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651.
652.
Arturo Matamoros-Volante Valeria Castillo-Viveros Paulina Torres-Rodríguez Marcela B. Trevio Claudia L. Trevio 《International journal of molecular sciences》2021,22(1)
Plasma membrane (PM) hyperpolarization, increased intracellular pH (pHi), and changes in intracellular calcium concentration ([Ca2+]i) are physiological events that occur during human sperm capacitation. These parameters are potential predictors of successful outcomes for men undergoing artificial reproduction techniques (ARTs), but methods currently available for their determination pose various technical challenges and limitations. Here, we developed a novel strategy employing time-lapse flow cytometry (TLFC) to determine capacitation-related membrane potential (Em) and pHi changes, and progesterone-induced [Ca2+]i increases. Our results show that TLFC is a robust method to measure absolute Em and pHi values and to qualitatively evaluate [Ca2+]i changes. To support the usefulness of our methodology, we used sperm from two types of normozoospermic donors: known paternity (subjects with self-reported paternity) and no-known paternity (subjects without self-reported paternity and no known fertility problems). We found relevant differences between them. The incidences of membrane hyperpolarization, pHi alkalinization, and increased [Ca2+]i were consistently high among known paternity samples (100%, 100%, and 86%, respectively), while they varied widely among no-known paternity samples (44%, 17%, and 45%, respectively). Our results indicate that TLFC is a powerful tool to analyze key physiological parameters of human sperm, which pending clinical validation, could potentially be employed as fertility predictors. 相似文献
653.
Federica Campanelli Daniela Laricchiuta Giuseppina Natale Gioia Marino Valeria Calabrese Barbara Picconi Laura Petrosini Paolo Calabresi Veronica Ghiglieri 《International journal of molecular sciences》2021,22(4)
Food restriction is a robust nongenic, nonsurgical and nonpharmacologic intervention known to improve health and extend lifespan in various species. Food is considered the most essential and frequently consumed natural reward, and current observations have demonstrated homeostatic responses and neuroadaptations to sustained intermittent or chronic deprivation. Results obtained to date indicate that food deprivation affects glutamatergic synapses, favoring the insertion of GluA2-lacking α-Ammino-3-idrossi-5-Metil-4-idrossazol-Propionic Acid receptors (AMPARs) in postsynaptic membranes. Despite an increasing number of studies pointing towards specific changes in response to dietary restrictions in brain regions, such as the nucleus accumbens and hippocampus, none have investigated the long-term effects of such practice in the dorsal striatum. This basal ganglia nucleus is involved in habit formation and in eating behavior, especially that based on dopaminergic control of motivation for food in both humans and animals. Here, we explored whether we could retrieve long-term signs of changes in AMPARs subunit composition in dorsal striatal neurons of mice acutely deprived for 12 hours/day for two consecutive days by analyzing glutamatergic neurotransmission and the principal forms of dopamine and glutamate-dependent synaptic plasticity. Overall, our data show that a moderate food deprivation in experimental animals is a salient event mirrored by a series of neuroadaptations and suggest that dietary restriction may be determinant in shaping striatal synaptic plasticity in the physiological state. 相似文献
654.
Dr. Anna Maria Santoro Dr. Valeria Lanza Dr. Francesco Bellia Dr. Diego Sbardella Dr. Grazia R. Tundo Alessandra Cannizzo Prof. Giuseppe Grasso Dr. Mariaconcetta Arizzi Prof. Vincenzo G. Nicoletti Prof. Stefano Alcaro Dr. Giosuè Costa Dr. Adriana Pietropaolo Prof. Gaetano Malgieri Dr. Gianluca D'Abrosca Prof. Roberto Fattorusso Sara García-Viñuales Ikhlas M. M. Ahmed Prof. Massimiliano Coletta Dr. Danilo Milardi 《ChemMedChem》2020,15(3):302-316
Proteasome malfunction parallels abnormal amyloid accumulation in Alzheimer's Disease (AD). Here we scrutinize a small library of pyrazolones by assaying their ability to enhance proteasome activity and protect neuronal cells from amyloid toxicity. Tube tests evidenced that aminopyrine and nifenazone behave as 20S proteasome activators. Enzyme assays carried out on an “open gate” mutant (α3ΔN) proteasome demonstrated that aminopyrine activates proteasome through binding the α-ring surfaces and influencing gating dynamics. Docking studies coupled with STD-NMR experiments showed that H-bonds and π-π stacking interactions between pyrazolones and the enzyme play a key role in bridging α1 to α2 and, alternatively, α5 to α6 subunits of the outer α-ring. Aminopyrine and nifenazone exhibit neurotrophic properties and protect differentiated human neuroblastoma SH-SY5Y cells from β-amyloid (Aβ) toxicity. ESI-MS studies confirmed that aminopyrine enhances Aβ degradation by proteasome in a dose-dependent manner. Our results suggest that some pyrazolones and, in particular, aminopyrine are promising compounds for the development of proteasome activators for AD treatment. 相似文献
655.
Valeria Rodríguez-Fajardo Jonathan Pinnell Andrew Forbes 《Journal of Modern Optics》2020,67(13):1176-1183
Reducing the time necessary to acquire information is highly desirable in almost every context. Ghost imaging is no exception, which is very time consuming due to its scanning nature and low light levels innate to quantum experiments. This work aimed to reduce the time required to reconstruct the image whilst maintaining quality. In doing so, we followed two complementary approaches: one varying the experimental parameters, and another implementing computational processing. We defined a performance measure based on the image reconstruction time and its resemblance to the original object, and determined that the use of image processing and recognition algorithms offers major improvements in temporal efficiency. Importantly, if the main purpose of imaging is solely object recognition, low resolution mask patterns give better results, whereas higher resolution patterns yield better resolved images, at the expense of time. We believe this work will pique interest in the ghost and single-pixel imaging communities. 相似文献
656.
Nicolás Reyes Francisco Casado Valeria Tapia Claudio Jarufe Ricardo Finger Leonardo Bronfman 《Journal of Infrared, Millimeter and Terahertz Waves》2018,39(11):1140-1147
We report experimental values of the complex dielectric permittivity of a wide variety of engineering polymers. Measurements were done using the filling waveguide method at Q-band (30–50 GHz), being representative of the values over the millimeter wave regime. This method has a high accuracy, providing excellent wide-bandwidth characterization. Measured samples include the most common engineering materials as polyamide, polyethylene, polytetrafluoroethylene, polyoxymethylene, polylactic acid, phenol formaldehyde resin, polypropylene, polyvinyl chloride, acrylonitrile butadiene styrene, polyphenyle sulfide, and polyether ether ketone. Results are comprehensive and represent an important contribution to the technical literature which lacks of material measurements at these frequencies. Of particular interest are samples of 3D printed materials and high performance polymers, that will probably find new and novel applications in the field of microwave components and antennas for the millimeter wave band. 相似文献
657.
658.
Florent Tonus Valeria Fuster Guillermina Urretavizcaya Facundo J. Castro Jean-Louis Bobet 《International Journal of Hydrogen Energy》2009
The H sorption properties of mixtures Mg + WO3 (having various structures) and Mg + H0.23WO3 are reported. First, the higher conversion of Mg into MgH2 during reactive mechanical grinding (under 1.1 MPa of H2) for higher WO3 content is due to the improvement of the milling efficiency. Then, it is shown that the hydrogen absorption properties are almost independent of the crystal structure of the catalyst and that only the particles' size and the specific surface play a major role. Finally, for the desorption process, it appears that the chemical composition and structure of the catalyst, together with the particle size and specific surface have an effect. 相似文献
659.
660.
Elisabetta Princi Silvia Vicini Enrico Pedemonte Valeria Arrighi Iain J. McEwen 《应用聚合物科学杂志》2007,103(1):90-99
In the preservation of Cultural Heritage items, the use of polymeric materials for the consolidation and protection of artifacts with historical and artistic value is widely accepted, except for cellulose‐based materials, since here there are no suitable products and appropriate application techniques. Grafting polymerization of acrylic monomers onto cellulose chains represents an innovative method of restoration for both artificially and naturally aged textiles. In this article, some results concerning the grafting polymerization of ethyl acrylate/ethyl methacrylate 75/25 and ethyl acrylate/methyl methacrylate/trifluoroethyl methacrylate 73/24.5/2.5 polymers onto linen and cotton are reported. The effectiveness of grafting polymerization as a method for textiles conservation is discussed. The consolidating and protective effects were investigated by evaluating the mechanical properties and the wetting behavior of the grafted samples, and comparing them with the original and aged substrates. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 90–99, 2007 相似文献