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151.
Tingting Gu Jesper Just Katrine Tang Stenz Yan Yan Peter Sieljacks Jakob Wang Thomas Skjaerlund Groennebaek Jesper Emil Jakobsgaard Emil Rindom Jon Herskind Anders Gravholt Thomas Ravn Lassen Mathias Jrgensen Rikke Bk Eugenio Gutirrez-Jimnez Nina Kerting Iversen Peter Mondrup Rasmussen Jens Randel Nyengaard Malene Mller Jrgensen Frank de Paoli Hans Erik Btker Jrgen Kjems Kristian Vissing Kim Ryun Drasbek 《International journal of molecular sciences》2022,23(6)
Ischemic conditioning and exercise have been suggested for protecting against brain ischemia-reperfusion injury. However, the endogenous protective mechanisms stimulated by these interventions remain unclear. Here, in a comprehensive translational study, we investigated the protective role of extracellular vesicles (EVs) released after remote ischemic conditioning (RIC), blood flow restricted resistance exercise (BFRRE), or high-load resistance exercise (HLRE). Blood samples were collected from human participants before and at serial time points after intervention. RIC and BFRRE plasma EVs released early after stimulation improved viability of endothelial cells subjected to oxygen-glucose deprivation. Furthermore, post-RIC EVs accumulated in the ischemic area of a stroke mouse model, and a mean decrease in infarct volume was observed for post-RIC EVs, although not reaching statistical significance. Thus, circulating EVs induced by RIC and BFRRE can mediate protection, but the in vivo and translational effects of conditioned EVs require further experimental verification. 相似文献
152.
Hans Liew Stewart Mein Thomas Tessonnier Amir Abdollahi Jürgen Debus Ivana Dokic Andrea Mairani 《International journal of molecular sciences》2022,23(6)
The impact of the exact temporal pulse structure on the potential cell and tissue sparing of ultra-high dose-rate irradiation applied in FLASH studies has gained increasing attention. A previous version of our biophysical mechanistic model (UNIVERSE: UNIfied and VERSatile bio response Engine), based on the oxygen depletion hypothesis, has been extended in this work by considering oxygen-dependent damage fixation dynamics on the sub-milliseconds scale and introducing an explicit implementation of the temporal pulse structure. The model successfully reproduces in vitro experimental data on the fast kinetics of the oxygen effect in irradiated mammalian cells. The implemented changes result in a reduction in the assumed amount of oxygen depletion. Furthermore, its increase towards conventional dose-rates is parameterized based on experimental data from the literature. A recalculation of previous benchmarks shows that the model retains its predictive power, while the assumed amount of depleted oxygen approaches measured values. The updated UNIVERSE could be used to investigate the impact of different combinations of pulse structure parameters (e.g., dose per pulse, pulse frequency, number of pulses, etc.), thereby aiding the optimization of potential clinical application and the development of suitable accelerators. 相似文献
153.
Achim Mehlhorn Jürgen Fabian Siegfried Kulpe 《Advanced Synthesis \u0026amp; Catalysis》1984,326(2):303-310
Quantum Chemical Investigations of the Molecular and Electronic Structure of Simple Azomethine Imines and Related Compounds The molecular and electronic structure of simple azomethinimines are investigated by means of MINDO/3 and CNDO/2 calculations. The calculated molecular geometry is compared with X-ray results obtained for these compounds. Except for the NN-bond lengths MINDO/3 satisfactorily describes the molecular structure of azomethinimine and related π-electronic systems. The charges at the atoms along the conjugated chain are alternating as in polymethines. The terminal carbon atom carries a negative charge. This charge brings about an appreciable shielding of this carbon atom such as found in the 13C-n.m.r. spectrum. This result does not contradict a stabilization of azomethinimines in the crystal via = CH…︁OC interactions. 相似文献
154.
2-Aza-3-chloro-2-propeniminium salts 5 , which are easily available by the addition of formamide chlorides 1 to nitriles 2 react smoothly with hydrazines 9 giving rise to 1,3-disubstituted 1,2,4,-triazoles 11 . When the 2-aza-3-chloro-2-propeniminium salts 5 are hydrolysed first the resulting N-acyl-formamidinium salts 6 react with hydrazines 9 to 1,5 disubstituted 1,2,4-triazoles 13 via isolable N-acyl-formamidrazones 12 . 相似文献
155.
George Makrides Bastian Zinsser Matthew Norton George E. Georghiou Markus Schubert Jürgen H. Werner 《Renewable & Sustainable Energy Reviews》2010,14(2):754-762
Renewable energy sources derived principally from solar energy have been gaining ground over the last few years and are now beginning to contribute to the global energy mix. Solar energy in the form of direct electricity conversion (photovoltaics) is already very popular in countries such as the United States, Germany and Japan. The enormous potential of photovoltaic (PV) technology is also obvious and favourable in countries with high irradiation such as the Mediterranean region. The objective of this paper is to review the different up and coming PV technologies, to explore the potential of different PV systems in countries with high solar irradiation and to compare their performance through the assessment of thirteen different types of PV systems that have been installed side by side in Nicosia, Cyprus and Stuttgart, Germany. Finally useful insight into the performance of the PV systems as a function of the meteorological conditions and location will be highlighted. 相似文献
156.
Testing of carbon supported Pd-Pt electrocatalysts for methanol electrooxidation in direct methanol fuel cells 总被引:1,自引:0,他引:1
Francisco Alcaide Garbiñe ÁlvarezPere L. Cabot Hans-Jürgen GrandeOscar Miguel Amaia Querejeta 《International Journal of Hydrogen Energy》2011,36(7):4432-4439
In the present work, a detailed characterization of the electrochemical behavior of carbon supported Pd-Pt electrocatalysts toward CO and methanol electrooxidation in direct methanol fuel cells is reported. Technical electrodes containing an ionomer in their catalyst layer were prepared for this purpose. CO and methanol electrooxidation reactions were used as test reactions to compare the electrocatalytic behavior of bimetallic supported nanoparticles in acidic liquid electrolyte and in solid polymer electrolyte (real fuel cell operating conditions). Experimental results in both environments are consistent and show that the electrochemical behavior of carbon supported Pd-Pt depends on their composition, giving the best performance in direct methanol single fuel cell with a Pd:Pt atomic ratio of 25:75 in the catalyst. 相似文献
157.
Kasper T. Møller Mathias Jørgensen Jacob G. Andreasen Jørgen Skibsted Zbigniew Łodziana Yaroslav Filinchuk Torben R. Jensen 《International Journal of Hydrogen Energy》2018,43(1):311-321
A new potassium tetraamidoboranealuminate, K[Al(NH2BH3)4], has been synthesized by a mechanochemical reaction between KAlH4 and NH3BH3. The compound, K[Al(NH2BH3)4], crystallizes in a triclinic unit cell with space group symmetry P?1. The crystal structure consists of [K(NH2BH3)6]5? octahedra which facilitate the bridging between K+ in 1D chains, while also bridging K+ to Al3+ to connect the 1D chains in a 3D network. Thermal analysis reveals that K[Al(NH2BH3)4] decomposes in two exothermic steps at T ~ 94 and 138 °C and releases primarily hydrogen. The total gas release amounts to ~6.0 wt% H2. The decomposition products are investigated ex situ by powder X-ray diffraction, infrared spectroscopy, and 11B and 27Al NMR and identified as KBH4 and amorphous phases, possibly BN3, N2BH, and/or NBH2 whereas aluminum is found in four-, five-, and six-fold coordination. Unfortunately, the decomposed sample shows no hydrogen absorption at T = 260 °C and p(H2) = 110 bar. 相似文献
158.
Industrial production systems and industrially manufactured products are constantly evolving due to technical innovations and customers’ demands. Therefore, ensuring an optimized co-evolution of both becomes an important yet challenging task. Approaches for model-based systems engineering have been widely investigated and have already had significant impact on industrial practice. However, existing model-based approaches mostly are focusing on particular aspects of a production system and do not provide a holistic approach for optimizing automated production systems, their deployment, and their co-evolution with the product. As a first step towards this direction, this contribution proposes the combination of an engineering approach for aPS based on systems modeling language with models and techniques for deployment of software and hardware to cyber-physical system architectures, which have been investigated in the field of computer science, and motivates the possibilities of a combined approach. 相似文献
159.
Power generation from renewable energy sources and fossil fuels are integrated into one system. A combination of technologies in the form of a carbon capture utilization (CCU)-combined power station is proposed. The technology is based on energy generation from fossil fuels by a coal power plant with CO2 recovery from exhaust gases, and pyrolysis of natural gas to hydrogen and carbon, completed by reverse water-gas shift for the conversion of CO2 to CO, which will react with hydrogen in a Fischer-Tropsch synthesis for synthetic diesel. The carbon from the pyrolysis can replace other fossil carbon or can be sequestered. This technology offers significant CO2 savings compared to the current state of technology and makes an environmentally friendly use of fossil fuels for electricity and fuel sectors possible. 相似文献
160.
Nicole Jacqueline Jensen Helena Zander Wodschow Malin Nilsson Jrgen Rungby 《International journal of molecular sciences》2020,21(22)
Under normal physiological conditions the brain primarily utilizes glucose for ATP generation. However, in situations where glucose is sparse, e.g., during prolonged fasting, ketone bodies become an important energy source for the brain. The brain’s utilization of ketones seems to depend mainly on the concentration in the blood, thus many dietary approaches such as ketogenic diets, ingestion of ketogenic medium-chain fatty acids or exogenous ketones, facilitate significant changes in the brain’s metabolism. Therefore, these approaches may ameliorate the energy crisis in neurodegenerative diseases, which are characterized by a deterioration of the brain’s glucose metabolism, providing a therapeutic advantage in these diseases. Most clinical studies examining the neuroprotective role of ketone bodies have been conducted in patients with Alzheimer’s disease, where brain imaging studies support the notion of enhancing brain energy metabolism with ketones. Likewise, a few studies show modest functional improvements in patients with Parkinson’s disease and cognitive benefits in patients with—or at risk of—Alzheimer’s disease after ketogenic interventions. Here, we summarize current knowledge on how ketogenic interventions support brain metabolism and discuss the therapeutic role of ketones in neurodegenerative disease, emphasizing clinical data. 相似文献