Simultaneous Three-Dimensional Analysis of Cervical Spine Kinematics in the Axial and Sagittal Views during a Simulated Frontal Impact: Differences between Tensed and Relaxed States

Study DesignProspective experimental study on humans.PurposeTo determine whether postural differences during a low-speed impact are observed in the sagittal and axial views, particularly in a relaxed state.Overview of Literature: Three-dimensional motion capture systems have been used to analyze posture and head-neck-torso kinematics in humans during a simulated low-speed impact, yet little research has focused on the axial view. Since a seatbelt asymmetrically stabilizes a drivers right shoulder and left lower waist into the seat, it potentially creates movement in the axial view.MethodsThree healthy adult men participated in the experimental series, which used a low-speed sled system. The acceleration pulse created a full sine shape with a maximum acceleration of 8.0 m/s2 at 500 ms, during which the kinematics were evaluated in relaxed and tensed states. The three-dimensional motion capture system used eight markers to record and analyze body movement and head-neck-torso kinematics in the sagittal and axial views during the low-speed impact. Head and trunk rotation angles were also calculated.ResultsLarger movements were observed in the relaxed than in the tensed state in the sagittal view. The cervical and thoracic spine flexed and extended, respectively, in the relaxed state. In the axial view, larger movements were also observed in the relaxed state than in the tensed state, and the left shoulder rotated.ConclusionsDuring simulated frontal impact, the rotation angle between the head and trunk was significantly larger in the relaxed state. Therefore, we recommend also observing movement in the axial view during impact tests

病原性 Candida 酵母から調製した粗抽出物の 1H-NMR 分析によって得られる細胞壁ﾏﾝﾅﾝの構造情報について

病原性 Candida 酵母の乾燥菌体から精製されたﾏﾝﾅﾝのﾌﾟﾛﾄﾝ核磁気共鳴(1H-NMR)分析(測定温度45℃)において､ﾏﾝﾉｰｽ残基に基づくｱﾉﾒﾘｯｸﾌﾟﾛﾄﾝｼｸﾞﾅﾙ領域(4.5～6.0ppm)に観察されるｼｸﾞﾅﾙは極めて明瞭であった｡一方､同一酵母の粗抽出物の 1H-NMR 分析(測定温度70℃)におけるこの領域のｼｸﾞﾅﾙは､僅かに不明瞭な部分が観察されるものの､ほぼ精製ﾏﾝﾅﾝに匹敵するｼｸﾞﾅﾙﾊﾟﾀｰﾝを観察することができた｡従って､酵母細胞壁ﾏﾝﾅﾝの化学構造に関して､ﾏﾝﾅﾝを精製する前段階である粗抽出物の NMR 分析によって､精製ﾏﾝﾅﾝの NMR 分析とほぼ同等の情報が得られることが明らかになった｡In the measurement of 1H-NMR of purified mannan obtained from dried cells of pathogenic Candida yeast, the extremely clear signal is observed anomeric proton region(4.5～6.0ppm)based on mannose residues. On the other hand, in the 1H-NMR analysis of the crude extract obtained from the same yeast, part obscured slightly observed, but the signal pattern equivalent to purified mannan substantially was observed. Therefore, it was demonstrated that 1H-NMR analysis of the crude extract obtained in the previous step of purification of mannan give the rough information for the chemical structure of the yeast cell wall mannan

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Influence of the Driver Conditions on the Injury Outcome in Front Impact Collisions

Changes in the driver's posture and velocity caused by inertia during an emergency braking are believed to affect the injury outcome in front impact collisions. Moreover, at equivalent impact conditions, the results from real-world data analysis show the increased risk of injury in the cases in which an emergency braking preceded the accident. The objective of this study is to further investigate the relationship between such driver's pre-crash conditions and the injury outcome by using a computer human model. A finite element human model (JAMA model) and the results of the pre-impact experiments with volunteers were employed for this purpose. By simulating the same two accidents after different pre-impact conditions it was concluded that the presence of a pre-impact emergency braking increased the severity of the loading mechanism sustained by the driver, especially on the thoracic region

Rat brain kinematics and tissue strains associated to Diffuse Axonal Injuries induced by head rotational acceleration

An anatomically detailed finite element model of a rat head-neck complex has been developed from medical images. The model incorporates material properties from tissue indentation test data captured in the coronal plane from seven brain regions to account for non-homogeneity. The local brain-skull relative displacement has been validated against local brain-slip experimental data in which a thin pin was entered the cortex and rigidly attached to the skull prior to impact. The model is being used to improve the understanding of brain rotational kinematics and to develop brain tissue injury thresholds for Diffuse Axonal Injuries as detected through immuno-histology

Development of a comprehensive injury criterion for moderate and mild traumatic brain injuries

Traumatic brain injuries are commonly caused by blows that produce sudden accelerations of the head. A methodology to define a new global brain injury criterion and thresholds that account for time-dependent and combined translational-rotational kinematics of the head is described in this paper. In total 43 head impact tests with monkeys conducted in the past were reproduced, using a finite element model of the monkey head and neck. The study found that the new criterion predicted concussions and brain tissue strains more precisely than past criteria. A scheme that scales the proposed injury threshold to be applicable for humans is proposed. The new criterion and threshold may then be used in the design of superior protective systems

Reanalysis of Monkey Head Concussion Experiment Data Using a Novel Monkey Finite Element Model to Develop Brain Tissue Injury Reference Values

A new method has been applied to develop a Finite Element (FE) model of the head‐ neck complexof Macaque monkey from medical images. The skull, brain and flesh have been validated based on tissue andcomponent experimental data from literature. The kinematics of the head during occipital impacts have beenvalidated against a sub‐set of head impact experiments carried out in the past at the Japan AutomobileResearch Institute (JARI). The validated model has been used to simulate 19 occipital impacts case‐by‐case. Thecorrelation between obtained peak values for a number of mechanical parameters of the different brain regionsand the occurrence of concussion in the experiments was analysed. Maximum principal strain in the brainstemshowed significant correlation to concussion; 21% strain was associated with a probability of 50% risk forconcussion. The developed model and the presented results constitute the first step towards the developmentof a tissue level injury criterion for humans that is based on experimental animal data

Development of a Comprehensive Injury Criterion for Moderate and Mild Traumatic Brain Injuries

Traumatic brain injuries are commonly caused by blows that produce sudden accelerations of the head. A methodology to define a new global brain injury criterion and thresholds that account for time-dependent and combined translational-rotational kinematics of the head is described in this paper. In total 43 head impact tests with monkeys conducted in the past were reproduced, using a finite element model of the monkey head and neck. The study found that the new criterion predicted concussions and brain tissue strains more precisely than past criteria. A scheme that scales the proposed injury threshold to be applicable for humans is proposed. The new criterion and threshold may then be used in the design of superior protective systems

Development of a comprehensive injury criterion for moderate and mild traumatic brain injuries

Traumatic brain injuries are commonly caused by blows that produce sudden accelerations of the head. A methodology to define a new global brain injury criterion and thresholds that account for time-dependent and combined translational-rotational kinematics of the head is described in this paper. In total 43 head impact tests with monkeys conducted in the past were reproduced, using a finite element model of the monkey head and neck. The study found that the new criterion predicted concussions and brain tissue strains more precisely than past criteria. A scheme that scales the proposed injury threshold to be applicable for humans is proposed. The new criterion and threshold may then be used in the design of superior protective systems