全文获取类型
收费全文 | 89456篇 |
免费 | 5607篇 |
国内免费 | 1233篇 |
专业分类
耳鼻咽喉 | 870篇 |
儿科学 | 2163篇 |
妇产科学 | 1982篇 |
基础医学 | 10490篇 |
口腔科学 | 2722篇 |
临床医学 | 7470篇 |
内科学 | 22247篇 |
皮肤病学 | 1332篇 |
神经病学 | 8723篇 |
特种医学 | 3553篇 |
外国民族医学 | 3篇 |
外科学 | 12606篇 |
综合类 | 2210篇 |
现状与发展 | 1篇 |
一般理论 | 9篇 |
预防医学 | 4280篇 |
眼科学 | 1297篇 |
药学 | 6172篇 |
8篇 | |
中国医学 | 1031篇 |
肿瘤学 | 7127篇 |
出版年
2023年 | 762篇 |
2022年 | 1565篇 |
2021年 | 3023篇 |
2020年 | 1875篇 |
2019年 | 2299篇 |
2018年 | 2685篇 |
2017年 | 2148篇 |
2016年 | 2390篇 |
2015年 | 2750篇 |
2014年 | 3615篇 |
2013年 | 4437篇 |
2012年 | 6422篇 |
2011年 | 6339篇 |
2010年 | 3704篇 |
2009年 | 3392篇 |
2008年 | 5415篇 |
2007年 | 5419篇 |
2006年 | 5097篇 |
2005年 | 4719篇 |
2004年 | 4312篇 |
2003年 | 3845篇 |
2002年 | 3445篇 |
2001年 | 1758篇 |
2000年 | 1639篇 |
1999年 | 1587篇 |
1998年 | 824篇 |
1997年 | 649篇 |
1996年 | 603篇 |
1995年 | 510篇 |
1994年 | 466篇 |
1993年 | 408篇 |
1992年 | 850篇 |
1991年 | 711篇 |
1990年 | 668篇 |
1989年 | 648篇 |
1988年 | 580篇 |
1987年 | 527篇 |
1986年 | 491篇 |
1985年 | 421篇 |
1984年 | 371篇 |
1983年 | 289篇 |
1982年 | 209篇 |
1981年 | 154篇 |
1980年 | 148篇 |
1979年 | 270篇 |
1978年 | 175篇 |
1977年 | 145篇 |
1974年 | 154篇 |
1973年 | 160篇 |
1972年 | 145篇 |
排序方式: 共有10000条查询结果,搜索用时 734 毫秒
91.
慢性鼻窦炎鼻息肉合并支气管哮喘患者鼻窦内镜术后对支气管哮喘疗效的影响 总被引:13,自引:0,他引:13
目的观察鼻窦内镜术(endoscopic sinu ssurgery,ESS)对慢性鼻窦炎伴支气管哮喘患者哮喘发作的影响。方法对210例慢性鼻窦炎患者施行ESS术,其中伴有支气管哮喘病史者42例(20.0%)。210例患者均于术前、术后采用酶联免疫吸附测定法(ELISA)检测外周血单个核细胞(PBMC)培养上清液中的白细胞介素4(IL-4),干扰素γ(IFN-γ),可溶性白细胞介素2受体(sIL-2R)和可溶性IgE低亲和力受体(solube CD23,sCD23)的含量,并与20例正常对照组进行比较。通过主观和客观标准评定42例患者哮喘发作及对皮质类固醇的耐受状况,并对术后患者进行为期1年(10例)和3年(32例)的随访。结果鼻窦炎合并支气管哮喘患者术前PBMC培养上清液中IL-4,sIL-2R、sCD23含量较对照组显著升高,而IFN-γ含量较对照组显著减少。术后IL-4、sIL-2R、sCD23含量较对照组显著降低,而IFN-γ含量显著增高。术后哮喘改善水平由随访术后1年的45%提高到术后3年的70%。42例中32例(76%)哮喘发作次数明显减少,术前长期服用类固醇的2l例中,14例(67%)减少了对口服类固醇的使用。结论ESS对慢性鼻窦炎伴支气管哮喘患者的治疗有较满意的远期疗效。ESS能调节IL-4、IFN-γ sIL-2R、sCD23水平,降低哮喘的发作频率和对类固醇的依赖。 相似文献
92.
Ulrich Weber Christian WA Pfirrmann Rudolf O Kissling Juerg Hodler Marco Zanetti 《BMC musculoskeletal disorders》2007,8(1):20
Background
Ankylosing spondylitis is a chronic inflammatory rheumatic disorder which usually begins in early adulthood. The diagnosis is often delayed by many years. MR imaging has become the preferred imaging method for detection of early inflammation of the axial skeleton in ankylosing spondylitis. 相似文献93.
Max Heiland Philipp Pohlenz Marco Blessmann Christian R Habermann Lars Oesterhelweg Philipp C Begemann Christian Schmidgunst Felix A S Blake Klaus Püschel Rainer Schmelzle Dirk Schulze 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(6):814-820
OBJECTIVE: The aim of this study was to evaluate soft tissue image quality of a mobile cone-beam computed tomography (CBCT) scanner with an integrated flat-panel detector. STUDY DESIGN: Eight fresh human cadavers were used in this study. For evaluation of soft tissue visualization, CBCT data sets and corresponding computed tomography (CT) and magnetic resonance imaging (MRI) data sets were acquired. Evaluation was performed with the help of 10 defined cervical anatomical structures. RESULTS: The statistical analysis of the scoring results of 3 examiners revealed the CBCT images to be of inferior quality regarding the visualization of most of the predefined structures. Visualization without a significant difference was found regarding the demarcation of the vertebral bodies and the pyramidal cartilages, the arteriosclerosis of the carotids (compared with CT), and the laryngeal skeleton (compared with MRI). Regarding arteriosclerosis of the carotids compared with MRI, CBCT proved to be superior. CONCLUSIONS: The integration of a flat-panel detector improves soft tissue visualization using a mobile CBCT scanner. 相似文献
94.
Philipp Pohlenz Marco Blessmann Felix Blake Sven Heinrich Rainer Schmelzle Max Heiland 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,103(3):412-417
OBJECTIVES: Intraoperative cone-beam computerized tomography (CBCT) imaging has been introduced in oral and maxillofacial surgery. Using midfacial fractures as the pioneer model, this study describes the spectrum of further promising clinical indications for intraoperative CBCT and a clinical combination with intraoperative navigation. STUDY DESIGN: One hundred seventy-nine patients admitted for surgical treatment of the facial skeleton were included in the study. Intraoperatively, 3-dimensional images were generated with the mobile CBCT scanner Arcadis Orbic 3D, obtained from Siemens Medical Solutions, in a variety of indications. RESULTS: The acquisition of the data sets was uncomplicated, and image quality was sufficient to assess the postoperative result in all cases. In the example of a facial gunshot injury, a navigation system for intraoperative localization of the metal foreign bodies was used. 相似文献
95.
Stefano Di Domenico Giulio Bovio Maximiliano Gelli Ferruccio Ravazzoni Enzo Andorno Damiano Cottalasso Umberto Valente 《BMC surgery》2007,7(1):18
Background
Liver transplantation in presence of diffuse portal vein thrombosis is possible by using caval blood as portal inflow, through cavo-portal transposition. However, clinical results are heterogeneous and experimental studies are needed, but similar hemodynamic conditions are difficult to obtain, especially in small animals. Herein we describe a new simple model of cavo-portal transposition in rat. 相似文献96.
Marco Antonio Palma Rocio Ortiz Carlos Alvarez-Dardet Maria T. Ruiz 《Social science & medicine (1982)》2009
The possible effect of Government Consumption (a component of Gross Domestic Product (GDP)) on attainment of the hunger Millennium Development Goal (MDG1) was analyzed by evaluating the effect of macroeconomic, social, demographic and policy variables on average undernourished population. Eighty-four developing countries with data available on undernourished population were included in an ecological study. Regression models were applied to explore possible determinants of Undernourished between 1990 and 2004 and consequent achievement of the projected 2004 MDG1. In 2004, 1.4% of the overall undernourished population in the studied countries [70.16 million people] was in excess of the projected level required to meet MDG1. The multiple linear regression showed significant associations between Undernourished and poverty levels, the Gini Index, rural population and Government Consumption. The multiple logistic regression showed significant associations between achievement of projected 2004 MDG1 levels and Government Consumption and the Gini Index. The significant associations between Undernourished and Government Consumption suggest that the effects of GDP components on social conditions call for more thorough research and that policymakers such as governments and international financial institutions need to ensure that changes in distributive and redistributive policies do not negatively affect the possibility of achieving MDG1. 相似文献
97.
98.
Vincenzo Neri Antonio Ambrosi Giuseppe Di Lauro Tiziano Pio Valentino 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2006,10(1):66-69
OBJECTIVES: The aim of this study was to evaluate the safety and effectiveness of laparoscopic-assisted sigmoid colectomy for diverticulitis and to assess its postoperative advantages. METHODS: From 1999 to 2001, 5 patients were selectively operated on with a laparoscopic-assisted procedure for uncomplicated sigmoid diverticulitis. In the preceding period (September 1997 through December 1998), 4 patients underwent open procedures for the same pathology. The surgical indication with the same criteria was restrictive: at least 2 acute episodes had occurred that were treated with hospital admission and that were separated by an adequate period (2 months) of medical therapy. RESULTS: No conversions of laparoscopy to an open procedure were necessary. Age, sex, weight, morbidity, and mortality were similar between the 2 groups. Operative time was 180 minutes for laparoscopy and 120 minutes for laparotomy. Postoperative resumption of peristalsis was 24 hours versus 4 days, resumption of alimentation was on the second postoperative day versus the fifth postoperative day, and hospital stay was 7 days versus 12 days for laparoscopy and laparotomy, respectively. CONCLUSION: This study shows the feasibility and the advantages of elective laparoscopic-assisted colonic resection for uncomplicated sigmoid diverticulitis. The advantages of the laparoscopic approach are the lower need for analgesics and the more precocious ambulation, canalization, resumption of alimentation, and the shorter hospital stay. 相似文献
99.
Maria de Fátima Haueisen S. Diniz Valéria M. Azeredo Passos Marco Túlio C. Diniz 《Nutrition (Burbank, Los Angeles County, Calif.)》2010,26(10):925-931
ObjectiveThis review analyzes the literature concerning gut peptides and bariatric surgery, from 2005 to July 2009. In particular, we are interested in whether, and how, gastrointestinal peptide alterations following surgery interfere with appetite/satiety, and what role they might play in the resolution of comorbidities.Research methods and procedurePubMed/MEDLINE and ISI Web of Knowledge were used to search for human studies concerning gut peptides profiles after any bariatric operation technique.ResultsMost of the studies reviewed had longitudinal design, short follow-up, and low statistical power. The diversity of study results may be partially explained by methodological aspects. Glucagon-like peptide-1, gastric inhibitory peptide, and peptide YY alterations may contribute to the excellent results in glycemic control of diabetics. Results do vary depending on bariatric operation technique; this is particularly evident in the case of ghrelin, which has been much studied in recent years. Ghrelin suppression has been linked to increased satiety, alterations in energy homeostasis, and better glucose metabolism.ConclusionsThere is a lack of long-term data on gastrointestinal hormone profiles after bariatric surgery and the studies have many methodological pitfalls. We still need prospective, long-term, good methodological studies in this area. 相似文献
100.
F. Specchiulli R. Gabrieli D. Borsetti V. Di Carlo 《Journal of orthopaedics and traumatology》2007,8(3):123-127
We examined the clinical and radiographic results of 93 patients affected by knee arthritis or osteonecrosis subjected to
unilateral cementless mobile-bearing total knee arthroplasty with the LCS prothesis (Depuy/Johnson & Johnson). The mean follow-up
was 9.5 years (range, 7–12 years). Clinical evaluation was performed using the Knee Society rating system, while radiographic
evaluation was done according to the Knee Society roentgenographic system. At the latest follow-up, the mean knee score was
87 points: the functional score improved from 40 to 90. Radiolucent lines were small and not progressive. The implant survival
at 12 years was 88%. Six knees (7%) required revision for implant-related problems. We conclude that the mobile-bearing prosthesis
is a successful device even at long-term follow-up. 相似文献