首页 | 官方网站   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   7118篇
  免费   863篇
  国内免费   270篇
医药卫生   8251篇
  2024年   36篇
  2023年   263篇
  2022年   332篇
  2021年   590篇
  2020年   502篇
  2019年   426篇
  2018年   410篇
  2017年   367篇
  2016年   338篇
  2015年   280篇
  2014年   334篇
  2013年   843篇
  2012年   271篇
  2011年   324篇
  2010年   243篇
  2009年   223篇
  2008年   234篇
  2007年   217篇
  2006年   231篇
  2005年   185篇
  2004年   204篇
  2003年   158篇
  2002年   149篇
  2001年   156篇
  2000年   108篇
  1999年   100篇
  1998年   83篇
  1997年   85篇
  1996年   88篇
  1995年   67篇
  1994年   55篇
  1993年   43篇
  1992年   34篇
  1991年   35篇
  1990年   31篇
  1989年   20篇
  1988年   24篇
  1987年   13篇
  1986年   19篇
  1985年   19篇
  1984年   26篇
  1983年   13篇
  1982年   13篇
  1981年   12篇
  1980年   10篇
  1979年   10篇
  1978年   7篇
  1977年   11篇
  1976年   7篇
  1972年   1篇
排序方式: 共有8251条查询结果,搜索用时 46 毫秒
21.
Langerhans cell sarcoma in a patient who underwent transplantation   总被引:1,自引:0,他引:1  
Langerhans cell sarcoma is a rare, aggressive tumour that may metastasize to many organs, likely leading to death of the patient within 1 year. We present the first case described in the literature in a patient who underwent transplantation.  相似文献   
22.
目的观察比较泼尼松联用硫唑嘌呤和大剂量静脉用免疫球蛋白(IVIG)对扩张型心肌病(DCM)患儿心功能及预后的影响。方法将DCM患儿20例分为治疗Ⅰ和Ⅱ组,分别在传统抗心衰治疗基础上加泼尼松联用硫唑嘌呤和大剂量IVIG,治疗1个疗程后评价心功能,检测治疗前后左房横径(LA)、左室舒张期内径(LV)、左室射血分数(LVEF)、心脏指数(CI),并计算其治疗前后变化。所有病例随访1年,计算1年存活率。结果治疗Ⅱ组心功能明显优于治疗Ⅰ组(P均<0.05);两组LA、LV、LVEF和CI治疗后较治疗前均有明显改善(P均<0.05);治疗Ⅰ组各参数变化明显低于治疗Ⅱ组(P均<0.05),其1年存活率明显低于治疗组Ⅱ(P<0.05)。结论泼尼松联用硫唑嘌呤和大剂量IVIG均能改善DCM患儿心功能,但IVIG疗效优于泼尼松联用硫唑嘌呤。  相似文献   
23.
Systemic lupus erythematosus (SLE) is a complex disease whichhas posed a continuing challenge to scientists and cliniciansof diverse areas of specialization. It serves as a model forthe study of the mechanisms of autoimmunity—providingan important basis for the development of novel targeted therapiesin lupus and related conditions. The pathophysiology of SLE stems from the abnormal clearanceof apoptotic cells and/or endothelial activation. Material fromdying cells such as apoptotic blebs that are not efficientlyremoved may act as antigenic stimuli and lead to the developmentof autoantibodies with consequent formation of immune complexesand an inflammatory response in a variety of organ systems [1].This  相似文献   
24.
Although several studies have demonstrated the efficacy of subcutaneous immunotherapy in allergic asthma, few have shown the same benefit using sublingual immunotherapy (SLIT) in asthmatic patients. This study was conducted to assess the efficacy of house dust mite (HDM) SLIT in addition to allergen avoidance and standard pharmacologic treatment. A double-blind, placebo-controlled trial was performed in 111 children (aged 5-15 yr) with HDM-induced mild-to-moderate asthma. After a 4-week baseline phase, patients were randomly assigned to receive SLIT with tablets of HDM extract (n = 55) or placebo (n = 56) for 18 months. Pharmacologic treatment was adjusted every 3 months following a step-down approach. Asthma symptom scores, reduction in use of inhaled corticosteroids and inhaled beta(2)-agonists, rhinitis symptoms, lung function tests, skin sensitivity to HDM, dust mite-specific immunoglobulin (Ig) E and IgG(4), and quality of life (QoL) were assessed during the study. After 18 months of treatment, diurnal and nocturnal asthma symptoms scores did not show significant differences between SLIT and placebo groups. Inhaled corticosteroids and inhaled beta(2)-agonists use was reduced in both groups without significant differences between groups. There were no significant differences in lung function (forced expiratory volume in 1 s and peak flow rate variations) between groups. Rhinitis symptom score decreased in both groups, with no difference between the two groups. The severity dimension of QoL was significantly improved in the SLIT group (age 6-12 yr). SLIT induced a significant reduction of skin sensitivity to HDM (p < 0.01) and a significant increase in HDM-specific IgE and IgG(4) antibodies (p < 0.001) in the SLIT group compared with the placebo group. SLIT was well tolerated with mild/moderate local adverse events. No severe systemic reactions were reported. This study indicates that, when mild-moderate asthmatic children are optimally controlled by pharmacologic treatment and HDM avoidance, SLIT does not provide additional benefit, despite a significant reduction in allergic response to HDM. Under such conditions, only a complete, but ethically unfeasible, discontinuation of inhaled corticosteroid would have demonstrated a possible benefit of SLIT.  相似文献   
25.
T lymphocytes play a fundamental role in the initiation and regulation of chronic inflammatory responses in patients with asthma. CD69 is an early marker of T‐cell activation. The levels of intercellular adhesion molecule‐1 (ICAM‐1, CD54) and L ‐selectin have been reported to increase in patients with allergic diseases and asthma. The present study was therefore undertaken to investigate the expression of CD69, CD54, and L ‐selectin by T lymphocytes of children with asthma, before and after immunotherapy. Eighteen children newly diagnosed with asthma, 11 good and nine poor responders to immunotherapy, and 16 normal subjects, were enrolled in this study. The percentages of CD69+, CD54+, and CD62L+ cells in T lymphocytes were measured by using flow cytometry. The levels of CD69, CD54, and CD62L in serum and culture supernatants were determined by using enzyme‐linked immunosorbent assay (ELISA). The expression of CD69 and CD54 on CD3+ T lymphocytes was significantly higher in children with asthma than in control patients. All the patient groups expressed (spontaneously and following stimulation with phorbol myristate acetate and ionomycin together with mite‐extract proteins) greater amounts of CD69 and CD54 than did control subjects. With long‐term immunotherapy, the percentages of CD69+ and CD54+ T lymphocytes were significantly lower in patients with a good response to immunotherapy. Our results also showed significantly lower serum L ‐selectin levels following immunotherapy. In conclusion, successful immunotherapy resulted in decreased expression and production of CD69 and CD54. These results may explain, in part, the clinical efficacy of immunotherapy.  相似文献   
26.
The current standard systemic therapeutic modalities for psoriasis have many potential side effects. Progress made in the understanding of the pathophysiology of psoriasis as a T‐cell‐mediated dermatosis provide options for new more precise therapeutic approaches. These immunological therapeutic strategies involve the inhibition/depletion of activated T‐lymphocytes, the inhibition of antigen presentation and thus the regulation of T‐cell activation, the inhibition of adhesion of inflammatory cells, the inhibition of effects of proinflammatory mediators and the administration of antiinflammatory cytokines. This article summarizes these new systemic therapeutic approaches. Clinical results in the early studies have been mixed. In the next years further results of phase II‐ and phase III‐studies may be expected, which should allow better assessment of the potential of those particular approaches. Some of these approaches could lead to the approval of new drugs to treat psoriasis and to enhance or replace already existing therapeutic options. Furthermore results of therapeutic experiments should contribute to a better understanding of the disease. As we learn which mechanisms are more or less important for the disease, we will be better able to plan intervention strategies.  相似文献   
27.
Background: We examined alternative methods of delivering cytokines as an adjunct for priming lymph node (LN) cells draining sites of vaccine inoculation for the purpose of generating immune cells for adoptive immunotherapy. Methods: Using syngeneic murine tumors we examined the ability of IL-2, IL-4, or GM-CSF delivered locally to a site of tumor inoculum to induce antitumor reactive draining LN cells. Mice were inoculated subcutaneously with tumor cells transduced to secrete cytokine; tumor cells admixed with fibroblasts transduced to secrete cytokine; or intralesional inoculation of cytokine in established tumor to induce sensitized LN cells capable of mediating tumor regression in adoptive transfer. Results: Both IL-4 and GM-CSF cytokines were effective in enhancing the antitumor reactivity of vaccine-primed LN cells compared to IL-2, which was ineffective. The local delivery of GM-CSF by autocrine or paracrine secretion of genetically engineered cells, as well as direct intratumoral delivery was capable of upregulating LN sensitization compared to systemic administration, which did not. Conclusions: The local delivery of GM-CSF as an adjuvant for tumor vaccination can be accomplished by various methods, including direct injection, which avoids the need for gene transfer.  相似文献   
28.
肿瘤浸润性淋巴细胞(TIL)经白细胞介素2(IL-2)体外培养后具有很强的体内外抗肿瘤作用,且有一定的靶细胞特异性,其抗肿瘤效果强于淋巴因子激活的杀伤细胞即LAK细胞(P<0.01)。从瘤体中新鲜分离到的TIL对自体肿瘤细胞的杀伤活性极低,经IL-2体外培养后,其杀伤活性逐渐增高,以培养至7~25d的杀伤活性最强,这与IL-2使TIL分泌3种抗癌淋巴因子包括IL-2、IFN-γ、淋巴毒素(LT)增加有关。体外培养25d后,TIL的抗肿瘤活性下降,实验表明这与培养过程中TIL的Lyt-2~+细胞(Tc)减少而L3T4~+细胞(T_H)增多有关。TIL经冻存复苏和IL-2体外培养后仍保持很强的抗肿瘤活性,冻存前后比较未见显著差异(P>0.05),这为间断地运用TIL治疗复发性、晚期肿瘤提供了一条可行的途径。  相似文献   
29.
甲型流流感病毒鼠肺适庆型75-39株治疗S37腹水型荷瘤小鼠,存活率达93.3%。体外实验观察流感病毒感染S37肿瘤细胞,到3天时S37细胞经胎盘蓝染色,100%的S37细胞死亡,而对照组肿瘤细胞染色率只有10%左右。  相似文献   
30.
Immunotherapy through oral routes is thought to be a valuable therapeutic option for asthma. The clinical and immunologic effects of sublingual immunotherapy (SLIT) in children with asthma caused by mites were evaluated in a double-blind, placebo-controlled study for 6 months. Patients (aged 6-12 yr) with mild-to-moderate asthma, with single sensitization to mite allergen, received either SLIT or placebo with a standardized Dermatophagoides pteronyssinus (D.p.)/D. farinae (D.f.) 50/50 extract. The cumulative dose was around 41824 IR, equivalent to 1.7 mg of D.p. and 3.0 mg of D.f. allergen. Symptom and medication scores were assessed throughout the study. Serum total immunoglobulin (Ig)E, eosinophil count, eosinophil cationic protein, specific IgE, specific IgG4, and skin sensitivity were evaluated before starting the treatment and after the treatment period. Twenty patients completed the study. At the beginning of the treatment, no differences were observed between the groups for symptom and medication scores, skin sensitivity, or immunologic parameters. After 6 months of treatment, there was a significant difference in nighttime asthma symptom scores and specific IgG4 (p < 0.05) in the SLIT group compared with the placebo group. Daytime symptom and medication scores, total IgE, eosinophil count, forced expiratory volume in 1 s, and mean evening peak expiratory flow rate reached significant differences in the SLIT group during the treatment period (p < 0.05). No severe adverse effects were reported. Our results revealed that treatment for 6 months with SLIT is clinically effective in decreasing asthmatic symptoms and medication use in children with mild-to-moderate asthma because of mite sensitivity. The clinical usefulness of this form of immunotherapy and the mechanism underlying its immunologic effects deserve further studies.  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-23

京公网安备 11010802026262号