453 research outputs found
Design, processing and testing of LSI arrays, hybrid microelectronics task
Mathematical cost models previously developed for hybrid microelectronic subsystems were refined and expanded. Rework terms related to substrate fabrication, nonrecurring developmental and manufacturing operations, and prototype production are included. Sample computer programs were written to demonstrate hybrid microelectric applications of these cost models. Computer programs were generated to calculate and analyze values for the total microelectronics costs. Large scale integrated (LST) chips utilizing tape chip carrier technology were studied. The feasibility of interconnecting arrays of LSU chips utilizing tape chip carrier and semiautomatic wire bonding technology was demonstrated
Transcriptional control of the B3GALT5 gene by a retroviral promoter and methylation of distant regulatory elements
We focused on transcription factors and epigenetic marks that regulate the B3GALT5 gene through its retroviral long terminal repeat (LTR) promoter. We compared the expression levels of the B3GALT5 LTR transcript, quantitated by competitive RT-PCR, with those of the candidate transcription factors HNF1\u3b1/\u3b2 and Cdx1/2, determined by Western blot analysis, in colon cancer biopsies, various cell lines, and cell models serving as controls. We found that HNF1\u3b1/\u3b2 were easily detected, irrespective of the amount of LTR transcript expressed by the source, whereas Cdx1/2 were undetectable, and no sample lacking HNF1\u3b1/\u3b2 expressed the LTR transcript. On transfection in proper host cells, both HNF1\u3b1 and HNF1\u3b2 provided detectable LTR transcript, whereas shRNA-mediated silencing of HNF1\u3b2 impaired transcription. Treating cells with 5\u2032-aza-2\u2032-deoxycytidine (5AZA) strongly reduced expression, without affecting HNF1\u3b1/\u3b2, despite the lack of CpG islands in the LTR and proximal sequences. By electrophoresis mobility shift and luciferase reporter assays, the LTR promoter binding and activity did not correlate with the amounts of LTR transcript expressed in the cells and depended on the levels of the transcription factors. We conclude that HNF1\u3b1/\u3b2 are necessary but insufficient to activate and regulate B3GALT5 LTR transcription, which depends on unknown regulatory elements that are active when methylated and located outside of and far from the LTR promoter
Radiologic features of small pulmonary nodules detected in initially negative screening CT examinations: a step towards personalized screening strategies?
Results of the National Lung Screening Trial (NLST)
have invigorated the discussion around performing lung
cancer screening using low-dose computed tomography
(LDCT) of the chest. The NLST trial demonstrated a
clear benefit of LDCT screening in reducing lung cancer
and all-cause mortality, by showing reduced lung cancer
mortality in high-risk individuals by about 20%, and allcause mortality by 6.7%, compared to a control group of
subjects receiving chest radiographs
Spatial Mapping and Modeling of Reported Dengue Incidences in Luzon
Dengue, the most rapidly spreading mosquito-borne viral infection, has significantly spread worldwide in recent decades - flourishing both in affluent and impoverished locations of tropical and subtropical countries. In 2012, the Philippines ranked fourth out of the ten Association of the Southeast Asian Nations (ASEAN) countries in having the highest number of dengue cases. The following study intends to analyze the spatial distribution of dengue incidences across all Luzon provinces in 2018. It aims to determine significant correlates that affect dengue incidences, map the incidence rate of dengue cases, and explore the clustering of recorded dengue cases. Poisson and Negative Binomial (NB) regression analyses and Multiple Linear Regression Models (MLRM) were applied to determine the significant correlations affecting dengue incidence rates. Simultaneously, spatial mapping was utilized to visualize and detect clustering in the provinces through dengue count, incidence ratios, and standard incidence ratios (SIR). MLRM and NB showed that rainfall and poverty incidence are significant correlates of dengue counts and incidence, and Nueva Ecija and Tarlac were observed to be provinces with distinct dengue count and SIR greater than 1, as well as provinces found in clusters. With the provided results, health organizations can provide health programs and allocate more funds in areas with SIR greater than 1 to prevent dengue spreading
An Innovative Lipidomic Workflow to Investigate the Lipid Profile in a Cystic Fibrosis Cell Line
Altered lipid metabolism has been associated to cystic fibrosis disease, which is characterized by chronic lung inflammation and various organs dysfunction. Here, we present the validation of an untargeted lipidomics approach based on high-resolution mass spectrometry aimed at identifying those lipid species that unequivocally sign CF pathophysiology. Of n.13375 mass spectra recorded on cystic fibrosis bronchial epithelial airways epithelial cells IB3, n.7787 presented the MS/MS data, and, after software and manual validation, the final number of annotated lipids was restricted to n.1159. On these lipids, univariate and multivariate statistical approaches were employed in order to select relevant lipids for cellular phenotype discrimination between cystic fibrosis and HBE healthy cells. In cystic fibrosis IB3 cells, a pervasive alteration in the lipid metabolism revealed changes in the classes of ether-linked phospholipids, cholesterol esters, and glycosylated sphingolipids. Through functions association, it was evidenced that lipids variation involves the moiety implicated in membrane composition, endoplasmic reticulum, mitochondria compartments, and chemical and biophysical lipids properties. This study provides a new perspective in understanding the pathogenesis of cystic fibrosis and strengthens the need to use a validated mass spectrometry-based lipidomics approach for the discovery of potential biomarkers and perturbed metabolism
Diagnostic yield of electromagnetic navigation bronchoscopy is highly dependent on the presence of a Bronchus sign on CT imaging: results from a prospective study
Electromagnetic navigation bronchoscopy (ENB) has been developed as a
novel ancillary tool for the bronchoscopic diagnosis of pulmonary nodules.
Despite successful navigation in 90% of patients, ENB diagnostic yield does not
generally exceed 70%. We sought to determine whether the presence of a bronchus
sign on CT imaging conditions diagnostic yield of ENB and might account for the
discrepancy between successful navigation and diagnostic yield. METHODS: We
conducted a prospective, single-center study of ENB in 51 consecutive patients
with pulmonary nodules. ENB was chosen as the least invasive diagnostic technique
in patients with a high surgical risk, suspected metastatic disease, or
advanced-stage disease, or in those who demanded a preoperative diagnosis prior
to undergoing curative resection. We studied patient and technical variables that
might condition diagnostic yield, including size, cause, location, distance to
the pleural surface, and fluorodeoxyglucose uptake of a given nodule; the
presence of a bronchus sign on CT imaging; registration point divergence; and the
minimum distance from the tip of the locatable guide to the nodule measured
during the procedure. RESULTS: The diagnostic yield of ENB was 67% (34/51). The
sensitivity and specificity of ENB for malignancy in this study were 71% and
100%, respectively. ENB was diagnostic in 79% (30/38) patients with a bronchus
sign on CT imaging but only in 4/13 (31%) with no discernible bronchus sign.
Univariate analysis identified the bronchus sign (P = .005) and nodule size (P =
.04) as statistically significant variables conditioning yield, but on
multivariate analysis, only the bronchus sign remained significant (OR, 7.6; 95%
CI, 1.8-31.7). No procedure-related complications were observed. CONCLUSIONS: ENB
diagnostic yield is highly dependent on the presence of a bronchus sign on CT
imaging
Análisis multiescala de las comunidades de coral hermatÃpico del PacÃfico Central Mexicano
The Mexican Central Pacific is located in a zone of oceanographic transition between two biogeographic provinces with particular conditions that affect the associated fauna. The objective of this study was to evaluate the variation of hermatypic coral assemblages in this region and to determine their relationship with the heterogeneity of the benthonic habitat and spatial variables. A total of 156 transects were carried out at 41 sites in the years 2010 and 2011. The sampling effort returned 96.7% of the coral richness expected for the area, with a total of 15 species recorded. The results showed that richness, diversity and cover of corals varied only at the site and state scales. However, the composition and coverage of all coral species, as well as the benthonic habitat structure, differed significantly across the study scales (i.e. sites, zones and states). Canonical redundancy analysis showed that variation in the richness, diversity and assemblages of corals was explained by the cover of live corals, articulated calcareous algae, sandy substrate, sponges and fleshy macroalgae. This study suggests that local scale (i.e. site) variation in the coral assemblages of the Mexican Central Pacific is the result of the heterogeneity of the benthonic habitat, while geomorphological and oceanographic characteristics play a greater role at regional scale.El PacÃfico Central Mexicano se localiza en una zona de transición oceanográfica entre dos provincias biogeográficas con condiciones ambientales particulares que afectan la fauna asociada. El objetivo del estudio fue evaluar la variación de las comunidades de coral hermatÃpico de esta región y determinar su relación con la heterogeneidad del hábitat bentónico y variables espaciales. Se realizaron 156 transectos en 41 sitios en los años 2010 y 2011. El esfuerzo de muestreo representó el 96.7% de la riqueza de coral esperada para el área, con un total de 15 especies registradas. Los resultados mostraron que la riqueza, diversidad y cobertura de corales variaron sólo en las escalas de sitio y de estado. En cambio, la composición y cobertura de todas las especies de coral, asà como la estructura del hábitat bentónico, fueron significativamente diferentes en todas las escalas estudiadas (i.e. sitio, zona y estado). Los análisis de redundancia canónica mostraron que la variación de la riqueza, diversidad y de las comunidades de corales eran explicadas por la cobertura de coral vivo, algas calcáreas articuladas, sustrato arenoso, esponjas y macroalgas carnosas. Este trabajo sugiere que la variación de las comunidades de coral en el PacÃfico Central Mexicano a escala local (i.e. sitio) se debe a la heterogeneidad del hábitat bentónico, mientras que a escala regional, las caracterÃsticas geomorfológicas y oceanográficas desempeñan un papel más importante
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Optimization of an enclosed gas analyzer sampling system for measuring eddy covariance fluxes of H<sub>2</sub>O and CO<sub>2</sub>
Several initiatives are currently emerging to observe the exchange
of energy and matter between the earth's surface and atmosphere
standardized over larger space and time domains. For example, the
National Ecological Observatory Network (NEON) and the Integrated
Carbon Observing System (ICOS) are set to provide the ability of unbiased
ecological inference across ecoclimatic zones and decades by
deploying highly scalable and robust instruments and data
processing. In the construction of these observatories, enclosed
infrared gas analyzers are widely employed for eddy covariance
applications. While these sensors represent a substantial
improvement compared to their open- and closed-path predecessors,
remaining high-frequency attenuation varies with site properties and gas sampling systems,
and requires correction. Here, we show that components of the gas sampling system
can substantially contribute to such high-frequency attenuation, but their effects
can be significantly reduced by careful system design. From laboratory tests we determine
the frequency at which signal attenuation reaches 50 % for
individual parts of the gas sampling system. For different models
of rain caps and particulate filters, this frequency falls into
ranges of 2.5–16.5 Hz for CO2,
2.4–14.3 Hz for H2O, and 8.3–21.8 Hz for
CO2, 1.4–19.9 Hz for H2O, respectively.
AÂ short and thin stainless steel intake tube was found to not limit
frequency response, with 50 % attenuation occurring at
frequencies well above 10 Hz for both H2O and
CO2. From field tests we found that heating the intake tube
and particulate filter continuously with 4 W was effective,
and reduced the occurrence of problematic relative humidity levels
(RH  > 60 %) by 50 % in the infrared gas analyzer cell. No
further improvement of H2O frequency response was found for
heating in excess of 4 W. These laboratory and field
tests were reconciled using resistor–capacitor theory, and NEON's
final gas sampling system was developed on this basis. The design
consists of the stainless steel intake tube, a pleated mesh
particulate filter and a low-volume rain cap in combination with
4 W of heating and insulation. In comparison to the original
design, this reduced the high-frequency attenuation for H2O
by  ≈ 3∕4, and the remaining cospectral correction did not
exceed 3 %, even at high relative humidity
(95 %). The standardized design can be used across a wide range
of ecoclimates and site layouts, and maximizes practicability due
to minimal flow resistance and maintenance needs. Furthermore, due
to minimal high-frequency spectral loss, it supports the routine
application of adaptive correction procedures, and enables largely
automated data processing across sites
Emphysema presence, severity, and distribution has little impact on the clinical presentation of a cohort of patients with mild to moderate COPD
Phenotypic characterization of patients with COPD may have potential
prognostic and therapeutic implications. Available information on the
relationship between emphysema and the clinical presentation in patients with
COPD is limited to advanced stages of the disease. The objective of this study
was to describe emphysema presence, severity, and distribution and its impact on
clinical presentation of patients with mild to moderate COPD. METHODS: One
hundred fifteen patients with COPD underwent clinical and chest CT scan
evaluation for the presence, severity, and distribution of emphysema. Patients
with and without emphysema and with different forms of emphysema distribution
(upper/lower/core/peel) were compared. The impact of emphysema severity and
distribution on clinical presentation was determined. RESULTS: Fifty percent of
the patients had mild homogeneously distributed emphysema (1.84; 0.76%-4.77%).
Upper and core zones had the more severe degree of emphysema. Patients with
emphysema were older, more frequently men, and had lower FEV(1)%, higher total
lung capacity percentage, and lower diffusing capacity of the lung for carbon
monoxide. No differences were found between the clinical or physiologic
parameters of the different emphysema distributions. CONCLUSIONS: In patients
with mild to moderate COPD, although the presence of emphysema has an impact on
physiologic presentation, its severity and distribution seem to have little
impact on clinical presentation
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