The wide application of digital scanning technology in the field of dentistry has made medicine more modern and conven-ient.It has become popular to obtain digital face models through facial scanning systems.In order to reproduce the perfect maxillofacial shape and proportion,accurate facial scanning equipment is indispensable.For all kinds of facial scanners on the market,their working principles and scanning characteristics are not the same.This article will summarize the development of digital facial scanning technolo-gy,introduce different technical principles and discuss the clinical application,and look into the application prospect of this technology in the medical field.The limitations of this technology are proposed,in order that the digital facial scanning technology can be better applied in clinical practice.

Objective To investigate the effects of exposure to various concentrations of cigar smoke on gut microbiota in mice.Methods A total of 40 C57BL/6 mice were randomly divided into the control group,the low-dose cigar exposure group,the medium-dose group and the high-dose group,with 10 mice in each group.After 4 weeks of feeding,fecal samples were collected for gene sequencing of 16S ribosomal RNA and analysis of differences in gut microbiota.Results Compared to the control group,gut microbiota richness was signifi-cantly reduced in the cigar-exposed groups(P<0.05).Compared with thecontrol group,the Shannon index of mice in the high-dose group was significantly increased(P<0.05).In multi-group comparisons,ten bacterial genera with high abundance-such as Akkermansia,Allobaculum,and Alloprevotella-were identified.Pairwise comparison results indicated that compared to the control group,abundances of Akkermansia,Candidatus_Sac-charimonas,and Lactobacillus decreased while those of Allobaculum,Alloprevotella,Muribaculaceae,and Pre-votellaceae_UCG001 increased(P<0.05).Alistipes and Faecalibaculum showed significant increases in low-dose and medium-dose groups respectively,Blautia and Lachnospiraceae_NK4A136 group exhibited notable in-creases in the high-dose group(P<0.05).Linear discriminant analysis effect size revealed that six phyla and forty-four species displayed significant differences across all groups at both phylum and species levels,distinct dose-specific were observed among different cigar exposure groups.Conclusion Cigar smoke exposure and different exposure concentrations can both cause changes in the gut microbiota.The effects of different con-centrations of cigars on the gut microbiota of mice are specific.

The wide application of digital scanning technology in the field of dentistry has made medicine more modern and conven-ient.It has become popular to obtain digital face models through facial scanning systems.In order to reproduce the perfect maxillofacial shape and proportion,accurate facial scanning equipment is indispensable.For all kinds of facial scanners on the market,their working principles and scanning characteristics are not the same.This article will summarize the development of digital facial scanning technolo-gy,introduce different technical principles and discuss the clinical application,and look into the application prospect of this technology in the medical field.The limitations of this technology are proposed,in order that the digital facial scanning technology can be better applied in clinical practice.

Objective:To analyze the genetic and molecular characteristics of H9N2 subtype avian influenza viruses from external environment and humans in Anhui Province from 2013 to 2022.Methods:Environmental samples and human samples were collected from Anhui influenza surveillance network laboratory. Sixty-three strains of virus were isolated in chicken embryos. RT-PCR was used to amplify the virus and whole genome sequencing was performed. To construct gene evolutionary tree and analyze its genetic characteristics and potential glycosylation sites.Results:The hemagglutinin (HA) gene belongs to the 9.2.4.5 clade, and the protein cleavage sites are mostly " PSRSSR\GL". The neuraminidase (NA) gene, basic protein-1(PB1) gene, acidic protein (PA) gene, non-structural protein (NS) gene and nucleoprotein (NP) gene belong to the F/98 clade, the matrix protein (MP) gene belongs to the G1/97 clade, and the basic protein-2 (PB2) gene belongs to the ST/7488 clade. Mutations of T155N, R164Q, H183N, T189D/V, A190V/T and Q226L occurred in HA protein, deletion of NA protein occurred at 62-64 sites, and mutations of T271A, I292V/M and E627V/L occurred in PB2 protein. At the same time, mutations of K356R and S409N occurred in the PA protein.Conclusions:The H9N2 subtype avian influenza viruses collected from external environment and human sources in Anhui province from 2013 to 2022 belong to the same evolutionary branch, and amino acid site mutations suggest that the virus shows a tendency to gradually adapt to the mammalian host environment. Therefore, further studies on the adaptive evolution of the virus and related monitoring work are needed.

Objective:To explore the structural characteristics of intestinal microflora in children with non-alcoholic fatty liver disease（NAFLD）and the relationship between intestinal microflora and the occurrence as well as development of NAFLD in children.Methods:Fifteen children with NAFLD diagnosed at the First People's Hospital of Yunnan Province from January 2022 to December 2022 were selected as subjects，and 15 healthy children who received routine physical examinations at the outpatient clinic during the same period were randomly selected as healthy control group.The height，weight，waist circumference，blood pressure，blood biochemistry of all children were collected.At the same time，the fresh fecal samples of all children were collected，and the biological information of intestinal flora was analyzed by 16S rRNA sequencing.Results:In the NAFLD group，there were eight males and seven females，with an average age of（11.13±1.77）years.In healthy control group，there were seven males and eight females，with an average age of（9.73±2.25）years.There were no significant differences in sex，age，blood pressure between two groups.Compared with the healthy control group，the levels of body mass index，waist circumference，waist-to-height ratio，alanine aminotransferase，aspartate transaminase，gamma-glutamyl transpeptidase，total bilirubin，direct bilirubin，unconjugated bilirubin，low density lipoprotein cholesterol，uric acid and serum insulin significantly increased and high density lipoprotein cholesterol significantly decreased in NAFLD group（ P<0.05）.The results of species diversity analysis showed that chaol index and observed-species index in NAFLD group were significantly higher than those in healthy control group（ P<0.05）.Species diversity analysis showed that the species with increased abundance in NAFLD group included：Proteobacteria，Gammaproteobacteria，Enterobacteriaceae，Klebsiella，Escherichia-Shigella，Escherichia-Shigella-unclassified.Differential species with increased abundance in the healthy control group included：Bifidobacterium species，Bifidobacterium，Bifidobacteriaceae，Bifidobacteriales，Actinobacteria，Actinobacteriota，Bacteroidia，Bacteroidales，Streptococcus-thermophilus. Conclusion:There are metabolic abnormalities and obvious changes in the structure of intestinal flora in children with NAFLD.Exogenous supplementation of Bifidobacterium，Streptococcus thermophilus and Bacteroides may prevent the occurrence of NAFLD，delay the progression of disease and improve fat deposition in the liver.

Gut microecology is a complex ecosystem composed of gut microbiota and the host environment. It is a crucial factor for maintaining the host's health because it is closely related to various physiological functions, such as digestion, metabolism and immunity. Therefore, studying the gut microecology is essential for understanding the pathogenesis, prevention and treatment of disease. Recently, with the rapid advancement of molecular biology and bioinformatics technologies, significant progress has been made in the research of the gut microecology. In this review, the important technologies and strategies currently applied in gut microecology research are summarized for reference.

Objective To investigate the clinical features of the spectrum of upper gastrointestinal diseases in children and to provide assistance in the prevention,diagnosis and treatment of upper gastrointestinal diseases in children.Methods Clinical data of 424 children aged 2 months to 14 years who were hospitalised for gastroscopy in the paediatrics department of the First People's Hospital of Yunnan Province from January 2018 to June 2023 were collected,and retrospective analyses were performed for the children's clinical presentation,gastroscopy results,and HP infections.Results The symptoms of vomiting and diarrhea in infants were significantly different from those in preschool and school age groups(P＜0.05).The positive rate of lesions under gastroscopy was 96.46％.The main diseases found were non-atrophic gastritis(222 cases),bile reflux gastritis(42 cases),non-atrophic gastritis with erosion(30 cases),duodenitis(25 cases),reflux esophagitis(15 cases)and others(75 cases).Helicobacter pylori(HP)was detected in 300 of the 424 cases,and 105 cases were HP positive,with a detection rate of 35.00％.Conclusion Abdominal pain was the main symptom of upper gastrointestinal diseases in school-age and pre-school children.Vomiting and diarrhea were the main symptoms of upper gastrointestinal diseases in infants.There was no gender difference in HP infection,but there was a difference in age.

Objective To develop an asymmetric porous guided bone regeneration(GBR)membrane made from antibacterial zinc oxide nanoparticle(nZnO)/poly(3-hydroxybutyrate-co-4-hydroxy butyrate)copolymer(P34HB),and detect its osteogenic performance.Methods Ultrasonic dispersion technique,solvent displacement method and freeze-drying technique were used to prepare P34HB composite GBR membrane loaded with nZnO at different doses(0％,0.5％,1.0％and 1.5％).Scanning electron microscopy(SEM)and energy spectrometry(EDS)were conducted to determine the load of nZnO and observe the structure of the prepared membrane.Then MC3T3-E1 cells were implanted in a 24-well culture plate with the prepared GBR membrane pre-laid in the well.Thus the experiment included blank control group(no membrane)and groups with membranes composing 0％,0.5％,1.0％and 1.5％nZnO,respectively.CCK-8 and cell scratch assays were used to detect cell proliferation capacity and migration ability.The protein adsorption capacity of GBR membrane was detected by protein adsorption experiment.The in vitro degradation of GBR membrane was tested;the activity of alkaline phosphatase(ALP)was detected with chemical test.And calcified nodules were observed with alizzarin red staining;the antibacterial ability of GBR membranes was tested with in vitro antibacterial experiments.Results Four groups of nZnO/P34HB composite GBR membranes with 0％,0.5％,1.0％and 1.5％nZnO were successfully prepared.SEM results showed that the composite membrane was porous on one side and dense on the other side.EDS indicated the incorporation of zinc elements in the composite membrane.The results of cell proliferation assay showed that 0.5％and 1.0％nZnO/P34HB group promoted the proliferation of MC3T3-E1 cells,when compared with the blank control group and 0％and 1.5％nZnO/P34HB groups(P＜0.05).The results of cell scratch assay showed that MC3T3-E1 cells in the 0.5％nZnO/P34HB group migrated significantly over the scratch edge,with the cell mobility higher than that of the other 3 membrane groups in 48 h after culture(P＜0.01).Protein adsorption experiment displayed there was no significant difference in optical density of the 4 group of membrane,indicating that the addition of nZnO had no effect on the protein adsorption capacity of the material itself.The results of enzymatic experiment showed that though the quality of the 4 membranes was continuously decreased with elapse of time,the degradation rate was still relatively lower after 28 d of treatment.ALP staining and alizarin red staining displayed that the 0.5％nZnO/P34HB group obtained the strongest ALP activity and the largest amount of calcified nodules when compared with the other 3 groups(P＜0.01).Higher mineralization was observed in the 0％and 0.5％nZnO/P 34 HB groups than the other 2 groups(P＜0.01).The results of in vitro antibacterial experiments showed that the number of colonies in the 0.5％nZnO/P 34 HB group was significantly less than that in the blank control group and the 0％nZnO/P34HB group(P＜0.01).Conclusion Our prepared P34HB composite GBR membrane loaded with nZnO is in asymmetric porous structure,and can promote cell proliferation,facilitate cell osteogenesis and have bacteriostatic ability.

Objective:To analyze the protective effect of weight-loss based exercises on the knee joints of patients with simple obesity.Methods:This study was a randomized controlled trial, 60 patients with simple obesity who met the inclusion and exclusion criteria and treated at the Affiliated Panyu Central Hospital of Guangzhou Medical University from April 2021 to April 2022 were selected as subjects. The patients were randomly divided into a power bicycle group (weight-loss, 30 cases) and a moving treadmill training group (non-weight-loss, 30 cases) using the random envelope method. High intensity interval exercise training was conducted in the hospital: slow warm-up for 1 minute, followed by rapid exercise for 3 minutes, and then rest for 1 minute. Repeated this cycle twice to form one set, and to perform 3 sets per session, 5 times per week, for a continuous training of 12 weeks. In addition, patients were not allowed to participate in other sports activities, and they should maintain their original dietary habits and patterns unchanged. Body mass index and body fat percentage were measured before and after treatment, and the cases with knee pain were recorded. The volume of knee cartilage was measured using magnetic resonance imaging. The local skin temperature of the knee was measured using an electronic thermometer before and after each training session. The t-tests, Pearson-tests and Mann-Whitney U tests were used to compare the differences in the above indicators between two groups before and after intervention to analyze the protective effect of weight-loss based exercise on the knee joints of patients with simple obesity. Results:There was no statistically significant difference in baseline data such as gender, age, height, and weight between the two groups before the intervention (all P>0.05). After the intervention, the body mass index, percentage of body fat, and knee cartilage volume of both groups were significantly lower than before the intervention, and the incidence of knee pain and local skin temperature of knee were significantly higher than before the intervention (all P<0.001). The incidence of the knee pain, reduction in knee cartilage volume, and elevation in local skin temperature in the power cycling group were all significantly lower than those in the moving treadmill training group [16.67% vs 100%, 0.12 (0.05, 0.27) vs 1.68 (1.15, 2.21) cm 3, (0.17±0.09) vs (0.64±0.15)℃, respectively] (all P<0.001). And there was no statistically significant difference in body mass index and body fat percentage between the two groups (both P>0.05). Conclusion:The weight-loss based exercise has a protective effect on the knee joint of patients with simple obesity, which can avoid a reduction in volume of knee cartilage and elevation in local skin temperature, and reduce the occurrence of pain.

Gut microecology is a complex ecosystem composed of gut microbiota and the host environment. It is a crucial factor for maintaining the host's health because it is closely related to various physiological functions, such as digestion, metabolism and immunity. Therefore, studying the gut microecology is essential for understanding the pathogenesis, prevention and treatment of disease. Recently, with the rapid advancement of molecular biology and bioinformatics technologies, significant progress has been made in the research of the gut microecology. In this review, the important technologies and strategies currently applied in gut microecology research are summarized for reference.