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   591篇
  免费   33篇
  国内免费   2篇
耳鼻咽喉   23篇
儿科学   25篇
妇产科学   20篇
基础医学   93篇
口腔科学   5篇
临床医学   70篇
内科学   89篇
皮肤病学   9篇
神经病学   20篇
特种医学   12篇
外科学   49篇
综合类   2篇
一般理论   1篇
预防医学   111篇
眼科学   1篇
药学   40篇
肿瘤学   56篇
  2022年   4篇
  2021年   24篇
  2020年   4篇
  2019年   13篇
  2018年   16篇
  2017年   8篇
  2016年   12篇
  2015年   20篇
  2014年   20篇
  2013年   34篇
  2012年   49篇
  2011年   48篇
  2010年   19篇
  2009年   21篇
  2008年   33篇
  2007年   36篇
  2006年   30篇
  2005年   39篇
  2004年   27篇
  2003年   33篇
  2002年   27篇
  2001年   3篇
  2000年   6篇
  1999年   6篇
  1998年   4篇
  1997年   3篇
  1996年   5篇
  1995年   6篇
  1994年   10篇
  1993年   5篇
  1991年   7篇
  1990年   4篇
  1989年   9篇
  1988年   5篇
  1987年   5篇
  1986年   3篇
  1985年   2篇
  1983年   2篇
  1981年   4篇
  1980年   1篇
  1979年   1篇
  1978年   4篇
  1977年   2篇
  1976年   2篇
  1975年   1篇
  1973年   1篇
  1971年   1篇
  1970年   1篇
  1967年   1篇
  1949年   1篇
排序方式: 共有626条查询结果,搜索用时 15 毫秒
21.
22.
Treatments offered at the Maharishi Ayurveda Health Centre in Norway are based on Maharishi Vedic Medicine (MVM). MVM is a consciousness-based revival by Maharishi Mahesh Yogi, the founder of the Transcendental Meditation (TM) program of the ancient Ayurvedic medicine tradition in India. To extend from 6 to 24 months, a pilot study of the effects of the treatment program at the Health Centre on fibromyalgia. Retesting 2 years after a clinical trial. In this intention to treat study, 31 women with a diagnosis of fibromyalgia received an individually tailored program of (1) physiological purification therapy (Maharishi Panchakarma) and (2) Ayurvedic recommendations regarding daily routine and diet including a novel approach to food intolerance. Five subjects chose to learn TM for stress reduction, pain management and personal development. All were recommended Ayurvedic herbal products for follow-up treatment. A modified Fibromyalgia Impact Questionnaire (FIQ) that included seven dimensions. Scores at 24 months follow-up were compared with pre-treatment scores. At 24-months follow-up, there were significant reductions (26% to 44%) in six of the seven fibromyalgia dimensions: impairment of working ability, pain, tiredness, morning tiredness, stiffness and anxiety. The 7th, depression, decreased 32% (borderline significant). At 24 months, the four subjects who continued practising TM, had almost no symptoms and significantly lower FIQ change scores (−92% to 97%) than the non-meditators on all outcomes. This pilot study suggests that the treatments and health promotion programs offered at the Maharishi Ayurveda Health Centre in Norway lead to long-term reductions in symptoms of fibromyalgia, which is considered a treatment-resistant condition, and further studies are warranted.  相似文献   
23.
24.
The naïve pluripotent state has been shown in mice to lead to broad and more robust developmental potential relative to primed mouse epiblast cells. The human naïve ES cell state has eluded derivation without the use of transgenes, and forced expression of OCT4, KLF4, and KLF2 allows maintenance of human cells in a naïve state [Hanna J, et al. (2010) Proc Natl Acad Sci USA 107(20):9222–9227]. We describe two routes to generate nontransgenic naïve human ES cells (hESCs). The first is by reverse toggling of preexisting primed hESC lines by preculture in the histone deacetylase inhibitors butyrate and suberoylanilide hydroxamic acid, followed by culture in MEK/ERK and GSK3 inhibitors (2i) with FGF2. The second route is by direct derivation from a human embryo in 2i with FGF2. We show that human naïve cells meet mouse criteria for the naïve state by growth characteristics, antibody labeling profile, gene expression, X-inactivation profile, mitochondrial morphology, microRNA profile and development in the context of teratomas. hESCs can exist in a naïve state without the need for transgenes. Direct derivation is an elusive, but attainable, process, leading to cells at the earliest stage of in vitro pluripotency described for humans. Reverse toggling of primed cells to naïve is efficient and reproducible.It has become clear with the derivation of mouse epiblast stem cells (mEpiSCs) that pluripotency encompasses more than one stage of development (1, 2). The earlier “naïve” stage represents the preimplantation inner cell mass, typified by mouse ES cells (mESCs), and the “primed,” the postimplantation epiblast, typified by mEpiSCs and human ES cells (hESCs). The challenge in naïve cell maintenance has been protecting cells from differentiation stimuli. This has been achieved in mESCs through exposure to leukemia inhibitory factor (LIF), whereas addition of extracellular signal-regulated kinase (MEK) and glycogen synthase kinase 3 (GSK3) inhibitors (2i) in defined medium allows the cells to attain a homogeneous ground state (3). Defining characteristics of the naïve/ground vs. primed states are shown in Fig. S1A. In humans, the naïve stage has been difficult to capture as a stable in vitro state.There are practical advantages that come with a human naïve state. Among them is ease of trypsin passage and developmental capacity. Whole animals can be generated from good naïve mESCs through tetraploid complementation (4), and mEpiSCs cannot contribute to chimerism. Being more comparable to mESCs, naïve hESCs will likely allow increased developmental potential and a more accurate correlation to mESC data.It has been reported that human induced pluripotent cells (h-iPSCs) can be maintained in the naïve state if the pluripotency-inducing transgenes are not silenced (5). Only recently have hESCs been maintained in a naïve state without transgenes (6). Our primary aim was to generate naïve hESCs not dependent upon transgenes for stable culture. We toggled existing human ESC and mouse mEpiSC lines back from the primed state to grow under the influence of 2i without the need for Activin A. This helped us to define appropriate culture conditions for human naïve cells and allowed the de novo derivation of a naïve hESC line, Elf1. We report on the naïve state of human ESCs capable of unlimited culture in 2i.  相似文献   
25.
In order to impede the increase in pertussis incidence in the adolescent group, a school-leaving booster dose administered at the age of 14 to 16 years will be introduced in Sweden in 2016. Preceding this introduction, an open-label, randomized, multicenter, clinical trial without a control group and with blinded analysis was performed, investigating both safety and immunogenicity. Reported here are the memory B-cell and serological responses detected in a smaller cohort (n = 34) of the 230 subjects recruited to the study. All subjects had received primary vaccination consisting of three doses of diphtheria–tetanus–5-component pertussis (DTaP5) vaccine, at 3, 5, and 12 months of age, and a tetanus–low-dose diphtheria–5-component pertussis (Tdap5) vaccine booster at 5.5 years. In this study, the subjects were randomly assigned and received either a Tdap1 or Tdap5 booster. Of the 230 participants, 34 subjects had samples available for evaluation of IgG-producing memory B-cell responses. Both vaccine groups had significant increases in pertussis toxin-specific serum IgG levels, but only the 1-component group showed significant increases in pertussis toxin-specific memory B cells. The 5-component group had significant increases in filamentous hemagglutinin- and pertactin-specific memory B-cell and serum IgG levels; these were not seen in the 1-component group, as expected. In conclusion, this study shows that a 5th consecutive dose of an acellular pertussis vaccine induces B-cell responses in vaccinated adolescents. (This study has been registered at EudraCT under registration no. 2008-008195-13 and at ClinicalTrials.gov under registration no. NCT00870350.)  相似文献   
26.
Melanoma and renal-cell carcinoma (RCC) are generally considered to be relatively immunogenic tumor types in humans. In the case of melanoma, many major histocompatibility complex (MHC) class I-restricted tumor-specific cytotoxic T lymphocytes (CTL) have been isolated from either tumor-infiltrating lymphocytes (TIL) or autologous peripheral blood lymphocytes (PBL). In contrast, such CTL have only incidentally been described in the case of RCC. It has often been reported that TIL lines isolated from RCC display non-MHC-restricted and non-specific activity. Here, we report the isolation and characterization of tumor-specific CTL from PBL of one RCC patient and from TIL of another RCC patient. CTL clones 263/17 and 263/45, isolated from the PBL of patient LE-9211, were restricted by HLA-B7. CTL clone 5E, isolated from the TIL of patient LE-8915, was restricted by HLA-B37. The autologous RCC cell lines were efficiently lysed by the CTL clones, whereas normal epithelial cells of the proximal tubuli matched for the restriction element and K562 were not. From a panel of allogeneic RCC cell lines, CTL 5E recognized MZ-1940-RCC. Reactivity to allogeneic RCC sharing HLA-B7 was also observed with CTL 263/17 and 263/45, both of which could lyse the HLA-B7-positive cell line MZ-1851-RCC. Our data provide evidence that common tumor antigens are recognized by CTL on RCC. © 1996 Wiley-Liss, Inc.  相似文献   
27.
Most patients with tuberous sclerosis complex (TSC) develop cortical tubers that cause severe neurological disabilities. It has been suggested that defects in neuronal differentiation and/or migration underlie the appearance of tubers. However, the precise molecular alterations remain largely unknown. Here, by combining cytological and immunohistochemical analyses of tubers from nine TSC patients (four of them diagnosed with TSC2 germline mutations), we show that alteration of microtubule biology through ROCK2 signalling contributes to TSC neuropathology. All tubers showed a larger number of binucleated neurons than expected relative to control cortex. An excess of normal and altered cytokinetic figures was also commonly observed. Analysis of centrosomal markers suggested increased microtubule nucleation capacity, which was supported by the analysis of an expression dataset from cortical tubers and control cortex, and subsequently linked to under‐expression of Rho‐associated coiled‐coil containing kinase 2 (ROCK2). Thus, augmented microtubule nucleation capacity was observed in mouse embryonic fibroblasts and human fibroblasts deficient in the Tsc2/TSC2 gene product, tuberin. Consistent with ROCK2 under‐expression, microtubule acetylation was found to be increased with tuberin deficiency; this alteration was abrogated by rapamycin treatment and mimicked by HDAC6 inhibition. Together, the results of this study support the hypothesis that loss of TSC2 expression can alter microtubule organization and dynamics, which, in turn, deregulate cell division and potentially impair neuronal differentiation. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd  相似文献   
28.
29.
30.
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