As the chip of synthetic biology, enzymes play a vital role in the bio-manufacturing industry. The development of diverse functional enzymes can provide a rich toolbox for the development of synthetic biology. This article reports the construction of an artificial enzyme with the introduction of a non-natural cofactor. By introducing the 4-dimethylaminopyridine (DMAP) cofactor into the optimal protein skeleton via covalent bonds based on a click-chemistry strategy, we successfully constructed a novel artificial enzyme with the DMAP cofactor as the catalytic center. The artificial enzyme successfully catalyzed an unnatural asymmetric Morita-Baylis- Hillman (MBH) reaction between cycloketenone and p-nitrobenzaldehyde, with a conversion rate of 90% and enantioselectivity (e.e.) of 38%. This study not only provides an effective strategy for the design of new artificial enzymes but also establishes a theoretical basis for the development of unnatural biocatalytic MBH reactions.
Biocatalysis ; 4-Aminopyridine/chemistry* ; Enzymes/metabolism* ; Coenzymes/chemistry* ; Benzaldehydes/chemistry* ; Protein Engineering/methods* ; Click Chemistry

Objective:To investigate the efficacy of single locked-plate internal fixation combined with autologous iliac bone graft in the treatment of Rorabeck type II periprosthetic distal femural fracture (PDFF) after total knee arthroplasty (TKA).Methods:A retrospective case series study was made on 13 patients suffering from Rorabeck type II PDFF after primary TKA together with severe osteoporosis (T value≤ -2.5 SD) admitted to 940th Hospital of Joint Logistics Support Force of PLA from January 2016 to December 2020, including 4 males and 9 females, aged 65-85 years [(75.2±6.5)years]. All patients were treated with single locked-plate internal fixation combined with autologous iliac bone graft. Anti-osteoporosis and early standardized joint function rehabilitation were undertaken postoperatively. The operation time and intraoperative blood loss were recorded. The range of motion of knee joint was compared before operation, at postoperative 3, 6 and 12 months and at the last follow-up. The Hospital for Special Surgery (HSS) knee score was assessed at postoperative 3, 6 and 12 months and at the last follow-up to evaluate the recovery of knee joint function. The bone mineral density was reexamined at postoperative 6 months and 12 months to evaluate the therapeutic effect of anti-osteoporosis. Complications were detected as well.Results:All patients were followed up for 12-72 months [(43.2±19.9)months]. The operation time was 90-135 minutes [(103.8±12.6)minutes], with the intraoperative blood loss of 100-250 ml [(150.0±45.6)ml]. The range of motion of knee joint was (114.6±7.8)°, (90.4±8.0)°, (97.3±4.8)° and (98.1±6.3)° before operation and at postoperative 3, 6 and 12 months (all P<0.05). The HSS knee score was (80.2±2.2)points, (84.6±2.9)points and (87.3±3.3)points at postoperative 3, 6 and 12 months (all P<0.05). The knee joint function was excellent in 10 patients and good in 3 at postoperative12 months, and the excellent and good rate was 100%. The T value of bone mineral density was (-3.8±0.6)SD, (-3.4±0.6)SD and (-2.9±0.6)SD preoperatively and at postoperative 6 months and 12 months (all P<0.05). One patient experienced nonunion and was cured after secondary autologous iliac bone grafting combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) bone grafting. Three patients developed venous thrombosis of lower limbs and were cured with oral administration of rivaroxaban. One patient had mild knee flexion and extension limitation and was improved after manual release under femoral nerve block anesthesia and subsequent functional rehabilitation. Conclusion:For patients with Rorabeck type II PDFF after TKA, single locked-plate internal fixation combined with autologous iliac bone graft has advantages of short operation time, few intraoperative bleeding, satisfactory knee range of motion and functional recovery as well as significant improvement of bone mineral density.

Objective:To explore the changing characteristics of self-efficacy, social support, psychological stress in patients with osteoporotic vertebral compression fractures (OVCFs) receiving conservative treatment at different treatment stages and their correlations with the recovery of lower back function.Methods:A total of 116 patients with acute OVCFs who were admitted to the Affiliated Hospital of Medical School, Ningbo University were selected from January 2017 to May 2019. Oswestry Disability Index (ODI) Questionnaire, General Self Efficacy Scale (GSES) , Perceived Social Support Scale (PSSS) and Perceived Stress Scale (PSS) were used to assess the lower back function, self-efficacy, social support and psychological stress of OVCFs patients. Questionnaires were filled out during outpatient reexamination or in-home follow-up, and the evaluation time was at the time of treatment and 1, 3, 6, and 12 months after conservative treatment. Analysis of variance and SNK- q test were used to explore the characteristics of each score over time, and linear regression analysis was used to explore the effects of GSES, PSSS, and PSS on ODI. Results:With the prolongation of treatment time, ODI, GSES, PSSS and PSS scores of OVCFS patients under conservative treatment showed a downward trend, and the scores at 3, 6 and 12 months after treatment were lower than those at 1 month after conservative treatment ( P<0.05) . The scores at 6 and 12 months after conservative treatment were lower than those at 3 months after conservative treatment ( P<0.05) . The scores at 12 months after conservative treatment were lower than that those at 6 months after conservative treatment ( P<0.05) . GSES, PSSS (total score, in-family support, out-of-family support) and PSS were independent influencing factors of ODI at one month after treatment ( P<0.05) . GSES, PSSS (total score, in-family support) and PSS were the influencing factors of ODI at 3 months after treatment ( P<0.05) . Conclusions:The self-efficacy and social support of conservatively treated patients with OVCFs are positively correlated with their lower back function, while psychological stress will reduce lower back function of such patients. It is suggested to add these non-physical factors to the rehabilitation nursing model and take appropriate intervention measures.

Objective To explore the diagnostic and score value of ultrasound on hemophiliac arthropathy referring to MRI on the diagnosis and score of hemophiliac arthropathy Methods The ultrasound and MRI examinations were performed on 42 joints of 42 hemophilia patients 14 knees 14 ankles and 14 elbows The consistency of ultrasound and magnetic resonance imaging in the detection and score of joint diseases was compared Finally inter-and intra-observer agreement of ultrasound scoring system were tested Results The consistency of ultrasound and magnetic resonance imaging was excellent κ=0 763-0 896 P < 0 001 in the detection of early soft tissue lesions effusion or hemarthrosis synovial hypertrophy hemosiderin excellent κ=0 793 P <0 001 in the detection of cartilage loss poor κ=0 133 P = 0 132 in the detection of erosions and poor κ= 0 100 P = 0 137 in the detection of subchondral cysts The consistency of ultrasound and magnetic resonance imaging was good to excellentκ=0 684-0 833 P < 0 001 in the score of early soft tissue lesions effusion or hemarthrosis synovial hypertrophy and hemosiderin and poor to good κ=0 145 -0 635 P <0 001 in the score of advanced osteochondral lesions cartilage loss and bone erosions The inter-observer agreement was good to excellent κ=0 676-0 870 P <0 001 for early soft tissue lesions and moderate to excellent κ=0 421- 0 75 1 P < 0 001 for advanced osteochondral lesions The intra-observer agreement was good to excellent κ=0 705-0 885 P <0 001 for early soft tissue lesions and moderate to good κ=0 532 -0 732 P <0 001 for advanced osteochondral lesions Conclusions Ultrasound plays an important role in detecting early soft tissue changes effusion or hemarthrosis synovial hypertrophy hemosiderin and cartilage loss which helps follow-up and guide clinical treatment.

Objective To formulate a five-level pediatric emergency triage standard and evaluate the efficacy and reliability of it in determining severity of emergency pediatric patients.Methods According to the assessment methods in Pediatric Advanced Life Support recommended by American Heart Association and American Academy of Pediatrics,we formulated a five-level pediatric emergency triage standard based on the situation of our hospital and analyzed the data one year before and after the application of it.Results Before and after the application of the triage standard,the average satisfaction rate of emergency patients were (81.28 ± 3.97) ％ and (94.13 ± 4.62) ％,and there was significant difference (P ＜ 0.01) ; the proportion of whom became worse during waiting time were 1.83％ (628/34275) and 0.04％ (16/36 187),and there was significant difference (P ＜0.01) ;the average waiting time of emergency admission patients were (12.71 ± 2.32) min and (3.34 ± 1.95) min,and there was significant difference (P ＜0.01) ;the misjudgment rate of severity were 3.78％ (1 296/34 275) and 0.57％ (205/36 187),and there was significant difference (P ＜ 0.05).Conclusion The five-level triage standard is objective,easy to master,and suitable for pediatric triage.It can quickly sort out critical cases from emergency pediatric patients,which can improve the effectiveness of emergency service,make use of medical resources rationally and somewhat solve the problem of overcrowding.

Objective To examine the therapeutic effect of Kummerowia striata (KS) on IgA nephropathy (IgAN) rats.Methods Sixty SD rats were equally randomized into 6 groups after adaptive feeding for 3 days:blank control group,model control group,tripterygium glycosides (TG) group (in the dose of 0.0165 g/kg),and high-,middle-and low-dose KS groups (in the dose of 16.0,8.0,4.0 g/kg respectively).IgAN rat model was established with bovine serum albumin (BSA),lipopolysaccharide (LPS) and carbon tetrachloride.After modeling,rats except those in blank control group received gastric gavage of corresponding drugs for 10 continuous weeks.Levels of 24-hour proteinuria and hematuria in each group were measured,serum levels of total protein (TP),serum albumin (ALB),aspartate aminotransferase (AST),and alanine aminotransferase (ALT) were tested.The pathological changes of renal tissue were observed under light microscope by HE staining.Results Water decoction of KS could significantly decrease the proteinuria and hematuria levels,and reduce renal pathological changes of IgAN model rats.However,water decoction had no effect on indicators of liver function such as TP,ALB,AST,and ALT in IgAN rats.Conclusion KS has certain therapeutic effect on IgAN model rats.