Development of a finite element neck model for head-first compressive impacts: Toward the assessment of motorcycle neck protective equipment.

Head-first compressive impacts occur in motorcycle crashes and may result in serious to fatal neck injuries to riders. Equipment to protect the riders' necks from these injuries are available in the market; however, their effectiveness in reducing injury risk is not clear, either due to the lack of scientific evidences or assessment with any prevalently accepted standard. This paper presents a finite element ligamentous neck model, developed as a computationally efficient tool, for future use in the computational phase of assessment process of neck protective equipment. The 3D cervical spine was generated using the mean statistical dimensions of vertebrae and proposed constitutive models, provided in the scientific literature. Ligaments, for the vertebra-vertebra and Hybrid III head-vertebra ligamentous joints, were introduced with the aid of published anatomical descriptions. For validation, the response of the head-neck system under compressive loadings and the flexion-extension bending stiffness of the neck at the segment level were compared against experimental data. The advanced CORrelation and Analysis (CORA) algorithm was applied on the validation responses to assess biofidelity of the model. The results indicate that the model is functional and meets ISO/TR9790 standard as a "good" biofidelic model.

Podophyllotoxin and 6-methoxy podophyllotoxin Production in Hairy Root Cultures of Liunm mucronatum ssp. mucronatum.

AIM: Two bacterial strains of Agrobacterium rhizogenes, A13 and 9534 were evaluated for induction of transformed hairy roots in Linum mucronatum ssp. mucronatum, a high value medicinal plant. MATERIALS AND METHODS: The hairy roots were successfully initiated, through infecting the hypocotyl and root explants and the A13 strain performed a high transformation frequency for hairy roots induction. Transgenic status of hairy roots was confirmed by polymerase chain reaction (PCR) analysis of the rol genes. Growth kinetics of transgenic roots induced by two strains indicated a similar pattern of growth, with maximum growth occurring between 42 to 56 days. The lignan contents in hairy roots were analyzed using high-performance liquid chromatography (HPLC) method. RESULTS: Transformed cultures showed significant differences (P < 0.05) in lignan content. The highest amount of Podophyllotoxin (PTOX, 5.78 mg/g DW) and 6-methoxy podophyllotoxin (MPTOX, 49.19 mg/g DW) was found in transformed lines induced by strain A13, which was four times higher than those of non-transformed roots. The results showed that hairy root cultures of L. mucronatum are rich sources of MPTOX. CONCLUSION: hairy root cultures from L. mucronatum can be used as a useful system for scale-up producing MPTOX and precursors for the production of antitumor agents in substitution with PTOX by considering the appropriate optimizations in future studies.

Closed Extension-Block Pinning for Management of Mallet Fracture - A Case Report Based Description.

INTRODUCTION: Close reduction by extension-block K-wire fixation for acute mallet fracture is based on two sound orthopedic principles - stable arc splinting and early protected motion. Distal interphalangeal joint splinting is still the technique commonly used for mallet fractures with significant morbidity and only moderate functional outcome. CASE REPORT: We have demonstrated here Ishiguro's technique in a partially treated 2 weeks old mallet fracture with the flexion deformity at distal interphalangeal (DIP) joint after proper preoperative assessment. Peroperatively, proper anatomical localization of mallet fragment was done under fluoroscopy. Reduction of the avulsion fracture was done by extension block K-wire and intra-articular K-wire was inserted subsequently to hold the reduction in place and DIP joint in extension. Later on K-wires were removed at the end of 6 weeks follow up. Patient was subjected to the physiotherapy during the course of the treatment. Excellent functional outcome was noted at the end of three months. CONCLUSION: Closed Extension block pinning can give acceptable functional outcome even in delayed mallet finger injuries. Full range of movement at the affected joint is an important pre-requisite for the same.