Dentist’s drill allergy?

Subcutaneous emphysema of the face and neck can develop following restorative dentistry, particularly when air turbine drills are used. We present a case in which the dentist mistook the subcutaneous emphysema following such a procedure for an allergic/anaphylactic reaction and sent him to the emergency department in an ambulance. The differential diagnosis and the subsequent management, including the role of oxygen and techniques to prevent such complications, are discussed

Highly active thermally stable beta-nucleating agents for isotactic polypropylene

Calcium salts of suberic (Ca-Sub) and pimelic (Ca Pim) acids were synthesized and implemented as in different grades of isotactic polypropylene (IPP). Propylene homopolymer, as well as random and block copolymers containing these additives, crystallized iPP into pure or nearly pure beta modification in the isothermal and nonisothermal crystallization experiments. Recently, Ca-Sub proved to be the most effective beta-nucleating agent of iPP. The Ca-Sub nucleating agent widens the upper crystallization temperature range of pure beta-iPP formation up to 140 degrees C. In this study the effect of the these additives on the crystallization, melting characteristics, and structure of the PP were studied. The degree of crystallinity of beta-iPP was markedly higher than that of alpha-iPP. A widening in the melting peak of the samples crystallized in a high temperature range was first observed and discussed in regard to literature results of the same phenomenon for alpha-iPP. The morphology of the beta-iPP samples was revealed by scanning electron microscopy. Independent of the type of polymer or nucleating agent, hedritic structures were found in the early stages of growth of the beta-spherulites. (C) 1999 John Wiley & Sons, Inc

Epidural catheter connectors: a laboratory-based comparison of the Portex Tuohy-Borst and EpiFuse™ designs *

Disconnection of an epidural catheter from its connector may result in patient harm and commonly requires resiting of the epidural. Clamp-connector designs such as the novel Portex EpiFuseTM potentially offer an improved safety profile over screw-cap designs such as the Tuohy-Borst, but comparative studies are limited. We therefore compared the tensile strength of EpiFuse and Tuohy-Borst connectors in a laboratory setting.We further sought to establish whether operator modification of the EpiFuse increased its vulnerability to disconnection. The median (IQR [range]) force to induce disconnection was 8.0 (4.1–12.8 [0.0–22.6]) N for Tuohy-Borst connectors and 16.4 (15.2–17.7 [5.7–18.9]) and 15.9 (15.0–16.9 [5.8–18.1]) N for standard and modified EpiFuse connectors, respectively (p < 0.0001). The Tuohy-Borst was also less likely to meet British Standard requirements (13 ⁄ 20 sets vs 19 ⁄ 20 and 20 ⁄ 20, p = 0.002). Modification of the EpiFuse did not affect lumen patency or connection strength