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821.
Sudheer Jawla Qing Zhe Ni Alexander Barnes William Guss Eugenio Daviso Judith Herzfeld Robert Griffin Richard Temkin 《Journal of Infrared, Millimeter and Terahertz Waves》2013,34(1):42-52
In this paper, we describe the design and experimental results from the rebuild of a 250 GHz gyrotron used for Dynamic Nuclear Polarization enhanced Nuclear Magnetic Resonance spectroscopy on a 380 MHz spectrometer. Tuning bandwidth of approximately 2 GHz is easily achieved at a fixed magnetic field of 9.24 T and a beam current of 95 mA producing an average output power of >10 W over the entire tuning band. This tube incorporates a double disk output sapphire window in order to maximize the transmission at 250.58 GHz. DNP Signal enhancement of >125 is achieved on a 13C-Urea sample using this gyrotron. 相似文献
822.
Gianfranco Fornaro Antonio Pauciullo Eugenio Sansosti 《IEEE transactions on image processing》2005,14(7):960-972
This work addresses the derivation of the phase difference-based maximum likelihood (ML) phase unwrapping algorithm. To this end, we derive the joint statistics of the phase differences on a two-dimensional grid for the multichannel case, where several scaled wrapped phase values are available. Subsequently, we determine and study the structure of the phase difference-based ML estimator and compare it to known phase unwrapping techniques. This work allows us to frame single and multichannel algorithms in a common formulation. Moreover, among the known single-channel phase difference-based procedures, we identify those attaining an ML solution. We also show that multichannel phase difference-based and, recently proposed, phase-based ML algorithms achieve equivalent solutions. 相似文献
823.
Eugenio Molina‐Navarro Silvia Martínez‐Perez Antonio Sastre‐Merlín 《Lakes & Reservoirs: Research and Management》2017,22(2):134-147
Large reservoirs in the Mediterranean area exhibit a variety of negative impacts resulting from exploitation of their water, many a result of large water‐level fluctuations. Water managers in Spain have implemented various mitigation measures to reduce these negative impacts. One such measure is construction of small dams in the riverine zone of large reservoirs to create a small waterbody with a constant water level (i.e. a ‘limno‐reservoir’) to provide the environmental and recreational services that the main reservoir cannot provide due to water‐level variations. To this end, the Pareja Limno‐reservoir was built in 2006 in a sidearm of the Entrepeñas Reservoir (Guadalajara, central Spain). As its environmental sustainability was not assessed prior to construction, however, there are some uncertainties about the ability of the limno‐reservoir to provide the expected environmental and recreational services. Accordingly, a multidisciplinary study was conducted on the Pareja Limno‐reservoir to shed on its environmental sustainability. This study addressed three relevant issues associated with the limno‐reservoir, focusing on water availability, water quality and the risk of sediment filling. This study reviews the research conducted to date, including an integrative discussion that endeavours to address these issues. The Pareja Limno‐reservoir is currently a successful tourist and recreational aquatic resource. The results of this study, however, reveal its recreational and environmental value may be reduced, especially as a constant water level at the maximum capacity of the limno‐reservoir cannot be guaranteed. The conclusions of this study may be useful for reservoir managers by providing guidelines for assessing the environmental sustainability of limno‐reservoirs. 相似文献
824.
J. L. Ponz‐Tienda A. Salcedo‐Bernal Eugenio Pellicer 《Computer-Aided Civil and Infrastructure Engineering》2017,32(6):474-498
The efficient use of resources is a key factor to minimize the cost while meeting time deadlines and quality requirements; this is especially important in construction projects where field operations make fluctuations of resources unproductive and costly. Resource Leveling Problems (RLP) aim to sequence the construction activities that maximize the resource consumption efficiency over time, minimizing the variability. Exact algorithms for the RLP have been proposed throughout the years to offer optimal solutions; however, these problems require a vast computational capability (“combinatorial explosion”) that makes them unpractical. Therefore, alternative heuristic and metaheuristic algorithms have been suggested in the literature to find local optimal solutions, using different libraries to benchmark optimal values; for example, the Project Scheduling Problem LIBrary for minimal lags is still open to be solved to optimality for RLP. To partially fill this gap, the authors propose a Parallel Branch and Bound algorithm for the RLP with minimal lags to solve the RLP with an acceptable computational effort. This way, this research contributes to the body of knowledge of construction project scheduling providing the optimums of 50 problems for the RLP with minimal lags for the first time, allowing future contributors to benchmark their heuristics methods against exact results by obtaining the distance of their solution to the optimal values. Furthermore, for practitioners, the time required to solve this kind of problem is reasonable and practical, considering that unbalanced resources can risk the goals of the construction project. 相似文献
825.
Anna M. Gueli Eugenio Pedullà Stefania Pasquale Giusy R. La Rosa Ernesto Rapisarda 《Color research and application》2017,42(5):684-692
Accurate color reproduction in conservative dentistry is fundamental to the aesthetic success of the restorations. The need to specify the color objectively has been known for some years, and this article aims to make a contribution to this field. This work is part of a multidisciplinary research project, and it has a double aim. The first purpose was to measure the color differences between the two new composite resin restorative materials and the most used dental color scale. Measurements show some differences from color shades indicated by the manufacturers and those obtained from experimental data. The influence of different order of enamel and dentin layers on color perception was also investigated to evaluate clinical strategies useful to obtain desired result. Relevant differences are observed in the stratification of dentin and enamel discs especially for one of the two studied composites. 相似文献
826.
Juan Pablo Prieto‐Ruiz Sara Gmez Miralles Helena Prima‐García Angel Lpez‐Muoz Alberto Riminucci Patrizio Graziosi Martin Aeschlimann Mirko Cinchetti Valentin Alek Dediu Eugenio Coronado 《Advanced materials (Deerfield Beach, Fla.)》2019,31(10)
The quest for a spin‐polarized organic light‐emitting diode (spin‐OLED) is a common goal in the emerging fields of molecular electronics and spintronics. In this device, two ferromagnetic (FM) electrodes are used to enhance the electroluminescence intensity of the OLED through a magnetic control of the spin polarization of the injected carriers. The major difficulty is that the driving voltage of an OLED device exceeds a few volts, while spin injection in organic materials is only efficient at low voltages. The fabrication of a spin‐OLED that uses a conjugated polymer as bipolar spin collector layer and ferromagnetic electrodes is reported here. Through a careful engineering of the organic/inorganic interfaces, it is succeeded in obtaining a light‐emitting device showing spin‐valve effects at high voltages (up to 14 V). This allows the detection of a magneto‐electroluminescence (MEL) enhancement on the order of a 2.4% at 9 V for the antiparallel (AP) configuration of the magnetic electrodes. This observation provides evidence for the long‐standing fundamental issue of injecting spins from magnetic electrodes into the frontier levels of a molecular semiconductor. The finding opens the way for the design of multifunctional devices coupling the light and the spin degrees of freedom. 相似文献
827.
Danny Eugenio García Juan Pablo Salazar Sebastian Riquelme Nacarid Delgado Sebastian Paczkowski 《Polymer-Plastics Technology and Engineering》2018,57(8):709-726
Novel polylactic acid-based composites were prepared for the first time by melt-blending urethanization using bark polyflavonoids, and polymeric methyl diisocyanate. Rheological, morphological, structural, thermal, and mechanical properties were studied. Polymerization between polyflavonoids and isocyanate during the melt-blending was demonstrated by spectroscopy, confocal microscopy, and thermal analysis. Polyflavonoids improved the blend processability and affected the polylactic acid-crystallization, blend-urethanization, and flexural features. Polyphenols act as nucleating agent, and the effect was highly influenced by the polymeric methyl diisocyanate-charge, and the polyflavonoids-content. Low polymeric methyl diisocyanate-loading (10?wt%) degrades the elasticity modulus (E), while the highest polymeric (20 wt%) improved the miscibility between the polylactic acid polymer-matrix and the polyflavonoids. 相似文献
828.
829.
Zaira Gonzlez-Snchez Victoria Areal-Quecuty Alvaro Jimenez-Guerra Daniel Cabanillas-Balsera Francisco Javier Gil Eugenio Velasco-Ortega David Pozo 《International journal of molecular sciences》2022,23(8)
Most of the research on titanium-based dental implants (Ti-discs) is focused on how they are able to stimulate the formation of new tissue and/or cytotoxic studies, with very scarce data on their effects on functional responses by immunocompetent cells. In particular, the link between the rewiring of innate immune responses and surface biomaterials properties is poorly understood. To address this, we characterize the functional response of macrophage cultures to four different dental titanium surfaces (MA: mechanical abrasion; SB + AE: sandblasting plus etching; SB: sandblasting; AE: acid etching). We use different Toll-like receptor (TLR) ligands towards cell surface receptors (bacterial lipopolysaccharide LPS for TLR4; imiquimod for TLR7; synthetic bacterial triacylated lipoprotein for TLR2/TLR1) and endosomal membrane receptor (poly I:C for TLR3) to simulate bacterial (cell wall bacterial components) or viral infections (dsRNA and ssRNA). The extracellular and total LDH levels indicate that exposure to the different Ti-surfaces is not cytotoxic for macrophages under resting or TLR-stimulated conditions, although there is a tendency towards an impairment in macrophage proliferation, viability or adhesion under TLR4, TLR3 and TLR2/1 stimulations in SB discs cultures. The secreted IL-6 and IL-10 levels are not modified upon resting macrophage exposure to the Ti-surfaces studied as well as steady state levels of iNos or ArgI mRNA. However, macrophage exposure to MA Ti-surface do display an enhanced immune response to TLR4, TLR7 or TLR2/1 compared to other Ti-surfaces in terms of soluble immune mediators secreted and M1/M2 gene expression profiling. This change of characteristics in cellular phenotype might be related to changes in cellular morphology. Remarkably, the gene expression of Tlr3 is the only TLR that is differentially affected by distinct Ti-surface exposure. These results highlight the relevance of patterned substrates in dental implants to achieve a smart manipulation of the immune responses in the context of personalized medicine, cell-based therapies, preferential lineage commitment of precursor cells or control of tissue architecture in oral biology. 相似文献
830.
Pawe&#x; A. Grze Bonifacio Monti Natalia Wawrusiewicz-Kurylonek Luana Bagnoli Luca Sancineto Izabella Jastrzebska Claudio Santi 《International journal of molecular sciences》2022,23(6)
Here we report the reaction in the biphasic system of the in situ prepared selenols and thiols with 1,4-androstadiene-3,17-dione (1) or prednisone acetate (2) having α,β-unsaturated ketone as an electrophilic functionalization. The Michael-type addition reaction resulted to be chemo- and stereoselective, affording a series of novel steroidal selenides and sulfides. This is an example of a one-step, eco-friendly process that bypasses some of the main concerns connected with the bad smell and the toxicity of these seleno- and thio-reagents. Furthermore, we demonstrated that the proposed methodology offers the possibility to prepare libraries of steroids variously and selectively decorated with different organochalcogen moieties at the C1 position starting from 1,4-androstadienic skeletons and leaving unaltered the C4–C5 unsaturation. Based on the data reported in the literature the introduction of an organoselenium or an organosulfur moiety in a steroid could provide new interesting pharmaceutically active entities exerting anticancer and antimicrobial activities. In this optic, new synthetic strategies to efficiently prepare this class of compounds could be strongly desirable. 相似文献