ObjectiveTo investigate the potential mechanisms of Zhimu （Anemarrhena asphodeloides）-Huangbai （Phellodendron amurense） medicinal pair in alleviating postmenopausal osteoporosis （PMOP）. MethodsSixty unpregnant female SD rats were randomly divided into five groups， blank group， model group， low-dose Zhimu-Huangbai group， high-dose Zhimu-Huangbai group， and estradiol group， with 12 rats in each group. Except for the blank group， all other groups had their ovaries removed to create PMOP rat models， while the blank group only had the fat tissue around the ovaries removed. One week after the ovarian removal， the low-dose and high-dose Zhimu-Huangbai groups received concentrated solution of Zhimu and Huangbai with 1.8， 7.2 g/（kg·d） via gavage， the estradiol group received estradiol solution 0.09 mg/（kg·d） via gavage， and the blank group and the model group received 10 ml/（kg·d） of normal saline via gavage， once daily for 12 weeks. Before sampling， the body mass of the rats was recorded， and uterine tissue was taken to calculate the uterine index. The levels of interleukin-1β （IL-1β）， interleukin-6 （IL-6） and tumor necrosis factor-α （TNF-α） in serum were detected by ELISA； micro CT was used to examine the parameters of femoral microstructure， including bone volume/tissue volume （BV/TV）， trabecular number （Tb.N）， trabecular thickness （Tb.Th）， bone mineral density （BMD）， trabecular separation （Tb.Sp）， and cortical bone area （Ct.Ar）. HE staining was used to observe pathological changes in the femur； RT-qPCR was used to detect the mRNA expression of osteogenic-adipogenic differentiation-related factors in femoral tissue， including Runt-related transcription factor 2 （Runx2）， bone morphogenetic protein 2 （BMP-2）， peroxisome proliferator-activated receptor γ （PPARγ）， chemerin and chemokine-like receptor 1 （CMKLR1）. ResultsCompared with the blank group， the model group showed a significant increase in body mass， a significant decrease in the uterine index， BV/TV， Tb.N， Tb.Th and BMD， a significant increase in Tb.Sp， and serum IL-1β， IL-6， and TNF-α levels， a significant reduction of mRNA expression of Runx2 and BMP-2 in bone tissue， and a significant increased mRNA expression of PPARγ， chemerin， and CMKLR1 （P＜0.01）. HE staining revealed that the femoral tissue showed a reduction and sparsity of trabeculae， a significant enlargement of the medullary cavity， and a large number of fat cells. Compared to the model group， the low-dose， high-dose Zhimu-Huangbai groups， and estradiol group showed significant improvements in all the above-mentioned indicators （P＜0.05 or P＜0.01）. HE staining revealed a significant increase in trabeculae， more organized arrangement， and a marked reduction in fat cells. Compared to low-dose Zhimu-Huangbai group， the high-dose Zhimu-Huangbai group exhibited a significant increase in the uterine index and BMD， and a significant reduction in body mass and PPARγ and Chemerin mRNA expression （P＜0.05 or P＜0.01）. Compared to high-dose Zhimu-Huangbai group， the estradiol group showed a decrease in uterine index， BV/TV， Tb.N， Tb.Th， BMD， and BMP-2 mRNA expression， while the levels of IL-1β， TNF-α， and IL-6， as well as Tb.Sp and the mRNA expressions of PPARγ， chemerin， and CMKLR1 increased （P＜0.05 or P＜0.01）. ConclusionThe Zhimu-Huangbai medicinal pair can alleviate PMOP bone loss， and its mechanism of action is related to reducing the levels of inflammatory factors， correcting the disorder of osteogenic-adipogenic differentiation of bone marrow mesenchymal stem cells （BMSCs）， and promoting the differentiation of BMSCs into osteoblasts.

Objective To explore the impact of non-pharmaceutical interventions(NPIs)on the prevalence of respiratory pathogens in adults,and to understand the scientific value and long-term effect of NPIs.Methods A retrospective study was conducted to collect the clinical data and laboratory examination data of adult patients with respiratory tract infection in West China Hospital,Sichuan University from 2017 to 2023,and the patho-gen,population,season and other aspects were analyzed in different periods.The analysis period included 2017 to 2019(before the implementation of NPIs),2020 to 2022(during the implementation of NPIs),and January to December 2023(after the implementation of NPIs).Results A total of 33 068 adult patients with respira-tory tract infection were included.The overall prevalence of 8 adult respiratory pathogens from 2017 to 2019(26.95％)was higher than that from 2020 to 2022(8.70％),and the difference was statistically significant(P＜0.05).There were significant differences in the prevalence of pathogens among different genders,ages and seasons in the first,middle and last three periods of NPIs implementation(P＜0.05).Before the imple-mentation of NPIs,the seasonal peak of respiratory prevalence appeared from January to March each year.With the implementation of NPIs,the seasonal peak of respiratory prevalence appeared from January to March 2020(10.09％),October to December 2021(9.32％),July to September 2022(15.23％),respectively.After the implementation of NPIs,the seasonal peak of respiratory prevalence appeared from October to December 2023(21.20％).Among the 8 pathogens,the change of prevalence of influenza A virus H1N1(2009)was the most obvious,and the prevalence was 17.42％,0.00％and 6.99％before,during and after the implementation of NPIs,respectively.Conclusion Due to the influence of NPIs and other factors,the epidemic characteristics of respiratory pathogens have changed from 2017 to 2023.Attention to the emerging characteristics of patho-gen prevalence is important for the prevention,diagnosis and control of respiratory infectious diseases during public health emergencies.

The establishment of effective animal models is crucial for disease research.Dietary induction is a common method to establish animal models of non-alcoholic fatty liver disease(NAFLD).The common animal models of diet-induced NAFLD mainly include high fat and sugar,high fat and cholesterol,and choline-deficient diet-induced models.Because of the various nutrients ingested in different modeling method,pathological characteristics of the liver,such as fatty deformation,inflammation,and fibrosis,are different.Additionally,animal models vary in terms of disease progression,disease severity,and applicable studies.This study analyzed and compared the common animal models of NAFLD induced by various diets in terms of modeling method,modeling time,pathological characteristics,applicable research,and related advantages and disadvantages to provide a reference for NAFLD researchers to select animal models.

Objective:To investigate the effectiveness of a digital virtual simulation training system applied in the preclinical teaching of access and coronal cavity preparation.Methods:Twenty dental undergraduate students from Peking University School and Hospital of Stomatology were recruited and divided randomly and equally into two groups according to the random number method after being unified with theory training, including access and coronal cavity preparation skills assessment form and Simodont system operation manual. Tests for access and coronal cavity preparation skills by using standard simulation plastic teeth were performed and the scores were recorded as baseline for each student. Students in group of virtual simulation priority were trained using Simodont virtual simulation system, while those in group of phantom-simulator priority were trained using conventional phantom-simulator system. Access and coronal cavity preparation skills of standard simulation plastic teeth were assessed once again and recorded as the second scores for the two groups. Furthermore, the two groups of students exchanged training systems and were assessed and graded once more as the third scores. Finally, all students were asked to fill up a Teaching Questionnaire after the training. The data were then collected and analyzed.Results:For the group of virtual simulation priority, after the training by using Simodont virtual simulation system and conventional phantom-simulator system, the mean score of access and coronal cavity preparation (16.00±1.49) was significantly higher than the baseline score (13.30±1.41) ( P<0.05). For the group of phantom-simulator priority, after the training by using conventional phantom-simulator system and Simodont virtual simulation system, the mean score of access and coronal cavity preparation (15.60±1.26) was also significantly higher than the baseline score (13.00±1.89) ( P<0.05). Furthermore, in the group of virtual simulation priority, of which the students were trained by using Simodont virtual simulation system first and then conventional phantom-simulator system, the score of access and coronal cavity preparation was significantly higher than the score of training by using conventional phantom-simulator system only (14.30±1.77) ( P<0.05). In the group of phantom-simulator priority, of which the students were trained by using conventional phantom-simulator system first and then Simodont virtual simulation system, the score of access and coronal cavity preparation was significantly higher than the score of training by using Simodont virtual simulation system only (14.10±1.45) ( P<0.05). Moreover, in the group of virtual simulation priority, the score of training by using conventional phantom-simulator system after using Simodont virtual simulation system was significantly higher than that of training by using Simodont virtual simulation system only ( P<0.05). The results of the questionnaire showed that the students fully agreed that "the Simodont virtual simulation system has the characteristics of repeatability, multi-dimension and multiple practice, and provides me with more attention to details" [80% (16/20)], however "it needs to be improved and upgraded to be close to the conventiaonl phantom-simulator system" [90% (18/20)]. Conclusions:Compared with using the conventional phantom-simulator system only, the preclinical teaching effectiveness of access and coronal cavity preparation could be effectively improved by using Simodont virtual simulation system combined with the phantom-simulator training system and might influenced by the training sequence.

Electrospinning technology is currently the only technology capable of directly and continuously preparing polymer nanofibers. It can prepare a variety of nanofibers with different characteristics by using high voltage electrostatic field. These electrospun nanofibers have an inherently high porosity, high surface-to-volume ratio and good mechanical properties, allowing the engineering of scaffolds with a nanoscale topography and high porosity similar to that of the natural extracellular matrix (ECM) to facilitate cell attachment, migration, proliferation, differentiation and functional expression. Thus, electrospun nanofibers have been widely applied in tissue engineering for different purposes such as bone, cartilage, neural, vascular, and skin regeneration and are being developed for pulp regeneration. This review briefly describes the preparation process and biological characteristics of electrospun nanofibers; furthermore, the most recent and state-of-the-art work on electrospun nanofibrous scaffolds, primarily their composition and structure in pulp tissue engineering, is introduced.

Objective: To investigate the effects of Kaixin Powder on learning and memory, ATP/AMP ratio, GABA andiNOS levels in rats with multiple infarct dementia. Methods: The rat model of multi-infarct dementia was established bymicro-thromboembolism. Morris water maze and opening experiment were used to evaluate learning and memoryfunction. The pathological changes of hippocampal CA1 area were evaluated by HE staining. The contents of ATP andAMP in brain tissue were determined by HPLC. The content of γ-aminobutyric acid and iNOS in peripheral blood weredetected by ELISA kit. Results: Compared with the rats of model group, rats of Kaixin Powder group can significantlyshorten the escape latency, increase the number of crossing platforms, Results: Compared with the model group, increasethe standing times in the opening experiment, prolong the exercise time, shorten the resting time, improve the nerve celldamage in the hippocampal CA1 area, and significantly increase the ratio of ATP/AMP of brain tissue, decreased brainGABA content and serum iNOS content (P ＜ 0.05) . Conclusion: Kaixin Powder has the effect of improving learning andmemory function and abnormal motor behavior in rats with multiple infarct dementia. The mechanism is related toreducing GABA and i NOS content in brain tissue, increasing ATP/AMP ratio in brain tissue and improving energysupply in brain tissue.

Objective To explore the structure changes of white matter in the first-episode schizo-phrenic patients with never-medicated(FESZ)and the relationship between facial emotion perception and white matter(WM)integrity.Methods Sixty-three schizophrenic patients and thirty health control subjects underwent diffusion tensor imaging(DTI)scans.Voxel-based analysis was used to compared fractional ani-sotropy(FA)map between the two groups.Correlations were analyzed with pearson relative analysis between impaired facial emotion perception tested by facial emotion categorization(FEC)and severity of symptoms measured by the Positive and Negative Syndrome Scale(PANSS).Results (1)Compared with controls, FESZ patients showed overall decreased FA in WM of the body of left ventral frontal lobe((MNI(x,y,z):-18,26,-4;t=4.43)),right supramarginal gyrus((MNI(x,y,z):32,-50,26;t=4.27)),left middle oc-cipital gyral((MNI(x,y,z):-26,-60,0;t=4.89)),right middle occipital gyral((MNI(x,y,z):28,-70, 14;t=4.18)),left fusiform gyrus((MNI(x,y,z):-40,-50,0;t=3.92)),left cerebellum anterior lobe ((MNI(x,y,z):-32,-56,-28;t=4.57)),right parahippocampa gyrus1((MNI(x,y,z):32,-10,-14;t=4.16)),right parahippocampa gyrus2((MNI(x,y,z):16,-6,-14;t=4.56)),left anterior cingulate ((MNI(x,y,z):-2,4,-6;t=4.41)),left extra-nuclear((MNI(x,y,z):-2,-10,-6;t=4.44)),right thalamus((MNI(x,y,z):10,-10,2;t=4.20)),left thalamus((MNI(x,y,z):-22,-28,12;t=4.01)), and right caudate((MNI(x,y,z):14,12,8;t=4.87)).(2)Compared with controls,the patients with schizo-phrenia showed a higher shift point and a steeper slope than control subjects in FEC.Correlational analysis re-vealed that the negative correlations were found between the slope and negative factor(r=-0.298,P=0.036),between positive factor and the FA value in WM of the right middle occipital gyral(r=-0.322,P=0.023)and the left middle occipital gyral(r=-0.288,P=0.043),and between the FA value in the left cere-bellum anterior lobe and shift point(r=-0.393,P=0.005),but the positive correlation was found between disorganized/concrete factor and the FA value in the right parahippocampal gyrus(r=0.429,P=0.002).Con-clusions There are extensive microstructural abnormalities in WM of patients with FESZ.Disrupted WM in-tegrity in these regions may constitute a potential neural pathological basis for the facial emotion perception impairments in schizophrenia.

Objective:To investigate the effect of thermal conductivity on the apical sealing ability of different dental gutta-percha cones during the warm vertical condensation obturation.Methods:Four kinds of dental gutta-percha cones were used in this study:Bio-GP points (BP,B&L,Korea),large-tapered gutta-percha (DP,DENTSPLY,America),PROTAPER Universal gutta-percha points (DPP,DENTSPLY,America) and mtwo gutta-percha points (VP,VDW,Germany).Volume differences method was used to determine the main components and the thermal conductivity determinator was used to measure the thermal conductivity of these dental gutta-percha cones.Furthermore,20 cones randomly selected from each kind of dental gutta-percha cones.And 10 cones of each dental gutta-percha cones,which were cut out the part of 4 mm in length from the apical end,were heated (200 ℃) from the upper end without compression,and the temperature of the gutta perchacones surface was monitored in time by the infrared thermal imager during the whole heating process.In addition,the rest of the 10 cones of each dental gutta-percha cones were used to obturate the root canal in the transparent root canal resin model using warm vertical condensation technique.The cross-sectional surface was observed by stereomicroscope (× 40) at 1 mm and 3 mm from the working length and the gutta-percha obturation area proportion was measured and analyzed.The data were analyzed by one-way ANOVA.Results:The proportion of inorganic fillers (80.90％ ± 1.14 ％) (P ＜ 0.05) and the thermal conductivity (2.247 ± 0.002)of DP was siguificantly higher than BP (79.28％ ± 3.88％,1.179 ± 0.003),DPP (68.46％ 5.09％,0.604 ±0.001),VP (78.86％ ± 1.87％,1.150 ±0.001) (P ＜0.05).During the thermal obturation without compression at the setting temperature (200 ℃),DP could achieve 65 ℃ beyond 1 mm from the heating point,and BP,DPP and VP only reached 65 ℃ within 1 mm.After warm vertical condensation obturation,all the groups showed increased gutta-percha obturation area proportion.At the position of WL-3,DP (96.89％ ±0.03％) showed significantly higher proportion of gutta-percha obturation area than BP (95.47％ ±0.06％),DPP (95.21％ ±0.03％) and VP (95.15％ ±0.03％) (P ＜ 0.05).Conclusion:DP contains more inorganic fillers,possesses higher thermal conductivity,and leads a better apical sealing ability than BP,DPP and VP at the position of WL-3 during warm vertical condensation obturation.

Objective: To investigate surface properties of novel flowable composites after polishing and simulated brushing wear, compared to their pasty counterpart. Methods: Composites employed in this study were: three flowable composites (A1: Clearfil Majesty ES Flow; B1: Beautifil Flow Plus F00; C1: Filtek Bulk Fill) and three paste composites (A2: Clearfil Majesty; B2: Beautifil; C2: Filtek Z350. Eleven disk-shaped specimens were made for each material. The specimens were cured, then subjected to sandpaper finishing for 20 s, one-step polishing for 30 s, finally subjected to simulated brushing for 10 000 cycles. Surface roughness and glossiness were measured before finishing, after finishing, after polishing, after 5 000 brushing cycles and after 10 000 brushing cycles, respectively. Data obtained were analyzed using two-way ANOVA method. Scanning electron microscope was employed to examine the microscopic appearance of each material. Results: Surface roughness (0.11~0.22 μm) and glossiness (74.25~86.48 GU) of each material were similar after one-step polishing. After brushing simulation, roughness increased significantly and glossiness decreased significantly for each material (P<0.05). Group A1 presented the best gloss ([50.68±1.58] GU) after final wear (P<0.05). Flowable composites of group A1 and B1 tested in the present setup showed better surface properties compared to their pasty counterpart (group A2 and B2). Conclusions Within the limit of this study, flowable composites tested in the present research can obtain similar surface polish or even better than the paste composite counterpart.

Objective:To investigate the antibacterial effect of different self-etching adhesive systems against Streptococcus mutans (S.mutans).Methods:Six reagents ClearfilTM SE Bond primer (SP), ClearfilTM SE Bond adhesive (SA),ClearfilTM Protect Bond primer (PP),which contained antibacterial monomer methacryloyloxydodecylpyridinium bromide (MDPB),ClearfilTM Protect Bond adhesive (PA), positive control chlorhexidine acetate [CHX,1% (mass fraction )],and negative control phosphate buffer solution (PBS)were selected.They were mixed with S.mutans for 30 s respectively,then colony-forming units (CFU)were counted after incubated for 48 h on brain heart infusion (BHI)agar medium. The 6 reagents were applied to the sterile paper discs,and distributed onto the BHI agar medium with S. mutans and incubated for 24 h,then the inhibition zones were observed.CHX,PBS,PP,and SP were added on the dentin with artificial caries induced by S.mutans and kept for 30 s,then confocal laser scanning microscope (CLSM)was used to observe the live and dead bacteria after staining.The ratio of live to dead bacteria was calculated.PP+PA and SP+SA were applied on the dentin according to the manual and light cured.S.mutans were incubated on the samples for 2 h,ultrasonically treated and in-cubated on BHI agar medium for 48 h,then CFU was counted.The data were analyzed by non-parametric analysis and one-way ANOVA.Results:Compared with PBS,the PP,SP,PA,SA and CHX showed the antibacterial effect on free S.mutans (P<0.05 );SP and PP showed stronger antibacterial effect than PA,SA and CHX (P<0.05).CHX,SP and PP presented inhibition zones,while PBS,SA and PA did not.Compared with PBS,the CHX,SP and PP could lower the ratio of the live to dead bacteria significantly (P<0.05).Cured self-etching adhesive systems did not show any antibacterial effect on the free S.mutans.Conclusion:The primer of self-etching adhesives ClearfilTM SE Bond and ClearfilTM Pro-tect Bond showed significant antibacterial effect on free and attached S.mutans.The adhesive only showed antibacterial effect on free S.mutans before light-cured polymerization.After being cured,the self-etching adhesive systems did not show antibacterial effect anymore.