Objective To evaluate the feasibility of low tube voltage (80 kV)with low concentration contrast medium iodixanol (270 mg I/mL)in cerebral perfusion using 640-slice volume CT.Methods Patients who underwent CT cerebral perfusion were randomly divided into two groups.Group A:100 kV,320 mg I/mL contrast medium;group B:80 kV,270 mg I/mL contrast medium.The effective dose(ED)was record,the frontal cortex,temporal cortex and occipital cortex were selected as regions of interest(ROI),and the cerebral perfusion parameters (rCBV,rCBF,MTT,TTP)were measured separately.The CT value of the M1 segment of cerebral middle artery, the C7 segment of internal carotid artery,the basilar artery and the surrounding brain tissue were measured.The signal-to-noise radio (SNR)and the contrast-to-noise ratio(CNR)of two groups were compared and analyzed.All data will be statistically analyzed,and the consistency of two physicians for image quality evaluation was analyzed by Kappa analysis.Results The ED of group B was 4.56 mSv, which was reduced by 35.2% compared to group A(7.04 mSv).The perfusion parameters,the CT value of ROI and the SNR,CNR for two groups were of no statistical difference(P>0.05).Conclusion The feasibility of low tube voltage combined with low concentration contrast media is better,which not only meets the requirements of clinical diagnosis,but also reduces the radiation dose and the probability of contrast induced nephropathy.

Glycoside compounds are widely used in medicine, food, surfactant, and cosmetics. The glycosidase-catalyzed synthesis of glycoside can be operated at mild reaction conditions with low material cost. The glycosidase-catalyzed processes include reverse hydrolysis and transglycosylation, appropriately reducing the water activity in both processes may effectively improve the catalytic efficiency of glucosidase. However, glucosidase is prone to be deactivated at low water activity. Thus, glucosidase was immobilized to maintain its activity in the low water activity environment, and even in neat organic solvent system. This article summarizes the advances in glycosidase immobilization in the past 30 years, including single or comprehensive immobilization techniques, and immobilization techniques combined with genetic engineering, with the aim to provide a reference for the synthesis of glycosides using immobilized glycosidases.
Catalysis ; Enzymes, Immobilized ; Glycoside Hydrolases/genetics* ; Glycosides/biosynthesis* ; Hydrolysis

Objective To analyze the distribution of common allergens in children with allergic rhinitis(AR)in Hangzhou,and to provide reference for its prevention and treatment.Methods From January 2020 to December 2022,13 521 children who were diagnosed with AR and underwent in vitro serum specific immunoglobulin E(sIgE)detection in Affiliated Hangzhou First People's Hospital,School of Medicine,Westlake University were selected as the research objects.The positive rates of allergens in children with AR of different genders,ages and seasons were compared.Results Among 13 521 children,the positive rate of sIgE was 54.49%(7367/13 521),of which 64.82%were allergic to only one allergen.Among the 19 common allergens,the top three overall positive rates were household dust mite(44.27%),milk(14.62%),and mixed grass(4.82%).The positive rates of allergens of house dust mites,cat hair dander,mulberry,mold combination,tree pollen combination,amaranth,cockroach,milk,shrimp,crab,pineapple,shellfish and mango in male children were significantly higher than those in female children(P<0.05).The positive rates of allergens of house dust mite,mixed grass,cat hair dander,mulberry,mold combination,egg white,shrimp,crab,pineapple,cashew nuts and shellfish in different age groups were statistically significant(P<0.05).July and August were the two months with the highest allergen positive rate.The allergen positive rates of house dust mite,dog and cat hair dander were the highest in summer,and the allergen positive rate of plants was consistent with the flowering season.The sIgE concentration of house dust mite(77.87%)was mainly grade 3 and above.The sIgE concentration of other allergens was mainly grade 1 and 2.Conclusion Dust mites and milk are the most common allergens in children with AR in Hangzhou,and the distribution of allergens varies with gender,age and season.Allergen detection can provide a more accurate plan for the diagnosis,prevention and treatment of AR.