Validation of fluid bed granulation utilizing artificial neural network

Three innovative components (an annular gap spray system, a booster bottom and an outlet filter) have been developed by Innojet Technologies to improve fluid bed technology and to reduce the common interference factors (clogging of nozzles and outlet filters, spray loss, spray drying and fluidized bed heterogeneity). In a fluid bed granulator, three conventional components have been replaced with these innovative components. Validation of the modified fluid bed granulator has been conducted using a generalized regression neural network (GRNN). Under different operating conditions (by variation of inlet air temperature, liquid-binder spray rate, atomizing air pressure, air velocity, amount and concentration of binder solution and batch size), sucrose was granulated and the properties of size, size distribution, flow rate, repose angle and bulk and tapped volumes of granules were measured. To confirm the method's validity, the trained network has been used to predict new granulation parameters as well as granule properties. These forecasts were then compared with the corresponding experimental results. Good correlation has been obtained between the predicted and the experimental data. From these findings, we conclude that the GRNN may serve as a reliable method to validate the modified fluid bed apparatus.     

Pruritic urticarial papules and plaques of pregnancy: current status

Pruritic urticarial papules and plaques of pregnancy is a common benign dermatosis of pregnancy that was described in 1979 as an intensely pruritic urticarial cutaneous eruption. This is a well-defined clinical entity that mainly occurs in primigravidas in the third trimester, which resolves spontaneously or with delivery and is usually responsive to topical treatments. The aetiology of PUPPP is obscure. Histology is non-specific, but consistently shows mild lymphohistiocytic perivascular inflammatory infiltrate with a variable number of eosinophils. Immunofluorescent studies are negative. The maternal and fetal prognosis are generally unaffected, and the condition is usually responsive to topical corticosteroids and oral antihistamines.     

Characterizing tourniquet induced hemodynamics during total knee arthroplasty using diffuse optical spectroscopy

Tourniquet use creates a reduced blood surgical field during total knee arthroplasty (TKA), however, prolonged ischemia may cause postoperative tourniquet complications. To understand the effects of tourniquet-induced ischemia, we performed a prospective observational study using quantitative broadband diffuse optical spectroscopy (DOS) to measure tissue hemodynamics and water and lipid concentrations before, during, and after tourniquet placement in subjects undergoing TKA. Data was collected for 6 months and, of the total subjects analyzed (n = 24), 22 were primary TKAs and 2 were revision TKA cases. We specifically investigated tourniquet-induced hemodynamics based upon subject-specific tissue composition and observed a significant relationship between the linear rate of deoxygenation after tourniquet inflation and water/lipid ratio (W/L, p < 0.0001) and baseline somatic tissue oxygen saturation, StO₂ (p = 0.05). Subjects with a low W/L ratio exhibited a lower tissue metabolic rate of oxygen consumption, (tMRO₂) (p = 0.008). Changes in deoxyhemoglobin [HbR] (p = 0.009) and lipid fraction (p = 0.001) were significantly different between high and low W/L subject groups during deoxygenation. No significant differences were observed for hemodynamics during reperfusion and total tourniquet time was neither significantly related to the hemodynamic hyperemic response (p = 0.73) nor the time to max StO₂ after tourniquet release (p = 0.57). In conclusion, we demonstrate that DOS is capable of real-time monitoring of tissue hemodynamics distal to the tourniquet during TKA, and that tissue composition should be considered. DOS may help surgeons stratify hemodynamics based upon tissue composition and eventually aid the preoperative risk assessment of vascular occlusions from tourniquet use during TKA.