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排序方式: 共有489条查询结果,搜索用时 15 毫秒
1.
Romina Romaniello Ludovica Pasca Elena Panzeri Fulvio DAbrusco Lorena Travaglini Valentina Serpieri Sabrina Signorini Chiara Aiello Enrico Bertini Maria Teresa Bassi Enza Maria Valente Ginevra Zanni Renato Borgatti Filippo Arrigoni 《International journal of molecular sciences》2022,23(12)
The inositol 1,4,5-triphosphate receptor type 1 (ITPR1) gene encodes an InsP3-gated calcium channel that modulates intracellular Ca2+ release and is particularly expressed in cerebellar Purkinje cells. Pathogenic variants in the ITPR1 gene are associated with different types of autosomal dominant spinocerebellar ataxia: SCA15 (adult onset), SCA29 (early-onset), and Gillespie syndrome. Cerebellar atrophy/hypoplasia is invariably detected, but a recognizable neuroradiological pattern has not been identified yet. With the aim of describing ITPR1-related neuroimaging findings, the brain MRI of 14 patients with ITPR1 variants (11 SCA29, 1 SCA15, and 2 Gillespie) were reviewed by expert neuroradiologists. To further evaluate the role of superior vermian and hemispheric cerebellar atrophy as a clue for the diagnosis of ITPR1-related conditions, the ITPR1 gene was sequenced in 5 patients with similar MRI pattern, detecting pathogenic variants in 4 of them. Considering the whole cohort, a distinctive neuroradiological pattern consisting in superior vermian and hemispheric cerebellar atrophy was identified in 83% patients with causative ITPR1 variants, suggesting this MRI finding could represent a hallmark for ITPR1-related disorders. 相似文献
2.
Generalized processor sharing (GPS) is a fluid scheduling policy providing perfect fairness over both constant-rate and variable-rate links. The minimum deviation (lead/lag) with respect to the GPS service achievable by a packet scheduler is one maximum packet size. To the best of our knowledge, the only packet scheduler guaranteeing the minimum deviation is worst-case fair weighted fair queueing , which requires on-line GPS simulation. Existing algorithms to perform GPS simulation have worst-case computational complexity per packet transmission (being the number of competing flows). Hence, has been charged for complexity too. However it has been proven that the lower bound complexity to guarantee deviation is, yet a scheduler achieving such a result has remained elusive so far. In this paper, we present L-GPS, an algorithm that performs exact GPS simulation with worst-case complexity and small constants. As such it improves the complexity of all the packet schedulers based on GPS simulation. We also present , an implementation of based on L-GPS. has complexity with small constants, and, since it achieves the minimum possible deviation, it does match the aforementioned complexity lower bound. Furthermore, both L-GPS and comply with constant-rate as well as variable-rate links. We assess the effectiveness of both algorithms by simulating real-world scenarios. 相似文献
3.
S.E. Kanellopoulos L.C.G. Valente V.A. Handerek A.J. Rogers 《Photonics Technology Letters, IEEE》1991,3(9):806-809
Photorefractive polarization couplers written internally in germanium-doped elliptical core fibers at 488, 514, and 532 nm are reported. Complete power transfer between the orthogonal polarization modes of the fiber was achieved for couplers written at 514 and 488 nm, respectively. It is shown that the couplers are nonuniform in length because of the high photoinduced attenuation and also due to two-photon absorption. Polarization coupling of higher order modes is also demonstrated at shorter wavelengths where their polarization beat lengths match the polarization beat length of the fundamental mode at which the coupler was written.<> 相似文献
4.
F. La Via G. Galvagno F. Giannazzo A. Ruggiero L. Calcagno M. Mauceri G. Pistone G. Abbondanza A. Veneroni L. Zamolo G.L. Valente 《Microelectronic Engineering》2006,83(1):48-50
The results of a new epitaxial process using an industrial 6 × 2″ wafer reactor with the introduction of HCl during the growth have been reported. A complete reduction of silicon nucleation in the gas phase has been observed even for high silicon dilution parameters (Si/H2 > 0.05%) and an increase of the growth rate until about 20 μm/h has been measured. Photoluminescence at room temperature and at 50 K was used for defects quantification and distribution. On these wafers grown using HCl high voltage Schottky diodes have been realized. The diodes were analyzed by current-voltage (I-V) characteristics. 相似文献
5.
Marta Abrantes Maria Salete Balula Anabela A. Valente Filipe A. Almeida Paz Martyn Pillinger Carlos C. Romão João Rocha Isabel S. Gonçalves 《Journal of Inorganic and Organometallic Polymers and Materials》2007,17(1):215-222
The organotin vanadate [Me3SnVO3] (1) has been prepared and characterised in the solid state by powder X-ray diffraction (XRD), thermogravimetric analysis, multinuclear
magic-angle spinning (MAS) NMR, IR and Raman spectroscopy. The phase purity and structure of microcrystalline 1 were confirmed by carrying out a full Rietveld structural refinement at ambient temperature and from conventional powder
XRD. 51V and 119Sn MAS NMR data for compound 1 were in agreement with the predicted structure, showing two equally-abundant, nonequivalent Me3Sn groups and two equally-abundant, nonequivalent vanadium atoms. The compound was applied as a catalyst for the liquid-phase
epoxidation of olefins at 55 °C using tert-butyl hydroperoxide (tBuOOH) as the oxidant. The reaction rate for the different substrates followed the order cis-cyclooctene > (R)-(+)-limonene ≅ trans-2-octene > cyclododecene > styrene > 1-octene; the corresponding epoxides were the
only observed products. Leaching tests indicated that the catalytic epoxidation of cyclooctene was mainly heterogeneous in
nature.
This paper is dedicated to Professor Ian Manners and his scientific accomplishments. 相似文献
6.
G. Pacheco-Malagn Norma. A. Sanchez-Flores J. Saniger-Blesa L. Baos P. Prez-Romo Jaime S. Valente Mara de L. Guzman-Castillo F. Hernndez-Beltrn Jos J. Fripiat 《Microporous and mesoporous materials》2007,100(1-3):70-76
This contribution deals with the synthesis of a silicon-rich ZSM-5 obtained from an amorphous organo-alumino-silicic gel. The gel was formed by reacting a mechanical mixture of RHA (rice hull ash), silica’s source, and of natural clinoptilolite, source of alumina, with glycerol during 2 h at 200 °C. After a maturation period of one day at 60 °C, the reaction product was hydrolyzed by a tetra-propyl-ammonium (TPA) solution and then aged for two days at 135 °C in a stainless steel autoclave. After washing and drying, the X-ray pattern showed a well crystallized ZSM-5. The textural analysis of the slowly calcined solid at 500 °C for 4 h, and the SEM micrographies evidence that the zeolite was supported on mesoporous silica. The proportion of both components depends on the tunable hydrolysis conditions. 相似文献
7.
Liliana Martelo Alfonso Jiménez Artur JM Valente Hugh D Burrows Ana T Marques Michael Forster Ullrich Scherf Mercedes Peltzer Sofia M Fonseca 《Polymer International》2012,61(6):1023-1030
Films of neat and plasticized biodegradable poly(lactic acid) (PLA) matrices containing anionic conjugated polyelectrolytes, poly[9,9‐bis(4‐phenoxybutylsulfonate)]fluorene‐2,7‐diyl‐alt‐arylenes, with 1,4‐phenylene and 4,4″‐p‐terphenylene, respectively, as arylene groups or a neutral poly(9,9‐dialkylfluorene) for comparison were prepared by solution casting. These films were characterized using differential scanning calorimetry, thermogravimetry, scanning electron microscopy and fluorescence spectroscopy. In addition, the effects of plasticizer on the thermal properties and the oxygen permeability of the PLA films were measured through the oxygen transmission rate. Results show that it is possible to obtain thin, optically transparent and luminescent films with potential in oxygen sensing, exhibiting good thermal and photochemical stability. At high polyelectrolyte content, evidence is found for phase separation and aggregate formation and it is no longer possible to obtain completely homogeneous films. The possibility of incorporating the cationic metal complex tris(2,2′‐bipyridyl)ruthenium(II) into plasticized PLA films containing conjugated polyelectrolytes for dual‐wavelength ratiometric luminescence sensing is also discussed. Copyright © 2012 Society of Chemical Industry 相似文献
8.
Patricia Garrido-Pascual Ana Alonso-Varona Begoa Castro María Burn Teodoro Palomares 《International journal of molecular sciences》2020,21(24)
Oxidative stress associated with neuroinflammation is a key process involved in the pathophysiology of neurodegenerative diseases, and therefore, has been proposed as a crucial target for new therapies. Recently, the therapeutic potential of human adipose-derived stem cells (hASCs) has been investigated as a novel strategy for neuroprotection. These cells can be preconditioned by exposing them to mild stress in order to improve their response to oxidative stress. In this study, we evaluate the therapeutic potential of hASCs preconditioned with low doses of H2O2 (called HC016 cells) to overcome the deleterious effect of oxidative stress in an in vitro model of oligodendrocyte-like cells (HOGd), through two strategies: i, the culture of oxidized HOGd with HC016 cell-conditioned medium (CM), and ii, the indirect co-culture of oxidized HOGd with HC016 cells, which had or had not been exposed to oxidative stress. The results demonstrated that both strategies had reparative effects, oxidized HC016 cell co-culture being the one associated with the greatest recovery of the damaged HOGd, increasing their viability, reducing their intracellular reactive oxygen species levels and promoting their antioxidant capacity. Taken together, these findings support the view that HC016 cells, given their reparative capacity, might be considered an important breakthrough in cell-based therapies. 相似文献
9.
A. Ya. Polishchuk A. J. M. Valente G. Camino M. P. Luda N. N. Madyuskin V. M. M. Lobo G. E. Zaikov M. Revellino 《应用聚合物科学杂志》2002,83(5):1157-1166
Engineering materials containing poly(vinyl acetate) (PVAc) as the key component undergo hydrolytic degradation, which must be minimized or, at least, controlled. To characterize PVAc hydrolysis quantitatively, the diffusion of acetic acid (HAc) in PVAc, poly(vinyl alcohol) (PVA), unsaturated polyester (UPE), and a UPE/PVAc blend was studied in detail. The permeability cell earlier developed by the authors was modified here to reduce experimental error. As the diffusion and solubility coefficients of water and HAc in the above materials were measured at different temperatures, a mathematical model was developed, which takes proper account of the combined water and HAc diffusion in PVAc undergoing partial hydrolysis. The model was further validated by the experimental data obtained at 70°C for UPE/PVAc film, simulating a matrix of sheet‐molding compounds composite materials. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1157–1166, 2002 相似文献
10.
Pyrolysis of sugarcane bagasse in a fixed bed reactor: Influence of operational conditions in the distribution of products 下载免费PDF全文