Objective To investigate the correlation between mechanical properties and hemostatic ability of the sealing hydrogels. Methods The gelation time, elastic modulus, viscous modulus, bursting strength and hemostatic ability of the hyaluronic acid/gelatin hydrogels were measured. Compared with fibrin sealant, gelation time and mechanical parameters were proposed to judge the feasibility of sealing hydrogels to be used for hemostasis in clinic. Results Hydrogels with a long gelation time, low elastic modulus, low viscous modulus and small bursting strength were merely suitable for hemostasis in minor bleeding. The hydrogels with short gelation time, high elastic and viscous modulus and large bursting strength could effectively reduce the blood loss in the cases of massive bleeding. Conclusions The hemostatic ability of a hydrogel was correlated to its gelation time, elastic modulus, viscous modulus and bursting strength. To achieve hemostasis as effective as fibrin sealant, the gelation time of a sealing hydrogel should be less than 120 s, its elastic and viscous modulus should exceed 600 Pa and 120 Pa, respectively. For the damage with diameter of 2 mm in the tissue model, the burst strength should exceed 10.7 kPa and preferably be larger than 16.0 kPa.

Objective:To analyze and compare VP1 and VP4 genetic characteristics of human enterovirus 71(EV71) isolated from children with severe and mild hand-foot and mouth disease(HFMD).Methods:EV71 strains isolated from severe HFMD patients (6 cases) and mild HFMD patients (6 cases) in Taizhou district, Zhejiang province were included during 2016.Total virus RNA was extracted by Viral RNA Mini Extraction Kit, and reverse transcription polymerase chain reaction(RT-PCR) was used to amplify the sequence of the VP1 and VP4 genes of EV71.And then the sequencing results were compared with those of A, B, C genotype reference EV71 strains from GenBank by nucleotide alignment and amino acid alignment analysis.Results:There were no statistically significant differences in sex and age between the two groups(χ 2=14.51, t=2.82, all P<0.05). The homogeneity between EV71 strains from severe patients and mild patients was 95.8%~99.6% and 99.1%~100.0% for VP1 nucleotide sequences and amino acid sequences, respectively, while 95.0%~99.9% and 99.0%~100.0% for VP4 nucleotide sequences and amino acid sequences, respectively.The twelve EV71 strains isolated from HFMD patients in Taizhou shared the highest identity with EV71-genotype C, especially genotype C4a.In addition, compared with the mild patients, three respective strains from severe HFMD patients showed mutations at the residue 170 in the VP1 protein(V→L), residue 293 in the VP1 protein(A→S) and residue 7 in the VP4 protein(T→A). Conclusion:All EV71 strains isolated from severe and mild HFMD patients in Taizhou district share high homology of nucleotide and amino sequence, and all of them belong to subgenogroup C4a.The mutations in the VP1 and VP4 of EV71 might be related to HFMD disease severity.