Background: Immobilization is an approach in industry to improve stability and reusability of urease. The efficiency of this technique depends on the type of membrane and the method of stabilization. Methods: The PEI-modified egg shell membrane was used to immobilize urease by absorption and glutaraldehyde cross-linking methods. The membranes were characterized by FTIR and AFM, and Nessler method was applied to measure the kinetic of the immobilized enzymes. Finally, the storage stability (6 ° C for 21 days) and reusability (until enzyme activity reached to zero) of the immobilized enzymes were investigated. Results: Based on FTIR, three new peaks were observed in both the absorption-(at 1389. 7, 1230. 8, and 1074. 2 cm-1 ) and the cross-linking (at -1 1615-1690, 1392. 7, 1450 cm ) immobilized enzymes. The surface roughness of the native membrane was altered after PEI treatment and enzyme immobilization. The optimal pH of cross-linking immobilized enzymes was shifted to a more neutral pH, while it was alkaline in adsorptionimmobilized and free enzymes. The reaction time decreased in all immobilized enzymes (100 min for free enzyme vs. 60 and 30 min after immobilizing by adsorption and cross-linking methods, respectively). The optimal temperature for all enzymes was 70 ° C and they had a higher Km and a lower Vmax than free enzyme. The stability and reusability of urease were improved by both methods. Conclusion: Our findings propose these approaches as promising ways to enhance the urease efficiency for its applications in industries and medicines.

A 32-year-old man with graft loss due to chronic rejection received a 2nd kidney allograft from a living donor in the left iliac fossa, while the 1st was left in the contralateral side. An episode of acute rejection occurred at 1 month, resolved by steroid therapy.

Objective: This study evaluated the effect of incorporating 1 wt% egg shell powder (ESP) into Biodentine™ (BD) on its physicomechanical properties. Methods: Chicken eggs were ground and sterilized. Then, one wt% ESP was added to BD powder and mixed with BD liquid. The mixture’s pH and solubility were measured on 1, 3, 7, and 28 days. The setting time was determined using a Gillmore needle. Compressive strength was measured using a universal testing machine after 1 and 14 days. Surface chemistry was analyzed via FTIR spectroscopy. The findings were compared by independent samples t-test, the repeated measures ANOVA, and the Bonferroni post-hoc test (α = 0.05). Results: pH levels were comparable between the groups (P > 0.05). BD-ESP had a higher setting time than BD (P < 0.001). BD-ESP solubility was significantly higher than BD on day 1 (P = 0.001) but lower on days 7 (P = 0.006) and 28 (P = 0.001). On day 1, BD had higher compressive strength than BD-ESP (P = 0.027), whereas the compressive strength of both groups was comparable on day 14 (P = 0.099). FTIR analysis revealed an additional IR band associated with the phosphate band in the BD-ESP group, suggesting new apatite formation. Conclusions: Incorporating 1% ESP into BD resulted in lower initial solubility but higher solubility after a week and a month, likely due to increased ion dissolution. ESP incorporation also promoted additional apatite formation but negatively impacted the setting time and initial strength of BD.

In the present research, egg-shell Pd-Ag/a-Al2O3 catalysts prepared by impregnation method using self-improved spherical alumina support with BET 13.34m2/g and pore volume 0.36cm3/g were used for the hydrogenation of acetylene in the presence of a large excess of ethylene (tail-end cuts) and their activity-selectivity patterns were compared with the commercial one. All of the synthesized catalysts were tested under 60C, 10bar, space velocity 6500h-1 and H2/C2H2 ratio 1.5 (mol/mol) which is the same as an industrial plant.The effect of impregnation operating parameters, such as pH of the impregnation solution and impregnation type, on palladium penetration depth and palladium uptake was investigated.pH 1.5 is best for impregnation solution. Catalytic performance tests showed that for Pd-Ag/a-Al2O3 catalysts, sequential impregnation was a suitable method for the active metal. By controlling the synthesis condition, the best Pd-Ag/a-Al2O3 sample was an egg-shell one in which Pd was loaded evenly in a layer with thickness 20-30µm. This sample gave ethylene selectivity of 100% and acetylene conversion of 58% which is higher than the commercial one.