In vivo platelet and T-lymphocyte activities during pulmonary tuberculosis

Platelets have been suggested to play a role in the inflammatory response, including defence against bacteria. The aims of this study were to determine in vivo platelet activity during the clinical course of pulmonary tuberculosis and to investigate whether or not there is a correlation between the magnitude of platelet activation and the extent of the pulmonary disease. T-lymphocyte activity was also analysed in the patients. Platelet factor-4 (PF4) and soluble interleukin-2 receptor-alpha (sIL-2Ralpha) concentrations were used as markers of platelet and T-lymphocyte activation, respectively. Twenty-five patients with pulmonary tuberculosis were studied. Fifteen healthy subjects served as a control group. The levels of both sIL-2Ralpha (3,000+/-1,948 pg x mL(-1)) and PF4 (103.1+/-6.7 IU x mL(-1)) were significantly higher in the patients with tuberculosis than in the control group (984+/-360 pg x mL(-1) and 78.2+/-23.9 IU x mL(-1), respectively) (Mann-Whitney U-test, p<0.001 for both comparisons). The plasma PF4 levels were found to be well correlated with the extent of pulmonary lesions on chest radiography (the Spearman's bivariate correlation analysis, r=0.65, p<0.001). However, sIL-2Ralpha concentrations did not correlate with the extent of disease. In conclusion, it has been suggested that platelet and T-lymphocyte activation occurs during pulmonary tuberculosis. The good correlation between platelet activation and the extent of pulmonary tuberculosis might be ascribed to a pathophysiological role of platelets in pulmonary tuberculosis.     

Hydatid disease of the CNS: imaging features

OBJECTIVE: The objective of this study was to assess the usefulness of dynamic single-shot MR cholangiopancreatography in the evaluation of the morphology and contractility of the normal Vaterian sphincter complex and to assess whether i.v. injection of glucagon can improve visualization. SUBJECTS AND METHODS: Sixty patients without signs of Vaterian sphincter complex dysfunction were studied. A fast single-shot MR imaging sequence was used to obtain 20 consecutive images of the Vaterian sphincter complex during successive episodes of breathholding. In patients of group A (n = 30), 10 images were obtained before and 10 after i.v. administration of a sphincter-relaxing agent (glucagon). In the patients of group B (n = 30), no glucagon was administered. The degree of visualization of the Vaterian sphincter complex was assessed. RESULTS: Overall, the morphology and contractility of the Vaterian sphincter complex was adequately assessed in 57 patients (95%). However, the number of repetitions required to obtain this result varied greatly (mean, seven; range, two to 18). Glucagon had no apparent effect on the visibility of the most distal portion of the common bile duct. CONCLUSION: Nonvisualization of the most distal portion of the common bile duct on MR cholangiopancreatography studies is a normal variant that can simulate disease. Obtaining serial breath-hold images using a single-shot technique is helpful to avoid diagnostic errors.     

Silent cerebral lesions on magnetic resonance imaging in subjects with coronary artery disease

OBJECTIVES: Critical vascular surgery of the brain or the heart occasionally requires total cessation of the circulatory system. Profound hypothermia is used to protect the brain from ischaemic injury. This study explores the use of microdialysis to measure metabolic indices of ischaemia: glutamate, lactate, and pH, and cerebral temperature during profound hypothermia and circulatory arrest. METHODS: Effluent from a microdialysis catheter placed in the cerebral cortex of three patients undergoing complete circulatory arrest was continuously sampled. Samples were pooled over 10 minute periods and glutamate and lactate concentrations were measured postoperatively. Brain temperature and pH were measured on line intraoperatively. Electroencephalography and monitoring of somatosensory evoked potentials and brainstem auditory evoked potentials were simultaneously carried out. RESULTS: Patient 1 had normal glutamate and lactate. PH was 6.75 to 6.85 and increased to 6.9 after warming ensued. Patient 2 had raised glutamate and lactate during most measurements. The glutamate concentrations peaked at 305 microM/l at the start of the measurements and fell below 20 microM/l after warming. The lactate concentrations peaked at 680 microM/l before cooling, rose to 1040 microM/l during the cooling process, decreased to 212 microM/l during circulatory arrest, and rose again to 620 microM/l after warming. The pH started at 7.06 and continued a downward course until stabilising at a pH of 6.5 after circulatory arrest. Patient 3 had a transient, mild increase in glutamate and lactate during the cooling and warming period. pH was stable throughout. CONCLUSION: Microdialysis combined with temperature and pH measurements of the cerebral cortex promises to be an important tool in detecting cerebral ischaemia. Further studies are needed to validate our findings and test the feasibility of modifying ischaemic changes.     

Interictal SPECT with Tc-99m HMPAO studies in migraine patients

BACKGROUND: Creating a defunctioning stoma for anorectal disease in patients in whom no resection or anastomosis is required appears eminently suited for laparoscopic techniques, with the intended advantages of early recovery, reduced pain, and avoidance of a laparotomy. OBJECTIVES: The study contained herein was undertaken to determine the feasibility of laparoscopic defunctioning stoma formation using a three-port technique (including one at the stoma site) and to compare initial results with a historical control group. METHODS: Duration of operation (anesthetic plus surgery), the time to tolerance of a liquid and then a solid diet, time to passage of flatus and feces, patient morphine requirements in the first 48 hours, and day of discharge were documented. RESULTS: Nineteen laparoscopic stomas were attempted (3 converted to open) and 23 open stomas were formed in the control group. The laparoscopic stoma group had lower morphine requirements (mean, 47.7 vs. 89.9 mg; P < 0.01), an earlier tolerance of both liquid (mean, 2.1 vs. 3.7 days; P < 0.01) and solid diets (mean, 3.6 vs. 5.5 days; P < 0.001), and an earlier time to passage of both flatus (mean, 2.2 vs. 3.6 days; P < 0.001) and feces (mean, 3.7 vs. 5.6 days; P < 0.001). Operating time was longer for the laparoscopic group (mean, 176 vs. 104 minutes; P < 0.001), whereas median time to discharge from hospital was shorter (median, 8 vs. 11 days; P = 0.014). Postoperative 30-day morbidity occurred in 1 of 19 laparoscopic group patients and 4 of 23 open group patients. CONCLUSIONS: In this select group of patients requiring defunctioning stoma only, laparoscopic surgery is feasible and safe and may have advantages over open procedures of less pain, earlier tolerance of diet, earlier return of bowel function, and a shorter median length of stay.     

Room-Temperature Mechanochemical Synthesis of W2B5 Powders

The mechanochemical synthesis of W₂B₅ powders was successfully carried out at room temperature. WO_2.72, B₂O₃ and Mg powder blends were mixed to form batches according to the metallothermic reduction of WO_2.72 and B₂O₃ with Mg, which were subsequently mechanically alloyed (MA) using a Spex mill at different durations to constitute W₂B₅ + MgO as final products. Following mechanochemical synthesis, MgO was removed from the system by leaching the powders with HCl. Microstructural and morphological characterizations of boride powders were carried out via scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. Moreover, atomic absorption spectroscopy (AAS) and differential scanning calorimetry (DSC) experiments were carried out to monitor the purity of the powders at different stages of the process. After mechanical alloying of the powder batches comprising 50 pct stoichiometrically excess amount of B₂O₃ for 30 hours and leaching with a 7 M HCl solution, pure W₂B₅ powders with an average particle size of 226 nm and an average grain size of 55.3 nm were successfully synthesized.     

Control input separation by actuation mode expansion for flow control problems

A control input separation method is proposed for reduced-order modelling in boundary control problems. The dynamics of flow systems are typically described by partial differential equations where the input affects the system through boundary conditions. From a control design perspective it is most desirable and natural to employ finite-dimensional representations in which the input enters the dynamics directly. The method proposed here to resolve the input from the boundary conditions is based on obtaining a proper orthogonal decomposition of the unforced flow of the system, and then augmenting this decomposition by optimally computed actuation modes, built using snapshots of the actuated flow. A reduced-order Galerkin model is then derived for this expansion, in which the input appears as an explicit term in the system dynamics. The model reduces exactly to the original baseline case under zero input conditions. The proposed method is then compared to an existing input separation technique, namely the sub-domain separation method. A boundary control example regarding the 2D incompressible Navier–Stokes equation is considered to illustrate the proposed method, where a controller is designed to achieve tracking of a desired 2D spatial profile for the flow velocity.     

Optimization of specific energy consumption for Bomaplex Red CR-L dye removal from aqueous solution by electrocoagulation using Taguchi-neural method

In this investigation, firstly, Taguchi method was applied to determine the optimum specific energy consumption (SEC) for dye removal from aqueous solution by electrocoagulation using aluminum electrodes. An orthogonal array (OA₁₆) experimental design that allows to investigate the simultaneous variations of five parameters (Initial dye concentration, Initial pH of the solution, Supporting electrolyte concentration, Supporting electrolyte type and Current density) having four levels was employed to evaluate the effects of experimental parameters with two replicates. According to Taguchi-neural method, while the optimum conditions that dye removal efficiency equals to 62.71 % were found to be initial dye concentration 600 mg/L, initial pH of the solution 6, supporting electrolyte concentration 7.0 mM, supporting electrolyte type NaCl, and current density 0.10 mA/cm². Under these optimum conditions, energy consumption is 0.38 kW h/m³. Alternatively, it can be said that optimum conditions can be modified as follows supporting electrolyte concentration of 10.0 mM and supporting electrolyte type CaCl₂, for 600 mg/L, initial dye concentration initial pH of the solution 6, and current density 0.10 mA/cm². Under these optimum conditions, SEC and dye removal efficiency are 0.45 kW h/m³ and 69.18 %, respectively.     

Capacitive micromachined ultrasonic transducer: transmission performance evaluation under different driving parameters and membrane stress for underwater imaging applications

Transmission performance of a CMUT element in terms of output pressure and displacements was evaluated. A SIMULINK model of single CMUT element based on mechanical model of MEMS capacitor was used and the analyses were performed under different ac and dc conditions. 2.6 µm thick Si, Poly-Si and Si₃Ni₄ membranes with a radius 60 µm were used to obtain results for underwater imaging application. Relation between membrane stress and outputs of CMUT was also investigated using SIMULINK model for commonly used CMUT membrane made of Si₃Ni₄ and polysilicon membrane under different electrical driving parameters. It was observed that different ac signal inputs (sine, square and sawtooth) showed different effects on CMUTs pressure and displacement characteristics. Our results indicated that the maximum output pressure and displacement were obtained in a square waveform. In addition, although stress on membrane increases the displacement and pressure of CMUT membrane made of Poly-Si, quality factor inversely proportional to stress on membrane. Membrane stress has adverse effect on Si₃Ni₄ membrane transmission outputs. The used model in this study might enable to determine optimum driving electrical inputs and stress on membrane to control CMUT outputs in terms of output pressure, displacement, quality factor and bandwitdh.

     

Memory Partitioning in the Limit

International Journal of Parallel Programming - The key difficulties in designing memory hierarchies for future computing systems with extreme scale parallelism include (1) overcoming the design...