SANS study of the distribution of water within starch granules.

This study describes contrast variation small angle neutron scattering (SANS) experiments which focus on the role which the intra-granular room temperature distribution of water and carbohydrate plays in determining the native structure and subsequent functionality of starch. It is shown that variations in botanical origin and amylose content do not correlate with significant differences in room temperature composition of A-type starch granules. In turn, variations in the gelatinisation behaviour of A-type starches do not correlate with variations in room temperature water distribution. In contrast, the room temperature water content is found to differ significantly between granules of potato (B-type) and a range of A-type starch cultivars. A correlation is found between these compositional differences and variations in crystal structure, which has implications for biological growth conditions and gelatinisation behaviour.

Late mandibular fracture after third molar surgery: a survey of Connecticut oral and maxillofacial surgeons.

PURPOSE: This study investigated the incidence and causative factors involved in late mandibular fractures after third molar surgery. MATERIALS AND METHODS: A questionnaire was sent to 106 oral and maxillofacial surgeons in Connecticut, asking them about their experience with late fractures over a 10-year period. RESULTS: A 79% response indicated 28 fractures occurring in 611,000 extractions, for an incidence of 0.0046%. The cause was found to be multifactorial and included age, gender, type of impaction, preexisting infection, and failure to maintain a soft diet in the postoperative period. Most fractures occurred between the 1st and 21st days postoperatively. Three of the fractures resulted in malpractice litigation. CONCLUSION: Men over the age of 25 years should be specifically informed about the risk of late mandible fracture after third molar surgery. This group of patients should be educated about the quality and duration of a soft diet.

The role of plasticization in starch granule assembly.

There is a growing interest in the nonfood usage of starch-based products. This interest is predominantly motivated by the ability to produce thermoplastic materials, known as thermoplastic starch (TPS), which can be manufactured using technology already developed for the production of synthetic plastics yet which are fully biodegradable. With the strength and flexibility of TPS materials being highly dependent upon the presence of nonaqueous plasticizing solvents, the nature of the interaction between starch and plasticizer is of obvious interest. As well as interest in the industrial applications of starch, the general nature of plasticization and structure formation within native starch granules is of fundamental interest. This paper presents results from a small and wide angle scattering and calorimetric investigation of model starch-plasticizer systems. Issues relevant to TPS production are addressed, and a model of lamellar assembly within starch granules facilitated by the plasticizing effect of low molecular weight solvents is proposed.