Objective To investigate the toxicokinetic differences of 3,4-methylenedioxy-N-methylamphetamine(MDMA)and its metabolite 4,5-methylene dioxy amphetamine(MDA)in rats af-ter single and continuous administration of MDMA,providing reference data for the forensic identifica-tion of MDMA.Methods A total of 24 rats in the single administration group were randomly divided into 5,10 and 20 mg/kg experimental groups and the control group,with 6 rats in each group.The ex-perimental group was given intraperitoneal injection of MDMA,and the control group was given intraperi-toneal injection of the same volume of normal saline as the experimental group.The amount of 0.5 mL blood was collected from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.In the continuous administration group,24 rats were randomly divided into the experi-mental group(18 rats)and the control group(6 rats).The experimental group was given MDMA 7 d by continuous intraperitoneal injection in increments of 5,7,9,11,13,15,17 mg/kg per day,respectively,while the control group was given the same volume of normal saline as the experimental group by in-traperitoneal injection.On the eighth day,the experimental rats were randomly divided into 5,10 and 20 mg/kg dose groups,with 6 rats in each group.MDMA was injected intraperitoneally,and the con-trol group was injected intraperitoneally with the same volume of normal saline as the experimental group.On the eighth day,0.5 mL of blood was taken from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.Liquid chromatography-triple quadrupole tandem mass spectrometry was used to detect MDMA and MDA levels,and statistical software was employed for data analysis.Results In the single-administration group,peak concentrations of MDMA and MDA were reached at 5 min and 1 h after administration,respectively,with the largest detection time limit of 12 h.In the continuous administration group,peak concentrations were reached at 30 min and 1.5 h af-ter administration,respectively,with the largest detection time limit of 10 h.Nonlinear fitting equations for the concentration ratio of MDMA and MDA in plasma and administration time in the single-administration group and continuous administration group were as follows:T=10.362C-1.183,R2=0.974 6;T=7.397 3C-0.694,R2=0.961 5(T:injection time;C:concentration ratio of MDMA to MDA in plasma).Conclusions The toxicokinetic data of MDMA and its metabolite MDA in rats,obtained through single and continuous administration,including peak concentration,peak time,detection time limit,and the relationship between concentration ratio and administration time,provide a theoretical and data foundation for relevant forensic identification.

AIM To study the amino acids and proteins in 16 batches of commercial fish swim-bladders with different origins.METHODS A high performance liquid chromatography method based on pre-column derivatization using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate(AQC)was developed for the determination of contents and components of 17 amino acids in fish swim-bladders.Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)was performed to analyze the molecular weight distribution of proteins from different fish swim-bladders,and proteins in fish swim-bladders were identified by proteomics method.RESULTS The result showed that the determination of 17 amino acids had a good linear relationship(R2≥0.998 0).The average recovery rate was 85.62%-109.60%and the relative standard deviations of precision,stability and repeatability were less than 3.5%.The total content of the 17 amino acids in 16 batches of fish swim-bladders ranged from 468.31 mg/g to 620.05 mg/g.A total of 688 proteins including 11 collagens were identified from 16 batches of fish swim-bladder samples and a plenty of low-abundance proteins at 52-95 kDa were also detected in fish swim-bladders by SDS-PAGE.CONCLUSION This study provides a good reference for the quality evaluation and further utilization of fish swim-bladders.

As a potent narcotic opioid analgesic,fentanyl has been used as intravenous anesthesia for clinical procedures while also being abused by drug users,resulting in an increasing number of deaths year by year,and thus it is urgent to develop rapid screening methods for fentanyl.In this study,by using a binary metal-organic framework MIL-88B(Fe/Ni)as an electrocatalyst,an electrochemical sensor based on multi-walled carbon nanotubes(MWCNTs)modified glassy carbon electrode(GCE)was constructed for rapid detection of fentanyl.The morphology,crystal structure and elemental characteristics of the synthesized MIL-88B(Fe/Ni)/MWCNTs and MIL-88B(Fe/Ni)composites were confirmed by scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).In addition,the electrochemical characterization also revealed that the synthesized MIL-88B(Fe/Ni)/MWCNTs composites modified GCE possessed low electrochemical impedance and large electrochemical surface area with ultra-high sensitivity to fentanyl.The experimental conditions for the electrochemical detection of fentanyl were optimized and the limit of detection(LOD,3Sb/M)for fentanyl was 0.015 μmol/L with a linear range of 0.04-10 μmol/L,and the reproducibility,selectivity and stability were all favorable.In addition,the developed sensor showed satisfactory performance in real samples,with recoveries ranging from 58.6%to 81.5%and from 82.7%to 97.5%in urine and blood,respectively,at concentration levels of 0.2-1.0 μmol/L.The proposed MIL-88B(Fe/Ni)/MWCNTs composite could be used as a novel electrode material for electrochemical detection of fentanyl,and had great potential for rapid detection of fentanyl in public security anti-drug or medical emergency.

Chemical cleaning and disinfection are crucial steps for eliminating infection in root canal treatment.However,irrigant selection or irrigation procedures are far from clear.The vapor lock effect in the apical region has yet to be solved,impeding irrigation efficacy and resulting in residual infections and compromised treatment outcomes.Additionally,ambiguous clinical indications for root canal medication and non-standardized dressing protocols must be clarified.Inappropriate intracanal medication may present side effects and jeopardize the therapeutic outcomes.Indeed,clinicians have been aware of these concerns for years.Based on the current evidence of studies,this article reviews the properties of various irrigants and intracanal medicaments and elucidates their effectiveness and interactions.The evolution of different kinetic irrigation methods,their effects,limitations,the paradigm shift,current indications,and effective operational procedures regarding intracanal medication are also discussed.This expert consensus aims to establish the clinical operation guidelines for root canal irrigation and a position statement on intracanal medication,thus facilitating a better understanding of infection control,standardizing clinical practice,and ultimately improving the success of endodontic therapy.

Objective To analyze the stress changes of thoracic vertebra(T)11-sacrum(S)titanium rods in patients with ankylosing spondylitis after vertebral column decancellation(VCD)osteotomy,and provide reference for the selection and improvement of titanium rods before surgery.Methods The original data of the continuous scanning tomographic images of patients with ankylosing spondylitis after VCD osteotomy were imported into Mimics 21.0 in DICOM format,and T11-S vertebrae,screws and titanium rods were respectively reconstructed.They were imported into 3-Matic to establish a preliminary geometric modeling,and then processed with noise removal,paving,smoothing,etc.The improved model was imported into Hypermesh 10 software for grid division,and the material was imported into ANSYS 19.2 to display the finite element model after attribute assignment,Set the boundary and load conditions,and measure the stress value at the connection between the screw and the titanium rod.Results Under neutral position,forward bending,lateral bending,and axial rotation conditions,the titanium rod had the highest stress at the upper vertebrae(T11)and the lowest stress at the top vertebrae(L3);Under the backward extension condition,the titanium rod has the highest stress at the lower end vertebra(L5).Conclusion In the upper and lower vertebrae,it is possible to consider increasing the diameter of the titanium rod,enhancing its hardness,or changing it to a double rod.

Objective To measure the distance between the lateral compression Ⅱ(LC-Ⅱ)screw guide needle and the surrounding important structures around the anterior inferior iliac spine in pelvic fractures and to locate the needle point,so as to provide anatomical reference for clinical nail placement.Methods Totally 40 adult gross specimens of embalming were implanted with LC-Ⅱ screw guide needle under the surveillance of C-arm machine,and the specimens were dissected.The shortest distance between the insertion point and the lateral femoral cutaneous nerve,femoral nerve,femoral artery,femoral vein,anterior superior iliac spine and inguinal ligament was measured.The triangle was constructed between the insertion point,anterior superior iliac spine and inguinal ligament,and the exact location of the entry point was calculated.Results The average distance between the insertion point of the male needle and the femoral vein was(50.67±7.29)mm＞the anterior superior iliac spine(43.83±7.58)mm＞the femoral artery(38.35±6.63)mm＞the femoral nerve(31.17±1.67)mm=the inguinal ligament(28.69±6.59)mm＞the lateral femoral cutaneous nerve(7.98±3.81)mm.The mean distance between the insertion point of the female needle and the anterior superior iliac spine was(45.28±7.07)mm=femoral vein(43.72±6.89)mm＞femoral artery(33.76±6.33)mm＞femoral nerve(25.66±6.46)mm=inguinal ligament(23.22±5.00)mm＞lateral femoral cutaneous nerve(8.97±4.76)mm.The projection distance of the entry point was 31.77 mm for men and 38.41 mm for women.The Angle b was 42.81°for men and 31.71° for women.Conclusion The lateral femoral cutaneous nerve is most vulnerable to injury when LC-Ⅱ screw is inserted,and the risk of injury has nothing to do with sex.The insertion point positioning method a and b made LC-Ⅱ screw placement quickly,safely and accurately,and reduced fluoroscopy time and frequency.

Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75％(27/36);boys accounted for 64％(23/36).Among the 36 neonates,31(86％)had disease onset within 3 days after birth,and 19(53％)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61％)had left cerebral infarction and 13(36％)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75％)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72％)and seizures in 10 neonates(34％).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33％,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44％(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.

Objective Mobile artificial lumbar complex(MALC)which suitable for reconstruction after subtotal lumbar resection in goats was developed,and to test stability of the complex and postoperative lumbar segmental motor function.Methods Eighteen male boer goats aged from 1 to 2 years old(weighted from 35 to 45 kg)were selected and divided into con-trol group,fusion group and non-fusion group,with 6 goats in each group.According to preoperative CT scans and MRI exami-nations of lumbar,the goat MALC was designed and performed by 3D printed for non-fusion group.Operation was performed on three groups respectively,and only vertebral body and disc were exposed in control group.In fusion group,L4 part of vertebral body and the upper and lower complete disc tissues were removed,and the lumbar spine bone plate fixation was performed with titanium mesh bone grafting.In non-fusion group,vertebral body and disc were removed in the same way,and MALC was im-planted.AP and lateral X-rays of lumbar vertebrae in goat were taken at 6 months after surgery,in order to understand whether the plant was dislocated,displaced and fractured.Biomechanical tests were performed on the specimens by mechanical instru-ment to measure range of motion(ROM)of L2,3,L,4,L4,5intervertebral space and the overall ROM of L2-5 lumbar vertebrae.Results MALC of lumbar vertebra was designed by 3D printing,and its component artificial vertebrae and upper and lower ar-tificial end plates were manufactured.The semi-spherical structure was fabricated by precision lathe using high-crosslinked polyethylene material,and the prosthesis was assembled.Postoperative AP and lateral X-rays of lumbar vertebra at 6 months showed the implant position of implant and MALC were good without displacement and dislocation.In vitro biomechanical test of lumbar vertebrae specimens:(1)There were no statistical significance in ROM of lumbar intervertebral space flexion and extension,lateral flexion and rotation on L.4 and L4,5,between non-fusion group and control group(P＞0.05),while ROM of fu-sion group was significantly reduced compared with the other two groups(P＜0.05).There were no significant difference in ROM of L2.3 intervertebral flexion and extension,lateral flexion and rotation between non-fusion group and control group(P＞0.05),while fusion group was significantly increased compared with the other two groups(P＜0.001).(2)There was no signifi-cant difference in overall lumbar ROM of L2-5(P＞0.05).Conclusion The individual MALC could restore intervertebral height of lumbar vertebra while maintaining the stability of lumbar vertebra and re-establishing motor function of lumbar space.

Investigating the species/biovars,distribution patterns,and genetic correlations of Brucella from sheep in north-west China is critical to reveal the population and epidemiological characteristics of the Brucella melitensis.In this study,con-ventional identification and AMOS-PCR were used to determine the species/biovars of Brucella isolated from 13 regions in northwest China.MLST and MLVA-16 genotyping methods were used to analyze the genetic characteristics of the strains.Con-ventional identification and AMOS-PCR detection revealed that 59 Brucella melitensis were isolated in this study,in-cluding 22 strains from Inner Mongolia,17 strains from Xin-jiang,13 strains from Gansu,and 7 strains from Qinghai,of which 58 strains were B.melitensis biovar 3,and one strain was B.melitensis biovar 1.MLST analysis indicated that 90％(53/59)of B.melitensis were of ST8 sequence type,the dominant epidemic population.The MLVA-11 survey demonstrated that 59 B.melitensis strains clustered into six MLVA-11 genotypes,and 87％of the strains were of MLVA-11 genotype 116.Therefore,the predominant strains in the northwest region were from the Eastern Mediterranean lineage.MLVA-16 divided 59 strains of B.melitensis into 40 gen-otypes,eight of which were shared genotypes.Each genotype was composed of two to seven strains from the same region,thereby indicating that the cases of each shared genotype were outbreaks from a common source of infection.All shared MLVA-16 genotypes comprised strains from the same province,thus indicating apparent regional clustering characteristics of strains in each province.In a genetic comparison between populations and isolated strains from the spleens of sheep,multiple identical MLVA-16 genotypes were found to be composed of strains from different hosts.These findings indicated a transmission path-way from sheep/goats to humans.B.melitensis biovar 3 was the main pathogen causing animal brucellosis in the northwest re-gion,and infected sheep were the main brucellosis infection source in the regional population.The ST8 strains were the domi-nant epidemic population,and the MLVA genotype of strains in each region showed clear regional clustering characteristics.

Bone development shows certain regularity with age. The regularity can be used to infer age and serve many fields such as justice, medicine, archaeology, etc. As a non-invasive evaluation method of the epiphyseal development stage, MRI is widely used in living age estimation. In recent years, the rapid development of machine learning has significantly improved the effectiveness and reliability of living age estimation, which is one of the main development directions of current research. This paper summarizes the analysis methods of age estimation by knee joint MRI, introduces the current research trends, and future application trend.
Epiphyses/diagnostic imaging* ; Age Determination by Skeleton/methods* ; Reproducibility of Results ; Magnetic Resonance Imaging/methods* ; Knee Joint/diagnostic imaging*