 | 49篇 |
1995年 | 34篇 |
1994年 | 26篇 |
1993年 | 23篇 |
1992年 | 39篇 |
1991年 | 36篇 |
1990年 | 38篇 |
1989年 | 33篇 |
1988年 | 46篇 |
1987年 | 32篇 |
1986年 | 37篇 |
1985年 | 32篇 |
1984年 | 19篇 |
1983年 | 24篇 |
1982年 | 26篇 |
1981年 | 24篇 |
1980年 | 17篇 |
1979年 | 21篇 |
1978年 | 20篇 |
1977年 | 17篇 |
1976年 | 19篇 |
1973年 | 23篇 |
1972年 | 19篇 |
排序方式: 共有6664条查询结果,搜索用时 15 毫秒
51.
Sahai A Cortes E Seth J Khan MS Panicker J Kelleher C Kessler TM Fowler CJ Dasgupta P 《Current urology reports》2011,12(6):404-412
Lower urinary tract dysfunction can have a significant impact on patients with spinal cord injury. Over the years, many treatment
options have become available. This article reviews the assessment and management of neurogenic detrusor overactivity, with
a particular focus on articles from the recent literature. Recent guidelines on the subject will be discussed. Management
options include antimuscarinics and bladder emptying measures, botulinum toxin A, and neuromodulation in refractory cases
and surgery for intractable cases. Recent and relevant publications in these areas will be summarized and discussed. 相似文献
52.
Cerebrospinal fluid (CSF) leak closure remains one of the most difficult surgeries for skull base surgeons, particularly with frontal sinus involvement. Technological advances in endoscopic surgery increasingly allow for less morbid approaches to the frontal sinus. We describe a series of patients who underwent endoscopic frontal sinus CSF leak repair utilizing a unilateral approach, to evaluate the utility and outcomes of this method. We performed a retrospective review of four cases in tertiary care centers. Participants included patients with CSF leak involving the frontal sinus. Main outcome measures included cessation of CSF leak and frontal sinus patency. Three patients were closed on the first surgical attempt; one with a communicating hydrocephalus required a revision procedure. Leak etiologies included prior craniotomy for frontal sinus mucopyocele, spontaneous meningoencephalocele, erosion due to mucormycosis, and prior endoscopic sinus surgery. The frontal sinus remained patent in three of four patients. No patients have evidence of a leak at a minimum of 1 year after surgery. The repair of frontal sinus CSF leaks is possible in specific cases with an endoscopic unilateral approach in leaks with multiple etiologies. Surgeons should consider this approach when selecting the appropriate procedure for repair of frontal sinus CSF leaks. 相似文献
53.
In total knee arthroplasty (TKA), intramedullary and extramedullary tibial alignment guides are not proven to be highly accurate in obtaining alignment perpendicular to the mechanical axis in the coronal plane. The objective of this study was to determine the accuracy of an accelerometer-based, handheld surgical navigation system in obtaining a postoperative tibial component alignment within 2° of the intraoperative goal in both the coronal and sagittal planes. A total of 151 TKAs were performed by 2 surgeons using a handheld surgical navigation system to perform the tibial resection. Postoperatively, standing anteroposterior hip-to-ankle radiographs and lateral knee-to-ankle radiographs were performed to determine the varus/valgus alignment and the posterior slope of the tibial components relative to the mechanical axis in both the coronal and sagittal planes. Findings showed that 95.3% of the tibial components were placed within 2° of the intraoperative goal in the coronal plane and 96.1% of the components were placed within 2° of the intraoperative goal in the sagittal plane. Overall, mean postoperative lower-extremity alignment was -0.3°±2.1°, with 97% of patients having an alignment within 3° of a neutral mechanical axis. The handheld surgical navigation system improves the accuracy of the tibial resection and subsequent tibial component alignment in TKA. It is able to combine the accuracy of computer-assisted surgery systems with the ease of use and familiarity of conventional, extramedullary alignment systems, and the ability to adjust both the coronal and sagittal alignments intraoperatively may prove clinically useful in TKA. 相似文献
54.
Nam D Jerabek SA Haughom B Cross MB Reinhardt KR Mayman DJ 《The Journal of arthroplasty》2011,26(8):1527-1533
Tibial intramedullary or extramedullary alignment guides have not been shown to be highly accurate in performing the tibial resection in total knee arthroplasty (TKA). Since May 2010, a total of 42 knees underwent a TKA using a hand-held, accelerometer-based surgical navigation system for performing the tibial resection (KneeAlign; OrthAlign Inc, Aliso Viejo, Calif). Postoperative standing anteroposterior hip-to-ankle and lateral knee-to-ankle radiographs demonstrated that 97.6% of the tibial components were placed within 90° ± 2° to the mechanical axis in the coronal plane, and 96.2% of the components were placed within 3° ± 2° to the mechanical axis in the sagittal plane. The KneeAlign greatly improves the accuracy of tibial component alignment in TKA. 相似文献
55.
Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and subsequently recover it at a faster rate than other animals. Here we show decreased cortical bone turnover during hibernation with balanced formation and resorption in grizzly bear femurs. Hibernating grizzly bear femurs were less porous and more mineralized, and did not demonstrate any changes in cortical bone geometry or whole bone mechanical properties compared to active grizzly bear femurs. The activation frequency of intracortical remodeling was 75% lower during hibernation than during periods of physical activity, but the normalized mineral apposition rate was unchanged. These data indicate that bone turnover decreases during hibernation, but osteons continue to refill at normal rates. There were no changes in regional variation of porosity, geometry, or remodeling indices in femurs from hibernating bears, indicating that hibernation did not preferentially affect one region of the cortex. Thus, grizzly bears prevent bone loss during disuse by decreasing bone turnover and maintaining balanced formation and resorption, which preserves bone structure and strength. These results support the idea that bears possess a biological mechanism to prevent disuse osteoporosis. 相似文献
56.
The objective of this study was to maximize the success rate of sentinel node (SN) localization in breast cancer patients with the tracer that demonstrated the highest initial success during a preliminary evaluation. Altogether, 145 patients with operable invasive breast cancer and clinically negative lymph nodes were studied. Technetium 99m (99mTc)-sulfur colloid was injected into the breast parenchyma surrounding the invasive cancer or the biopsy cavity. Variable volumes of tracer, amounts of 99mTc, and duration of time between injection and surgery were evaluated. A hand-held gamma detector was used at surgery to locate and guide resection of all radioactive sentinel nodes (SNs), including those that were extraaxillary. A conventional lymphadenectomy was then performed in all cases. Based on previous studies, unfiltered sulfur colloid provided a higher success rate of SN identification than the other tracer types. Further evaluation with 99mTc-sulfur colloid demonstrated that increased volume increased the success rate of SN identification. An injection volume of 8 ml resulted in a success rate of 98%. SNs were not exclusively located in the axilla: In 8.6% of cases SNs were removed from an internal mammary location. The overall accuracy of patients with SNs resected was 98.4%, and the false-negative rate was 4.4%. It was concluded that (1) unfiltered 99mTc-sulfur colloid at a volume of 8 ml resulted in a high success rate for SN identification; (2) a significant number of the SNs were extraaxillary in location; and (3) the accuracy of the SNs for determining whether regional metastases had occurred was high. The U.S. National Cancer Institute is funding a randomized phase III clinical trial to evaluate SN resection compared to conventional axillary lymphadenectomy in clinical node-negative breast cancer patients. Major endpoints of this trial include long-term regional control and survival. 相似文献
57.
Age affects outcomes in chronic kidney disease 总被引:1,自引:0,他引:1
O'Hare AM Choi AI Bertenthal D Bacchetti P Garg AX Kaufman JS Walter LC Mehta KM Steinman MA Allon M McClellan WM Landefeld CS 《Journal of the American Society of Nephrology : JASN》2007,18(10):2758-2765
Chronic kidney disease (CKD) is common among the elderly. However, little is known about how the clinical implications of CKD vary with age. We examined the age-specific incidence of death, treated end-stage renal disease (ESRD), and change in estimated glomerular filtration rate (eGFR) among 209,622 US veterans with CKD stages 3 to 5 followed for a mean of 3.2 years. Patients aged 75 years or older at baseline comprised 47% of the overall cohort and accounted for 28% of the 9227 cases of ESRD that occurred during follow-up. Among patients of all ages, rates of both death and ESRD were inversely related to eGFR at baseline. However, among those with comparable levels of eGFR, older patients had higher rates of death and lower rates of ESRD than younger patients. Consequently, the level of eGFR below which the risk of ESRD exceeded the risk of death varied by age, ranging from 45 ml/min per 1.73 m(2) for 18 to 44 year old patients to 15 ml/min per 1.73 m(2) for 65 to 84 year old patients. Among those 85 years or older, the risk of death always exceeded the risk of ESRD in this cohort. Among patients with eGFR levels <45 ml/min per 1.73 m(2) at baseline, older patients were less likely than their younger counterparts to experience an annual decline in eGFR of >3 ml/min per 1.73 m(2). In conclusion, age is a major effect modifier among patients with an eGFR of <60 ml/min per 1.73 m(2), challenging us to move beyond a uniform stage-based approach to managing CKD. 相似文献
58.
59.