Electromagnetic compatibility aspects of active robotic systems for surgery: the robotic prostatectomy experience

This case describes ventricular proarrhythmia as a result of a synchronized internal atrial defibrillation shock in a 29-year-old man with Ebstein's anomaly referred for radiofrequency ablation of a right posterior accessory pathway. During the electrophysiologic study, atrial fibrillation was induced and 3/3 msec shocks of various strengths were delivered between two decapolar defibrillation catheters in the coronary sinus and right atrial appendage. A 2.0-J biphasic shock synchronized to an R wave after a short-long-short ventricular cycle length pattern with a preshock coupling interval of 245 msec induced ventricular fibrillation, which was externally defibrillated with 200 J. This observation has implications for the development of implantable atrial defibrillators.     

Electronic and phonon properties of the full-Heusler alloys X<Subscript>2</Subscript>YAl (X = Co,Fe and Y = Cr,Sc): a density functional theory study

First-principle calculations have been carried out on the structural, electronic, elastic, and phonon properties of the full-Heusler alloys X₂YAl (X = Co, Fe and Y = Cr, Sc). The calculations predict that the Fe₂CrAl and Co₂CrAl are half-metallic ferromagnets at the equilibrium lattice constant with a minority-spin energy gap of 0.2912 and 0.668 eV, respectively. Fe₂ScAl exhibit a gap in the majority density of states, with a few states at the Fermi level and about 0.217 states eV^?1, unlike the other Heusler compounds; due to this, it is considered a false half metal, and Co₂ScAl is considered a non-magnetic compound. The elastic constants were derived from the slopes of the acoustic branches in the phonon-dispersion curve. The calculated lattice constants, bulk modulus, and first-order pressure derivative of the bulk modulus are reported for the L2₁ structure and compared with previous values. Phonon-dispersion curves were obtained using the first-principle linear-response approach of the density-functional perturbation theory. The specific heat capacity at a constant volume C _V of X₂YAl (X = Co, Fe and Y = Cr, Sc) alloys is calculated and discussed.     

How accurately do drivers evaluate their own driving behavior? An on-road observational study

Self-assessment of driving skills became a noteworthy research subject in traffic psychology, since by knowing one's strenghts and weaknesses, drivers can take an efficient compensatory action to moderate risk and to ensure safety in hazardous environments. The current study aims to investigate drivers’ self-conception of their own driving skills and behavior in relation to expert evaluations of their actual driving, by using naturalistic and systematic observation method during actual on-road driving session and to assess the different aspects of driving via comprehensive scales sensitive to different specific aspects of driving. 19–63 years old male participants (N = 158) attended an on-road driving session lasting approximately 80 min (45 km). During the driving session, drivers’ errors and violations were recorded by an expert observer. At the end of the driving session, observers completed the driver evaluation questionnaire, while drivers completed the driving self-evaluation questionnaire and Driver Behavior Questionnaire (DBQ). Low to moderate correlations between driver and observer evaluations of driving skills and behavior, mainly on errors and violations of speed and traffic lights was found. Furthermore, the robust finding that drivers evaluate their driving performance as better than the expert was replicated. Over-positive appraisal was higher among drivers with higher error/violation score and with the ones that were evaluated by the expert as “unsafe”. We suggest that the traffic environment might be regulated by increasing feedback indicators of errors and violations, which in turn might increase the insight into driving performance. Improving self-awareness by training and feedback sessions might play a key role for reducing the probability of risk in their driving activity.     

Cleaning Method of InSb [-1-1-1] B of n- InSb [111] A/B for growth of epitaxial layers by liquid phase epitaxy

The crystal structure of InSb [111] A/B surfaces shows that this structure is polarized. This means that the surfaces of InSb [111] A and InSb [1 1 1] B contain two different crystallized directions and they have different physical and chemical properties. Experiments were carried out on the InSb [111] A/B surfaces, showing that tartaric acid etchant could create a very smooth surface on the InSb [1 1 1] B without any traces of oxides and etch pit but simultaneously create etch pit on InSb [111] A surfaces. After lapping and polishing, some particles remained on the InSb [1 1 1] B surface, they could not be removed easily by standard cleaning process and if these particles remain on the surface of the substrate, the growth layer was not uniform and some island-like regions were observed. The purpose of this work is to remove these particles on the InSb [1 1 1] B surface. Some morphology images of both surfaces, InSb [111] A/B, will be presented.     

Response of preimplantation murine embryos to heat shock as modified by developmental stage and glutathione status

Objectives were to characterize developmental changes in response to heat shock in the preimplantation mouse embryo and to evaluate whether ability to synthesize glutathione is important for thermal resistance in mouse embryos. Heat shock (41 degrees C for 1 or 2 h) was most effective at disrupting development to the blastocyst stage when applied to embryos at the 2-cell stage that were delayed in development. Effects of heat shock on ability of embryos to undergo hatching were similar for 2-cell, 4-cell, and morula stage embryos. The phenomenon of induced thermotolerance, for which exposure to a mild heat shock increases resistance to a more severe heat shock, depended upon stage of development and whether embryos developed in vitro or in vivo. In particular, induced thermotolerance was observed for morulae derived from development in vivo but not for 2-cell embryos or morulae that developed in culture. Administration of buthionine sulfoximine to inhibit glutathione synthesis did not increase thermal sensitivity of 2-cell embryos or morulae but did reduce subsequent development of 2-cell embryos at both 37 degrees and 41 degrees C. In summary, changes in the ability of 2-cell through morula stages to continue to develop following a single heat shock were generally minimal. However, 2-cell embryos delayed in development had reduced thermal resistance, and therefore, maternal heat stress may be more likely to cause mortality of embryos that are already compromised in development. There were also developmental changes in the capacity of embryos to undergo induced thermotolerance. Glutathione synthesis was important for development of embryos but inhibition of glutathione synthesis did not make embryos more susceptible to heat shock.     

Human serum albumin adsorption on poly[(glycidyl methacrylate)‐co‐(methyl methacrylate)] beads modified with a spacer‐arm‐attached L‐histidine ligand

Poly(GMA/MMA) beads were synthesized from glycidyl methacrylate (GMA) and methyl methacrylate (MMA) in the presence of a cross‐linker (i.e. ethyleneglycol dimethacrylate) (EGDMA) via suspension polymerization. The epoxy groups of the poly(GMA/MMA) beads were converted into amino groups with either ammonia or 1,6‐diaminohexane (i.e. spacer‐arm). An L ‐histidine ligand was then covalently immobilized on the aminated (poly(GMA/MMA)‐AH) and/or the spacer‐arm attached (poly(GMA/MMA)‐SAH) beads using glutaric dialdehyde as a coupling agent. Both affinity adsorbents were used in human serum albumin (HSA) adsorption/desorption studies under defined pH, ionic strength or temperature conditions in a batch reactor. The spacer‐arm attached affinity adsorbent resulted in an increase in the adsorption capacity to HSA when compared to the aminated counterpart (i.e. poly(GMA/MMA)‐AH). The maximum adsorption capacities of the affinity adsorbents were found to be significantly high, i.e. 43.7 and 80.2 mg g^?1 (of the beads), while the affinity constants, evaluated by the Langmuir model, were 3.96 × 10^?7 and 9.53 × 10^?7 mol L^?1 for poly(GMA/MMA)‐AH and poly(GMA/MMA)‐SAH, respectively. The adsorption capacities of the affinity adsorbents were decreased for HSA by increasing the ionic strength, adjusted with NaCl. The adsorption kinetics of HSA were analysed by using pseudo‐first and pseudo‐second‐order equations. The second‐order equation fitted well with the experimental data. Copyright © 2005 Society of Chemical Industry     

具有壁面Weis-Fogh机构流体动力多重网格并行计算

应用多重网格区域分裂并行计算方法研究具有壁面Weis-Fogh机构绕流，将二维物理平面流动区域变换为矩形区域，推导出流函数的多重网格差分计算格式，编制出并行计算程序。全部计算在英国London大学ITL并行计算中心完成。结果表明，多重网格并行计算具有较高的加速比，绕机翼的环量计算值与理论吻合。