1,627 research outputs found
Prevention of neck injury in frontal impacts
'Whiplash' or Soft Tissue Neck Injwy (STNI) has traditionally been
recognized as a car-to-car rear impact phenomenon; studies worldwide verify that the
risk of sustaining neck injury in a car crash is approximately three-fold the risk of
sustaining the same injury in other crash-types. In general, as such injuries are not
characterized by a high risk of threat-to-life (as measured by internationally adopted
injury severity scales such as the Abbreviated Injury Scale), prevention of them has
perhaps not been seen as a high priority. However, in recent times, it has been
recognized that such injury can be very debilitating to those afflicted and costs to
sociery as a result of the injury can be correspondingly high.
Techniques have therefore evolved over the past 5-l0 years that are aimed at the
prevention of neck injury, mostly in rear impacts, and these are predominantly based
on current understandings of the actual injurycoupled with the injury mechanism.
Such studies usually indicate that the design of vehicle seat and head restraint is
critical in the prevention of neck injury.
However, neck injury does not only occur in rear-end crashes. Some studies have
shown that the risk of sustaining neck injury in front and side impacts is between 15-20%. As these crash-types occur more frequently than rear impacts, the actual
exposure to neck injury could be higher than in rear impacts. However, so far there
have been no design techniques specifically aimed at neck injury prevention in such
impacts.
Recently, two studies of real-world crashes have examined the effects of arl-bags in
frontal impacts. These are reported in this paper. Both studies have shown that the
deploying air-bag in conjunction with a seat belt in a frontal crash can significantly
reduce the incidence of neck injury in a frontal impact. The first is an on-going study
of vehicle crash performance and occupant injury which is being conducted by
Folksam Insurance in Sweden using data obtained from on-board crash recorders.
The second study uses preliminary data from an on-going study of vehicle crash
peiformance and occupant injury, which is being conducted by the Monash Universiy's
Accident Research Centre
Statins and muscle pain
Introduction: Statins remain among the most frequently prescribed drugs and constitute a cornerstone in the prevention of cardiovascular disease. However, muscle symptoms are often reported from patients on statins. Muscle symptoms are frequently reported as adverse events associated with statin therapy.Areas covered: In the present narrative review, statin-associated muscle pain is discussed. It elucidates potential mechanisms and possible targets for management.Expert opinion: In general, the evidence in support of muscle pain caused by statins is in some cases equivocal and not particularly strong. Reported symptoms are difficult to quantify. Rarely is it possible to establish a causal link between statins and muscle pain. In randomized controlled trials, statins are well tolerated, and muscle-pain related side-effects is similar to placebo. There are also nocebo effects of statins. Exchange of statin may be beneficial although all statins have been associated with muscle pain. In some patients reduction of dose is worth trying, especially in primary prevention Although the benefits of statins outweigh potential risks in the vast majority of cases, careful clinical judgment may be necessary in certain cases to manage potential side effects on an individual basis
Personality inventory for children: a measure of biopsychosocial status in children and adolescent
Non-Volatile Control of Valley Polarized Emission in 2D WSe2-AlScN Heterostructures
Achieving robust and electrically controlled valley polarization in monolayer
transition metal dichalcogenides (ML-TMDs) is a frontier challenge for
realistic valleytronic applications. Theoretical investigations show that
integration of 2D materials with ferroelectrics is a promising strategy;
however, its experimental demonstration has remained elusive. Here, we
fabricate ferroelectric field-effect transistors using a ML-WSe2 channel and a
AlScN ferroelectric dielectric, and experimentally demonstrate efficient tuning
as well as non-volatile control of valley polarization. We measured a large
array of transistors and obtained a maximum valley polarization of ~27% at 80 K
with stable retention up to 5400 secs. The enhancement in the valley
polarization was ascribed to the efficient exciton-to-trion (X-T) conversion
and its coupling with an out-of-plane electric field, viz. the quantum-confined
Stark effect. This changes the valley depolarization pathway from strong
exchange interactions to slow spin-flip intervalley scattering. Our research
demonstrates a promising approach for achieving non-volatile control over
valley polarization and suggests new design principles for practical
valleytronic devices.Comment: Manuscript (22 pages and 5 figures), supporting informatio
A new species of Stenobiella Tillyard (Neuroptera, Berothidae) from Australia
Stenobiella variola sp. n., a new species of beaded lacewing (Neuroptera: Berothidae), is described and figured from south-eastern Australia. A preliminary key to Stenobiella species is presented
Islet antibodies and remaining beta-cell function 8 years after diagnosis of diabetes in young adults: a prospective follow-up of the nationwide Diabetes Incidence Study in Sweden.
Objectives. To establish the prevalence of remaining beta-cell function 8 years after diagnosis of diabetes in young adults and relate the findings to islet antibodies at diagnosis and 8 years later. Design. Population-based cohort study. Setting. Nationwide from all Departments of Medicine and Endocrinology in Sweden. Subjects. A total of 312 young (15-34 years old) adults diagnosed with diabetes during 1987-88. Main outcome measure. Plasma connecting peptide (C-peptide) 8 years after diagnosis. Preserved beta-cell function was defined as measurable C-peptide levels. Three islet antibodies - cytoplasmic islet cell antibodies (ICA), glutamic acid decarboxylase antibodies and tyrosine phosphatase antibodies - were measured. Results. Amongst 269 islet antibody positives (ab+) at diagnosis, preserved beta-cell function was found in 16% (42/269) 8 years later and these patients had a higher body mass index (median 22.7 and 20.5 kg m-2, respectively; P = 0.0003), an increased frequency of one islet antibody (50 and 24%, respectively; P = 0.001), and a lower prevalence of ICA (55 and 6%, respectively; P = 0.007) at diagnosis compared with ab+ without remaining beta-cell function. Amongst the 241 patients without detectable beta-cell function at follow-up, 14 lacked islet antibodies, both at diagnosis and at follow-up. Conclusions. Sixteen per cent of patients with autoimmune type 1 diabetes had remaining beta-cell function 8 years after diagnosis whereas 5.8% with beta-cell failure lacked islet autoimmunity, both at diagnosis and at follow-up
Tribocorrosion behavior of beta titanium biomedical alloys in phosphate buffer saline solution
[EN] The tribo-electrochemical behavior of different β titanium alloys for biomedical applications sintered by powder metallurgy has been investigated. Different mechanical, electrochemical and optical techniques were used to study the influence of the chemical composition, Sn content, and the electrochemical conditions on the tribocorrosion behavior of those alloys Ti30NbxSn alloys (where x is the weight percentage of Sn content, 2% and 4%).
Sn content increases the active and passive dissolution rate of the titanium alloys, thus increasing the mechanically activated corrosion under tribocorrosion conditions. It also increases the mechanical wear of the alloy. Prevailing electrochemical conditions between 1 and 2 V influences the wear accelerated corrosion by increasing it with the applied potential and slightly increases the mechanical wear of Ti30Nb4Sn.
Wear accelerated corrosion can be predicted by existing models as a function of electrochemical and mechanical parameters of the titanium alloys.The authors would like to thank the Ministerio de Ciencia e Innovacion of the Spanish government for the financial support under the project MAT2011-22481.Guiñón Pina, V.; Dalmau, A.; Devesa, F.; Amigó Borrás, V.; Igual Muñoz, AN. (2015). Tribocorrosion behavior of beta titanium biomedical alloys in phosphate buffer saline solution. Journal of the Mechanical Behavior of Biomedical Materials. 46:59-68. https://doi.org/10.1016/j.jmbbm.2015.02.016S59684
Solution structure of Mannobioses unravelled by means of Raman optical activity
Structural analysis of carbohydrates is a complicated endeavour, due to the complexity and diversity of the samples at hand. Herein, we apply a combined computational and experimental approach, employing molecular dynamics (MD) and density functional theory (DFT) calculations together with NMR and Raman optical activity (ROA) measurements, in the structural study of three mannobiose disaccharides, consisting of two mannoses with varying glycosidic linkages. The disaccharide structures make up the scaffold of high mannose glycans and are therefore important targets for structural analysis. Based on the MD population analysis and NMR, the major conformers of each mannobiose were identified and used as input for DFT analysis. By systematically varying the solvent models used to describe water interacting with the molecules and applying overlap integral analysis to the resulting calculational ROA spectra, we found that a full quantum mechanical/molecular mechanical approach is required for an optimal calculation of the ROA parameters. Subsequent normal mode analysis of the predicted vibrational modes was attempted in order to identify possible marker bands for glycosidic linkages. However, the normal mode vibrations of the mannobioses are completely delocalised, presumably due to conformational flexibility in these compounds, rendering the identification of isolated marker bands unfeasible
Comparison of APACHE II and three abbreviated APACHE II scores for predicting outcome among emergency trauma patients
Molecular dynamics simulations of the Cx26 hemichannel: Evaluation of structural models with Brownian dynamics
The recently published crystal structure of the Cx26 gap junction channel provides a unique opportunity for elucidation of the structure of the conductive connexin pore and the molecular determinants of its ion permeation properties (conductance, current–voltage [I-V] relations, and charge selectivity). However, the crystal structure was incomplete, most notably lacking the coordinates of the N-terminal methionine residue, which resides within the pore, and also lacking two cytosolic domains. To allow computational studies for comparison with the known channel properties, we completed the structure. Grand canonical Monte Carlo Brownian dynamics (GCMC/BD) simulations of the completed and the published Cx26 hemichannel crystal structure indicate that the pore is too narrow to permit significant ion flux. The GCMC/BD simulations predict marked inward current rectification and almost perfect anion selectivity, both inconsistent with known channel properties. The completed structure was refined by all-atom molecular dynamics (MD) simulations (220 ns total) in an explicit solvent and POPC membrane system. These MD simulations produced an equilibrated structure with a larger minimal pore diameter, which decreased the height of the permeation barrier formed by the N terminus. GCMC/BD simulations of the MD-equilibrated structure yielded more appropriate single-channel conductance and less anion/cation selectivity. However, the simulations much more closely matched experimentally determined I-V relations when the charge effects of specific co- and posttranslational modifications of Cx26 previously identified by mass spectrometry were incorporated. We conclude that the average equilibrated structure obtained after MD simulations more closely represents the open Cx26 hemichannel structure than does the crystal structure, and that co- and posttranslational modifications of Cx26 hemichannels are likely to play an important physiological role by defining the conductance and ion selectivity of Cx26 channels. Furthermore, the simulations and data suggest that experimentally observed heterogeneity in Cx26 I-V relations can be accounted for by variation in co- and posttranslational modifications
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