全文获取类型
收费全文 | 2735篇 |
免费 | 179篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 38篇 |
妇产科学 | 51篇 |
基础医学 | 357篇 |
口腔科学 | 116篇 |
临床医学 | 380篇 |
内科学 | 559篇 |
皮肤病学 | 49篇 |
神经病学 | 172篇 |
特种医学 | 148篇 |
外科学 | 379篇 |
综合类 | 26篇 |
一般理论 | 1篇 |
预防医学 | 159篇 |
眼科学 | 24篇 |
药学 | 257篇 |
中国医学 | 1篇 |
肿瘤学 | 189篇 |
出版年
2023年 | 16篇 |
2022年 | 29篇 |
2021年 | 51篇 |
2020年 | 51篇 |
2019年 | 56篇 |
2018年 | 66篇 |
2017年 | 73篇 |
2016年 | 68篇 |
2015年 | 70篇 |
2014年 | 87篇 |
2013年 | 117篇 |
2012年 | 155篇 |
2011年 | 201篇 |
2010年 | 98篇 |
2009年 | 94篇 |
2008年 | 139篇 |
2007年 | 169篇 |
2006年 | 134篇 |
2005年 | 139篇 |
2004年 | 137篇 |
2003年 | 131篇 |
2002年 | 124篇 |
2001年 | 56篇 |
2000年 | 52篇 |
1999年 | 50篇 |
1998年 | 22篇 |
1997年 | 28篇 |
1996年 | 21篇 |
1995年 | 18篇 |
1994年 | 13篇 |
1993年 | 25篇 |
1992年 | 17篇 |
1991年 | 23篇 |
1990年 | 29篇 |
1989年 | 16篇 |
1988年 | 16篇 |
1987年 | 22篇 |
1986年 | 20篇 |
1985年 | 23篇 |
1984年 | 14篇 |
1983年 | 23篇 |
1982年 | 20篇 |
1980年 | 11篇 |
1979年 | 22篇 |
1978年 | 12篇 |
1977年 | 11篇 |
1976年 | 13篇 |
1975年 | 15篇 |
1974年 | 9篇 |
1966年 | 10篇 |
排序方式: 共有2930条查询结果,搜索用时 15 毫秒
11.
Niels Fisker Court Pedersen Marianne Lange Nga Thien Tich Nguyen Kim Thien Tich Nguyen J?rgen Georgsen Peer Brehm Christensen 《Journal of clinical virology》2004,31(1):46-52
BACKGROUND: Denmark has a low incidence of acute hepatitis B (HBV) infections but the impact of an increasing number of immigrants with chronic HBV infection on HBV transmission is unknown. OBJECTIVES: To characterise individuals with chronic and acute HBV infection in a defined region and to examine the importance of different risk groups for the current HBV transmission. METHODS: During 2000-2001 all consecutive HBV infected individuals routinely diagnosed through the regional HBV serology laboratory in the County of Funen were classified according to ethnicity, presumed route of transmission and stage of infection based on clinical data mainly supplied by the requesting physician. HBV DNA was sequenced and subjected to phylogenetic analysis. RESULTS: Of 309 identified cases, 91 (29%) were classified as acute infection. HBV DNA sequencing was possible in 54 (59%) of these cases. Phylogenetic analysis showed that HBV isolated from injecting drug users (IDUs) was identical or closely related. Among acute cases acquired in Denmark 89% (74/83) were seen in IDUs (65) or in individuals presumably exposed to IDUs (nine) and phylogenetic analysis corroborated the assumption of IDU related transmission in every case with available sequence data. Among 83 ethnic Danes who acquired their HBV infection in Denmark, no new cases of transmission from immigrants were detected. CONCLUSION: Injecting drug use was the single most important factor for hepatitis B transmission in Denmark. The current Danish vaccination strategy is unable to protect IDUs from HBV infection and IDUs pose a greater risk of HBV transmission to the general population than immigrants. 相似文献
12.
We investigate the co-occurrence of domain families in eukaryotic proteins to predict protein cellular localization. Approximately half (300) of SMART domains form a "small-world network", linked by no more than seven degrees of separation. Projection of the domains onto two-dimensional space reveals three clusters that correspond to cellular compartments containing secreted, cytoplasmic, and nuclear proteins. The projection method takes into account the existence of "bridging" domains, that is, instances where two domains might not occur with each other but frequently co-occur with a third domain; in such circumstances the domains are neighbors in the projection. While the majority of domains are specific to a compartment ("locale"), and hence may be used to localize any protein that contains such a domain, a small subset of domains either are present in multiple locales or occur in transmembrane proteins. Comparison with previously annotated proteins shows that SMART domain data used with this approach can predict, with 92% accuracy, the localizations of 23% of eukaryotic proteins. The coverage and accuracy will increase with improvements in domain database coverage. This method is complementary to approaches that use amino-acid composition or identify sorting sequences; these methods may be combined to further enhance prediction accuracy. 相似文献
13.
Kleta R Skovby F Christensen E Rosenberg T Gahl WA Anikster Y 《Molecular genetics and metabolism》2002,76(3):201-206
Type III 3-methylglutaconic aciduria (MGA) (MIM 258501) consists of early bilateral optic atrophy, later development of spasticity, extrapyramidal dysfunction and occasionally cognitive deficits, and urinary excretion of 3-methylglutaconic acid and 3-methylglutaric acid. The presence of the disorder in an Iraqi-Jewish genetic isolate led to mapping of the OPA3 gene to chromosome 19q13.2-q13.3, followed by isolation of the gene itself. OPA3 consists of two exons and codes for a peptide of 179 amino acids. Iraqi-Jewish patients with type III MGA are homozygous for a splice site founder mutation in OPA3 (IVS1-1G>C) which abolishes mRNA expression in fibroblasts. Here we report a novel mutation in OPA3 (320-337del) in a Kurdish-Turkish patient with optic atrophy and 3-methylglutaconic and 3-methylglutaric aciduria, previously carrying the diagnosis of type IV MGA. We conclude that type III MGA occurs in patients of non-Iraqi-Jewish ancestry, and should be considered in patients with type IV MGA that have optic atrophy and ataxia. 相似文献
14.
Phenylketonuria (PKU) is caused by deficiency of phenylalanine hydroxylase (PAH) and increased levels of phenylalanine. PAH requires the cofactor BH(4) to function and the rate-limiting step in the synthesis of BH(4) is GTP cyclohydrolase I (GTP-CH). The skin is a potential target tissue for PKU gene therapy. We have previously shown that overexpression of PAH and GTP-CH in primary human keratinocytes leads to high levels of phenylalanine clearance without BH(4) supplementation [Gene Ther. 7 (2000) 1971]. Here, we investigate the capacity of fibroblasts, another cell type from the skin, to metabolize phenylalanine. After retroviral gene transfer of PAH and GTP-CH both normal and PKU patient fibroblasts were able to metabolize phenylalanine, however, in lower amounts compared to genetically modified keratinocytes. Further comparative analyses between keratinocytes and fibroblasts revealed a higher copy number of transgenes in keratinocytes and also a higher metabolic capacity. 相似文献
15.
Eriksen HR Hellesnes B Staff P Ursin H 《International journal of behavioral medicine》2004,11(2):122-125
Subjective health complaints without or with minimal somatic findings (pain, fatigue) are common and frequent reasons for encounter with the general practitioner and for long-term sickness leave and disability. The complaints are often attributed to the stressors of modern life. Is this true? We interviewed 120 Aborigine Mangyans (native population, M age = 33.5 years, 72.5% women) living under primitive conditions in the jungle of Mindoro, an island in the Philippines, and 101 persons living in a small coastal town on the same island (coastal population, M age = 33.8 years, 60.4% women). Both groups had more musculoskeletal complaints, fatigue, mood changes, and gastrointestinal complaints than a representative sample from the Norwegian population (N = 1,243). Our common subjective health complaints, therefore, are not specific for industrialized societies. 相似文献
16.
17.
Peer Arts Jessica Garland Alicia B. Byrne Tristan S.E. Hardy Milena Babic Jinghua Feng Paul Wang Thuong Ha Sarah L. King‐Smith Andreas W. Schreiber April Crawford Nick Manton Lynette Moore Christopher P. Barnett Hamish S. Scott 《American journal of medical genetics. Part A》2020,182(5):1273-1277
Autosomal dominant (de novo) mutations in PBX1 are known to cause congenital abnormalities of the kidney and urinary tract (CAKUT), with or without extra‐renal abnormalities. Using trio exome sequencing, we identified a PBX1 p.(Arg107Trp) mutation in a deceased one‐day‐old neonate presenting with CAKUT, asplenia, and severe bilateral diaphragmatic thinning and eventration. Further investigation by droplet digital PCR revealed that the mutation had occurred post‐zygotically in the father, with different variant allele frequencies of the mosaic PBX1 mutation in blood (10%) and sperm (20%). Interestingly, the father had subclinical hydronephrosis in childhood. With an expected recurrence risk of one in five, chorionic villus sampling and prenatal diagnosis for the PBX1 mutation identified recurrence in a subsequent pregnancy. The family opted to continue the pregnancy and the second affected sibling was stillborn at 35 weeks, presenting with similar severe bilateral diaphragmatic eventration, microsplenia, and complete sex reversal (46, XY female). This study highlights the importance of follow‐up studies for presumed de novo and low‐level mosaic variants and broadens the phenotypic spectrum of developmental abnormalities caused by PBX1 mutations. 相似文献
18.
Kathryn L. Young-Shand Michael J. Dunbar Elise K. Laende Joanna E. Mills Flemming Janie L. Astephen Wilson 《The Journal of arthroplasty》2021,36(7):2473-2479
BackgroundThere are numerous reports of poor satisfaction after total knee arthroplasty (TKA), yet there is little known about when to use evidence-based models of care to improve patient outcomes.ObjectiveThis study aimed to characterize longitudinal changes in patient-reported satisfaction after TKA and to identify factors for early identification of poor satisfaction.MethodsFor a cohort of primary TKA surgeries (n = 86), patient-reported outcomes were captured one week before TKA and 6 weeks, 12 weeks, 6 months, and 1 and 2 years after TKA. “Satisfied” versus “not fully satisfied” patients were defined using a binary response (≥90 vs <90) from a 100-point scale. Wilcoxon signed-rank tests identified changes in satisfaction between follow-up times, and longitudinal analyses examined demographic and questionnaire factors associated with satisfaction.ResultsImprovements in satisfaction occurred within the first 6 months after TKA (P ≤ 0.01). Preoperative patient-reported outcome measures alone were not predictive of satisfaction. Key factors that improved longitudinal satisfaction included higher Oxford Knee Scores (odds ratio (OR) = 2.1, P < .001), general health (EQ-VAS, OR = 1.3, P = .03), and less visual analog scale pain (VAS; OR = 1.7, P < .001). Differences in these factors between satisfied and not fully satisfied patients were identified as early as 6 weeks after surgery.ConclusionVisibly different satisfaction profiles were captured among satisfied and not fully satisfied patient responses, with differences in patient-perceived joint function, general health, and pain severity occurring as early as 6 weeks after surgery. This study provides metrics to support early identification of patients at risk of poor TKA satisfaction, enabling clinicians to apply timely targeted treatment and support interventions, with the aim of improving patient outcomes. 相似文献
19.
20.
We report on a 12-year old boy suffering from malignant epithelioid hemangioendothelioma of the liver, which is a very rare tumor in childhood. The tumor was detected by ultrasound examination at the age of 10 and appeared at that time as a solitary intrahepatic nodular lesion. During the following 2 years multiple nodular lesions developed in both hepatic lobes. There were neither any suspect anamnestic findings nor abnormal clinical or laboratory data. The tumor showed the typical histomorphological, immunohistochemical, and ultrastructural features of this entity, which is usually seen in older patients. We investigated proliferative activity, apoptotic regulation, and expression of VEGF and VEGF-receptor flk-1 by means of immunohistochemical techniques. According to the known slow growth activity of these tumors we found only a few Ki-67 positive tumor cells. We did not detect any apoptotic cells using TUNEL technique. The positive immunoreaction of the tumor cells with antibodies against VEGF and VEGF-receptor flk-1 may indicate the regulation of tumor growth by angiogenetic factors. We present our findings together with a summary of the most important publications of recent years concerning these tumors. 相似文献