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排序方式: 共有230条查询结果,搜索用时 31 毫秒
71.
Elena Yeregui Jenifer Masip Consuelo Vilads Pere Domingo Yolanda M. Pacheco Juli Blanco Josep Mallolas Vernica Alba Montserrat Vargas Graciano García-Pardo Eugnia Negredo Montserrat Olona Judit Vidal-Gonzlez Maria Peraire Anna Martí Laia Revert Frderic Gmez-Bertomeu Manuel Leal Francesc Vidal Joaquim Peraire Anna Rull 《International journal of molecular sciences》2022,23(4)
A significant proportion of people living with HIV (PLHIV) who successfully achieve virological suppression fail to recover CD4+ T-cell counts. Since adipose tissue has been discovered as a key immune organ, this study aimed to assess the role of adipokines in the HIV immunodiscordant response. This is a multicenter prospective study including 221 PLHIV starting the first antiretroviral therapy (ART) and classified according to baseline CD4+ T-cell counts/µL (controls > 200 cells/µL and cases ≤ 200 cells/µL). Immune failure recovery was considered when cases did not reach more than 250 CD4+ T cells/µL at 144 weeks (immunological nonresponders, INR). Circulating adipokine concentrations were longitudinally measured using enzyme-linked immunosorbent assays. At baseline, apelin receptor (APLNR) and zinc-alpha-2-glycoprotein (ZAG) concentrations were significantly lower in INRs than in immunological responders (p = 0.043 and p = 0.034), and they remained lower during all ART follow-up visits (p = 0.044 and p = 0.028 for APLNR, p = 0.038 and p = 0.010 for ZAG, at 48 and 144 weeks, respectively). ZAG levels positively correlated with retinol-binding protein 4 (RBP4) levels (p < 0.01), and low circulating RBP4 concentrations were related to a low CD4+ T-cell gain (p = 0.018 and p = 0.039 at 48 and 144 weeks, respectively). Multiple regression adjusted for clinical variables and adipokine concentrations confirmed both low APLNR and RBP4 as independent predictors for CD4+ T cells at 144 weeks (p < 0.001). In conclusion, low APLNR and RBP4 concentrations were associated with poor immune recovery in treated PLHIV and could be considered predictive biomarkers of a discordant immunological response. 相似文献
72.
We here propose an all-in situ method for growing vapor-liquid-solid (VLS) silicon nanowires (SiNWs) directly on SnO(2) substrates in a plasma-enhanced chemical vapor deposition system. The tin catalysts are formed by a well-controlled H(2) plasma treatment of the SnO(2) layer. The lowest temperature for the tin-catalyzed VLS SiNWs growth in a silane plasma is ~250?°C. The effects of substrate temperature and H(2) dilution of silane on the morphology and compositional evolution of the SiNWs were systematically investigated. The catalyst content in the SiNWs can be effectively controlled by the deposition temperature. Moreover, enhanced absorption (down to ~1.1?eV) is achieved due to the strong light trapping and anti-reflection effects in the straight and long tapered SiNWs. 相似文献
73.
Cristina Manresa-Yee Pere Ponsa Iosune Salinas Francisco J. Perales Francisca Negre Javier Varona 《Behaviour & Information Technology》2014,33(3):271-282
We designed and developed a vision-based computer interface which works with head movements. The system was implemented in a centre for users with cerebral palsy and they used it in contexts related with recreation or with education. During this process, it was observed that the continued use of the interface with a set of training tasks may act as a physical and cognitive rehabilitation tool and complement users’ rehabilitation therapy. We comment on five case studies of users who have worked with the interface for five months and whose qualitative outcomes, observed by the therapists who accompanied them, were positive; specifically there was improvement in work posture, head control, increased endurance, decreased involuntary movements and improved spatial orientation. The case studies also showed the need to supervise the users’ work in order to achieve these aims, along with the importance of motivation and active, voluntary participation of users in the rehabilitation process. 相似文献
74.
Pere L. Gilabert Michael E. Gadringer Gabriel Montoro Markus L. Mayer Daniel D. Silveira Eduard Bertran Gottfried Magerl 《国际射频与微波计算机辅助工程杂志》2009,19(5):583-591
This article presents a strategy for enhancing efficiency in power amplifiers (PAs) by combining digital predistortion (DPD) linearization and clipping strategies for orthogonal frequency division multiplexing signals in a WiMAX scenario. On the one hand, by reducing the peak‐to‐average power ratio of multicarrier signals using the well‐known clipping technique, it is possible to perform a more efficient PA amplification. On the other hand, nonlinear and linear distortion introduced by the PA operating close to saturation is compensated by the baseband adaptive DPD linearizer. The DPD has to counteract not only the PA nonlinear behavior, but also its dynamics. A test‐bench implementing a WiMAX transmitter was deployed to evaluate the possibilities for enhancing power efficiency while fulfilling the demanded linearity requirements. Experimental results showing the power efficiency and linearity enhancement achieved by the proposed strategy are provided. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009. 相似文献
75.
Jacint Arnau Luis Guerrero Pere Gou 《Journal of the science of food and agriculture》1997,74(2):193-198
In Spanish dry-cured ham the temperature is sometimes increased at a specific stage in order to accelerate the ageing process. In this study the effect of temperature during the final month of a 6-month process on certain physicochemical and sensorial characteristics of hams cured for different salting times was evaluated. Three salting times and three different temperatures (20, 25 and 30°C) during the last month of the process were used. Whole ham weight losses and the incidence of white film and tyrosine crystals on the cut surface were evaluated; and chemical and sensory analysis were carried out on Biceps femoris muscle. Despite reducing white film and tyrosine crystals, an increase of 2 days in salting time, had a slight effect on texture and produced an increase in the salty taste which could be regarded as excessive. Tyrosine concentration, the incidence of white film, brightness, pastiness and piquantness, all of which may negatively affect consumer acceptability, were greater in the hams with 30°C ageing temperature. © 1997 SCI. 相似文献
76.
77.
Propagation of measurement noise through backprojection reconstruction in electrical impedance tomography 总被引:2,自引:0,他引:2
A framework to analyze the propagation of measurement noise through backprojection reconstruction algorithms in electrical impedance tomography (EIT) is presented. Two measurement noise sources were considered: noise in the current drivers and in the voltage detectors. The influence of the acquisition system architecture (serial/semi-parallel) is also discussed. Three variants of backprojection reconstruction are studied: basic (unweighted), weighted and exponential backprojection. The results of error propagation theory have been compared with those obtained from simulated and experimental data. This comparison shows that the approach provides a good estimate of the reconstruction error variance. It is argued that the reconstruction error in EIT images obtained via backprojection can be approximately modeled as a spatially nonstationary Gaussian distribution. This methodology allows us to develop a spatial characterization of the reconstruction error in EIT images. 相似文献
78.
Rafa Marin-Lopez Fernando Pereñiguez-Garcia Yoshihiro Ohba Fernando Bernal-Hidalgo Antonio F. Gomez 《Mobile Networks and Applications》2010,15(3):392-412
In this paper we present an architecture for fast re-authentication, based on the use of the Kerberos protocol, which allows
the reduction in the latency introduced for an authentication process based on the Extensible Authentication Protocol (EAP) when providing network access in mobile networks. The architecture supports two modes of operation, proactive and reactive,
to reduce the latency added for the authentication processes which is required when a mobile user changes network points of
attachment. Moreover, we provide implementation details on a representative wireless testbed and obtain experimental results
from the testbed. Those results are used for simulations to evaluate the performance of the proposed architecture for different
deployment scenarios and parameters. We also provide a mathematical analysis to compute authentication delay and validate
the simulation results. Performance comparison based on the experiment, simulation and analysis show that the proposed architecture
can reduce the authentication delay, compared to other alternatives in typical deployment scenarios. 相似文献
79.
L Yu F Fortuna B O'Donnell T Jeon M Foldyna G Picardi P Roca I Cabarrocas 《Nano letters》2012,12(8):4153-4158
Silicon nanowires (SiNWs) are becoming a popular choice to develop a new generation of radial junction solar cells. We here explore a bismuth- (Bi-) catalyzed growth and doping of SiNWs, via vapor-liquid-solid (VLS) mode, to fabricate amorphous Si radial n-i-p junction solar cells in a one-pump-down and low-temperature process in a single chamber plasma deposition system. We provide the first evidence that catalyst doping in the SiNW cores, caused by incorporating Bi catalyst atoms as n-type dopant, can be utilized to fabricate radial junction solar cells, with a record open circuit voltage of V(oc) = 0.76 V and an enhanced light trapping effect that boosts the short circuit current to J(sc) = 11.23 mA/cm(2). More importantly, this bi-catalyzed SiNW growth and doping strategy exempts the use of extremely toxic phosphine gas, leading to significant procedure simplification and cost reduction for building radial junction thin film solar cells. 相似文献
80.
In constructing a model of a large twelfth century monument, we face the repair of a huge amount of small to medium-sized defects in the mesh. The total size of the mesh after registration was in the vicinity of 173M-triangles, and presented 14,622 holes of different sizes. Although other algorithms have been presented in the literature to fix these defects, in this case a fully automatic algorithm able to fix most of the defects is needed. In this paper we present the algorithms developed for this purpose, together with examples and results to measure the final surface quality. The algorithm is based on the iteration of smoothing and fitting steps on a uniform B-Spline defined on a 3D box domain bounding the hole. Tricubic and trilinear B-Splines are compared and the respective effectiveness is discussed. 相似文献