全文获取类型
收费全文 | 13918篇 |
免费 | 1043篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 65篇 |
儿科学 | 479篇 |
妇产科学 | 313篇 |
基础医学 | 1993篇 |
口腔科学 | 150篇 |
临床医学 | 1801篇 |
内科学 | 2680篇 |
皮肤病学 | 195篇 |
神经病学 | 1607篇 |
特种医学 | 306篇 |
外科学 | 1487篇 |
综合类 | 140篇 |
一般理论 | 32篇 |
预防医学 | 1623篇 |
眼科学 | 246篇 |
药学 | 934篇 |
中国医学 | 23篇 |
肿瘤学 | 930篇 |
出版年
2023年 | 115篇 |
2022年 | 91篇 |
2021年 | 415篇 |
2020年 | 226篇 |
2019年 | 372篇 |
2018年 | 380篇 |
2017年 | 273篇 |
2016年 | 283篇 |
2015年 | 351篇 |
2014年 | 460篇 |
2013年 | 712篇 |
2012年 | 1083篇 |
2011年 | 1061篇 |
2010年 | 530篇 |
2009年 | 504篇 |
2008年 | 851篇 |
2007年 | 901篇 |
2006年 | 818篇 |
2005年 | 782篇 |
2004年 | 759篇 |
2003年 | 712篇 |
2002年 | 675篇 |
2001年 | 153篇 |
2000年 | 136篇 |
1999年 | 162篇 |
1998年 | 156篇 |
1997年 | 133篇 |
1996年 | 109篇 |
1995年 | 88篇 |
1994年 | 79篇 |
1993年 | 87篇 |
1992年 | 99篇 |
1991年 | 94篇 |
1990年 | 80篇 |
1989年 | 103篇 |
1988年 | 72篇 |
1987年 | 74篇 |
1986年 | 84篇 |
1985年 | 67篇 |
1984年 | 77篇 |
1983年 | 76篇 |
1982年 | 76篇 |
1981年 | 72篇 |
1980年 | 56篇 |
1979年 | 57篇 |
1978年 | 47篇 |
1977年 | 39篇 |
1976年 | 35篇 |
1975年 | 47篇 |
1974年 | 38篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
21.
Body pain and treatment response in late-life depression. 总被引:2,自引:0,他引:2
Jordan F Karp Debra Weiner Karen Seligman Meryl Butters Mark Miller Ellen Frank Jacqueline Stack Benoit H Mulsant Bruce Pollock Mary Amanda Dew David J Kupfer Charles F Reynolds 《The American journal of geriatric psychiatry》2005,13(3):188-194
OBJECTIVE: The authors investigated the influence of body pain on 1) time to treatment response and 2) suicidal ideation, in late-life depression. They hypothesized that higher levels of body pain would predict a longer time to and lower likelihood of response, and increased levels of suicidal ideation. METHODS: Subjects (N=187) were older adult outpatients (age > or =69 years), with current episodes of major depression, who were openly treated with paroxetine up to 40 mg daily and weekly interpersonal psychotherapy. Response was defined as 3 consecutive weeks of Hamilton Rating Scale for Depression at < or =10. Body pain was measured with the Bodily Pain Index of the SF-36 quality-of-life assessment. Authors used survival-analysis models on the responder sample to test the effect of body pain on response, after controlling for severity of depression. RESULTS: Overall response rate was 75.4%. Nonresponders reported more severe pain at baseline. After covarying for severity of baseline depression, no effect was found for physical pain on time-to-response or degree of suicidality. Bodily pain remained stable during acute treatment for responders, independent of depression response to combination psychotherapy and antidepressant treatment. CONCLUSIONS: Older adult patients with higher levels of physical pain can still respond to antidepressant treatment; however, reported bodily pain may be associated with a more difficult-to-treat depression. 相似文献
22.
Catherine Beckers Clio Ribbens Béatrice André Stefaan Marcelis Olivier Kaye Luc Mathy Marie-Jo?lle Kaiser Roland Hustinx Jacqueline Foidart Michel G Malaise 《Journal of nuclear medicine》2004,45(6):956-964
The aim of this study was to assess synovitis by (18)F-FDG PET in an individual joint analysis and in a global analysis of rheumatoid arthritis (RA) disease activity and to compare (18)F-FDG PET parameters with clinical, biologic, and sonographic (US) rheumatoid parameters. METHODS: Three hundred fifty-six joints were assessed in 21 patients with active RA: the knees in all subjects and either wrists as well as metacarpophalangeal and proximal interphalangeal joints in 13 patients, or ankles and the first metatarsophalangeal joints in the remaining 8 patients. PET analysis consisted of a visual identification of (18)F-FDG uptake in the synovium and measurements of standardized uptake values (SUVs). Independent assessors performed the clinical and US examinations. RESULTS: PET positivity was found in 63% of joints, whereas 75%, 79%, and 56% were positive for swelling, tenderness, and US analysis, respectively. Both the rate of PET-positive joints and the SUV increased with the number of positive parameters present (swelling, tenderness, US positivity) and with the synovial thickness. The mean SUV was significantly higher in joints where a power Doppler signal was found. In a global PET analysis, the number of PET-positive joints and the cumulative SUV were significantly correlated with the swollen and tender joint counts, the patient and physician global assessments, the erythrocyte sedimentation rate and C-reactive protein serum levels, the disease activity score and the simplified disease activity index, the number of US-positive joints, and the cumulative synovial thickness. CONCLUSION: (18)F-FDG PET is a unique imaging technique that can assess the metabolic activity of synovitis and measure the disease activity in RA. 相似文献
23.
Steven JY Wang Claire Cornick Jacqueline O'Dowd Michael A Cawthorne Jonathan R S Arch 《Lipids in health and disease》2007,6(1):2
Background
Mice that lack acyl CoA:diacylglycerol acyltransferase (Dgat1 -/- mice) are reported to have a reduced body fat content and improved glucose tolerance and insulin sensitivity. Studies so far have focussed on male null mice fed a high fat diet and there are few data on heterozygotes. We compared male and female Dgat1 -/-, Dgat1 +/- and Dgat1 +/+ C57Bl/6 mice fed on either standard chow or a high fat diet. 相似文献24.
We examined relative weight and height in relation to subsequent breast cancer risk among 115,534 women 30 to 55 years of age and free from cancer in 1976. By 1984, six hundred fifty-eight premenopausal and 420 postmenopausal breast cancers were documented during 734,716 person-years. Among premenopausal women, risk of breast cancer decreased significantly with increasing relative weight (relative risk for the highest category was 0.6). A similar inverse association was seen for recalled relative weight at 18 years of age. Postmenopausal breast cancer was not associated with relative weight, either recent or at age 18. Height was not associated with breast cancer risk among premenopausal women and only weakly related among postmenopausal women. These data suggest that obesity among premenopausal and early postmenopausal women does not increase breast cancer risk substantially. 相似文献
25.
Performance standards for toric soft contact lenses. 总被引:1,自引:0,他引:1
Jacqueline Tan Eric Papas Nicole Carnt Isabelle Jalbert Cheryl Skotnitsky Maki Shiobara Edward Lum Brien Holden 《Optometry and vision science》2007,84(5):422-428
PURPOSE: To simplify the clinical assessment of toric soft contact lens (TSCL) on-eye behavior by establishing a set of standard clinical evaluation techniques. The likely performance range expected among the TSCL wearing population was determined for a series of lens designs and acceptable performance standards indicated for each variable. METHODS: Four prism-ballast, two peri-ballast and one dynamic stabilization TSCL designs were each worn by groups of 20 subjects in a nondispensing study. After 20 min of lens wear, lenses were assessed, in right eyes only, for subjective comfort (100-point scale), lens mislocation (degrees deviation from vertical) and rotational recovery after deliberate 30 degrees mislocation (degrees/10 blinks). The percentage of lenses orienting within +/-10 degrees of target orientation (zero rotation) and the variability of orientation (standard deviation of mislocation) were also calculated for each lens group. RESULTS: Based on partitioning of the data distributions for each variable, performance was designated as excellent, acceptable or poor. Corresponding performance cut-offs were determined at > or =90, 89 to 80, and <80 for subjective comfort, < or =+/-6 degrees , +/-7 degrees to 10 degrees , and >+/-10 degrees for mislocation, >10 degrees /10 blinks, 10 degrees to 6 degrees /10 blinks, and <6 degrees /10 blinks for rotational recovery. For groups of wearers the appropriate cut-offs were > or =90%, 89 to 70%, and <70% of lenses orienting within +/-10 degrees of target orientation and <+/-6 degrees , +/-6 degrees to 10 degrees , and >+/-10 degrees for variability of orientation. CONCLUSION: Techniques suitable for the evaluation of TSCL clinical performance have been described and guidelines for the assessment of such lenses established. In the process, we have identified potential performance differences that may relate to variations in TSCL design. 相似文献
26.
27.
ABSTRACT: This study used formative evaluation to identify channels and barriers to providing ongoing dietary guidance to pregnant teens in New Jersey. In phase one, 14 health and social service professionals participated in a focus group or interview about nutrition services for pregnant teens. Participants identified school nurses as potential providers of early and continuous dietary counseling to pregnant teen-agers, but delineated barriers to establishment and effectiveness of school-based, prenatal nutrition education. In phase two, school nurses were surveyed to assess their interest in, and perceptions of barriers to, providing nutrition education to pregnant adolescents. Two-hundred fifty-three nurses (71%) returned completed questionnaires. Results indicated that a significant proportion perceived a need for, and were interested in providing, nutrition education to pregnant students. Results from this formative research are being used to guide development of a school-based nutrition education program for pregnant teen-agers in New Jersey. 相似文献
28.
Summary. Platelet membranes provide procoagulant surfaces for the assembly and expression of the factor X-activating complex and promote the proteolytic activation and assembly of the prothrombinase complex resulting in normal hemostasis. Recent studies from our laboratory and others indicate that platelets possess specific, high-affinity, saturable, receptors for factors XI, XIa, IX, IXa, X, VIII, VIIIa, V, Va and Xa, prothrombin, and thrombin. Studies described in this review support the hypothesis that the factor X-activating complex on the platelet surface consists of three receptors (for the enzyme, factor IXa; the substrate, factor X; and the cofactor, factor VIIIa), the colocalization of which results in a 24 million-fold acceleration of the rate of factor X activation. Whether the procoagulant surface of platelets is defined exclusively by procoagulant phospholipids, or whether specific protein receptors exist for the coagulant factors and proteases, is currently unresolved. The interaction between coagulation proteins and platelets is critical to the maintenance of normal hemostasis and is pathogenetically important in human disease. 相似文献
29.
30.
A case of mosaic trisomy 2 diagnosed at amniocentesis in an abnormal fetus and confirmed in multiple fetal tissues 总被引:2,自引:0,他引:2
Jacqueline Robinson Helen Stewart Lynette Moore Lorraine Gaunt 《Clinical genetics》1997,51(6):417-420
Pseudomosaicism for trisomy 2 is a relatively common finding at amniocentesis. However, genuine trisomy 2 mosaicism is extremely rare. As a result, very few cases have been described and little information is available with which to counsel the parents of an affected fetus. We describe a case of mosaic trisomy 2 diagnosed at amniocentesis in a fetus with multiple anomalies on ultrasound scan. Following termination of pregnancy, the fetus was found to have mild dysmorphic features, together with an absent gall bladder, cystic left kidney, a 13th left rib and mild unilateral talipes. The presence of trisomy 2 cells was confirmed by both standard cytogenetic analysis and fluorescent in-situ hybridisation techniques in multiple fetal tissues, as well as in the cord and placenta. 相似文献