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871.
We report on the development of a new environmental simulation chamber coupled with an in situ continuous wave cavity ring-down spectrometer operating in the near IR (~1.5 μm). The first application reported in this paper dealt with the chemical mechanism of UV photolysis of methyl nitrite (CH(3)ONO) in air. HONO has been detected for the first time and shown to be formed in the OH + CH(3)ONO reaction. A dense spectrum of cis-HONO absorption lines has been observed near 1.5 μm, in agreement with a previous study (Guilmot et al.). CH(2)O has been measured as primary product with good sensitivity and time resolution. In contrast to Zhao et al., we did not detect any NO(2) absorption features in this wavelength range. Calibration experiments provided very low NO(2) absorption cross sections in this region (~10(-25) cm(2)), leading to conclude that NO(2) cannot be observed in this wavelength range in the presence of equal amounts of CH(2)O. 相似文献
872.
Corinna Schilling Thomas Mack Selene Lickfett Stefanie Sieste Francesco S. Ruggeri Tomas Sneideris Arghya Dutta Tristan Bereau Ramin Naraghi Daniela Sinske Tuomas P. J. Knowles Christopher V. Synatschke Tanja Weil Bernd Knll 《Advanced functional materials》2019,29(24)
There is an urgent need for biomaterials that support tissue healing, particularly neuronal regeneration. In a medium throughput screen novel self‐assembling peptide (SAP) sequences that form fibrils and stimulated nerve fiber growth of peripheral nervous system (PNS)‐derived neurons are identified. Based on the peptide sequences and fibril morphologies and by applying rational data‐mining, important structural parameters stimulating neuronal activity are elucidated. Three SAPs (SAP1e, SAP2e, and SAP5c) enhance adhesion and growth of PNS neurons. These SAPs form 2D and 3D matrices that serve as bioactive scaffolds stimulating cell adhesion and growth. The newly discovered SAPs also support the growth of CNS neurons and glia cells. Subsequently, the potential of SAPs to enhance PNS regeneration in vivo is analyzed. For this, the facial nerve driving whisker movement in mice is injured. Notably, SAPs persist for up to 3 weeks in the injury site indicating highly adhesive properties and stability. After SAP administration, more motor neurons incorporating markers for successive regeneration are observed. Recovery of whisker movement is elevated in SAP‐injected mice. In summary, short peptides that form fibrils are identified and the adhesion, growth, and regeneration of neurons have been efficiently enhanced without the necessity to attach hormones or growth factors. 相似文献
873.
Klein A Sauer T Jedynak A Skrandies W 《IEEE transactions on bio-medical engineering》2006,53(2):266-272
The use of coherence is a well-established standard approach for the analysis of biomedical signals. Being entirely based on frequency analysis, i.e., on spectral properties of the signal, it is not possible to obtain any information about the temporal structure of coherence which is useful in the study of brain dynamics, for example. Extending the concept of coherence as a measure of linear dependence between realizations of a random process to the wavelet transform, this paper introduces a new approach to coherence analysis which allows to monitor time-dependent changes in the coherence between electroenecphalographic (EEG) channels. Specifically, we analyzed multichannel EEG data of 26 subjects obtained in an experiment on associative learning, and compare the results of Fourier coherence and wavelet coherence, showing that wavelet coherence detects features that were inaccessible by application of Fourier coherence. 相似文献
874.
Tomas Bolumar Vibeke Orlien Anita Sikes Kemal Aganovic Kathrine H. Bak Claire Guyon Anna-Sophie Stübler Marie de Lamballerie Christian Hertel Dagmar A. Brüggemann 《Comprehensive Reviews in Food Science and Food Safety》2021,20(1):332-368
High-pressure processing (HPP) has been the most adopted nonthermal processing technology in the food industry with a current ever-growing implementation, and meat products represent about a quarter of the HPP foods. The intensive research conducted in the last decades has described the molecular impacts of HPP on microorganisms and endogenous meat components such as structural proteins, enzyme activities, myoglobin and meat color chemistry, and lipids, resulting in the characterization of the mechanisms responsible for most of the texture, color, and oxidative changes observed when meat is submitted to HPP. These molecular mechanisms with major effect on the safety and quality of muscle foods are comprehensively reviewed. The understanding of the high pressure–induced molecular impacts has permitted a directed use of the HPP technology, and nowadays, HPP is applied as a cold pasteurization method to inactive vegetative spoilage and pathogenic microorganisms in ready-to-eat cold cuts and to extend shelf life, allowing the reduction of food waste and the gain of market boundaries in a globalized economy. Yet, other applications of HPP have been explored in detail, namely, its use for meat tenderization and for structure formation in the manufacturing of processed meats, though these two practices have scarcely been taken up by industry. This review condenses the most pertinent-related knowledge that can unlock the utilization of these two mainstream transformation processes of meat and facilitate the development of healthier clean label processed meats and a rapid method for achieving sous vide tenderness. Finally, scientific and technological challenges still to be overcome are discussed in order to leverage the development of innovative applications using HPP technology for the future meat industry. 相似文献
875.
Dag Johansen P?l Halvorsen H?vard Johansen H?kon Riiser Cathal Gurrin Bj?rn Olstad Carsten Griwodz ?ge Kvalnes Joseph Hurley Tomas Kupka 《Multimedia Tools and Applications》2012,61(2):419-445
Locating content in existing video archives is both a time and bandwidth consuming process since users might have to download and manually watch large portions of superfluous videos. In this paper, we present two novel prototypes using an Internet based video composition and streaming system with a keyword-based search interface that collects, converts, analyses, indexes, and ranks video content. At user requests, the system can automatically sequence out portions of single videos or aggregate content from multiple videos to produce a single, personalized video stream on-the-fly. 相似文献
876.
Cache memories represent a core topic in all computer organization and architecture courses offered at universities around the world. As a consequence, educational proposals and textbooks address important efforts to this topic. A valuable pedagogical help when studying cache memories is to perform exercises based on simple algorithms, which allow the identification of cache accesses, for instance, a program accessing the elements of an array. These exercises, referred to as code-based exercises, have a good acceptance among instructors of computer organization courses. Nevertheless, no tool (e.g., simulator) has been developed to be used in undergraduate courses working with this kind of exercises; therefore, students perform such exercises by means of the classic paper and pencil methodology. To fill this gap, this paper proposes a new pedagogical tool, namely Spim-cache. A laboratory example is also presented for illustrative purposes. 相似文献
877.
878.
Barbara Sivakova Jan Jurcik Veronika Lukacova Tomas Selicky Ingrid Cipakova Peter Barath Lubos Cipak 《International journal of molecular sciences》2021,22(4)
The phosphorylation of proteins modulates various functions of proteins and plays an important role in the regulation of cell signaling. In recent years, label-free quantitative (LFQ) phosphoproteomics has become a powerful tool to analyze the phosphorylation of proteins within complex samples. Despite the great progress, the studies of protein phosphorylation are still limited in throughput, robustness, and reproducibility, hampering analyses that involve multiple perturbations, such as those needed to follow the dynamics of phosphoproteomes. To address these challenges, we introduce here the LFQ phosphoproteomics workflow that is based on Fe-IMAC phosphopeptide enrichment followed by strong anion exchange (SAX) and porous graphitic carbon (PGC) fractionation strategies. We applied this workflow to analyze the whole-cell phosphoproteome of the fission yeast Schizosaccharomyces pombe. Using this strategy, we identified 8353 phosphosites from which 1274 were newly identified. This provides a significant addition to the S. pombe phosphoproteome. The results of our study highlight that combining of PGC and SAX fractionation strategies substantially increases the robustness and specificity of LFQ phosphoproteomics. Overall, the presented LFQ phosphoproteomics workflow opens the door for studies that would get better insight into the complexity of the protein kinase functions of the fission yeast S. pombe. 相似文献
879.
880.
Francisco Manuel Baena‐Moreno Mnica Rodríguez‐Galn Fernando Vega Tomas Ramirez‐Reina Luis Vilches Benito Navarrete 《国际能源研究杂志》2019,43(4):1578-1585
This paper reveals a regeneration method for a carbonate compound after carbon dioxide (CO2) absorption in a biogas upgrading unit run with caustic mixtures, obtaining precipitated calcium carbonate (PCC) as valuable by‐product. This process arises as an alternative to physical regeneration, which is highly energy intensive. This work provides novel insights on the regeneration efficiency of carbonates to hydroxides while also studying the influence of K+ or Na+ in the caustic CO2‐trapping solution. The compared parameters were the reaction time, temperature, and molar ratio. Moreover, psychochemical characterization of solids was obtained by means of Fourier‐transform infrared spectroscopy (FTIR), Raman spectroscopy, X‐ray powder diffraction (XRD), and scanning electron microscopy (SEM) images. The results indicate that regeneration efficiencies are slightly lower when potassium is used instead of sodium, but quite acceptable for both of them. The chemical characterization experiments showed the predominance of calcium carbonate. Overall, the results obtained in this study proved that this process is feasible to upgrade biogas through PCC precipitation, which appears to be a promising economically viable process to synergize carbon capture and storage (CCS) and carbon capture and utilization (CCU). 相似文献