COVID-19 had caused the epidemic in Wuhan of China in December 2019. The asymptomatic infection of COVID-19 was found with the further research. This paper summarizes the discovery of the asymptomatic infection cases, analyzes their outcomes and transmission risks, and put forward the targeted suggestions for the prevention and control of asymptomatic infection of COVID-19 according to the existing problems in epidemic response.

Objective: To evaluate the value of computed tomography (CT) multi-planner reconstruction (MPR)in the treatment of lung cancer with percutaneous argon-helium cryoablation.Method:A total of 66 patients with stage T2 or T3 non-small cell lung can-cer who had complete follow-up data were treated with percutaneous argon-helium cryoablation with conventional axial CT(conven-tional group)or MPR guidance(MPR group)between January 2013 and 2016.There were 31 patients in the conventional group and 35 in the MPR group.The total number of punctures,the total time of operation,and the incidence of complications,tumor residual rates,and local control rates were compared between the two groups.Results:When the number of needles was the same,the aver-age number of punctures and puncture errors in the two groups were significantly lower in the MPR group than in the conventional group(P<0.05).Comparing the average operation time,there was no statistical difference between the MPR group and the conven-tional scan group(P>0.05).The incidence of postoperative complications was significantly lower in the MPR group than in the conven-tional scan group.Among them,the incidence of puncture combined hemorrhage was 1.52% vs.13.64%,and pneumothorax second-ary to puncture was 3.03% vs.19.70%(P<0.05).During the follow-up period to 12 months after surgery,the therapeutic benefit indica-tors such as local residual rate and total effective rate in the MPR group were also significantly better than those in the conventional group,which were 1.52% vs.10.61 and 51.52% vs.36.36%(P<0.05),respectively.Conclusions:Using MPR technology to guide percuta-neous argon-helium cryoablation treatment for lung cancer confers a small puncture error,low incidence of complications,and signifi-cant treatment benefits.This method is worthy of clinical promotion.

Objective To explore the value of artificial intelligence federated learning system based on chest X-ray films for pathogen diagnosis of community-acquired pneumonia(CAP)in children.Methods Totally 900 cases of CAP children from 2 hospitals were retrospectively enrolled,including bacterial,viral and mycoplasma CAP(each n=300),and chest posteroanterior X-ray films were collected.Meanwhile,chest posteroanterior X-ray films of 5856 children from the publicly available dataset GWCMCx were collected,including 4273 CAP images and 1583 healthy chest images.All above 6756 images were divided into training set(n=5359)and validation set(n=1397)at the ratio of 8∶2.Then a pathogen diagnosis model of children CAP was established based on attention mechanism.Binary and ternary diagnostic algorithms were designed,and federated deployment training was performed.The efficacy of this system for pathogen diagnosis of children CAP was analyzed and compared with DenseNet model.Results Based on all data,the accuracy of the obtained artificial intelligence federated learning system model for diagnosing children CAP was 97.00%,with the area under the curve(AUC)of 0.990.Based on hospital data,the AUC of this system using single imaging data and clinical-imaging data for pathogen diagnosis of children CAP was 0.858 and 0.836,respectively,both better than that of DenseNet model(0.740,both P＜0.05).Conclusion The artificial intelligence federated learning system based on chest X-ray films could be used for pathogen diagnosis of children CAP.

Objective To observe the drainage pathways of interstitial fluid(ISF)and substance clearance pattern in rat brain with fluorescence tracing imaging and treacer-based MRI.Methods Thirty-three male SD rats were randomly divided into fluorescence tracing group(F group,n=18)and treacer-based MRI group(MRI group,n=15),then further divided into thalamic,hippocampal and caudate nucleus subgroups,respectively.Evans blue was injected to rats in F group,and cardiac perfusion was performed after injection,then brain tissue was harvested,and frozen sections were made to observe the drainage pathways of IFS in different subgroups.MRI was performed on rats in MRI group before and after injection of gadolinium-diethylenetriamine pentaacetic acid(Gd-DTPA)to observe signal intensity in ROI of brain regions in different subgroups,the signal unit ratio was calculated,and the changing trend was explored.Results ISF in thalamus,hippocampus and caudate nucleus had different dominant drainage pathways,and the time of tracer reached to adjacent brain regions and whole brain in F group were different.In MRI group,within 4 h after injection of Gd-DTPA,there were differences in direction and clearance rate among tracer in thalamus,hippocampus and caudate nucleus,mainly manifesting as the tracer in thalamus and hippocampus drained to the ipsilateral cortex and lateral ventricle,while the tracer in the caudate nucleus diffused to the cortex and midbrain,and there were differences of the peak time of tracer signal among adjacent drainage brain regions.Conclusion Fluorescence and MR dual-mode imaging showed that there were differences in the dominant drainage pathways of IFS and clearance rates of small molecule substances among hypothalamus,hippocampus and caudate nucleus of rats.

Objective:To unveil the pathological changes associated with demyelination in schizophre-nia(SZ)and its consequential impact on interstitial fluid(ISF)drainage,and to investigate the thera-peutic efficacy of ursolic acid(UA)in treating demyelination and the ensuing abnormalities in ISF drainage in SZ.Methods:Female C57BL/6J mice,aged 6-8 weeks and weighing(20±2)g,were randomly divided into three groups:control,SZ model,and UA treatment.The control group received intraperitoneal injection(ip)of physiological saline and intragastric administration(ig)of 1％carboxy-methylcellulose sodium(CMC-Na).The SZ model group was subjected to ip injection of 2 mg/kg dizo-cilpine maleate(MK-801)and ig administration of 1％CMC-Na.The UA treatment group underwent ig administration of 25 mg/kg UA and ip injection of 2 mg/kg MK-801.The treatment group received UA pretreatment via ig administration for one week,followed by a two-week drug intervention for all the three groups.Behavioral assessments,including the open field test and prepulse inhibition experiment,were conducted post-modeling.Subsequently,changes in the ISF partition drainage were investigated through fluorescent tracer injection into specific brain regions.Immunofluorescence analysis was employed to examine alterations in aquaporin 4(AQP4)polarity distribution in the brain and changes in protein expres-sion.Myelin reflex imaging using Laser Scanning Confocal Microscopy(LSCM)was utilized to study modifications in myelin within the mouse brain.Quantitative data underwent one-way ANOVA,followed by TukeyHSD for post hoc pairwise comparisons between the groups.Results:The open field test re-vealed a significantly longer total distance[(7 949.39±1 140.55)cm vs.(2 831.01±1 212.72)cm,P＜0.001]and increased central area duration[(88.43±22.06)s vs.(56.85±18.58)s,P=0.011]for the SZ model group compared with the controls.The UA treatment group exhibited signifi-cantly reduced total distance[(2 415.80±646.95)cm vs.(7 949.39±1 140.55)cm,P＜0.001]and increased central area duration[(54.78±11.66)s vs.(88.43±22.06)s,P=0.007]compared with the model group.Prepulse inhibition test results demonstrated a markedly lower inhibition rate of the star-tle reflex in the model group relative to the controls(P＜0.001 for both),with the treatment group dis-playing significant improvement(P＜0.001 for both).Myelin sheath analysis indicated significant demy-elination in the model group,while UA treatment reversed this effect.Fluorescence tracing exhibited a significantly larger tracer diffusion area towards the rostral cortex and reflux area towards the caudal thala-mus in the model group relative to the controls[(13.93±3.35)mm2 vs.(2.79±0.94)mm2,P＜0.001 for diffusion area;(2.48±0.38)mm2 vs.(0.05±0.12)mm2,P＜0.001 for reflux area],with sig-nificant impairment of drainage in brain regions.The treatment group demonstrated significantly reduced tracer diffusion and reflux areas[(7.93±2.48)mm2 vs.(13.93±3.35)mm2,P＜0.001 for diffusion area;(0.50±0.30)mm2 vs.(2.48±0.38)mm2,P＜0.001 for reflux area].Immunofluorescence staining revealed disrupted AQP4 polarity distribution and reduced AQP4 protein expression in the model group compared with the controls[(3 663.88±733.77)μm2 vs.(13 354.92±4 054.05)μm2,P＜0.001].The treatment group exhibited restored AQP4 polarity distribution and elevated AQP4 protein expression[(11 104.68±3 200.04)μm2 vs.(3 663.88±733.77)μm2,P＜0.001].Conclusion:UA intervention ameliorates behavioral performance in SZ mice,Thus alleviating hyperactivity and anxiety symptoms and restoring sensorimotor gating function.The underlying mechanism may involve the improve-ment of demyelination and ISF drainage dysregulation in SZ mice.