2,518 research outputs found
Structural studies of mesoporous ZrO-CeO and ZrO-CeO/SiO mixed oxides for catalytical applications
In this work the synthesis of ZrO-CeO and
ZrO-CeO/SiO were developed, based on the process to form
ordered mesoporous materials such as SBA-15 silica. The triblock copolymer
Pluronic P-123 was used as template, aiming to obtain crystalline single phase
walls and larger specific surface area, for future applications in catalysis.
SAXS and XRD results showed a relationship between ordered pores and the
material crystallization. 90% of CeO leaded to single phase homogeneous
ceria-zirconia solid solution of cubic fluorite structure (Fmm). The
SiO addition improved structural and textural properties as well as the
reduction behavior at lower temperatures, investigated by XANES measurements
under H atmosphere
Simultaneous Measurement of Changes in Thickness and Refractive Index of Weakly Absorbing Self-Standing Solid Films Using Optical Interferometry
A nondestructive optical interferometric method, which enables a direct and simultaneous measurement of small changes in both thickness and refractive index of thin films, is described. Optical interferometric methods are sensitive to the changes in the optical path length (the product of the refractive index and the physical thickness) through the film. Thus, when the film is subjected to changing environmental conditions such as changing temperature or humidity, it is a challenge to determine the change in thickness and the change in refractive index separately, using interferometry. By simultaneously monitoring two different sets of interference fringes, i.e., transmission and reflection fringes, we have been able to successfully address this challenge. Our measurements on well-characterized pedigree glass samples are presented. The results agree well with the expected values for these samples, supporting the feasibility of this characterization technique to new materials. Self-standing, transparent (weakly absorbing) films ranging in thickness from tens to hundreds of microns can be characterized from direct measurements
Spectral and Spatial Dependence of Diffuse Optical Signals in Response to Peripheral Nerve Stimulation
Using non-invasive, near-infrared spectroscopy we have previously reported optical signals measured at or around peripheral nerves in response to their stimulation. Such optical signals featured amplitudes on the order of 0.1% and peaked about 100 ms after peripheral nerve stimulation in human subjects. Here, we report a study of the spatial and spectral dependence of the optical signals induced by stimulation of the human median and sural nerves, and observe that these optical signals are: (1) unlikely due to either dilation or constriction of blood vessels, (2) not associated with capillary bed hemoglobin, (3) likely due to blood vessel(s) displacement, and (4) unlikely due to fiber-skin optical coupling effects. We conclude that the most probable origin of the optical response to peripheral nerve stimulation is from displacement of blood vessels within the optically probed volume, as a result of muscle twitch in adjacent areas.National Institutes of Health (R01-NS059933); U.S. Army Medical Acquisition Activity (W81XWH-07-2-0011
Implementation of Deep-Learning-Based CSI Feedback Reporting on 5G NR-Compliant Link-Level Simulator
Advances in machine learning have widened the range of its applications in many fields. In particular, deep learning has attracted much interest for its ability to provide solutions where the derivation of a rigorous mathematical model of the problem is troublesome. Our interest was drawn to the application of deep learning for channel state information feedback reporting, a crucial problem in frequency division duplexing (FDD) 5G networks, where knowledge of the channel characteristics is fundamental to exploiting the full potential of multiple-input multiple-output (MIMO) systems. We designed a framework adopting a 5G New Radio convolutional neural network, called NR-CsiNet, with the aim of compressing the channel matrix experienced by the user at the receiver side and then reconstructing it at the transmitter side. In contrast to similar solutions, our framework is based on a 5G New Radio fully compliant simulator, thus implementing a channel generator based on the latest 3GPP 3-D channel model. Moreover, realistic 5G scenarios are considered by including multi-receiving antenna schemes and noisy downlink channel estimation. Simulations were carried out to analyze and compare the performance with current feedback reporting schemes, showing promising results for this approach from the point of view of the block error rate and throughput of the 5G data channel
Cost-of-illness in systemic sclerosis: a retrospective study of an italian cohort of 106 patients
Aims: It is increasingly important to determine the economic consequences of diseases considering the policy of limited health–care budgets. In this study we evaluated the annual direct and indirect costs of Systemic Sclerosis (SSc) and we tried also to identify any cost predictors. Methods: We studied 106 patients (103 female, 3 male), 57 affected by Limited Systemic Sclerosis (LSSc) and 49 affected by Diffuse Systemic Sclerosis (DSSc). Mean age was 57 years (SD±13,8) and mean disease duration was 8,9 years (SD±7,2). Direct costs: data were calculated referring to DRG (Disease Related Group) expenses for the in-patients. We referred to national pharmacopoeia to calculate the pharmaceutical cost for the out-patients. Indirect costs: we estimated the expense comparing our cases to literature data. Intangible costs: these are attributable to pain and psychological suffering. It is very difficult to express the intangible costs in monetary terms and they are often conveyed as disability and poorer quality-of-life. We used the Health Assessment Questionnaire "HAQ" and the Short Form-36 "SF-36" to evaluate this issues. Results: Our study confirms, the extremely high costs caused by Systemic Sclerosis (total cost's 2001 year is € 1.173.842,93, and average yearly patient cost is € 11.073,99). Considering an estimated prevalence of 375 cases/106, the total yearly economic impact of SSc in Italy should be € 249.000.000,00. Intangible costs were calculated as modifications of the health status. Average value of the HAQ was significantly higher than the control population (0,94±0,72), average values in the SF-36 were significantly lower than the control population (49,99±19,16 for physical dimension and 58,42±27,71 for mental dimension). The diffuse form of SSc, positivity for anti-Scl 70 antibodies, high skin score and a poor health status (HAQ and SF-36) were found to be cost predictors. Conclusions: As reported in the literature, our study confirms, the extremely high costs for total and single patients caused by Systemic Sclerosis. The DSSc are more expensive than the LSSc approximately 11% (p=0,0067). The direct costs are 30% higher in the DSSc than the LSSc (p<0.001). The indirect and intangible costs are not significantly different. Moreover, our study shows also the possibility of identifying different cost predictors
Secondary forest succession in the Mata Atlantica, Brazil: floristic and phytosociological trends.
This study aimed at understanding the dynamics of ecological processes and the use of secondary forests in Santa Catarina state (Brazil). The data base for these studies was formed through forest inventories carried out in the three forest types of the state. The results of this study demonstrate that the patterns of diversity are very similar among the three forest types; however, the species compositions among the types are quite different. A total of 343 woody species belonging to 73 families were found in the 24,000 m2 sampling area, revealing the potential role of secondary forest in the conservation of biodiversity at the landscape scale. As expected, a small set of pioneer species dominates young secondary forests with shade-tolerant species becoming structurally important after 30 years. The patterns of forest structure and species diversity observed in study largely conform to the postagricultural secondary succession observed for many tropical forests.Article ID 759893
The encaged lung: rapidly progressive idiopathic pleurisy.
Here we present a case of an idiopathic fibrinous pleurisy affecting a 56-year old non-smoker male that has shown a rapidly progressive course. With a brief review of the literature we discuss the absence of any identified cause of pleurisy as a relatively common condition, requiring attention and clinical awareness
Field reliability of GaAs emitters for fiber optic telecommunication systems
GaAs based emitters are widely used in telecommunication systems, and will be probably the core of short haul communications, even if a lot of doubts still exist on their reliability and the few available field results are not too optimistic. For these reasons we decided to follow with a particular attention all the problems related to these devices, investigating reliability by means of accelerated tests and of an accurate survey of field troubles. In this paper, we first of all report our field data, coming from more than five years experience, which show that "reasonable" results (in the range of 2000 FITs for LDs), can be obtained with commercially available devices; as a second step, failure analysis allows to localize failures,thus understanding the appropriate corrective actions to be taken. highlighting the specific process report also same For chip related failures, detailed examples are reported, different failure mechanisms, that, when not related to defects, are the same found during accelerated tests; we examples of failures due to interconnections and packaging
In vitro and in vivo inhibition of breast cancer cell growth by targeting the Hedgehog/GLI pathway with SMO (GDC-0449) or GLI (GANT-61) inhibitors.
Aberrant Hedgehog (Hh)/glioma-associated oncogene (GLI) signaling has
been implicated in cancer progression. Here, we analyzed GLI1, Sonic Hedgehog
(Shh) and NF-κB expression in 51 breast cancer (ductal carcinoma) tissues using
immunohistochemistry. We found a positive correlation between nuclear GLI1
expression and tumor grade in ductal carcinoma cases. Cytoplasmic Shh staining
significantly correlated with a lower tumor grade. Next, the in vitro effects of two
Hh signaling pathway inhibitors on breast cancer cell lines were evaluated using the
Smoothened (SMO) antagonist GDC-0449 and the direct GLI1 inhibitor GANT-61.
GDC-0449 and GANT-61 exhibited the following effects: a) inhibited breast cancer
cell survival; b) induced apoptosis; c) inhibited Hh pathway activity by decreasing
the mRNA expression levels of GLI1 and Ptch and inhibiting the nuclear translocation
of GLI1; d) increased/decreased EGFR and ErbB2 protein expression, reduced p21-
Ras and ERK1/ERK2 MAPK activities and inhibited AKT activation; and e) decreased
the nuclear translocation of NF-κB. However, GANT-61 exerted these effects more
effectively than GDC-0449. The in vivo antitumor activities of GDC-0449 and GANT-
61 were analyzed in BALB/c mice that were subcutaneously inoculated with mouse
breast cancer (TUBO) cells. GDC-0449 and GANT-61 suppressed tumor growth of
TUBO cells in BALB/c mice to different extents. These findings suggest that targeting
the Hh pathway using antagonists that act downstream of SMO is a more efficient
strategy than using antagonists that act upstream of SMO for interrupting Hh signaling
in breast cancer
Strategies to prevent the presence of a dominant follicle (DF) between days 15 and 20 of the cow estrous cycle.
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