1,577 research outputs found
Medium effects on the selection of sequences folding into stable proteins in a simple model
We study the medium effects on the selection of sequences in protein folding
by taking account of the surface potential in HP-model. Our analysis on the
proportion of H and P monomers in the sequences gives a direct interpretation
that the lowly designable structures possess small average gap. The numerical
calculation by means of our model exhibits that the surface potential enhances
the average gap of highly designable structures. It also shows that a most
stable structure may be no longer the most stable one if the medium parameters
changed.Comment: 4 pages, 4 figure
Polyols Prepared from Ring-Opening Epoxidized Soybean Oil by a Castor Oil-Based Fatty Diol
Several biorenewable vegetable oil-based polyols with different molecular weights and various hydroxyl functionalities were successfully prepared by ring-opening epoxidized soybean oil with a castor oil-based fatty diol. It was found that several factors, including reaction time, reaction temperature, and molar ratios between epoxidized soybean oil and castor oil diol, affect structures and rheology behaviors of the final polyols. Proton NMR, FT-IR, GPC, and rheometry results revealed that the hydroxyl functionalities, molecular weight, and viscosity of the polyols could be tailored by controlling the above-mentioned factors. Besides, the role of solvents in the epoxy ring-opening process was investigated as well
The relation of H2CO, 12CO, and 13CO in molecular clouds
Aims. We seek to understand how the 4.8 GHz formaldehyde absorption line is
distributed in the MON R2, S156, DR17/L906, and M17/M18 regions. More
specifically, we look for the relationship among the H2CO, 12CO, and 13CO
spectral lines. Methods. The four regions of MON R2 (60'x90'), S156 (5'0x70'),
DR17/L906 (40'x60'), and M17 /M18 (70'x80')were observed for H2CO (beam 10'),
H110a recombination (beam 10'), 6 cm continuum (beam 10'), 12CO (beam 1'), and
13CO (beam 1'). We compared the H2CO,12CO,13CO, and continuum distributions,
and also the spectra line parameters of H2CO,12CO, and 13CO. Column densities
of H2CO,13CO, and H2 were also estimated. Results. We found out that the H2CO
distribution is similar to the 12CO and the 13CO distributions on a large
scale. The correlation between the 13 CO and the H2CO distributions is better
than between the 12CO and H2CO distributions. The H2CO and the 13CO tracers
systematically provide consistent views of the dense regions. T heir maps have
similar shapes, sizes, peak positions, and molecular spectra and present
similar centr al velocities and line widths. Such good agreement indicates that
the H2CO and the 13CO arise from similar regions.Comment: 21 pages, 12 figures published, 201
Cerebral hemodynamic characteristics of acute mountain sickness upon acute high-altitude exposure at 3,700 m in young Chinese men.
PURPOSE: We aimed at identifying the cerebral hemodynamic characteristics of acute mountain sickness (AMS). METHODS: Transcranial Doppler (TCD) sonography examinations were performed between 18 and 24 h after arrival at 3,700 m via plane from 500 m (n = 454). A subgroup of 151 subjects received TCD examinations at both altitudes. RESULTS: The velocities of the middle cerebral artery, vertebral artery (VA) and basilar artery (BA) increased while the pulsatility indexes (PIs) and resistance indexes (RIs) decreased significantly (all p < 0.05). Velocities of BA were higher in AMS (AMS+) individuals when compared with non-AMS (AMS-) subjects (systolic velocity: 66 ± 12 vs. 69 ± 15 cm/s, diastolic velocity: 29 ± 7 vs. 31 ± 8 cm/s and mean velocity, 42 ± 9 vs. 44 ± 10 cm/s). AMS was characterized by higher diastolic velocity [V d_VA (26 ± 4 vs. 25 ± 4, p = 0.013)] with lower PI and RI (both p = 0.004) in VA. Furthermore, the asymmetry index (AI) of VAs was significantly lower in the AMS + group [-5.7 % (21.0 %) vs. -2.5 % (17.8 %), p = 0.016]. The AMS score was closely correlated with the hemodynamic parameters of BA and the V d_VA, PI, RI and AI of VA. CONCLUSION: AMS is associated with alterations in cerebral hemodynamics in the posterior circulation rather than the anterior one, and is characterized by higher blood velocity with lower resistance. In addition, the asymmetry of VAs may be involved in AMS
Research on Warnings with New Thought of Neuro-IE
AbstractSafety production is a seriously stubborn problem in modern industry engineering. Warnings, as the most fundamental and important measure used in safety management, especially in Mine Exploitation, have played a vital role in risk cognition, behaviors guide and accidents prevention. However, traditional researches are so subjective that it's hard to deeply explore the inner mechanism and process, which has been hidden behind the outer behaviors. As a result, the effectiveness of Warnings is much discounted. In this paper, we make use of neuroscience methods to study Warnings from the basically cognitive levels and have acquired preliminary achievements, which provide new evidence, discussion and introductions for former researches
Age as a risk factor for acute mountain sickness upon rapid ascent to 3,700 m among young adult Chinese men.
BackgroundThe aim of this study was to explore the relationship between age and acute mountain sickness (AMS) when subjects are exposed suddenly to high altitude.MethodsA total of 856 young adult men were recruited. Before and after acute altitude exposure, the Athens Insomnia Scale score (AISS) was used to evaluate the subjective sleep quality of subjects. AMS was assessed using the Lake Louise scoring system. Heart rate (HR) and arterial oxygen saturation (SaO2) were measured.ResultsResults showed that, at 500 m, AISS and insomnia prevalence were higher in older individuals. After acute exposure to altitude, the HR, AISS, and insomnia prevalence increased sharply, and the increase in older individuals was more marked. The opposite trend was observed for SaO2. At 3,700 m, the prevalence of AMS increased with age, as did severe AMS, and AMS symptoms (except gastrointestinal symptoms). Multivariate logistic regression analysis showed that age was a risk factor for AMS (adjusted odds ratio [OR] 1.07, 95% confidence interval [CI] 1.01-1.13, P<0.05), as well as AISS (adjusted OR 1.39, 95% CI 1.28-1.51, P<0.001).ConclusionThe present study is the first to demonstrate that older age is an independent risk factor for AMS upon rapid ascent to high altitude among young adult Chinese men, and pre-existing poor subjective sleep quality may be a contributor to increased AMS prevalence in older subjects
METHOD BASED DEA FOR MULTIPLE ATTRIBUTE DECISION MAKING
Using DEA, A new concept for multiple attribute decision making and analysis, relative efficiency and weak relative efficiency is proposed with its relations to the Pareto efficiency being discussed, its economic interpretation and geometrical meaning and existence theorem being given. On the basis of this concept, a new method of unified evaluations and decision making and analysis is designed. Finally, some useful suggestion are given for the applications in R&D project selection and science & technology achievement evaluations. Key words: DEA, multiple attribute decision making, project selection and evaluatio
DiaquaÂbisÂ(1-methyl-1H-imidazole-κN 3)bisÂ[2-(naphthalen-1-yl)acetato-κO]cobalt(II)
In the title compound, [Co(C12H9O2)2(C4H6N2)2(H2O)2], the CoII ion is located on an inversion centre and displays a distorted octaÂhedral coordination geometry. Two O atoms from two water molÂecules and two carboxylÂate O atoms from two 2-(naphthalen-1-yl)acetate ligands are in the equatorial plane and two N atoms from two 1-methyl-1H-imidazole ligands are in the axial positions. The structure is stabilized by intraÂmolecular O—H⋯O hydrogen bonds. InterÂmolecular O—H⋯O hydrogen bonds link the complex molÂecules into chains along [100]
BisÂ(2-methyl-1H-imidazole-κN 3)bis[2-(naphthalen-2-yl)acetato-κO]copper(II)
In the crystal structure of the title compound, [Cu(C12H9O2)2(C4H6N2)2], the Cu(II) cations are square-planar coordinated by two 1-naphthylÂacetate anions and two 2-methyl-imidazole ligands into discrete complexes that are located on centres of inversion. These complexes are linked into chains parallel to [010] by interÂmolecular N—H⋯O hydrogen bonding between the N—H H atom of the 2-methyl-imidazole ligands and the carboxylÂate O atoms that are not involved in metal coordination
- …