BACKGROUND:Three-dimensional finite element simulation has been widely used in biomechanics. However, there is little research in knee joint replacement. The study of femoral prosthesis is less.
OBJECTIVE:To analyze the optimal positioning parameters of knee replacement and femoral prosthesis implantation, and to verify the efficacy of Gemini-PS knee prosthesis in total knee arthroplasty.
METHODS: (1) Knee finite element model in total knee replacement was constructed. Orthogonal experiment was performed in femoral osteotomy positioning parameters. The shift amount A, external rotation degree B, and valgus degree C of femoral prosthesis were selected as the relevant factors for orthogonal experiment. Three values were taken for each parameter to establish orthogonal tables. Nine experimental combined knee replacement finite element models were created and analyzed with finite element. Analysis of variance and range analysis were used by optimization. (2) Totally 42 patients (47 knees) with knee osteoarthritis received total knee arthroplasty with Gemini-PS knee joint prosthesis. Knee joint function was evaluated after replacement with Hospital for Special Surgery knee score and American Knee Society knee score. Knee pain was assessed with Visual Analogue Scale score.
RESULTS AND CONCLUSION:(1) Minimal polyethylene substrate surface compressive stress peak was translation 0 mm, external rotation of 3°, valgus 6°; the peak stress was 15.9 MPa. Among the influential factors, the effects of internal and external translation were larger than that of external rotation angle, and greater than that of valgus angle. The optimal positioning parameter combination was pan 0 mm, external rotation 3°, valgus 6° by range analysis and variance analysis. Orthogonal experiment was valid by simulation. (2) 42 patients were folowed up for 12-36 months. One patient affected subcutaneous fat liquefaction of the lower segment of the incision. Hospital for Special Surgery knee score and American Knee Society knee score were significantly higher after implantation (P < 0.05). Visual Analogue Scale score was significantly lower after replacement (P < 0.05). X-ray films showed that osteolysis, dislocation or loosening was not found. The recovery of knee joint was good after operation. (3) These findings

Objective To study the inhibition effect of non custodial terpenes-3β-alcohol to experimentally in-duced autoimmune encephalomyelitis in guinea pigs. Methods Different doses (25 mg/kg, 50 mg/kg and 100 mg/kg) of non custodial terpenes-3β-alcohol were given to the experimentally induced autoimmune encephalomyelitis model of guinea pigs by gavage for 8 weeks. Plasma levels of CD4+/CD8+, IL-1, IL-2, IL-6, IL-10, neuropeptide Y (NPY), beta endorphin (β-EP) , transforming growth factor-β(TGF-β), matrix metalloproteinase (MMP-2), nitric oxide synthase (NOS) and leuko-cyte differentiation antigen CD3 were assessed. The brain neuron morphology changes was observed under light microscopy while its ultrastructure changes was observed under electron microscope. NOS expression in neurons was observed through immunofluoresce technology. Results Non custodialterpenes-3β-alcohol inhibited the increase of plasma CD4+/CD8+, IL-1, IL-2, IL-6, IL-10, MMP-2, CD3 and NPY while decrease of plasmaβ-EP, brain TGF-β. It also increase NOS expres-sion in neuronal cytoplasm and maintained neuron morphology. Conclusion Non custodial terpenes-3β-alcohol inhibit-ed the experimental autoimmune encephalomyelitis in guinea pig.

Objective:To establish a composite functional evaluation system to study the clinical efficacy of single plate and double plate internal fixation in the treatment of C3 distal radius fractures in the elderly.Methods:62 elderly patients (≥ 60 years old) with type C3 distal radius fractures who were admitted to the First Affiliated Hospital of Anhui University of Science and Technology from September 2018 to August 2021 were retrospectively selected and divided into two groups according to the surgical methods: bilateral plate internal fixation treatment group (double plate group) and unilateral plate internal fixation treatment group (single plate group); The preoperative anatomical angle, wrist mobility (flexion and extension) and radius shortening of the two groups were recorded. The anatomical angle, wrist mobility (flexion and extension), clinical Gartland-Werley, DASH Score for Upper Limb Function (DASH) , Wrist Joint Cooney Score and clinical healing time at the 3rd, 6th, 9th and 12th months after operation were followed up. A composite evaluation table was established to comprehensively evaluate the postoperative recovery of patients in the two group.Results:There was no significant difference in anatomical indexes of radius between the two groups before operation (all P>0.05). All anatomical angles and wrist range of motion were within the normal range after operation, and there was no statistical difference between the two groups in each anatomical index of radius within 3 and 6 months after operation (all P>0.05). However, the palmar inclination, ulnar deviation, wrist flexion and dorsiflexion mobility of the double plate group were relatively stable at 9 and 12 months after operation, which were better than those of the single plate group (all P<0.05). The palmar inclination and ulnar deviation of the single plate group increased with time. After operation, the radius shortening of the two groups recovered significantly, and the radius length of the double plate group was maintained better than those of the single plate group for 9 and 12 months (all P<0.05). There was no significant difference in the scores of the two groups within 3 and 6 months after operation (all P>0.05), but the Gartland Werley score, DASH score and Cooney wrist score of the double plate group were significantly better than those of the single plate group at 9 and 12 months after operation (all P<0.05). The clinical healing time of single plate treatment was (14.51±0.88)weeks, the longest was 108 days, while that of double plate treatment was (12.03±1.77)weeks, the longest was 129 days, with statistically significant difference ( P<0.05). There was no significant difference in the incidence of complications between the two groups ( P>0.05). There was no statistically significant difference between the two groups in the final composite evaluation results ( P>0.05), but the total score of the double plate group was smaller than that of the single plate group, with a difference of 39.67 points, indicating that the double plate group still had certain advantages in various scores. Conclusions:According to the composite evaluation system, both single plate and double plate treatment of C3 distal radius fractures in the elderly can achieve satisfactory results. Double plate fixation of distal radius fractures still has a certain significance in maintaining joint stability and improving joint mobility.

Objective:To observe the effect of evidence-based early activity training on postoperative delirium in patients with brain tumor resection.Methods:This study used non-contemporary comparison method, a total of 238 patients admitted to the Second Affiliated Hospital of Zhejiang University School of Medicine in 2019, were included. 121 patients who met the inclusion criteria and signed informed consent after craniotomy during January 1st,2019 to June 31th,2019 were included in the control group, and 117 patients who met the criteria and obtained informed consent after craniotomy during July 1 to December 31,2019, were included in the experimental group. Neurosurgical postoperative routine nursing care were given to the control group. The experimental group received evidence-based early activity training. The incidence of delirium, duration of delirium, Barthel Index (BI), delirium-related adverse events and other indicators of postoperative hospitalization were compared between two groups.Results:The incidence of delirium, duration of delirium and postoperative hospital stay in the experimental group were 9.5%, 2.0 (1,3) days and 7 (5,10) days, lower than 23.3%, 3.0 (1,5) days and 8 (6,11) days in control group, and the differences were statistically significant ( χ2 value was 8.17, Z value were 2.96 and -2.01, P<0.05). BI index 1 week and 1 month after discharge in the experimental group was 90 (85, 90), 100 (100, 100), higher than the control group of 90 (86, 90) and 100 (100,100), with statistically significant difference ( Z values were -2.41 and -2.46, P<0.05), the comparison of adverse events, 0 case in experimental group, 1 case in control group, there was no statistically significant difference ( χ2 value was 0.97, P>0.05). Conclusions:Early evidence-based activities in patients with brain tumor resection can reduce the incidence of postoperative delirium, shorten the duration of postoperative delirium and postoperative hospital stay, and improve the ability of patients to take care of themselves after surgery, which is safe and effective.

Industrial enzymes have become the core "chip" for bio-manufacturing technology. Design and development of novel and efficient enzymes is the key to the development of industrial biotechnology. The scientific basis for the innovative design of industrial catalysts is an in-depth analysis of the structure-activity relationship between enzymes and substrates, as well as their regulatory mechanisms. With the development of bioinformatics and computational technology, the catalytic mechanism of the enzyme can be solved by various calculation methods. Subsequently, the specific regions of the structure can be rationally reconstructed to improve the catalytic performance, which will further promote the industrial application of the target enzyme. Computational simulation and rational design based on the analysis of the structure-activity relationship have become the crucial technology for the preparation of high-efficiency industrial enzymes. This review provides a brief introduction and discussion on various calculation methods and design strategies as well as future trends.
Biocatalysis ; Biotechnology ; Enzymes ; chemistry ; metabolism ; Metabolic Engineering ; Protein Engineering ; Structure-Activity Relationship

Objective:To explore the clinical efficacy of Masquelet technique combined with tissue flap transfer in the treatment of infectious composite bone and soft tissue defects in the early and middle stages after internal fixation for tibial fractures.Methods:From October 2017 to November 2020, 12 patients (13 tibial fractures) with infectious bone and soft tissue defects in the early and middle stages after internal fixation were treated in the Department of Orthopaedics, 988th Hospital of the Joint Logistics Support Force of CPLA by two-phased surgery with retaining internal fixation. Phase I procedures were thoroughly removal of the infected lesions and failed screws, preserving internal implants as many as possible, implantation of absorbable calcium sulphate and an antibiotics blended string of beads into the distal and proximal medullary cavity of the fractured bones, filling the bone defect and wrapping the internal implants with antibiotics loaded bone cement. The size of defects was 3.5 cm × 5.0 cm-7.5 cm × 14.5 cm, and the flaps for wound coverage sized 4.0 cm × 5.5 cm-8.0 cm × 15.0 cm. As for the repair of donor site, 8 limbs were sutured directly, 5 limbs could not be closed completely, and the remaining wounds were covered by skin grafting after suture. Based on well control of infection and stable clinical signs, fillings of bone cement were then removed in Phase II surgery, or 6-9 weeks after primary surgery. Autologous cancellous bone pieces or composite allogeneic bone were fully implanted around the induction membrane formed by Masquelet technique, and auxiliary steel plates were implanted for internal fixation of unstable fractures. After discharge, the patients visited the outpatient clinic regularly, and combined with Wechat follow-up. The texture, colour and bone healing were observed. At the last follow-up, the function of the affected limbs were assessed according to Johner-Wruhs evaluation standard.Results:After Phase I surgery, 13 flaps survived smoothly without vascular compromise. The wounds healed in Phase I. Two patients (2 sides) had recurrent infections. Re-debridement was performed and external fixation was applied after removal of internal fixation. After Phase II surgery, all patients were included in 12-26 months of follow-up, with an average of 18 months. Thirteen lower leg fractures healed well, and the time of bone healing was 16-25 (average 19.5) weeks. The Johner Wruhs criteria was used in evaluation of the function of affected limbs, and it was found that 6 patients were in excellent, 5 in good and 2 in fair.Conclusion:It is feasible while preserving the internal implants, to use membrane induction technique (Masquelet technique) combined with flap transfer, together with the absorbable calcium sulphate antibiotic sustained-release beads as a carrier in the phased treatment of infectious bone defects and bone exposure in the early and middle stages after the surgery of tibial internal fixation. It also gives a higher rate of excellence in surgical outcome. This study explores a treatment procedure for traumatic bone infection combined with composite soft tissue defects.

Central nervous system (CNS) injuries, including stroke, traumatic brain injury, and spinal cord injury, are leading causes of long-term disability. It is estimated that more than half of the survivors of severe unilateral injury are unable to use the denervated limb. Previous studies have focused on neuroprotective interventions in the affected hemisphere to limit brain lesions and neurorepair measures to promote recovery. However, the ability to increase plasticity in the injured brain is restricted and difficult to improve. Therefore, over several decades, researchers have been prompted to enhance the compensation by the unaffected hemisphere. Animal experiments have revealed that regrowth of ipsilateral descending fibers from the unaffected hemisphere to denervated motor neurons plays a significant role in the restoration of motor function. In addition, several clinical treatments have been designed to restore ipsilateral motor control, including brain stimulation, nerve transfer surgery, and brain-computer interface systems. Here, we comprehensively review the neural mechanisms as well as translational applications of ipsilateral motor control upon rehabilitation after CNS injuries.
Animals ; Spinal Cord Injuries/therapy* ; Motor Neurons/physiology* ; Brain ; Stroke ; Recovery of Function/physiology*