全文获取类型
收费全文 | 183162篇 |
免费 | 8170篇 |
国内免费 | 388篇 |
专业分类
耳鼻咽喉 | 2340篇 |
儿科学 | 5305篇 |
妇产科学 | 4333篇 |
基础医学 | 26516篇 |
口腔科学 | 5859篇 |
临床医学 | 11486篇 |
内科学 | 39929篇 |
皮肤病学 | 4834篇 |
神经病学 | 15288篇 |
特种医学 | 4657篇 |
外国民族医学 | 1篇 |
外科学 | 20826篇 |
综合类 | 927篇 |
现状与发展 | 1篇 |
一般理论 | 44篇 |
预防医学 | 21722篇 |
眼科学 | 4649篇 |
药学 | 14297篇 |
中国医学 | 728篇 |
肿瘤学 | 7978篇 |
出版年
2023年 | 1063篇 |
2022年 | 957篇 |
2021年 | 3146篇 |
2020年 | 1870篇 |
2019年 | 3589篇 |
2018年 | 5696篇 |
2017年 | 3679篇 |
2016年 | 3663篇 |
2015年 | 4054篇 |
2014年 | 4573篇 |
2013年 | 6832篇 |
2012年 | 11748篇 |
2011年 | 12249篇 |
2010年 | 6063篇 |
2009年 | 4596篇 |
2008年 | 9939篇 |
2007年 | 10617篇 |
2006年 | 10051篇 |
2005年 | 9717篇 |
2004年 | 8949篇 |
2003年 | 8313篇 |
2002年 | 7878篇 |
2001年 | 5047篇 |
2000年 | 5554篇 |
1999年 | 4282篇 |
1998年 | 841篇 |
1992年 | 2282篇 |
1991年 | 2045篇 |
1990年 | 2039篇 |
1989年 | 1723篇 |
1988年 | 1655篇 |
1987年 | 1549篇 |
1986年 | 1589篇 |
1985年 | 1489篇 |
1984年 | 1064篇 |
1983年 | 910篇 |
1979年 | 1221篇 |
1978年 | 821篇 |
1977年 | 796篇 |
1976年 | 749篇 |
1975年 | 890篇 |
1974年 | 1131篇 |
1973年 | 1174篇 |
1972年 | 1125篇 |
1971年 | 1087篇 |
1970年 | 1009篇 |
1969年 | 1090篇 |
1968年 | 1122篇 |
1967年 | 991篇 |
1966年 | 894篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
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
34.
35.
Melatonin reduces oxidative stress and improves vascular function in pulmonary hypertensive newborn sheep 下载免费PDF全文
Flavio Torres Alejandro González‐Candia Camilo Montt Germán Ebensperger Magdalena Chubretovic María Serón‐Ferré Roberto V. Reyes Aníbal J. Llanos Emilio A. Herrera 《Journal of pineal research》2015,58(3):362-373
Pulmonary hypertension of the newborn (PHN) constitutes a critical condition with severe cardiovascular and neurological consequences. One of its main causes is hypoxia during gestation, and thus, it is a public health concern in populations living above 2500 m. Although some mechanisms are recognized, the pathophysiological facts that lead to PHN are not fully understood, which explains the lack of an effective treatment. Oxidative stress is one of the proposed mechanisms inducing pulmonary vascular dysfunction and PHN. Therefore, we assessed whether melatonin, a potent antioxidant, improves pulmonary vascular function. Twelve newborn sheep were gestated, born, and raised at 3600 meters. At 3 days old, lambs were catheterized and daily cardiovascular measurements were recorded. Lambs were divided into two groups, one received daily vehicle as control and another received daily melatonin (1 mg/kg/d), for 8 days. At 11 days old, lung tissue and small pulmonary arteries (SPA) were collected. Melatonin decreased pulmonary pressure and resistance for the first 3 days of treatment. Further, melatonin significantly improved the vasodilator function of SPA, enhancing the endothelial‐ and muscular‐dependent pathways. This was associated with an enhanced nitric oxide‐dependent and nitric oxide independent vasodilator components and with increased nitric oxide bioavailability in lung tissue. Further, melatonin reduced the pulmonary oxidative stress markers and increased enzymatic and nonenzymatic antioxidant capacity. Finally, these effects were associated with an increase of lumen diameter and a mild decrease in the wall of the pulmonary arteries. These outcomes support the use of melatonin as an adjuvant in the treatment for PHN. 相似文献
36.
37.
38.
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39.
José Antonio Pereira Miguel Pera Manuel López-Cano Marta Pascual Sandra Alonso Silvia Salvans Marta Jiménez-Toscano Alba González-Martín Luis Grande-Posa 《Cirugía espa?ola》2019,97(1):20-26
Objectives
To determine the incidence of incisional hernia (IH) in the extraction incision (EI) in colorectal resection for cancer. To analyze whether the location of the incision has any relationship with the incidence of hernias and whether mesh could be useful for prevention in high-risk patients.Methods
Retrospective review of the colon and rectal surgery database from January 2015 to December 2016. Data were classified into 2 groups, transverse (TI) and midline incision (MI), and the latter was divided into 2 subgroups (mesh [MIM] and suture [MIS]). Patients were classified using the HERNIAscore. Hernias were diagnosed by clinical and/or CT examination.Results
A total of 182 out of 210 surgical patients were included. After a median follow-up of 13.0 months, 39 IH (21.9%) were detected, 23 of which (13.4%) were in the EI; their frequency was lower in the TI group (3.4%) and in the MIM group (5.9%) than in the MIS group (29.5%; p = 0.007). The probability of developing IH in the MIS group showed an OR = 11.7 (95%CI: 3.3-42.0) compared to the TI group and 4.3 (IC 95%: 1.1-16.3) versus the MIM group.Conclusions
The location of the incision is relevant to avoid incisional hernias. Transverse incisions should be used as the first option. When a midline incision is needed, a prophylactic mesh could be considered in high risk patients because it is safe and associated with low morbidity. 相似文献40.