Objective To investigate the Carabelli's traits on permanent maxillary molars in Han Chinese college students.Methods Intraoral photos and plaster models from 803 Han Chinese college students were observed and the Carabelli's traits on permanent maxillary molars were categorized by the Arizona State University Dental Anthropology System.Chi-square tests were performed for the comparison of the differences between male and female,permanent maxillary first and second molars.Kendall's tau-b correlation analy-ses were performed for the correlation between bilateral antimeric molars.Results The frequencies of Carabelli's traits on permanent maxillary first and second molars were 37.61％and 3.99％respectively,46.73％and 6.30％in males,27.95％and 1.54％in females,which were statistically significant between permanent maxillary first and second molars(P＜0.01),male and female(P＜0.01).In the positive expression,the low-grade expression(ASUDAS 1-4)was predominant and accounted for 67.37％and 59.52％on the perma-nent maxillary first and second molars.The correlation between bilateral antimeric teeth were statistically significant on permanent max-illary first molars(tau-b=0.756,P＜0.01)and second molars(tau-b=0.477,P＜0.01).Conclusion The Carabelli's traits on perma-nent maxillary molars in Han Chinese college students mostly occur on permanent maxillary first molars with low-grade expression,and understanding this has great anthropological and clinical significance.

In the various diseases of oral and maxillofacial system,the incidence of tissue defects is high and harmful,the reconstruction of the morphology and function is difficult,which seriously affects the physiological and mental health of the patients.Dental and maxillofacial regeneration based on stem cells and tissue engineering technology is a potential way for the treatment of dental and maxillofacial defects,and is also the focus of current international competition.Based on the possible mechanism of stem cells regulating organ development,this paper reviews the current status of dental and maxillofacial regeneration and translation,and proposes future direction in this field in order to pro-mote the sustainable development of dental and maxillofacial regeneration and translation.

Objective To explore the mechanism of acute liver injury induced by Cortex dictamni through network pharmacology and in vivo experiment in animal.Methods The chemical constituents and targets of Cortex dictamni were retrieved from TCMSP,TCMIP and SwissTargetPrediction databases,and the related targets of liver injury diseases were identified through GeneCards and CTD databases.The protein interaction network of the intersection targets was analyzed by STRING database and the core targets were selected.The GO function and KEGG pathway enrichment analysis were completed by DAVID database,and the multi-level association network diagram of"drug-component-target"was constructed by Cytoscape software.In the animal study,Cortex dictamni was administered to mice at a dosage of 92.7 g/(kg·d)via intragastric administration,and the biological samples were collected after 7 days.The pathological changes of liver were observed by hematoxylin-eosin(HE),Masson and Oil Red O staining.The expression levels of alanine aminotransferase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP),and lactate dehydrogenase(LDH)in serum,as well as malondialdehyde(MDA),superoxide dismutase(SOD),tumor necrosis factor-α(TNF-α),and interleukin(IL)-1β in liver tissues,were quantified using enzyme-linked immunosorbent assay(ELISA).The expressions of protein kinase B1(AKT1),IL-6,TNF-α,tumor protein p53(TP53),cystatin 3(CASP3),and IL-1β mRNA in liver tissues were determined using real-time quantitative reverse transcription PCR(qRT-PCR).Molecular docking was employed to verify the binding affinity of potentially toxic components to their respective targets.Results A total of 14 chemical constituents,244 predicted targets and 202 intersection targets with liver injury were obtained.The GO biological process analysis mainly involved positive regulation of gene expression,negative regulation of apoptosis process.KEGG pathway enrichment analysis mainly included cancer pathway and PI3K-Akt,TNF,IL-17 signaling pathways.The pathological sections revealed severe hemorrhage,a considerable amount of hepatocyte necrosis,nuclear fragmentation or dissolution in the liver tissues of mouse with HE staining after the administration of Cortex dictamni.Masson staining showed evident fibrosis in the liver tissues,while Oil Red O staining indicated a substantial production of lipid droplets.Compared with the control group,the ELISA results demonstrated a significant increase in serum AST,ALT,ALP,LDH levels,as well as hepatic MDA,TNF-α,and IL-1β levels(P<0.05),and a decrease in hepatic SOD levels(P<0.05)in the treated group.The qRT-PCR results indicated a significant elevation in the expression levels of relevant mRNAs in the liver tissues of the treated mice(P<0.05).Molecular docking showed that the potentially toxic components of obacunone,dictamnine and fraxinellon had good binding affinity to AKT1,IL-6,TNF-α,TP53,CASP3 and IL-1β.Conclusion Obacunone,dictamnine,fraxinellon,and limonin might be the potential toxic components of acute liver injury induced by Cortex dictamni in mice.Cortex dictamni could act on the liver by changing the expressions of AKT1,IL-6,TNF-α,TP53,CASP3,IL-1β and other proteins,affecting energy metabolism,cell differentiation,inflammation,oxidative stress and immunity,leading to liver injury.

Dictamni cortex is the root bark of Rutaceae plants.It is the main medicinal part and the key drug of 'Zhuhuang Fengbi'.It has the effects of clearing heat and detoxifying,dispelling wind and drying dampness,and relieving itching.Dictamni cortex mainly contains 228 chemical components such as alkaloids,sesquiterpenes,limonoids,fatty acids,volatile oils,flavonoids,steroids,etw.Its pharmacological activities in vivo and in vitro include antibacterial activity,anti-inflammatory activity,hepatoprotective activity,cardiovascular protection activity,insecticidal activity,anticancer activity,anti-allergic activity,and improvement of gastrointestinal activity.It has been reported that Dictamni cortex also has potential hepatotoxicity,among which dictamnine,fraxinellone and limonin compounds are potential hepatotoxic components.In this paper,the chemical constituents,pharmacological effects and toxicity of Dictamni cortex are reviewed by consulting domestic and foreign literature,to provide theoretical support for the clinical rational application and related product development of Dictamni cortex.

Bupleuri radix is the dried root of Bupleuri radix or narrow-leaved Bupleuri radix of the umbelliferae family,and it is the most commonly used traditional Chinese medicine,which was first published in Shennong's Classic of Materia Medica.It has a variety of pharmacological effects such as anti-inflammatory,antioxidant,hepatoprotective,antitumor,antidepressant,et al.In the modern study,the extract of Bupleuri radix mainly includes a variety of chemical components such as Bupleuri radix saponin,flavonoids and volatile oil.By reviewing the relevant literature at home and abroad,this paper summarizes the research progress on the chemical composition and pharmacological effects of Bupleuri radix,and points out the future research direction to provide a certain reference basis for the subsequent research.

Objective : To observe the clearance of smear layer on the root canal wall in different action time by scanning electron microscope (SEM), and to determine the optimal amount of time using sonically activated irrigation to wash root canal in clinic. Methods: Fifty-six ex vivo human anterior teeth with single straight root canal were selected. After routine mechanical preparation, they were divided into two experimental groups according to different irrigating agents: saline group and EDTA group. Each group was assisted by VDW sonic activation EDDY. The saline group was divided into three subgroups according to the irrigating time: 5 s, 30 s and 50 s; EDTA group was divided into six subgroups according to the irrigating time: 5 s, 10 s, 20 s, 30 s, 40 s and 50 s. The control group did not undergo root canal irrigation. After irrigation, the root was cut longitudinally. The smear layer of crown, middle and apical of root canal wall was observed by SEM. Results: After irrigating for 30 seconds, there was a significant difference between the normal saline group and the control group and the 5 second group (P<0.05), and there was no difference in the middle and apical part (P>0.05). After 50 seconds, there was a significant difference in the score of the smear layer between the apical area and the other groups (P<0.05). After irrigating for 5 seconds or 10 seconds in EDTA group, there was a significant difference between the scores of the crown and middle area of the root canal and the control group (P<0.05), and there was no significant difference in the apical area (P>0.05). There was a significant difference between the 20-40 second group and the first two groups (P<0.05). There was a significant difference between the 50 second group and the other groups (P<0.05). Comparing the cleaning effect on the smear layer after 50 seconds of irrigating between the two experimental groups, the whole root canal showed significant statistical difference (P<0.05). Conclusion The EDTA-assisted sonic activated device used for 50 seconds has the best cleaning effect.

Objective:To investigate the risk factors for acute cholangitis after endoscopic retrograde cholangiopancreatography (ERCP) and to construct its nomogram.Methods:Clinical data of patients who underwent ERCP for common bile duct stones in the First Hospital of Lanzhou University from January 2014 to December 2019 were retrospectively analyzed. A total of 95 patients with acute cholangitis after the operation (the acute cholangitis group) were included and 285 patients without acute cholangitis after the operation (the non-acute cholangitis group) were selected by random sampling at 1∶3 via the software. Logistic regression analysis was used to evaluate the risk factors for acute cholangitis after ERCP. A nomogram model was established to predict the incidence of acute cholangitis after ERCP based on the results of multivariate analysis.Results:Univariate analysis showed that there were significant differences in age, combination with diabetes, levels of alanine aminotransferase, alkaline phosphatase and glucose, roughness in gallbladder wall, bile duct diameter, stenosis in lower bile duct, proportion of patients who underwent endoscopic retrograde biliary drainage and endoscopic nasobiliary drainage between the two groups ( P<0.05). Logistic multivariate regression analysis showed that advanced age ( OR=1.108, 95% CI:1.079-1.138, P<0.001), combination with diabetes ( OR=4.524, 95% CI:1.299-15.758, P=0.018), roughness in gallbladder wall ( OR=2.495, 95% CI:1.106-5.630, P=0.028), increased bile duct diameter ( OR=1.303, 95% CI:1.181-1.437, P<0.001), and stenosis in lower bile duct ( OR=4.192, 95% CI:2.508-7.005, P<0.001) were independent risk factors for acute cholangitis after ERCP. Based on the results of multivariate analysis, the nomogram of acute cholangitis after ERCP was established. The area under the receiver operator characteristic curve was 0.887. Conclusion:Advanced age, combination with diabetes, rough gallbladder wall, increased diameter of bile duct and stenosis in lower bile duct are independent risk factors for acute cholangitis after ERCP. Clinicians can make clinical intervention based on the nomogram of risk factors above to improve the prognosis of patients.

Objective To investigate the relationship between serum secreted phospholipase A2 (sPLA2) and the severity of the disease in cobra bite patients. Methods Fifty-two cobra bite patients admitted to our hospital from January 2015 to December 2015 were selected according to the inclusion and exclusion criteria. According to the degree of disease, patients were divided into the light and heavy risk groups. According to the degree of swelling of the affected limbs, patients were divided into the mild swelling group and moderate-severe swelling group. According to the time difference between visits, patients were divided into: visit time <8 h group and visit time ≥ 8 h group. Twenty healthy adult volunteers served as the control group. The levels of serum sPLA2, C reactive protein (CRP), D-dimer (DD), lactic acid (LAC) and peripheral blood leukocyte count (WBC) were measured and compared in different groups. Quantitative data were analyzed using t test and rank sum test. Results The levels of serum sPLA2 in the light and heavy risk group were statistically different from those in the control group (P<0.05), and were statistically significant between the light and heavy risk groups (P<0.01) and between the mild swelling group and moderate-severe swelling group (P<0.05). The serum sPLA2 levels in group A and group B were also significantly different from those in the control group (P<0.05). The level of sPLA2 was positively correlated with the level of LAC, DD and WBC, and the correlation coefficients were 0.3142, 0.2752 and 0.6534, respectively. Conclusions The higher the level of serum sPLA2, the more serious the patient's poisoning symptoms. It is of certain clinical value to evaluate the condition of cobra.

Objective To investigate the effect of calcitonin gene-related peptide ( CGRP ) in inducing os-teogenic differentiation of rat precartilaginous stem cells in vitro and the underlying mechanisms. Methods Rat pre-cartilaginous stem cells ( PSCs) were cultured in complete osteogenesis medium containing DMEM/F-12 medium and different concentrations (0, 10-8,10-9,10-10mol/L) of CGRP, the morphology changes of PSCs were observed. The proliferation of PSCs was examined at different time points by CCK-8. All the PSCs were then randomly assigned to an experimental group and a control group. The PSCs in the experimental group were cultured in complete osteogenesis medium with 10-10 mol/L CGRP , while the control group cultured merely in complete osteogenesis medium was re-ceived no special intervention. Both groups were stained by Alizarin Red and the expression of alkaline phosphatase (ALP) was detected. The osteogenic genes (RUNX2,OPN and BGP) were measured by use of RT-PCR. The activa-tion of Wnt/β-catenin signaling pathway was tested by using Western blotting to evaluate the effect of CGRP . Results Compared to the control group ( the concentration of CGRP was 0 mol/L) , the concentration of ALP was significantly higher in the experimental group, calcium deposition was significantly more obvious, and the expression of the osteogenic genes such as RUNX2,OPN and BGP as well as theβ-catenin protein expression were up-regulated significantly. However, CGRP had no effect on cell proliferation. Conclusion CGRP activated Wnt/β-catenin sig-nal pathway and induced osteogenic differentiation of precartilaginous stem cells.

Objective:To explore the expression of C-terminal binding protein 2 (CtBP2) in human esophageal carcinoma and its relationship with clinicopathological parameters and survival. Methods:The expression levels of CtBP2 in eight cases of fresh frozen specimens of esophageal squamous cell carcinoma (ESCC) and the adjacent esophageal tissues were detected by Western blot. Immuno-histochemistry was used to detect CtBP2 expression in 90 samples of ESCC tissues and adjacent non-tumor tissues. Based on patient in-formation and follow-up data, the correlation of CtBP2 expression with patients' clinicopathological characteristics and overall survival was further evaluated using Fisher's exact test and Kaplan-Meier method, respectively. Results: Immunohistochemistry and Western blot analysis showed that CtBP2 expression in tumor tissues was higher than that in adjacent non-tumor tissues. CtBP2 expression was significantly correlated with histologic grade (P=0.002) and depth (P=0.032). Kaplan-Meier analysis demonstrated that high CtBP2 ex-pression was correlated with a short survival time. Conclusion:CtBP2 expression was upregulated in ESCC tissues, indicating that it may play a role in the oncogenesis and development of ESCC.