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121.
Joanna Jaskowiak Jolanta Kwasniewska Miriam Szurman-Zubrzycka Magdalena Rojek-Jelonek Paul B. Larsen Iwona Szarejko 《International journal of molecular sciences》2020,21(22)
ATR, a DNA damage signaling kinase, is required for cell cycle checkpoint regulation and detecting DNA damage caused by genotoxic factors including Al3+ ions. We analyzed the function of the HvATR gene in response to chemical clastogen-maleic acid hydrazide (MH). For this purpose, the Al-tolerant barley TILLING mutant hvatr.g was used. We described the effects of MH on the nuclear genome of hvatr.g mutant and its WT parent cv. “Sebastian”, showing that the genotoxic effect measured by TUNEL test and frequency of cells with micronuclei was much stronger in hvatr.g than in WT. MH caused a significant decrease in the mitotic activity of root cells in both genotypes, however this effect was significantly stronger in “Sebastian”. The impact of MH on the roots cell cycle, analyzed using flow cytometry, showed no differences between the mutant and WT. 相似文献
122.
Miriam Saponaro Isabella Giacomini Giulia Morandin Veronica Cocetta Eugenio Ragazzi Genny Orso Ilaria Carnevali Massimiliano Berretta Mariangela Mancini Francesco Pagano Monica Montopoli 《International journal of molecular sciences》2020,21(23)
Benign prostatic hyperplasia (BPH) is an age-related chronic disorder, characterized by the hyperproliferation of prostatic epithelial and stromal cells, which drives prostate enlargement. Since BPH aetiology and progression have been associated with the persistence of an inflammatory stimulus, induced both by Nuclear Factor-kappa B (NF-κB) activation and reactive oxygen species (ROS) production, the inhibition of these pathways could result in a good tool for its clinical treatment. This study aimed to evaluate the antioxidant and anti-inflammatory activity of a combined formulation of Serenoa repens and Urtica dioica (SR/UD) in an in vitro human model of BPH. The results confirmed both the antioxidant and the anti-inflammatory effects of SR/UD. In fact, SR/UD simultaneously reduced ROS production, NF-κB translocation inside the nucleus, and, consequently, interleukin 6 (IL-6) and interleukin 8 (IL-8) production. Furthermore, the effect of SR/UD was also tested in a human androgen-independent prostate cell model, PC3. SR/UD did not show any significant antioxidant and anti-inflammatory effect, but was able to reduce NF-κB translocation. Taken together, these results suggested a promising role of SR/UD in BPH and BPH-linked disorder prevention. 相似文献
123.
124.
Peter Blaško Miriam Kupková Peter Futaš Andrea Vasilňaková 《Materials Science & Technology》2020,36(4):403-408
ABSTRACT The aim of the submitted work is to study the influence of applied loads (test forces) between 0.09807 and 2.9421?N on the measured value of micro-hardness of sintered Fe/3.3?wt-%Cu?+?CnHm. The Indentation Size Effect (ISE), i.e. the influence of the load on the micro-hardness is expected. The results were evaluated by Meyer’s index n, t-test, and non-parametric tests. The applied load has a statistically significant influence on the type and size of the ISE. Tested sintered material shows ‘normal’ ISE with Meyer’s index n?=?1.7588. 相似文献
125.
Alessandra Di Gaspare Eva Arianna Aurelia Pogna Luca Salemi Osman Balci Alisson Ronieri Cadore Sachin Maruti Shinde Lianhe Li Cinzia di Franco Alexander Giles Davies Edmund Harold Linfield Andrea Carlo Ferrari Gaetano Scamarcio Miriam Serena Vitiello 《Advanced functional materials》2021,31(10):2008039
An electrically switchable graphene terahertz (THz) modulator with a tunable-by-design optical bandwidth is presented and it is exploited to compensate the cavity dispersion of a quantum cascade laser (QCL). Electrostatic gating is achieved by a metal grating used as a gate electrode, with an HfO2/AlOx gate dielectric on top. This is patterned on a polyimide layer, which acts as a quarter wave resonance cavity, coupled with an Au reflector underneath. The authors achieve 90% modulation depth of the intensity, combined with a 20 kHz electrical bandwidth in the 1.9–2.7 THz range. The modulator is then integrated with a multimode THz QCL. By adjusting the modulator operational bandwidth, the authors demonstrate that the graphene modulator can partially compensate the QCL cavity dispersion, resulting in an integrated laser behaving as a stable frequency comb over 35% of the operational range, with 98 equidistant optical modes and a spectral coverage ~1.2 THz. This paves the way for applications in the terahertz, such as tunable transformation-optics devices, active photonic components, adaptive and quantum optics, and metrological tools for spectroscopy at THz frequencies. 相似文献
126.
Evaluation of catalytic properties of tungsten carbide for the anode of microbial fuel cells 总被引:5,自引:0,他引:5
Miriam Rosenbaum Feng Zhao Marion Quaas Harm Wulff Uwe Schrder Fritz Scholz 《Applied catalysis. B, Environmental》2007,74(3-4):261-269
In this communication we discuss the properties of tungsten carbide, WC, as anodic electrocatalyst for microbial fuel cell application. The electrocatalytic activity of tungsten carbide is evaluated in the light of its preparation procedure, its structural properties as well as the pH and the composition of the anolyte solution and the catalyst load. The activity of the noble-metal-free electrocatalyst towards the oxidation of several common microbial fermentation products (hydrogen, formate, lactate, ethanol) is studied for microbial fuel cell conditions (e.g., pH 5, room temperature and ambient pressure). Current densities of up to 8.8 mA cm−2 are achieved for hydrogen (hydrogen saturated electrolyte solution), and up to 2 mA cm−2 for formate and lactate, respectively. No activity was observed for ethanol electrooxidation.
The electrocatalytic activity and chemical stability of tungsten carbide is excellent in acidic to pH neutral potassium chloride electrolyte solutions, whereas higher phosphate concentrations at neutral pH support an oxidative degradation. 相似文献
127.
Mitochondrial cardiolipin synthase catalyzes the transfer of a phosphatidyl moiety from phosphatidyl-CMP PtdCMP) to phosphatidylglycerol
(PtdGro) in the presence of specific divalent cations. The synthase was solubilized fromSaccharomyces cerevisiae mitochondria and purified about 300-fold. The partially purified enzyme was part of a medium-size, mixed micelle which had
to bind to a foreign substrate/detergent micelle before catalysis could occur. The kinetics of cardiolipin synthase were studied
by changing the molar fraction of substrate in the micelles. The enzyme obeyed Michaelis-Menten kinetics in relation to PtdCMP
with aK
m of 0.03 mol%. PtdGro caused sigmoidal kinetics with a low apparent affinity. it is speculated that it was involved in docking
the enzyme to the substrate/detergent micelle. Cardiolipin synthase did not catalyze isotope exchange between [14C]CMP and PtdCMP, virtually excluding a ping-pong catalytic mechanism. Mg2+stimulated the activity by increasing the turnover number rather than the substrate affinity, a mechanism which was also found
for the Co2+-activation of rat liver cardiolipin synthase. It is concluded that a direct association of the metal ion and the enzyme forms
the active cardiolipin synthase which has a very high affinity for PtdCMP and a lower affinity for PtdGro. 相似文献
128.
Pranav Nawani Matt Lundwall Benjamin S. Hsiao Miriam Rafailovich Andy H. Tsou Syed Khalid 《Polymer》2007,48(3):827-840
A unique class of nanocomposites containing organoclays modified with catalytically active transition metal ions (TMI) and ethylene vinyl acetate (EVA) copolymers was prepared. The morphology, thermal and rheological properties of these nanocomposites were studied by thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), extended X-ray absorption fine structure (EXAFS) spectroscopy, X-ray scattering/diffraction and oscillatory shear rheometry. TMI-modified organoclays were thought to possess pillaring of multivalent TMI in the interlayer silicate gallery, leading to a notable reduction of the interlayer d-spacing. The resulting nanocomposites exhibited significantly improved thermal stability and fire retardation properties, but similar morphology (i.e., an intercalated-exfoliated structure) and rheological properties comparable with EVA nanocomposites containing unmodified organoclays. It appears that the compressed organic component in the TMI-modified organoclay can still facilitate the intercalation/exfoliation processes of polymer molecules, especially under extensive shearing conditions. The improved fire retardation in nanocomposites with TMI-modified organoclays can be attributed to enhanced carbonaceous char formation during combustion, i.e., charring promoted by the presence of catalytically active TMI. 相似文献
129.
Laboratory studies with live and frozen Maladera matrida female and male beetles showed that males were attracted to chemical substances emanating from the females at dusk. Beetles exhibited sexual activity (including mating) at dusk towards frozen females but not towards frozen males. Frozen females that had been extracted with methanol together with either hexane or dichloromethane or with a mixture of all three solvents did not elicit male sexual activity. Activity was fully restored when a concentrate of the extract was applied to the previously extracted frozen females. Males also responded with vigorous sexual activity to frozen males to which female extract had been applied. Deterrent chemicals appear to be absent from the male body. Males exposed to females that had been frozen during the morning displayed weak sexual activity, indicating that females lack active semiochemicals. Differences between dusk and morning extracts were found with respect to more than 20 compounds, some of which were present in much higher concentrations at dusk than in the morning, while others were not detected in the morning extract. The active component(s) of the short-range sex pheromone of female M. matrida is (are) presumably to be found among these compounds. 相似文献
130.
Diola Marina Núhez-Ramirez Aquiles Solis-Soto Javier López-Miranda Benito Perevra-Alférez Miriam Rutiaga-Quihónes Luis Medina-Torres Hiram Medrano-Roldán 《北京科技大学学报(英文版)》2011,18(5):523-526
The iron concentrate from Hercules Mine of Coahuila,Mexico,which mainly contained pyrite and pyrrhotite,was treated by the bioleaching process using native strain Acidithiobacillus ferrooxidans(A.ferrooxidans)to determime the ability of these bacteria on the leaching of zinc.The native bacteria were isolated from the iron concentrate of the mine.The bioleaching experiments were carried out in shake flasks to analyze the effects of pH values,pulp density,and the ferrous sulfate concentration on the bioleaching process.The results obtained by microbial kinetic analyses for the evaluation of some aspects of zinc leaching show that the native bacteria A.ferrooxidans,which is enriched with a 9K Silverman medium under the optimum conditions ofpH 2.0,20 g/L pulp density,and 40 g/L FeSO4,increases the zinc extraction considerably observed by monitoring duringl 5 d,i.e.,the zinc concentration has a decrease of about 95% in the iron concentrate. 相似文献