全文获取类型
收费全文 | 4799篇 |
免费 | 238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 | 514篇 |
口腔科学 | 84篇 |
临床医学 | 587篇 |
内科学 | 1460篇 |
皮肤病学 | 53篇 |
神经病学 | 576篇 |
特种医学 | 90篇 |
外科学 | 421篇 |
综合类 | 13篇 |
预防医学 | 455篇 |
眼科学 | 33篇 |
药学 | 357篇 |
中国医学 | 3篇 |
肿瘤学 | 277篇 |
出版年
2024年 | 5篇 |
2023年 | 21篇 |
2022年 | 67篇 |
2021年 | 179篇 |
2020年 | 92篇 |
2019年 | 157篇 |
2018年 | 199篇 |
2017年 | 117篇 |
2016年 | 118篇 |
2015年 | 126篇 |
2014年 | 217篇 |
2013年 | 261篇 |
2012年 | 416篇 |
2011年 | 431篇 |
2010年 | 262篇 |
2009年 | 212篇 |
2008年 | 323篇 |
2007年 | 304篇 |
2006年 | 312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5055条查询结果,搜索用时 187 毫秒
71.
Iris?Iglesia Isabelle?Guelinckx Pilar?M.?De?Miguel-Etayo Esther?M.?González-Gil Jordi?Salas-Salvadó Stavros?A.?Kavouras Joan?Gandy Homero?Martínez Saptawati?Bardosono Morteza?Abdollahi Esmat?Nasseri Agnieszka?Jarosz Guansheng?Ma Esteban?Carmuega Isabelle?Thiébaut Luis?A.?MorenoEmail author 《European journal of nutrition》2015,54(2):57-67
Purpose
To describe total fluid intake (TFI) according to socio-demographic characteristics in children and adolescents worldwide.Methods
Data of 3611 children (4–9 years) and 8109 adolescents (10–18 years) were retrieved from 13 cross-sectional surveys (47 % males). In three countries, school classes were randomly recruited with stratified cluster sampling design. In the other countries, participants were randomly recruited based on a quota method. TFI (drinking water and beverages of all kinds) was obtained with a fluid-specific record over 7 consecutive days. Adequacy was assessed by comparing TFI to 80 % of adequate intake (AI) for total water intake set by European Food Safety Authority. Data on height, weight and socio-economic level were collected in most countries.Results
The mean (SD) TFI ranged from [1.32 (0.68)] to [1.35 (0.71)] L/day. Non-adherence to AIs for fluids ranged from 10 % (Uruguay) to >90 % (Belgium). Females were more likely to meet the AIs for fluids than males (4–9 years: 28 %, OR 0.72, p = 0.002; 10–18 years: 20 %, OR 0.80, p = 0.001), while adolescents were less likely to meet the AI than children (OR 1.645, p < 0.001 in males and OR 1.625, p < 0.001 in females).Conclusions
A high proportion of children and adolescents are at risk of an inadequate fluid intake. This risk is especially high in males and adolescents when compared with females or children categories. This highlights water intake among young populations as an issue of global concern.72.
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
73.
McMurray J Cohen-Solal A Dietz R Eichhorn E Erhardt L Hobbs FD Krum H Maggioni A McKelvie RS Piña IL Soler-Soler J Swedberg K 《European journal of heart failure》2005,7(5):710-721
Surveys of prescribing patterns in both hospitals and primary care have usually shown delays in translating the evidence from clinical trials of pharmacological agents into clinical practice, thereby denying patients with heart failure (HF) the benefits of drug treatments proven to improve well-being and prolong life. This may be due to unfamiliarity with the evidence-base for these therapies, the clinical guidelines recommending the use of these treatments or both, as well as concerns regarding adverse events. ACE inhibitors have long been the cornerstone of therapy for systolic HF irrespective of aetiology. Recent trials have now shown that treatment with beta-blockers, aldosterone antagonists and angiotensin receptor blockers also leads to substantial improvements in outcome. In order to accelerate the safe uptake of these treatments and to ensure that all eligible patients receive the most appropriate medications, a clear and concise set of clinical recommendations has been prepared by a group of clinicians with practical expertise in the management of HF. The objective of these recommendations is to provide practical guidance for non-specialists, in order to increase the use of evidenced based therapy for HF. These practical recommendations are meant to serve as a supplement to, rather than replacement of, existing HF guidelines. 相似文献
74.
We conducted the current study to analyze the prevalence and clinical significance of circulating monoclonal immunoglobulins in patients with Sj?gren syndrome (SS), focusing on the association with extraglandular features, immunologic markers, hematologic neoplasia, and hepatitis C virus (HCV) infection. We performed serum immunoelectrophoresis in 200 patients with primary SS and 37 patients with HCV-related SS. All patients fulfilled 4 or more of the 1993 European classification criteria for SS.Of the 200 patients with primary SS, 35 (18%) presented circulating monoclonal immunoglobulins. The monoclonal bands identified were 20 IgG (13 kappa, 7 lambda), 10 IgM (5 kappa, 5 lambda), 2 IgAkappa, and 3 free circulating light chains. Of the 37 SS-HCV patients, 16 (43%) had circulating monoclonal immunoglobulins. The monoclonal bands identified were 10 IgMkappa, 5 IgGlambda, and 1 free light lambda chain. Compared with primary SS patients, SS-HCV patients presented a higher frequency of monoclonal immunoglobulins (43% vs 18%, p = 0.001), with monoclonal IgMkappa being the most frequent monoclonal band. Six (12%) of the 51 SS patients with circulating monoclonal immunoglobulins presented hematologic neoplasia, compared with 3 (1.6%) of those without monoclonal immunoglobulins (p = 0.004; odds ratio = 8.13; 95% confidence intervals, 1.64-51.54). In 2 of the 6 patients with monoclonal immunoglobulins and lymphoproliferative disorders, a change of the monoclonal component was detected in previous immunoelectrophoresis determinations before the development of hematologic neoplasia. Circulating monoclonal immunoglobulins were detected in nearly 20% of patients with primary SS, with monoclonal IgG being the most frequent type of immunoglobulin detected. In SS-HCV patients, the prevalence of monoclonal immunoglobulins was higher (43%), with monoclonal IgM being the most frequent type found. SS-HCV patients presented a more restrictive monoclonal expression (limited to either monoclonal IgMkappa or monoclonal IgGlambda) than primary SS patients, who showed all types of heavy and light chains. 相似文献
75.
A study of prognostic factors in blast crisis of Philadelphia chromosome-positive chronic myelogenous leukaemia 总被引:1,自引:0,他引:1
Francisco Cervantes María Rozman Jordi Rosell Alvaro Urbano-Ispizua† Emilio Montserrat Ciril Rozman 《British journal of haematology》1990,76(1):27-32
In 80 patients with Ph-positive chronic myelogenous leukaemia the main clinical, haematological and cytogenetical data were recorded at diagnosis of blast crisis and evaluated for prognostic significance. At the time of the analysis 73 patients had died, with a median survival of 4-8 months from diagnosis of blast crisis for the whole series. When analysed as a time-dependent variable, the achievement of a favourable response to chemotherapy resulted in a longer patient's survival. On the other hand, the univariate analysis identified six pretreatment characteristics associated with a poorer prognosis: a longer chronic phase, presence of extramedullary blastic involvement, a platelet count below 200 x 10(9)/l, a less marked leucocytosis, a blood blast cell percentage higher than 10%, and presence of trisomy 8. The latter parameters were included in a multiple regression model together with the blast cell phenotype (lymphoid versus non-lymphoid), and only four of them (trisomy 8, duration of chronic phase, platelet count, and leucocyte count) retained their prognostic influence. When the therapeutical response was also included in the regression model, it proved to be the most important prognostic variable, followed by trisomy 8, length of chronic phase, extramedullary disease, and platelet count, whereas the leukocyte count lost its predictive value. Thus, in spite of the short overall survival of blast crisis patients, the identification of prognostic factors in such a haematological condition may be of interest, especially in the interpretation of new therapeutical approaches. 相似文献
76.
OBJECTIVE: Patients with unexplained abdominal complaints often attribute their symptoms to intestinal gas and indicate that symptoms are exacerbated by ingestion of a meal. However, the mechanisms responsible are unknown. Our aim was to analyze the specific influence of two meal-related factors, gastric distension, and intestinal nutrients, on intestinal gas dynamics and tolerance. METHODS: In 35 healthy subjects, gas evacuation and perception of jejunal gas infusion (12 ml/min) were measured for 3 h, during simultaneous duodenal infusion of saline, as control, lipids at 1 Kcal/min, or gastric distension. RESULTS: Infusion of lipids into the duodenum induced gas retention (584 +/- 154 ml, p < 0.05 vs 161 +/- 86 ml after saline infusion) without perception (2.2 +/- 0.5 score), whereas gastric distension induced perception (score 5.6 +/- 0.4, p < 0.05 vs score 1.9 +/- 0.4 after saline) without gas retention (7 +/- 205 ml). CONCLUSIONS: Different meal-related factors exert specific effects on intestinal gas dynamics and tolerance, and these mechanisms may interact to produce postprandial gas symptoms. 相似文献
77.
Sánchez-Quesada JL Camacho M Antón R Benítez S Vila L Ordóñez-Llanos J 《Atherosclerosis》2003,166(2):261-270
Electronegative LDL (LDL(-)) constitutes a plasma subfraction of LDL with proinflammatory properties. Its proportion is increased in familial hypercholesterolemia (FH); however, the characteristics of LDL(-) isolated from FH subjects have not been previously studied. In this work, the composition, oxidative status, and inflammatory capacity on endothelial cells of LDL(-) from FH and normolipemic (NL) subjects were evaluated. LDL(-) from FH was relatively enriched in esterified and free cholesterol and triglyceride, and had lower apoB and phospholipid content compared with the non-electronegative fraction (LDL(+)). LDL(-) also contained increased amounts of apoE, apoC-III, sialic acid, and non-esterified fatty acids (NEFAs). The same was observed in NL subjects, except that esterified cholesterol and phospholipid were similar in LDL(-) and LDL(+). No difference was observed between the two fractions concerning malondialdehyde, fatty acid hydroxides, and antioxidants, thereby indicating the absence of increased oxidation of LDL(-) compared with LDL(+). When LDL(-) (100 mg/l) from NL and FH subjects was incubated for 24 h with human umbilical vein endothelial cells (HUVECs), interleukin 8 (IL-8) and monocyte chemotactic protein 1 (MCP-1) increased twofold in the culture medium compared with LDL(+). Vascular cell adhesion molecule 1 (VCAM-1) expression was not increased by LDL(-). Our data indicate that LDL(-) from FH or NL subjects shows no evidence of increased oxidative modification compared to LDL(+); however, LDL(-) induces twofold the release of chemokines by endothelial cells. This effect, which may contribute to leukocyte recruitment and promote atherogenesis, may be greater in FH subjects in which LDL(-) can be up to eightfold higher than in NL subjects. 相似文献
78.
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
79.
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80.
Gutschmidt Kristina Musumeci Olimpia Díaz-Manera Jordi Chien Yin-Hsiu Knop Karl Christian Wenninger Stephan Montagnese Federica Pugliese Alessia Tavilla Graziana Alonso-Pérez Jorge Hwu Paul Wuh-Liang Toscano Antonio Schoser Benedikt 《Journal of neurology》2021,268(7):2482-2492
Journal of Neurology - Pompe disease is one of the few neuromuscular diseases with an approved drug therapy, which has been available since 2006. Our study aimed to determine the real-world... 相似文献