Apoptosis and resistance to daunorubicin in human leukemic cells

We compared test methods based on specific mechanisms of daunorubicin (DNR) resistance to more global procedures. Assessment of P-glycoprotein (P-gp) expression and function by means of immunocytochemistry, DNR accumulation, and modulation of resistance and accumulation by the P-gp inhibitor cyclosporin A (CsA) were selected as parameters for multidrug resistance (MDR). On the other hand, we used the MTT assay and measured apoptosis and proliferative activity (S- and G2M-phases of the cell cycle) by flow cytometry. Validation of test methods was achieved for four leukemic cell lines (HL-60, KG-1a, K562/WT, K562/ADM). This battery of tests was then applied to mononuclear cells (MNC) from 18 leukemic patients. Low proficiency of MNC to undergo apoptosis and low proliferative activity rather than P-gp-mediated MDR correlated with DNR resistance as measured by the MTT assay. Bell-shaped dose-response curves for apoptosis, however, which reflect a switch from the apoptotic to the necrotic death mode with increasing cellular damage tend to limit practicability in clinical testing, because appropriate dose range and time points need to be explored. Thus, measurement of apoptosis by flow cytometry may be less convenient than the MTT assay for determination of chemosensitivity, if clinical samples with unknown patterns of responsiveness are to be tested. Spontaneous apoptosis in untreated MNC following 24 h incubation in vitro correlated significantly with DNR sensitivity in the MTT assay. A lack of essential viability factors (eg growth factors or cytokines) in vitro which are known to prevent apoptosis may contribute to DNR sensitivity.     

Expressing aspectual interactions in design: evaluating three AOM approaches in the slot machine domain

In the context of an industrial project, we evaluated the implementation of the software of a casino slot machine. This software has a significant amount of crosscutting concerns that depend on and interact with each other as well as with the modular concerns. We therefore wished to express our design using an appropriate aspect-oriented modeling approach. We therefore evaluated three candidate methodologies: Theme/UML, WEAVR, and RAM to establish their suitability. Remarkably, only the last of the three has shown to allow an adequate expression of the interactions, albeit not fully explicit. The first two fall short because half of the interaction types cannot be expressed at all while the other half need to be expressed using a work-around that hides the intention of the design. Neither does RAM allow a fully explicit expression of interactions, but it would be the most adequate approach for the slot machine case.     

Conservative treatment of femoral shaft fractures in patients with total hip arthroplasty

The proposed two-factor structure of the Psychopathy Checklist (Revised) was assessed by confirmatory factor analyses on a sample of 376 community and prison based methadones maintenance patients. Confirmatory factor analyses indicated that the two-factor model proposed by previous researchers did not fit well with the data from this population. Exploratory analyses extracted five interpretable factors, three psychological factors (glibness/manipulative, callousness, irresponsibility), and two behavioral factors (criminal behaviors, promiscuity), which accounted for 61% of the variance. The data provided support for the psychometric reliability of the PCL-R, as indicated by a Chronbach's alpha of 0.83, weighted kappas for concordance between raters ranging from 0.51 to 1.00, and 100% agreement on diagnoses of psychopathy between raters. The data indicate that a two-factor structure does not adequately capture the dimensions of psychopathy in this population. While the factors do fall into distinct psychological and behavioral dimensions, more than two general factors are required to describe the dimensions of psychopathy.     

Internal fixation of the spine in traumatic and scoliotic cases. The potential of pedicle screws

Internal fixation techniques are in common used to stabilize vertebral fractures and correct severe scoliosis. Consolidation of injured vertebrae with neighbouring intact vertebra is the goal in the former case whilst fusion of the vertebrae in a corrected position is aimed at in the latter case. Degenerative spine diseases are not considered in this paper. Classical instrumentation consists of rods (e.g., Cotrel-Dubousset, Harrington, Luque-Galveston) attached to the bone by means of hooks or wires. More recently, transpedicular screws are introduced as an alternative bone/implant interface. Comparing the results of several studies, the posterior pedicle screw based devices demonstrate the ability to produce the most rigid constructs. However, the insertion of pedicle screws implicates a relatively high complication risk and its success strongly depends on the experience of the surgeon. Incorrect drilled holes or malplacement of the screws can result in nerve root injuries and fracture of the pedicle. Studies reported complication ratios up to 30% with substantial neurological implications. A certain degree of automation of the critical actions may be necessary to enhance the safety of pedicle screw insertion. Two techniques of computer assisted spine surgery are compared. Both techniques permit a computer assisted surgical planning based on CT images. During operation the first system permanently observes the position of the drill relative to the spine and informs the surgeon on the deviation of the actual drill path to the planned drill path. The second system uses a pre-operative surgical planning to design and construct a mechanical drill guide, fitting perfectly on the patient's spine.     

Nuclear accident simulation in a 1/6 scale model of the SNR-300 fast breeder reactor

In the frame of the licensing of the SNR-300 fast breeder reactor an HCDA has been investigated both by theoretical and experimental means. The latest phase of this programme was the simulation of a HCDA in a very well instrumented 1/6 scale model of the SNR-300 vessel. The Bethe-Tait accident was simulated by a slow burning charge. In order to check the reliability of the theoretical means allowing for an evaluation of these accidents, the German authorities wanted to receive, before the shot, a theoretical precalculation report showing the main permanent deformations and responses of the pressure and strain gauges versus time.This paper compares and comments on the most meaningful results of this experiment with the SURBOUM-II precalculated estimations.     

A semi-active milling procedure in view of preparing implantation beds in robot-assisted orthopaedic surgery

Bone cutting in total joint reconstructions requires a high accuracy to obtain a well-functioning and long-lasting prosthesis. Hence robot assistance can be useful to increase the precision of the surgical actions. A drawback of current robot systems is that they autonomously machine the bone, in that way ignoring the surgeon's experience and introducing a safety risk. This paper presents a semi-active milling procedure to overcome that drawback. In this procedure the surgeon controls robot motion by exerting forces on a force-controlled lever that is attached to the robot end effector. Meanwhile the robot constrains tool motion to the planned motion and generates a tool feed determined by the feed force that the surgeon executes. As a case study the presented milling procedure has been implemented on a laboratory set-up for robot-assisted preparation of the acetabulum in total hip arthroplasty. Two machining methods have been considered. In the first method the surgeon determines both milling trajectory and feed by the forces that he/she executes on the force-controlled lever. In the second method the cavity is machined contour by contour, and the surgeon only provides the feed. Machining experiments have shown that the first method results in large surface irregularities and is not useful. The second method, however, results in accurate cavity preparation and has therefore potential to be implemented in future robot systems.     

The influence of the carbon precursor,carbon feed rate and helium gas flow rate on the synthesis of fullerenes from carbon powder in an entrained flow 3-phase AC plasma reactor operating at atmospheric pressure

We studied an entrained flow 3-phase AC plasma reactor operating at atmospheric pressure with helium for the synthesis of fullerenes from different carbon powder precursors through an evaporation–condensation process. A parametric study focusing on gas flow rate and carbon powder feed rate was carried out using three commercial carbon materials: Y50A acetylene black from SN2A, E 250 carbon black from TIMCAL, and KS 4 graphite powder from TIMCAL. This study revealed a strong dependence of these parameters with fullerene yield and rate of fullerene production. It also revealed the key role of the carbon black purity. The best results were obtained using acetylene black Y50 A, for which a rate of fullerene production of the order of 17 g h^?1 corresponding to a 480 g h^?1 carbon feed rate at 3.6% fullerene content (C60 + C70) were obtained. The specific energy input defined as the plasma power related to carbon precursor feed rate and rate of fullerene production were estimated to 0.039 kWh g^?1 and 1.11 kWh g^?1 respectively.     

On the static and dynamic selectivity study of a sodium sensor

This paper describes the measurement of selectivity coefficients of a potentiometric sodium sensor based on a ceramic membrane and its response to interfering ions. An acquisition subsystem is realized around the 68MC701. Microcontroller to drive the analog part which multiplexes four channels at high input impedance (more than 1000 GΩ). The system is used for data acquisitions from ions sensors with different realizations. The output voltages are plotted against time to show the evolution of the output signals for different interfering ions (Potassium, Calcium, and Lithium). Hence, four sensors with membranes sintered at 900, 1000, 1150, and 1200°C have been characterized. An experimental setup has been realized and adapted to the subsystem to study the transient interferences. Experimental results are given to show the effect of disturbance in the static and dynamic cases