全文获取类型
收费全文 | 998篇 |
免费 | 71篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 19篇 |
妇产科学 | 15篇 |
基础医学 | 147篇 |
口腔科学 | 36篇 |
临床医学 | 115篇 |
内科学 | 192篇 |
皮肤病学 | 12篇 |
神经病学 | 70篇 |
特种医学 | 18篇 |
外科学 | 94篇 |
综合类 | 39篇 |
现状与发展 | 1篇 |
预防医学 | 117篇 |
眼科学 | 5篇 |
药学 | 60篇 |
中国医学 | 9篇 |
肿瘤学 | 128篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 26篇 |
2021年 | 27篇 |
2020年 | 26篇 |
2019年 | 32篇 |
2018年 | 22篇 |
2017年 | 9篇 |
2016年 | 27篇 |
2015年 | 22篇 |
2014年 | 26篇 |
2013年 | 63篇 |
2012年 | 76篇 |
2011年 | 82篇 |
2010年 | 44篇 |
2009年 | 47篇 |
2008年 | 77篇 |
2007年 | 56篇 |
2006年 | 69篇 |
2005年 | 72篇 |
2004年 | 45篇 |
2003年 | 32篇 |
2002年 | 35篇 |
2001年 | 25篇 |
2000年 | 17篇 |
1999年 | 9篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 11篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1976年 | 2篇 |
1973年 | 8篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1969年 | 2篇 |
1961年 | 1篇 |
排序方式: 共有1083条查询结果,搜索用时 15 毫秒
1.
神经外科麻醉对体感诱发电位的影响 总被引:1,自引:0,他引:1
目的探讨神经外科手术麻醉对体感诱发电位(SEP)的影响,以期为麻醉和手术处理提供依据。方法随机抽取我科17例全麻手术病人,分成颅内疾病手术组(A组)与脊柱、脊髓疾病手术组(B组),于术前、麻醉(诱导完成)、术始、术中、术毕和术后6个时程连续监测SEP的潜伏期、波幅及波形并记录。结果麻醉后SEP潜伏期延长5.96%,波幅下降24.00%,未出现波形消失的情况。结论麻醉抑制SEP,表现为潜伏期延长和波幅下降,但未出现波形消失的情况。 相似文献
2.
P Knekt A Reunanen A Aromaa M Heli?vaara T Hakulinen M Hakama 《Journal of clinical epidemiology》1988,41(6):519-530
Serum cholesterol concentration was studied for its prediction of cancer in 39,268 men and women aged 15-99 years and initially free from cancer. During a median follow-up of 10 years 1381 cancer cases were diagnosed. Serum cholesterol level was inversely associated with cancer incidence among non-smokers. Age-adjusted relative risks of cancer in quintiles of serum cholesterol were in male non-smokers 1.0, 0.81, 0.73, 0.69, and 0.46 and in female non-smokers 1.0, 0.75, 0.84, 0.78, and 0.70. The associations were not found to be confounded by serum vitamins A or E, serum selenium or several other factors. The association between serum cholesterol level and risk of cancer varied from strongly negative to slightly positive according to subpopulation and site of cancer. The strongest negative associations were found to appear during the first years of follow-up, especially for rapidly developing cancers. Thus the increased occurrence of cancer at low cholesterol levels seems mainly to be due to preclinical cancer. 相似文献
3.
National yearly surveys were carried out between 1985 and 1989 to determine the prevalence of antibodies for human immunodeficiency virus (HIV) in Finnish patients with bleeding disorders. From 192 out of the 214 haemophiliacs (90%) tested, 2 patients were positive for anti-HIV. No seropositivities were found after 1985. Fourteen out of 21 patients (67%) with type III von Willebrand's disease, and 7 out of 8 patients (88%) with factor XIII deficiency were tested with negative results. The low prevalence of anti-HIV (0.94%; 2/213 tested), is mainly due to the self-sufficiency for clotting factors, the low prevalence of HIV in the population, and the use of cryoprecipitate during the critical period. 相似文献
4.
High-efficiency gene transfer to primary T lymphocytes by recombinant adenovirus vectors 总被引:3,自引:0,他引:3
Zhi Chen Matti Ahonen Heli Hmlinen Jeffrey M. Bergelson Veli-Matti Khri Riitta Lahesmaa 《Journal of immunological methods》2002,260(1-2):79-89
Recombinant, replication-deficient adenoviruses are efficient vectors for gene transfer to a wide range of cell types, with the exception of T lymphocytes. Here, we show that primary T lymphocytes from peripheral blood, cord blood, and the Jurkat T cell line are efficiently transduced by recombinant adenovirus. Nearly 100% infection efficiency of primary T cells is obtained with high multiplicity of infection (MOI) (5000) of recombinant adenovirus coding for lacZ. Similar infection efficiency by adenovirus-mediated gene transfer was obtained at lower MOI (3000) by activating primary T cells with PHA and PMA. Addition of cationic liposomes together with RAdlacZ markedly enhanced the infection efficiency at lower MOI (1000) resulting in over 90% infection efficiency. Primary T cells express low levels of coxsackievirus and adenovirus receptor (CAR), a cell surface receptor for adenovirus fiber attachment, as well as vβ3 and vβ5 integrins, cellular receptors for adenovirus internalization. This suggests that adenovirus entry to T cells at high MOI is mediated by other mechanisms. In conclusion, these results demonstrate that genes can be efficiently transferred to primary lymphocytes by adenovirus vectors at high MOI or in combination with cationic liposomes. 相似文献
5.
6.
P. J. Goodfellow H. A. Nevanlinna P. Gorman D. Sheer G. Lam P. N. Goodfellow 《Annals of human genetics》1989,53(1):15-22
A cDNA corresponding to the β-subunit of the human fibronectin receptor (β-FNR) was used as a probe in Southern blot analysis of mouse/human somatic cell hybrid DNAs and in in situ hybridization to metaphase chrmosomes. The β-FNR cDNA detects sequences prosent on parent of the somatic cell hybrids. In situ hybridization refined the localization of human sequences reacting with the β-FNR cDNA to 10p11.2. The A-1A5 monoclonal antibody which recognizes the beta-subunit of the fibronectin receptor on the cell surface was used to confirm that the sequences present on chromosome 10 correspond to those required for expression of β-FNR. 相似文献
7.
Markus Mattila Leena Hakola Sari Niinist Heli Tapanainen Hanna-Mari Takkinen Suvi Ahonen Jorma Ilonen Jorma Toppari Riitta Veijola Mikael Knip Suvi M. Virtanen 《Nutrients》2021,13(3)
Our aim was to study the associations between maternal vitamin C and iron intake during pregnancy and the offspring’s risk of developing islet autoimmunity and type 1 diabetes. The study was a part of the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) prospective birth cohort including children genetically at risk of type 1 diabetes born between 1997–2004. The diets of 4879 mothers in late pregnancy were assessed with a validated food frequency questionnaire. The outcomes were islet autoimmunity and type 1 diabetes. Cox proportional hazards regression analysis adjusted for energy, family history of diabetes, human leukocyte antigen (HLA) genotype and sex was used for statistical analyses. Total intake of vitamin C or iron from food and supplements was not associated with the risk of islet autoimmunity (vitamin C: HR 0.91: 95% CI (0.80, 1.03), iron: 0.98 (0.87, 1.10)) or type 1 diabetes (vitamin C: 1.01 (0.87, 1.17), iron: 0.92 (0.78, 1.08)), neither was the use of vitamin C or iron supplements associated with the outcomes. In conclusion, no association was found between maternal vitamin C or iron intake during pregnancy and the risk of islet autoimmunity or type 1 diabetes in the offspring. 相似文献
8.
BACKGROUND: Suicide has been attributed to social and psychological factors but also to geophysical effects. Of the latter, changes in solar radiation and geomagnetic activities may contribute to the frequency and the seasonal pattern of suicides. METHODS: We studied with a population-based, nationwide analysis all the individuals who committed suicide (n=27,469) in Finland during the period of 1979 to 1999. The daily data on the number of suicides, and the mean and maximum levels of geomagnetic activity were compiled and modelled with Poisson regression using the number of inhabitants in each province as the denominator. Time series analysis of monthly numbers of suicides was carried out using a seasonal-trend decomposition procedure. RESULTS: There was a strong seasonal effect on suicide occurrence (P<0.00001), the risk of suicide being greatest in spring. The seasonal effect was most pronounced when the number of suicides was relatively low. High levels of solar radiation activity were associated with the increased risk of suicide (P=0.00001), but the effect of geomagnetic activity was weak. LIMITATIONS: No individual data on alcohol consumption or mental disorders were available. CONCLUSIONS: Suicide occurrence varies markedly by season and needs attention where prevention is concerned. 相似文献
9.
Weight and mortality in Finnish women 总被引:4,自引:0,他引:4
A Rissanen P Knekt M Heli?vaara A Aromaa A Reunanen J Maatela 《Journal of clinical epidemiology》1991,44(8):787-795
Mortality in relation to body mass index (BMI) was studied in 17,159 healthy Finnish women aged 25-79 followed up for a median of 12 years. Mortality from all cases was related to BMI only in non-smokers aged 25-64, among whom the mortality pattern was "U"-shaped, with a minimum in the second quintile of BMI (the reference range), and about 1.5 times higher in quintiles I and V. Most of the excess risk of mortality among overweight women was due to cardiovascular diseases. During the first 7 years of follow-up, and high risk (relative risk (RR) = 1.7, 95% confidence interval (CI) = 1.0-2.9 for quintile V compared to quintile II) depended on the association of BMI with the initial blood pressure level, but in the later years, the relative risk of cardiovascular death, ranging from 1.6 (95% CI = 1.0-2.5) for women in quintile III up to 2.6 (95% Ci = 1.7-4.0) for those in quintile V, was largely independent of the baseline levels of the main biological risk factors. The excess mortality among thin women under the age of 65 was mainly due to non-cardiovascular diseases (RR = 1.7, 95% CI = 1.2-2.3 for quintile I compared to quintile II) and was not attributable to antecedent disease, smoking or the biological risk factors studied. Among women aged 65 and over, overall mortality varied little with BMI, but thinness seemed to predict deaths from cancers (RR = 1.6, 95% CI = 0.9-3.0).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
10.
S. Roth P. Kristo A. Auranen M. Shayehgi S. Seal N. Collins R. Barfoot N. Rahman P. J. Klemi S. Gr??nman L. Sarantaus H. Nevanlinna R. Butzow A. Ashworth M. R. Stratton L. A. Aaltonen 《British journal of cancer》1998,77(8):1199-1202
Inherited susceptibility to ovarian cancer has been associated with germline defects at several loci. The major known ovarian cancer susceptibility gene is BRCA1 on chromosome 17q, which confers a risk of approximately 60% by the age of 70 years. Truncating mutations in BRCA2 on chromosome 13q also predispose to ovarian cancer, although they confer a lower risk than mutations in BRCA1. We have studied the molecular basis of ovarian cancer predisposition in a Finnish family with three affected sisters. Analysis of polymorphic markers provided evidence against linkage to BRCA1, but the sibship was consistent with linkage to BRCA2. Conformation-sensitive gel electrophoresis was used to screen the entire coding sequence of BRCA2. A G to A transition at nucleotide 8702 was observed, which is predicted to convert glycine 2901 to aspartate in the encoded protein. This sequence variant was not detected in 220 cancer-free Finnish control individuals, or in several hundred cancer families of many nationalities previously screened for BRCA2 mutations. Taken together with the fact that this amino acid residue and the surrounding region of BRCA2 is identical in mouse and chicken, the data suggest that this alteration is a disease-causing BRCA2 missense mutation. Previously published data indicate that the risks of breast and ovarian cancer conferred by BRCA2-truncating mutations varies with the position of the mutation in the gene. The missense mutation reported here suggests that the BRCA2 domain including and surrounding glycine 2901 may be more important in preventing neoplastic transformation in ovarian epithelium than in breast epithelium. 相似文献