94 research outputs found

    Sensor Modeling Realization Based on Fruit Fly Optimization Algorithm

    Get PDF
    The structural parameter optimization model of binocular stereo vision sensor was first built using the optimum regression design to improve its measurement precision in this study. Then, the optimization model was solved by Fruit Fly Optimization Algorithm (FOA). The measurement precision of binocular stereo visual sensor has been greatly improved through FOA optimization. Thus, it can obtain better results than traditional methods

    Computational Optogenetics: Empirically-Derived Voltage- and Light-Sensitive Channelrhodopsin-2 Model

    Get PDF
    Channelrhodospin-2 (ChR2), a light-sensitive ion channel, and its variants have emerged as new excitatory optogenetic tools not only in neuroscience, but also in other areas, including cardiac electrophysiology. An accurate quantitative model of ChR2 is necessary for in silicoprediction of the response to optical stimulation in realistic tissue/organ settings. Such a model can guide the rational design of new ion channel functionality tailored to different cell types/tissues. Focusing on one of the most widely used ChR2 mutants (H134R) with enhanced current, we collected a comprehensive experimental data set of the response of this ion channel to different irradiances and voltages, and used these data to develop a model of ChR2 with empirically-derived voltage- and irradiance- dependence, where parameters were fine-tuned via simulated annealing optimization. This ChR2 model offers: 1) accurate inward rectification in the current-voltage response across irradiances; 2) empirically-derived voltage- and light-dependent kinetics (activation, deactivation and recovery from inactivation); and 3) accurate amplitude and morphology of the response across voltage and irradiance settings. Temperature-scaling factors (Q10) were derived and model kinetics was adjusted to physiological temperatures. Using optical action potential clamp, we experimentally validated model-predicted ChR2 behavior in guinea pig ventricular myocytes. The model was then incorporated in a variety of cardiac myocytes, including human ventricular, atrial and Purkinje cell models. We demonstrate the ability of ChR2 to trigger action potentials in human cardiomyocytes at relatively low light levels, as well as the differential response of these cells to light, with the Purkinje cells being most easily excitable and ventricular cells requiring the highest irradiance at all pulse durations. This new experimentally-validated ChR2 model will facilitate virtual experimentation in neural and cardiac optogenetics at the cell and organ level and provide guidance for the development of in vivo tools

    Surgical wound infection following open humeral fracture caused by Mycobacterium houstonense: a case report

    No full text
    Abstract Background Historically Mycobacterium houstonense belongs to the unnamed third biovariant complex of the Mycobacterium fortuitum group, which are sorbitol positive. To date, there have been few reports of human infection induced by M. houstonense worldwide. Case presentation We describe the case of a 68-year-old man with surgical wound infection, following an open humeral fracture, caused by M. houstonense and Escherichia coli. An implant bone plate had been embedded for internal fixation during surgery on the humeral fracture previously. A week later E. coli was isolated from the skin wound secretions. Cefoperazone-sulbactam was used for treatment for two weeks but the infection was not controlled, with a subsequent risk of deep wound infection. External fixation of the fracture was then performed instead of internal fixation. Ten days later, M. houstonense was isolated from new wound secretions. M. houstonense was identified by the molecular sequencing method. The TREK Diagnostic System was used to test the susceptibility to antibiotics by the microbroth dilution method. Levofloxacin and amikacin were used for treatment according to the results of the susceptibility test and the patient’s condition obviously improved. Conclusion To the best of our knowledge, this is the first case in China of human surgical wound infection caused by M. houstonense following open humeral fracture. The combination of levofloxacin and amikacin was effective in the treatment of M. houstonense infection

    Leptotrichia trevisanii bacteremia in a woman with systemic lupus erythematosus receiving high-dose chemotherapy

    No full text
    Abstract Background Leptotrichia species are aerotolerant, Gram-negative fusiform bacteria. Cases of bacteremia caused by Leptotrichia trevisanii in immunocompromised patients have been rarely reported. Case presentation A 33-year-old female with systemic lupus erythematosus (SLE) was admitted to the department of rheumatology with bleeding from a mucosal ulcer. One month previously, she had visited our hospital and begun to receive methotrexate therapy, but mis-dosed for nearly 1 month at home. Methotrexate toxicity resulted in a severe oral ulcer and bone marrow suppression. On day-7 of hospital admission, she developed a fever, and Gram-negative rods (Leptotrichia trevisanii) were detected in blood cultures. She was diagnosed with methotrexate poisoning followed by L. trevisanii bacteremia. After antibiotic and detoxification therapy, she recovered from bacteremia, and the oral ulcer and bone-marrow suppression improved obviously. Conclusions This is the first reported case of Leptotrichia trevisanii bacteremia in a SLE patient who took mis-dosed an immunosuppressant and had an oral mucosal lesion

    Rapid screening and cultivation of oleaginous microorganisms

    No full text
    282-289Oleaginous microbial strains were cultivated to identify the best oil-producing strain amongst Yarrowia lipolytica (CGMCC 2.1398), Lipomyces starkeyi (CGMCC 2.1608), Rhodosporidium toruloides (CGMCC 2.1389), Mortierella isabellina (CGMCC 3.3410), Cunninghamella blakeleana (CGMCC 3.970), and Mycobacterium QJ311. A method for rapid determination of oil content and fatty acid composition was established to identify the optimum oil-producing strains. This method had a relative standard deviation of 4.09%, an average recovery ratio of 97.09% and a detection limit of 0.1–1.0 g. Mortierella isabellina CGMCC 3.3410 was identified as the best oil-producing strain amongst the six strains tested, with a total biomass of 75 g/10 L and a lipid content of 35%. A rapid screening method of oleaginous microorganisms is discussed for the first time

    Study on the vertical bearing performances of piles on karst cave

    No full text
    Abstract Caves affected the load transfer mechanism of bridge pile foundation, and then the safety of the bridge was threatened. This study was to investigate the effect of karst cave under bridge pile foundations on the vertical bearing characteristics of bridge pile foundations by static load test, finite element analysis and mechanical model. The settlement of the pile was measured by displacement meter, and the axial force were measured by stress gauges in the test. The load-settlement, the axial force, the unit skin friction and the ratios of side and tip resistances were compared with the result of the simulation. Then sixteen conditions were selected in finite element analysis, one of them was a conventional pile not on cave. The others were about five kinds of height, five kinds of span and six kinds roof’s thickness of the cave. The simply supported and fixed wide beam were established to calculate the allowance roof thickness. The results reveal that when the cave span is greater than 9 m × 9 m or the roof thickness is less than 2 D (pile diameter), the stress and deformation of piles are significantly affected
    • …
    corecore