Small-diameter vascular grafts of Bombyx mori silk fibroin prepared by a combination of electrospinning and sponge coating

The present study aimed to produce small-diameter grafts made of a silk fibroin by electrospinning. In order to reinforce the electrospun silk fibroin graft (ES), the graft was coated with a silk sponge (ESSC). Physical properties such as a diameter of the electrospun silk fibers were influenced by a concentration of fibroin solution. Ultimate tensile strength (UTS) of the ESSC graft was improved compared to the ES graft. However, the ESSC graft was less compliant than the ES graft. Importantly, water permeability of the ESSC graft was within the range of which endothelialization was promoted in previous studies.     

Controlled chemical precipitation of titania for membrane applications—effect of heat treatment and fabrication conditions on its performance

Controlled chemical precipitation method was used to obtain nanosized titania (TiO₂) powders. XRD, DTA/TGA/DTG techniques were employed for phase analysis and to know the thermal changes taking place in precipitated precursor during heating. The effect of processing and fabrication conditions viz. calcination temperature, mold pressure and sintering temperature/time on membranes prepared from this titania powder was studied using permeability measurements. The bulk porosity, average pore size and permeability were found to decrease with increase in the molding pressure. However, an increase in the sintering period increases the bubble point and brings the diameter of the larger pores nearer to that of the average pore.     

A new combustion route to γ-Fe2O3 synthesis

A new combustion route for the synthesis of γ-Fe ₂ O ₃ is reported by employing purified a-Fe ₂ O ₃ as a precursor in the present investigation. This synthesis which is similar to a self propagation combustion reaction, involves fewer steps, a shorter overall processing time, is a low energy reaction without the need of any explosives, and also the reaction is completed in a single step yielding magnetic iron oxide i.e. γ-Fe ₂ O ₃ .The as synthesized γ-Fe ₂ O ₃ is characterized employing thermal, XRD, SEM, magnetic hysteresis, and density measurements. The effect of ball-milling on magnetic properties is also presented.     

Characterization of Al Skeletal Structures Fabricated by Ultrasonic Powder Consolidation

Metallurgical and Materials Transactions A - Skeletal aluminum structures were fabricated by ultrasonic powder consolidation (UPC) of NaCl—15 mass pct Al and...     

Induction after administering paraquat of heme oxygenase-1 and heat shock protein 70 in the liver of senescence-accelerated mice

Age-associated changes in the induction of heme oxygenase (HO-1) and heat shock protein 70 (HSP70) after the administration of paraquat were investigated in the liver of senescence-accelerated mice (SAMs). The extent of HO-1 and HSP70 induced in response to paraquat decreased significantly with age, and the level of oxidized proteins increased with age. Moreover, the extent of induced HSP70 was lower in mice that were prone to accelerated senescence (SAMP1/(/)Fky) than in mice that were resistant to accelerated senescence (SAMR1/Fky) of the same age. These results suggest that an age-associated decline in the levels of HO-1 and HSP70 enhanced oxidative damage during the aging process. Age-dependent changes in HO-1 and in the levels of oxidized proteins were examined in SAMP1/(/)Fky. The accumulation of oxidized proteins was suppressed when HO-1 was induced, but increased markedly after the induction of HO-1 decreased. Free iron, the residuum from heme degradation, might mediate free radical production. The role of HO-1 is discussed in relation to the oxidative damage associated with age.     

Light and electron microscopic findings in rhinosporidiosis after dapsone therapy

Morphological findings in serial nasal mucosal biopsies from three cases of rhinosporidiosis on dapsone therapy were compared with biopsies from 33 patients taken before dapsone or surgical treatment was initiated. All biopsies were examined by light microscopy and five by electron microscopy. Counts of histologically intact and degenerated organisms showed a decreasing proportion of intact forms with treatment.     

Investigation of CTARA wood-burning stove. Part I. Experimental investigation

This paper describes experimental investigation of a single pot wood-burning stove developed atCtara. The stove incorporates features such as a converging combustion space, a grate, preheated secondary air and a swirling-device. Using chipped wood and a large diameter vessel (30 cm), efficiencies in excess of 40% have been measured. An electric stove, having a geometry similar to that of the woodburning stove, has also been experimented with to obtain magnitudes of heat transfer coefficient at the vessel bottom, to estimate relative contributions of convection and radiation heat transfer to the vessel bottom, to study the effect of flame to grate heat release ratios and to study the effect of depth of insertion of the vessel into the stove. Finally, a 3-pot mud stove used in the Konkan region is investigated and it is shown that provision of a grate improves the efficiency of the stove.     

Lung preservation with low-potassium dextran flush in a primate bilateral transplant model

We used a bilateral lung transplant model to confirm, in primates, the results of lung preservation studies previously obtained in a canine single-lung transplant model. The donor lungs were flushed with low-potassium dextran solution and maintained semiinflated with 100% oxygen at 10 degrees C for a planned ischemic time of 12 hours for the lung implanted first. Of eight experiments performed, results in the 6 operative survivors form the basis of this report. After bilateral lung transplantation, animals were maintained on a ventilator for 6 hours; arterial oxygen tension, pulmonary artery pressure, and pulmonary vascular resistance were determined in the recipients at 2, 4, and 6 hours after transplantation and compared with donor values, which served as controls. Arterial oxygen tension in the recipients did not differ from the controls (p = not significant), whereas the pulmonary artery pressure and pulmonary vascular resistance showed significant elevation (p < 0.05 versus control values). After the 6 hours of assessment, the animals were extubated and 3 survived for 48 to 72 hours with a mean arterial oxygen tension of 69 mm Hg on room air. These results demonstrate excellent lung function after a minimum of 12 hours of preservation in a primate model in which the animal is totally dependent on the function of transplanted lung tissue, and confirm the potential for prolonged clinical lung preservation.