No abstract

Older models of intragastric balloons (IGBs) had unacceptably high complication rates and inconsequential weight loss. With FDA approval of newer models, we aimed to systematically examine the literature regarding the efficacy of IGB therapy for obesity. A comprehensive electronic database search was completed. Title searching was restricted to the following keywords: bariatric, gastric, gastric bypass, gastric band, sleeve gastrectomy, and intragastric balloon. Twenty-six primary studies (n = 6101) were included. At balloon removal, mean change in weight and BMI were 15.7 ± 5.3 kg and 5.9 ± 1.0 kg/m(2). The most common complications were nausea/vomiting (23.3 %) and abdominal pain (19.9 %). Serious complications were rare: mortality (0.05 %) and gastric perforation (0.1 %). IGBs are associated with marked short-term weight loss with limited serious complications.

In this study, tensile tests of 63Sn/37Pb solder were carried out at various strain rates from 10−5 s−1 to 10−1 s−1 over a wide temperature range from −40°C to 125°C to study the effect of strain rate and testing temperature on the mechanical properties in a systematic manner. Based on these experimental data, a set of empirical formulae was derived by a statistical method to describe the effect of temperature and strain rate in a quantitative manner and explain the variation in the mechanical properties published in other reports. It is concluded that the empirical formulae can be used to characterize the mechanical properties of 63Sn/37Pb over a wide range of temperatures and strain rates.

No abstract

In this study, a large number of creep tests were carried out to study the effect of stress level and testing temperature on the creep behavior of 63 Sn/37Pb solder in a systematic manner. Based on the dislocation controlled creep mechanism and Gibbs’ free-energy theory, a new creep constitutive model was proposed. The model was found to describe accurately the creep flow of the solder and to be capable of explaining the issues of stress and temperature dependent stress exponent and activation energy in the Arrhenius power-law creep model. Furthermore, the model was employed to predict accurately the long-term reliability of solder joints in a PBGA assembly.