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141.
Suppression of inflammation by a synthetic histone mimic 总被引:1,自引:0,他引:1
Nicodeme E Jeffrey KL Schaefer U Beinke S Dewell S Chung CW Chandwani R Marazzi I Wilson P Coste H White J Kirilovsky J Rice CM Lora JM Prinjha RK Lee K Tarakhovsky A 《Nature》2010,468(7327):1119-1123
142.
Sugar transporters for intercellular exchange and nutrition of pathogens 总被引:10,自引:0,他引:10
Chen LQ Hou BH Lalonde S Takanaga H Hartung ML Qu XQ Guo WJ Kim JG Underwood W Chaudhuri B Chermak D Antony G White FF Somerville SC Mudgett MB Frommer WB 《Nature》2010,468(7323):527-532
Sugar efflux transporters are essential for the maintenance of animal blood glucose levels, plant nectar production, and plant seed and pollen development. Despite broad biological importance, the identity of sugar efflux transporters has remained elusive. Using optical glucose sensors, we identified a new class of sugar transporters, named SWEETs, and show that at least six out of seventeen Arabidopsis, two out of over twenty rice and two out of seven homologues in Caenorhabditis elegans, and the single copy human protein, mediate glucose transport. Arabidopsis SWEET8 is essential for pollen viability, and the rice homologues SWEET11 and SWEET14 are specifically exploited by bacterial pathogens for virulence by means of direct binding of a bacterial effector to the SWEET promoter. Bacterial symbionts and fungal and bacterial pathogens induce the expression of different SWEET genes, indicating that the sugar efflux function of SWEET transporters is probably targeted by pathogens and symbionts for nutritional gain. The metazoan homologues may be involved in sugar efflux from intestinal, liver, epididymis and mammary cells. 相似文献
143.
Human ES-cell-derived cardiomyocytes electrically couple and suppress arrhythmias in injured hearts 总被引:1,自引:0,他引:1
Y Shiba S Fernandes WZ Zhu D Filice V Muskheli J Kim NJ Palpant J Gantz KW Moyes H Reinecke B Van Biber T Dardas JL Mignone A Izawa R Hanna M Viswanathan JD Gold MI Kotlikoff N Sarvazyan MW Kay CE Murry MA Laflamme 《Nature》2012,489(7415):322-325
Transplantation studies in mice and rats have shown that human embryonic-stem-cell-derived cardiomyocytes (hESC-CMs) can improve the function of infarcted hearts, but two critical issues related to their electrophysiological behaviour in vivo remain unresolved. First, the risk of arrhythmias following hESC-CM transplantation in injured hearts has not been determined. Second, the electromechanical integration of hESC-CMs in injured hearts has not been demonstrated, so it is unclear whether these cells improve contractile function directly through addition of new force-generating units. Here we use a guinea-pig model to show that hESC-CM grafts in injured hearts protect against arrhythmias and can contract synchronously with host muscle. Injured hearts with hESC-CM grafts show improved mechanical function and a significantly reduced incidence of both spontaneous and induced ventricular tachycardia. To assess the activity of hESC-CM grafts in vivo, we transplanted hESC-CMs expressing the genetically encoded calcium sensor, GCaMP3 (refs 4, 5). By correlating the GCaMP3 fluorescent signal with the host ECG, we found that grafts in uninjured hearts have consistent 1:1 host–graft coupling. Grafts in injured hearts are more heterogeneous and typically include both coupled and uncoupled regions. Thus, human myocardial grafts meet physiological criteria for true heart regeneration, providing support for the continued development of hESC-based cardiac therapies for both mechanical and electrical repair. 相似文献
144.
Increase in observed net carbon dioxide uptake by land and oceans during the past 50 years 总被引:3,自引:0,他引:3
One of the greatest sources of uncertainty for future climate predictions is the response of the global carbon cycle to climate change. Although approximately one-half of total CO(2) emissions is at present taken up by combined land and ocean carbon reservoirs, models predict a decline in future carbon uptake by these reservoirs, resulting in a positive carbon-climate feedback. Several recent studies suggest that rates of carbon uptake by the land and ocean have remained constant or declined in recent decades. Other work, however, has called into question the reported decline. Here we use global-scale atmospheric CO(2) measurements, CO(2) emission inventories and their full range of uncertainties to calculate changes in global CO(2) sources and sinks during the past 50 years. Our mass balance analysis shows that net global carbon uptake has increased significantly by about 0.05 billion tonnes of carbon per year and that global carbon uptake doubled, from 2.4?±?0.8 to 5.0?±?0.9 billion tonnes per year, between 1960 and 2010. Therefore, it is very unlikely that both land and ocean carbon sinks have decreased on a global scale. Since 1959, approximately 350 billion tonnes of carbon have been emitted by humans to the atmosphere, of which about 55 per cent has moved into the land and oceans. Thus, identifying the mechanisms and locations responsible for increasing global carbon uptake remains a critical challenge in constraining the modern global carbon budget and predicting future carbon-climate interactions. 相似文献
145.
Research over the past 25 years has led to the view that the rich tapestry of present-day cosmic structure arose during the first instants of creation, where weak ripples were imposed on the otherwise uniform and rapidly expanding primordial soup. Over 14 billion years of evolution, these ripples have been amplified to enormous proportions by gravitational forces, producing ever-growing concentrations of dark matter in which ordinary gases cool, condense and fragment to make galaxies. This process can be faithfully mimicked in large computer simulations, and tested by observations that probe the history of the Universe starting from just 400,000 years after the Big Bang. 相似文献
146.
W Born C Miles J White R O'Brien J H Freed P Marrack J Kappler R T Kubo 《Nature》1987,330(6148):572-574
Although most mature peripheral T lymphocytes express a major histocompatibility complex restricted, CD3-associated, antigen receptor (TCR) which has been well characterized, some T cells carry a different CD3-associated heterodimer on their surface. One of the two disulphide-linked chains of this putative second receptor, which in mice has relative molecular mass (Mr) 35,000 (35K), has been identified as a product of the group of gamma genes. The other chain, termed delta (Mr 45K in mice), is not as well characterized. Although gamma/delta-bearing cells are a minor subset among peripheral T lymphocytes, they are the only CD3+ cells in the thymus early in ontogeny. Taking advantage of these kinetics, we have generated gamma/delta-bearing hybridomas, using a new TCR alpha chain-negative variant of the AKR thymoma BW5147 as tumour parent, fetal thymocytes as normal cell partners, and an anti-CD3 monoclonal antibody (mAb) as screening reagent. Gamma and delta chains from one of these hybrids have been purified and partially sequenced. The sequences obtained indicate that delta is indeed identical to the polypeptide encoded by the recently described gene X, as suggested by Chien et al. 相似文献
147.
The paper reports results of an experiment conducted to evaluate subjective versus objective combination of forecasts. The subjects were undergraduate students at Texas A&M. The students forecasted two different types of time series. The results found show that the subjective combination of forecasts improves their accuracy as compared with individual efforts. Four ex-ante weighting methods were also used to combine the forecasts. They all improve the accuracy of the forecasts. The best results, though, were from the subjective combination of forecasts. 相似文献
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150.
T. White 《Cellular and molecular life sciences : CMLS》1963,19(1):43-44
Zusammenfassung In narkotisierte Katzen wurde C14-Histamin entweder durch Hirnventrikel perfundiert oder intravenös injiziert. Seine Ausscheidung und Metabolite in Urin wurde gleichzeitig bestimmt: Ca. 2% des durch die Hirnventrikel perfundierten C14-Histamins wurde im Blutstrom resorbiert. 相似文献