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排序方式： 共有580条查询结果，搜索用时 15 毫秒
551.
552.
Evan D. Miller Matthew L. Jones Mike M. Henry Bryan Stanfill Eric Jankowski 《American Institute of Chemical Engineers》2019,65(12):e16760
The purpose of this work is to lower the computational cost of predicting charge mobilities in organic semiconductors, which will benefit the screening of candidates for inexpensive solar power generation. We characterize efforts to minimize the number of expensive quantum chemical calculations we perform by training machines to predict electronic couplings between monomers of poly-(3-hexylthiophene). We test five machine learning techniques and identify random forests as the most accurate, information-dense, and easy-to-implement approach for this problem, achieving mean-absolute-error of 0.02 [× 1.6 × 10−19 J], R2 = 0.986, predicting electronic couplings 390 times faster than quantum chemical calculations, and informing zero-field hole mobilities within 5% of prior work. We discuss strategies for identifying small effective training sets. In sum, we demonstrate an example problem where machine learning techniques provide an effective reduction in computational costs while helping to understand underlying structure–property relationships in a materials system with broad applicability. 相似文献
553.
Sijia Yi Xiaohan Zhang M. Hussain Sangji Yugang Liu Sean D. Allen Baixue Xiao Sharan Bobbala Cameron L. Braverman Lei Cai Peter I. Hecker Matthew DeBerge Edward B. Thorp Ryan E. Temel Samuel I. Stupp Evan A. Scott 《Advanced functional materials》2019,29(42)
The principle cause of cardiovascular disease (CVD) is atherosclerosis, a chronic inflammatory condition characterized by immunologically complex fatty lesions within the intima of arterial vessel walls. Dendritic cells (DCs) are key regulators of atherosclerotic inflammation, with mature DCs generating pro‐inflammatory signals within vascular lesions and tolerogenic DCs eliciting atheroprotective cytokine profiles and regulatory T‐cell (Treg) activation. Here, the surface chemistry and morphology of synthetic nanocarriers composed of poly(ethylene glycol)‐b‐poly(propylene sulfide) copolymers to enhance the targeted modulation of DCs by transporting the anti‐inflammatory agent 1,25‐dihydroxyvitamin D3‐(aVD) and ApoB‐100‐derived antigenic peptide P210 are engineered. Polymersomes decorated with an optimized surface display and density for a lipid construct of the P‐D2 peptide, which binds CD11c on the DC surface, significantly enhance the cytosolic delivery and resulting immunomodulatory capacity of aVD in vitro. Weekly low‐dose intravenous administration of DC‐targeted, aVD‐loaded polymersomes significantly inhibit atherosclerotic lesion development in high‐fat‐diet‐fed ApoE?/? mice. The results validate the key role of DC immunomodulation during aVD‐dependent inhibition of atherosclerosis and demonstrate the therapeutic enhancement and dosage lowering capability of cell‐targeted nanotherapy in the treatment of CVD. 相似文献
554.
Christabel C. Ngetich James Mutua Patrick Kareru Kabini Karanja Evan Wanjiru 《Fuel Cells》2023,23(5):324-337
Proton exchange membrane (PEM) fuel cell has emerged as a promising alternative to fossil fuels as it is employed to generate electricity for portable applications with low carbon emissions. However, the high cost of the technology hinders its widespread commercialization. Optimizing PEM fuel cell model parameters is crucial in performance improvement and production cost reduction. This study presents an optimization approach for a PEM fuel cell operating and design parameters by integrating Taguchi and Response Surface Methodology. A 3D-CFD model of a PEM fuel cell is developed and used as a base model for the optimization study. Thirteen input parameters with notable effects on the fuel cell's performance are selected for this study. By the Taguchi method, these parameters decreased from thirteen to five. A response surface methodology (RSM) Box-Behnken experimental design is employed to study the interactions of the parameters on the power density. The optimum working parameters that result in optimum power density of 0.8476 W cm−2 include an operating pressure (2.5 bar), temperature (80°C), flow channel width (1.30 mm), membrane thickness (0.036 mm), and catalyst layer thickness of 0.01 mm. This study provides a quick and efficient way of optimizing PEM fuel cell model for maximum power density. 相似文献
555.
Chao Wang Zhenfeng He Xiaofeng Xie Xianmin Mai Yingchun Li Tingxi Li Min Zhao Chao Yan Hu Liu Evan K. Wujcik Zhanhu Guo 《大分子材料与工程》2018,303(3)
A new monomer called 2,2′‐(4,4′‐oxydiphenol‐4,4′‐diyl)bis(2‐methyl‐2,3,3a,4,7,7a‐hexahydro‐1H‐4,7‐methanoisoindol‐2‐ium) iodide (d3) is synthesized possessing both cross‐linker and functional groups. The membranes are formed by copolymerizing d3 with norbornene and (3aR,4S,7R,7aS)‐2‐methyl‐2‐(3‐(trimethylammonio)propyl)‐2,3,3a,4,7,7a‐hexahydro‐1H‐4,7‐methanoisoindol‐2‐ium iodide (a3) at varying ratios. The water uptake is 41.35% at 60 °C, and ion exchange capacity is 2.35 mequiv g?1 for a mole ratio of a3, norbornene, and d3 (1:6:3). The conductivity is 12, 37, and 40 mS cm?1 when d3 is decreased. Meanwhile, the conductivity increases quickly with increasing the temperature. Furthermore, the mechanical properties and thermal properties are improved, attributed to the increased cross‐linker. The membrane has a tensile strength of 41.3 MPa and the elongation at break of 38.0 %, and the 5 wt% loss temperature for membrane is ≈159 °C. The H2/O2 single fuel cells with this membrane show a maximum power density of 124 mW cm?2 at 50 °C. The cross‐linked membranes demonstrate high‐dimensional stability in alkaline solution. 相似文献
556.
Brittany Rupp Sarah Owen Harrison Ball Kaylee Judith Smith Valerie Gunchick Evan T. Keller Vaibhav Sahai Sunitha Nagrath 《International journal of molecular sciences》2022,23(14)
As pancreatic cancer is the third deadliest cancer in the U.S., the ability to study genetic alterations is necessary to provide further insight into potentially targetable regions for cancer treatment. Circulating tumor cells (CTCs) represent an especially aggressive subset of cancer cells, capable of causing metastasis and progressing the disease. Here, we present the Labyrinth–DEPArray pipeline for the isolation and analysis of single CTCs. Established cell lines, patient-derived CTC cell lines and freshly isolated CTCs were recovered and sequenced to reveal single-cell copy number variations (CNVs). The resulting CNV profiles of established cell lines showed concordance with previously reported data and highlight several gains and losses of cancer-related genes such as FGFR3 and GNAS. The novel sequencing of patient-derived CTC cell lines showed gains in chromosome 8q, 10q and 17q across both CTC cell lines. The pipeline was used to process and isolate single cells from a metastatic pancreatic cancer patient revealing a gain of chromosome 1q and a loss of chromosome 5q. Overall, the Labyrinth-DEPArray pipeline offers a validated workflow combining the benefits of antigen-free CTC isolation with single cell genomic analysis. 相似文献
557.
Md Didarul Islam Jun Oh Kim Yeongun Ko Zahyun Ku Darryl A. Boyd Evan M. Smith Vinh Q. Nguyen Jason D. Myers Colin C. Baker Woohong Kim Jasbinder S. Sanghera David A. Czaplewski Augustine M. Urbas Jan Genzer Jong E. Ryu 《大分子材料与工程》2020,305(5)
While an organically modified chalcogenide (ORMOCHALC) can be used to fabricate a polymeric mid‐wavelength infrared (MWIR) polarizer with competitive extinction ratio compared to the commercial wire‐grid polarizers, which are composed of fragile inorganic materials, there is still a knowledge gap regarding the systematic design process to obtain high transmission efficiency and extinction ratio. To this end, a computational parameter study for design optimization is conducted with the geometric parameters of the bilayer grating ORMOCHALC polarizer. The computational study shows that the Fabry–Pérot cavity is the primary mechanism that determines the transmission behaviors and the extinction ratio. A bilayer grating design, guided by the parameter study, is realized through the thermal nanoimprint and metal deposition processes. The extinction ratios measured with the Fourier‐transform infrared are 245, 304, and 351 at the wavelength of 3, 4, and 5 µm, respectively. Compared to the state‐of‐the‐art of the polymeric MWIR linear polarizers, the extinction ratio is improved by 1.4 times, and the transmission efficiency is increased by 2.5 times. Theoretical analysis with the multiple‐layer model based on the transfer matrix method predicts a matched transmission behavior with the experiment and a full‐wave electromagnetic simulation. 相似文献
558.
This investigation presents a holistic and comprehensive assessment of the stepwise changes in barley quality during the malting process for multiple batches of two Australian malting varieties (Buloke and Gairdner), in two modern, commercial scale pneumatic malthouses. The study sought to analyse and compare malting plant and variety with respect to basic changes in malt quality for protein (total protein and free amino nitrogen), fermentability (apparent attenuation limit and diastatic power), extract yield, along with filtration indicators (lautering efficiency, viscosity and β-glucan). Overall, comparing the two malt plants, it was observed that although malt batches and varieties followed different malting pathways, the finished and kilned malt was of satisfactory quality in terms of FAN, viscosity, friability, fermentability and extract. © 2020 The Institute of Brewing & Distilling 相似文献
559.
Adsorption of polluting substances on activated carbons prepared from rice husk and sugarcane bagasse 总被引：2，自引：0，他引：2
Dimitrios Kalderis Dimitrios Koutoulakis Panagiota Paraskeva Evan Diamadopoulos Emilia Otal Joaquín Olivares del Valle Constantino Fernndez-Pereira 《Chemical engineering journal (Lausanne, Switzerland : 1996)》2008,144(1):42-50
Rice husk and sugarcane bagasse were chemically impregnated with ZnCl2 and carbonized at 700 °C in a large-scale rotary furnace. The activated carbons (ACs) obtained had BET surface area of 811 and 864 m2/g, respectively, and were essentially microporous. The adsorption of arsenic, humic acid, phenol and a municipal solid waste landfill leachate was examined. Both ACs showed the best adsorption behaviour towards phenol, removing around 80% at the equilibrium time of 4 h. The adsorption isotherms for arsenic and humic acid were also favourable, although the maximum loadings achieved were lower than that of phenol. Finally, the rice husk AC showed 60% and 70% removal efficiency for colour and COD, respectively, when tested on a landfill leachate. 相似文献
560.
Regiospecific and traditional analysis, of both storage and membrane lipids, was performed on gill, white muscle, and red
muscle samples taken from Atlantic salmon (Salmo salar) to gauge the effect of elevated water temperature. The fish, fed a commercial diet, were held at an elevated water temperature
of 19°C. Total n-3 PUFA, total PUFA, and n-3/n-6 and unsaturated/saturated fatty acid (UFA/SFA) ratios in the FA profile of
the total lipid extract in the white muscle were fairly low compared with fish grown at 15°C. Adaptation of structural and
storage lipids at elevated temperatures was shown by a significant (P<0.01) reduction in PUFA especially in the percentage of EPA (6–8%). Further adaptation was indicated by the percentages of
SFA, which were significantly (P<0.05) higher in gill (56%) and white muscle (58%) polar lipid fractions and coincided with lower percentages of n-3, n-6,
and total PUFA. The regiospecific profiles indicated a high affinity of DHA to the sn-2 position in both the TAG (61–68%) and polar lipid (35–60%) fractions. The combination of detailed regiospecific and lipid
analyses demonstrated adaptation of cell membrane structure in Atlantic salmon grown at an elevated water temperature. 相似文献