全文获取类型
收费全文 | 9446篇 |
免费 | 673篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 124篇 |
儿科学 | 293篇 |
妇产科学 | 265篇 |
基础医学 | 1554篇 |
口腔科学 | 287篇 |
临床医学 | 942篇 |
内科学 | 1965篇 |
皮肤病学 | 223篇 |
神经病学 | 795篇 |
特种医学 | 268篇 |
外科学 | 915篇 |
综合类 | 75篇 |
一般理论 | 5篇 |
预防医学 | 999篇 |
眼科学 | 124篇 |
药学 | 610篇 |
中国医学 | 14篇 |
肿瘤学 | 694篇 |
出版年
2023年 | 68篇 |
2022年 | 128篇 |
2021年 | 309篇 |
2020年 | 178篇 |
2019年 | 254篇 |
2018年 | 269篇 |
2017年 | 231篇 |
2016年 | 243篇 |
2015年 | 264篇 |
2014年 | 302篇 |
2013年 | 463篇 |
2012年 | 733篇 |
2011年 | 700篇 |
2010年 | 399篇 |
2009年 | 335篇 |
2008年 | 622篇 |
2007年 | 646篇 |
2006年 | 559篇 |
2005年 | 591篇 |
2004年 | 473篇 |
2003年 | 438篇 |
2002年 | 382篇 |
2001年 | 108篇 |
2000年 | 98篇 |
1999年 | 103篇 |
1998年 | 70篇 |
1997年 | 65篇 |
1996年 | 58篇 |
1995年 | 54篇 |
1994年 | 50篇 |
1993年 | 52篇 |
1992年 | 74篇 |
1991年 | 66篇 |
1990年 | 60篇 |
1989年 | 48篇 |
1988年 | 54篇 |
1987年 | 45篇 |
1986年 | 40篇 |
1985年 | 39篇 |
1984年 | 30篇 |
1983年 | 27篇 |
1980年 | 28篇 |
1979年 | 28篇 |
1978年 | 25篇 |
1976年 | 21篇 |
1975年 | 20篇 |
1974年 | 24篇 |
1973年 | 25篇 |
1972年 | 24篇 |
1971年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
1.
Spread of an Enterococcus faecalis sequence type 6 (CC2) clone in patients undergoing selective decontamination of the digestive tract
下载免费PDF全文
![点击此处可从《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Izaskun Muruzábal‐Lecumberri Cecilia Girbau Andrés Canut Rodrigo Alonso Aurora Fernández‐Astorga 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2015,123(3):245-251
Enterococcus faecalis (E. faecalis) is a common cause of nosocomial infection in immunocompromised patients. The presence and dissemination of high‐risk clonal complexes, such as CC2, is an ongoing problem in hospitals. The aim of this work was to characterize 24 E. faecalis isolates from ICU patients undergoing selective decontamination of the digestive tract (SDD) by phenotypical (antimicrobial susceptibility) and genotypical (presence of virulence genes, RAPD‐PCR and MLST) methods. Our results showed high prevalence of the ST6 E. faecalis clone (91.6%), especially adapted to the hospital environment, with a multidrug resistance pattern and a multitude of putative virulence genes. In addition, ST179 (4.2%) and ST191 (4.2%) were detected. By RAPD–PCR analysis, the 22 isolates identified as ST6 showed six different DNA patterns, while the two remaining isolates, ST179 and ST191, showed two additional profiles. CC2 is a known clonal complex with high adaptability to hospital environment and worldwide distribution. The high prevalence of the ST6 clone in the studied population could be related to the presence of gentamicin in the SDD mixture since most strains were gentamicin resistant. Consequently, strict surveillance should be applied for rapid detection and control of this clone to prevent future spread outside the ICU. 相似文献
2.
Auda A. Eltahla Fabio Luciani Peter A. White Andrew R. Lloyd Rowena A. Bull 《Viruses》2015,7(10):5206-5224
The hepatitis C virus (HCV) is a pandemic human pathogen posing a substantial health and economic burden in both developing and developed countries. Controlling the spread of HCV through behavioural prevention strategies has met with limited success and vaccine development remains slow. The development of antiviral therapeutic agents has also been challenging, primarily due to the lack of efficient cell culture and animal models for all HCV genotypes, as well as the large genetic diversity between HCV strains. On the other hand, the use of interferon-α-based treatments in combination with the guanosine analogue, ribavirin, achieved limited success, and widespread use of these therapies has been hampered by prevalent side effects. For more than a decade, the HCV RNA-dependent RNA polymerase (RdRp) has been targeted for antiviral development. Direct acting antivirals (DAA) have been identified which bind to one of at least six RdRp inhibitor-binding sites, and are now becoming a mainstay of highly effective and well tolerated antiviral treatment for HCV infection. Here we review the different classes of RdRp inhibitors and their mode of action against HCV. Furthermore, the mechanism of antiviral resistance to each class is described, including naturally occurring resistance-associated variants (RAVs) in different viral strains and genotypes. Finally, we review the impact of these RAVs on treatment outcomes with the newly developed regimens. 相似文献
3.
Rosario Fernández-Plata Rogelio Pérez-Padilla Rodrigo Del Río-Hidalgo Cecilia García-Sancho Laura Gochicoa-Rangel Christian Rodríguez-Hernández Luis Torre-Bouscoulet David Martínez-Briseño 《Archivos de bronconeumología》2019,55(10):513-518
IntroductionPeople with Down syndrome (DS) have high respiratory morbidity, evaluating their respiratory health with standardized, objective tests is desirable. Thus, the objective of this study was to evaluate the technical quality of Pulmonary Function Tests (PFTs) to determine which ones are most suitable for this population.MethodsParticipants included children, teenagers and adults with DS, 5 years of age or older (n = 302). The technical quality of the impulse oscillometry system (IOS), forced spirometry, lung-diffusing capacity for carbon monoxide (DLCO), and 6-min walk test (6MWT) were analyzed by age group. Capnography and pulse oximetry were included in the study. Technical quality was determined on the basis of current international PFTs standards.ResultsFifty-one percent of participants were males. A total of 184 participants (71%) who completed the IOS fulfilled the quality criteria, while 210 (70%) completed the 6MWT. Performance on forced spirometry and DLCO was poor. All pulse oximetries and 96% percent heart rates obtained had good quality, but exhaled carbon dioxide (PetCO2) and respiratory rate (RR) showed deficient repeatability.ConclusionsIOS appears to be the most reliable instrument for evaluating lung mechanics in individuals with DS. 相似文献
4.
5.
Jennifer L. Brown Lisa B. Haddad Nicole K. Gause Sarah Cordes Cecilia Bess Caroline C. King 《Women & health》2019,59(3):305-317
This study qualitatively examined factors that influenced contraceptive choices in a sample of young, HIV-infected women. Individual qualitative interviews were conducted among 30 vertically and horizontally HIV-infected women (n = 26 African American) from the ages of 14 to 24 years (Mean age = 20.9 years). We recruited sample groups with the following characteristics: (a) current contraceptive/condom use with ≥1 child (n = 11); (b) current contraceptive/condom use with no children (n = 12); and (c) no current contraceptive/condom use with no children (n = 7). A semi-structured interview guide was used to ask participants about factors influencing past and current contraceptive choices. Individual interviews were digitally recorded and transcribed verbatim; analyses to identify core themes were informed by the Grounded Theoretical approach. Young, HIV-infected women did not identify their HIV serostatus or disease-related concerns as influential in their contraceptive decisions. However, they reported that recommendations from health-care providers and input from family and friends influenced their contraceptive choices. They also considered a particular method’s advantages (e.g., menstrual cycle improvements) and disadvantages (e.g., increased pill burden) when selecting a method. Findings suggested that HIV-infected young women’s contraceptive decisions were influenced by factors other than those related to their infection. 相似文献
6.
Luana Lopes Padilha Elcio Oliveira Vianna Andressa Talícia Machado Vale Joelma Ximenes Prado Teixeira Nascimento Antônio Augusto Moura da Silva Cecilia Claudia Costa Ribeiro 《Pediatric allergy and immunology》2020,31(5):480-488
Studies on the exposure of children to sugar-sweetened beverages (SSBs) at an early age may contribute to better understand the common causes and the temporal order of the relationships between obesity and asthma in early childhood. The objective of this study was to estimate the association between SSB and child asthma traits in the 2nd year of life, modeling direct and indirect pathways mediated by the highest BMI-z of the child and allergic inflammation. Data from the BRISA cohort, São Luís-MA, Brazil (n = 1140), were obtained from the baseline and from the follow-up performed at the 2nd year of life. The main explanatory variable was the calories from added sugars in SSBs as a percentage of the total daily energy intake. The outcome child asthma traits was a latent variable deduced from four indicators: medical diagnosis of asthma, wheezing, emergency visit due to intense wheezing, and medical diagnosis of rhinitis. A high percentage of daily calories from sugars added to SSBs was directly associated with higher values of child asthma traits (standardized coefficient (SC = 0.073; P = .030)). High levels of eosinophils were also directly associated with child asthma traits (SC = 0.118; P = .049). No mediation pathways were observed via greater BMI-z or eosinophil counts. Therefore, early exposure of children to SSB may contribute to increased risk of childhood asthma, preceding the link between sugar consumption and overweight/obesity, not yet evident in children in the first 2 years of life. 相似文献
7.
Attila Szalmas Peter Bodrogi Cecilia Sik-Lanyi 《Ophthalmic & physiological optics》2006,26(3):281-287
The objective of this study is to test the luminous efficiency functions V(lambda), V'(lambda), V(10)(lambda) and their linear combinations on the basis of a data set gained from a simulated mesopic night-time driving experiment. Another aim is to provide 'real-world' data for the 'X framework' or 'linear combination model', and to find out its limits in a practical situation. Human performance was measured by the reaction time method. Results show that the single parameter of the linear combination of photopic and scotopic luminous efficiency functions can be determined analytically with little variation for a given mesopic background luminance level and a given visual target colour, but the computation leads to considerable deviations comparing all three target colours (red, green and blue) used in the experiment. The conclusion for the given experimental conditions is that the single parameter of the linear combination model has an increasing deviation for lower background luminance levels. 相似文献
8.
9.
Roberto H. Caraballo Laura Gañez Cecilia De los Santos Alberto Espeche Ricardo Cersósimo Natalio Fejerman 《Seizure》2009,18(10):686-689
PurposeTo analyze the electroclinical features, aetiology and outcome in patients with normal neurological examination and psychomotor development who presented seizures during a mild gastroenteritis (MG).Patients and methodsEvaluation of the clinical charts of 22 patients who were assessed in the Neurology Department, Hospital Nacional de Pediatría Prof. Dr. JP Garrahan between 1999 and 2007.ResultsTwelve patients were boys and 10 were girls, the age of onset ranged from 5 to 26 months, and the median age was 10 months. Rotavirus antigen test in stool was positive in 9 of 18 studied patients. The seizures were brief, focal with secondary generalization in 15 patients (68.5%), apparently generalized in 5 (22.5%) and focal in two (9%). Seven of the patients (35%) had more than one seizure in 24 h. The interictal EEG was normal in all patients. Neuroradiological studies were performed in 19 patients with a normal result. No patient was put on long-term treatment with antiepileptic drugs. Four patients had subsequent mild gastroenteritis and two of them presented convulsions during the disease. After between 12 and 67 months of follow-up, all patients had normal psychomotor development and neurological examination.ConclusionsIn this study we confirmed the association of benign infantile seizures (BIS) and MG with or without rotavirus. The identification of this entity allows avoiding unnecessary complementary studies and treatment with antiepileptic drugs. 相似文献
10.
With the advent of computerized databases, medical data has become easy to accumulate; however, effective use of this data continues to pose significant problems. In other circumstances, smoothing algorithms have been used to uncover non-obvious correlations, trends and relationships in noisy data. We have applied four such algorithms to a large dataset of postoperative blood replacement in cardiopulmonary bypass patients. When applied to this dataset, one of the algorithms proved surprisingly effective. It confirmed several previously observed correlations, and also provided an additional series of counterintuitive and apparently unrelated associations. These associations have been explored in an accompanying paper. 相似文献