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木质素;解聚;Ni基催化剂;均相催化剂;芳香化合物The depolymerization of lignin over different acid/base homogeneous catalysts and Ni/C was studied.The effects of Lewis acid and base on the influence of lignin conversion and aromatics yield were investigated.The result showed that the yield of aromatics from lignin was higher when NaOH and Ni/MLG（nickel/multilayer graphite） as catalysts than others.Moreover, the yield of phenols and guaiacols increased when Lewis acid and Ni/MLG as catalysts.And the yield of phenyl alcohols and arenes increased when alkali and Ni/MLG as catalysts.This article will provide a reference for the research of high-value utilization of lignin. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The main methods for the treatment of humeral shaft fractures are conservative treatment, open reduction and internal fixation, percutaneous minimally invasive plate internal fixation and intramedullary nail fixation, but the best treatment is still unclear. The network meta-analysis was used to compare the efficacy of conservative treatment, open reduction and internal fixation, percutaneous minimally invasive plate internal fixation and intramedullary nail fixation in the treatment of humeral shaft fractures. METHODS: A randomized controlled study on the treatment of humeral shaft fractures was searched in CNKI, Wangfang, VIP, Chinese BioMedical Literature Database, PubMed, EMbase, The Cochrane library and Web of Science. The search period was from inception to January 2021. The “bias risk assessment” tool recommended by Cochrane Collaboration Network was used to evaluate the quality of the literature. The RevMan 5.4 software and Stata 15.0 software were used to draw the graph and analyze the data of the network Meta. RESULTS: (1) A total of 23 randomized controlled trials were included. A total of 1 220 patients with humeral shaft fractures were divided into experimental group and control group. The control group was treated conservatively, and the experimental group was treated with open reduction and internal fixation, percutaneous minimally invasive plate internal fixation and intramedullary nail fixation. (2) Literature quality evaluation was included: 5 articles were of high quality and the other 18 were of low quality. (3) In terms of DASH score, the order of network Meta was as follows: open reduction and internal fixation > conservative > percutaneous minimally invasive plate internal fixation > intramedullary nail fixation. In terms of CMS score, the order of network Meta was as follows: open reduction and internal fixation > percutaneous minimally invasive plate internal fixation > conservative > intramedullary nail fixation. In terms of bone nonunion, the order of network Meta was as follows: percutaneous minimally invasive plate internal fixation > open reduction internal fixation > intramedullary nail fixation > conservative treatment. In terms of fracture healing time, the order of network Meta was as follows: percutaneous minimally invasive plate internal fixation > intramedullary nail fixation > open reduction and internal fixation > conservative. The network Meta order of iatrogenic radial nerve injury was conservative > percutaneous minimally invasive plate fixation > intramedullary nail fixation > open reduction and internal fixation. The order of total complications of network Meta was conservative > percutaneous minimally invasive plate internal fixation > open reduction and internal fixation > intramedullary nail fixation. CONCLUSION: A comprehensive analysis of the results of the network meta-analysis of the four intervention measures showed that the upper limb function DASH score and shoulder CMS score of the affected limb after open reduction and internal fixation were the best, but the incidence of complications was relatively high. More high-quality randomized controlled trials are needed to ensure the reliability of the results. [ABSTRACT FROM AUTHOR]

In order to solve the pollution problem of oily wastewater to the environment. 3-butanol was used as initiator, ethyleneoxide CEO), propylene oxide (PO) and methacryloxyethyl trimethylammonium chloride (DMC) were used as main raw materials. The intermediate polyether demulsifier ( PEO-PPO-PEO) was successfully synthesized under high temperature and high pressure. The demulsifying flocculant (PEO-PPO-PEO-PDMC) was synthesized by block polymerization of the intermediate and DMC. The structure was characterized by FTIR, SEM, chemical titration and particle size analysis, and the oil-water separation test was carried out. The results showed that the molecular weight of polyether demulsifier is 2 922, which has demulsification function. The RSN of demulsifying flocculant is 12. 8, which has good hydrophilicity. With the increase of demulsifying flocculant concentration, cloud point decreased gradually. Finally, through the demulsification flocculation experiment, it is concluded that the demulsification flocculant can achieve good oil-water separation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Aseptic loosening of the femoral prosthesis is one of the important issues affecting the life of knee joint replacement. Particles from tibial polyethylene component wear and stress shielding are the main causes of this loosening, which are all related to the femoral prosthesis materials. OBJECTIVE: To study the effects of femoral prosthesis materials on the stress of the distal femur of the knee joint and the contact pressure on the polyethylene component by finite element method. METHODS: Knee arthroplasty models with four materials, titanium alloy, cobalt-chromium alloy, titanium-hydroxyapatite functional gradient biomaterial (FGBM I), titanium-bioactive glass functional gradient biomaterial (FGBM II), were established; the prosthesis was endowed with different material properties in the Abaqus finite element software. The stress distribution of the important vulnerable path in the femur and the changes of contact pressure on the polyethylene component under different materials were studied. RESULTS AND CONCLUSION: (1) Compared with the currently used titanium alloy and cobalt-chromium alloy, functional gradient biomaterials could significantly increase the stress at the femoral-prosthetic interface and the stress in the pathway of an important vulnerable region of the femur. In those materials, FGBM I increased most significantly. (2) Maximum stress of FGBM I and FGBM II prostheses on polyethylene insert was 20.41% and 19.98% lower than cobalt-chromium alloy, 20.07% and 19.63% lower than titanium alloy. (3) The results showed that functionally gradient biomaterials could produce higher stress at the distal end of the femur and lower contact pressure on the polyethylene insert, reducing the wear and stress shield on polyethylene insert, and FGBM I has significant effects. [ABSTRACT FROM AUTHOR]

BACKGROUND: There is no uniform standard for acromioclavicular dislocation. Clavicular hook plate fixation is a commonly used fixation method clinically, but minimally invasive ligament reconstruction technology and arthroscopic surgery have become a research hotspot. OBJECTIVE: To observe the application value of suture bridge with thread anchor under arthroscopy in the treatment of acromioclavicular dislocation. METHODS: Patients with Tossy type III acromioclavicular dislocation who were admitted to Department of Orthopedic Surgery of General Hospital of Jizhong Energy Xingtai Mining Group between January 2016 and April 2018 were selected as the subjects. The patients were randomly divided into two groups. The patients in the arthroscopy group were treated with arthroscopic suture bridge technique with suture anchor for reduction and fixation, while those in the clavicle hook plate group were treated with clavicular hook plate for internal fixation. The length of surgical incision, duration of surgery, hospitalization time and time to return to work of both groups were recorded. The shoulder function was evaluated according to the Lazzcano criterion of curative effect at 3, 6 and 12 months after surgery. The visual analogue scale score of shoulder pain, abduction and raising, forward bend and raising were compared between the two groups. All patients were followed up for 1 year to record the occurrence of complications. This study was approved by the Medical Ethics Committee of General Hospital of Jizhong Energy Xingtai Mining Group. All subjects signed the informed consent. RESULTS AND CONCLUSION: (1) There was no significant difference in the duration of surgery between the two groups (P > 0.05). The surgical incision, hospitalization time and time to return to work of the arthroscopy group were significantly better than those of the clavicle hook plate group (P < 0.01). (2) According to the Lazzcano criterion of curative effect, the excellent and good rate of curative effect in the arthroscopy group (84%) was significantly better than that in the clavicle hook plate group (66%) at 3 months after surgery (P < 0.05). The excellent and good rates of curative effect in the arthroscopy group at 6 and 12 months after surgery were higher than those in the clavicle hook plate group (P > 0.05). (3) Visual analogue scale scores of the two groups showed a decreasing trend at 3, 6 and 12 months after surgery (P < 0.01). The visual analogue scale score of arthroscopy group was significantly lower than that of the clavicle hook plate group at the same time point (P < 0.01). (4) Angles of abduction and raising, forward bend and raising of both groups showed an increasing trend at 3, 6 and 12 months after surgery (P < 0.01). The angles of abduction and raising, forward bend and raising of the arthroscopy group were larger than those of the clavicle hook plate group at the same time point (P < 0.01). (5) The 1-year follow-up results showed that the incidence of complications in the arthroscopy group (6%) was significantly lower than that in the clavicle hook plate group (63%) (P < 0.01). (6) Compared with clavicular hook plate fixation, the technique of suture anchors under arthroscopy has the advantages of small trauma, quick recovery, fewer complications and no need to remove endografts again. Meanwhile, the surgery can also clearly diagnose the concomitant lesions in the joints and treat them when necessary, so as to improve the treatment effect. [ABSTRACT FROM AUTHOR]

Taking the crane vessel Sanhang Gong 5 as an example, combined with the environmental conditions of a certain nearshore wind farm, the technical problems involved in the construction and the whole process of the on-bottom setting of the crane vessel without relevant classification symbols were analyzed. The anchoring positioning and on-bottom stability were calculated. The wave current load was calculated by empirical formula and the wave force was calculated by using the frequency domain boundary element method. The calculation results show that under the condition of silt bottom material, the Sanhang Gong 5 needs to dive or float under the condition of velocity of flow less than 1.3 m/s to avoid anchor moving, in order to satisfy the on-bottom stability requirements, the initial amount of ballast water extra should be4500 t, and then reduced to 2500 t. [ABSTRACT FROM AUTHOR]

Objective To observe the clinical effect of Long's chiropractic technique combined with core strength training on patients with chronic non-specific low back pain (CNLBP). Methods A total of 120 CNBLP patients who received treatment from June 2015 to December 2017 were selected as the research objects. The patients were randomly divided into control group, Long's chiropractic group, core strength training group and joint training group, with 30 cases in each group. The control group only used conventional massage treatment. Long's chiropractic group was treated with Long's chiropractic technique on the basis of the control group. The core strength training group was treated with core strength training on the basis of the control group. On the basis of the control group, the combined training group used Long's chiropractic techniques and core muscle strength training for treatment. The visual analogue scale (VAS), Oswestry dysfunction index (ODI) and range of motion of each joint of the spine were evaluated before treatment and 1 month after treatment. Results After treatment, the four groups of VAS, ODI, flexion, extension, left and right flexion of the spine were significantly improved, and the differences were statistically significant (P <0.05). After treatment, the VAS and ODI of the Long's chiropractic group and the combined training group were significantly lower than those of the control group, and the differences were statistically significant (P <0.05). VAS and ODI in the combined training group were lower than those in the core strength training group, and the differences were statistically significant (P <0.05). There was no statistically significant difference in the flexion mobility between the groups after treatment (P >0.05). After treatment, post-extension range and right-side flexion range of the core strength training group and the joint training group were greater than those of the control group, and the differences were statistically significant (P <0.05). The joint training group's post-extension range and right-side flexion range were greater than those of the core strength training group and the Long's chiropractic group, and the differences were statistically significant (P <0.05). After treatment, the left flexion range of the core strength training group was greater than that of the Long's chiropractic group, and the difference was statistically significant (P <0.05). Conclusion Core strength training combined with Long's chiropractic therapy can further reduce the pain of CNLBP patients, improve their lumbar spine function, and enhance the range of motion of joint extension and left and right flexion. It is worthy of clinical promotion and application. [ABSTRACT FROM AUTHOR]

： The curves of average bond stress versus slip between reinforcing bars (rebar) with different reinforcement corrosion rates and recycled concrete were recorded during beam tests conducted in this research program. The influence of reinforcement corrosion rate on the bond-slip performance was analyzed. The results show that the splitting failure occurs when the rebar corrosion rate is zero and 1% while the pull-out failure occurs when the corrosion rate is 9%. Splitting and pull-out damages both occur when the corrosion rate is 3% and 6%. The bond strength rises first and then drops along the increase of the rebar corrosion rate. The bond stress reaches the maximum when the corrosion rate is 1%. The bond stress concentrates at the loading end when the corrosion rate is zero and 1%，and the bond stress spreads towards the free end with the increase of corrosion rate. The peak slip increases faster with the increase of the corrosion rate. On the basis of the test data，the position function showing the distribution of bond stress was fitted and the bond-slip constitutive equation was established. [ABSTRACT FROM AUTHOR]