BACKGROUND:In orthodontic treatment,full-mouth treatment is usually used to treat single-root severely twisted teeth,and single-tooth treatment is less common.OBJECTIVE:To design a personalized orthodontic device based on biomechanical principles to address the rotation of teeth 11,12,13,21,22,and 23,and evaluate the device's impact on tooth movement using three-dimensional finite element method.METHODS:Based on the biomechanical principle of tooth rotation and movement,a personalized orthodontic device was made by digital design combined with three-dimensional printing,so that the personalized orthodontic device and the tooth formed an anchorage system.The absolute anchorage of the micro-implant was used to precisely control the single-root twisted tooth in the three-dimensional direction.The CBCT data of the maxillary alveolar bone and tooth tissue of a female volunteer were collected.The three-dimensional finite element models of the twisted tooth-periodontal ligament-maxillary bone-personalized orthodontic device were established using Mimics,Geomagic Wrap,SolidWorks,3-matic Research 15.0,and Ansys Workbench software.The equivalent stress distribution characteristics of the personalized orthodontic device,the movement trend of the tooth,and the equivalent stress distribution characteristics of the periodontal ligament were calculated under a thrust of 60 g.RESULTS AND CONCLUSION:(1)The maximum equivalent stress observed on the personalized orthodontic device was 47.71 MPa.(2)The initial tooth displacement under the device demonstrated a rotational trend.The peak equivalent stress in the periodontal ligament was concentrated at the neck,while lower stress was observed in the apex region.(3)The safety and feasibility of the personalized orthodontic device designed in this study for severely rotated single-rooted teeth were preliminarily verified through finite element analysis.

BACKGROUND:In orthodontic treatment,full-mouth treatment is usually used to treat single-root severely twisted teeth,and single-tooth treatment is less common.OBJECTIVE:To design a personalized orthodontic device based on biomechanical principles to address the rotation of teeth 11,12,13,21,22,and 23,and evaluate the device's impact on tooth movement using three-dimensional finite element method.METHODS:Based on the biomechanical principle of tooth rotation and movement,a personalized orthodontic device was made by digital design combined with three-dimensional printing,so that the personalized orthodontic device and the tooth formed an anchorage system.The absolute anchorage of the micro-implant was used to precisely control the single-root twisted tooth in the three-dimensional direction.The CBCT data of the maxillary alveolar bone and tooth tissue of a female volunteer were collected.The three-dimensional finite element models of the twisted tooth-periodontal ligament-maxillary bone-personalized orthodontic device were established using Mimics,Geomagic Wrap,SolidWorks,3-matic Research 15.0,and Ansys Workbench software.The equivalent stress distribution characteristics of the personalized orthodontic device,the movement trend of the tooth,and the equivalent stress distribution characteristics of the periodontal ligament were calculated under a thrust of 60 g.RESULTS AND CONCLUSION:(1)The maximum equivalent stress observed on the personalized orthodontic device was 47.71 MPa.(2)The initial tooth displacement under the device demonstrated a rotational trend.The peak equivalent stress in the periodontal ligament was concentrated at the neck,while lower stress was observed in the apex region.(3)The safety and feasibility of the personalized orthodontic device designed in this study for severely rotated single-rooted teeth were preliminarily verified through finite element analysis.

Objective:To apply mass spectrometry as well as bioinformatics techniques to analyze HBV peptides derived from Pol and X proteins presented by human immortalized B lymphocytes(BLCLs),and to screen for effective T-cell epitopes,which lays the foundation for the development of therapeutic vaccines.Methods:The group has constructed a genome-wide expression plasmid containing 1.2-fold HBVC2 isoforms and transfected it into BLCLs by electro-transfection,isolated and identified HBV peptides by LC-MS/MS,bioinformatically predicted peptide sequences in terms of sensitization,antigenicity,toxicity,HLA molecular affinity,and the ability of peptide HLA-class Ⅰ complex to bind to specific T cells,and retrieved reported sequences.Results:HBV peptides from lysates of five immortalized B cells(BLCLs-1 to BLCLs-5)carrying HBVC2 subtype-expressing recombinants were analyzed,and 141 peptides with sequence lengths of no less than 8 amino acid residues(≥8 aa)were successfully isolated and identified,of which 133 were derived from Pol,and 8 from X proteins.The 141 HBV peptides were analyzed for sensitization,antigenicity and toxicity,and 50 antigenic,non-toxic and sensitizing HBV peptides(47 from Pol and 3 from X protein)were screened for affinity analysis with HLA-class Ⅰ and Ⅱ molecules and for prediction of the binding ability of the peptide HLA-class Ⅰ complexes to specific T cells.Among these peptides,37 had affinity to the corresponding genotypes of HLA-class Ⅰ and Ⅱ molecules.Finally,we obtained 37 peptides with antigenic,nontoxic,and sensitizing properties with IC50<500 nmol/L to HLA-class Ⅰ and Ⅱ molecules,which have affinitied to the corresponding genotypes but have not been reported,and can be continued to be explored as potential epitopes.Finally,15 HBV peptide hotspot core regions were formed by intra-and inter-strain common,contained,overlapping or neighboring sequence analysis of 141 peptides,with 7 core region sequences with antigenic,nontoxic,and sensitizing properties restricted to the corresponding geno-types.Peptides with affinity IC50<500 nmol/L had an affinity core sequence overlap of no less than 8 amino acids,and can be priori-tized for candidate T cell epitopes for subsequent studies.Conclusion:Peptides derived from Pol and X proteins have been successfully isolated and identified,and potential T cell epitopes have been screened.

Objective:Constructing a risk prediction model to assess the impact of various factors on the need for auxiliary bone grafting with implant placement following alveolar ridge preservation (ARP) in posterior teeth.Methods:According to the sample size calculation formula, the sample size was calculated using the pmsampsize package of R 4.1.3 software, based on inclusion and exclusion criteria, a total of 110 posterior teeth in 98 patients who underwent ARP at the Department of Periodontology, School and Hospital of Stomatology, China Medical University, from January 2018 to May 2024 were conducted. Teeth were randomly divided into modeling group and validation group with 7∶3 ratio according to the random number table. The modeling group was divided into direct implantation group and auxiliary bone grafting group on the basis of whether auxiliary bone grafting was performed 6 months after ARP. Univariate and multivariate analyses were conducted to identify factors influencing auxiliary bone grafting with implant placement following ARP. Nomogram was constructed using R software. Receiver operator characteristic (ROC) curve and calibration curve were drawn to evaluate model differentiation and consistency. The decision curve analysis (DCA) was used to assess the clinical application value of the model.Results:Age ( OR=1.06, P=0.001), maximum attachment loss (AL) ( OR=1.75, P<0.001), reason of tooth extraction ( OR=12.73, P<0.001), smoking [<10 cigarettes/d ( OR=7.59, P<0.001);≥10 cigarettes/d ( OR=28.12, P<0.001)] and stage of periodontitis [stage Ⅱ ( OR=2.57, P=0.430); stage Ⅲ ( OR=21.00, P=0.007); stage Ⅳ ( OR=76.50, P<0.001)] influenced the necessity for auxiliary bone grafting with implant placement after ARP. After multivariate analysis of the above influencing factors, it was found that smoking [<10 cigarettes/d ( OR=7.02, P=0.009);≥10 cigarettes/d ( OR=10.27, P=0.026)] was an independent risk factor for the need of auxiliary bone grafting with implant placement after ARP. The area under the ROC curve for internal verification was 0.90 (95 %CI: 0.84-0.97), and the H-L goodness of fit test results were χ 2=4.79, P=0.780, indicating a good agreement. The area under the externally verified ROC curve was 0.97 (95 %CI: 0.92-1.00), suggesting that the fitting effect was slightly lower than that of the modeling group, and the predicted value of the model was slightly lower than the true value, which might underestimate the risk of additional surgery in patients. Results:of H-L goodness of fit test were χ 2=5.03, P=0.754. The DCA curve showed that when the probability of high-risk threshold was between 0.06 and 0.93, the clinical application value of the prediction model was higher. Conclusions:Age, smoking, reason of tooth extraction, stage of periodontitis, and maximum AL of the affected teeth were related to the necessity for auxiliary bone grafting with implant placement 6 months after ARP. Smoking was an independent risk factor for auxiliary bone grafting surgery. The constructed nomogram model had good discrimination and consistency.

Objective:To evaluate the role of fibrinogen in perioperative neurocognitive disorder (PND) in aged mice.Methods:Sixty SPF healthy male C57BL/6J mice, aged 16-18 months, weighing 25-30 g, were divided into 4 groups ( n=15 each) using a random number table method: control group (group C), PND group (group P), urokinase group (group U) and PND+ urokinase group (group PU). Abdominal surgery was performed under 3% sevoflurane anesthesia to establish the mouse model of PND. In PU group, urokinase 20 000 U/kg was intraperitoneally administered at 1 h after surgery, once a day, for 5 consecutive days. In group U, urokinase was intraperitoneally injected once a day for 5 consecutive days without anesthesia and surgery. The cognitive function was assessed after operation using the novel object recognition test (discrimination index) and the Morris water maze test (frequency of crossing the original platform and percentage of the time spent in the target quadrant). The expression of occludin, claudin-5, fibrinogen and ionized calcium-binding adapter molecule 1 (Iba-1) and CD11b in hippocampal tissues was detected using Western blot, the area of fibrinogen extravascular deposits was measured and the morphology of microglia was observed using the immunofluorescence staining, and the mRNA expression of pro-inflammatory factors (interleukin-1beta, tumor necrosis factor-alpha, and inducible nitric oxide synthase), anti-inflammatory factors (interleukin-4 and arginase-1), and chemokines (chemokine 2 and chemokine ligand 10) in hippocampal tissues was detected by quantitative real-time polymerase chain reaction after surgery. Results:Compared with group C, the parameters of cognitive function were significantly decreased, the expression of occludin and claudin-5 was down-regulated, the expression of fibrinogen was up-regulated, the area of fibrinogen extravascular deposits was increased, the number of branches was decreased and the average process length was shortened in the microglia around fibrinogen deposits, the expression of Iba-1 and CD11b was up-regulated, the mRNA expression of proinflammatory cytokines and chemokines was up-regulated, and the mRNA expression of the anti-inflammatory factors was down-regulated in group PND ( P<0.05). Compared with group PND, the parameters of cognitive function were significantly increased, the expression of occludin and claudin-5 was up-regulated, the expression of fibrinogen was down-regulated, the area of fibrinogen extravascular deposits was decreased, the number of branches was increased and the average process length was prolonged in the microglia around fibrinogen deposits, the expression of Iba-1 and CD11b was down-regulated, the mRNA expression of proinflammatory cytokines and chemokines was down-regulated, and the mRNA expression of the anti-inflammatory factors was up-regulated in group PU ( P<0.05). Conclusions:Fibrinogen deposits in the brain parenchyma through the damaged blood-brain barrier after anesthesia and surgery and participates in the development of PND, and the underlying mechanism may be related to the promotion of microglial activation and the induction of neuroinflammation in aged mice.

Objective:To evaluate the relationship between the mechanism of ω-3 polyunsaturated fatty acids (ω-3 PUFAs) preventing sevoflurane-induced neurotoxicity and phosphorylated Tau glymphatic system clearance pathway in neonatal mice.Methods:Eighteen C57BL/6 pregnant mice were used in this study and subjected to 2 feeding regiments using the random number table method. Twelve mice were selected to receive a standard diet, and 6 mice were selected to receive a diet supplemented with fish oil (ω-3 polyunsaturated fatty acids [300 mg was added to every 20 g of standard diet from the 2nd day of gestation to 14 days after parturition). The healthy neonatal mice of both sexes, aged 6 days, weighing 3-5 g, were selected after parturition. Forty-eight neonatal pups from 6 pregnant mice that were fed a standard diet were assigned to control group (C group), 48 neonatal pups from 6 pregnant mice that were fed a standard diet were assigned to sevoflurane group (S group), and 48 neonatal pups from pregnant mice that were fed a diet supplemented with fish oil were assigned to ω-3 PUFAs plus sevoflurane group (PS group) using the random number table method. All the offspring mice in all groups were breastfed until 21 days of birth and then were housed in separate cages from their mothers after 21 days of birth and provided with ad libitum access to standard food. S group and PS group inhaled 3% sevoflurane and 40% oxygen for 2 h daily on postnatal days 6, 7 and 8. C group inhaled only 40% oxygen at the same flow rate. Y maze test was performed at postnatal day 33 to assess the spatial memory and cognitive function. The rotarod test was performed at postnatal day 35 to assess the fine motor coordination. The influx and efflux functions of the glymphatic system were assessed through intracisternal tracer infusion with the fluorescent tracer at postnatal days 14 and 35. The influx function was evaluated by the percentage of the area of tracer penetration 30 min after injection, while the efflux function was determined by the percentage of the residual area of the tracer 90 min after injection. The mice were sacrificed and the hippocampal tissue was obtained at postnatal day 14 for determination of the expression of phosphorylated Tau protein at serine 202 site and threonine 205 site (Tau-PS202/PT205) and total Tau protein by Western blot. The cerebrospinal fluid (CSF) was collected at postnatal day 14 for determination of the concentration of phosphorylated Tau protein by enzyme-linked immunosorbent assay. The mice were sacrificed and the hippocampal tissue was obtained at postnatal day 35 for determination of the expression of caspase-3, caspase-9 and cytochrome C (Cyt c) (by Western blot) and the apoptosis rate of neurons (by TUNEL).Results:Compared with C group, the time of staying at the new arm and in the rotarod test was significantly shortened, the percentage of new arm movement distance was decreased, the percentage of tracer penetration area was decreased at postnatal day 14, the percentage of residual tracer area was increased at postnatal day 14, the expression of Tau-PS202/PT205 in the hippocampus was up-regulated at postnatal day 14, the concentration of phosphorylated Tau protein in CSF was reduced at postnatal day 14, the apoptosis rate of hippocampal neurons was increased at postnatal day 35 ( P<0.05), and the expression of caspase-3, caspase-9 and Cyt c in the hippocampus was up-regulated at postnatal day 35 in S group ( P<0.05). Compared with S group, the time of staying at the new arm and in the rotarod test was significantly prolonged, the percentage of new arm movement distance was increased, the percentage of tracer penetration area was increased at postnatal day 14, the percentage of residual tracer area was decreased at postnatal day 14, the expression of Tau-PS202/PT205 in the hippocampus was down-regulated at postnatal day 14, the concentration of phosphorylated Tau protein in CSF was increased at postnatal day 14, the apoptosis rate of hippocampal neurons was decreased at postnatal day 35, and the expression of caspase-3, caspase-9 and Cyt c in the hippocampus was down-regulated at postnatal day 35 in PS group ( P<0.05). Conclusions:The mechanism by which ω-3 PUFAs prevents cerebral neurotoxicity induced by repeated neonatal sevofurane exposure may be related to the enhancement of phosphorylated Tau protein clearance via the glymphatic system.

Objective:To evaluate the relationship between the mechanism of ω-3 polyunsaturated fatty acids (ω-3 PUFAs) in preventing brain neurotoxicity caused by multiple sevoflurane anesthesia and peroxisome proliferator-activated receptor gamma (PPARγ)/peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) signaling pathway in neonatal mice.Methods:This study was performed in 2 parts. Part Ⅰ Using a random number table method, 6 C57BL/6 pregnant mice were assigned to receive a standard diet, 3 pregnant mice were assigned to receive a diet supplemented with fish oil from day 2 of gestation to day 14 after parturition (ω-3 PUFAs 300 mg were added to every 20 g of conventional diet). Healthy C57BL/6 mice of both sexes, aged 6 days, weighing 3-5 g, were selected after parturition. Seventeen neonatal pups from 3 pregnant mice that were fed a conventional diet were assigned to control group (C group), 17 neonatal pups from 3 pregnant mice that were fed a conventional diet were assigned to sevoflurane group (S group), and 17 neonatal pups from pregnant mice that were fed a diet supplemented with fish oil were assigned to ω-3 PUFAs plus sevoflurane group (PS1 group) using the random number table method. Part Ⅱ Four C57BL/6 pregnant mice were assigned to receive a diet supplemented with fish oil from day 2 of gestation to day 14 after parturition. After parturition, 12 neonatal pups from 2 pregnant mice that were fed a diet supplemented with fish oil were assigned to ω-3 PUFAs plus sevoflurane group (PS2 group), and 12 neonatal pups from 2 pregnant mice that were fed a diet supplemented with fish oil were assigned to ω-3 PUFAs plus PPARγ inhibitor GW9662 plus sevoflurane group (PGS group) using a random number table method. GW9662 (2 mg/kg) was intraperitoneally injected at 30 min before exposure to sevoflurane in PGS group. All offspring mice were breastfed until 21 days of age, after which they were housed separately from the mother and allowed ad libitum access to a conventional diet. S, PS1, PS2 and PGS groups inhaled 3% sevoflurane in 40% oxygen for 2 h daily on postnatal days 6, 7 and 8. C group inhaled only 40% oxygen instead. Y maze test was performed on days 33 after birth. The rotarod test was performed on day 35 after birth. After the behavioral testing, the expression of PPARγ, PGC1α, mitofusin-1 (MFN1), MFN2, dynamin-related protein 1 (DRP1), interleukin-6 (IL-6), interleukin-1 β (IL-1 β), and tumor necrosis factor-α (TNF-α) was detected by Western blot, the ultrastructure of mitochondria in hippocampal neurons was observed with a transmission electron microscope, and the mitochondrial membrane potential (MMP), level of reactive oxygen species (ROS) and content of ATP were determined.Results:Part Ⅰ Compared with C group, the time of stay at the new-arm and time spent on the rotarod were significantly shortened, the percentage of movement distance in the new-arm was decreased, the expression of PPARγ, PGC1α, MFN1 and MFN2 in the hippocampus was down-regulated, the expression of DRP1, IL-6, IL-1β and TNF-α in the hippocampus was up-regulated, the MMP and content of ATP were decreased, and the level of ROS was increased in S group ( P<0.05). Compared with S group, the time of stay at the new-arm and time spent on the rotarod were significantly prolonged, the percentage of movement distance in the new-arm was increased, the expression of PPARγ, PGC1α, MFN1 and MFN2 in the hippocampus was up-regulated, the expression of DRP1, IL-6, IL-1β and TNF-α in the hippocampus was down-regulated, the MMP and content of ATP were increased, and the level of ROS was decreased in PS1 group ( P<0.05). Part Ⅱ Compared with PS2 group, the time of stay at the new-arm and time spent on the rotarod were significantly shortened, the percentage of movement distance in the new-arm was decreased, the MMP and content of ATP were decreased, the level of ROS was increased, and the expression of IL-6, IL-1β and TNF-α was up-regulated ( P<0.05). Conclusions:The mechanism by which ω-3 PUFAs prevent brain neurotoxicity caused by multiple sevoflurane anesthesia is related to the activation of the PPARγ/PGC1α signaling pathway and alleviation of mitochondrial dysfunction and neuroinflammation in neonatal mice.

Objective:To evaluate the role of docosahexaenoic acid (DHA) in long-term cognitive impairment after multiple sevoflurane anesthesia in newborn mice.Methods:Clean-grade healthy male C57BL/6 mice, aged 6 days, were used in this study. Ten mice were divided into 2 groups ( n=5 each) by the random number table method: control group (group C) and sevoflurane group (group S). The animals inhaled 3% sevoflurane for 2 h at 6, 7 and 8 days after birth. The DHA content was detected by ultra-high performance liquid chromatography-mass spectrometry at 9 days of age. Fifty-two mice were selected and divided into 4 groups ( n=13 each) by a random number table method: control+ normal saline group (group C+ S), sevoflurane anesthesia + normal saline group (group S+ S), control+ DHA group (group C+ D), and sevoflurane anesthesia+ DHA group (group S+ D). The sevoflurane anesthesia method was the same as the one mentioned above. DHA 50 mg/kg was administered by intragastric gavage from postnatal days 6-19 (at 6, 7 and 8 days after birth, 2 h before anesthesia) in C+ D and S+ D groups. The equal volume of normal saline was given instead in C+ S group and S+ S group. The novel object recognition test was conducted at 37 days of age, and the Morris water maze test was performed at 42 days of age. The corpus callosum and hippocampal tissues were isolated at 47 days of age for examination of the ultrastructure of myelin (with a transmission electron microscope) and for determination of the expression of myelin basic protein (MBP) in hippocampal tissues (by Western blot). The G-ratio was calculated. Results:Compared with group C, the content of DHA in hippocampal tissues was significantly decreased in group S ( P<0.05). Compared with group C+ S, the discrimination index was significantly decreased, the percentage of duration of staying at the target platform quadrant and the number of crossing the original platform were decreased, the expression of MBP was down-regulated, and the G-ratio in the original platform and hippocampus was increased in S+ S group ( P<0.05). Compared with group S+ S, the discrimination index was significantly increased, the percentage of duration of staying at the target platform quadrant and the number of crossing the original platform were increased, the expression of MBP was up-regulated, and the G-ratio in the original platform and hippocampus was decreased in S+ D group ( P<0.05). Conclusions:The mechanism of long-term cognitive impairment following multiple sevoflurane anesthesia may be related to a decrease in the content of DHA, which subsequently leads to myelin structural damage in neonatal mice.

The spread of antibiotic resistance genes(ARGs)poses a serious threat to global public health.Recent studies have shown that in addition to the difficulty in antibiotic selection,many non-anti-biotic environmental pollutants,such as microplastics,heavy metals,nanomaterials and non-antibiotic drugs,can accelerate the spread of ARGs.This paper begins by outlining the influence of non-antibiotic environmental pollutants on the conjugative transfer of ARGs.Then,the mechanisms of ARGs are analyzed from the perspective of molecular biology,which include inducing the generation of large amounts of reactive oxygen radicals,triggering cellular oxidative stress,increasing intercellular contact,altering the permeability of cell membranes,affecting energy metabolism,triggering group sensing effects,and regulating the expression of genes related to the transfer of ARGs.Finally,the limitations of current studies are presented,and tips are given about future research.In conclusion,the effects of non-antibi-otic environmental pollutants on the spread and dispersal of ARGs need to be studied more extensively.

Objective:To evaluate the effect of multiple sevoflurane anesthesia on the metabolism of long-chain fatty acids in the hippocampus of newborn mice and the role of peroxisome proliferator-activated receptor-beta (PPARβ).Methods:Clean-grade healthy male C57BL/6 mice, aged 6 days, weighing 3-5 g, were divided into 2 groups ( n=8 each) by a random number table method: control group (group C) and multiple sevoflurane anesthesia group (group S). This study was performed in 2 parts. PartⅠ Sixteen newborn mice were divided into 2 groups ( n=8 each) using a random number table: control group (C group) and multiple sevoflurane anesthesia group (S group). Anesthesia was performed with sevoflurane on postnatal days 6, 7 and 8. The hippocampus was obtained at postnatal day 9 for determination of the content of long-chain fatty acids (by ultra-high performance liquid mass spectrometry), expression of PPARβ (by Western blot), and expression of stearoyl-CoA desaturase-2 (Scd2) and fatty acid desaturase 2 (Fads2) mRNA (using quantitative real-time polymerase chain reaction). Part Ⅱ Twenty-one newborn mice were divided into 3 groups ( n=7 each) using a random number table: control+ normal saline group (group C+ S), sevoflurane + normal saline group (group S+ S), and sevoflurane+ PPARβ specific agonist KD3010 group (group S+ K). Anesthesia was carried out with sevoflurane on postnatal days 6, 7 and 8. KD3010 25 mg/kg was intraperitoneally injected once a day from postnatal day 6 to 13 in S+ K group. The novel object recognition test was performed on postnatal day 37, and the Morris water maze test was performed on postnatal day 42. The hippocampal tissues were obtained on postnatal day 47 for detection of the expression of Scd2 mRNA and Fads2 mRNA by fluorescent quantitative real-time polymerase chain reaction. Anesthesia was carried out with sevoflurane as follows: Mice were exposed to 3% sevoflurane in 40% oxygen-60% nitrogen in an induction chamber for 2 h at a flow rate of 1 L/min. Results:PartⅠ Compared with group C, the total content of long-chain fatty acids, contents of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids were significantly decreased, the percentage of saturated fatty acids was increased, the percentage of monounsaturated fatty acids and polyunsaturated fatty acids was decreased, the expression of Scd2 mRNA and Fads2 mRNA was down-regulated, and the expression of PPARβ was down-regulated in group S ( P<0.05). Part Ⅱ Compared with group C+ S, the discrimination index in the novel object recognition test and percentage of time spent in the target quadrant were significantly decreased, the number of crossing the original platform was reduced, and the expression of Scd2 and Fads2 mRNA was down-regulated in group S+ S ( P<0.05). Compared with group S+ S, the discrimination index in the novel object recognition test and percentage of time spent in the target quadrant were significantly increased, the number of crossing the original platform was increased, and the expression of Scd2 and Fads2 mRNA was up-regulated in group S+ K ( P<0.05). Conclusions:Multiple anesthesia with sevoflurane can lead to the disorder of long-chain fatty acid metabolism in the hippocampus of neonatal mice, resulting in long-term cognitive dysfunction. The mechanism may be related to inhibiting the activity of hippocampal PPARβ signaling pathway.