189 research outputs found
Flow-History-Dependent Behavior in Entangled Polymer Melt Flow with Multiscale Simulation
Polymer melts represent the flow-history-dependent behavior. To clearly show
this behavior, we have investigated flow behavior of an entangled polymer melt
around two cylinders placed in tandem along the flow direction in a two
dimensional periodic system. In this system, the polymer states around a
cylinder in downstream side are different from the ones around another cylinder
in upstream side because the former ones have a memory of a strain experienced
when passing around the cylinder in upstream side but the latter ones do not
have the memory. Therefore, the shear stress distributions around two cylinders
are found to be different from each other. Moreover, we have found that the
averaged flow velocity decreases accordingly with increasing the distance
between two cylinders while the applied external force is constant. While this
behavior is consistent with that of the Newtonian fluid, the
flow-history-dependent behavior enhances the reduction of the flow resistance.Comment: 6 pages, 3 figures, Proceedings of 5th International Mini-Symposium
on Liquid
Multiscale Simulation of History Dependent Flow in Polymer Melt
We have developed a new multiscale simulation technique to investigate
history-dependent flow behavior of entangled polymer melt, using a smoothed
particle hydrodynamics simulation with microscopic simulators that account for
the dynamics of entangled polymers acting on each fluid element. The multiscale
simulation technique is applied to entangled polymer melt flow around a
circular obstacle in a two-dimensional periodic system. It is found that the
strain-rate history-dependent stress of the entangled polymer melt affects its
flow behavior, and the memory in the stress causes nonlinear behavior even in
the regions where . The spatial distribution of the
entanglements is also investigated. The slightly low entanglement region
is observed around the obstacle and is found to be broaden in the downstream
region.Comment: 4 pages, 3 figure
Comparison of two different methods of fiber-optic nasal intubation: conventional method versus facilitated method (NASAL-18)
Enzymatic removal of cellulose from cotton/polyester fabric blends
The production of light-weight polyester fabrics from a polyester/cotton blended fabric, by means of the enzymatic removal of the cellulosic part of the material, was investigated. The removal of cotton from the
blended fabric yielded more than 80% of insoluble microfibrillar material by the combined action of high beating effects and cellulase hydrolysis.Other major features of this enzymatic process for converting cotton fibers into microfibrillar material are bath ratio, enzyme dosage and treatment time
Hard X-ray Detector (HXD) on Board Suzaku
The Hard X-ray Detector (HXD) on board Suzaku covers a wide energy range from
10 keV to 600 keV by combination of silicon PIN diodes and GSO scintillators.
The HXD is designed to achieve an extremely low in-orbit back ground based on a
combination of new techniques, including the concept of well-type active shield
counter. With an effective area of 142 cm^2 at 20 keV and 273 cm2 at 150 keV,
the background level at the sea level reached ~1x10^{-5} cts s^{-1} cm^{-2}
keV^{-1} at 30 keV for the PI N diodes, and ~2x10^{-5} cts s^{-1} cm^{-2}
keV^{-1} at 100 keV, and ~7x10^{-6} cts s^{-1} cm^{-2} keV^{-1} at 200 keV for
the phoswich counter. Tight active shielding of the HXD results in a large
array of guard counters surrounding the main detector parts. These
anti-coincidence counters, made of ~4 cm thick BGO crystals, have a large
effective area for sub-MeV to MeV gamma-rays. They work as an excellent
gamma-ray burst monitor with limited angular resolution (~5 degree). The
on-board signal-processing system and the data transmitted to the ground are
also described.Comment: 35 pages, 25 figures and 4 tables; acceted for Publication of the
Astronomical Society of Japa
Synergy between EngE, XynA and ManA from Clostridium cellulovorans on corn stalk, grass and pineapple pulp substrates
The synergistic interaction between various hemi/cellulolytic enzymes has become more important in order to achieve effective and optimal degradation of complex lignocellulose substrates for biofuel production. This study investigated the synergistic effect of three enzymes endoglucanase (EngE), mannanase (ManA) and xylanase (XynA) on the degradation of corn stalk, grass, and pineapple fruit pulp and determined the optimal degree of synergy between combinations of these enzymes. It was established that EngE was essential for degradation of all of the substrates, while the hemicellulases were able to contribute in a synergistic fashion to increase the activity on these substrates. Maximum specific activity and degree of synergy on the corn stalk and grass was found with EngE:XynA in a ratio of 75:25%, with a specific activity of 41.1Β U/mg protein and a degree of synergy of 6.3 for corn stalk, and 44.1Β U/mg protein and 3.4 for grass, respectively. The pineapple fruit pulp was optimally digested using a ManA:EngE combination in a 50:50% ratio; the specific activity and degree of synergy achieved were 52.4Β U/mg protein and 2.7, respectively. This study highlights the importance of hemicellulases for the synergistic degradation of complex lignocellulose. The inclusion of a mannanase in an enzyme consortium for biomass degradation should be examined further as this study suggests that it may play an important, although mostly overlooked, role in the synergistic saccharification of lignocellulose
Lrp4 Modulates Extracellular Integration of Cell Signaling Pathways in Development
The extent to which cell signaling is integrated outside the cell is not currently appreciated. We show that a member of the low-density receptor-related protein family, Lrp4 modulates and integrates Bmp and canonical Wnt signalling during tooth morphogenesis by binding the secreted Bmp antagonist protein Wise. Mouse mutants of Lrp4 and Wise exhibit identical tooth phenotypes that include supernumerary incisors and molars, and fused molars. We propose that the Lrp4/Wise interaction acts as an extracellular integrator of epithelial-mesenchymal cell signaling. Wise, secreted from mesenchyme cells binds to BMP's and also to Lrp4 that is expressed on epithelial cells. This binding then results in the modulation of Wnt activity in the epithelial cells. Thus in this context Wise acts as an extracellular signaling molecule linking two signaling pathways. We further show that a downstream mediator of this integration is the Shh signaling pathway
Predictors of dying at home for patients receiving nursing services in Japan: A retrospective study comparing cancer and non-cancer deaths
<p>Abstract</p> <p>Background</p> <p>The combined effects of the patient's and the family's preferences for death at home have in determining the actual site of death has not been fully investigated. We explored this issue on patients who had been receiving end-of-life care from Visiting Nurse Stations (VNS). In Japan, it has been the government's policy to promote end-of-life care at home by expanding the use of VNS services.</p> <p>Methods</p> <p>A retrospective national survey of a random sample of 2,000 out of the 5,224 VNS was made in January 2005. Questionnaires were mailed to VNS asking the respondents to fill in the questionnaire for each patient who had died either at home or at the hospital from July to December of 2004. Logistic regression analysis was respectively carried out to examine the factors related to dying at home for cancer and non-cancer patients.</p> <p>Results</p> <p>We obtained valid responses from 1,016 VNS (50.8%). The total number of patients who had died in the selected period was 4,175 (cancer: 1,664; non-cancer: 2,511). Compared to cancer patients, non-cancer patients were older and had more impairment in activities of daily living (ADL) and cognitive performance, and a longer duration of care. The factor having the greatest impact for dying at home was that of both the patient and the family expressing such preferences [cancer: OR (95% CI) = 57.00 (38.79-83.76); non-cancer: OR (95% CI) = 12.33 (9.51-15.99)]. The Odds ratio was greater compared with cases in which only the family had expressed such a preference and in which only the patient had expressed such a preference. ADL or cognitive impairment and the fact that their physician was based at a clinic, and not at a hospital, had modest effects on dying at home.</p> <p>Conclusions</p> <p>Dying at home was more likely when both the patient and the family had expressed such preferences, than when the patient alone or the family alone had done so, in both cancer and non-cancer patients. Health care professionals should try to elicit the patient's and family's preferences on where they would wish to die, following which they should then take appropriate measures to achieve this outcome.</p
Genetic Variation in OAS1 Is a Risk Factor for Initial Infection with West Nile Virus in Man
West Nile virus (WNV) is a re-emerging pathogen that can cause fatal encephalitis. In mice, susceptibility to WNV has been reported to result from a single point mutation in oas1b, which encodes 2β²β5β² oligoadenylate synthetase 1b, a member of the type I interferon-regulated OAS gene family involved in viral RNA degradation. In man, the human ortholog of oas1b appears to be OAS1. The βAβ allele at SNP rs10774671 of OAS1 has previously been shown to alter splicing of OAS1 and to be associated with reduced OAS activity in PBMCs. Here we show that the frequency of this hypofunctional allele is increased in both symptomatic and asymptomatic WNV seroconverters (Caucasians from five US centers; total nβ=β501; ORβ=β1.6 [95% CI 1.2β2.0], Pβ=β0.0002 in a recessive genetic model). We then directly tested the effect of this SNP on viral replication in a novel ex vivo model of WNV infection in primary human lymphoid tissue. Virus accumulation varied markedly among donors, and was highest for individuals homozygous for the βAβ allele (P<0.0001). Together, these data identify OAS1 SNP rs10774671 as a host genetic risk factor for initial infection with WNV in humans
- β¦