全文获取类型
收费全文 | 174863篇 |
免费 | 8036篇 |
国内免费 | 413篇 |
专业分类
耳鼻咽喉 | 2246篇 |
儿科学 | 5609篇 |
妇产科学 | 3584篇 |
基础医学 | 23510篇 |
口腔科学 | 7627篇 |
临床医学 | 12780篇 |
内科学 | 38814篇 |
皮肤病学 | 4449篇 |
神经病学 | 14306篇 |
特种医学 | 5533篇 |
外国民族医学 | 26篇 |
外科学 | 21207篇 |
综合类 | 1448篇 |
现状与发展 | 1篇 |
一般理论 | 60篇 |
预防医学 | 17895篇 |
眼科学 | 3219篇 |
药学 | 10439篇 |
3篇 | |
中国医学 | 691篇 |
肿瘤学 | 9865篇 |
出版年
2023年 | 944篇 |
2022年 | 1969篇 |
2021年 | 3674篇 |
2020年 | 2546篇 |
2019年 | 3529篇 |
2018年 | 4849篇 |
2017年 | 3630篇 |
2016年 | 3378篇 |
2015年 | 3955篇 |
2014年 | 5412篇 |
2013年 | 6887篇 |
2012年 | 10634篇 |
2011年 | 11115篇 |
2010年 | 5637篇 |
2009年 | 5067篇 |
2008年 | 8601篇 |
2007年 | 9234篇 |
2006年 | 8570篇 |
2005年 | 8834篇 |
2004年 | 8318篇 |
2003年 | 7599篇 |
2002年 | 5651篇 |
2001年 | 4970篇 |
2000年 | 4963篇 |
1999年 | 4381篇 |
1998年 | 1617篇 |
1997年 | 1371篇 |
1996年 | 1371篇 |
1995年 | 1144篇 |
1994年 | 1141篇 |
1993年 | 1049篇 |
1992年 | 2687篇 |
1991年 | 2594篇 |
1990年 | 2373篇 |
1989年 | 2398篇 |
1988年 | 2160篇 |
1987年 | 2001篇 |
1986年 | 1876篇 |
1985年 | 1789篇 |
1984年 | 1310篇 |
1983年 | 1036篇 |
1982年 | 596篇 |
1981年 | 549篇 |
1980年 | 541篇 |
1979年 | 943篇 |
1978年 | 631篇 |
1977年 | 509篇 |
1975年 | 579篇 |
1974年 | 547篇 |
1973年 | 542篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
ABSTRACTThe clinicoanatomic cases of acquired pedophilia that have been published in the medical and forensic literature up to 2019 are reviewed. Twenty-two cases fit our inclusion criteria. All but one were men, and in only one case the injury was localized to the left hemisphere. Hypersexuality was present in 18 cases. The damaged areas fell within the frontotemporoinsular cortices and related subcortical nuclei; however, the anterior hypothalamus was spared. Damage to parts of the right frontotemporoinsular lobes with sparing of the anterior hypothalamus seems to be critical for the emergence of acquired pedophilia. 相似文献
12.
AbstractTeaching and learning practices often fail to incorporate new concepts in the ever-evolving field of medical education. Although medical education research provides new insights into curricular development, learners’ engagement, assessment methods, professional development, interprofessional education, and so forth, faculty members often struggle to modernize their teaching practices. Communities of practice (CoP) for faculty development offer an effective and sustainable approach for knowledge management and implementation of best practices. A successful CoP creates and shares knowledge in the context of a specific practice toward the development of expertise. CoPs’ collaborative nature, based on the co-creation of practical solutions to daily problems, aligns well with the goals of applying best practices in health professions education and training new faculty members. In our article, we share 12 tips for implementing a community of practice for faculty development. The tips were based on a comprehensive literature review and the authors’ experiences. 相似文献
13.
Otavio Berwanger Renato D. Lopes Diogo D.F. Moia Francisco A. Fonseca Lixin Jiang Shaun G. Goodman Stephen J. Nicholls Alexander Parkhomenko Oleg Averkov Carlos Tajer Germán Malaga Jose F.K. Saraiva Helio P. Guimaraes Pedro G.M. de Barros e Silva Lucas P. Damiani Renato H.N. Santos Denise M. Paisani Tamiris A. Miranda Jose C. Nicolau 《Journal of the American College of Cardiology》2019,73(22):2819-2828
BackgroundThe efficacy of ticagrelor in the long-term post–ST-segment elevation myocardial infarction (STEMI) treated with fibrinolytic therapy remains uncertain.ObjectivesThe purpose of this study was to evaluate the efficacy of ticagrelor when compared with clopidogrel in STEMI patients treated with fibrinolytic therapy.MethodsThis international, multicenter, randomized, open-label with blinded endpoint adjudication trial enrolled 3,799 patients (age <75 years) with STEMI receiving fibrinolytic therapy. Patients were randomized to ticagrelor (180-mg loading dose, 90 mg twice daily thereafter) or clopidogrel (300- to 600-mg loading dose, 75 mg daily thereafter). The key outcomes were cardiovascular mortality, myocardial infarction, or stroke, and the same composite outcome with the addition of severe recurrent ischemia, transient ischemic attack, or other arterial thrombotic events at 12 months.ResultsThe combined outcome of cardiovascular mortality, myocardial infarction, or stroke occurred in 129 of 1,913 patients (6.7%) receiving ticagrelor and in 137 of 1,886 patients (7.3%) receiving clopidogrel (hazard ratio: 0.93; 95% confidence interval: 0.73 to 1.18; p = 0.53). The composite of cardiovascular mortality, myocardial infarction, stroke, severe recurrent ischemia, transient ischemic attack, or other arterial thrombotic events occurred in 153 of 1,913 patients (8.0%) treated with ticagrelor and in 171 of 1,886 patients (9.1%) receiving clopidogrel (hazard ratio: 0.88; 95% confidence interval: 0.71 to 1.09; p = 0.25). The rates of major, fatal, and intracranial bleeding were similar between the ticagrelor and clopidogrel groups.ConclusionAmong patients age <75 years with STEMI, administration of ticagrelor after fibrinolytic therapy did not significantly reduce the frequency of cardiovascular events when compared with clopidogrel. (Ticagrelor in Patients With ST Elevation Myocardial Infarction Treated With Pharmacological Thrombolysis [TREAT]; NCT02298088) 相似文献
14.
Kamila Pires de Carvalho Mariana Tavares Miranda Lima Fernanda Silva Mazzutti Isis Danyelle Dias Custódio Paula Philbert Lajolo Canto Carlos Eduardo Paiva Yara Cristina de Paiva Maia 《Clinical breast cancer》2019,19(1):e208-e219
Purpose
To study the use of functional capacity (FC) level and duration of aromatase inhibitor (AI) therapy with adiposity parameters in women with breast cancer.Patients and Methods
FC was evaluated through the Health Assessment Questionnaire, which was assessed by classification and divided into 3 groups: G1 = mild to moderate difficulty, G2 = moderate to severe disability, and G3 = severe or very severe disability. Body mass, height, and waist circumference (WC) were measured, and body mass index (BMI) was calculated. Bioelectrical impedance analysis was used to calculate body fat (BF) and fat-free mass. The women were divided into 2 time groups (T1 and T2), which were determined by the median months of AI use (T1 ≤ 29.5 and T2 > 29.5 months).Results
Impaired FC and adiposity parameters were significantly positively correlated. In addition, physical exercise was significantly lower in women assessed as G2 and G3 compared to those assessed as G1. The effect of FC on BMI, BF, and WC was also verified, as was the effect of the duration of AI receipt on BMI and BF. Women at T1 had significantly greater functional disability, BMI, and BF values. In addition, although not statistically significant, women in T1 who were assessed as G3 presented higher BMI, WC, and BF values than those in T2.Conclusion
Adiposity above the recommended parameters and impaired FC were associated with the shortest time of receipt of adjuvant endocrine therapy with AI. 相似文献15.
Edward J.A. Harris Steven Kao Brian McCaughan Takashi Nakano Nobuyuki Kondo Rebecca Hyland Anna K. Nowak Nicholas H. de Klerk Fraser J.H. Brims 《Journal of thoracic oncology》2019,14(2):288-293
Introduction
Malignant pleural mesothelioma (MPM) is an uncommon cancer with a poor prognosis and heterogeneous survival. Surgery for MPM is offered in some specialist centers to highly selected patients. A previously described classification and regression tree (CART) model stratified survival in unselected MPM patients using routinely collected clinical data. This study aimed to examine the performance of this CART model on a highly selected surgical population.Methods
Data were collected from subjects undergoing cytoreductive surgery for MPM from specialist centers in Hyõgo, Japan, and Sydney, Australia, between 1991 and 2016. The CART model was applied using the combination of clinical variables to stratify subjects into risk groups (1 through 4); survival characteristics were then compared.Results
Two hundred eighty-nine cases were included (205 from Australia, 84 from Japan). Overall median survival was 34.6 (interquartile range: 17.5–56.1) months; median age was 63.0 (interquartile range: 57.0–67.8) years, and 83.0% (n = 240) were male. There were no clinically meaningful differences between the two cohorts. Survival across the four risk groups was significantly different (p < 0.0001); the model stratified survival well with a Harrell's concordance statistic of 0.62 (95% confidence interval: 0.57–0.66) at 36 months. The group with the longest survival (median, 82.5 months) had: no weight loss, hemoglobin > 153 g/L and serum albumin > 43 g/L at time of referral to the surgical center.Conclusions
Using routinely available clinical variables, the CART model was able to stratify surgical patients into risk groups with statistically different survival characteristics with fair to good performance. Presence of weight loss, anemia, and low albumin should confer caution when considering surgical therapy for MPM. 相似文献16.
Verônica M. Couto Maria J. Prieto Daniela E. Igartúa Daniela A. Feas Lígia N.M. Ribeiro Camila M.G. Silva Simone R. Castro Viviane A. Guilherme Darlene D. Dantzger Daisy Machado Silvia del V. Alonso Eneida de Paula 《Journal of pharmaceutical sciences》2018,107(9):2411-2419
Administration of local anesthetics is one of the most effective pain control techniques for postoperative analgesia. However, anesthetic agents easily diffuse into the injection site, limiting the time of anesthesia. One approach to prolong analgesia is to entrap local anesthetic agents in nanostructured carriers (e.g., liposomes). Here, we report that using an ammonium sulphate gradient was the best strategy to improve the encapsulation (62.6%) of dibucaine (DBC) into liposomes. Light scattering and nanotracking analyses were used to characterize vesicle properties, such as, size, polydispersity, zeta potentials, and number. In vitro kinetic experiments revealed the sustained release of DBC (50% in 7 h) from the liposomes. In addition, in vitro (3T3 cells in culture) and in vivo (zebrafish) toxicity assays revealed that ionic-gradient liposomes were able to reduce DBC cyto/cardiotoxicity and morphological changes in zebrafish larvae. Moreover, the anesthesia time attained after infiltrative administration in mice was longer with encapsulated DBC (27 h) than that with free DBC (11 h), at 320 μM (0.012%), confirming it as a promising long-acting liposome formulation for parenteral drug administration of DBC. 相似文献
17.
Michelle Z. Dion Danielle Leiske Vikas K. Sharma Christina L. Zuch de Zafra Cleo M. Salisbury 《Pharmaceutical research》2018,35(11):222
Purpose
Biotherapeutics can be susceptible to oxidation during manufacturing and storage. Free L-methionine is known to protect methionine residues in proteins from oxidation. Similarly, free tryptophan and other indole derivatives have been shown to protect tryptophan residues from oxidation. N-acetyl-DL-tryptophan was previously identified as a potentially superior antioxidant to tryptophan as it has a lower oxidation potential and produces less peroxide upon light exposure. This study sought to confirm the antioxidant efficacy and safety of N-acetyl-DL-tryptophan and L-methionine as formulation components for biotherapeutic drugs.Methods
Antibodies were subjected to AAPH and light exposure in the presence of N-acetyl-DL-tryptophan and L-methionine. Oxidation in relevant CDR and Fc residues was quantified by peptide map. In silico, in vitro, and in vivo studies were performed to evaluate the safety of N-acetyl-DL-tryptophan and L-methionine.Results
Peptide mapping demonstrated that N-acetyl-DL-tryptophan was effective at protecting tryptophans from AAPH stress, and that the combination of N-acetyl-DL-tryptophan and L-methionine protected both tryptophan and methionine from AAPH stress. The safety assessment suggested an acceptable safety profile for both excipients.Conclusions
N-acetyl-tryptophan and L-methionine effectively reduce the oxidation of susceptible tryptophan and methionine residues in antibodies and are safe for use in parenteral biotherapeutic formulations.18.
Infrequent isolation of extensively drug-resistant (XDR) Klebsiella pneumoniae resistant to colistin in Spain 总被引:1,自引:0,他引:1
19.
Hille T. de Vries Takashi Nakamae Kenji Fukui Damiaan Denys Jin Narumoto 《European neuropsychopharmacology》2018,28(6):780-781
Background
A large number of studies have reported the high prevalence of problematic internet use (PIU) among adolescents and students (13-50%)1, and PIU has been associated with many psychiatric symptoms2. In contrast, only a few studies have investigated its prevalence among the adult population. To the best of our knowledge, there have been no studies investigating the prevalence and comorbidity of PIU in a psychiatric population although psychiatric symptoms might either induce PIU in patients with psychiatric illnesses, or PIU might induce or aggravate psychiatric symptoms. The aims of this study are to investigate the prevalence of PIU and psychiatric co-morbidity among adult psychiatric patients.Methods
Three hundred thirty-three adult psychiatric patients with internet access were recruited at the outpatient clinic of psychiatry at the University Hospital, Kyoto Prefectural University of Medicine over a three-month period. Two hundred thirty-one of them completed the survey (response rate: 69.4%; Male/Female/Transgender: 90/139/2; mean age = 42.2). We divided participants into “normal internet users” and “problematic internet users” using a combination of Young’s Internet Addiction Test (IAT) and the Compulsive Internet Use Scale (CIUS), using established cut-off values. Demographic data and comorbid psychiatric symptoms were compared between the two groups, using self-rating scales measuring insomnia (Athens Insomnia Scale, AIS), depression (Beck Depression Inventory, BDI), anxiety (State-trait Anxiety Inventory, STAI), attention deficit hyperactivity disorder (ADHD) (Adult ADHD Self-report Scale, ASRS), autism (Autism Spectrum Quotient, AQ), obsessive-compulsive disorder (OCD) (Obsessive-Compulsive Inventory, OCI), social anxiety disorder (SAD) (Liebowitz Social Anxiety Scale, LSAS), alcohol abuse, and impulsivity (Barratt Impulsive Scale, BIS).Results
Of our 231 respondents, 58 (25.1%) were defined as problematic internet users, as they scored high on either the IAT (40 or more) or CIUS (21 or more). The age of problematic internet users was significantly lower than that of normal internet users (35.9 vs 43.6, p<0.001, Mann-Whitney U test). The problematic internet users scored significantly higher on scales measuring sleep problems (AIS, 8.8 for problematic internet users vs 6.3 for normal internet users, p<0.001), depression (BDI, 27.4 vs 18.3, p<0.001), trait anxiety (STAI, 61.8 vs 53.9, p<0.001), ADHD (ASRS, part A 3.1 vs 1.8 and part B 3.5 vs 1.8, p<0.001), autism (AQ, 25.9 vs 21.6, p<0.001), OCD (OCI, 63.2 vs 36.3, p<0.001), SAD (LSAS, 71.4 vs 54.0, p<0.001), and impulsivity (BIS, 67.4 vs 63.5, p=0.004).Conclusions
The prevalence of PIU among adult psychiatric patients is relatively high (25%). As previous studies reported in the general population, PIU among adult psychiatric patients was associated with lower age and higher psychiatric comorbidity. Longitudinal research is needed to determine any causal relations between problematic internet use and psychopathological illnesses. 相似文献20.
Francesca Waddington Catharina Hartman Yvette de Bruijn Martijn Lappenschaar Anoek Oerlemans Jan Buitelaar Barbara Franke Nanda Rommelse 《European neuropsychopharmacology》2018,28(9):994-1005
Autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) are frequently comorbid disorders. Emotion recognition problems are considered an important familial deficit in ASD, but this is unknown in ADHD. Very few studies have directly compared emotion recognition performance of youth with ASD and/or ADHD and of their unaffected siblings across age to quantify the contribution of emotion recognition problems to the ADHD phenotype. We therefore devised a study of 64 ASD+ADHD participants, 89 ASD-only participants, 111 ADHD-only participants, 122 unaffected ASD(+ADHD) siblings, 69 unaffected ADHD-only siblings and 220 controls aged 7–18 years, who had completed two tasks assessing auditory and visual emotion recognition. Factor analysis was used to detect underlying dimensions of emotion recognition capacity. Linear mixed models were used to compare performance across groups and to assess age effects. The factor-analysis revealed four factors separating speed and accuracy regarding visual and auditory emotion recognition. ASD+ADHD, ASD-only, and ADHD-only participants all performed worse than controls. ASD+ADHD, ASD-only, and ADHD-only participants did not differ in the severity of their emotion recognition problems. Both unaffected sibling groups performed intermediate between patients and controls. For ASD+ADHD and ADHD-only participants, group differences were more marked in adolescence than childhood, whereas in ASD participants this was not observed. We conclude that emotion recognition problems are a familial deficit in ADHD to a similar extent as in ASD. Emotion recognition problems specifically - and social cognition problems more generally - should be assessed in clinical practice for ADHD. 相似文献