As a new generation of time-of-flight mass spectrometry,multiple-reflection time-of-flight mass spectrometry(MR-TOF-MS)has been increasingly applied in the fields such as nuclear physics,chemistry,and biology due to its ultra-high resolution and rapid analysis capabilities.However,the analytical performance of MR-TOF-MS largely depends on the ion bunch state entering the mass analyzer.In this study,a rectangular ion trap(RIT)was developed,designed and processed using printed circuit board technology,as an ion accumulating and focusing device for MR-TOF mass analyzer.Compared to traditional ion traps composed of two sets of planar electrodes,this RIT had higher voltage utilization efficiency,resulting in more efficient ion collection and focusing.The ions were cooled to a sufficiently small bunch for precise mass measurement with MR-TOF-MS mass spectrometry in only 1 ms of cooling time in the RIT,then orthogonally ejected to the MR-TOF mass spectrometer for mass analysis.Experimental results indicated that the working cycle,ion flux,and ion focusing state of the RIT fully met the requirements of the MR-TOF mass analyzer.When coupled with the MR-TOF mass analyzer,the RIT enabled MR-TOF-MS to achieve a mass resolution of 1.5×105.

A method was developed for determination of dilauryl thiodipropionate(DLTDP)in fried foods by coupling solid-phase extraction(SPE)pretreatment with reverse-phase liquid chromatography-tandem mass spectrometry(RPLC-MS/MS)detection.Samples were extracted with n-hexane as the solvent,purified using a neutral alumina SPE cartridge,and finally analyzed by RPLC-MS/MS.Quantitative analysis was performed using matrix-matched calibration curves combined with an external standard method under optimal experimental conditions.The results showed that DLTDP exhibited good linearity in the range of 2.0-50.0 μg/L,with a correlation coefficient(R2)≥0.999.The limit of detection(LOD)and the limit of quantification(LOQ)of the method were 0.15 mg/kg and 0.5 mg/kg,respectively.The mean recoveries at three fortification levels(0.5,1.0,and 200 mg/kg)in different samples ranged from 84.8%to 96.8%,with the relative standard deviations(RSDs)all less than 8.0%.The developed method was highly sensitive,accurate and reliable,and easy to operate,making it well suited for the routine quantitative analysis of DLTDP in fried foods.

Aim To evaluate the bioequivalence of two oral preparations of rivaroxaban tablets(test preparation T and refe-rence preparation R)in fasting/postprandibular state in healthy Chinese subjects.Methods A randomized,open,single-dose,four-cycle,completely repeated crossover experiment was used in this study.A total of 70 healthy male and female subjects were enrolled,including 38 subjects in the fasting group and 32 sub-jects in the postprandial group.Rivaroxaban tablets(2.5 mg/tablet)were taken orally once per cycle and their reference preparations were tested.The plasma rivaroxaban concentration was determined by LC-MS/MS method.The pharmacokinetic parameters of rivaroxaban tablets were calculated by WinNonlin software,and the parameters were analyzed and processed.Re-sults The PK parameters of rivaroxaban tablets and reference preparations in fasting group were as follows:Cmax was(72.48±17.08)and(66.36±15.64)μg·L-1,respectively.AUC0-t were(383.49±101.06)and(370.43±102.16)h·ng·mL-1,and AUC0-inr were(389.58±102.28)and(375.84±103.01)h·μg·L-,respectively.Main PK parameters of subjects taking rivaroxaban tablets orally after meals:Cmax were(66.48±15.64 and 60.87±13.44)μg·L-1,AUC0-t were(404.44±72.58)and(381.80±79.93)h·μg·L-1,re-spectively.AUC0_inf was(410.88±73.55)and(393.64±69.71)h·μg·L-1,respectively.Under fasting and postmeal conditions,subjects took rivaroxaban test and reference prepara-tion orally,one tablet(2.5 mg/tablet)each time.The geometric mean of the main pharmacokinetic parameters of rivaroxaban in plasma(Cmax,AUC0-t,AUC0-inf)and their corresponding values had a 90％confidence interval ranging from 80.00％to 125.00％.No serious adverse events or unexpected adverse e-vents occurred in both groups.Conclusion Rivaroxaban tablets are bioequivalent and safe in vivo under fasting and postprandial conditions.

Objective:To compare the efficacy of robot system-assisted versus freehand screw revision for ankylosing spondylitis (AS) with lower cervical fractures.Methods:A multicenter retrospective cohort study was conducted to analyze the clinical data of 57 patients with AS combined with lower cervical fractures admitted to Honghui Hospital Affiliated to Xi'an Jiaotong University School of Medicine, Henan Provincial People's Hospital, Zhengzhou Orthopedic Hospital, and Qilu Hospital of Shandong University, including 46 males and 11 females, aged 38-77 years [(65.4±9.5)years]. Injury segments involved C 3 in 7 patients, C 4 in 13, C 5 in 25, C 6 in 10, and C 7 in 2. All the patients underwent revision surgery, among whom, 22 patients were treated with robot system-assisted cervical pedicle screw placement (robot nailing group, with 190 screws), and 35 with freehand cervical pedicle screw placement (freehand nailing group, with 300 screws). The operative duration, intraoperative bleeding volume, frequency of intraoperative fluoroscopy, incision length, and length of hospital stay of the two groups were compared; the time of single nscrew insertion, the number of single nail revisions, the distance between screws and the anterior cortex, the accuracy of screw placement of grade 0 and grade 0+1 were recorded in the two groups. The visual analogue scale (VAS), Japanese Orthopedic Society (JOA) score, neck dysfunction index (NDI), American Spine Injury Association (ASIA) classification before operation, at 3 days, 3 months after operation and at the last follow-up were compared between the two groups. The complication rate was also noted. Results:All the patients were followed up for 12-16 months [(14.3±2.1)months]. The operative duration, intraoperative bleeding volume, and frequency of intraoperative fluoroscopy were (186.4±12.9)minutes, (486.1±68.6)ml, and (3.4±1.3)times in the robot nailing group, which were shorter or less than (206.7±14.4)minutes, (660.3±45.2)ml, and (13.5±3.6)times in the freehand nailing group ( P<0.01). The incision length was (9.4±2.4)cm in the robot nailing group, longer than (5.6±1.2)cm in the freehand nailing group ( P<0.01), and the length of hospital stay was (3.7±0.4)days, shorter than (4.4±1.4)days in the freehand nailing group ( P<0.01). The length of single nail insertion, the number of single nail revision, and the distance between the screws and the front cortex were (6.5±0.4)minutes, (1.1±0.1)times, and (3.5±1.3)mm in the robot nailing group, which were shorter or less than (11.6±0.2)minutes, (1.5±0.2)times, and (12.4±4.7)mm in the freehand nailing group ( P<0.01). The accuracy of the screw placement in the robot nailing group was 90.0% (171/190) and 95.8% (182/190) with level 0 and 0+1 screws, better than 80.0% (240/300) and 89.0% (267/300) in the freehand nailing group ( P<0.05). There was no significant difference in VAS, JOA score, NDI, or ASIA grading between the two groups before operation ( P>0.05). The VAS, JOA, and NDI scores at 3 days after operation were (3.1±0.6)points, (12.1±1.2)points, and (15.6±2.9)points, respectively in the robot nailing group, which were better than (5.0±1.4)points, (11.3±1.1)points and (22.5±3.7)points, respectively in the freehand nailing group ( P<0.05). No statistically significant difference was observed in the ASIA grade between the two groups at 3 days after operation ( P>0.05). There were no significant differences in VAS, JOA, NDI scores, or ASIA grading between the two groups at 3 months after operation and at the last follow-up ( P>0.05). Compared with those before operation, the VAS, JOA, NDI scores, and ASIA grading were significantly improved at 3 days, 3 months after operation and at the last follow-up in the two groups, which were further improved with the passage of time. Two patients in the robot nailing group had pneumonia, with a complication rate of 9% (2/22), while 2 patients in the freehand nailing group had dural sac rupture and cerebrospinal fluid leakage and 3 had lung infection after operation, with a complication rate of 14% (5/35) ( P<0.05). Conclusion:Compared with freehand nailing, the robot system-assisted nailing revision for AS with lower cervical fracture has more advantages in terms of the operative duration, length of hospital stay, intraoperative bleeding volume, frequency of intraoperative fluoroscopy nailing speed and accuracy, screw holding force, early pain relief, function restoration, and complication rate, despite longer surgical incision.

Objective:To compare the efficacy of laminoplasty via the intermuscular approach or posterior midline approach for treating spinal cord injury without radiographic abnormality (SCIWORA).Methods:A multi-center retrospective cohort study was conducted to analyze the clinical data of 135 patients with SCIWORA admitted to Honghui Hospital Affiliated to Xi'an Jiaotong University School of Medicine, Xi'an No.5 Hospital, Henan Provincial People's Hospital, Zhengzhou Orthopedic Hospital, Xuanwu Hospital of Capital Medical University from February 2021 to June 2023, including 75 males and 60 females, aged 35-78 years [(55.3±8.1)years]. The injury segments involved C 3-C 6. All the patients underwent posterior cervical open-door laminoplasty, among whom 70 patients were treated via the intermuscular approach (intermuscular group) and 65 via the posterior midline approach (posterior midline group). The operation duration, intraoperative blood loss, postoperative drainage volume, and length of hospital stay were recorded. The visual analogue scale (VAS) score, Japanese Orthopedic Association (JOA) score, neck disability index (NDI), Barthel index, cervical Cobb angle, and cervical range of motion (ROM) were measured preoperatively, at 3, 6, 12 months postoperatively and at the final follow-up. The American Spinal Injury Association (ASIA) scale was evaluated preoperatively, at 3, 12 months postoperatively and at the final follow-up. The postoperative complication rate was recorded as well. Results:All the patients were followed up for 15-19 months [(16.3±1.6)months]. The operation duration, intraoperative blood loss, postoperative drainage and length of hospital stay were (125.0±23.0)minutes, (210.4±34.8)ml, and (165.3±23.7)ml, and (5.3±0.1)days in the intermuscular group, which were significantly shorter or less than (168.0±27.6)minutes, (260.2±45.3)ml, (196.4±31.6)ml, and (6.4±0.2)days in the posterior midline group ( P<0.01). The preoperative VAS score, JOA score, NDI and Barthel index showed no significant differences between the two groups ( P>0.05). The VAS score and JOA score also showed no significant differences between the two groups at 3, 6, 12 months postoperatively or at the final follow-up ( P>0.05). The NDI and Barthel index also showed no significant differences between the two groups at 3 months postoperatively ( P>0.05). At 6, 12 months postoperatively and at the final follow-up, the NDI were (15.4±2.5)points, (11.8±2.1)points and (8.6±1.5)points in the intermuscular group, significantly lower than (19.1±3.4)points, (14.3±2.4)points and (11.9±1.4)points in the posterior midline group ( P<0.01). At 6, 12 months postoperatively and at the final follow-up, the Barthel index were (71.4±6.2)points, (83.4±5.8)points and (89.2±7.1)points in the intermuscular group, significantly higher than (59.6±4.7)points, (74.2±3.9)points and (78.8±6.2)points in the posterior midline group ( P<0.01). Both groups showed significant improvements in VAS score, JOA score, NDI and Barthel index at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively ( P<0.05). Among them, the VAS score, NDI and Barthel index were further improved over time ( P<0.05). Simultaneously, the JOA score was significantly improved at 6, 12 months postoperatively and at the last follow-up when compared to that at 3 months postoperatively ( P<0.05), with no significant difference at later time points between the two groups ( P>0.05). The preoperative cervical Cobb angle and ROM showed no significant differences between the two groups ( P>0.05). There was no significant difference in the Cobb angle between the two groups at 3, 6 or 12 months postoperatively ( P>0.05), while it was (13.6±2.4)° in the intermuscular group at the final follow-up, significantly larger than (10.4±2.8)° in the posterior midline group ( P<0.01). At 3, 6, 12 months postoperatively and at the final follow-up, the cervical ROM were (34.1±6.4)°, (32.6±7.3)°, (31.8±9.1)° and (29.6±8.7)° in the intermuscular group, significantly larger than (23.7±8.3)°, (22.3±7.8)°, (22.5±8.1)° and (20.6±9.3)° in the posterior midline group ( P<0.01). In the intermuscular group, the cervical Cobb angle showed no significant changes at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively ( P>0.05). In the posterior midline group, the Cobb angles were significantly reduced at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively ( P<0.05), showing significant decrease at 12 months postoperatively and at the final follow-up from those at 3, 6 months postoperatively ( P<0.05), no significant difference at 6 months postoperatively from that at 3 months postoperatively ( P>0.05), and significant decrease at the final follow-up from that at 12 months postoperatively ( P>0.05). In the intermuscular group, the cervical ROM were significantly improved at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively and showed further improvement over time ( P<0.05). In the posterior midline group, the cervical ROM were significantly improved at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively ( P<0.05), showing significant decreases at 6, 12 months postoperatively and at the final follow-up from that at 3 months postoperatively ( P<0.05), significant decreases at the final follow-up from those at 6, 12 months postoperatively ( P<0.05), and no significant difference at 12 months postoperatively from that at 6 months postoperatively ( P>0.05). The ASIA grades showed no significant difference between the two groups preoperatively, at 3, 12 months postoperatively and at the final follow-up ( P>0.05) , but were gradually improved over time in both groups ( P<0.05). The postoperative complication rate was 9%(6/70) in the intermuscular group, significantly lower than 48%(31/65) in the posterior midline group ( P<0.01). Conclusion:Compared to the posterior midline approach, the intermuscular approach for laminoplasty in patients with SCIWORA possesses advantages, including shorter operative time and length of hospital stay, reduced intraoperative blood loss and postoperative drainage, less postoperative neck disability, higher daily life quality, better long-term preservation of cervical lordosis and motion, and a lower complication rate.

For middle-aged and elderly patients with conditions such as spinal fractures and degenerative spinal diseases, spinal internal fixation is a core surgical procedure for reconstructing spinal stability, heavily relying on the biomechanical stability provided by pedicle screw systems. Whereas, these patients are often complicated by osteoporosis that can significantly compromise the stability of the bone-pedicle screw interface, leading to a marked increase in pedicle screw loosening and surgical failure rates. The bone cement-augmented pedicle screw technique, which involves injecting bone cement into the vertebral body or screw trajectory to optimize the mechanical properties of the bone-pedicle screw composite, has been proven to significantly enhance fixation strength and effectively prevent screw-related failures, thereby reducing the incidence of internal fixation failure in high-risk populations undergoing spinal fusion. However, the widespread clinical application of this technique has faced challenges such as inaccurate clinical decision-making (indication and contraindication selection), non-standardized operative practices, and insufficient awareness of complication prevention, resulting in considerable variability in clinical outcomes and even severe complications. To address this, Prof. Luo Fei from First Affiliated Hospital of Army Medical University initiated the project and the Chinese Association Orthopaedic Surgeons organized relevant experts to develop the Evidence-based clinical practice guideline for bone cement-augmented pedicle screw technique ( version 2025), based on current evidence. The guidelines put forward 8 recommendations regarding the clinical value, scope of application, and operational standards of the technique, aiming to provide evidence-based medical support and technical standardization for clinical decision-making.

Objective:To analyze the epidemiological characteristics of cases involving monkey injuries at medical institutions surrounding Qianlingshan Park in Guiyang City, and to provide a reference basis for preventive measures to reduce monkey injuries and standardized post-exposure treatment.Methods:A retrospective cross-sectional study was conducted, collecting 1 900 cases of monkey-induced injuries in Qianlingshan Park treated at the outpatient clinic of Guizhou Provincial Center for Disease Control and Prevention and the Department of Surgery at Qianling Hospital, Guiyang City, from 2021 to 2024. Statistical analysis was performed using Pearson′s chi-square test.Results:Total of 1 900 cases of monkey-related injuries in Qianlingshan Park were collected from 2021 to 2024. The exposure time distribution exhibited significant seasonality, with 48.58% of cases occurring during July and August, totaling 923 cases, indicating a peak in the summer. There were 774 male patients and 1 126 female patients, with a ratio of 1∶1.45.and significant differences were observed between different age groups and genders (χ2=195.00, P<0.001), with the highest number of cases occurring in the 0-9 and 20-29 age groups, accounting for 22.05%(419 cases) and 21.79%(414 cases), respectively. The upper limbs were the most common injury site, accounting for 50.84% of the total cases(966 cases in total), with significant differences between gender and injury location (χ2=22.00, P<0.001), Among females, the proportion of injuries to the upper and lower limbs (30.11% and 16.47%, respectively) was higher than that among males (20.74% and 8.63%, respectively). The majority of injuries were classified as Grade Ⅲ, making up 57.38% of cases(1 069 cases in total). Self-treatment after exposure was the most common approach(60.44%), with significant differences observed between wound severity and treatment method (χ2=6.90, P=0.032), Patients with Grade Ⅱ and Grade Ⅲ wounds were more likely to choose self-management (26.84% and 33.23%, respectively) than outpatient management (15.14% and 24.15%). Approximately 98.05% (1 863 cases) of monkey-injured patients had received rabies vaccinations. Conclusions:This study analyzes monkey-related injuries in Qianlingshan Park from 2021 to 2024, clarifying the temporal distribution of injuries, demographic characteristics, injury sites, and treatment methods. The findings provide references for optimizing human-monkey conflict management and the prevention and control of zoonotic diseases in urban ecological parks.

Objective:To analyze the epidemiological characteristics of cases involving monkey injuries at medical institutions surrounding Qianlingshan Park in Guiyang City, and to provide a reference basis for preventive measures to reduce monkey injuries and standardized post-exposure treatment.Methods:A retrospective cross-sectional study was conducted, collecting 1 900 cases of monkey-induced injuries in Qianlingshan Park treated at the outpatient clinic of Guizhou Provincial Center for Disease Control and Prevention and the Department of Surgery at Qianling Hospital, Guiyang City, from 2021 to 2024. Statistical analysis was performed using Pearson′s chi-square test.Results:Total of 1 900 cases of monkey-related injuries in Qianlingshan Park were collected from 2021 to 2024. The exposure time distribution exhibited significant seasonality, with 48.58% of cases occurring during July and August, totaling 923 cases, indicating a peak in the summer. There were 774 male patients and 1 126 female patients, with a ratio of 1∶1.45.and significant differences were observed between different age groups and genders (χ2=195.00, P<0.001), with the highest number of cases occurring in the 0-9 and 20-29 age groups, accounting for 22.05%(419 cases) and 21.79%(414 cases), respectively. The upper limbs were the most common injury site, accounting for 50.84% of the total cases(966 cases in total), with significant differences between gender and injury location (χ2=22.00, P<0.001), Among females, the proportion of injuries to the upper and lower limbs (30.11% and 16.47%, respectively) was higher than that among males (20.74% and 8.63%, respectively). The majority of injuries were classified as Grade Ⅲ, making up 57.38% of cases(1 069 cases in total). Self-treatment after exposure was the most common approach(60.44%), with significant differences observed between wound severity and treatment method (χ2=6.90, P=0.032), Patients with Grade Ⅱ and Grade Ⅲ wounds were more likely to choose self-management (26.84% and 33.23%, respectively) than outpatient management (15.14% and 24.15%). Approximately 98.05% (1 863 cases) of monkey-injured patients had received rabies vaccinations. Conclusions:This study analyzes monkey-related injuries in Qianlingshan Park from 2021 to 2024, clarifying the temporal distribution of injuries, demographic characteristics, injury sites, and treatment methods. The findings provide references for optimizing human-monkey conflict management and the prevention and control of zoonotic diseases in urban ecological parks.

Isoflavones which mainly distributed in leguminous plants have plenty of health benefits.Isoflavone synthase(IFS)is a membrane-associated cytochrome P450 enzyme(CYP450)which carries out the unique aryl-ring migration and hydroxylation.So far,few crystal structures of plant P450s have been obtained.We determined the crystal structure of IFS from Medicago truncatula at 1.9 ? by MAD method using a selenomethionine substituted crystal and conducted molecular docking and mutagenesis study.The structure of IFS complexed with imidazole exhibits the helix Ⅰa-loop-helix Ⅰβ motif which cor-responds to helix Ⅰ of other P450s.Compared with structures of common P450s,IFS/imidazole structure contains an extra domain,i.e.,the γ-domain.The structure reveals a homodimer in which the γ-domain of one molecule interacts with the β-domain of another.The plane of heme group makes an angle of ap-proximately 40° with the helix Ⅰa-loop-helix Ⅰβ motif.Molecular docking combined with mutagenesis study suggested that Trp-128 and Asp-300 might play important roles in substrate binding and recogni-tion.Phe-301,Ser-303 and Gly-305 from the helix Ⅰa-loop-helix Ⅰβ motif may play important roles in the aryl-ring migration.These novel structural features reveal insights into the unique reaction mechanism of IFS and provide a basis for engineering IFS in leguminous crops for health purpose.

Aim To evaluate the bioequivalence of two oral preparations of rivaroxaban tablets(test preparation T and refe-rence preparation R)in fasting/postprandibular state in healthy Chinese subjects.Methods A randomized,open,single-dose,four-cycle,completely repeated crossover experiment was used in this study.A total of 70 healthy male and female subjects were enrolled,including 38 subjects in the fasting group and 32 sub-jects in the postprandial group.Rivaroxaban tablets(2.5 mg/tablet)were taken orally once per cycle and their reference preparations were tested.The plasma rivaroxaban concentration was determined by LC-MS/MS method.The pharmacokinetic parameters of rivaroxaban tablets were calculated by WinNonlin software,and the parameters were analyzed and processed.Re-sults The PK parameters of rivaroxaban tablets and reference preparations in fasting group were as follows:Cmax was(72.48±17.08)and(66.36±15.64)μg·L-1,respectively.AUC0-t were(383.49±101.06)and(370.43±102.16)h·ng·mL-1,and AUC0-inr were(389.58±102.28)and(375.84±103.01)h·μg·L-,respectively.Main PK parameters of subjects taking rivaroxaban tablets orally after meals:Cmax were(66.48±15.64 and 60.87±13.44)μg·L-1,AUC0-t were(404.44±72.58)and(381.80±79.93)h·μg·L-1,re-spectively.AUC0_inf was(410.88±73.55)and(393.64±69.71)h·μg·L-1,respectively.Under fasting and postmeal conditions,subjects took rivaroxaban test and reference prepara-tion orally,one tablet(2.5 mg/tablet)each time.The geometric mean of the main pharmacokinetic parameters of rivaroxaban in plasma(Cmax,AUC0-t,AUC0-inf)and their corresponding values had a 90％confidence interval ranging from 80.00％to 125.00％.No serious adverse events or unexpected adverse e-vents occurred in both groups.Conclusion Rivaroxaban tablets are bioequivalent and safe in vivo under fasting and postprandial conditions.