全文获取类型
收费全文 | 142244篇 |
免费 | 10740篇 |
国内免费 | 252篇 |
专业分类
耳鼻咽喉 | 1243篇 |
儿科学 | 3974篇 |
妇产科学 | 3089篇 |
基础医学 | 22129篇 |
口腔科学 | 3614篇 |
临床医学 | 12565篇 |
内科学 | 28792篇 |
皮肤病学 | 2484篇 |
神经病学 | 13905篇 |
特种医学 | 5688篇 |
外国民族医学 | 9篇 |
外科学 | 17368篇 |
综合类 | 671篇 |
现状与发展 | 2篇 |
一般理论 | 126篇 |
预防医学 | 16204篇 |
眼科学 | 2214篇 |
药学 | 8747篇 |
中国医学 | 291篇 |
肿瘤学 | 10121篇 |
出版年
2023年 | 712篇 |
2022年 | 877篇 |
2021年 | 2601篇 |
2020年 | 1856篇 |
2019年 | 2743篇 |
2018年 | 3271篇 |
2017年 | 2738篇 |
2016年 | 2922篇 |
2015年 | 3251篇 |
2014年 | 4420篇 |
2013年 | 5757篇 |
2012年 | 8920篇 |
2011年 | 8901篇 |
2010年 | 4606篇 |
2009年 | 4764篇 |
2008年 | 7734篇 |
2007年 | 7976篇 |
2006年 | 7521篇 |
2005年 | 7225篇 |
2004年 | 6188篇 |
2003年 | 5764篇 |
2002年 | 5277篇 |
2001年 | 4549篇 |
2000年 | 4441篇 |
1999年 | 3999篇 |
1998年 | 1715篇 |
1997年 | 1427篇 |
1996年 | 1453篇 |
1995年 | 1192篇 |
1994年 | 1119篇 |
1993年 | 1012篇 |
1992年 | 2715篇 |
1991年 | 2432篇 |
1990年 | 2311篇 |
1989年 | 2156篇 |
1988年 | 1979篇 |
1987年 | 1734篇 |
1986年 | 1650篇 |
1985年 | 1569篇 |
1984年 | 1123篇 |
1983年 | 973篇 |
1982年 | 544篇 |
1981年 | 474篇 |
1980年 | 399篇 |
1979年 | 869篇 |
1978年 | 529篇 |
1977年 | 435篇 |
1974年 | 417篇 |
1973年 | 411篇 |
1972年 | 367篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
Widely Metastatic Squamous Cell Carcinoma Originating from Malignant Transformation of Hypertrophic Lichen Planus in a 24‐Year‐Old Woman: Case Report and Review of the Literature 下载免费PDF全文
Lana X. Tong B.A. Matthew J. Weinstock M.D. Reed Drews M.D. Caroline C. Kim M.D. 《Pediatric dermatology》2015,32(3):e98-e101
Hypertrophic lichen planus (HLP) is a T‐cell‐mediated process typically presenting with hypertrophic or verrucous plaques on the lower limbs. We report the case of a 24‐year‐old woman with a history of HLP since age 3 years presenting with rapid malignant transformation of one lesion into a large squamous cell carcinoma (SCC). Subsequent examination revealed progressive, widespread metastatic involvement, and the patient ultimately died from her disease. SCC associated with HLP is rare, with a review of the literature revealing fewer than 50 cases. This case highlights the need to be aware of suspicious changes in HLP and to educate patients as to when to be reevaluated. 相似文献
22.
23.
Ragnhild B. Wijma Marloes Emous Merel van den Broek Anke Laskewitz Anneke C. Muller Kobold André P. van Beek 《Surgery for obesity and related diseases》2019,15(1):73-81
Background
Early dumping is a poorly defined and incompletely understood complication after Roux-en-Y gastric (RYGB).Objective
We performed a mixed-meal tolerance test in patients after RYGB to address the prevalence of early dumping and to gain further insight into its pathophysiology.Setting
The study was conducted in a regional hospital in the northern part of the Netherlands.Methods
From a random sample of patients who underwent primary RYGB between 2008 and 2011, 46 patients completed the mixed-meal tolerance test. The dumping severity score for early dumping was assessed every 30 minutes. A sum score at 30 or 60 minutes of ≥5 and an incremental score of ≥3 points were defined as indicating a high suspicion of early dumping. Blood samples were collected at baseline, every 10 minutes during the first half hour, and at 60 minutes after the start.Results
The prevalence of a high suspicion of early dumping was 26%. No differences were seen for absolute hematocrit value, inactive glucagon-like peptide-1, and vasoactive intestinal peptide between patients with or without early dumping. Patients at high suspicion of early dumping had higher levels of active glucagon-like peptide-1 and peptide YY.Conclusion
The prevalence of complaints at high suspicion of early dumping in a random population of patients after RYGB is 26% in response to a mixed-meal tolerance test. Postprandial increases in both glucagon-like peptide-1 and peptide YY are associated with symptoms of early dumping, suggesting gut L-cell overactivity in this syndrome. 相似文献24.
Background
Many patients undergoing below knee amputations (BKA) return for subsequent unplanned operations, hospital readmission, or postoperative complications. This unplanned medical management negatively impacts both patient outcomes and our healthcare system. This study primarily investigates the risk factors for unplanned reoperation following BKA.Methods
Below knee amputations from the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database from the years 2012–2014 were identified by CPT code 27880 for amputation through the tibia and fibula. Our query identified 4631 BKA cases, including 30 day complications. Multivariate logistic regression modeling was performed on several patient demographic and disease factors to assess for independent predictors of unplanned reoperation. Secondary outcomes of unplanned and related readmissions (related to the procedure), major complications, minor complications, and mortality were also included in the analysis.Results
Of 4631 BKAs identified, 9.63% (446/4631) underwent unplanned reoperations and 8.75% (405/4631) had unplanned and related readmissions. Major complications were experienced by 12.8% (593/4631) and minor complications by 8.7% (401/4631). Thirty day mortality rate was 5.14% (238/4631). The most common procedures for unplanned operations were thigh amputations (128/446, 28.7%), debridement/secondary closure (114/446, 25.6%), and revision leg amputations (46/446, 10.32%). Factors associated with an increased risk of unplanned reoperation included patients transferred from another facility (Adjusted Odds Ratio [AOR]?=?1.28; p?=?.04), recent smokers (AOR?=?1.34; p?=?.02), bleeding disorder (AOR?=?1.30; p?=?.02), and preoperative ventilator use (AOR?=?2.38; p?=?.01).Conclusion
Patients that were ongoing/recent smokers, had diagnosed bleeding disorders, required preoperative ventilator use, or were transferred in from another facility were associated with the highest risks of reoperation following BKA. This patient population experiences high rates of reoperation, readmission, complication, and mortality. 相似文献25.
Anastasiia Panfilova Sarah E. Shelton Cristina Caresio Ruud J.G. van Sloun Filippo Molinari Hessel Wijkstra Paul A. Dayton Massimo Mischi 《Ultrasound in medicine & biology》2019,45(2):539-548
Dynamic contrast-enhanced ultrasound (DCE-US) has been proposed as a powerful tool for cancer diagnosis by estimation of perfusion and dispersion parameters reflecting angiogenic vascular changes. This work was aimed at identifying which vascular features are reflected by the estimated perfusion and dispersion parameters through comparison with acoustic angiography (AA). AA is a high-resolution technique that allows quantification of vascular morphology. Three-dimensional AA and 2-D DCE-US bolus acquisitions were used to monitor the growth of fibrosarcoma tumors in nine rats. AA-derived vascular properties were analyzed along with DCE-US perfusion and dispersion to investigate the differences between tumor and control and their evolution in time. AA-derived microvascular density and DCE-US perfusion exhibited good agreement, confirmed by their spatial distributions. No vascular feature was correlated with dispersion. Yet, dispersion provided better cancer classification than perfusion. We therefore hypothesize that dispersion characterizes vessels that are smaller than those visible with AA. 相似文献
26.
Caroline Williamsson Jenny Rystedt Bodil Andersson 《HPB : the official journal of the International Hepato Pancreato Biliary Association》2021,23(6):847-853
BackgroundLittle is known of possible gender differences in treatment of periampullary tumours and outcome after pancreatoduodenectomy (PD), and the aim of this study was therefore to investigate any variances from national multicentre perspective.MethodsData from the Swedish National Registry for Pancreatic and Periampullary Cancer for all patients diagnosed with a periampullary tumour from 2012 throughout 2017 was collected. The material was analysed in two groups, men and women, for palliative treatment and curative intended resection.ResultsA total of 5677 patients were included, 2906 (51%) men and 2771 (49%) women. Women were older than men, 72 (65–78) years vs. 70 (64–76), p < 0.001. A lesser proportion of women were planned for resection (1131 (41%) vs. 1288 (44%), p = 0.008), but after adjusting for age and tumour location no difference was seen. Postoperative morbidity was equal, but women had significantly better long-term survival than men. The survival was equal for palliative men and women.ConclusionNo gender bias could be established when analysing treatment for periampullary tumours in Sweden, even though less women were offered surgery. Data suggest that even though women were older they tolerate surgery well and hence offering PD at a higher age for women could be suggested. 相似文献
27.
Erik de Bakker Mirthe A. M. van der Putten Martijn W. Heymans Sander W. Spiekstra Taco Waaijman Liselotte Butzelaar Vera L. Negenborn Vivian K. Beekman Erman O. Akpinar Thomas Rustemeyer Frank B. Niessen Susan Gibbs 《Experimental dermatology》2021,30(1):169-178
Unpredictable hypertrophic scarring (HS) occurs after approximately 35% of all surgical procedures and causes significant physical and psychological complaints. Parallel to the need to understanding the mechanisms underlying HS formation, a prognostic tool is needed. The objective was to determine whether (systemic) immunological differences exist between patients who develop HS and those who develop normotrophic scars (NS) and to assess whether those differences can be used to identify patients prone to developing HS. A prospective cohort study with NS and HS groups in which (a) cytokine release by peripheral blood mononuclear cells (PBMC) and (b) the irritation threshold (IT) after an irritant (sodium lauryl sulphate) patch test was evaluated. Univariate regression analysis of PBMC cytokine secretion showed that low MCP‐1, IL‐8, IL‐18 and IL‐23 levels have a strong correlation with HS (P < .010‐0.004; AUC = 0.790‐0.883). Notably, combinations of two or three cytokines (TNF‐a, MCP‐1 and IL‐23; AUC: 0.942, Nagelkerke R2: 0.727) showed an improved AUC indicating a better correlation with HS than single cytokine analysis. These combination models produce good prognostic results over a broad probability range (sensitivity: 93.8%, specificity 86.7%, accuracy 90,25% between probability 0.3 and 0.7). Furthermore, the HS group had a lower IT than the NS group and an accuracy of 68%. In conclusion, very fundamental immunological differences exist between individuals who develop HS and those who do not, whereas the cytokine assay forms the basis of a predictive prognostic test for HS formation, the less invasive, easily performed irritant skin patch test is more accessible for daily practice. 相似文献
28.
29.
30.
Marie V. Plaisime PhD MPH Marie Jipguep-Akhtar PhD Joseph J. Locascio PhD Harolyn M. E. Belcher MD MHS Rachel R. Hardeman PhD MPH Katherine Picho-Kiroga PhD Sylvia P. Perry PhD Sean M. Phelan PhD MPH Michelle van Ryn PhD LMFT MPH John F. Dovidio PhD 《Health services research》2023,58(Z2):229-237