Aim To investigate the regulatory mecha-nisms of donepezil on the expression and enzymatic ac-tivity of cytochrome P450 3A4(CYP3A4),elucidate the synergistic impact of hypoxia on CYP3A4 function,and reveal its potential association with drug-induced cardiotoxicity,particularly QT interval prolongation.Methods Western blot,co-immunoprecipitation,and gene knockdown techniques were employed to evaluate the effects of donepezil and hypoxia on CYP3A4 pro-tein expression.CYP3A4 enzymatic activity was as-sessed using an in vitro incubation system with rat liver microsomes combined with high-performance liquid chromatography(HPLC),and the half-maximal inhib-itory concentration(IC50)was determined.Results Donepezil(10 μmol·L-1)and hypoxia reduced CYP3A4 protein expression to 31.75％and 45.90％of the control levels,respectively.Both interventions activated the gp78-mediated ubiquitin-proteasome path-way,significantly increasing CYP3A4 ubiquitination levels by 2.1-fold compared to the control group,thereby promoting proteasomal degradation.Donepezil inhibited CYP3A4 enzyme activity with an IC50 of 83.4μmol·L-1,and hypoxia synergistically enhanced this inhibitory effect,reducing the IC50 to 20.79 μmol·L-1.Conclusion Donepezil downregulates CYP3A4 function through dual mechanisms involving ubiquitin-mediated proteasomal degradation and direct enzymatic inhibition.Hypoxia potentiates this effect,leading to impaired metabolism of CYP3A4 substrate drugs,ele-vated plasma drug concentrations(1.6-2.3-fold in-crease compared to normal metabolic conditions),and an increased risk of QT interval prolongation and other forms of cardiotoxicity.

Aim To investigate the regulatory mecha-nisms of donepezil on the expression and enzymatic ac-tivity of cytochrome P450 3A4(CYP3A4),elucidate the synergistic impact of hypoxia on CYP3A4 function,and reveal its potential association with drug-induced cardiotoxicity,particularly QT interval prolongation.Methods Western blot,co-immunoprecipitation,and gene knockdown techniques were employed to evaluate the effects of donepezil and hypoxia on CYP3A4 pro-tein expression.CYP3A4 enzymatic activity was as-sessed using an in vitro incubation system with rat liver microsomes combined with high-performance liquid chromatography(HPLC),and the half-maximal inhib-itory concentration(IC50)was determined.Results Donepezil(10 μmol·L-1)and hypoxia reduced CYP3A4 protein expression to 31.75％and 45.90％of the control levels,respectively.Both interventions activated the gp78-mediated ubiquitin-proteasome path-way,significantly increasing CYP3A4 ubiquitination levels by 2.1-fold compared to the control group,thereby promoting proteasomal degradation.Donepezil inhibited CYP3A4 enzyme activity with an IC50 of 83.4μmol·L-1,and hypoxia synergistically enhanced this inhibitory effect,reducing the IC50 to 20.79 μmol·L-1.Conclusion Donepezil downregulates CYP3A4 function through dual mechanisms involving ubiquitin-mediated proteasomal degradation and direct enzymatic inhibition.Hypoxia potentiates this effect,leading to impaired metabolism of CYP3A4 substrate drugs,ele-vated plasma drug concentrations(1.6-2.3-fold in-crease compared to normal metabolic conditions),and an increased risk of QT interval prolongation and other forms of cardiotoxicity.

MHNTs@PDA@ZIF-8 with rod-shaped core-shell structures was synthesized and used as sorbent in magnetic solid phase extraction(MSPE).MHNTs@PDA@ZIF-8-MSPE method coupled with gas chromatography-mass spectrometry(GC-MS)was employed to analyze sixteen kinds of polycyclic aromatic hydrocarbons(PAHs)in tea beverages.Vibrating sample magnetometer(VSM),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),scanning electron microscopy(SEM)and nitrogen adsorption-desorption techniques were used to characterize the MHNTs@PDA@ZIF-8.The results demonstrated that the MHNTs@PDA@ZIF-8 exhibited significant magnetic properties and a large specific surface area.The experimental conditions that could affect MSPE were investigated,including adsorbent dosage,extraction time,desorption time,ionic strength,desorption solvent type,and desorption solvent volume.The optimal conditions were 10 mg of MHNTs@PDA@ZIF-8 as adsorbent,90 s under vortex extraction,and ultrasonic desorption for 60 s with 1 mL ofn-hexane.The sixteen kinds of PAHs showed good linearity in the concentration range of 5-500 μg/L(r2≥0.995).The limits of detection(S/N=3)and quantitation(S/N=10)were in the range of 0.1-0.8 μg/L and 0.3-2.6 μg/L,respectively.The recoveries of the method ranged from 60.9%to 114.7%,with relative standard deviations(n=3)ranging from 0.2%to 9.2%when the addition levels of sixteen kinds of PAHs were 10,50,and 100 μg/L.The method was simple,fast,sensitive and environmentally friendly,and suitable for detecting sixteen kinds of PAHs in tea beverages.

Objective To investigate the preliminary clinical effect of closed reduction and cannulated nail internal fixa-tion for femoral neck fracture assisted by robot navigation and positioning system.Methods From July 2019 to January 2020,16 cases of femoral neck fracture(navigation group)were treated with closed reduction and internal fixation guided by robot system,including 7 males and 9 females,aged 25 to 72 years old with an average of(53.61±5.45)years old;Garden classification of fracture:3 cases of type Ⅰ,3 cases of type Ⅱ,8 cases of type Ⅲ,2 cases of type Ⅳ.Non navigation group(control group):20 cases of femoral neck fracture were treated with closed reduction and hollow nail internal fixation,8 males and 12 females,aged 46 to 70 years old with an average of(55.23±4.64)years old;Garden type Ⅰ in 2 cases,type Ⅱ in 4 cases,type Ⅲ in 11 cases,type Ⅳ in 3 cases.The operation time,fluoroscopy times,guide needle drilling times,screw adjustment times,intraoperative bleeding volume and other indicators of two groups were evaluated.Results Both groups were followed up for 12 to 18 months with an average of(15.6±2.8)months.The fractures of both groups were healed without delayed union and nonunion.There was no significant difference in healing time between two groups(P=0.782).There was no significant differ-ence in Harris scores between two groups at the last follow-up(P=0.813).There was no significant difference in operation time between two groups(P＞0.05).There were significant differences between two groups in fluoroscopy times,guide needle drilling times,hollow screw replacement times,and intraoperative bleeding volume(P＜0.05).Conclusion Closed reduction and hollow screw internal fixation assisted by robot navigation system for femoral neck fracture has the advantages of minimally invasive operation,precise screw placement,and reduction of X-ray radiation damage during operation.

Objective:To compare the clinical effects of acute shortening-lengthening technique with antibiotic calcium sulfate-loaded bone transport technique for the treatment of segmental tibial defects after trauma.Methods:The clinical data of 58 patients with large tibial defects treated by Ilizarov technique in Xi′an Honghui Hospital Affiliated to Xi′an Jiaotong University from May 2014 to December 2019 were retrospectively analyzed. Thirty patients were treated by acute shortening-lengthening (group A), and they were divided into those who were successful in one-time shortening during operation (group A1) and those who needed gradual shortening after operation (group A2) according to different shortening conditions. And 28 patients by antibiotic calcium sulfate-loaded bone transport (group B). The external fixation time (EFT) and external fixation index (EFI) of the two groups were compared. Bone defect healing and limb functions were evaluated according to the Association for the Study and Application of the Method of Ilizarov (ASAMI) criteria. Complications were compared by Paley classification. The measurement data of normal distribution were expressed as ± s, and t-test was used for comparison between groups; the count data were expressed as n(%), and the chi-square test, Fisher exact probability method or Mann-Whitney U test were used for comparison between groups. Results:Patients were followed for(27.5±5.1)months. There was no significant difference in EFT, EFI, bone defect healing and limb functions between the two groups( P>0.05). The incidence of Grade-Ⅱ[41.2% (7/17)], Grade-Ⅲ [47.1% (8/17)] pin-tract infection in group A1 and Grade-Ⅱ[46.2% (6/13)], Grade-Ⅲ pin-tract [53.8% (7/13)] in group A2 was significantly higher than those in group B[14.3% (4/28)], [17.9% (5/28)] ( P<0.05). The number of complications per capita in group A1 [(1.4±0.3) times/case] and in group A2 [(1.5±0.3) times/case]was significantly higher than that in group B [(1.1±0.5) times/case]. Conclusions:Patients can be cured successfully by both acute shortening-lengthening and bone transport techniques. Compared with acute shortening-lengthening group, the complication incidence in antibiotic calcium sulfate-loaded bone transport group was lower, especially, the infection-related complications. Therefore, antibiotic calcium sulfate-loaded bone transport technique has a greater application prospect in patients with large segmental bone defects caused by infection or osteomyelitis.

Objective:To investigate the clinical effects of antibiotic-loaded calcium sulfate-autologous iliac bone combined with sural neurocutaneous flap in the one-stage treatment of chronic calcaneus osteomyelitis plus skin and soft tissue defects.Methods:From January 2013 to September 2019, 48 patients were admitted to Department of Orthopedic Trauma, Xi'an Honghui Hospital Affiliated to Xi'an Jiaotong University for chronic calcaneal osteomyelitis complicated with skin and soft tissue defects. They were divided into 2 groups according to different bone grafts. In group A of 26 patients treated at one stage by antibiotic-loaded calcium sulfate-autologous iliac bone combined with sural neurocutaneous flap, there were 16 males and 10 females with an age of (45.0±11.7) years and an area of skin defect of (56.0±16.7) cm 2. In group B of 22 patients treated at one stage by simple autologous iliac bone combined with sural neurocutaneous flap, there were 13 males and 9 females with an age of (43.6±9.6) years and an area of skin defect of (53.8±16.2) cm 2. The volume of the ilium harvested, fracture healing time, infection control, donor site complications, pain score of visual analogue scale (VAS) and function recovery of the ankle were compared between the 2 groups. Results:There was no significant difference in the preoperative general data between the 2 groups, showing comparability ( P>0.05). The 48 patients were followed up for (15.3±6.0) months. Group A had a significantly smaller volume of the ilium harvested [(67.3±14.1) cm 3] than group B [(90.7±23.5) cm 3], a significantly lower rate of donor site complications [3.8% (1/26)] than group B [31.8% (7/22)], significantly lower VAS pain scores at 6, 12, 24, 48 and 72 hours than group B, and significantly lower WBC count, erythrocyte sedimentation rate and C-reactive protein at 2, 4, 8 weeks after operation than group B (all P<0.05). There was no statistically significant difference between the 2 groups in the infection control rate [96.2% (25/26) versus 77.3% (17/22)], the fracture healing time [(6.2±1.9) months versus (6.4±2.1) months], or the ankle-hindfoot score of AOFAS (The American Orthopaedic Foot and Ankle Society) (83.9±7.2 versus 82.5±8.7) at 6 months after operation (all P>0.05). Conclusion:In one-stage treatment of chronic calcaneal osteomyelitis complicated with skin and soft tissue defects, compared with simple autologous iliac bone combined with sural neurocutaneous flap, antibiotic-loaded calcium sulfate-autologous iliac bone combined with sural neurocutaneous flap can reduce the volume of the ilium harvested, pain score of VAS, and incidence of donor site complications, and improve the recovery of inflammatory indicators, leading to fine clinical effects.

Objective:To compare the clinical efficacy between bone transport technique combined with bone grafting plus internal fixation and simple bone transport technique in the treatment of large segmental bone defects at lower limbs after trauma.Methods:A retrospective study was conducted to analyze the clinical data of 42 patients with large segmental bone defects at lower limbs after trauma who had been treated at Department of Trauma Orthopaedics, Honghui Hospital Affiliated to Medicine College, Xi'an Jiaotong University from September 2015 to September 2019. The patients were divided into 2 groups according to the different methods of repairing bone defects. In group A of 18 patients subjected to bone transport combined with bone grafting plus internal fixation, there were 11 males and 7 females with an age of (35.2±10.3) years, and 12 tibial defects and 6 femoral defects; in group B of 24 patients subjected to simple bone transport, there were 15 males and 9 females with an age of (37.3±9.4) years, and 17 tibial defects and 7 femoral defects. The external fixation time (EFT), external fixation index (EFI), total cure time and complications were recorded and compared between the 2 groups. At the last follow-up, the Ennecking score for limb functional recovery (score/total score 30) and Self-rating Anxiety Scale (SAS) were used to evaluate respectively the functional recovery of the limbs and postoperative anxiety.Results:The 2 groups were comparable because there was no significant difference between them in preoperative general data or follow-up time ( P>0.05). There was no statistically significant difference in the number of surgeries between the 2 groups ( P>0.05). The EFT [(5.9±1.5) months], EFI [(0.45±0.09) months/cm], total treatment time [(16.2±2.4) months], Ennecking score for limb functional recovery (87.0%±8.6%), SAS score [(43.2±9.0) points], and complications per capita [(0.4±0.2) times/case] in group A were significantly better than those in group B [(15.3±4.2) months, (1.19±0.28) months/cm, (19.7±3.5) months, (77.3%±9.2%), (58.2±9.3) points, and (1.2±0.5) times/case] (all P<0.05). Conclusion:In the treatment of large segmental bone defects at lower limbs, compared with simple bone transport technique, bone transport technique combined with bone grafting plus internal fixation has advantages of shorter external fixation time and overall cure time, a lower rate of complications, and better functional recovery of the limbs.

Objective:To analyze the therapeutic effect of 3D printing technology combined with locking plate fixation on femoral shaft fracture in patients with femoral deformity.Methods:The clinical data of 33 patients with femoral shaft fracture with femoral deformity who met the inclusion criteria and underwent locking plate fixation in the Xi′an Honghui Hospital Affiliated to Xi′an Jiaotong University from June 2014 to December 2020 were retrospectively analyzed. The patients were divided into 3D printing group ( n=18) and control group ( n=15) according to whether 3D printing was performed before operation. The 3D printing group including 11 males and 7 females with an age of (46.78±13.76) years.The control group including 9 males and 6 females with an age of (48.20±14.27) years.The operation time, intraoperative blood loss, fracture healing time and complications of the two groups were recorded. Visual analogue scale (VAS) scores of pain were evaluated before and 6, 12, 24, 48 and 72 h after operation. According to the Harris hip score, the Hospital for Special Surgery (HSS) knee score and The MOS 36-item short-from Health Survey (SF-36), the hip and knee function and quality of life of the patients before and 12 months after injury were evaluated. The measurement data were represented as mean±standard deviation( ± s), and the comparison between groups was conducted using the t-test; the comparison of count data between groups was conducted by Chi-square test or Fisher exact probability. Results:The operation time, intraoperative blood loss, and incidence of complications in the 3D printing group were (91.50±9.07) min, (191.11±16.01) mL, and 0(0/18), respectively, and those in the control group were (118.07±14.19) min, (270.27±17.59) mL, and 26.7% (4/15), the differences between the two groups were statistically significant ( P <0.05). The pain VAS scores of the 3D printing group were significantly better than those of the control group at 6, 12, 24, 48, and 72 h after operation ( P<0.05). There were no differences in fracture healing time and preoperative pain VAS between the two groups( P>0.05). There were no significant differences in hip function, knee function and quality of life scores between the two groups before injury and 12 months after injury( P>0.05). Conclusion:In the treatment of femoral shaft fractures in patients with femoral deformity with locking plate fixation, the application of 3D printing technology can be used for preoperative design and plate preshaping, which can shorten the operation time, reduce the amount of intraoperative blood loss, reduce the VAS of pain and the incidence of complications, improve the satisfaction of surgery, and provide a new option for the treatment of femoral shaft fractures in patients with femoral deformity.