首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   11804篇
  免费   1023篇
  国内免费   65篇
耳鼻咽喉   150篇
儿科学   236篇
妇产科学   253篇
基础医学   1433篇
口腔科学   121篇
临床医学   1209篇
内科学   2530篇
皮肤病学   140篇
神经病学   962篇
特种医学   518篇
外科学   2272篇
综合类   162篇
一般理论   12篇
预防医学   872篇
眼科学   256篇
药学   759篇
中国医学   26篇
肿瘤学   981篇
  2024年   15篇
  2023年   158篇
  2022年   238篇
  2021年   609篇
  2020年   319篇
  2019年   513篇
  2018年   579篇
  2017年   395篇
  2016年   393篇
  2015年   443篇
  2014年   610篇
  2013年   716篇
  2012年   1097篇
  2011年   1023篇
  2010年   586篇
  2009年   479篇
  2008年   693篇
  2007年   672篇
  2006年   589篇
  2005年   552篇
  2004年   488篇
  2003年   419篇
  2002年   317篇
  2001年   94篇
  2000年   78篇
  1999年   96篇
  1998年   51篇
  1997年   52篇
  1996年   53篇
  1995年   39篇
  1994年   29篇
  1993年   30篇
  1992年   42篇
  1991年   39篇
  1990年   45篇
  1989年   31篇
  1988年   31篇
  1987年   31篇
  1986年   25篇
  1985年   22篇
  1984年   23篇
  1983年   24篇
  1982年   15篇
  1981年   14篇
  1980年   10篇
  1979年   16篇
  1978年   13篇
  1977年   12篇
  1976年   16篇
  1972年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Monoclonal antibodies OKT11 (γ1) and OKT11A (γ2) are described and appear to have similar binding specificities. They bind, in immunofluorescence, with >95% of infant thymocytes, staining both cortical and medullary cells, 65-80% of blood lymphocytes and selectively stain the T cell-dependent paracortical areas of tonsil. A small proportion (9-12%) of bone marrow lymphocytes stain, but this population excludes the terminal transferase-positive cells. Both the γ1 and γ2 antibodies stain the surface membrane Ig-negative lymphocytes in blood and tonsil and are able to block sheep E rosette formation (to normal or leukemic T cells). In contrast, other monoclonal anti-T reagents tested (OKT1, OKT3, OKT4, OKT6, OKT8, OKT9, OKT10) did not block E rosette formation. E rosette formation and OKT11 binding are coincident on T-ALL cell lines and both are trypsin-sensitive. In a series of 145 leukemias and 26 leukemic cell lines investigated, only leukemias with a T cell phenotype including E rosette positivity were reactive with OKT11 and OKT11A. OKT11A binds to a polypeptide of approximately 50000 molecular weight on thymic lymphocytes. This structure may carry the recognition site for sheep erythrocytes. These antibodies provide additional useful markers for T cell analysis and are of potential therapeutic value.  相似文献   
62.
63.
64.
65.
Omalizumab in asthma   总被引:1,自引:0,他引:1  
Omalizumab is a humanized mouse monoclonal antibody that binds specifically to the constant region of the immunoglobulin (Ig)E heavy chain. Omalizumab exerts its effects by reducing free serum IgE levels and FcepsilonRI expression on several cell types. These effects have been shown to result in decreased airway inflammation and clinical improvement. In multiple studies, omalizumab has been shown to be efficacious in the treatment of moderate-to-severe persistent asthma and is currently approved by the US Food and Drug Administration for the treatment of moderate-to-severe allergic asthma in patients age 12 yr and older. Moreover, omalizumab has been demonstrated to be effective in the treatment of children and adults with seasonal and perennial allergic rhinitis. Postmarketing surveillance has shown omalizumab to be a relatively safe and well-tolerated medication.  相似文献   
66.
A factor of nominal molecular weight 6K–10K Daltons, isolated from bovine aorta, has previously been shown to inhibit neovascularization and tumor growth in vivo and the growth of some tumor cells as well as endothelial cells in culture. This factor, termed A-10, was tested alone and in combination with Adriamycin against TA3Ha mammary adenocarcinoma cells in tissue culture. It was found to have cytotoxicity additive to that of Adriamycin in inhibiting the growth of these cells. In vitro and animal studies show that the sequence of Adriamycin A-10 is superior to either agent alone in delaying the appearance of palpable tumors after subcutaneous injection of 105 pre-treated tumor cells in the tail of strain A mice. While the growth rate of the primary tumor was not affected by such treatment, survival was prolonged to a greater degree by the this sequence than by either of these agents used alone. A-10 treatment reduced the number of metastases to the adrenal gland but not to lung, liver, or lymph nodes. It did, however, reduce the size of metastases to para-aortic lymph nodes.  相似文献   
67.
Rice bran exhibits chemopreventive properties that may help to prevent colorectal cancer (CRC), and a short-term rice bran dietary intervention may promote intestinal health via modification of the intestinal microbiota. We conducted a pilot, double-blind, randomised placebo-controlled trial to assess the feasibility of implementing a long-term (24-week) rice bran dietary intervention in Chinese subjects with a high risk of CRC, and to examine its effects on the composition of their intestinal microbiota. Forty subjects were randomised into the intervention group (n = 19) or the control group (n = 20). The intervention participants consumed 30 g of rice bran over 24-h intervals for 24 weeks, whilst the control participants consumed 30 g of rice powder on the same schedule. High rates of retention (97.5%) and compliance (≥91.3%) were observed. No adverse effects were reported. The intervention significantly enhanced the intestinal abundance of Firmicutes and Lactobacillus, and tended to increase the Firmicutes/Bacteroidetes ratio and the intestinal abundance of Prevotella_9 and the health-promoting Lactobacillales and Bifidobacteria, but had no effect on bacterial diversity. Overall, a 24-week rice bran dietary intervention was feasible, and may increase intestinal health by inducing health-promoting modification of the intestinal microbiota. Further larger-scale studies involving a longer intervention duration and multiple follow-up outcome assessments are recommended.  相似文献   
68.
Scope: B vitamers are co-enzymes involved in key physiological processes including energy production, one-carbon, and macronutrient metabolism. Studies profiling B vitamers simultaneously in parent–child dyads are scarce. Profiling B vitamers in parent–child dyads enables an insightful determination of gene–environment contributions to their circulating concentrations. We aimed to characterise: (a) parent–child dyad concordance, (b) generation (children versus adults), (c) age (within the adult subgroup (age range 28–71 years)) and (d) sex differences in plasma B vitamer concentrations in the CheckPoint study of Australian children. Methods and Results: 1166 children (11 ± 0.5 years, 51% female) and 1324 parents (44 ± 5.1 years, 87% female) took part in a biomedical assessment of a population-derived longitudinal cohort study: The Growing Up in Australia’s Child Health CheckPoint. B vitamer levels were quantified by UHPLC/MS-MS. B vitamer levels were weakly concordant between parent–child pairs (10–31% of variability explained). All B vitamer concentrations exhibited generation-specificity, except for flavin mononucleotide (FMN). The levels of thiamine, pantothenic acid, and 4-pyridoxic acid were higher in male children, and those of pantothenic acid were higher in male adults compared to their female counterparts. Conclusion: Family, age, and sex contribute to variations in the concentrations of plasma B vitamers in Australian children and adults.  相似文献   
69.
Maternal and Child Health Journal - Alcohol use during pregnancy is a critical public health issue that results in several adverse outcomes for both mother and child. While the prevalence of and...  相似文献   
70.

The Family Check-Up 4 Health (FCU4Health) is an adaptation of the Family Check-Up (FCU) for delivery in primary care settings. While maintaining the original FCU’s focus on parenting and child behavioral health, we added content targeting health behaviors. This study evaluated whether the adapted FCU maintained positive effects on parenting (positive behavior support, limit setting, parental warmth) and child behavioral health (self-regulation, conduct problems, emotional problems). Pediatric (6–12 years) primary care patients with a BMI?≥?85th%ile (n?=?240) were recruited from primary care clinics in Phoenix. Children were 75% Latino, 49% female, and 73% Medicaid recipients. This type 2 effectiveness-implementation hybrid trial compared families randomized to FCU4Health (n?=?141) or usual care (n?=?99). FCU4Health was delivered over a period of 6 months. This study focuses on a priori secondary outcomes included parenting and child behavioral health targets of the original FCU, assessed at baseline and 3, 6, and 12 months. Significant improvements were found for the FCU4Health condition, compared to usual care, in parenting from baseline to the 3-month assessment [β?=?.17 (.01; .32)]. Parenting predicted improvements in child self-regulation at 6-months [β?=?.17 (.03; .30)], which in turn predicted reductions in conduct problems [β?=?? .38 (? .51; ? .23)] and emotional problems [β?=?? .24 (? .38; ? .09)] at 12 months. Ethnicity and language of delivery (English or Spanish) did not moderate these effects. The FCU4Health can improve parenting and child behavioral health outcomes when delivered in primary care.

Trial Registration Trial registration number: NCT03013309 ClinicalTrials.gov

  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号