People wearing positive pressure biological protective suits might face some potential safety risks when work -ing in a high-risk biological contamination environment .These risks could be effectively prevented by simulation experi-ments.This paper elaborates on the progress in risk studys on positive pressure biological protective suits in terms of dynam -ic detection methods and risk assessment , and points out the problems to be solved and the direction of future development .

Objective To evaluate the capability of virtual non-contrast (VNC)of the second-generation dual-source CT (DSCT), and to display the adipose tissue of gastric serosa.Methods 48 patients with gastric cancer undergoing preoperative DSCT and sur-gery were enrolled.The true non-contrast (TNC)values and VNC values of perigastric adipose tissue were measured and compared with conventional non-contrast scanning and VNC of arterial phase and venous phase.The VNC values of perigastric adipose tissue were compared between serosal involvement group and non-serosal involvement group.Results There was statistical difference be-tween TNC values and VNC values of perigastric adipose tissue (P <0.05),the absolute differences were under 13 HU.The differ-ence of VNC values between serosal involvement group and non-serosal involvement group was significant (P <0.05).Conclusion VNC of the second-generation DSCT can clearly display the adipose tissue of gastric serosa.It has certain capability in judging sero-sal involvement.VNC has the proficiency to replace conventional non-contrast scanning.

Objective To investigate the clinical utility of dual-energy virtual non-contrast CT(VNCT)of dual source CT in the di-agnosis and differential diagnosis of solitary pulmonary nodule(SPN).Methods Thirty-six patients with suspected SPN underwent chest plain single energy CT and dual-phase contrast enhanced CT (DECT)(25 and 90 s).The images of dual energy were sent to a commercial workstation for VNC image generation.CT values of SPN on VNC and true non-contrast(TNC),as well as signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were compared.The accuracy of calcification detection was compared according to the diameter and density of the calcification.The TNC images were used as the reference.Results CT values,SNR and CNR of VNC had no statistical difference among TNC and VNC at 25 s and 90 s(P >0.05).DECT VNC(5mm slice)could accurate detected calci-fication(diameter>2 mm,CT value>1 50 HU)in SPN.The 2 mm slice performed significantly better than 5 mm slice VNC images. Conclusion The VNC could provide consistent diagnostic information with TNC.The thin slice DECT VNC images can be used in clinical practice to replace TNC without losing small calcification in SPN,which has potential to reduce the patient radiation dose.

Objective To investigate the feasibility of a rat carotid atherosclerosis model induced by artery clamping with high-cholesterol diet and vitamin D3.Methods Twenty Wista rats were randomly divided into either a general diet group (n =5) or a high cholesterol diet group (n =15).After clamping the right common carotid arteries of the rats in the high cholesterol diet group,they were fed with high fat diet,and vitamin D3 (600 000 IU/kg) was injected intraperitoneally.The lipid levels of the general diet group and the high cholesterol diet group were detected at 6 and 12 weeks respectively.The bilateral cormmon carotid arteries were selected for preparing paraffin sections and were stained with HE staining.The pathological changes in blood vessels were observed.Results The levels of serum total cholesterol at 12 weeks (2.803 ± 1.307 mmol/L vs.1.513 ±0.281 mmol/L; P=0.017) and low-density lipoprotein cholesterol (0.660± 0.260 mmol/L vs.0.311 ±0.078 mmol/L; P =0.003) in the high-cholesterol diet group were significantly higher than those at 6 weeks.The histopathological examination showed that the common carotid artery intimas on the clamping sides were incomplete,the foam cell deposition was observed under intima,the atherosclerotic plaques or fibrous plaques were observed on the surface of cavity,inside the plaques contained necrotic tissue,and thrombosis was observed in the cavity.The common carotid artery intima-media thickness in the general diet group (n =5) at 12 weeks was 8.3 ± 1.1 μm.The sham-operated sides (n =20) and clamping sides (n =20) were 8.8 ± 0.7 μm and 97.4 ±25.7 μm,respectively.There were significant differences among the three groups (F =116.313,P=0.000).The clamping sides in the high-cholesterol diet group were significantly higher than the shamoperated sides in the high-cholesterol diet group (P=0.000) and the general diet group (P =0.000).Conclusions Common carotid artery clamping with high-cholesterol diet and vitamin D3 is a simple and feasible method for inducing a rat carotid atherosclerosis model.

Objective To investigate the intra- and interobserver repeatability of coronary artery disease (CAD) diagnosis based on invasive coronary angiography (ICA) and CT coronary angiography (CTCA).Methods Two readers with comparable experience ( over 10 years) independently evaluated ICA results of 42 consecutive patients with a blind method. After 30 days,one of them reviewed the same patients again.Another two comparable-experience (over 10 years) readers evaluated the results of CTCA (prospectively ECG-triggering) from the same 42 patients in the same way.The inter-reader and intra-reader repeatability of ICA and CTCA were analyzed by performing Kappa test and calculating the percentage of the segments with agreement on stenotic degree.Using ICA as reference,the accuracy of CTCA in diagnosing CAD was studied by comparing the area under ROC. Results The Kappa between readers for ICA and CTCA were 0.91 and 0.81.Intra-reader Kappa were 0.92 and 0.83 respectively (x2 =509.4 and 432.5,all P ＜0.01 ).The percentage of the segments with agreement between readers on the degree of stenosis were 80.8％ (494/611) in ICA and 75.2％ (469/624) in CTCA ( x2 =2.75,P =0.10),and within the same reader,86.9％ (531/611)in ICA and 81.9％ (511/624) in CTCA(x2 =3.76,P =0.053).With≥ 50％narrowing as a CAD diagnosis criterion,the agreement rates for two readers were 96.6％ (590/611 ) in ICA and 94.4％ (589/624) in CTCA( x2 =3.36,P =0.07),and for the same reader,97.4％ (595/611) in ICA,95.4％ (595/624) in CTCA ( x2 =3.62,P =0.06).Using ICA as reference,two readers of CTCA results achieved a sensitivity and specificity of 84.9％ (530/624)and 98.1％ (612/624).The area under ROC was 0.94 (95％ CI 0.91-0.97).Conclusions Both ICA and CTCA demonstrate good repeatability in diagnosing CAD.The repeatability of ICA is superior to that of CTCA.A certain discrepancy exists in two readings from the same reader or two readers.

BACKGROUND:Existing studies have confirmed that exosomes can effectively promote pulp regeneration.However,the biological functions and properties of exosomes from preconditioned sources can be significantly changed,which have different effects on cell proliferation,migration and odontogenic differentiation. OBJECTIVE:To discuss the application status of exosomes and their preconditioning methods in the field of pulp regeneration,and summarize the preconditioning methods that affect the function of exosomes,and explore the effect of exosomes and their preconditioning on pulp regeneration. METHODS:The relevant articles were searched in WanFang,CNKI,PubMed,and Web of Science databases from 2006 to 2022.The Chinese and English search terms were"exosomes,pulp regeneration;preconditioning method".A total of 78 articles were included for analysis. RESULTS AND CONCLUSION:(1)Exosomes have the advantages of good biocompatibility,low immunogenicity and no cytotoxicity,and can induce the regeneration of pulp tissue by promoting stem cell tooth formation,neurogenesis and vascularization.(2)Exosomes derived from preconditioning can enhance the ability of tissue repair and regeneration and have a significant impact on the quality of regenerated dental pulp.(3)Currently,the preconditioning methods used in the field of dental pulp regeneration include inflammatory stimulation,hypoxia induction,conditioned medium and three-dimensional culture,and secreted exosomes can effectively improve the quality of regenerated dental pulp.Nevertheless,the specific effect and mechanism of different preconditioning methods on pulp regeneration need to be explored.

Sepsis-induced liver injury (SILI) is an important cause of septicemia deaths. BaWeiBaiDuSan (BWBDS) was extracted from a formula of Panax ginseng C. A. Meyer, Lilium brownie F. E. Brown ex Miellez var. viridulum Baker, Polygonatum sibiricum Delar. ex Redoute, Lonicera japonica Thunb., Hippophae rhamnoides Linn., Amygdalus Communis Vas, Platycodon grandiflorus (Jacq.) A. DC., and Cortex Phelloderdri. Herein, we investigated whether the BWBDS treatment could reverse SILI by the mechanism of modulating gut microbiota. BWBDS protected mice against SILI, which was associated with promoting macrophage anti-inflammatory activity and enhancing intestinal integrity. BWBDS selectively promoted the growth of Lactobacillus johnsonii (L. johnsonii) in cecal ligation and puncture treated mice. Fecal microbiota transplantation treatment indicated that gut bacteria correlated with sepsis and was required for BWBDS anti-sepsis effects. Notably, L. johnsonii significantly reduced SILI by promoting macrophage anti-inflammatory activity, increasing interleukin-10⁺ M2 macrophage production and enhancing intestinal integrity. Furthermore, heat inactivation L. johnsonii (HI-L. johnsonii) treatment promoted macrophage anti-inflammatory activity and alleviated SILI. Our findings revealed BWBDS and gut microbiota L. johnsonii as novel prebiotic and probiotic that may be used to treat SILI. The potential underlying mechanism was at least in part, via L. johnsonii-dependent immune regulation and interleukin-10⁺ M2 macrophage production.

[This corrects the article DOI: 10.1016/j.apsb.2022.10.016.].