全文获取类型
收费全文 | 14011篇 |
免费 | 779篇 |
国内免费 | 58篇 |
专业分类
耳鼻咽喉 | 91篇 |
儿科学 | 591篇 |
妇产科学 | 306篇 |
基础医学 | 2090篇 |
口腔科学 | 215篇 |
临床医学 | 1549篇 |
内科学 | 3167篇 |
皮肤病学 | 255篇 |
神经病学 | 1335篇 |
特种医学 | 388篇 |
外科学 | 1280篇 |
综合类 | 84篇 |
一般理论 | 9篇 |
预防医学 | 1122篇 |
眼科学 | 221篇 |
药学 | 957篇 |
中国医学 | 56篇 |
肿瘤学 | 1132篇 |
出版年
2023年 | 93篇 |
2022年 | 217篇 |
2021年 | 386篇 |
2020年 | 236篇 |
2019年 | 329篇 |
2018年 | 388篇 |
2017年 | 267篇 |
2016年 | 309篇 |
2015年 | 405篇 |
2014年 | 517篇 |
2013年 | 740篇 |
2012年 | 1057篇 |
2011年 | 1119篇 |
2010年 | 590篇 |
2009年 | 528篇 |
2008年 | 885篇 |
2007年 | 948篇 |
2006年 | 857篇 |
2005年 | 827篇 |
2004年 | 751篇 |
2003年 | 728篇 |
2002年 | 672篇 |
2001年 | 160篇 |
2000年 | 131篇 |
1999年 | 158篇 |
1998年 | 143篇 |
1997年 | 124篇 |
1996年 | 84篇 |
1995年 | 85篇 |
1994年 | 69篇 |
1993年 | 52篇 |
1992年 | 67篇 |
1991年 | 72篇 |
1990年 | 50篇 |
1989年 | 48篇 |
1988年 | 48篇 |
1987年 | 50篇 |
1986年 | 63篇 |
1985年 | 52篇 |
1984年 | 41篇 |
1983年 | 46篇 |
1982年 | 43篇 |
1981年 | 48篇 |
1980年 | 40篇 |
1979年 | 41篇 |
1978年 | 34篇 |
1977年 | 21篇 |
1975年 | 21篇 |
1974年 | 19篇 |
1970年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
201.
Elisa Postrach Rosa Aspalter Ulf Elbelt Michael Koller Rita Longin J?rg-Dieter Schulzke Luzia Valentini 《Journal of medical Internet research》2013,15(10)
Background
The Internet is widely available and commonly used for health information; therefore, Web-based weight loss programs could provide support to large parts of the population in self-guided weight loss. Previous studies showed that Web-based weight loss interventions can be effective, depending on the quality of the program. The most effective program tools are visual progress charts or tools for the self-monitoring of weight, diet, and exercises. KiloCoach, a commercial program currently available in German-speaking countries, incorporates these features. A previous investigation showed that the program effectively supports users in losing weight.Objective
We investigated weight loss dynamics stratified by weight loss success after 6-month use of KiloCoach. Furthermore, we analyzed possible associations between intensity of program use and weight loss. The results are intended for tailoring user recommendations for weight-loss Internet platforms.Methods
Datasets of KiloCoach users (January 1, 2008 to December 31, 2011) who actively used the platform for 6 months or more were assigned to this retrospective analysis. Users (N=479) were 42.2% men, mean age of 44.0 years (SD 11.7), with a mean body mass index (BMI) of 31.7 kg/m2 (SD 3.2). Based on the weight loss achieved after 6 months, 3 success groups were generated. The unsuccessful group lost <5%, the moderate success group lost 5%-9.9%, and the high success group lost ≥10% of their baseline body weight. At baseline, the unsuccessful (n=261, 54.5%), moderate success (n=133, 27.8%), and high success (n=85, 17.8%) groups were similar in age, weight, BMI, and gender distribution.Results
After 6 months, the unsuccessful group lost 1.2% (SD 2.4), the moderate success group lost 7.4% (SD 1.5), and the high success group lost 14.2% (SD 3.8) of their initial weight (P<.001). Multivariate regression showed that early weight loss (weeks 3-4), the total number of dietary protocols, and the total number of weight entries were independent predictors for 6-month weight reduction (all P<.001) explaining 52% of the variance in weight reduction. Sensitivity analysis by baseline carried forward method confirmed all independent predictors of 6-month weight loss and reduced the model fit by only 11%. The high success group lost weight faster and maintained weight loss more efficiently than the other groups (P<.001). Early weight loss was associated with weight maintenance after 1 year and 2 years (both P<.001). Weight dynamics did not differ between men and women over 6 months when adjusted for baseline and usage parameters (P=.91). The percentage of male long-term users was unusually high (42.2%).Conclusions
Our results suggest that early weight loss and close program adherence (ie, 5 dietary protocols per week and weekly entering of current weight), especially in the early phase of program usage, can improve weight loss outcome. 相似文献202.
Fernando Augusto Vasilceac Rita de Cássia Marqueti Ivo Vieira de Sousa Neto Dahan da Cunha Nascimento Mariana Carvalho de Souza João Luiz Quaglioti Durigan Stela Márcia Mattiello 《Revista brasileira de fisioterapia (S?o Carlos (S?o Paulo, Brazil))》2021,25(2):147-155
BackgroundOsteoarthritis (OA) is a degenerative disease that induces peri-articular tissue degradation. OA induces an imbalance between synthesis and degradation of the extracellular matrix components in favor of catabolic events, promoting pathological remodeling and involving degradative enzymes, such as matrix metalloproteinases (MMPs).ObjectiveThis study aimed to investigate the effects of 8-weeks resistance training (RT) on MMP-2 activity in the quadriceps tendon and patellar tendon in an OA model.MethodsTwenty-four Wistar rats were randomly divided into six groups: Control, Exercise, Sham, Sham with Exercise, OA, and OA with Exercise (OAE). The OA model was performed by anterior cruciate ligament transection surgery on the left knee. The 8-week RT consisted of climbing a 1.1-m vertical ladder three times per week with progressive weights secured to the animals’ tails. MMP-2 activity was analyzed by zymography.ResultsThe OAE group displayed lower pro, intermediate, and active MMP-2 activity in the quadriceps tendon compared with the OA group (p < 0.05). For the patellar tendon, there was no significant difference between the OAE group compared with the other groups (p > 0.05) for pro, intermediate, and active MMP-2 activity. Moreover, MMP-2 activity differed between tissues, the OA and OAE groups presented lower pro, intermediate, and active MMP-2 activity in the quadriceps tendon compared to the patellar tendon.ConclusionRT induced down-regulated MMP-2 activity in the quadriceps tendon. RT is a potential therapeutic approach to minimize the deleterious effects of extracellular matrix degeneration. 相似文献
203.
Isabel Fragata Teresa Morais Rita Silva Ana Paiva Nunes Petra Loureiro Jos Diogo Martins Jaime Pamplona Rui Carvalho Mariana Baptista Joo Reis 《Interventional neuroradiology》2021,27(1):16
IntroductionMechanical thrombectomy is standard treatment for large vessel occlusion (LVO) in adults. There are no randomized controlled trials for the pediatric population. We report our single-center experience with thrombectomy of LVO in a series of pediatric patients, and perform a review of the literature.MethodsRetrospective review of consecutive pediatric thrombectomy cases between 2011 and 2018. Demographic variables, imaging data, technical aspects and clinical outcome were recorded.ResultsIn a period of 7 years, 7 children were treated for LVO at our center. Median age was 13 (2–17), and median Ped-NIHSS was 15 (3–24), and the median ASPECTS was 8 (2–10). Five patients had cardiac disease, and 2 of them were under external cardiac assistance. Median time from onset of symptoms to beginning of treatment was 7h06m (2h58m–21h38m). Five patients had middle cerebral artery occlusions. Thrombectomy was performed using a stentriever in 3 patients, aspiration in 3 patients, and combined technique in 1 patient. Six patients had good recanalization (TICI 2 b/3). There were no immediate periprocedural complications. At 3 months, 4 patients (57%) were independent (mRS score <3). Two patients died, one after haemorrhagic transformation of an extensive MCA infarct, and one due to extensive brainstem ischemia in the setting of varicella vasculitis.DiscussionSelected pediatric patients with LVO may be treated with mechanical thrombectomy safely. In patients under external cardiac assistance and under anticoagulation, thrombectomy is the only alternative for treatment of LVO. A multidisciplinary approach in specialized pediatric stroke centers with trained neurointerventionalists are essential for good results. 相似文献
204.
Correction for ‘Thermodynamically stable vesicle formation of biodegradable double mPEG-tailed amphiphiles with sulfonate head group’ by Rita Ghosh et al., RSC Adv., 2020, 10, 32522–32531, DOI: 10.1039/D0RA05613HThe authors regret that an incorrect version of Fig. 5 was included in the original article. The correct version of Fig. 5 is presented below.Open in a separate windowFig. 1Upper panel: Size distribution histograms of aggregates in 2.0 mM solutions (pH 7) of (a) (mPEG4)2SO3Na, and (b) (mPEG23)2SO3Na at 25 °C; lower panel: unstained HRTEM images of 2 mM (c) (mPEG4)2SO3Na and (d) (mPEG23)2SO3Na solutions in phosphate buffer (pH 7.0).The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers. 相似文献
205.
Glen R. Gallagher Michael A. Brehm Robert W. Finberg Bruce A. Barton Leonard D. Shultz Dale L. Greiner Rita Bortell Jennifer P. Wang 《Diabetes》2015,64(4):1358-1369
Type 1 diabetes (T1D) is characterized by the destruction of the insulin-producing β-cells of pancreatic islets. Genetic and environmental factors both contribute to T1D development. Viral infection with enteroviruses is a suspected trigger for T1D, but a causal role remains unproven and controversial. Studies in animals are problematic because of species-specific differences in host cell susceptibility and immune responses to candidate viral pathogens such as coxsackievirus B (CVB). In order to resolve the controversial role of viruses in human T1D, we developed a viral infection model in immunodeficient mice bearing human islet grafts. Hyperglycemia was induced in mice by specific ablation of native β-cells. Human islets, which are naturally susceptible to CVB infection, were transplanted to restore normoglycemia. Transplanted mice were infected with CVB4 and monitored for hyperglycemia. Forty-seven percent of CVB4-infected mice developed hyperglycemia. Human islet grafts from infected mice contained viral RNA, expressed viral protein, and had reduced insulin levels compared with grafts from uninfected mice. Human-specific gene expression profiles in grafts from infected mice revealed the induction of multiple interferon-stimulated genes. Thus, human islets can become severely dysfunctional with diminished insulin production after CVB infection of β-cells, resulting in diabetes. 相似文献
206.
207.
208.
ER Stress During the Pubertal Growth Spurt Results in Impaired Long‐Bone Growth in Chondrocyte‐Specific ERp57 Knockout Mice 下载免费PDF全文
Andrea Linz Yvonne Knieper Tobias Gronau Uwe Hansen Attila Aszodi Natalio Garbi Günter J Hämmerling Thomas Pap Peter Bruckner Rita Dreier 《Journal of bone and mineral research》2015,30(8):1481-1493
Long‐bone growth by endochondral ossification is cooperatively accomplished by chondrocyte proliferation, hypertrophic differentiation, and appropriate secretion of collagens, glycoproteins, and proteoglycans into the extracellular matrix (ECM). Before folding and entering the secretory pathway, ECM macromolecules in general are subject to extensive posttranslational modification, orchestrated by chaperone complexes in the endoplasmic reticulum (ER). ERp57 is a member of the protein disulfide isomerase (PDI) family and facilitates correct folding of newly synthesized glycoproteins by rearrangement of native disulfide bonds. Here, we show that ERp57‐dependent PDI activity is essential for postnatal skeletal growth, especially during the pubertal growth spurt characterized by intensive matrix deposition. Loss of ERp57 in growth plates of cartilage‐specific ERp57 knockout mice (ERp57 KO) results in ER stress, unfolded protein response (UPR), reduced proliferation, and accelerated apoptotic cell death of chondrocytes. Together this results in a delay of long‐bone growth with the following characteristics: (1) enlarged growth plates; (2) expanded hypertrophic zones; (3) retarded osteoclast recruitment; (4) delayed remodeling of the proteoglycan‐rich matrix; and (5) reduced numbers of bone trabeculae. All the growth plate and bone abnormalities, however, become attenuated after the pubertal growth spurt, when protein synthesis is decelerated and, hence, ERp57 function is less essential. © 2015 American Society for Bone and Mineral Research. 相似文献
209.
210.
Gabriele?Donati Maria?Ilaria?Moretti Olga?Baraldi Alessandra?Spazzoli Irene?Capelli Giorgia?Comai Antonio?Marchetti Maria?Sarma Rita?Mancini Gaetano?La MannaEmail author 《BMC nephrology》2016,17(1):193