Motion sickness refers to a multi-system physiological syndrome caused by abnormal acceleration and motion vision scene immersion.It occurs commonly in transportation,military operations,space exploration and other fields.This article reviews recent advances in mechanism,prediction and assessment as well as control measures for motion sickness,and discusses possible research direction of motion sickness in the future.The biological basis for motion sickness sensory conflict theory has been expanded;genomic sequencing and artificial intelligence techniques have been used as novel tools for motion sickness prediction and evaluation.Acclimatization training,anti-motion sickness medication and non-drug symptom control measures used in combination is the key for motion sickness prevention and treatment.

Objective To observe the changes of plasma gastrointestinal hormones in motion sickness sensitive and insensitive individuals before and after vertical oscillation stimulation,and to construct a susceptibility prediction model for motion sickness.Methods A total of 60 healthy male volunteers were enrolled to receive sinusoidal vertical oscillation stimulation for 45 min.The motion sickness susceptibility questionnaire(MSSQ)was filled out before the experiment.Immediately after motion,the severity of motion sickness was evaluated by Graybiel scale.The motion sickness sensitive(Graybiel score≥8 and MSSQ susceptibility index＞21,n=15)and insensitive(Graybiel score≤2 and MSSQ susceptibility index＜5,n=15)participants were screened.Plasma levels of glucagon-like peptide-1(GLP-1),cholecystokinin(CCK),leptin,ghrelin,neuropeptide Y(NPY)and orexin A(OXA)were detected by enzyme-linked immunosorbent assay before and after vertical oscillation stimulation.Logistic regression model was used to analyze the predictive effect of plasma gastrointestinal hormone levels on susceptibility to motion sickness,and a combined predictive model was established.Receiver operating characteristic(ROC)curve was used to analyze predictive value of the model.Results Ghrelin and CCK levels were significantly increased in the sensitive group after stimulation compared with those before stimulation(both P＜0.01),while NPY and leptin levels were significantly decreased(both P＜0.01).Similar results were also observed when compared with the insensitive group after stimulation.Multivariate logistic regression analysis showed that plasma ghrelin,CCK and NPY were independent predictors of susceptibility to motion sickness.The established susceptibility prediction model for motion sickness was logit(P)=-0.051 ×ghrelin+0.060× NPY-0.169 ×CCK+33.397.ROC curve analysis showed that area under curve(AUC)value of the prediction model was 0.988,the sensitivity and specificity were 100.0％and 93.3％,respectively,and the prediction effect was better than ghrelin,CCK and NPY alone(AUC=0.792,0.880,0.838).Conclusion The changes of peripheral gastrointestinal appetite regulating hormone levels may be related to the susceptibility to motion sickness.The combined use of these indicators can predict the susceptibility to motion sickness.

Objective To explore the improving effects of motion sickness acclimatization training methods,namely sinusoidal vertical oscillation stimulation and sinusoidal vertical oscillation stimulation combined with visual virtual reality(VR)swell stimulation,on cognitive performance of individuals with extremely severe motion sickness.Methods A total of 90 individuals with extremely severe motion sickness screened by the Graybiel score during 6 h navigation were randomly divided into vertical group,vertical+VR group,and control group(n=30).The abilities of vigilance,memory,rapid calculation,information processing and visual manipulation were evaluated before and after the acclimatization training using a self-developed cognitive performance evaluation software.Results On the 1st day of training,the numbers of missed targets of the vertical group and vertical+VR group were increased in the vigilance test;the reaction time was prolonged in the short-term memory,rapid calculation,information processing and visual manipulation tasks;and the efficiency of rapid calculation was reduced.After acclimatization training,the numbers of missed targets were reduced to the baseline level in the vertical and vertical+VR groups,and the reaction time in the short-term memory,rapid calculation,information processing and visual manipulation tasks and the efficiency of rapid calculation were improved.Conclusion Motion sickness caused by vertical oscillation stimulation or vertical oscillation combined with visual VR swell stimulation can decrease vigilance,short-term memory,rapid calculation,information processing and visual manipulation abilities.Motion sickness acclimatization training can significantly improve the above cognitive abilities.

Objective To study the acclimatization time and effects for preventing motion sickness under sinusoidal vertical oscillation stimulation,visual virtual reality(VR)swell stimulation,and their combined stimulation.Methods Totally 120 individuals with extremely severe motion sickness during 6 h navigation were randomly divided into 4 groups(n=30):vertical group,VR group,vertical+VR group,and control group.The severity of symptoms during the training period was assessed daily by Graybiel scale,and the number of drops from flexible treadmill in the VR group was recorded.The Graybiel score of 0 for 3 d and/or the number of drops for 0 were considered as complete acclimatization.The training effect was validated by navigation under more severe sea conditions.Results The Graybiel scores of the vertical group and vertical+VR group,as well as the number of drops of the VR group were decreased with the increase of training days,and reached the acclimatization level on the 3rd,5th,and 2nd training day,respectively.The longest acclimatization time in the vertical,vertical+VR,and VR groups was 8,8,and 5 d,with an average acclimatization time of 3.6,3.9,and 2.7 d,respectively;the acclimatization rates within 5 d were 93.33％(28/30),76.67％(23/30),and 100.00％(30/30),respectively;the proportions of individuals with effective acclimatization training in the verification voyage were 86.67％(26/30),96.67％(29/30),and 66.67％(20/30),respectively;and the training efficiency was 85.19％,96.30％,and 62.97％,respectively.Conclusion Three training methods all have effects on motion sickness acclimatization,and the acclimatization period is 5-8 d.The acclimatization effects of the vertical oscillation and vertical oscillation+VR training are better than the VR training.

Objective To observe the effect of the supine-posture ripple wood training in preventing motion sickness caused by linear acceleration.Methods Totally 61 motion sickness sensitive males were screened by a vertical oscillation simulator and divided into mildly sensitive group(Graybiel score 1-15,n=28)and severely sensitive group(Graybiel score 16,n=33).The participants in the 2 groups received 5-d ripple wood training,30 min/d.The movement frequency of the ripper wood was maintained at 0.25-0.35 Hz,with an acceleration of 0.15-0.25 g.Graybiel score during the training period was recorded.The static balance function test was conducted before and after training on the 1st and 5th day.Results During the training period,the Graybiel scores and motion sickness incidence in the severely sensitive group were decreased with the increase of training days,and all participants achieved complete acclimatization on the 4th day.The Graybiel scores of the mildly sensitive group were low during the whole period,and the complete acclimatization period was 2 d.There was no significant difference in the sway area of the severely sensitive group in static balance function test before and after training(P＞0.05).The mean velocity of the severely sensitive group in static balance function test was significantly increased after training versus before training on the 1st day(P＜0.01),and there was no significant difference before and after training on the 5th day(P＞0.05).There were no significant differences in the sway area or mean velocity of the mildly sensitive group during the whole training period(all P＞0.05).The validation experiment showed that the motion sickness incidence and the symptom severity were significantly decreased in both groups;the motion sickness incidence of the mildly sensitive group decreased from 100.00％(28/28)to 35.71％(10/28);the incidence of severe symptoms in the severely sensitive group decreased from 100.00％(33/33)to 6.06％(2/33)and the vomiting incidence decreased from 96.97％(32/33)to 6.06％(2/33).Conclusion The supine-posture ripple wood training has great effect in preventing motion sickness,with widespread use and simple operation.

Objective To observe the distribution characteristics of motion sickness susceptibility and compare the efficacy of modified motion sickness susceptibility questionnaire(MSSQ),motion sickness history questionnaire and Graybiel scale in evaluating motion sickness.Methods The susceptibility to motion sickness and historical symptoms were investigated using MSSQ and motion sickness history questionnaire among 1 661 males in navy units A,B,and C.A total of 389 people from the unit C were selected for simulating vertical oscillation stimulation,and the severity of motion sickness was evaluated by Graybiel scale during the stimulation process.The evaluation efficacy of MSSQ,motion sickness history questionnaire and Graybiel scale for motion sickness was analyzed by receiver operating characteristic(ROC)curves.Results The overall distribution of motion sickness susceptibility assessed by MSSQ and motion sickness history questionnaire in this population was right skewed.The distribution characteristics in the units A,B,and C were consistent with the overall distribution,and there was no significant difference among the 3 units.A positive correlation was observed between the MSSQ and the motion sickness history questionnaire in the units A,B,and C(rs=0.565,0.565,0.554),and both of them were comparable in assessing the incidence of motion sickness and severe motion sickness.However,the incidence of motion sickness assessed by Graybiel scale was significantly lower than that assessed by MSSQ and motion sickness history questionnaire(both P＜0.05),and the incidence of severe motion sickness was significantly higher than that assessed by MSSQ and motion sickness history questionnaire(both P＜0.05).ROC curve analysis showed that MSSQ had good predictive value for motion sickness susceptibility and severe motion sickness(area under curve[AUC]=0.736,0.750),while the Graybiel scale had poor predictive ability(AUC=0.559,0.557).Conclusion The right skewed distribution of susceptibility to motion sickness is preliminarily determined.During the acclimatization training for motion sickness,the susceptible individuals can be screened by MSSQ and then subjected to vertical oscillation stimulation to improve the training efficiency.

Objective To investigate whether prophylactic anticoagulation therapy can reduce the risk of postoperative complications in patients with primary liver cancer(PLC)after hepatectomy,and to explore the influencing factors of postoperative complications.Methods The clinical data of 495 patients undergoing hepatectomy for PLC in The Third Affiliated Hospital of Naval Medical University(Second Military Medical University)from Feb.2019 to May 2021 were collected.The patients were divided into anticoagulation group(n=287,receiving prophylactic low-molecular-weight heparin after surgery)and conventional treatment group(n=208).The postoperative complications were compared between the 2 groups,and the influencing factors were analyzed using logistic regression model.Results The postoperative overall complication incidence of the 495 patients after hepatectomy was 30.7％(152/495),ranking as infection(9.1％,45/495),acute respiratory distress syndrome(ARDS;6.5％,32/495),bleeding(6.3％,31/495),post-hepatectomy liver failure(PHLF;6.1％,30/495),and venous thromboembolism(VTE;2.8％,14/495).The incidence rates of postoperative VTE,ARDS,and PHLF were significantly lower in the anticoagulation group than those in the conventional treatment group(1.4％[4/287]vs 4.8％[10/208],3.8％[11/287]vs 10.1％[21/208],and 3.8％[11/287]vs 9.1％[19/208];all P＜0.05),but there was no significant difference in the incidence of postoperative bleeding between the 2 groups(P＞0.05).Multivariate logistic regression analysis showed that age,portal hypertension,and tumor number were independent risk factors for postoperative VTE;portal hypertension,intraoperative blood loss,intraoperative blood transfusion,and preoperative procalcitonin(PCT)were independent risk factors for PHLF;ascites and preoperative bilirubin were independent risk factors for ARDS;and postoperative prophylactic anticoagulation was an independent protective factor for VTE and ARDS(all P＜0.05).Conclusion Prophylactic anticoagulation can reduce the risks of VTE,PHLF,and ARDS in PLC patients after hepatectomy,without increasing the risk of postoperative bleeding.Age,portal hypertension,number of tumors,intraoperative blood loss,intraoperative blood transfusion,ascites,preoperative PCT,and preoperative bilirubin are risk factors for postoperative complications of PLC patients after hepatectomy.

Objective To explore the correlations between triglyceride glucose index(TyG)and its derivatives TyG-body mass index(BMI)and TyG-alanine transaminase(ALT)with the risk of lean metabolic associated fatty liver disease(MAFLD).Methods A total of 207 patients diagnosed with lean MAFLD and 100 lean healthy controls who received annual health examination in Health Management Center of our hospital from Jul.to Dec.2023 were enrolled.Plasma lipids,blood glucose,liver function,TyG,TyG-BMI and TyG-ALT were compared between the 2 groups.The influencing factors of lean MAFLD were analyzed by univariate and multivariate logistic regression models.All subjects were divided into 4 subgroups(Q1-Q4)according to the quartile of TyG and its derivatives,and the prevalence of lean MAFLD in each subgroup was observed.The receiver operating characteristic(ROC)curves of TyG,TyG-BMI and TyG-ALT for lean MAFLD were plotted to evaluate the prediction efficiency.Results Of the 8 764 health examination cases included,2 350(26.8％)had MAFLD,of which 207 were lean MAFLD(8.8％,207/2 350).Compared with the lean healthy controls,the patients in the lean MAFLD group were older,with more male and high BMI,and their fasting blood glucose,total cholesterol,triglyceride,low density lipoprotein-cholesterol,ALT,aspartate transaminase,γ-glutamyl transpeptidase,alkaline phosphatase,total bilirubin,TyG,TyG-BMI and TyG-ALT were significantly increased,while high density lipoprotein-cholesterol was significantly decreased(all P＜0.01).Logistic regression analysis showed that age,male,and elevated ALT level were independent risk factors for lean MAFLD.The prevalence of lean MAFLD in the Q4 subgroup of TyG was significantly higher than that in the Q1 and Q2 subgroups(34.3％[71/207]vs 10.6％[22/207]and 24.2％[50/207],both P＜0.05).The prevalence rates of lean MAFLD in the Q4 subgroup of TyG-BMI and the Q4 subgroup of TyG-ALT were significantly higher than those in the corresponding Q1,Q2,and Q3 subgroups(35.3％[73/207]vs 8.2％[17/207],24.6％[51/207],and 31.9％[66/207];33.8％[70/207]vs 14.0％[29/207],23.2％[48/207],and 29.0％[60/207];all P＜0.05).The area under curve(AUC)of TyG-BMI in predicting lean MAFLD was 0.869 0(95％confidence interval[CI]0.825 5-0.912 6,P＜0.001),which was higher than that of TyG(AUC=0.818 8[95％CI 0.768 0-0.869 6,P＜0.001])and TyG-ALT(AUC=0.772 5[95％CI 0.718 7-0.826 2,P＜0.001]).Conclusion TyG,TyG-BMI,and TyG-ALT are associated with lean MAFLD,and have predictive value for lean MAFLD.TyG and its derivatives are easy to calculate and cheap,and can be used for preliminary clinical assessment of lean MAFLD.

Objective To explore a method to improve the accuracy and generalization ability of medical diagnostic neural network models under conditions of small data volumes,and to address the issue of poor neural network model performance in computer-aided diagnosis of nail diseases due to limited training data.Methods A dual-model strategy integrating instance segmentation with fine-grained feature classification was proposed.The neural network model based on dual-model strategy was trained using the dataset of Image-Based Intelligent Diagnosis of Nail Disease Model task of the first National Digital Health Innovation Application Competition & Health and Medical Big Data Theme Competition.This dataset covered 8 types of nail diseases,including nail matrix nevi,paronychia,nail psoriasis,onychomycosis,subungual hemorrhage,melanonychia,periungual warts,and nail melanoma,with class imbalance present.The diagnostic performance of the dual-model strategy was evaluated and compared with single-model strategies(image classification models[ResNet50 and Swin Transformer]and target detection model based on faster region-based convolutional neural network[Faster R-CNN])under the same hardware and software training conditions.Results The dataset included 1 048 samples,including 210 cases of nail matrix nevi,186 cases of paronychia,69 cases of nail psoriasis,203 cases of onychomycosis,149 cases of subungual hemorrhage,71 cases of melanonychia,93 cases of periungual warts,and 67 cases of nail melanoma,with 90％used for training various models and 10％for evaluation.The micro F1 score was 0.324 in the image classification model based on ResNet50,0.381 in the image classification model based on Swin Transformer,0.572 in the target detection model based on Faster R-CNN,and 0.714 in the dual-model strategy model Mask R-CNN+Swin Transformer.The accuracy rates for diagnosing different nail diseases in the dual-model strategy were:nail matrix nevi 80.95％(17/21),paronychia 89.47％(17/19),nail psoriasis 100.00％(7/7),onychomycosis 70.00％(14/20),subungual hemorrhage 73.33％(11/15),melanonychia 14.29％(1/7),periungual warts 55.56％(5/9),and nail melanoma 42.86％(3/7).The micro F1 score for evaluating the dual-model strategy on a test set of 1 000 cases was 0.844.Conclusion The dual-model strategy can effectively combine models with different functions to well accomplish the task of intelligent diagnosis of nail diseases under small data volume training conditions.

Objective To systematically evaluate the efficacy and safety of hydromorphone or morphine for cancer pain using intrathecal drug infusion system(IDDS).Methods Chinese and English literature databases,including CNKI,Wanfang,VIP,CBM,PubMed,Cochrane Library,and Ovid,were searched from inception to Aug.31,2023 to collect randomized controlled trials(RCTs)about intrathecal infusion of morphine or hydromorphone in treatment of cancer pain.Two reviewers independently screened literature and extracted data according to the inclusion and exclusion criteria,and evaluated the quality of RCTs using a Cochrane bias risk assessment tool.Then,meta-analysis was performed using RevMan 5.4.1 software.Results A total of 6 RCTs,involving 544 patients,were enrolled.Among them,there were 282 cases in the hydromorphone group and 262 cases in the morphine group.The meta-analysis results showed that there were no significant differences in pain score or number of breakthrough pain episodes between the 2 groups after treatment(all P＞0.05).Compared with the morphine group,the incidence rates of nausea and vomiting,constipation,and somnolence were significantly decreased in the hydromorphone group(P≤0.05),and the quality of life was significantly higher(P＜0.05).Conclusion The efficacy of hydromorphone administered by IDDS for cancer pain is comparable to morphine;hydromorphone has advantages in reducing adverse reactions and improving quality of life of patients.