全文获取类型
收费全文 | 3698篇 |
免费 | 268篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 144篇 |
妇产科学 | 92篇 |
基础医学 | 546篇 |
口腔科学 | 73篇 |
临床医学 | 419篇 |
内科学 | 842篇 |
皮肤病学 | 77篇 |
神经病学 | 345篇 |
特种医学 | 107篇 |
外科学 | 377篇 |
综合类 | 15篇 |
一般理论 | 3篇 |
预防医学 | 294篇 |
眼科学 | 53篇 |
药学 | 267篇 |
中国医学 | 8篇 |
肿瘤学 | 297篇 |
出版年
2023年 | 38篇 |
2022年 | 58篇 |
2021年 | 129篇 |
2020年 | 81篇 |
2019年 | 99篇 |
2018年 | 96篇 |
2017年 | 69篇 |
2016年 | 110篇 |
2015年 | 108篇 |
2014年 | 124篇 |
2013年 | 182篇 |
2012年 | 251篇 |
2011年 | 255篇 |
2010年 | 141篇 |
2009年 | 107篇 |
2008年 | 207篇 |
2007年 | 220篇 |
2006年 | 205篇 |
2005年 | 195篇 |
2004年 | 169篇 |
2003年 | 153篇 |
2002年 | 161篇 |
2001年 | 69篇 |
2000年 | 53篇 |
1999年 | 61篇 |
1998年 | 40篇 |
1997年 | 28篇 |
1996年 | 17篇 |
1995年 | 16篇 |
1994年 | 23篇 |
1992年 | 38篇 |
1991年 | 32篇 |
1990年 | 29篇 |
1989年 | 25篇 |
1988年 | 29篇 |
1987年 | 19篇 |
1986年 | 24篇 |
1985年 | 19篇 |
1984年 | 21篇 |
1983年 | 20篇 |
1982年 | 15篇 |
1981年 | 10篇 |
1979年 | 18篇 |
1978年 | 12篇 |
1977年 | 11篇 |
1976年 | 10篇 |
1973年 | 10篇 |
1972年 | 11篇 |
1969年 | 9篇 |
1966年 | 10篇 |
排序方式: 共有3985条查询结果,搜索用时 31 毫秒
41.
Matte U Yogalingam G Brooks D Leistner S Schwartz I Lima L Norato DY Brum JM Beesley C Winchester B Giugliani R Hopwood JJ 《Molecular genetics and metabolism》2003,78(1):37-43
In this study we have investigated a group of 29 Brazilian patients, who had been diagnosed with the lysosomal storage disorder, Mucopolysaccharidosis type I (MPS-I). MPS I is caused by a deficiency in the lysosomal hydrolase, alpha-L-iduronidase. Ninety percent of the MPS I patients in this study were genotyped and revealed 10 recurrent and thirteen novel IDUA gene mutations. Eight of these new mutations and three common mutations W402X, P533R, and R383H were individually expressed in CHO-K1 cells and analyzed for alpha-L-iduronidase protein and enzyme activity. A correlation was observed between the MPS I patient clinical phenotype and the associated mutant alpha-L-iduronidase protein/enzyme activity expressed in CHO-K1 cells. This was the first time that Brazilian MPS I patients had been thoroughly analyzed and highlighted the difficulties of mutation screening and clinical phenotype assessment in populations with high numbers of unique mutations. 相似文献
42.
Suppressive effect of leflunomide metabolite (A77 1726) on metalloproteinase production in IL-1beta stimulated rheumatoid synovial fibroblasts 总被引:2,自引:0,他引:2
Migita K Miyashita T Ishibashi H Maeda Y Nakamura M Yatsuhashi H Ida H Kawakami A Aoyagi T Kawabe Y Eguchi K 《Clinical and experimental immunology》2004,137(3):612-616
Leflunomide, an isoxazol derivative structurally unrelated to other immunomodulatory drugs, has proven to be efficacious in the treatment of rheumatoid arthritis (RA). This study was conducted to elucidate the mechanism by which leflunomide mediated antirheumatic effects. We investigated the effects of A77 1726, leflunomide's active metabolite, on mitogen-activated protein kinase (MAPK) activation in IL-1beta-stimulated rheumatoid synovial fibroblasts. The effects of A77 1726 on the secretion of matrix metalloproteinases (MMPs) from rheumatoid synovial fibroblasts were also examined. A77 1726 partially suppressed IL-1beta-induced ERK1/2 and p38 kinase activation. In contrast, A77 1726 efficiently suppressed IL-1beta-stimulated JNK1/2 kinase activation. Although no suppressive effect was demonstrated on MMP-2, A77 1726 markedly inhibited MMP-1, 3, and 13 secretions from IL-1beta-stimulated rheumatoid synovial fibroblasts. Tissue inhibitor of metalloproteinases-1 (TIMP-1) was constitutively produced from rheumatoid synovial fibroblasts and the suppressive effects of A77 1726 on TIMP-1 production were minimal. Our results suggest that the suppression of the MAPK signalling pathway and MMP synthesis in rheumatoid synovial fibroblasts is a possible mechanism for the inhibitory activity of leflunomide against rheumatoid arthritis. 相似文献
43.
Aanesen Fiona Øiestad Britt Elin Grotle Margreth Løchting Ida Solli Rune Sowden Gail Wynne-Jones Gwenllian Storheim Kjersti Eik Hedda 《Journal of occupational rehabilitation》2022,32(2):306-318
Journal of Occupational Rehabilitation - Purpose To perform a process evaluation of a stratified vocational advice intervention (SVAI), delivered by physiotherapists in primary care, for people on... 相似文献
44.
BackgroundPerson‐centred care implies a change in interaction between care professionals and patients where patients are not passive recipients but co‐producers of care. The interactional practices of person‐centred care remain largely unexplored.ObjectiveThis study focuses on the analysis of disagreements, which are described as an important part in the co‐production of knowledge in interaction.DesignA qualitative exploratory study using conversation analysis.Setting and participantsData were collected from a nurse‐led person‐centred intervention in a hospital outpatient setting. Interactions between adult patients with irritable bowel syndrome (n = 17) and a registered nurse were audio‐recorded. COREQ guidelines were applied.ResultsDisagreements were found after demonstration of the nurse''s or patients’ respective professional or personal knowledge. Disagreements were also evident when deciding on strategies for self‐management. Although negotiations between opposing views of the nurse and patient were seen as important, the patient generally claimed final authority both in knowing how IBS is perceived and in the right to choose self‐management strategies. The nurse generally oriented towards patient authority, but instances of demonstration of nurse authority despite patient resistance were also found.Discussion and conclusionsThis study provides information on how co‐production of knowledge and decisions occur in the context of a person‐centred care intervention. Negotiations between nurse and patient views require a flexible approach to communication, adapting interaction to each context while bearing in mind the patients having the final authority. To facilitate co‐production, the patient''s role and responsibilities in interaction should be explicitly stated. 相似文献
45.
Ida Micaily MD Hannah Hackbart Meghan Butryn PhD Maysa M. Abu-Khalaf MD 《The breast journal》2021,27(7):603-607
Obesity is a modifiable risk factor in breast cancer patients and is predictive of disease outcomes in early-onset breast cancer survivors. The purpose of this review is to summarize the current evidence in the association between early-onset breast cancer and obesity, specifically in African-American women. Reviewing the molecular mechanisms and social determinants of disease in this population can provide a foundation for future interventions in prevention, detection, and treatment aiming at improving outcomes for young breast cancer patients. 相似文献
46.
John M. Søfteland Gustav Friman Bengt von Zur-Mühlen Bo-Göran Ericzon Carin Wallquist Kristjan Karason Vanda Friman Jan Ekelund Marie Felldin Jesper Magnusson Ida Haugen Löfman Andreas Schult Emily de Coursey Susannah Leach Hanna Jacobsson Jan-Åke Liljeqvist Ali R. Biglarnia Per Lindnér Mihai Oltean 《American journal of transplantation》2021,21(8):2762-2773
Solid organ transplant (SOT) recipients run a high risk for adverse outcomes from COVID-19, with reported mortality around 19%. We retrospectively reviewed all known Swedish SOT recipients with RT-PCR confirmed COVID-19 between March 1 and November 20, 2020 and analyzed patient characteristics, management, and outcome. We identified 230 patients with a median age of 54.0 years (13.2), who were predominantly male (64%). Most patients were hospitalized (64%), but 36% remained outpatients. Age >50 and male sex were among predictors of transition from outpatient to inpatient status. National early warning Score 2 (NEWS2) at presentation was higher in non-survivors. Thirty-day all-cause mortality was 9.6% (15.0% for inpatients), increased with age and BMI, and was higher in men. Renal function decreased during COVID-19 but recovered in most patients. SARS-CoV-2 antibodies were identified in 78% of patients at 1–2 months post-infection. Nucleocapsid-specific antibodies decreased to 38% after 6–7 months, while spike-specific antibody responses were more durable. Seroprevalence in 559 asymptomatic patients was 1.4%. Many patients can be managed on an outpatient basis aided by risk stratification with age, sex, and NEWS2 score. Factors associated with adverse outcomes include older age, male sex, greater BMI, and a higher NEWS2 score. 相似文献
47.
ObjectiveThis study aimed to compare longitudinal changes in ovarian reserve markers after cesarean section (CS) with and without bilateral salpingectomy (BS).Study designWe prospectively enrolled women >35 weeks’ gestation scheduled for CS alone or CS + BS and obtained blood samples for anti-Müllerian hormone prior to surgery and at 3 and 6 months after surgery. At the 3-month visit, we similarly performed transvaginal ultrasound for antral follicle count.ResultsWe enrolled 50 women; 30 underwent CS only and 20 underwent CS + BS. Although anti-Müllerian hormone level increased over 6 months of follow-up in both groups, no clinically important differences in the geometric mean (interquartile range) (ng/mL) were observed at any timepoint (baseline [0.69 {0.36?1.21} {CS only} vs 0.49 {0.32?2.10} {CS + BS}, p = 0.64]; 3 months [1.35 {0.58?3.13} vs 1.45 {1.04?2.25}, p = 0.79]; and 6 months [1.74 {0.93?4.45} vs 2.60 {1.41?5.10}, p =0.27]). Similarly, we detected no difference in antral follicle count.ConclusionBS at the time of CS does not have a negative impact on ovarian reserve 6 months after surgery.ImplicationWhile our results provide reassuring data that bilateral salpingectomy for permanent contraception at the time of cesarean section does not impact ovarian reserve, longer adequately powered studies are needed. 相似文献
48.
Houghton Stephen Marais Ida Hunter Simon C. Carroll Annemaree Lawrence David Tan Carol 《Quality of life research》2021,30(2):589-601
Quality of Life Research - The psychometric properties of the Perth A-loneness Scale (PALs) have been extensively validated using classical test theory, but to date no studies have applied a Rasch... 相似文献
49.
Two human liver UDP-glucuronosyltransferase cDNA clones, HLUG25 and UDPGTh2 were previously shown to encode isozymes active in the glucuronidation of hyodeoxycholic acid (HDCA) and certain estrogen derivatives (e.g., estriol and 3,4-catechol estrogens), respectively. In this study we have found that the UDPGTh-2-encoded isoform (UDPGTh2) and HLUG25-encoded isoform (UDPGTh1) have parallel aglycone specificities. When expressed in COS 1 cells, each isoform metabolized three types of dihydroxy- or trihydroxy-substituted ring structures, including the 3,4-catechol estrogen (4-hydroxyestrone), estriol, 17-epiestriol, and HDCA, but the UDPGTh2 isozyme was 100-fold more efficient than UDPGTh1. UDPGTh1 and UDPGTh2 were 86% identical overall (76 differences out of 528 amino acids), including 55 differences in the first 300 amino acids of the amino terminus, a domain which conferred the substrate specificity. The data indicated that a high level of conservation in the amino terminus was not required for the preservation of substrate selectivity. Analysis of glucuronidation activity encoded by UDPGTh1/UDPGTh2 chimeric cDNA constructed at their common restriction sites,Sac 1 (codon 297),Nco 1 (codon 385), andHha 1 (codon 469), showed that nine amino acids between residues 385 and 469 were important for catalytic efficiency, suggesting that this region represented a domain which was critical for the catalysis but distinct from that responsible for aglycone selection. These data indicate, that UDPGTh2 is a primary isoform responsible for the detoxification of the bile salt intermediate as well as the active estrogen intermediates. 相似文献
50.
The human liver cDNA clone UDPGTh2, encoding a liver UDP-glucuronosyltransferase (UDPGT) was isolated from a λ gt 11 cDNA
library by hybridization to mouse transferase cDNA clone, UDPGTm1. UDPGTh2 encoded a 529 amino acid protein with an amino
terminus membrane-insertion signal peptide and a carboxyl terminus membrane-spanning region. There were three potential asparagine-linked
glycosylation sites at residues 67, 68, and 315. In order to obtain UDPGTh2 protein encoded from cloned human liver UDP-glucuronosyltransferase
cDNA, the clone was inserted into the pSVL vector (pUDPGTh2) and expressed in COS 1 cells. The presence of a transferase with
Mr≈52,000 in transfected cells cultured in the presence of [35S]methionine was shown by immunocomplexed products with goat antimouse transferase IgG and protein A-Sepharose and analysis
by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. The expressed UDPGT was a glycoprotein as
indicated by electrophoretic mobility shift in Mr≈3,000–4,000 when expressed in the presence of tunicamycin. The extent of
glycosylation was difficult to assess, although one could assume that glycosyl structures incorporated at the level of endoplasmic
reticulum were always the core oligosaccharides. Thus, it is likely that at least two moieties inserted can account for the
shift of Mr≈3,000–4,000. This study demonstrates the cDNA and deduced amino acid sequence of human liver UDP-glucuronosyltransferase
cDNA, UDPGTh2. 相似文献