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51.
Immunogenic cell death (ICD) offers a method of stimulating the immune system to attack and remove cancer cells. We report a copper(II) complex containing a Schiff base ligand and a polypyridyl ligand, 4 , capable of inducing ICD in breast cancer stem cells (CSCs). Complex 4 kills both bulk breast cancer cells and breast CSCs at sub-micromolar concentrations. Notably, 4 exhibits greater potency (one order of magnitude) towards breast CSCs than salinomycin (an established breast CSC-potent agent) and cisplatin (a clinically approved anticancer drug). Epithelial spheroid studies show that 4 is able to selectively inhibit breast CSC-enriched HMLER-shEcad spheroid formation and viability over non-tumorigenic breast MCF10 A spheroids. Mechanistic studies show that 4 operates as a Type II ICD inducer. Specifically, 4 readily enters the endoplasmic reticulum (ER) of breast CSCs, elevates intracellular reactive oxygen species (ROS) levels, induces ER stress, evokes damage-associated molecular patterns (DAMPs), and promotes breast CSC phagocytosis by macrophages. As far as we are aware, 4 is the first metal complex to induce ICD in breast CSCs and promote their engulfment by immune cells.  相似文献   
52.
The use of phase‐transfer catalysts, with water‐insoluble initiators, for polymerization and graft copolymerization reactions was explored. The polymerization of a water‐soluble vinyl monomer, acrylamide (AAm), and the graft copolymerization of AAm onto a water‐insoluble polymer backbone, isotactic polypropylene (IPP), with a water‐insoluble initiator, benzoyl peroxide (BPO), and a phase‐transfer catalyst, tetrabutyl ammonium bromide (Bu4N+Br?), were carried out in a water/xylene binary solvent system. The conversion percentage of AAm into polyacrylamide (PAAm) and the percentage of grafting of AAm onto IPP were determined as functions of various reaction parameters, such as the BPO, AAm, and phase‐transfer‐catalyst concentrations, the amounts of water and xylene in the water/xylene mixture, the time, and the temperature. The graft copolymer, IPP‐g‐PAAm, was characterized with IR spectroscopy and thermogravimetric analysis. By a comparison of the results of the phase‐transfer‐catalyzed graft copolymerization of AAm onto IPP and the preirradiation method, it was observed that the optimum reaction conditions were milder for the phase‐transfer‐catalyst‐aided graft copolymerization. Milder reaction conditions, including the temperature, the time of reaction, and a moderate initiator (BPO), in comparison with high‐energy γ‐rays, led to better quality products, and the reaction proceeded smoothly with high productivity. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2364–2375, 2004  相似文献   
53.
Extrusion behavior of grits obtained from 3 successive reductions of dry milling of 2 normal corn types and 1 waxy corn was studied at different extrusion temperatures (ET). The grit from each reduction stage (RS) showed the presence of base‐hydrolyzed bound protocatechuic acid, p‐coumaric acid, sinapic acid, ferulic acid, and quercetin, and the concentrations of these decreased after acid hydrolysis and that of gallic acid increased. African tall grit from all RSs showed the highest average specific mechanical energy (SME) and torque, while waxy corn grit had the lowest. Corn extrudates showed an increase in water solubility index (WSI) and a decrease in water absorption index (WAI), as well as in expansion ratio (ER) with an increase in ET. Extrudates from each corn type showed an increase in rapidly digestible starch (RDS) and a decrease in slowly digestible starch (SDS) and resistant starch with an increase in ET. Most of the phenolics were present in bound form in extrudates, and quercetin, and catechin observed in grit were not present in extrudates. Frying of extrudates showed lower L* and higher a* and b* when compared to color parameters of raw extrudates. Lower expansion of fried extrudates from waxy corn than those from other corn types may be related to its higher protein and fat contents and to lower amylose content.  相似文献   
54.
The effect of high-pressure processing on quality and shelf life of black tiger shrimp was studied. Shrimp was high-pressure processed at selected pressure levels of 100, 270, and 435 MPa for 5 min at room temperature (25?±?2 °C). Changes in physical, biochemical, and microbiological characteristics after processing and during subsequent chilled storage were examined for 35 days. After processing significant (P?<?0.05) increase in moisture content and parallel reduction in protein content was observed. No significant changes were observed in TVB-N and TMA-N levels of shrimp after processing; however, these significantly increased with storage. Whiteness index increased with pressure intensity imparting brighter and mildly cooked appearance. Pressure-induced hardening effect was observed, which showed decreasing trend during storage. The treated samples maintained lower viable counts throughout the storage, thus having better microbial quality than untreated sample. Shelf life was extended to 15 days in shrimp treated at 435 MPa compared with 5 days in untreated sample. Pressure treatment of 435 MPa was found to be most effective in preserving the quality and extending the shelf life of black tiger shrimp.  相似文献   
55.
The NAD+‐dependent deacetylases, namely sirtuins, are involved in the regulation of a variety of biological processes such as gene silencing, DNA repair, longevity, metabolism, apoptosis, and development. An enzyme from the parasite Leishmania infantum that belongs to this family, LiSIR2RP1, is a NAD+‐dependent tubulin deacetylase and an ADP‐ribosyltransferase. This enzyme's involvement in L. infantum virulence and survival underscores its potential as a drug target. Our search for selective inhibitors of LiSIR2RP1 has led, for the first time, to the identification of the antiparasitic and anticancer bisnaphthalimidopropyl (BNIP) alkyl di‐ and triamines (IC50 values in the single‐digit micromolar range for the most potent compounds). Structure–activity studies were conducted with 12 BNIP derivatives that differ in the length of the central alkyl chain, which links the two naphthalimidopropyl moieties. The most active and selective compound is the BNIP diaminononane (BNIPDanon), with IC50 values of 5.7 and 97.4 μM against the parasite and human forms (SIRT1) of the enzyme, respectively. Furthermore, this compound is an NAD+‐competitive inhibitor that interacts differently with the parasite and human enzymes, as determined by docking analysis, which might explain its selectivity toward the parasitic enzyme.  相似文献   
56.
This article deals with the propagation of SH-wave in a vertically heterogeneous viscoelastic layer lying over a micropolar elastic half-space. Dispersion and damping equations are obtained analytically in closed form. Phase and damped velocities are computed numerically and depicted by means of a graph to exhibit the substantial effect of heterogeneity, viscoelasticity (internal friction), and micropolar parameter. As a special case of the problem, it is found that deduced dispersion relation is well in agreement to the classical-Love wave equation and damping equation vanishes identically for the isotropic case. Influence of micropolarity present in the medium of half-space is highlighted through comparative study.  相似文献   
57.
58.
In this paper we report doping induced enhanced sensor response of SnO2 based sensor towards ethanol at a working temperature of 200 °C. Undoped and dysprosium-doped (Dy-doped) SnO2 nanoparticles were characterized by X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). XRD and Raman results verified tetragonal rutile structure of the prepared samples. It has been observed that crystallite size reduced with increase in dopant concentration. In addition, the particle size has been calculated from Raman spectroscopy using phonon confinement model and the values match very well with results obtained from TEM and X-ray diffraction investigations. Dy-doped SnO2 sensors exhibited significantly enhanced response towards ethanol as compared to undoped sensor. The optimum operating temperature of doped sensor reduced to 200 °C as compared to 320 °C for that of undoped sensor. Moreover, sensor fabricated from Dy-doped SnO2 nanostructures was highly selective toward ethanol which signifies its potential use for commercial applications. The gas sensing mechanism of SnO2 and possible origin of enhanced sensor response has been discussed.  相似文献   
59.
Wireless Personal Communications - Recently, the theory of effective rate has attracted much attention, since it can take the delay aspect into account when performing channel capacity analysis. In...  相似文献   
60.
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