Analysis of testosterone esters by tandem mass spectrometry

OBJECTIVE: To assess the efficacy of external cephalic version, including safety, cost-benefit analysis, and impact on the cesarean delivery rate. DATA SOURCES: A MEDLINE search was conducted to identify all articles published in English between 1980-1991 on external cephalic version. References were also cross-checked for all reports. METHODS OF STUDY SELECTION: We reviewed only those articles providing sufficiently detailed data to determine actual numbers of subjects. In cases of duplicate results, only the latest publication was used. Rates of successful version, cesarean delivery, and fetal and maternal complications were presented. DATA EXTRACTION AND SYNTHESIS: Among the United States trials, the success rate was approximately 65% (range 48-77%), and once version succeeded, almost all the fetuses stayed in the vertex position until birth. Among those in whom external version was performed, the mean cesarean delivery rate was 37%, compared with 83% in controls (P < .001). External version would also save 12.3% of the costs of delivering breech patients overall. CONCLUSION: External cephalic version is safe and cost-effective. It substantially reduces the cesarean delivery rate among breech presentations, decreases the risk related to breech delivery, and avoids cesarean delivery in subsequent pregnancies. However, external version will not have a major impact on the high overall cesarean birth rate.     

Optimization of thermal interface materials for electronics cooling applications

Thermal interface materials (TIMs) are used in electronics cooling applications to decrease the thermal contact resistance between surfaces in contact. A methodology to determine the optimal volume fraction of filler particles in TIMs for minimizing the thermal contact resistance is presented. The method uses finite element analysis to solve the coupled thermo-mechanical problem. It is shown that there exists an optimal filler volume fraction which depends not only on the distribution of the filler particles in a TIM but also on the thickness of the TIM layer, the contact pressure and the shape and the size of the filler particles. A contact resistance alleviation factor is defined to quantify the effect of these parameters on the contact conductance with the use of TIMs. For the filler and matrix materials considered-platelet-shaped boron nitride filler particles in a silicone matrix-the maximum observed enhancement in contact conductance with the use of TIMs was by a factor of as much as nine.     

Uncertainty‐conscious methodology for process performance assessment in biopharmaceutical drug product manufacturing

This work presents an uncertainty‐conscious methodology for the assessment of process performance—for example, run time—in the manufacturing of biopharmaceutical drug products. The methodology is presented as an activity model using the type 0 integrated definition (IDEF0) functional modeling method, which systematically interconnects information, tools, and activities. In executing the methodology, a hybrid stochastic–deterministic model that can reflect operational uncertainty in the assessment result is developed using Monte Carlo simulation. This model is used in a stochastic global sensitivity analysis to identify tasks that had large impacts on process performance under the existing operational uncertainty. Other factors are considered, such as the feasibility of process modification based on Good Manufacturing Practice, and tasks to be improved is identified as the overall output. In a case study on cleaning and sterilization processes, suggestions were produced that could reduce the mean total run time of the processes by up to 40%. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1272–1284, 2018     

Preprocessor-based variability in open-source and industrial software systems: An empirical study

Almost every sufficiently complex software system today is configurable. Conditional compilation is a simple variability-implementation mechanism that is widely used in open-source projects and industry. Especially, the C preprocessor (CPP) is very popular in practice, but it is also gaining (again) interest in academia. Although there have been several attempts to understand and improve CPP, there is a lack of understanding of how it is used in open-source and industrial systems and whether different usage patterns have emerged. The background is that much research on configurable systems and product lines concentrates on open-source systems, simply because they are available for study in the first place. This leads to the potentially problematic situation that it is unclear whether the results obtained from these studies are transferable to industrial systems. We aim at lowering this gap by comparing the use of CPP in open-source projects and industry—especially from the embedded-systems domain—based on a substantial set of subject systems and well-known variability metrics, including size, scattering, and tangling metrics. A key result of our empirical study is that, regarding almost all aspects we studied, the analyzed open-source systems and the considered embedded systems from industry are similar regarding most metrics, including systems that have been developed in industry and made open source at some point. So, our study indicates that, regarding CPP as variability-implementation mechanism, insights, methods, and tools developed based on studies of open-source systems are transferable to industrial systems—at least, with respect to the metrics we considered.