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21.
Deniz Caylioglu Rieke Johanna Meyer Dana Hellmold Carolin Kubelt Michael Synowitz Janka Held-Feindt 《International journal of molecular sciences》2021,22(7)
Glioblastoma (GBM) is a barely treatable disease due to its profound chemoresistance. A distinct inter- and intratumoral heterogeneity reflected by specialized microenvironmental niches and different tumor cell subpopulations allows GBMs to evade therapy regimens. Thus, there is an urgent need to develop alternative treatment strategies. A promising candidate for the treatment of GBMs is AT101, the R(-) enantiomer of gossypol. The present study evaluates the effects of AT101, alone or in combination with temozolomide (TMZ), in a microenvironmental glioma stem cell niche model of two GBM cell lines (U251MG and U87MG). AT101 was found to induce strong cytotoxic effects on U251MG and U87MG stem-like cells in comparison to the respective native cells. Moreover, a higher sensitivity against treatment with AT101 was observed upon incubation of native cells with a stem-like cell-conditioned medium. This higher sensitivity was reflected by a specific inhibitory influence on the p-p42/44 signaling pathway. Further, the expression of CXCR7 and the interleukin-6 receptor was significantly regulated upon these stimulatory conditions. Since tumor stem-like cells are known to mediate the development of tumor recurrences and were observed to strongly respond to the AT101 treatment, this might represent a promising approach to prevent the development of GBM recurrences. 相似文献
22.
Journal of Applied Electrochemistry - In this study, within the defined orthogonal array of Taguchi design, the hydrothermal process parameters have been optimized for fabricating the smallest... 相似文献
23.
Effects of nitrite levels,endpoint temperature and storage on pink color development in turkey rolls
Eylem?Ezgi?Deniz Meltem?Serdaro?luEmail author 《European Food Research and Technology》2003,217(6):471-474
The objective of this research was to determine the relationship between minimum nitrite level, endpoint temperature and storage period on pink discoloration of turkey rolls. Rolls were prepared with 0, 3 or 5 parts per million (ppm) NO2–, cooked to an endpoint temperature of 75 °C or 85 °C and stored at 4 °C. During the 13-day storage period, on the 0th, 4th, 8th and 13th days cured pigment, total pigment, residual nitrite and color parameters were measured and sensory color was evaluated. At each endpoint temperature, addition of 3 ppm or 5 ppm NO2– significantly increased cured pigment and total pigment levels. Cured pigment levels of turkey rolls cooked to 75 °C were higher than rolls cooked to 85 °C, regardless of the NO2– level. There was a significant decrease in cured pigment levels at the end of the storage period (13th day). Analysis of residual NO2– in all treatment groups showed no detectable amounts. Endpoint temperature and addition of NO2– affected L* values: rolls cooked to the 75 °C endpoint had higher L* values. The additon of nitrite with the 75 °C endpoint temperature resulted in higher a* values. a* values also increased during the storage. The higher endpoint temperature (85 °C) resulted in lower a* values. Yellowness was not affected by final cooking temperature. Both the addition of NO2– and storage decreased b* values. The panel found no differences in pinkness intensity between the two levels of added nitrite (3 and 5 ppm). Sensory pinkness intensity in nitrite-added samples increased with increasing storage. 相似文献
24.
Mehdi Pourabdoli Shahram Raygan Hossein Abdizadeh Deniz Uner 《International Journal of Hydrogen Energy》2013
9Ni–2Mg–Y alloy powders were prepared by arc melting, induction melting, mechanical alloying, solid state reaction and subsequent ball milling processes. The results showed that melting processes are not suitable for preparation of 9Ni–2Mg–Y alloy due to high losses of Mg and Y. Therefore, 9Ni–2Mg–Y alloy powder was prepared by three methods including: 1) mechanical alloying, 2) mechanical alloying + solid state reaction + ball milling, and 3) mixing + solid state reaction + ball milling. The prepared 9Ni–2Mg–Y alloy powders were compared for their catalytic effects on hydrogen desorption of MgH2. It is found that 9Ni–2Mg–Y alloy powder prepared by mechanical alloying + solid state reaction + ball milling method has a smaller particle size (1–5 μm) and higher surface area (1.7 m2 g−1) than that of other methods. H2 desorption tests revealed that addition of 9Ni–2Mg–Y alloy prepared by mechanical alloying + solid state reaction + ball milling to MgH2 decreases the hydrogen desorption temperature of MgH2 from 425 to 210 °C and improves the hydrogen desorption capacity from 0 to 3.5 wt.% at 350 °C during 8 min. 相似文献
25.
Ergin Murat Altuner Hami Alpas Yasar Kemal Erdem Faruk Bozoglu 《European Food Research and Technology》2006,222(3-4):392-396
Interest in high hydrostatic pressure (HHP) applications on milk and dairy products has recently increased as HHP offers a
new technology for food preservation to the food industry. Although HHP-induced microbial destruction, rennet or acid coagulation
of milk and increase in cheese yield has been reported, the actual effect of HHP application on milk constituents still remains
to be unexplained. Therefore, we have analyzed the effect of HHP on physicochemical and biochemical properties such as turbidity,
pH and especially protein micelle surface hydrophobicity of milk proteins. To serve for this purpose, milk samples with different
fat contents were pressurized from 110 to 440 MPa at 25 °C for 10 and 20 min. Turbidity decreased with pressure increase and
there was a slight change in pH. In order to measure the extent of exposure of hydrophobic groups of proteins to HHP, the
method described by Bonomi et al. [1], based on use of a fluorescent probe, was utilized. In the light of the results obtained, it can be concluded that HHP has
an effect on non-covalent interactions and especially hydrophobic bonds in milk. As the pressure is increased from 110 to
440 MPa, the micelles possibly decompose into sub-micelles and the embedded hydrophobic areas inside these micelles re-position
in such a way that they can readily interfere with the fluorescent marker, ANS. These results may lead to practical applications
of HHP treatment in the dairy industry to produce microbiologically safe, minimally processed products with high nutritional
and sensory quality and novel texture. 相似文献
26.
Massimiliano Tomasulo Erhan Deniz Tiziana Benelli Salvatore Sortino Françisco M. Raymo 《Advanced functional materials》2009,19(24):3956-3961
Two macromolecular constructs incorporating a single polymer backbone with multiple photochromic side chains are developed. Both systems are prepared from preformed photochromic [1,3]oxazines after the ring‐opening polymerization of their norbornene appendages. In solution, UV illumination of these polymers opens the [1,3]oxazine rings in their side chains in less than 6 ns and with a quantum yield of 0.09 in both instances. The photogenerated species incorporate a 4‐nitrophenolate chromophore, and hence, their formation is accompanied by the appearance of an intense band in the visible region of the absorption spectrum. The photoproducts revert spontaneously to the original state with first‐order kinetics in microseconds. Furthermore, both photochromic polymers tolerate hundreds of switching cycles with no sign of degradation, even in the presence of molecular oxygen. Thus, this design logic and choice of functional building blocks can translate into the realization of innovative photoresponsive materials with excellent photochromic performance. 相似文献
27.
The special interaction between 3-aminophenylboronic acid and monosaccharides, particularly glucose, fructose and galactose, has been investigated and used for the development of electrochemical and surface plasmon resonance (SPR) based saccharide sensors. The binding constants and thermodynamic parameters of interaction such as free energy of binding (ΔG), enthalpy (ΔH) and entropy (ΔS) were determined for the first time using isothermal titration calorimetry revealed the enthalpic and entropic contributions to the free energies of binding. Effects of pH and buffer on the binding constants (k) between 3-aminophenylboronic acid and monosaccharides were also examined. The binding constant of fructose was found to be six times higher than glucose and four times higher than galactose at pH 11, leading the specific detection of fructose. SPR and potentiometric calibration for fructose were linear in the concentration range of 10–120 mM and 8–84 mM, respectively. Limit of detection of the SPR and potentiometric method were found to be as 8.9 mM and 1.4 mM, respectively. 相似文献
28.
Deniz Akta Uygun A. Alev Karagzler Sinan Akgl Adil Denizli 《Materials science & engineering. C, Materials for biological applications》2009,29(7):2165-2173
N-Methacryloyl-l-phenylalanine (MAPA) containing poly(2-hydroxyethylmethacrylate) based magnetic [mag-poly(HEMA–MAPA)] nanobeads was prepared for lysozyme purification form chicken egg white. MAPA was synthesized by reacting methacryloyl chloride with l-phenylalanine methyl ester and provided hydrophobic functionality to the nanobeads. Size of mag-poly(HEMA–MAPA) nanobeads was 386 nm and obtained by surfactant free emulsion polymerization of HEMA and MAPA having a specific surface area of 580 m2/g. Mag-poly(HEMA–MAPA) nanobeads were characterized by FTIR, AFM, TEM, ESR, and elemental analysis. Lysozyme adsorption experiments were investigated under different conditions in batch system (i.e., medium pH, protein concentration, temperature, salt type). Lysozyme adsorption capacity of mag-poly(HEMA) and mag-poly(HEMA–MAPA) nanobeads from aqueous solutions was estimated as 24 and 517 mg/g, respectively. Lysozyme molecules were desorbed with 50% ethylene glycol solution with 98% recovery. It was observed that mag-poly(HEMA–MAPA) nanobeads can be used without significant decrease in lysozyme adsorption capacity after ten adsorption–desorption cycles. Mag-poly(HEMA–MAPA) nanobeads was used for the purification of lysozyme from chicken egg white. Purity of lysozyme was estimated by SDS-PAGE. 相似文献
29.
Minimum output mutual information is regarded as a natural criterion for independent component analysis (ICA) and is used as the performance measure in many ICA algorithms. Two common approaches in information-theoretic ICA algorithms are minimum mutual information and maximum output entropy approaches. In the former approach, we substitute some form of probability density function (pdf) estimate into the mutual information expression, and in the latter we incorporate the source pdf assumption in the algorithm through the use of nonlinearities matched to the corresponding cumulative density functions (cdf). Alternative solutions to ICA use higher-order cumulant-based optimization criteria, which are related to either one of these approaches through truncated series approximations for densities. In this article, we propose a new ICA algorithm motivated by the maximum entropy principle (for estimating signal distributions). The optimality criterion is the minimum output mutual information, where the estimated pdfs are from the exponential family and are approximate solutions to a constrained entropy maximization problem. This approach yields an upper bound for the actual mutual information of the output signals - hence, the name minimax mutual information ICA algorithm. In addition, we demonstrate that for a specific selection of the constraint functions in the maximum entropy density estimation procedure, the algorithm relates strongly to ICA methods using higher-order cumulants. 相似文献
30.
Dilchert Stephan; Ones Deniz S.; Davis Robert D.; Rostow Cary D. 《Canadian Metallurgical Quarterly》2007,92(3):616
Over the past 2 decades, increasing attention has been directed at the relationship between individual differences and counterproductive work behaviors (CWB). However, most of this research has focused on personality variables as potential predictors of CWB; surprisingly little research has investigated the link between counterproductivity and cognitive ability. This study presents the first focal investigation of the cognitive ability-CWB relationship. The authors measured organizational and interpersonal CWB using organizational records of formally recorded incidents (e.g., destruction of property, physical violence). In a predictive study, for a large sample of law enforcement job applicants, a standardized psychometric test of cognitive ability predicted CWB, whereas educational attainment did not. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献