[Comparison of 127° small and 135° large stem angle prostheses in total hip arthroplasty].

OBJECTIVE: To investigate the effect of total hip arthroplasty(THA) with the prosthesis of 127° small neck stem angle and 135° large neck stem angle. METHODS: From January 2014 to June 2016, 84 patients with THA were selected, including 44 males and 40 females, aged 45 to 72(53.4±8.1) years old, 68 patients with necrosis of the femoral head(32 on the left and 36 on the right), 16 patients with serious osteoarthritis of the hip caused by other reasons, and the course of disease was 9 to 36 (24.0±5.5) months. Forty-two patients in each group were evaluated by Harris score, visual analog score(VAS), length measurement of lower limbs, biomechanical evaluation of different angles of the neck stem. The complications and quality of life 24 months after operation were compared. RESULTS: Two patients in each group were lost, the rest were followed up for 30 to 36 (33.0±1.6)months. The Harris score and the length of both lower limbs were measured before and 1, 6, 12, 24 months after operation. The difference of Harris score and the length of both lower limbs in the two groups was significantly improved compared with that before operation(P<0.05), but there was no significant difference between the two groups(P>0.05). There was no significant difference between the two groups in VAS score before operation (P>0.05), but the VAS score of the group with large neck stem angle was significantly lower than that of the group with small neck stem angle(P<0.05). There was no significant difference in the incidence of postoperative complications between the two groups (P>0.05). The quality of life of the patients in the two groups after 24 months was significantly higher than that before operation (P<0.05). CONCLUSION: THA with large and small neck stem angle prosthesis can better recover the function of hip joint, but large neck stem angle can reduce the degree of postoperative pain and improve the quality of life of patients.

Rice straw pretreatment using deep eutectic solvents with different constituents molar ratios: Biomass fractionation, polysaccharides enzymatic digestion and solvent reuse.

Lignocellulosic biomass pretreatment with deep eutectic solvents (DESs) is a promising and challenging process for production of biofuels and valuable platform chemicals. In this work, rice straw was mainly fractionated into carbohydrate-rich materials (CRMs) and lignin-rich materials (LRMs) by 90% lactic acid/choline chloride (LC)-water solution with different molar ratio of hydrogen bond donor (HBD, lactic acid) and hydrogen bond acceptor (HBA, choline chloride). It was found that high HBD/HBA molar ratio of DESs was favorable for achieving CRMs and LRMs with high purity, and both HBD and HBA were responsible for effective biomass fractionation possibly due to their synergistic effect on highly efficient breakage of the linkage between hemicellulose and lignin and thus lignin extraction. About 30%-35% of lignin in native rice straw was fractionated as LRMs, and exceeding 70% of xylan were removed and fractionated into the liquid stream as forms of xylose, furfural and humins after pretreatment using aqueous LC (3:1, 5:1) solution. Consequently, polysaccharides enzymatic hydrolysis of the CRMs were significantly enhanced. Moreover, all the DESs could be recovered with high yields of around 90%, and 69% of the LC (3:1) was recovered after 5 cycles reuse at 90 °C. Besides, the recycled DES maintained a good pretreatment ability, and glucose yields of 60-70% were achieved in the enzymatic hydrolysis of CRMs obtained in each cycle. The facile process established in present work is promising for large scale production of fermentable sugars and other chemicals.

[Determination of several substrate-decomposition enzyme activities of Agrocybe cylindracea at different stages of development with spectrophotometer].

In the present paper the authors studied the activities of amylase, peroxidase, laccase, protease and cellulase at different developmental stages of agrocybe cylindracea and its mutation with the spectrophotometer. The result showed that the activity of amylase and peroxidase in hyphal stage is the highest for the two basidiomycetes. It can be concluded that these two enzymes are important in vegetative growth stage, but they may have little effect after the appearance of fruit body. The change of their protease is similar: in the hyphal growth stage it is higher than that of mature mushroom. But the activities of laccase and cellulase are very different between the two basidiomycetes. It is obvious that they are some different in physiology and biochemistry.