Induced abortion in a Swiss canton from 1990 to 1993: implications for epidemiological surveillance

BACKGROUND: To describe abortion utilization in the Canton of Vaud (Switzerland) and to identify desirable changes in the data collection system to improve the epidemiologic monitoring METHODS: Retrospective survey of the 5600 abortion requests to the Canton Health Authority for resident women between 1990 and 1993. RESULTS: Nine women out of 1000 residents requested an abortion, but the abortion rate was higher among women of foreign origin compared to Swiss women (17/1000 vs. 6/1000, p < 0.0001). The proportion of terminated recognized conceptions was 127/1000, and the ratio of IVG to livebirths was 0.18. The abortion rate was lower during adolescence (6/1000) or after 40 years of age (1.8/1000), whereas the proportion of terminated conceptions was highest at these ages (527/1000 and 312/1000). Abortion utilization in Canton of Vaud is among the lowest. CONCLUSIONS: Although these indicators do reflect a satisfactory accessibility and use of family planning services, improvements could be made. A better knowledge of the causes (motives, contraceptive method, reproductive history) and of the consequences of abortion (psycho-social implications, medical complications) would allow to design more focused prevention strategies and to fit health services to current needs. Updating the 1942 Swiss legislation is also desirable.     

Is the particle deposition in a cell exposure facility comparable to the lungs? A computer model approach

Abstract

Cell exposure experiments at the air-liquid interface (ALI) are used increasingly as indicators for health effects and for the impact of aerosols on the lung. Thereby the aerosol particles are kept airborne and can deposit on a cell surface area similar to the human respiratory tract (RT). However, geometry and air flow rates of an ALI system deviate considerably from the RT. As the tissue-delivered particle dose to the lungs (TD) can hardly be measured, computer models of particle deposition are used here to mimic both the particle deposition at ALI and in the RT. An ALI exposure setup (VitroCell GmbH) for an airflow rate of 100 cm³ min^?1 is selected, where the particle deposition model has been verified experimentally. For the RT we use the hygroscopic lung deposition model of Ferron et al. (2013 Ferron, G. A., S. Upadhyay, R. Zimmermann, and E. Karg. 2013. Model of the deposition of aerosol particles in the respiratory tract of the rat. II. Hygroscopic particle deposition. J. Aerosol Med. Pulm. Drug Deliv. 26 (2):101–19. doi:10.1089/jamp.2011.0965.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). Model runs are performed for the particle deposition and for the deposited particles per surface area in both the ALI and the RT. The results show that the ALI-deposited mass is 1-2 orders of magnitude higher than in the alveolar region, because the surface area of the lung region is substantially larger. A particle size range from 40 to 450 nm is identified, where the ratio of both the deposition in a lung region and the deposition at the ALI varies by a factor less than two. Mean values for this ratio are 31 and 101 for the tracheo-bronchial and the alveolar region, respectively. The same size range is found for the ratio of the deposited particles per surface area in a lung region and at the ALI. For this range the mean surface deposition at the ALI is 23- and 1575-times larger than in the tracheo-bronchial and the alveolar lung region, respectively. The effect is partly compensated by different flow rate and cell size.

Copyright © 2020 American Association for Aerosol Research     

Anatomical structure modeling from medical images

Some clinical applications, such as surgical planning, require volumetric models of anatomical structures represented as a set of tetrahedra. A practical method of constructing anatomical models from medical images is presented. The method starts with a set of contours segmented from the medical images by a clinician and produces a model that has high fidelity with the contours. Unlike most modeling methods, the contours are not restricted to lie on parallel planes. The main steps are a 3D Delaunay tetrahedralization, culling of non-object tetrahedra, and refinement of the tetrahedral mesh. The result is a high-quality set of tetrahedra whose surface points are guaranteed to match the original contours. The key is to use the distance map and bit volume structures that were created along with the contours. The method is demonstrated on computed tomography, MRI and 3D ultrasound data. Models of 170,000 tetrahedra are constructed on a standard workstation in approximately 10s. A comparison with related methods is also provided.     

The plastic-crystalline phase of succinonitrile as a universal matrix for solid-state ionic conductors

Solid ionic conductors are actively sought for their potential application in electrochemical devices, particularly lithium batteries. We have found high ionic conductivity for a large variety of salts dissolved in the highly polar medium based on the plastic-crystal form of succinonitrile (N[triple bond]C[bond]CH(2)[bond]CH(2)[bond]C[triple bond]N). Its high diffusivity, plasticity and solvating power allowed the preparation of a large number of materials with high ionic conductivity, reaching values of 3 mS cm(-1) at 25 degrees C (two orders of magnitude above polymers). Their ease of preparation and processing allowed us to study the influence of the solute on ionic conduction within this medium. Comparisons revealed a dichotomy between plastic crystals and conventional polymer media. The usefulness of these new, easily processed electrolytes was asserted in electrochemical tests with lithium intercalation electrodes.     

Probing Silica Aerogel Structure with Spin-Polarised Helium-3 Gas

We report on systematic low-field NMR measurements on room temperature ³ He gas imbibed into a 98% porous silica aerogel. Laser polarised helium is used to obtain large NMR signals at 0.1 T even for small amounts of gas. We use a multi-echo technique in a controlled magnetic field gradient to characterize spin diffusion. Measurements are carried out for pressures P ranging from 10 mbar to 1 bar (mean free path of free ³ He ranging from 19 to 0.19 m respectively). In a free gas, the damping rate 1/T ₂ of the amplitude of the echoes is checked to be proportional to the known diffusion coefficient (T ₂ P). Damping rates 2–5 times smaller than those in a free gas are measured within the aerogel. This reduction is quite significant at 1 bar, suggesting that ³ He- ³ He and ³ He-silica collisions occur with comparable frequencies at this density. However, a stong dependence of T ₂ on P is still observed at low pressure, revealing a significant reduction of diffusion due to binary atomic collisions even for the lowest gas density. Measurements over such a large range of gas densities indirectely probe collisional effects over a wide range of sizes up to tens of m. In our sample, results are not consistent with a single geometrical mean free path for ³ He-silica collisions.     

Posture and muscular behaviour in emergency braking: An experimental approach

In the field of numerical crash simulations in road safety research, there is a need to accurately define the initial conditions of a frontal impact for the car occupant. In particular, human models used to simulate such impacts barely take into account muscular contracting effects. This study aims to quantify drivers’ behaviour in terms of posture and muscular activity just before a frontal impact.Experiments on volunteers were performed in order to define these conditions, both on a driving simulator and on a real moving car. Brake pedal loads, lower limbs kinematics and muscle activation were recorded.Coupling instantaneous data from both experimental protocols (simulator versus Real car), a standard emergency braking configuration could be defined as (1) joint flexion angles of 96°, 56° and 13° for the right hip, knee and ankle respectively; (2) a maximum brake pedal load of 780 N; (3) a muscular activation of 55% for the anterior thigh, 26% for the posterior thigh, 18% for the anterior leg and 43% for the posterior leg.The first application of this research is the implementation of muscle tone in human models designed to evaluate new safety systems.     

Different ways for grafting ester derivatives of poly(ethylene glycol) onto chitosan: related characteristics and potential properties

The grafting of poly(ethylene glycol) functionalized by ester groups (MeO-PEG-ester) onto chitosan was studied and optimized using different reaction conditions. In a first procedure, the grafting was made from 6-O-triphenylmethyl-chitosan after protection of primary hydroxyl groups and in a second one, it was made directly onto chitosan. NMR spectroscopy was an important tool to study these reactions and the grafting is unequivocally showed up. Moreover, for each procedure, the solubility and surface properties of the obtained copolymers were evaluated and compared.     

Population pharmacokinetics of sirolimus in kidney transplant patients

OBJECTIVE: To characterize the dose-related pharmacokinetics of the immunosuppressant agent sirolimus (formerly rapamycin) in kidney transplant patients by use of two-stage and nonlinear mixed-effect model population methods. METHODS: Patients (n = 36) from three centers (Germany, the United Kingdom, and Sweden) who received steady-state oral doses of cyclosporine (ciclosporin) were assessed after single oral administration of sirolimus at doses of 3, 5, 10, and 15 mg/m2. Plasma and whole blood sirolimus samples were analyzed by a high-performance liquid chromatographic/mass spectrophotometric method. Simultaneous fitting used biexponential functions with intercept/slope or clearance/volume terms, as well as first-order absorption (ka) and a lag-time. RESULTS: The nonlinear mixed-effect model method (P-Pharm) provided a better characterization of sirolimus kinetics, especially for the absorption and distribution phases where fewer data were available per patient. Sirolimus distribution between whole blood and plasma was concentration-independent, with a mean blood/plasma ratio (coefficient of variation) of 30.9 (48.5%). Elimination was not influenced by dose, as shown by estimates of the terminal half-life of 63 hours (27.5%) and apparent oral blood clearance of 8.9 L/hr (38.2%). Sirolimus distribution parameters were influenced by body weight and surface area. Sirolimus was rapidly absorbed, as shown by the absorption lag-time of 0.27 hour (35.1%), and ka of 2.77 hr-1 (48.4%). The concomitant administration of sirolimus and cyclosporine did not reveal any pharmacokinetic interactions. CONCLUSION: This report provides an initial population pharmacokinetics of sirolimus in kidney transplant recipients receiving cyclosporine concurrently. Sirolimus blood and plasma pharmacokinetics were biexponential and linear for doses from 3 to 15 mg/m2. No pharmacokinetic interaction was found between sirolimus and cyclosporine.     

Investigation of electrostrictive polymer efficiency for mechanical energy harvesting

The purpose of this paper is to propose new means for harvesting energy using electrostrictive polymers. Recent trends in energy conversion mechanisms have demonstrated the abilities of electrostrictive polymers for converting mechanical vibrations into electricity. In particular, such materials present advantageous features such as a high productivity, high flexibility, and ease of processing; hence, the application of these materials for energy harvesting purposes has been of significant interest over the last few years. This paper discusses the development of a model that is able to predict the energy harvesting capabilities of an electrostrictive polymer. Moreover, the energy scavenging abilities of an electrostrictive composite composed of terpolymer poly(vinylidenefluoride-trofluoroethylene- chlorofluoroethylene) [P(VDF-TrFE-CFE)] filled with 1 vol% carbon black (C) is evaluated. Experimental measurements of the harvested power and current have been compared with the theoretical behavior predicted by the proposed model. A good agreement was observed between the two sets of data, which consequently validated the proposed modeling to optimize the choice of materials. It was also shown that the incorporation of nanofillers in P(VDF-TrFE-CFE) increased the harvested power.