全文获取类型
收费全文 | 73560篇 |
免费 | 7678篇 |
国内免费 | 1976篇 |
专业分类
耳鼻咽喉 | 1474篇 |
儿科学 | 1467篇 |
妇产科学 | 2438篇 |
基础医学 | 8199篇 |
口腔科学 | 1473篇 |
临床医学 | 8457篇 |
内科学 | 14242篇 |
皮肤病学 | 1701篇 |
神经病学 | 5091篇 |
特种医学 | 3124篇 |
外国民族医学 | 6篇 |
外科学 | 11529篇 |
综合类 | 4223篇 |
现状与发展 | 9篇 |
一般理论 | 11篇 |
预防医学 | 4201篇 |
眼科学 | 1742篇 |
药学 | 5398篇 |
20篇 | |
中国医学 | 1676篇 |
肿瘤学 | 6733篇 |
出版年
2024年 | 147篇 |
2023年 | 965篇 |
2022年 | 1196篇 |
2021年 | 2434篇 |
2020年 | 2013篇 |
2019年 | 1821篇 |
2018年 | 2632篇 |
2017年 | 2124篇 |
2016年 | 2324篇 |
2015年 | 3005篇 |
2014年 | 3838篇 |
2013年 | 4428篇 |
2012年 | 5135篇 |
2011年 | 4954篇 |
2010年 | 3601篇 |
2009年 | 3448篇 |
2008年 | 3850篇 |
2007年 | 3728篇 |
2006年 | 3669篇 |
2005年 | 3289篇 |
2004年 | 2940篇 |
2003年 | 2801篇 |
2002年 | 2440篇 |
2001年 | 2014篇 |
2000年 | 1715篇 |
1999年 | 1504篇 |
1998年 | 801篇 |
1997年 | 723篇 |
1996年 | 732篇 |
1995年 | 661篇 |
1994年 | 525篇 |
1993年 | 370篇 |
1992年 | 837篇 |
1991年 | 712篇 |
1990年 | 600篇 |
1989年 | 609篇 |
1988年 | 519篇 |
1987年 | 500篇 |
1986年 | 441篇 |
1985年 | 381篇 |
1984年 | 315篇 |
1983年 | 260篇 |
1982年 | 188篇 |
1981年 | 171篇 |
1980年 | 152篇 |
1979年 | 234篇 |
1978年 | 206篇 |
1977年 | 148篇 |
1976年 | 141篇 |
1975年 | 145篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
Chu‐Lin Tsai MD MPH Justin A. Sobrino BS Carlos A. Camargo Jr MD DrPH 《Academic emergency medicine》2008,15(12):1275-1283
Objectives: Little is known about recent trends in U.S. emergency department (ED) visits for acute exacerbation of chronic obstructive pulmonary disease (AECOPD) or about ED management of AECOPD. This study aimed to describe the epidemiology of ED visits for AECOPD and to evaluate concordance with guideline‐recommended care. Methods: Data were obtained from National Hospital Ambulatory Medical Care Survey (NHAMCS). ED visits for AECOPD, during 1993 to 2005, were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD‐9‐CM) codes. Concordance with guideline recommendations was evaluated using process measures. Results: Over the 13‐year study period, there was an average annual 0.6 million ED visits for AECOPD, and the visit rates for AECOPD were consistently high (3.2 per 1,000 U.S. population; Ptrend = 0.13). The trends in the use of chest radiograph, pulse oximetry, or bronchodilator remained stable (all Ptrend > 0.5). By contrast, the use of systemic corticosteroids increased from 29% in 1993–1994 to 60% in 2005, antibiotics increased from 14% to 42%, and methylxanthines decreased from 15% to <1% (all Ptrend < 0.001). Multivariable analysis showed patients in the South (vs. the Northeast) were less likely to receive systemic corticosteroids (odds ratio [OR] = 0.6; 95% confidence interval [CI] = 0.4 to 0.9). Conclusions: The high burden of ED visits for AECOPD persisted. Overall concordance with guideline‐recommended care for AECOPD was moderate, and some emergency treatments had improved over time. 相似文献
112.
In today''s environment, providers are extremely time-constrained. Assembling relevant contextual data to make decisions on laboratory results can take a significant amount of time from the day. The Regenstrief Institute has created a system which leverages data within Indiana Health Information Exchange''s (IHIE''s) repository, the Indiana Network for Patient Care (INPC), to provide well-organized and contextual information on returning laboratory results to outpatient providers. The system described here uses data extracted from INPC to add historical test results, medication-dispensing events, visit information, and clinical reminders to traditional laboratory result reports. These “Enhanced Laboratory Reports” (ELRs) are seamlessly delivered to outpatient practices connected through IHIE via the DOCS4DOCS clinical messaging service. All practices, including those without electronic medical record systems, can receive ELRs. In this paper, the design and implementation issues in creating this system are discussed, and generally favorable preliminary results of attitudes by providers towards ELRs are reported. 相似文献
113.
114.
Susan W. Volk VMD PhD ; Antoneta Radu BS ; Liping Zhang MS ; Kenneth W. Liechty MD 《Wound repair and regeneration》2007,15(5):736-747
Chronic wounds create a formidable clinical problem resulting in considerable morbidity and healthcare expenditure. The etiology for wound healing impairment appears to be multifactorial; however, ischemia is a common factor in most types of chronic wounds. Ideal therapy for such wounds would be to correct deficiencies in growth factors and matrix components and provide cellular precursors required for timely wound closure. We hypothesized that stromal progenitor cell (SPC) therapy could correct the ischemic wound-healing defect through both direct and indirect mechanisms. To test this hypothesis, we used the ischemic rabbit ear model of chronic wound healing. We found that treatment of the wounds with SPCs was able to reverse the ischemic wound-healing impairment, with improved granulation tissue formation and reepithelialization compared with vehicle or bone marrow mononuclear cell controls. In vitro, SPCs were found to produce factors involved in angiogenesis and reepithelialization, and extracellular matrix components, providing evidence for both direct and indirect mechanisms for the observed correction of the healing impairment in these wounds. Treatment of ischemic wounds with SPCs can dramatically improve wound healing and provides a rationale for further studies focused on SPCs as a potential cellular therapy in impaired wound healing. 相似文献
115.
116.
Xiangyu Piao Changkai Sun Zhe Jin Jing Yu Xiaodan Chang Xin Tang Hongmei Liu Peiyang Zhou 《中国神经再生研究》2007,2(9):540-543
BACKGROUND: The cerebral ischemia and ischemia/reperfusion animal models are used to simulate the human cerebrovascular diseases is one of the popular topics of neurological science recently. To study the pathophysiology, pathogenesis, prophylaxis and treatment of ischemic cerebrovascular diseases and to establish the ideal animal model that is the most similar to the human cerebral ischemia, are the topics that the people generally cared about.
OBJECTIVE: To evaluate the effects of aerocyst-blocking bilateral ascending pharyngeal artery on the establishment of cerebral ischemia models by using digital subtraction angiography (DSA), magnetic resonance diffusion-weighted imaging (DWI) and magnetic resonance perfusion-weighted imaging (PWI).
DESIGN: Repetitive measure animal experiment.
SETTING: Zhongshan Hospital Affiliated to Dalian University.
MATERIALS: The experiment was carried out in the Animal Laboratory (Provincial Laboratory), Zhongshan Hospital of Dalian Univeristy from January to May 2006. A total of 14 domestic piglets, of 6 months old, weighing 12–15 kg, of either gender, were selected from Animal Experimental Center, Dalian University. Multistar T.O.P digital subtraction angiography machine was provided by Siemens Company, German.
METHODS: Aerocyst-blocking bilateral ascending pharyngeal artery was used to establish cerebral ischemia models. And then, Multistar T.O.P. DSA was used for imaging of cerebral vessels before blocking, during blocking and at 0.5 and 2 hours after ischemia perfusion. GE Signa 1.5 T supraconduction magnetic resonance imaging was used for DWI examination; in addition, PWI was used based on focal sites and areas. Otherwise, magnetic resonance imaging (MRI) was used to detect signal changes of T1WI and T2WI in ischemic areas.
MAIN OUTCOME MEASURES: Analytic results of DSA, DWI, PWI and MRI.
RESULTS: All 14 experimental piglets were involved in the final analysis. ① DSA: The blood flow of bilateral ascending pharyngeal arteries and its branch were blocked at blocking phase, which restored 0.5 and 2 hours after reperfusion. ② DWI and PWI: There were no observable abnormalities in PWI and DWI at pre-blocking. Abnormal increased signals were found on both DWI and PWI at during and post-blocking. There were reduction in ADC and rCBF and delay in rTTP at all time points except pre-blocking. ③ MRI: There were no abnormal signals observable at any time of pre- and post-blocking in T1WI and T2WI.
CONCLUSION: It is feasible to establish this kind of animal experimental models, and it can simulate the ischemic state; meanwhile, the existence and extent can be showed directly by DSA, DWI, and PWI. 相似文献
117.
Chin-Wan Luo Chung-Ji Liu Kuo-Ming Chang 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(4):e62-e65
Synovial cell sarcoma is a relatively rare tumor of mesenchymal origin. It is a high-grade neoplasm that microscopically shows a monophasic or biphasic cellular pattern and includes epithelial features as well as supporting tissue features. Surgical excision is the primary mode of treatment. Postoperative radiotherapy and chemotherapy also is seen to be helpful. Between 3% and 10% of cases originate in the head and neck. A review of relevant literature shows less than 10 cases of synovial cell sarcoma of the temporomandibular joint area reported in the English literature. We report an additional case of biphasic synovial cell sarcoma arising in the temporomandibular joint area, which caused ear pain, tinnitus, and hearing loss, and we further discuss the clinical features, histopathology, differential diagnosis, and treatment modality. 相似文献
118.
Eun Young Jung Hyung Joo Suh Wan Soo Hong Dong Geon Kim Yang Hee Hong In Sun Hong Un Jae Chang 《Nutrition Research》2009,29(7):457-461
Cooking processes that gelatinize granules or disrupt structure might increase the glucose and insulin responses because a disruption of the structure of starch by gelatinization increases its availability for digestion and absorption in the small intestine. We hypothesized that the uncooked form of rice, which has a relatively low degree of gelatinization even though in powder form, would result in lower metabolic glucose and insulin responses compared with cooked rice (CR). To assess the effects of the gelatinization of rice on metabolic response of glucose and insulin, we investigated the glucose and insulin responses to 3 rice meals of different gelatinization degree in female college students (n = 12): CR (76.9% gelatinized), uncooked rice powder (UP; 3.5% gelatinized), and uncooked freeze-dried rice powder (UFP; 5.4% gelatinized). Uncooked rice powders (UP and UFP) induced lower glucose and insulin responses compared with CR. The relatively low gelatinization degree of UPs resulted in low metabolic responses in terms of the glycemic index (CR: 72.4% vs UP: 49.7%, UFP: 59.8%) and insulin index (CR: 94.8% vs UP: 74.4%, UFP: 68.0%). In summary, UPs that were less gelatinized than CR induced low postprandial glucose and insulin responses. 相似文献
119.
120.
Nutritional supplementation, psychosocial stimulation, and growth of stunted children: the Jamaican study 总被引:3,自引:0,他引:3
S P Walker C A Powell S M Grantham-McGregor J H Himes S M Chang 《The American journal of clinical nutrition》1991,54(4):642-648
The benefits of nutritional supplementation, with or without psychosocial stimulation, on the growth of stunted children were evaluated. Children aged 9-24 mo with lengths less than -2 SD of the National Center for Health Statistics references (n = 129) were randomly assigned to four groups: control, nutritional supplementation, stimulation, and both interventions. A fifth group with lengths greater than -1 SD was also enrolled. Length, weight, head and arm circumferences, and triceps and subscapular skinfold thicknesses were measured on enrollment and 6 and 12 mo later. Multiple-regression analysis was used to determine the effects of the interventions in which age, sex, initial status, initial dietary intake, and several socioeconomic variables were controlled for. Stimulation had no effect on growth and there was no interaction between the interventions. After 12 mo supplemented children had significantly increased length, weight, and head circumference (all P less than 0.01). The effects of supplementation were not cumulative but occurred in the first 6 mo. 相似文献