全文获取类型
收费全文 | 74482篇 |
免费 | 40688篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 1474篇 |
儿科学 | 4170篇 |
妇产科学 | 492篇 |
基础医学 | 15177篇 |
口腔科学 | 5027篇 |
临床医学 | 12051篇 |
内科学 | 22365篇 |
皮肤病学 | 7414篇 |
神经病学 | 13057篇 |
特种医学 | 2105篇 |
外科学 | 13403篇 |
综合类 | 2篇 |
一般理论 | 21篇 |
预防医学 | 3972篇 |
眼科学 | 1200篇 |
药学 | 5368篇 |
中国医学 | 1008篇 |
肿瘤学 | 6865篇 |
出版年
2024年 | 1篇 |
2023年 | 10篇 |
2022年 | 17篇 |
2021年 | 1208篇 |
2020年 | 5008篇 |
2019年 | 10768篇 |
2018年 | 10009篇 |
2017年 | 11392篇 |
2016年 | 12030篇 |
2015年 | 11863篇 |
2014年 | 11728篇 |
2013年 | 12174篇 |
2012年 | 3876篇 |
2011年 | 3793篇 |
2010年 | 8783篇 |
2009年 | 5155篇 |
2008年 | 1851篇 |
2007年 | 696篇 |
2006年 | 749篇 |
2005年 | 533篇 |
2004年 | 556篇 |
2003年 | 572篇 |
2002年 | 665篇 |
2001年 | 742篇 |
2000年 | 665篇 |
1999年 | 239篇 |
1998年 | 18篇 |
1997年 | 10篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 11篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1978年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
181.
182.
183.
R. Kazi V. Prasad R. Venkitaraman C.M. Nutting P. Clarke P. Rhys‐Evans K.J. Harrington 《Clinical otolaryngology》2006,31(6):525-530
Objective: To determine the effects of a total laryngectomy on the swallow and subsequent quality of life in head and neck cancer patients. Design: Cross‐sectional single centre cohort study. Setting: Head and Neck Oncology Unit, Tertiary Referral Unit. Patients: Sixty‐two patients who underwent total laryngectomy at our centre participated in the study. Methods: Subjects were stratified by age, sex, tumour stage, other procedures such as myotomy and nerve re‐implantation. Pharyngectomy, glossectomy, flap reconstruction, neck dissection and previous radio‐ and chemotherapy were also assessed to see if they affected swallow and subsequent quality of life. Main outcome was measured using the MD Anderson Dysphagia Inventory questionnaire. Results: Responses were received from 46 males and 16 females (response rate of 80.5%) with a mean age of 64.7 years (SD 9.4). Median follow‐up in patients was 90 months (range 1–276). The mean MD Anderson Dysphagia Inventory total score in our series of patients was 77.7 (SD 16.6). MD Anderson Dysphagia Inventory global score was 79.4 (SD 22.6), Emotional score was 77.7 (SD 17.8), Functional score 81.3 (SD 15.9) and Physical score was 74.1(SD 18). Statistically significant differences were seen between the emotional scores of glossectomised and non‐glossectomised patients (Mann Whitney, P = 0.04). No significant correlation was seen between the subscale scores and the remaining treatment variables such as age, gender, site, tumour stage, myotomy, nerve implantation, radiotherapy, reconstruction and major complications. Conclusion: This questionnaire study is the largest of its type to assess the swallow of patients who have undergone laryngectomy at a single centre. The overall result confirmed that most patients had a subjectively good swallow. Only glossectomy and the method of PE segment closure were shown to significantly affect swallowing outcomes following surgery. We recommend further work especially prospective studies pre and post surgery using this or similarly validated instruments to fully assess swallow in the laryngectomy population. 相似文献
184.
R. Tazi‐Ahnini A. Cox A. J. G. McDonagh M. J. H. Nicklin F. S. Di Giovine J. M. Timms A. G. Messenger P. Dimitropoulou G. W. Duff M. J. Cork 《International journal of immunogenetics》2002,29(1):25-30
Alopecia areata is an inflammatory hair loss disease with a major genetic component. The presence of focal inflammatory lesions with perifollicular T‐cell infiltrates reflects the importance of local cytokine production in the pathogenesis. In addition to its fundamental pro‐inflammatory role, the interleukin‐1 (IL‐1) system has major effects on hair growth regulation in vitro, with the inhibitory actions of IL‐1α and IL‐1β being opposed by the receptor antagonist IL‐1ra. The novel interleukin‐1 like molecule 1 (IL‐1L1) which has greatest gene sequence homology with IL1RN, the gene encoding IL‐1ra, is another potential IL‐1 antagonist. In view of previous studies suggesting a significant role for IL1RN polymorphisms in the pathogenesis of autoimmune/inflammatory disease, we have analysed polymorphisms of IL‐1ra (IL1RN+2018) and its homologue IL‐1L1 (IL1L1+4734) in a case–control association study on 165 patients and a large number of matched controls. Homozygosity for the rare allele of IL1RN (IL1RN*2) was significantly associated with alopecia areata [odds ratio (OR) = 1.89, 95% CI (1.09, 3.28); P = 0.02], confirming our previous findings of significant association with the IL1RN variable number tandem repeat (VNTR). The results also revealed a novel association involving a polymorphism of the interleukin‐1 receptor antagonist homologue IL1L1 at position + 4734, IL1RN+2018, and alopecia areata. The effect of a genotype combining three copies of the rare alleles at the IL1RN and IL1L1 loci conferred a more than additive increase in the risk of disease compared to IL1RN+2018 or IL1L1+4734 alone [OR 3.37 (1.60, 7.06); P = 0.002], suggesting possible synergy between the IL1RN and IL1L1 genes. This effect was stronger in patients with severe disease (alopecia totalis/universalis) [OR 4.62 (1.87, 11.40), P = 0.0022], and in those with early age at onset (< 20 years) [OR = 6.38 (2.64, 15.42), P = 0.0002]. Our results suggest that these polymorphisms within IL1RN and IL1L1 themselves or a gene in linkage disequilibrium with IL1RN and IL1L1 predispose to the more severe forms of alopecia areata. 相似文献
185.
186.
Patrick Terheyden Jürgen C. Becker Christa Lurz George J. Kahaly Eva‐B. Brcker 《Journal der Deutschen Dermatologischen Gesellschaft》2003,1(1):30-35
Background: Scleromyxoedema is a rare disease of unknown aetiology that is characterized by deposition of mucin and sclerotic induration of the skin; it is associated with paraproteinaemia. Patients suffer from progressive disability due to immobilization and cosmetic disfigurement. Treatment of scleromyxoedema is a therapeutic challenge. The antimalarial hydroxychloroquine has a rapid and reliable effect in reticular erythematous mucinosis. Patients and methods: Four consecutive patients (two women, two men; median age: 50 years) with scleromyxoedema, three of them with IgG λ paraprotein, were treated with hydroxychloroquine. Treatment was initiated with 600 mg p. o. for 10 days, followed by 400 mg for at least 4 weeks, and 200 mg thereafter. Results: Complete remission of skin manifestations was achieved in one patient, whereas three patients achieved a partial remission of 61+, 5 and 25 months' duration. Notably, three patients felt increased mobility and reduced firmness of skin during the first week of treatment, which was reflected in a rapid reduction in dermal thickness. In one patient, dysphagia was reverted as evidenced by normalization of oesophageal clearance. Paraproteinaemia was not influenced at all. Side effects included one case of electroretinogram abnormalities after 19 months of therapy and one case of leucopenia after 3 months. Conclusion: Hydroxychloroquine is an effective form of therapy for scleromyxoedema, leading to rapid and prolonged alleviation of symptoms. 相似文献
187.
Depression and anxiety disorders associated with headache frequency. The Nord‐Trøndelag Health Study
J.‐A. Zwart G. Dyb K. Hagen K. J.
degrd A. A. Dahl G. Bovim L. J. Stovner 《European journal of neurology》2003,10(2):147-152
The aim of this large cross‐sectional population‐based study was to examine the association between migraine, non‐migrainous headache and headache frequency with depression, and anxiety disorders. From 1995 to 1997, all 92 566 inhabitants aged 20 years and above in Nord‐Trøndelag County in Norway were invited to participate in the Nord‐Trøndelag Health Study (‘Helseundersøkelsen i Nord‐Trøndelag’ = HUNT‐2). A total of 64 560 participated, whereof 51 383 subjects (80%) completed a headache questionnaire that was included. Of these 51 383 individuals, 47 257 (92%) completed the depression subscale items and 43 478 (85%), the anxiety subscale items of the Hospital Anxiety and Depression Scale (HADS). Associations were assessed in multivariate analyses, estimating prevalence odds ratios (OR) with 95% confidence intervals (CI). Depression and anxiety disorders as measured by HADS, were significantly associated with migraine (OR = 2.7, 95% CI 2.3–3.2; OR = 3.2, 95% CI 2.8–3.6) and non‐migrainous headache (OR = 2.2, 95% CI 2.0–2.5; OR = 2.7, 95% CI 2.4–3.0) when compared with headache‐free individuals. The association was stronger for anxiety disorders than for depression. The ORs for depression and anxiety disorders amongst both migraine and non‐migrainous sufferers increased with increasing headache frequency. Depression and anxiety disorders are associated with both migraine and non‐migrainous headache, and this association seems more dependent on headache frequency than diagnostic category. 相似文献
188.
Z.‐H. Liu J. Lin D. Pan W. Chen H. Tao A. Xu 《International journal of immunogenetics》2002,29(3):259-261
A sequencing‐based typing of the HLA‐DPB1 gene was carried out in 51 unrelated healthy individuals from the Yunnan Pumi ethnic minority. A total of 18 DPB1 alleles, in which DPB1*0501 (52.0%) and DPB1*0402 (15.7%) greatly predominated, were found, of which alleles DPB1*20011, 2201, 3601, 3701, 3801, 4901, 5001 and 8001 were recorded for the first time in the Chinese population. This may be because the typing methods used in previous genotyping of Chinese populations were of lower sensitivity than that used in our study. A dendrogram constructed by the maximum likelihood method showed that the Pumi ethnic minority belongs to the Asian/Australasian cluster and has the closest relationship to Trobriander, implying an unusual relationship between Australasian and South China populations. However, the Yi ethnic minority, which also comes from the ancient Qiang, did not show a very close relationship with the Pumi. This is probably because the Pumi were historically assimilated by local south‐west China populations. 相似文献
189.
Valentina Coia Barbara Sansonetti Giorgio Paoli Sergio Tofanelli Gabriella Spedini Giovanni Destro‐Bisol 《American journal of human biology》2002,14(1):9-14
Ten protein coding loci (6‐PGD, A1‐AT, ACP1, CaII, ESD, GC, GPX1, Hbβ, PGM1, and TF) were analyzed in the Mbenzele Pygmies from the Central African Republic. The frequency data were used to calculate the genetic distances between Mbenzele Pygmies and other African groups. In the principal coordinate plot of FST genetic distances, the Mbenzele cluster together with other Pygmies of the western cluster, the Biaka from C.A.R., Gielli from Cameroon, and Babinga from Congo. By contrast, they are considerably distanced from other Pygmy groups of the eastern cluster (Twa from Rwanda, Mbuti from Zaire). Genetic distances obtained using protein loci were compared with those based on microsatellite loci. The two distance matrices are insignificantly correlated (r = 0.268; one tail probability = 0.332), and the main difference is in the higher genetic affinity between the Mbenzele and Biaka Pygmies observed at the protein level. Although reasons underlying the discrepancy between inter‐populational variation at protein and DNA loci are not established with certainty, the comparison suggests that the genetic distance between the Mbenzele and Biaka Pygmies at microsatellite loci could have been shaped by genetic drift. Am. J. Hum. Biol. 14:9–14, 2002.© 2002 Wiley‐Liss, Inc. 相似文献
190.
I. Ibarrola M. L. Sanz† P. M. Gamboa‡ A. Mir§ D. Benahmed§ A. Ferrer¶ M. C. Arilla A. Martínez J. A. Asturias 《Clinical and experimental allergy》2004,34(2):303-309
BACKGROUND: Allergoids are widely used in specific immunotherapy (SIT) for the treatment of IgE-mediated allergic diseases, but all techniques for standardization of conventional allergic extracts may not be appropriate for standardization of a glutaraldehyde (GA)-modified extract because of the unique characteristics of these extracts. OBJECTIVE: To assess an accurate methodology for standardization of chemically modified extracts. METHODS: GA-modified extracts from Parietaria judaica pollen were purified by diafiltration. Biochemical properties were investigated by determination of amino groups, chromatography, and SDS-PAGE. The IgE-binding activity was determined by skin prick test, enzyme allergosorbent test inhibition, basophil activation, and histamine release tests. Peripheral blood mononuclear cells (PBMCs) from P. judaica pollen-allergic subjects were stimulated with either native or allergoid extracts, and proliferation was measured. RESULTS: Biochemical data indicated a high degree of allergen polymerization resulting in extract components higher than 100 kDa. IgE-binding activity, both in vivo and in vitro, was reduced by more than 99.8%. Both allergen and allergoid induced PBMC proliferation and synthesis of blocking IgG antibodies at similar rates. Moreover, no evidence of introduction of new determinants by chemical modification was found. CONCLUSIONS: The preparation of GA-modified extracts by diafiltration is faster and more reliable than previous chromatographic methods. These modified extracts have drastically reduced their allergenicity while maintaining their immunogenicity, and therefore they can be used in safer and shortened schedules of SIT. 相似文献