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Query: UNIPROT:Q86TM3 (cage)
 29,987 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study aims at showing if and to what extent injury severity in frontal car crashes increases with the age of front seat occupants. Data on 2658 belted drivers and front seat passengers in Volvo private car series 140, 240 and 740/760, involved in frontal crashes were extracted from the Volvo Car Crash Register. The results show that the risk of injury resulting in "medical observation" does not increase systematically with age. However, the risk of fracture with any localization is more than three times higher among those aged 65-74 than in those aged 18-24, and the risk of fracture in the rib cage is nearly eleven times higher among the older than in the younger age group. It can be concluded that the incidence of specific types of injuries - as exemplified with fractures of any localization and fractures in the rib cage - increases with advancing age.
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PMID:Age and injury severity. 260 21

Using Car-Parrinello molecular dynamics a structural diffusion mechanism for the simplest hydrophobic species in water, an H atom, is proposed. The hydrophobic solvation cavity is a highly dynamical aggregate that actually drives, by its own hydrogen-bond fluctuations, the diffusion of the enclosed solute. This makes possible an anomalously fast diffusion that falls only short of that of "Grotthuss structural diffusion" of H+ in water. Here, the picture of a static, i.e., "iceberglike," clathrate cage is a misleading concept. The uncovered scenario is similar to the "dynamical hole mechanism" found in a very different context, that is, large molecules moving in hot polymeric melts.
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PMID:Fast anomalous diffusion of small hydrophobic species in water. 1244 32

Car-Parrinello molecular dynamics simulations have been performed on Li(+) and Cl(-) in fully deuterated liquid methanol. The results have been compared with available experimental and theoretical data. It has been found that the lithium cation has a stable tetrahedral coordination, whereas the chloride anion presents an average coordination number of 3.56. The polarization effects induced by the ion on the solvent have been analyzed in terms of Wannier function centers. Particular attention has been devoted to the charge transfer, which is particularly important in these types of systems. Evidence for the stability of the lithium cation solvent cage also has been found in the vibrational spectra.
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PMID:Solvation dynamics of Li+ and Cl- ions in liquid methanol. 1685 58

A Car-Parrinello molecular dynamics simulation has been performed on a solution of Br- in liquid methanol analyzing with particular attention charge transfer and polarization effects. The first solvation shell has been characterized in terms of H-bonds, and it has been found that the high polarization of the bromide gives rise to a stable solvent cage. The differences in the coordination number with the chloride can be ascribed to the ionic radius and to the stronger perturbations brought by the solvent to the bromide ion.
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PMID:Structure and dynamics of Br- ion in liquid methanol. 1686 5

Little is known about the response of the shoulder complex due to lateral and oblique loading. Increasing this knowledge of shoulder response due to these types of loading could aid in improving the biofidelity of the shoulder mechanisms of anthropomorphic test devices (ATDs). The first objective of this study was to define force versus deflection corridors for the shoulder corresponding to both lateral and oblique loading. A second focus of the shoulder research was to study the differences in potential injury between oblique and lateral loading. These objectives were carried out by combining previously published lateral impact data from 24 tests along with 14 additional recently completed lateral and oblique tests. The newly completed tests utilized a pneumatic ram to impact the shoulder of approximately fiftieth percentile sized cadavers at the level of the glenohumeral joint with a constant speed of approximately 4.4 m/sec. Of the 14 tests, four of them were conducted lateral to the shoulder along the subject's y-axis, four of them were conducted 15 anterior to this axis, and six were conducted 30 anterior to the subject's y-axis. As in the previous testing, the first thoracic vertebrae and both shoulders of the subject were instrumented with tri-axial linear accelerometers on the sternum, clavicle, acromion process, and inferior angle of the scapula. The impacting mass was instrumented with an accelerometer and displacement transducer. In addition to this instrumentation, the tests were documented by high-speed digital imagery. Radiographs (x-rays), magnetic resonance images (MRIs), and autopsies were used to document injury to the subjects. The results from the tests revealed differences between the stiffness of the shoulder when loaded laterally to that when it is loaded obliquely. The shoulder was found to deflect twice as much medially when loaded obliquely then when it is loaded laterally. This can be attributed to the ability of the scapula to slide posteriorly around the thoracic cage. The ability of the shoulder to displace medially while simultaneously deflecting posteriorly in oblique impact is important to replicate in the ATDs because it results in the load being transmitted to the upper thoracic cage.
Stapp Car Crash J 2003 Oct
PMID:Shoulder impact response and injury due to lateral and oblique loading. 1709 43

This paper presents the results of dynamic material tests and computational modeling that elucidate the effects of regional rib mechanical properties on thoracic fracture patterns. First, a total of 80 experiments were performed using small cortical bone samples from 23 separate locations on the rib cages of four cadavers (2 male, 2 female). Each specimen was subjected to dynamic three-point bending resulting in an average strain rate of 5 +/- 1.5 strain/s. Test coupon modeling was used to verify the test setup. Regional variation was defined by location as anterior, lateral, or posterior as well as by rib level 1 through 12. The specimen stiffness and ultimate stress and strain were analyzed by location and rib level. Second, these material properties were incorporated into a human body computational model. The rib cage was partitioned into anterior, lateral, and posterior segments and the material properties were varied by location using an elastic-plastic material model. A total of 12 simulations with a rigid impactor were performed including 2 separate material assumptions, original and modified rib properties for regional variations, 3 separate impactor velocities, and 2 directions, anterior and lateral. The data from the material tests for all subjects indicate a statistically significant increase in the average stiffness and average ultimate stress for the cortical bone specimens located in the lateral (11.9 GPa modulus, 153.5 MPa ultimate stress) portion of the ribs versus the anterior (7.51 GPa, 116.7 MPa) and posterior (10.7 GPa, 127.7 MPa) rib locations. In addition, the stiffness, ultimate stress, and ultimate strain for all subjects are significantly different by rib level with each variable generally increasing with increasing rib number. The results from the computational modeling for both frontal and lateral impacts illustrate that the location and number of rib fractures are altered by the inclusion of rib material properties that vary by region.
Stapp Car Crash J 2003
PMID:Defining regional variation in the material properties of human rib cortical bone and its effect on fracture prediction. 1709 52

The purpose of this study was to develop material properties of human rib cortical bone using dynamic tension coupon testing. This study presents 117 human rib cortical bone coupon tests from six cadavers, three male and three female, ranging in age from 18 to 67 years old. The rib sections were taken from the anterior, lateral, and posterior regions on ribs 1 through 12 of each cadaver's rib cage. The cortical bone was isolated from each rib section with a low speed diamond saw, and milled into dog bone shaped tension coupons using a small computer numerical control machine. A high-rate servo-hydraulic Material Testing System equipped with a custom slack adaptor, to provide constant strain rates, was used to apply tension loads to failure at an average rate of 0.5 strains/sec. The elastic modulus, yield stress, yield strain, ultimate stress, ultimate strain, and strain energy density were determined from the resulting stress versus strain curves. The overall average of all cadaver data gives an elastic modulus of 13.9 GPa, a yield stress of 93.9 MPa, a yield strain of 0.88 %, an ultimate stress of 124.2 MPa, an ultimate strain of 2.7 %, and a strain energy density of 250.1 MPa-microstrain. For all cadavers, the plastic region of the stress versus strain curves was substantial and contributed approximately 60 % to the strain energy and over 80 % in the tests with the 18 year old cadaver. The rib cortical bone becomes more brittle with increasing age, shown by an increase in the modulus (p < 0.01) and a decrease in peak strain (p < 0.01). In contrast to previous three-bending tests on whole rib and rib cortical bone coupons, there were no significant differences in material properties with respect to rib region or rib level. When these results are considered in conjunction with the previous three-point bending tests, there is regional variation in the structural response of the human rib cage, but this variation appears to be primarily a result of changes in the local geometry of each rib while the material properties remain nearly constant within an individual.
Stapp Car Crash J 2005 Nov
PMID:Material properties of human rib cortical bone from dynamic tension coupon testing. 1709 75

The human body undergoes a variety of changes as it ages through adulthood. These include both morphological (structural) changes (e.g., increased thoracic kyphosis) and material changes (e.g., osteoporosis). The purpose of this study is to evaluate structural changes that occur in the aging bony thorax and to assess the importance of these changes relative to the well-established material changes. The study involved two primary components. First, full-thorax computed tomography (CT) scans of 161 patients, age 18 to 89 years, were analyzed to quantify the angle of the ribs in the sagittal plane. A significant association between the angle of the ribs and age was identified, with the ribs becoming more perpendicular to the spine as age increased (0.08 degrees/year, p=0.012). Next, a finite element model of the thorax was used to evaluate the importance of this rib angle change relative to other factors associated with aging. A three-factor, two-level factorial design was used to assess the relative importance of rib cage morphology ("young" and "old" rib angle), thickness of the cortical shell (thick = "young" and thin = "old"), and the bone material properties ("young" and "old") on the force-deflection response and injury tolerance of the thorax. The simulations showed that the structural and material changes played approximately equal roles in modulating the force-deflection response of the thorax. Changing the rib angle to be more perpendicular to the spine increased the effective thoracic stiffness, while the "old" material properties and the thin cortical shell decreased the effective stiffness. The offsetting effects of these traits resulted in similar effective thoracic stiffness for the "elderly" and baseline thoracic models, which is consistent with cadaver data available in the literature. All three effects tended to decrease chest deflection tolerance for rib fractures, though the material changes dominated (a four- to six-fold increase in elements eliminated using a maximum strain criterion). The primary conclusion, therefore, is that an older person's thorax, relative to a younger, does not necessarily deform more in response to an applied force. The tolerable sternal deflection level is, however, much less.
Stapp Car Crash J 2005 Nov
PMID:Structural and material changes in the aging thorax and their role in crash protection for older occupants. 1709 76

The effect of pressure on supercritical carbon dioxide (scCO2) has been characterized by using Car-Parrinello molecular dynamics simulations. Structural and dynamical properties along an isotherm of 318.15 K and at pressures ranging from 190 to 5000 bar have been obtained. Intermolecular pair correlation functions and three-dimensional atomic probability density map calculations indicate that the local environment of a central CO2 molecule becomes more structured with increasing pressure. The closest neighbors are predominantly oriented in a distorted T-shaped geometry while neighbors separated by larger distances are likely oriented in a slipped parallel arrangement. The structure of scCO2 at high densities has been compared with that of crystalline CO2. The probability distributions of intramolecular distances narrow down with increasing pressure. A marginal but non-negligible effect of pressure on the instantaneous intramolecular OCO angle is observed, lending credence to the idea that intermolecular interactions between CO2 molecules in an inhomogeneous near neighbor environment could contribute to the observed instantaneous molecular dipole moment. The extent of deviation from a perfect linear geometry of the carbon dioxide molecule decreases with increasing pressure. Time constants derived from reorientational time correlation functions of the molecular backbone compare well with experimental data. Within the range of thermodynamic conditions explored here, no significant changes are observed in the frequencies of intramolecular vibrational modes. However, a blue shift is observed in the low-frequency cage rattling mode with increasing pressure.
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PMID:Evolution of intermolecular structure and dynamics in supercritical carbon dioxide with pressure: an ab initio molecular dynamics study. 1721 90

Aortic injuries during blunt thoracic impacts can lead to life threatening hemorrhagic shock and potential exsanguination. Experimental approaches designed to study the mechanism of aortic rupture such as the testing of cadavers is not only expensive and time consuming, but has also been relatively unsuccessful. The objective of this study was to develop a computer model and to use it to predict modes of loading that are most likely to produce aortic ruptures. Previously, a 3D finite element model of the human thorax was developed and validated against data obtained from lateral pendulum tests. The model included a detailed description of the heart, lungs, rib cage, sternum, spine, diaphragm, major blood vessels and intercostal muscles. However, the aorta was modeled as a hollow tube using shell elements with no fluid within, and its material properties were assumed to be linear and isotropic. In this study fluid elements representing blood have been incorporated into the model in order to simulate pressure changes inside the aorta due to impact. The current model was globally validated against experimental data published in the literature for both frontal and lateral pendulum impact tests. Simulations of the validated model for thoracic impacts from a number of directions indicate that the ligamentum arteriosum, subclavian artery, parietal pleura and pressure changes within the aorta are factors that could influence aortic rupture. The model suggests that a right-sided impact to the chest is potentially more hazardous with respect to aortic rupture than any other impact direction simulated in this study. The aortic isthmus was the most likely site of aortic rupture regardless of impact direction. The reader is cautioned that this model could only be validated on a global scale. Validation of the kinematics and dynamics of the aorta at the local level could not be done due to a lack of experimental data. It is hoped that this model will be used to design experiments that can reproduce field relevant aortic ruptures in the laboratory. Only after such experiments have been run, can local validation be examined and the model judged to be acceptable or unacceptable.
Stapp Car Crash J 2001 Nov
PMID:Development of a computer model to predict aortic rupture due to impact loading. 1745 44


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