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141.
The 2-amino-5-(3/4-fluorostyryl)acetophenones were prepared and reacted with benzaldehyde derivatives to afford the corresponding 5-styryl-2-aminochalcone hybrids. The trans geometry of the styryl and α,β-unsaturated carbonyl arms, and the presence of NHO intramolecular hydrogen bond were validated using 1H-NMR and X-ray data. The 2-amino-5-styrylacetophenones and their 5-styryl-2-aminochalcone derivatives were screened in vitro for their capability to inhibit α-glucosidase and/or α-amylase activities. Their antioxidant properties were evaluated in vitro through the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO) free radical scavenging assays. Kinetic studies of the most active derivatives from each series against α-glucosidase and/or α-amylase activities have been performed supported by molecular docking studies to determine plausible protein–ligand interactions on a molecular level. The key aspects of the pharmacokinetics of these compounds, i.e., absorption, distribution, metabolism, and excretion have also been simulated at theoretical level. The most active compounds from each series, namely, 2a and 3e, were evaluated for cytotoxicity against the normal monkey kidney cells (Vero cells) and the adenocarcinomic human epithelial (A549) cell line to establish their safety profile at least in vitro.  相似文献   
142.
Solar-driven photocatalysis holds great potential for energy conversion, environmental remediation, and sustainable chemistry. However, practical applications of conventional photocatalytic systems have been constrained by their insufficient ability to harvest solar radiation in the infrared spectrum. Lanthanide-doped upconversion materials possess high photostability, tunable absorption, and the ability to convert low-energy infrared radiation into high-energy emission, making them attractive for infrared-driven photocatalysis. This review highlights essential principles for rational design of efficient photocatalysts. Particular emphasis is placed on current state-of-the-arts that offer enhanced upconversion luminescence efficiency. We also summarize recent advances in lanthanide-doped upconversion materials for photocatalysis. We conclude with new challenges and prospects for future developments of infrared-driven photocatalysts.  相似文献   
143.
Previously synthesized amphiphilic diblock copolymers with pendant dendron moieties have been investigated for their potential use as drug carriers to improve the delivery of an anticancer drug to human breast cancer cells. Diblock copolymer (P71D3)‐based micelles effectively encapsulate the doxorubicin (DOX) with a high drug‐loading capacity (≈95%, 104 DOX molecules per micelle), which is approximately double the amount of drug loaded into the diblock copolymer (P296D1) vesicles. DOX released from the resultant P71D3/DOX micelles is approximately 1.3‐fold more abundant, at a tumoral acidic pH of 5.5 compared with a pH of 7.4. The P71D3/DOX micelles also enhance drug potency in breast cancer MDA‐MB‐231 cells due to their higher intracellular uptake, by approximately twofold, compared with the vesicular nanocarrier, and free DOX. Micellar nanocarriers are taken up by lysosomes via energy‐dependent processes, followed by the release of DOX into the cytoplasm and subsequent translocation into the nucleus, where it exert its cytotoxic effect.

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144.
The construction sector plays an important role in a country’s economic development. The financial performance of a company is a good indicator of its financial health and status. In Malaysia, the government encourages the construction industry to develop an advanced infrastructure related to health, transport, education and housing. In view of the COVID-19 pandemic, the operations and financial performance of construction sector companies have been affected recently. Additionally, uncertainty plays a vital role in the multi-criteria decision-making (MCDM) process. Based on previous studies, there has been no comprehensive study conducted on the evaluation of the financial performance of construction companies by integrating entropy and fuzzy VIKOR models. Therefore, this paper aims to propose an MCDM model to evaluate and compare the financial performance of construction companies with an integrated entropy–fuzzy VIKOR model. A case study is carried out by evaluating the listed construction companies in Malaysia with the proposed model. The findings of this paper indicate that the company ECONBHD achieves the best financial performance over the study period. The significance of this paper is to determine the priority of the financial ratios and ranking of the construction companies with the proposed entropy–fuzzy VIKOR model.  相似文献   
145.
Multi‐walled carbon nanotube (MWCNT)/polypropylene (PP) composites were prepared by a micro melt mixing process. As‐prepared composites had relatively low electrical conductivity due to the disruption of MWCNT network by strong shear. The electrical conductivity jumped to high values throughout an annealing process above the melting temperature of PP. The significant enhancement of electrical conductivity was influenced by annealing time, temperature, and content of MWCNTs. In particular, molecular weight of PP played an important role in affecting the conductivity enhancement. The molecular weight of PP was varied from 190,000 to 340,000 to examine its effect on the electrical conductivity. By comparing the conductivity enhancement behavior of composites with different molecular weight PPs and observing the morphology evolution during annealing, it was found that reaggregation of MWCNTs and the subsequent formation of MWCNT network during annealing are the main reasons for the jump of electrical conductivity. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010  相似文献   
146.
We report a new approach for generating an Airy beam by using a digital micromirror device (DMD) and a holographic technique where the DMD loads the desired hologram. Unique characteristics of an Airy beam, such as the non-diffraction and self-acceleration properties, were demonstrated to prove the successful construction of this type of waveform. Experimental results showed good agreement with theoretical calculations. This approach can also be used to generate other special beams.  相似文献   
147.
148.
Since the last decade, minimal spanning trees (MSTs) have become one of the main streams in econophysics to filter the important information contained, for example, in stock networks. The standard practice to find an MST is by using Kruskal’s algorithm. However, it becomes slower and slower when the number of stocks gets larger and larger. In this paper we propose an algorithm to find an MST which has considerably promising performance. It is significantly faster than Kruskal’s algorithm and far faster if there is only one unique MST in the network. Our approach is based on the combination of fuzzy relation theory and graph theoretical properties of the forest of all MSTs. A comparison study based on real data from four stock markets and four types of simulated data will be presented to illustrate the significant advantages of the proposed algorithm.  相似文献   
149.
This article introduces a newly innovative idea for preparation of superconductive ternary polymeric composites of polyamide 6 (PA6), conductive carbon black (CCB), and multiwalled carbon nanotubes (MWCNTs) with different weight ratios by a melt‐mixing technique. The complementary effects of CCB and MWCNTs at different compositions on rheological, physical, morphological, thermal, and dynamic mechanical and electrical properties of the ternary composites have been examined systematically. We have used a novel formulation to produce high‐weight fraction ternary polymer composites that show extremely higher conductivity when compared with their corresponding binary polymer composites at the same carbon loading. For example, with an addition of 10 wt % MWCNTs into the CCB/PA6 composite preloaded with 10 wt % CCB, the electrical conductivity of these ternary composites was about 5 S/m, which was 10 times that of the CCB/PA6 binary composite (0.5 S/m) and 125 times that of the MWCNT/PA6 binary composite (0.04 S/m) at 20 wt % carbon loading. The incorporation of the MWCNTs effectively enhanced the thermal stability and crystallization of the PA6 matrix in the CCB/PA6 composites through heterogeneous nucleation. The MWCNTs appeared to significantly affect the mechanical and rheological properties of the PA6 in the CCB/PA6 composites, a way notably dependent on the MWCNT contents. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1203–1212, 2010  相似文献   
150.
The title compound, ethyl 2-(4-methoxyphenyl)-1H-benzo[d]imidazole-5-carboxylate dihydrate (5), was synthesized and its crystal structure was studied by single-crystal X-ray diffraction technique. Compound 5 is crystallized in the centrosymmetric triclinic space group \(P\bar {1}\) with Z?=?4 and Z′?=?2, and unit-cell parameters of a?=?8.9190 (3) Å, b?=?12.6888 (4) Å, c?=?14.7111 (5) Å, α?=?98.4855 (10)°, β?=?101.6379 (9)°, γ?=?95.4346 (10)° and V?=?1599.43 (9) Å3. Its starting material, 4-fluoro-3-nitrobenzoic acid (1), is crystallized in the non-centrosymmetric monoclinic space group P21 and Z?=?4 with unit-cell parameters of a?=?3.7170 (4) Å, b?=?12.6475 (13) Å, c?=?15.5237 (15) Å, α?=?90°, β?=?91.9786 (16)°, γ?=?90° and V?=?729.35 (13) Å3. It was noted that strong hydrogen bonds play important roles in the crystal packing of both compounds, especially in 5, in which the co-crystallized water molecules act as both strong hydrogen bond donor and strong hydrogen bond acceptor.

Graphical Abstract

Two molecule of compound 5 crystallized in a non symmetrical manner with four co-crystallized water molecules which play an important role in the crystal packing as strong hydrogen-bond donors.
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