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   83篇
  免费   6篇
  国内免费   1篇
  2022年   1篇
  2021年   3篇
  2019年   1篇
  2018年   4篇
  2017年   2篇
  2016年   5篇
  2015年   7篇
  2014年   9篇
  2013年   1篇
  2012年   4篇
  2011年   4篇
  2010年   3篇
  2009年   1篇
  2008年   1篇
  2007年   4篇
  2006年   1篇
  2005年   1篇
  2003年   3篇
  2002年   1篇
  2001年   1篇
  2000年   3篇
  1999年   3篇
  1998年   1篇
  1996年   1篇
  1993年   1篇
  1992年   2篇
  1991年   2篇
  1990年   1篇
  1989年   2篇
  1987年   1篇
  1986年   2篇
  1985年   1篇
  1984年   3篇
  1982年   1篇
  1981年   2篇
  1976年   1篇
  1967年   2篇
  1966年   1篇
  1964年   1篇
  1961年   1篇
  1947年   1篇
排序方式: 共有90条查询结果,搜索用时 171 毫秒
41.
Human mesenchymal stem cells (MSCs) are a promising candidate for cell-based transplantation and regenerative medicine therapies. Thus in the present study Wharton’s Jelly Mesenchymal Stem Cells (WJ-MSCs) have been derived from extra embryonic umbilical cord matrix following removal of both arteries and vein. Also, to overcome the clinical limitations posed by fetal bovine serum (FBS) supplementation because of xenogeneic origin of FBS, usual FBS cell culture supplement has been replaced with human platelet lysate (HPL). Apart from general characteristic features of bone marrow-derived MSCs, wharton jelly-derived MSCs have the ability to maintain phenotypic attributes, cell growth kinetics, cell cycle pattern, in vitro multilineage differentiation plasticity, apoptotic pattern, normal karyotype-like intrinsic mesenchymal stem cell properties in long-term in vitro cultures. Moreover, the WJ-MSCs exhibited the in vitro multilineage differentiation capacity by giving rise to differentiated cells of not only mesodermal lineage but also to the cells of ectodermal and endodermal lineage. Also, WJ-MSC did not present any aberrant cell state upon in vivo transplantation in SCID mice and in vitro soft agar assays. The immunomodulatory potential assessed by gene expression levels of immunomodulatory factors upon exposure to inflammatory cytokines in the fetal WJ-MSCs was relatively higher compared to adult bone marrow-derived MSCs. WJ-MSCs seeded on decellularized amniotic membrane scaffold transplantation on the skin injury of SCID mice model demonstrates that combination of WJ-MSCs and decellularized amniotic membrane scaffold exhibited significantly better wound-healing capabilities, having reduced scar formation with hair growth and improved biomechanical properties of regenerated skin compared to WJ-MSCs alone. Further, our experimental data indicate that indocyanin green (ICG) at optimal concentration can be resourcefully used for labeling of stem cells and in vivo tracking by near infrared fluorescence non-invasive live cell imaging of labelled transplanted cells, thus proving its utility for therapeutic applications.  相似文献   
42.

Introduction

Herpes simplex virus type 1 encephalitis presents acutely in patients who are immunocompetent. We report what we believe to be the first published case of a subacute course of herpes simplex virus type 1 encephalitis in a patient with asymptomatic chronic lymphocytic leukemia who subsequently developed multiple sclerosis.

Case presentation

A 49-year-old Caucasian woman with a history of fever blisters presented to the emergency department with a history of left temporal headache for four weeks, and numbness of the left face and leg for two weeks. A complete blood count revealed white blood cell count of 11,820 cells/mL, with an absolute lymphocyte count of 7304 cells/mL. The cerebrospinal fluid contained 6 white blood cells/μL, 63 red blood cells/μL, 54 mg glucose/dL, and 49 mg total protein/dL. Magnetic resonance imaging of the brain revealed meningoencephalitis and bilateral ventriculitis. Cerebrospinal fluid polymerase chain reaction for herpes simplex virus type 1 was positive, and the patient's symptoms resolved after ten days of treatment with parenteral aciclovir. Incidental findings on peripheral blood smear and flow cytometry testing confirmed chronic lymphocytic leukemia. One month later, she developed bilateral numbness of the hands and feet; a repeat cerebrospinal fluid polymerase chain reaction for herpes simplex virus type 1 at this time was negative. A repeat magnetic resonance imaging scan showed an expansion of the peri-ventricular lesions, and the cerebrospinal fluid contained elevated oligoclonal bands and myelin basic protein. A brain biopsy revealed gliosis consistent with multiple sclerosis, and the patient responded to treatment with high-dose parenteral steroids.

Conclusion

Herpes simplex virus type 1 encephalitis is a rare presentation of chronic lymphocytic leukemia. Our patient had an atypical, subacute course, presumably due to immunosuppression from chronic lymphocytic leukemia. This unusual case of herpes simplex virus type 1 encephalitis emphasizes the importance of T cell function in diseases of immune dysregulation and autoimmunity such as chronic lymphocytic leukemia and multiple sclerosis. It raises the question of whether atypical presentations of herpes simplex virus encephalitis warrant deliberations on immunocompetence. The development of multiple sclerosis in our patient so soon after she received treatment for herpes simplex virus type 1 encephalitis raises the possibility that herpes simplex virus type 1 encephalitis in an immunosuppressed patient may trigger multiple sclerosis.
  相似文献   
43.

Background

In fish, the most studied production traits in terms of heritability are body weight or growth, stress or disease resistance, while heritability of cortisol levels, widely used as a measure of response to stress, is less studied. In this study, we have estimated heritabilities of two growth traits (body weight and length) and of cortisol response to confinement stress in the European sea bass.

Findings

The F1 progeny analysed (n = 922) belonged to a small effective breeding population with contributions from an unbalanced family structure of just 10 males and 2 females. Heritability values ranged from 0.54 (±0.21) for body weight to 0.65 (±0.22) for standard body length and were low for cortisol response i.e. 0.08 (±0.06). Genetic correlations were positive (0.94) between standard body length and body weight and negative between cortisol and body weight and between cortisol and standard body length (−0.60 and −0.55, respectively).

Conclusion

This study confirms that in European sea bass, heritability of growth-related traits is high and that selection on such traits has potential. However, heritability of cortisol response to stress is low in European sea bass and since it is known to vary greatly among species, further studies are necessary to understand the reasons for these differences.  相似文献   
44.
45.
46.
47.
48.
49.
Cuatro Ciénegas Basin (CCB) is a desert ecosystem that hosts a large diversity of water bodies. Many surface waters in this basin have imbalanced nitrogen (N) to phosphorus (P) stoichiometry (total N:P > 100 by atoms), where P is likely to be a limiting nutrient. To investigate the effects of nutrient stoichiometry on planktonic and sediment ecosystem components and processes, we conducted a replicated in situ mesocosm experiment in Lagunita, a shallow pond located in the southwest region of the basin. Inorganic N and P were periodically added to mesocosms under three different N:P regimes (P only, N:P = 16 and N:P = 75) while the control mesocosms were left unamended. After three weeks of fertilization, more than two thirds of the applied P was immobilized into seston or sediment. The rapid uptake of P significantly decreased biomass C:P and N:P ratios, supporting the hypothesis that Lagunita is P-limited. Meanwhile, simultaneous N and P enrichment significantly enhanced planktonic growth, increasing total planktonic biomass by more than 2-fold compared to the unenriched control. With up to 76% of added N sequestered into the seston, it is suspected that the Lagunita microbial community also experienced strong N-limitation. However, when N and P were applied at N:P = 75, the microbes remained in a P-limitation state as in the untreated control. Two weeks after the last fertilizer application, seston C:P and N:P ratios returned to initial levels but chlorophyll a and seston C concentrations remained elevated. Additionally, no P release from the sediment was observed in the fertilized mesocosms. Overall, this study provides evidence that Lagunita is highly sensitive to nutrient perturbation because the biota is primarily P-limited and experiences a secondary N-limitation despite its high TN:TP ratio. This study serves as a strong basis to justify the need for protection of CCB ecosystems and other low-nutrient microbe-dominated systems from anthropogenic inputs of both N and P.  相似文献   
50.
Bats are likely natural hosts for a range of zoonotic viruses such as Marburg, Ebola, Rabies, as well as for various Corona- and Paramyxoviruses. In 2009/10, researchers discovered RNA of two novel influenza virus subtypes – H17N10 and H18N11 – in Central and South American fruit bats. The identification of bats as possible additional reservoir for influenza A viruses raises questions about the role of this mammalian taxon in influenza A virus ecology and possible public health relevance. As molecular testing can be limited by a short time window in which the virus is present, serological testing provides information about past infections and virus spread in populations after the virus has been cleared. This study aimed at screening available sera from 100 free-ranging, frugivorous bats (Eidolon helvum) sampled in 2009/10 in Ghana, for the presence of antibodies against the complete panel of influenza A haemagglutinin (HA) types ranging from H1 to H18 by means of a protein microarray platform. This technique enables simultaneous serological testing against multiple recombinant HA-types in 5μl of serum. Preliminary results indicate serological evidence against avian influenza subtype H9 in about 30% of the animals screened, with low-level cross-reactivity to phylogenetically closely related subtypes H8 and H12. To our knowledge, this is the first report of serological evidence of influenza A viruses other than H17 and H18 in bats. As avian influenza subtype H9 is associated with human infections, the implications of our findings from a public health context remain to be investigated.  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