The effect of placenta location on the safety of pregnant driver and her fetus

Placental abruption accounts for more than half of fetal mortality in automobile collisions. In most of the pregnancies, placenta is located at the fundus position of the uterus. However, in real life, placenta can also be found at different locations in the uterus. The goal of this study is to investigate whether the location of the placenta in the uterus of pregnant driver has a role on the risk of placental abruption in motor vehicle accidents. In addition to the most common fundus position, four other placental locations, namely anterior, posterior, lateral left and lateral right, are considered within the computational pregnant driver model ‘Expecting’, and used in collision simulations with impact severities from 15 to 30 kph with 5-kph increments. Scenarios also include four cases where the pregnant driver is fully restrained with three-point seatbelt and airbag, three-point seatbelt only, airbag only and no restraint at all. The maximum strains developed in the utero-placental interface of the model in this set of 64 simulations together with the fundus-location simulations are determined and compared in order to investigate the effect of placental location on the placental abruption prediction. Placenta located at anterior position is found to be at higher risk than other placental positions considered in this investigation. The results demonstrate that being fully restrained is the safest option and the three-point seatbelt is the most effective restraint system whilst the airbag makes a small contribution to the protection of pregnant driver and her fetus

Graphene microwave transistors on sapphire substrates

We have developed metal-oxide graphene field-effect transistors (MOGFETs) on sapphire substrates working at microwave frequencies. For monolayers, we obtain a transit frequency up to ~ 80 GHz for a gate length of 200 nm, and a power gain maximum frequency of about ~ 3 GHz for this specific sample. Given the strongly reduced charge noise for nanostructures on sapphire, the high stability and high performance of this material at low temperature, our MOGFETs on sapphire are well suited for a cryogenic broadband low-noise amplifier

Hybrid foetus with an FE head for a pregnant occupant model for vehicle safety investigations

‘Expecting’, a computational pregnant occupant model, developed to simulate the dynamic response to crash impacts, possesses anthropometric properties of a fifth percentile female at around the 38th week of pregnancy. The model is complete with a finite element uterus and a multi-body foetus which is a novel feature in models of this kind. In this paper, the effect of incorporating a foetus with a finite element head into ‘Expecting’ is investigated. The finite element head was developed using detailed anatomic geometry and projected material properties. Then it was integrated with the ‘Expecting’ model and validated using the lap belt loading and the rigid bar impact tests. The model is then used to simulate frontal impacts at a range of crash severities with seatbelt and airbag, seatbelt only, airbag only as well as no restraint cases to investigate the risk of placental abruption and compare it with the model featuring the original multi-body foetus. The maximum strains developed in the utero-placental interface are used as the main criteria for foetus safety. The results show comparable strain levels to those from the multi-body foetus. It is, therefore, recommended to use the multi-body foetus in simulations as the computation time is more favourable

The effect of including a fetus in the uterus model on the risk of fetus mortality through drop test and frontal crash simulations

© 2016 Informa UK Limited, trading as Taylor & Francis Group Computational modelling is an effective way of estimating the risk of injuries and fatalities in road traffic accidents. Computational pregnant occupant modelling has an additional important role in the investigation of the risk of fetus mortality in crash test simulations. In this paper, the effect of including the fetus in the uterus of the pregnant occupant model is investigated. First, isolated drop test simulations with the uterus of the computational pregnant occupant model, ‘Expecting’, with and without a fetus are used to show the effect of the presence of fetus in the uterus model. Then ‘Expecting’ with and without the fetus is used with varying levels of restraint system use, such as fully restrained, ‘seatbelt only’, ‘airbag only’ and ‘no restraint’, in frontal crash simulations, representing five levels of impacts. Maximum strains developed in the uteroplacental interface with and without a fetus are compared in every case. Both simulations predict higher risks of placental abruption when the fetus is included in the model. Simulations with and without a fetus model show that inclusion of a 38-week fetus model causes higher strains in the placental region of uterus

Proton tracking in a high-granularity Digital Tracking Calorimeter for proton CT purposes

Radiation therapy with protons as of today utilizes information from x-ray CT in order to estimate the proton stopping power of the traversed tissue in a patient. The conversion from x-ray attenuation to proton stopping power in tissue introduces range uncertainties of the order of 2-3% of the range, uncertainties that are contributing to an increase of the necessary planning margins added to the target volume in a patient. Imaging methods and modalities, such as Dual Energy CT and proton CT, have come into consideration in the pursuit of obtaining an as good as possible estimate of the proton stopping power. In this study, a Digital Tracking Calorimeter is benchmarked for proof-of-concept for proton CT purposes. The Digital Tracking Calorimeteris applied for reconstruction of the tracks and energies of individual high energy protons. The presented prototype forms the basis for a proton CT system using a single technology for tracking and calorimetry. This advantage simplifies the setup and reduces the cost of a proton CT system assembly, and it is a unique feature of the Digital Tracking Calorimeter. Data from the AGORFIRM beamline at KVI-CART in Groningen in the Netherlands and Monte Carlo simulation results are used to in order to develop a tracking algorithm for the estimation of the residual ranges of a high number of concurrent proton tracks. The range of the individual protons can at present be estimated with a resolution of 4%. The readout system for this prototype is able to handle an effective proton frequency of 1 MHz by using 500 concurrent proton tracks in each readout frame, which is at the high end range of present similar prototypes. A future further optimized prototype will enable a high-speed and more accurate determination of the ranges of individual protons in a therapeutic beam.Comment: 21 pages, 8 figure

Is the United States Claims Court Constitutional?

This article will deal with two major constitutional problems that have resulted from the creation of the Claims Court. The first issue is the constitutionality of the appointment of existing Court of Claims Commissioners to be judges on the Claims Court during a four-year transition period. By legislatively designating the persons who are to serve as judges on the new court, Congress has usurped the presidential appointment power. The second issue relates to the constitutional status of the Claims Court. The Court of Claims which it replaces was created under article III of the Constitution, and the judges on it were therefore entitled to life tenure and salaries that could not be reduced during their terms in office. The new Claims Court, on the other hand, is designated by Congress as an article I court; the judges are to be appointed for only fifteen year terms, and their salaries are subject to control by Congress. The new court exercises full judicial authority, however, and has jurisdiction over cases of national importance in which the government of the United States has a great financial stake. Although the analysis of this issue is far from simple, this author concludes that Congress has exceeded its constitutional authority by failing to comply with the requirements of article III of the Constitution in establishing the Claims Court

BRAF V600E mutations in urine and plasma cell-free DNA from patients with Erdheim-Chester disease.

Erdheim-Chester disease (ECD) is a rare histiocytosis with a high prevalence of BRAF V600E mutation (>50% of patients). Patients with BRAF-mutant ECD can respond to BRAF inhibitors. Unfortunately, the lack of adequate archival tissue often precludes BRAF testing. We hypothesized that cell-free DNA (cfDNA) from plasma or urine can offer an alternative source of biologic material for testing. We tested for BRAF V600E mutation in cfDNA from the plasma and urine of 6 ECD patients. In patients with available archival tissue, the result of BRAF mutation analysis was concordant with plasma and urine cfDNA results in all 3 patients (100% agreement, kappa 1.00). In all 6 patients, BRAF mutation analysis of plasma and urine cfDNA was concordant in 5 of 6 patients (83% agreement, kappa 0.67). Testing for BRAF V600E mutation in plasma and urine cfDNA should be further investigated as an alternative to archival tissue mutation analysis