全文获取类型
收费全文 | 4821篇 |
免费 | 226篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 53篇 |
妇产科学 | 65篇 |
基础医学 | 516篇 |
口腔科学 | 84篇 |
临床医学 | 589篇 |
内科学 | 1457篇 |
皮肤病学 | 53篇 |
神经病学 | 577篇 |
特种医学 | 90篇 |
外科学 | 421篇 |
综合类 | 13篇 |
预防医学 | 460篇 |
眼科学 | 33篇 |
药学 | 358篇 |
中国医学 | 3篇 |
肿瘤学 | 279篇 |
出版年
2024年 | 5篇 |
2023年 | 25篇 |
2022年 | 85篇 |
2021年 | 179篇 |
2020年 | 92篇 |
2019年 | 157篇 |
2018年 | 198篇 |
2017年 | 117篇 |
2016年 | 118篇 |
2015年 | 126篇 |
2014年 | 217篇 |
2013年 | 261篇 |
2012年 | 413篇 |
2011年 | 429篇 |
2010年 | 262篇 |
2009年 | 211篇 |
2008年 | 322篇 |
2007年 | 301篇 |
2006年 | 311篇 |
2005年 | 284篇 |
2004年 | 258篇 |
2003年 | 225篇 |
2002年 | 201篇 |
2001年 | 24篇 |
2000年 | 15篇 |
1999年 | 28篇 |
1998年 | 38篇 |
1997年 | 32篇 |
1996年 | 22篇 |
1995年 | 27篇 |
1994年 | 18篇 |
1993年 | 7篇 |
1992年 | 4篇 |
1991年 | 8篇 |
1990年 | 8篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1971年 | 1篇 |
1964年 | 1篇 |
1962年 | 2篇 |
1961年 | 1篇 |
1960年 | 3篇 |
1933年 | 1篇 |
1929年 | 1篇 |
排序方式: 共有5065条查询结果,搜索用时 15 毫秒
31.
Mercè Cladellas Jordi Bruguera Josep Comín Joan Vila Elisabeth de Jaime Julio Martí Miquel Gomez 《European heart journal》2006,27(9):1093-1099
AIMS: To assess the level of pre-operative haemoglobin (HB) as a risk marker for morbidity and mortality in the early post-operative period of patients who underwent elective valve replacement. METHODS AND RESULTS: Between January 1998 and March 2004, clinical and outcomes data were collected for the 201 patients who had elective valve replacement. For each gender, the criterion to choose the best cut-off point was that which achieved the maximum likelihood after several General Additive Model models performed in a Bootstrap procedure. The best cut-off point obtained for pre-operative HB was 12 g/dL. Overall peri-operative mortality (deaths occurring during hospital period or within 30 days) was 9.5%. After adjusting well-known independent pre-operative risk factors for operative mortality, pre-operative HB <12 g/dL was identified as an independent predictor for in-hospital mortality (OR, 3.23; 95% CI, 1.09-9.55; P = 0.03). Also adjusting for EuroScore, pre-operative HB remained significant (OR, 3.64; 95% CI, 1.32-10.06; P = 0.01). The same model was applied to post-operative morbidity, and pre-operative HB <12 g/dL was identified as an independent predictor with and without EuroScore (OR, 4.67; 95% CI, 2.03-10.71; P < 0.001), (OR, 5.18; 95% CI, 2.18-12.3; P < 0.001), respectively. CONCLUSION: In patients undergoing elective valve replacement pre-operative HB <12 g/dL is a risk marker of in-hospital mortality and serious adverse outcomes. 相似文献
32.
33.
Jaume Francisco-Pascual Eduard Rodenas Yassin Belahnech Nuria Rivas-Gándara Jordi Pérez-Rodon Alba Santos-Ortega Begoña Benito Ivo Roca-Luque Yolima Cossio-Gil Vicens Serra Garcia Sandra Llerena-Butron Julian Rodríguez-García Angel Moya-Mitjans David García-Dorado Ignacio Ferreira-González 《The Canadian journal of cardiology》2021,37(2):284-291
BackgroundSevere aortic stenosis (AoS) is considered a primary cause of syncope. However, other mechanisms may be present in these patients and accurate diagnosis can have important clinical implications. The aim of this study is to assess the different etiologies of syncope in patients with severe AoS and the impact on prognosis of attaining a certain or highly probable diagnosis for the syncope.MethodsOut of a cohort of 331 patients with AoS and syncope, 61 had severe AoS and were included in the study. Main cause of syncope and adverse cardiac events were assessed.ResultsIn 40 patients (65.6%), we reached a certain or highly probable diagnosis of the main cause of the syncope. AoS was considered the primary cause of the syncope in only 7 patients (17.5% of the patients with known etiology). Atrioventricular block (14 patients, 35.0%) and vasovagal syncope (6 patients, 15.0%) were the most frequently diagnosed causes. The presence of a known cause for syncope during the admission was not associated with a lower incidence of recurrence during follow-up (hazard ratio [HR] 0.69, 95% confidence interval [CI] 0.20-2.40). Syncope of unknown etiology was independently associated with greater mortality during 1-year follow-up (HR 5.4, 95% CI 1.3-21.6) and 3-year follow-up (HR 3.5, 95% CI 1.2-10.3).ConclusionsIn a high proportion of patients with severe AoS admitted for syncope, the valvulopathy was not the main cause of the syncope. Syncope in two-thirds of this population was caused by either bradyarrhythmia or reflex causes. Syncope of unknown cause was associated with increased short- and medium-term mortality, independently from treatment of the valve disease. An exhaustive work-up should be conducted to determine the main cause for syncope. 相似文献
34.
The information gathered here helps to explain why risk factors in the development of VAP vary from series to series. It also explains why different investigators have found opposite effects when evaluating the antibiotics. Antibiotic therapy has a bimodal effect in the development of VAP. Antibiotics protect against pneumonia development within the first days of MV, especially against types caused by endogenous flora, but they are responsible for selection of a set of resistant pathogens that are associated with significant attributable mortality, such as P aeruginosa and MRSA. These observations suggest that risk factors vary depending on the exposure to risk (ie, length of stay or MV). This variable should be considered when stratifying patients for risk factor analysis and also in the design of clinical trials for VAP prophylaxis. 相似文献
35.
Silvia Barril Ana Alonso José Antonio Rodríguez-Portal Margarita Viladot Jordi Giner Francisco Aparicio Ana Romero-Ortiz Orlando Acosta Diego Castillo 《Archivos de bronconeumología》2018,54(3):123-127
Introduction
Interstitial lung diseases (ILD) and, in particular, idiopathic pulmonary fibrosis, may have a significant impact on patient survival. Recent studies highlight the need for palliative care (PC) in the management of ILD patients. The aim of this study was to determine the current situation of PC in patients in Spain.Methods
A 36-question survey addressing the main aspects of PC in ILD patients was designed. The survey was sent via email to all members of the Spanish Society of Pulmonology and Thoracic Surgery. Participation was voluntary.Results
One hundred and sixty-four participants responded to the survey. Ninety-eight percent said they were interested in PC, 46% had received specific training, and 44% reported being responsible for PC in their ILD patients. Symptom control and end-of-life stage were the most frequent reasons for referral to PC teams. Regarding end-of-life, 78% reported consensual agreement with patients on the limitation of therapeutic efforts, 35% helped prepare an end-of-life advance directive, and 22% agreed on the place of death.Conclusion
Despite the well-known need for PC in patients with ILD and the notable interest of the survey participants in this subject, there are clear formative and organizational gaps that should be addressed to improve care in this area in ILD patients in Spain. 相似文献36.
Zdzisław Świderski Jordi Miquel Isabel Montoliu Carlos Feliu David I. Gibson 《Parasitology research》2013,112(9):3325-3333
Intrauterine embryonic development in the microphallid trematode Maritrema feliui is examined by means of transmission electron microscopy. Both fertilization and eggshell formation take place in the ootype. The eggshell is formed from a shell globule material derived from the vitelline cells combined with secretions of Mehlis' gland. The proximal uterus is packed with unembryonated eggs of the oligolecithal type, each composed of a fertilized oocyte and several vitelline cells, all surrounded by the shell. Intrauterine embryonic development of the egg is followed to the early stage of outer embryonic envelope formation, resulting in an embryo of ~20 blastomeres of three different types: macromeres, mesomeres and micromeres. The first equal cleavage division of the zygote produces two macromeres. The outer envelope is of cellular origin and formed by the cytoplasmic fusion of two macromeres, which become situated at opposite poles in the peripheral layer of the embryo just beneath the eggshell. Simultaneously, other blastomeres multiply and differentiate, whereas several micromeres exhibit clear signs of degeneration or apoptosis. These results show that the embryonic development of M. feliui starts in utero and represents an example of early stage ovoviviparity. A reduction in the number of blastomeres results from a continued degeneration of micromeres, which after autolysis and re-absorption, appear to represent an important source of nutritive reserves for the embryo. The embryonic development of this digenean is discussed in relation to its life cycle. 相似文献
37.
Turjeman Adi Babich Tanya Pujol Miquel Carratalà Jordi Shaw Evelyn Gomila-Grange Aina Vuong Cuong Addy Ibironke Wiegand Irith Grier Sally MacGowan Alasdair Vank Christiane Cuperus Nienke van den Heuvel Leo Leibovici Leonard Eliakim-Raz Noa 《European journal of clinical microbiology & infectious diseases》2021,40(9):2005-2010
European Journal of Clinical Microbiology & Infectious Diseases - Complicated urinary tract infection (cUTI) is a frequent cause of morbidity. In this multinational retrospective cohort study,... 相似文献
38.
39.
Zdzisław Świderski Isabel Montoliu Carlos Feliu David I. Gibson Jordi Miquel 《Acta parasitologica / Witold Stefański Institute of Parasitology, Warszawa, Poland》2013,58(4):478-485
The tegument of the microphallid digenean Maritrema feliui, examined by means of TEM, is described as a syncytial epithelium organised into two layers. The outer layer is an external anucleate, cytoplasmic region connected to a second region composed of nucleate perikarya (cytons) deeply embedded in the surrounding cortical parenchyma. The surface layer of the tegument is covered by a plasma membrane with many deep invaginations, which are apparently pinocytotic. This layer also bears numerous large, electron-dense spines of two types, which are intracellular and attached to the basal plasma membrane. Its cytoplasm is rich in free ribosomes, contains numerous mitochondria, disc-shaped granules frequently arranged in a rouleau, and several large, moderately electron-dense, membranous bodies. The subtegumentary perikarya and their nuclei, which are both flattened, are described in detail, as are their connections with the surface tegument. These perikarya appear to be the source of the disc-shaped granules and some of the other inclusions present in the surface layer. The main characteristics of the tegumental structure of M. feliui are commented upon in relation to the findings of previous publications and their suggested functions. 相似文献
40.
Albert Parés MD Jaime Martorell MD Joan Caballería MD Jordi Vives MD Miquel Bruguera MD Joan Rodés MD 《Digestive diseases and sciences》1985,30(9):829-833
Sera of 30 patients with primary biliary cirrhosis (PBC) and 72 normal subjects matched for age and sex were examined for the presence of lymphocytotoxic antibodies (LCAs) against B and T cells at 4° C and 37° C. Patients were prospectively screened for: Sjögren's syndrome, scleroderma, Hashimoto's thyroiditis, and rheumatoid arthritis, in which LCAs have been described. Seventeen patients with PBC (56.6%) had LCAs against B cells as compared with only 11 of the 72 normal subjects (P<0.001). Five PBC patients (16.6%) also reacted against T cells as compared with none in control group (P<0.01). Clinical and biochemical features and the histological stage of PBC were similar in patients with and without LCA. Sjögren's syndrome was present in 13 patients—two with scleroderma and another with Hashimoto's thyroiditis. No patient had rheumatoid arthritis. The prevalence of LCAs was similar in PBC patients with or without autoimmune associated disease (54% vs 59%). We conclude that in PBC a high incidence of LCA is unrelated to the presence of an associated disease. LCA in PBC might be a nonspecific marker of an immune disorder. 相似文献