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11.
This study focuses on the determination and concentration of twelve elements (Na, K, Ca, Mg, Cr, Mn, Fe, Co, Ni, Cu, Zn and Cd) occurring in sub-bituminous Assam coals and their geochemical association. Distribution of these elements between organic and mineral matters was studied. Comparison of the results of three coals has shown that three elements (Mg, Ca and Mn) are significantly organic bound, while five elements (Fe, Co, Ni, Cu and Zn) are significantly mineral bound; Cd is 50% bound to either organic or mineral matter. FTIR and XRD studies reveal qualitative information about the bonding pattern and nature of components of the mineral matters. The results obtained in this study have considerable geochemical and technological interests. 相似文献
12.
One Question,Multiple Answers: Biochemical and Biophysical Screening Methods Retrieve Deviating Fragment Hit Lists 下载免费PDF全文
Dr. Johannes Schiebel Nedyalka Radeva Dr. Helene Köster Dr. Alexander Metz Timo Krotzky Dr. Maren Kuhnert Prof. Wibke E. Diederich Prof. Andreas Heine Dr. Lars Neumann Dr. Cedric Atmanene Dominique Roecklin Dr. Valérie Vivat‐Hannah Dr. Jean‐Paul Renaud Dr. Robert Meinecke Dr. Nina Schlinck Dr. Astrid Sitte Franziska Popp Dr. Markus Zeeb Prof. Gerhard Klebe 《ChemMedChem》2015,10(9):1511-1521
Fragment‐based lead discovery is gaining momentum in drug development. Typically, a hierarchical cascade of several screening techniques is consulted to identify fragment hits which are then analyzed by crystallography. Because crystal structures with bound fragments are essential for the subsequent hit‐to‐lead‐to‐drug optimization, the screening process should distinguish reliably between binders and non‐binders. We therefore investigated whether different screening methods would reveal similar collections of putative binders. First we used a biochemical assay to identify fragments that bind to endothiapepsin, a surrogate for disease‐relevant aspartic proteases. In a comprehensive screening approach, we then evaluated our 361‐entry library by using a reporter‐displacement assay, saturation‐transfer difference NMR, native mass spectrometry, thermophoresis, and a thermal shift assay. While the combined results of these screening methods retrieve 10 of the 11 crystal structures originally predicted by the biochemical assay, the mutual overlap of individual hit lists is surprisingly low, highlighting that each technique operates on different biophysical principles and conditions. 相似文献
13.
14.
Supersonic nozzles have been applied in various jet‐induced fluidised bed attrition processes such as jet milling and Fluid Coking. In jet‐induced particle attrition, the penetration length into the bed of the jet issuing from the supersonic nozzle is a critical property that affects the attrition mechanisms. A numerical model was developed to predict the penetration length of jets issuing from a horizontal supersonic nozzle in high temperature fluidised beds, based on an Eulerian–Eulerian multiphase model and Granular kinetic theory. The predicted jet penetration lengths are in very good agreement with the experimental data and the predictions of Li's empirical correlation [Li, “Penetration of High Velocity Horizontal Gas Jets Into a Fluidized Bed at High Temperature”, in Fluidization XIII, S. D. Kim, Y. Kang, J. K. Lee, Y. C. Seo, Eds., Gyeong‐ju, Korea 2010 ; Engineering Conferences International, Gyeong‐ju, Korea 2010 , pp. 893–900.]. The simulation results have also demonstrated that the fluidisation velocity and bed temperature have little influence on jet penetration length. © 2013 Canadian Society for Chemical Engineering 相似文献
15.
The synthesis of graft copolymers by the grafting “onto” process in the molten state was described. Functional oligomers obtained by telomerization or by ATRP were reacted onto maleic anhydride grafted polypropylene (PP-g-MAH) and poly(ethylene-ter-maleic anhydride-ter-methyl acrylate) (P(E-ter-MAH-ter-MeA)) to obtain PP-g-PMMA and P(E-ter-MAH-ter-MeA)-g-PMMA graft copolymers, respectively. The grafting of different mono-functional oligomers bearing hydroxyl, aliphatic amine or aromatic amine functions was investigated at 180 °C and at 200 °C. The grafting efficiency was very low in the case of hydroxyl-terminated PMMA, while the amine-terminated PMMA led to high yields. In the last part, PP-g-PMMA and P(E-ter-MAH-ter-MeA)-g-PMMA graft copolymers were synthesized by the reaction of aliphatic amine functional PMMA oligomers onto PP-g-MAH and P(E-ter-MAH-ter-MeA), respectively. The influence of the molecular weight of PMMA oligomers was investigated and showed that he grafting efficiency slightly decreases with the increasing molecular weight. However, this process allows the synthesis of PP-g-PMMA graft copolymers containing 6-45 wt% of PMMA side chains. The microstructure of the nanostructured PP-g-PMMA and P(E-ter-MAH-ter-MeA)-g-PMMA graft copolymers was investigated by TEM and SEM. This was established that the addition of PP-g-PMMA in PP/PMMA binary blends allows to control their morphologies and stabilities. 相似文献
16.
Didem Ag Seleci Viktor Maurer Firat Baris Barlas Julian Cedric Porsiel Bilal Temel Elcin Ceylan Suna Timur Frank Stahl Thomas Scheper Georg Garnweitner 《International journal of molecular sciences》2021,22(9)
The development of multifunctional nanoscale systems that can mediate efficient tumor targeting, together with high cellular internalization, is crucial for the diagnosis of glioma. The combination of imaging agents into one platform provides dual imaging and allows further surface modification with targeting ligands for specific glioma detection. Herein, transferrin (Tf)-decorated niosomes with integrated magnetic iron oxide nanoparticles (MIONs) and quantum dots (QDs) were formulated (PEGNIO/QDs/MIONs/Tf) for efficient imaging of glioma, supported by magnetic and active targeting. Transmission electron microscopy confirmed the complete co-encapsulation of MIONs and QDs in the niosomes. Flow cytometry analysis demonstrated enhanced cellular uptake of the niosomal formulation by glioma cells. In vitro imaging studies showed that PEGNIO/QDs/MIONs/Tf produces an obvious negative-contrast enhancement effect on glioma cells by magnetic resonance imaging (MRI) and also improved fluorescence intensity under fluorescence microscopy. This novel platform represents the first niosome-based system which combines magnetic nanoparticles and QDs, and has application potential in dual-targeted imaging of glioma. 相似文献
17.
This paper presents the results of experimental tests carried out to investigate the performance of a household refrigerator using a phase change material (PCM). The PCM is located on the back side of the evaporator in order to improve its efficiency and to provide a storage capacity allowing several hours of refrigeration without power supply. The system has been tested with water and with a eutectic mixture (freezing point ?3 °C) and for a range of operating conditions (PCM thickness, ambient temperature, thermal load). The analysis of the results shows a significant improvement of the performance compared to a conventional system. 相似文献
18.
Curtis B. Storlie Laura P. Swiler Jon C. Helton Cedric J. Sallaberry 《Reliability Engineering & System Safety》2009,94(11):1735-1763
The analysis of many physical and engineering problems involves running complex computational models (simulation models, computer codes). With problems of this type, it is important to understand the relationships between the input variables (whose values are often imprecisely known) and the output. The goal of sensitivity analysis (SA) is to study this relationship and identify the most significant factors or variables affecting the results of the model. In this presentation, an improvement on existing methods for SA of complex computer models is described for use when the model is too computationally expensive for a standard Monte-Carlo analysis. In these situations, a meta-model or surrogate model can be used to estimate the necessary sensitivity index for each input. A sensitivity index is a measure of the variance in the response that is due to the uncertainty in an input. Most existing approaches to this problem either do not work well with a large number of input variables and/or they ignore the error involved in estimating a sensitivity index. Here, a new approach to sensitivity index estimation using meta-models and bootstrap confidence intervals is described that provides solutions to these drawbacks. Further, an efficient yet effective approach to incorporate this methodology into an actual SA is presented. Several simulated and real examples illustrate the utility of this approach. This framework can be extended to uncertainty analysis as well. 相似文献
19.
Measurement of absorption and reduced-scattering optical coefficients a and s is possible when a steady-state backscattered image is used on a sample surface. A new method for processing the backscattered image, acquired with a CCD, has been developed. The image is integrated to decrease sensitivity to noise. The resulting curve is defined as the integral reflectance. The curve is then fitted with a relaxation model to evaluate a and s . We have validated the method with calibrated scattering and absorption phantoms. The integral reflectance method is then applied to measurements of the a and s coefficients of human skin in vivo . 相似文献
20.
The experimental results presented here have been obtained on a solar chicken brooder built in the Peruvian mountains (altitude 3000m, latitude 13°S). This installation is made of adobe and part of its roof is a solar collection-storage system consisting of two tanks of paraffin-wax located below glass panes. We study the short-range and long-range fluctuations of the variables characterizing the behaviour of the system and its fitness to its purpose: breeding young chickens that must be kept in a given range of temperature, with the air regularly renewed. 相似文献