10,377 research outputs found
Transcription of brain natriuretic peptide and atrial natriuretic peptide genes in human tissues
We have compared the expression of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) genes in various human tissues using a quantitative polymerase chain reaction technique. Tissues of three human subjects, obtained at autopsy, were analyzed. BNP transcripts could be detected in the central nervous system, lung, thyroid, adrenal, kidney, spleen, small intestine, ovary, uterus, and striated muscle. ANP transcripts could also be demonstrated in various human extracardiac tissues including several endocrine organs. In all peripheral tissues, the level of both natriuretic peptide transcripts was approximately 1-2 orders of magnitude lower than in cardiac ventricular tissues. This distribution is in marked contrast to the much lower level of ANP and BNP transcripts present in extracardiac rat tissues (generally less than 1/1000 of ventricles). These data suggest differential expression of the two natriuretic peptide genes in cardiac and extracardiac tissues in man. Furthermore, the presence of local synthesis of ANP and BNP in various peripheral organs suggests paracrine and/or autocrine function of these natriuretic peptides
APMEC: An Automated Provisioning Framework for Multi-access Edge Computing
Novel use cases and verticals such as connected cars and human-robot
cooperation in the areas of 5G and Tactile Internet can significantly benefit
from the flexibility and reduced latency provided by Network Function
Virtualization (NFV) and Multi-Access Edge Computing (MEC). Existing frameworks
managing and orchestrating MEC and NFV are either tightly coupled or completely
separated. The former design is inflexible and increases the complexity of one
framework. Whereas, the latter leads to inefficient use of computation
resources because information are not shared. We introduce APMEC, a dedicated
framework for MEC while enabling the collaboration with the management and
orchestration (MANO) frameworks for NFV. The new design allows to reuse
allocated network services, thus maximizing resource utilization. Measurement
results have shown that APMEC can allocate up to 60% more number of network
services. Being developed on top of OpenStack, APMEC is an open source project,
available for collaboration and facilitating further research activities
Histogram-based models on non-thin section chest CT predict invasiveness of primary lung adenocarcinoma subsolid nodules.
109 pathologically proven subsolid nodules (SSN) were segmented by 2 readers on non-thin section chest CT with a lung nodule analysis software followed by extraction of CT attenuation histogram and geometric features. Functional data analysis of histograms provided data driven features (FPC1,2,3) used in further model building. Nodules were classified as pre-invasive (P1, atypical adenomatous hyperplasia and adenocarcinoma in situ), minimally invasive (P2) and invasive adenocarcinomas (P3). P1 and P2 were grouped together (T1) versus P3 (T2). Various combinations of features were compared in predictive models for binary nodule classification (T1/T2), using multiple logistic regression and non-linear classifiers. Area under ROC curve (AUC) was used as diagnostic performance criteria. Inter-reader variability was assessed using Cohen's Kappa and intra-class coefficient (ICC). Three models predicting invasiveness of SSN were selected based on AUC. First model included 87.5 percentile of CT lesion attenuation (Q.875), interquartile range (IQR), volume and maximum/minimum diameter ratio (AUC:0.89, 95%CI:[0.75 1]). Second model included FPC1, volume and diameter ratio (AUC:0.91, 95%CI:[0.77 1]). Third model included FPC1, FPC2 and volume (AUC:0.89, 95%CI:[0.73 1]). Inter-reader variability was excellent (Kappa:0.95, ICC:0.98). Parsimonious models using histogram and geometric features differentiated invasive from minimally invasive/pre-invasive SSN with good predictive performance in non-thin section CT
Thoracoscopic Thoracic Duct Ligation for Persistent Cervical Chyle Leak: Utility of Immediate Pathologic Confirmation
ObjectiveChylous fistulas can occur after neck surgery. Both nonoperative measures and direct fistula ligation may lead to fistula resolution. However, a refractory fistula requires upstream thoracic duct ligation. This can be accomplished minimally invasively. Success depends on lymphatic flow interruption where the duct enters the thorax. We report on the utility of frozen section confirmation in achieving this goal.MethodsPersistent chylous fistulas occurred in 2 patients after left cervical operations. In the first patient, attempted direct fistula ligation and sclerosant application failed. Fasting, parenteral nutrition, and somatostatin-analog provided no benefit. For the second patient, nonoperative treatment was also ineffective. Prior radiation therapy and multiple cervical operations militated against attempted direct fistula ligation. Both patients underwent thoracoscopic thoracic duct interruption.ResultsIn both cases, a duct candidate was identified between the aorta and azygos vein. Frozen section analysis of tissue resected between endoclips verified it as thoracic duct. Fistula resolution ensued promptly in both instances.ConclusionsThis report lends further credence to the efficacy of minimally invasive thoracic duct ligation in treating postoperative cervical chylous fistulas. Frozen section confirmation of thoracic duct tissue is useful. It allows one facile with thoracoscopy, but less familiar with thoracic duct ligation, to confidently terminate the operation
The scaling limit of the incipient infinite cluster in high-dimensional percolation. II. Integrated super-Brownian excursion
For independent nearest-neighbour bond percolation on Z^d with d >> 6, we
prove that the incipient infinite cluster's two-point function and three-point
function converge to those of integrated super-Brownian excursion (ISE) in the
scaling limit. The proof is based on an extension of the new expansion for
percolation derived in a previous paper, and involves treating the magnetic
field as a complex variable. A special case of our result for the two-point
function implies that the probability that the cluster of the origin consists
of n sites, at the critical point, is given by a multiple of n^{-3/2}, plus an
error term of order n^{-3/2-\epsilon} with \epsilon >0. This is a strong
statement that the critical exponent delta is given by delta =2.Comment: 56 pages, 3 Postscript figures, in AMS-LaTeX, with graphicx, epic,
and xr package
Phase diagram of aggregation of oppositely charged colloids in salty water
Aggregation of two oppositely charged colloids in salty water is studied. We
focus on the role of Coulomb interaction in strongly asymmetric systems in
which the charge and size of one colloid is much larger than the other one. In
the solution, each large colloid (macroion) attracts certain number of
oppositely charged small colloids (-ion) to form a complex. If the
concentration ratio of the two colloids is such that complexes are not strongly
charged, they condense in a macroscopic aggregate. As a result, the phase
diagram in a plane of concentrations of two colloids consists of an aggregation
domain sandwiched between two domains of stable solutions of complexes. The
aggregation domain has a central part of total aggregation and two wings
corresponding to partial aggregation. A quantitative theory of the phase
diagram in the presence of monovalent salt is developed. It is shown that as
the Debye-H\"{u}ckel screening radius decreases, the aggregation domain
grows, but the relative size of the partial aggregation domains becomes much
smaller. As an important application of the theory, we consider solutions of
long double-helix DNA with strongly charged positive spheres (artificial
chromatin). We also consider implications of our theory for in vitro
experiments with the natural chromatin. Finally, the effect of different shapes
of macroions on the phase diagram is discussed.Comment: 10 pages, 9 figures. The text is rewritten, but results are not
change
Carbon Capture with 4 m Piperazine/4 m 2-Methylpiperazine
AbstractAn equimolar diamine blend of 4 m 2-methylpiperazine (2MPZ) with 4 m piperazine (PZ) is shown to be an attractive solvent for CO2 capture. This blend overcomes the difficulties posed by the narrow solid solubility window of pure 8 m PZ while preserving its benefits. The solid solubility window at 20°C broadens from to . As the blend viscosity is nearly double that of pure PZ, normalizing the capacity by viscosity shows a practical capacity comparable to MEA at 0.63mol CO2/kg solvent. The CO2 absorption rate of the blend is lower, with at 40°C, 84% that of PZ. The heats of CO2 absorption of the blend and PZ are equal at ÎHabs=70kJ/mol. While the blend thermal stability is decreased, Tmax = 155 compared to 163°C, oxidative stability is similar. Lastly, their volatilities are nearly equal with amine Henry's constant near 23Pa at 40°C. In short, the equimolar blend of 4 m 2MPZ with 4 m PZ is a competitive solvent for amine scrubbing
Regulation of valve endothelial cell vasculogenic network architectures with ROCK and Rac inhibitors
Objective: The age- and disease-dependent presence of microvessels within heart valves is an understudied characteristic of these tissues. Neovascularization involves endothelial cell (EC) migration and cytoskeletal reorientation, which are heavily regulated by the Rho family of GTPases. Given that valve ECs demonstrate unique mesenchymal transdifferentiation and cytoskeletal mechanoresponsiveness, compared to vascular ECs, this study quantified the effect of inhibiting two members of the Rho family on vasculogenic network formation by valve ECs. Approach and results: A tubule-like structure vasculogenesis assay (assessing lacunarity, junction density, and vessel density) was performed with porcine aortic valve ECs treated with small molecule inhibitors of Rho-associated serine-threonine protein kinase (ROCK), Y-27632, or the Rac1 inhibitor, NSC-23766. Actin coordination, cell number, and cell migration were assessed through immunocytochemistry, MTT assay, and scratch wound healing assay. ROCK inhibition reduced network lacunarity and interrupted proper cellâcell adhesion and actin coordination. Rac1 inhibition increased lacunarity and delayed actin-mediated network formation. ROCK inhibition alone significantly inhibited migration, whereas both ROCK and Rac1 inhibition significantly reduced cell number over time compared to controls. Compared to a vascular EC line, the valve ECs generated a network with larger total vessel length, but a less smooth appearance. Conclusions: Both ROCK and Rac1 inhibition interfered with key processes in vascular network formation by valve ECs. This is the first report of manipulation of valve EC vasculogenic organization in response to small molecule inhibitors. Further study is warranted to comprehend this facet of valvular cell biology and pathology and how it differs from vascular biology
PetuniaâĂâhybrida floral scent production is negatively affected by highâtemperature growth conditions
Increasing temperatures due to changing global climate are interfering with plantâpollinator mutualism, an interaction facilitated mainly by floral colour and scent. Gas chromatographyâmass spectroscopy analyses revealed that increasing ambient temperature leads to a decrease in phenylpropanoidâbased floral scent production in two PetuniaâĂâhybrida varieties, P720 and Blue Spark, acclimated at 22/16 or 28/22â°C (day/night). This decrease could be attributed to downâregulation of scentârelated structural gene expression from both phenylpropanoid and shikimate pathways, and upâregulation of a negative regulator of scent production, emission of benzenoids V (EOBV). To test whether the negative effect of increased temperature on scent production can be reduced in flowers with enhanced metabolic flow in the phenylpropanoid pathway, we analysed floral volatile production by transgenic âBlue Sparkâ plants overexpressing CaMV 35Sâdriven Arabidopsis thaliana production of anthocyanin pigments 1 (PAP1) under elevated versus standard temperature conditions. Flowers of 35S:PAP1 transgenic plants produced the same or even higher levels of volatiles when exposed to a longâterm highâtemperature regime. This phenotype was also evident when analysing relevant gene expression as inferred from sequencing the transcriptome of 35S:PAP1 transgenic flowers under the two temperature regimes. Thus, upâregulation of transcription might negate the adverse effects of temperature on scent production.We demonstrate that petunia flowers produce less volatile phenylpropanoid compounds, in both scent bouquets and internal pools, in response to elevated temperatures. We reveal that the decrease in floral scent is correlated with reduced transcript levels of scentârelated genes, and that the adverse effect of high temperature can be negated by expressing transcriptional upâregulators. We believe that the conclusions and implications drawn from the original data presented in our manuscript will be of particular interest to a broad spectrum of your readers, particularly in view of recent changes in global climate and the risk of environmental disruption of plantâpollinator mutualism.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112003/1/pce12486-sup-0001-si.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/112003/2/pce12486.pd
Vortices and 2D bosons: A Path-Integral Monte Carlo Study
The vortex system in a high-T_c superconductor has been studied numerically
using the mapping to 2D bosons and the path-integral Monte Carlo method. We
find a single first-order transition from an Abrikosov lattice to an entangled
vortex liquid. The transition is characterized by an entropy jump dS = 0.4 k_B
per vortex and layer (parameters for YBCO) and a Lindemann number c_L = 0.25.
The increase in density at melting is given by d\rho = 6.0*10^{-4} /
\lambda(T)^2. The vortex liquid corresponds to a bosonic superfluid, with
\rho_s = \rho even in the limit \lambda -> \infty.Comment: 9 pages, RevTeX, 4 PostScript figures. The entropy jump at the
transition has been recomputed and is now in agreement with experiments on
YBCO. Some minor modifications were made in the tex
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