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排序方式: 共有63条查询结果,搜索用时 22 毫秒
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Paula H Suss Luiz Guilherme A Capriglione Fabiane Barchiki Lye Miyague Danielle Jackowski Letícia Fracaro Andressa V Schittini Alexandra C Senegaglia Carmen LK Rebelatto Márcia Olandoski Alejandro Correa Paulo RS Brofman 《Experimental biology and medicine (Maywood, N.J.)》2015,240(7):969-978
The development of new therapeutic strategies is necessary to reduce the worldwide social and economic impact of cardiovascular disease, which produces high rates of morbidity and mortality. A therapeutic option that has emerged in the last decade is cell therapy. The aim of this study was to compare the effect of transplanting human umbilical cord-derived stromal cells (UCSCs), human umbilical cord blood-derived endothelial cells (UCBECs) or a combination of these two cell types for the treatment of ischemic cardiomyopathy (IC) in a Wistar rat model. IC was induced by left coronary artery ligation, and baseline echocardiography was performed seven days later. Animals with a left ventricular ejection fraction (LVEF) of ≤40% were selected for the study. On the ninth day after IC was induced, the animals were randomized into the following experimental groups: UCSCs, UCBECs, UCSCs plus UCBECs, or vehicle (control). Thirty days after treatment, an echocardiographic analysis was performed, followed by euthanasia. The animals in all of the cell therapy groups, regardless of the cell type transplanted, had less collagen deposition in their heart tissue and demonstrated a significant improvement in myocardial function after IC. Furthermore, there was a trend of increasing numbers of blood vessels in the infarcted area. The median value of LVEF increased by 7.19% to 11.77%, whereas the control group decreased by 0.24%. These results suggest that UCSCs and UCBECs are promising cells for cellular cardiomyoplasty and can be an effective therapy for improving cardiac function following IC. 相似文献
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High level of divergence of male-reproductive-tract proteins, between Drosophila melanogaster and its sibling species, D. simulans 总被引:1,自引:0,他引:1
We compared male-reproductive-tract polypeptides of Drosophila melanogaster
and D. simulans by using two-dimensional gel electrophoresis. Approximately
64% of male-reproductive-tract polypeptides were identical between two
randomly chosen isofemale lines from these two species, compared with 83%
identity for third-instar imaginal wing-disc polypeptides. Qualitatively
similar differences were found between reproductive tracts and imaginal
discs when D. sechellia was compared with D. melanogaster and with D.
simulans. When genic polymorphism was taken into account, approximately 10%
of male- reproductive-tract polypeptides were apparently fixed for
different alleles between D. melanogaster and D. simulans; this proportion
is the same as that found for soluble enzymes by one-dimensional gel
electrophoresis. Strikingly, approximately 20% of male-reproductive- tract
polypeptides of either D. melanogaster or D. simulans had no detectable
homologue in the other species. We propose that proteins of the Drosophila
male reproductive tract may have diverged more extensively between species
than have other types of proteins and that much of this divergence may
involve large changes in levels of polypeptide expression.
相似文献
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Patients with systemic autoimmune diseases usually produce high levels of antibodies to self-antigens (autoantigens). The
repertoire of common autoantigens is remarkably limited, yet no readily understandable shared thread links these apparently
diverse proteins. Using computer prediction algorithms, we have found that most nuclear systemic autoantigens are predicted
to contain long regions of extreme structural disorder. Such disordered regions would generally make poor B cell epitopes
and are predicted to be under-represented as potential T cell epitopes. Consideration of the potential role of protein disorder
may give novel insights into the possible role of molecular mimicry in the pathogenesis of autoimmunity. The recognition of
extreme autoantigen protein disorder has led us to an explicit model of epitope spreading that explains many of the paradoxical
aspects of autoimmunity – in particular, the difficulty in identifying autoantigen-specific helper T cells that might collaborate
with the B cells activated in systemic autoimmunity. The model also explains the experimentally observed breakdown of major
histocompatibility complex (MHC) class specificity in peptides associated with the MHC II proteins of activated autoimmune
B cells, and sheds light on the selection of particular T cell epitopes in autoimmunity. Finally, the model helps to rationalize
the relative rarity of clinically significant autoimmunity despite the prevalence of low specificity/low avidity autoantibodies
in normal individuals. 相似文献
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RS Fisher 《The Journal of general physiology》1977,69(5):571-604
When the outer surface of short-circuited frog skin was penetrated with microelectrodes, stable negative potentials that averaged near -100 mV were recorded consistently, confirming the results of Nagel (W. Nagel. 1975. Abstracts of the 5th International Biophysics Congress, Copenhagen. P-147.). The appearance of these stable potentials, V(O), concurrent with the observations that (a) a high resistance outer barrier R(O) accounting for approximately 75 percent or more of the transcellular resistance of control skins had been penetrated and that (b) 10(-5) M amiloride and reduced [Na] outside caused the values of V(O) to increase towards means value near -130 mV while the values of percent R(O) increased to more than 90 percent. It was of relationships were the same as the values of E(1) observed in studies of the current-voltage relationships were the same as the values of E’(1) defined as the values of voltage at the inner barrier when the V(O) of the outer barrier was reduced to zero by voltage clamping of the skins. Accordingly, these data are interpreted to mean that the values of E(1), approximately 130 mV, represent the E(Na) of the sodium pump at the inner barrier. 2,4-DNP was observed to decrease the values of transepithelial voltage less than E(1) the V(O) was negative. These data can be interpreted with a simple electrical equivalent circuit of the active sodium transport pathway of the frog skin that includes the idea that the outer membrane behaves as an electrical rectifier for ion transport. 相似文献
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Adluri RS Thirunavukkarasu M Zhan L Dunna NR Akita Y Selvaraju V Otani H Sanchez JA Ho YS Maulik N 《PloS one》2012,7(3):e34790
Oxidative stress plays a critical role in the pathophysiology of cardiac failure, including the modulation of neovascularization following myocardial infarction (MI). Redox molecules thioredoxin (Trx) and glutaredoxin (Grx) superfamilies actively maintain intracellular thiol-redox homeostasis by scavenging reactive oxygen species. Among these two superfamilies, the pro-angiogenic function of Trx-1 has been reported in chronic MI model whereas similar role of Grx-1 remains uncertain. The present study attempts to establish the role of Grx-1 in neovascularization and ventricular remodeling following MI. Wild-type (WT) and Grx-1 transgenic (Grx-1(Tg/+)) mice were randomized into wild-type sham (WTS), Grx-1(Tg/+) Sham (Grx-1(Tg/+)S), WTMI, Grx-1(Tg/+)MI. MI was induced by permanent occlusion of the LAD coronary artery. Sham groups underwent identical time-matched surgical procedures without LAD ligation. Significant increase in arteriolar density was observed 7 days (d) after surgical intervention in the Grx-1(Tg/+)MI group as compared to the WTMI animals. Further, improvement in myocardial functional parameters 30 d after MI was observed including decreased LVIDs, LVIDd, increased ejection fraction and, fractional shortening was also observed in the Grx-1(Tg/+)MI group as compared to the WTMI animals. Moreover, attenuation of oxidative stress and apoptotic cardiomyocytes was observed in the Grx-1(Tg/+)MI group as compared to the WTMI animals. Increased expression of p-Akt, VEGF, Ang-1, Bcl-2, survivin and DNA binding activity of NF-κB were observed in the Grx-1(Tg/+)MI group when compared to WTMI animals as revealed by Western blot analysis and Gel-shift analysis, respectively. These results are the first to demonstrate that Grx-1 induces angiogenesis and diminishes ventricular remodeling apparently through neovascularization mediated by Akt, VEGF, Ang-1 and NF-κB as well as Bcl-2 and survivin-mediated anti-apoptotic pathway in the infarcted myocardium. 相似文献
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EFFECTS OF HUMAN ACTIVITIES ON STRUCTURE AND COMPOSITION OF WOODY SPECIES OF THE NOKREK BIOSPHERE RESERVE OF MEGHALAYA,NORTHEAST INDIA 下载免费PDF全文
Aims Our study was conducted in the Nokrek Biosphere Reserve (NBR) in the Garo hills districts of Meghalaya, Northeast India. Our aim was to assess the effects of human activities on plant diversity,population structure and regeneration.Methods We selected a representative 1.2 hm2 stand in both the core and buffer zones of NBR. Structure and composition were determined by randomly sampling square quadrats, population structure was assessed by determining age structure, and regeneration was assessed by measuring densities of seedling, sapling and adult trees.Important findings More woody species were recorded from the core zone than the buffer zone (87 vs. 81 species), and there were a large number of tropical, temperate, and Sino-Himalayan, Burma-Malaysian and Malayan elements, primitive families and primitive genera. The trees were distributed in three distinct strata,canopy, subcanopy and sapling. Subcanopy and sapling layers had the highest species richness (81% -88% ). Lauraceae and Euphorbiaceae were the dominant families in terms of the number of species, and a large number of families were represented by single species. Most woody species (57 % - 79 % ) were contagiously distributed and had low frequency ( < 20% ). Although stand density was high in the buffer zone, its basal area was low compared to the stand in the core zone. Low similarity and high β-diversity indicate marked differences in species composition of the stands. Shannon diversity index was high in both the stands, while Simpson dominance index was low. The diameter-class distribution for dominant species revealed that the most had a large number of young individuals in their populations. Preponderance of tree seedlings, followed by a steep decline in population density of saplings and adult trees, indicated that the seedling to sapling stage was the most critical in the life cycle of the tree populations. Most species (42 % - 48 % ) had no regeneration,25 % - 35 % had good/fair regeneration, and the rest had poor regeneration or reoccurred as immigrants. 相似文献
8.
Thirunavukkarasu M Adluri RS Juhasz B Samuel SM Zhan L Kaur A Maulik G Sanchez JA Hager J Maulik N 《Functional & integrative genomics》2012,12(3):501-514
Several potential sources of reactive oxygen species (ROS) in cells exist. One source is NADPH oxidase, which is especially important for superoxide radical production. Nox2 is a primary regulatory subunit of NADPH oxidase. In the present study, we examined the role of ROS and NADPH oxidase in ischemic preconditioning (IP)-mediated cardioprotection by using Nox2(-/-) mice. Both wild-type (WT) and Nox2(-/-) mice were subjected to either 30?min of ischemia followed by 2?h of reperfusion (IR) or IP prior to 30?min ischemia and 2?h of reperfusion. Reduction in left ventricular developed pressure (60.1 versus 63?mmHg), dp/dt (max) (893 versus 1,027?mmHg/s), and aortic flow (0.9 versus 1.8?ml/min) was observed in Nox2(-/-)IPIR compared to WTIPIR along with increased infarct size (33% versus 22%) and apoptosis after 120?min of reperfusion. Differentially regulated genes were demonstrated by comparing gene expression in WTIPIR versus Nox2(-/-) IPIR hearts. Selected differentially regulated genes such as β-catenin, SRPK3, ERDR1, ACIN1, Syntaxin-8, and STC1 were validated by real-time PCR. Taken together, this is the first report identifying important, differentially expressed genes during ischemic preconditioning in Nox2(-/-) mice by using microarray analysis. 相似文献
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