Purpose: X-ray scattering adversely affects cone-beam computed tomography (CBCT) image quality, generating image artifacts, causing inaccurate tissue density representation, and reducing contrast. This study evaluated the performance of a 2-dimensional antiscatter grid (2D grid) prototype in a dental CBCT system. Materials and Methods: A focused 2D grid prototype was fabricated from tungsten and integrated with the detector of a dental CBCT system. Residual scatter transmitted through the 2D grid was corrected using a measurement-based scatter correction method. Phantom imaging experiments were performed in anatomical regions relevant to dentaland head imaging with and without this grid. Following image reconstruction via filtered back projection, attenuation coefficients were converted to Hounsfield units (HU). Subsequently, scatter suppression performance, HU consistency, image artifacts, and contrast resolution were evaluated. Results: The 2D grid reduced scatter intensity by a factor of 10-20 in CBCT projections. Consequently, the grid substantially increased contrast, reduced image artifacts, and improved HU consistency. The contrast increased by 27% and 48% in bone- and soft tissue-equivalent regions, respectively. HU value deviations among teeth decreasedfrom 510 to 146 HU. These results indicate improved visualization and tissue density representation fidelity in CBCTimages acquired with the 2D grid. Conclusion Use of a 2D grid could substantially improve the accuracy of tissue density representation and the contrast of dental and head anatomy in 3-dimensional images obtained with dental CBCT. Such improvements may translate to better quantitative evaluation of bone quality, enhanced tissue visualization, and more accurate model generation for surgical planning and guidance.

Purpose: X-ray scattering adversely affects cone-beam computed tomography (CBCT) image quality, generating image artifacts, causing inaccurate tissue density representation, and reducing contrast. This study evaluated the performance of a 2-dimensional antiscatter grid (2D grid) prototype in a dental CBCT system. Materials and Methods: A focused 2D grid prototype was fabricated from tungsten and integrated with the detector of a dental CBCT system. Residual scatter transmitted through the 2D grid was corrected using a measurement-based scatter correction method. Phantom imaging experiments were performed in anatomical regions relevant to dentaland head imaging with and without this grid. Following image reconstruction via filtered back projection, attenuation coefficients were converted to Hounsfield units (HU). Subsequently, scatter suppression performance, HU consistency, image artifacts, and contrast resolution were evaluated. Results: The 2D grid reduced scatter intensity by a factor of 10-20 in CBCT projections. Consequently, the grid substantially increased contrast, reduced image artifacts, and improved HU consistency. The contrast increased by 27% and 48% in bone- and soft tissue-equivalent regions, respectively. HU value deviations among teeth decreasedfrom 510 to 146 HU. These results indicate improved visualization and tissue density representation fidelity in CBCTimages acquired with the 2D grid. Conclusion Use of a 2D grid could substantially improve the accuracy of tissue density representation and the contrast of dental and head anatomy in 3-dimensional images obtained with dental CBCT. Such improvements may translate to better quantitative evaluation of bone quality, enhanced tissue visualization, and more accurate model generation for surgical planning and guidance.

Purpose: X-ray scattering adversely affects cone-beam computed tomography (CBCT) image quality, generating image artifacts, causing inaccurate tissue density representation, and reducing contrast. This study evaluated the performance of a 2-dimensional antiscatter grid (2D grid) prototype in a dental CBCT system. Materials and Methods: A focused 2D grid prototype was fabricated from tungsten and integrated with the detector of a dental CBCT system. Residual scatter transmitted through the 2D grid was corrected using a measurement-based scatter correction method. Phantom imaging experiments were performed in anatomical regions relevant to dentaland head imaging with and without this grid. Following image reconstruction via filtered back projection, attenuation coefficients were converted to Hounsfield units (HU). Subsequently, scatter suppression performance, HU consistency, image artifacts, and contrast resolution were evaluated. Results: The 2D grid reduced scatter intensity by a factor of 10-20 in CBCT projections. Consequently, the grid substantially increased contrast, reduced image artifacts, and improved HU consistency. The contrast increased by 27% and 48% in bone- and soft tissue-equivalent regions, respectively. HU value deviations among teeth decreasedfrom 510 to 146 HU. These results indicate improved visualization and tissue density representation fidelity in CBCTimages acquired with the 2D grid. Conclusion Use of a 2D grid could substantially improve the accuracy of tissue density representation and the contrast of dental and head anatomy in 3-dimensional images obtained with dental CBCT. Such improvements may translate to better quantitative evaluation of bone quality, enhanced tissue visualization, and more accurate model generation for surgical planning and guidance.

Objective To comprehensively understand the dynamic transcriptional landscape during infection through investigating the temporal molecular changes in macrophages RAW 264.7 upon infection with Salmonella typhimurium SL1344.Methods Macrophages RAW 264.7 were infected with Salmonella typhimurium SL1344,and cell samples were collected at 0 h,8 h,and 16 h for RNA-sequencing(RNA-seq).Upstream and downstream analyses of the transcriptome data including differential gene expression,clustering,functional annotation,and mo-lecular network studies were conducted to elucidate the signaling pathways changes in macrophages.Results Infec-ted macrophages exhibited significant morphological and transcriptional changes.Differential gene analysis identified significant upregulation and downregulation patterns.Clustering revealed six gene clusters involving various signaling pathways,such as immune response,membrane transport,and lipid catabolic process.Conclusions Macrophages dynamically respond to Salmonella typhimurium infection,displaying distinct temporal gene expression patterns.The coordinated activation of immune response,membrane transport,and lipid catabolic process pathways implies a multifaceted cellular adaptation to external infections,providing essential insights into the molecular mechanisms of macrophage response to Salmonella typhimurium infection.

Objective To evaluate the therapeutic effect of poloxamer hydrogel loaded with exosomes derived from human dental pulp stem cells genetically modified with human hepatocyte growth factor against radiation skin injuries.Methods Human dental pulp stem cells derived exosomes(DPSC-Exo)and hepatocyte growth factor modified DPSC-Exo(HGF-DPSC-Exo)were extracted via ultracentrifugation separation,identified in terms of particle size and morphology,and analyzed separately by means of nanoparticle tracking analysis and scanning electron microscopy(SEM),while exosome marker proteins were determined by Western blot.Then,the effect of exosomes on radiation-damaged skin cells was assessed.The poloxamer hydrogel was prepared and its safety was evaluated with CCK-8.A mouse model of injury combined with radiation injury was established,and the therapeutic effect of hydrogel loaded with exosomes was determined based on wound size,HE and Masson staining.Furthermore,the underlining therapeutic mechanism was explored with Tunnel assay,malondialdehyde content and peroxidase activity.Results The diameter exosomes ranged from 30 to 150 nm and their morphology was a disc-shaped vesicle under SEM.Moreover,CD9,CD63 and TSG101 were expressed.The results of cellular experiments showed that exosomes significantly promoted the proliferation and migration of radiation-damaged skin keratinocytes and fibroblasts,and reduced their apoptosis.HGF modification enhanced the healing effect of exosomes.Poloxamer hydrogel showed good temperature-sensitive properties and biocompatibility.The results of animal experiments showed that exosomes significantly accelerated the healing of radiation-combined injuries in mice,inhibited inflammatory infiltration and mitigated collagen deposition in the wound.Interestingly,the healing effect in the group treated with hydrogel loaded with exosomes was the best.The underlining mechanism was possibly related to promotion of cell proliferation and inhibition of apoptosis and oxidative stress.Conclusion A novel poloxamer hydrogel loaded HGF-DPSC-Exo has been prepared and its therapeutic effect against radiation combined injury has been proved,thus providing a new strategy for the treatment of radiation skin injury in clinic.

Objective:To select the differential prognostic lactic acid metabolism-related genes(LRGs)of the head and neck squamous cell carcinoma(HNSCC)to construct the LRGs prognostic model of HNSCC,and to clarify the potential mechanism.Methods:The HNSCC gene expression and clinical data were obtained from The Cancer Genome Atlas(TCGA)and Gene Expression Omnibus(GEO)Databases,the LRGs were identified through GeneCards Database,and R software was used to screen out the LRGs of HNSCC;univariate Cox regression analysis was used to identify prognosis-related genes;two different subtypes were identified based on the prognostis-related LRGs;Kaplan-Meier(K-M)curve analysis was used to compare the prognosis of the patients between two groups;CIBERSORT algorithm was used to perform the immuno-correlation analysis between two groups;multivariate Cox regression analysis and LASSO regression analysis were used to construct the prognostic model;receiver operating characteristic curve(ROC)and K-M survival curve were used to assess the relationship between LRGs and survival and prognosis of the HNSCC patients.The prognostic model was validated by GSE27020,GSE41613,and GSE65858 datasets.The experiment were grouped based on risk score,and immune-related analysis and tumor score analysis were performed.Results:The TCGA Database differential analysis results showed that 1 196 LRGs were identified from HNSCC samples;univariate Cox regression analysis selected 27 differentially expressed genes(DEGs)associated with the prognosis of the HNSCC patients.Two different LRGs subtypes(Group 1 and Group 2)were identified according to the prognosis-related genes.The K-M survival curves results showed that the overall survival(OS)of the patients in Group 2 was significantly higher than that in Group 1,and the immune cell expression amount of the patients in Group 2 was also higher than that in group 1.The multivariate Cox regression and LASSO regression analysis results screened out 9 LRGs,including hypoxanthine phosphoribosyltransferase 1(HPRT1),amyloid precursor protein(APP),glycogen phosphorylase L(PYGL),urokinase-type plasminogen activator(PLAU),cannabinoid receptor 2(CNR2),stanniocalcin 2(STC2),nucleotide binding oligomerization domain-like receptor protein 1(NLRP1),integrin-linked kinase(ILK),and forkhead box B1(FOXB1);the prognostic model was constructed.The K-M and ROC curve results indicated that the expression levels of above 9 genes were associated with the survival and prognosis of the HNSCC patients,providing good 1-year,2-year,and 3-year survival prediction effect,and the area under ROC curve(AUC)values were all greater than 0.650.Furthermore,the predictive ability of the prognosis model was validated in GSE27020,GSE41613,and GSE65858 datasets.The patients classified based on the risk scores had distinguishable immune statuses.Conclusion:The differentially expressed LRGs of HNSCC screened by bioinformatics methods are related to the survival and prognosis of the HNSCC patients;the prognostic model constructed by 9 LRGs can predict the survival status and treatment response of the HNSCC patients.

BACKGROUND:Skin damage caused by radiation therapy and nuclear accidents is still a serious medical problem.It is difficult to achieve effective treatment results with single prevention and treatment methods.It is an important research direction to find new comprehensive treatment methods. OBJECTIVE:To observe the protective effect and the underlying mechanism of 1,2-propanediol combined with hepatocyte growth factor-modified exosomes derived from dental pulp stem cells on human epidermal radiation damage cell models. METHODS:(1)After infection of human dental pulp stem cells using recombinant adenovirus of human hepatocyte growth factor gene,exosomes,i.e.,Ad.HGF DPSC-Exo,were isolated with ultracentrifugation.(2)HaCat cells were irradiated with X-ray.The cells were treated with 1,2-propanediol before irradiation and Ad.HGF DPSC-Exo after irradiation.Cell proliferative activity was determined by CCK-8 assay.Cell apoptosis was detected by flow cytometry.Cell migration was detected by cell scratch assay.The expression levels of P21 and P53 were detected by PCR. RESULTS AND CONCLUSION:1,2-Propanediol,Ad.HGF.DPSC-Exo,Ad.HGF.DPSC-Exo + 1,2-propanediol could significantly improve the growth inhibition of HaCaT cells,reduce cell apoptosis,elevate cell proliferation and migration,and exhibit a good radiation protection effect.Moreover,the combined effect of Ad.HGF.DPSC-Exo + 1,2-propanediol was better.Furthermore,Ad.HGF.DPSC-Exo + 1,2-propanediol alleviated the cellular G2/M phase block and decreased the expression of cell cycle genes P53 and P21.In conclusion,1,2-propanediol pretreatment combined with Ad.HGF.DPSC-Exo had significant protective effects on radiation-induced HaCaT cell injury and it provided novel ideas and potential methods for the prevention and treatment of radiation-induced skin damage.

OBJECTIVE To study the protective effect and possible mechanism of soybean isoflavones against threatened miscarriage rats. METHODS Female mice were selected to promote estrus and mate with male mice. After pregnancy， they were randomly divided into normal group （purified water， i.g.， n＝10）， model group （purified water， i.g.， n＝9）， positive control drug group （progesterone 4 mg/kg， i.m.， n＝9）， low-， medium- and high-dose soybean isoflavone groups （25， 50 and 100 mg/kg， i.g.， n＝10）. Except for the normal group， the rest were given mifepristone+misoprostol on the 8th day of pregnancy to establish threatened miscarriage model， and then given purified water or drugs， once a day， on days 1-7 and 9-12 of pregnancy， respectively. At 14 days of pregnancy， the rates of fetal protection were counted. Serum levels of β-human chorionic gonadotrophin （β-HCG） and progesterone （P） in rats were detected. Pathological and morphological changes in rat placenta and decidua tissues were observed， and the apoptosis indexes of cells were detected； mRNA and protein expressions of factor of apoptosis related （Fas）， factor of apoptosis related ligand （FasL）， proliferating cell nuclear antigen （PCNA） and heparin binding epidermal growth factor （HB-EGF） were determined in placenta tissues， and mRNA and protein expressions of Fas， PCNA and HB-EGF in decidua tissues were detected. RESULTS In the model group， the placental tissues of rats were hyperemia and dilatation， with fewer and irregular blood vessels； severe stromal edema，inflammatory cell infiltration and iron-choledrin depositionwere observed. Compared with model group， the fetal survival rates， serum levels of β-HCG and P， the expressions of PCNA and HB-EGF mRNA and proteins in the placenta and decidua tissue of soybean isoflavone groups increased significantly （P＜ 0.05）， while pathological changes were improved significantly； cell apoptosis index in the placenta and decidua tissue， the expressions of Fas， FasL mRNA and proteins in the placenta and Fas mRNA and protein in the decidua tissue decreased significantly （P＜0.05）. The effect of soybean isoflavones was dose-dependent （P＜0.05）. CONCLUSIONS Soybean isoflavone has protective effect on threatened miscarriage， the mechanism of which is related to down-regulating the expressions of Fas and FasL mRNA and protein at the maternal-fetal interface， and up-regulating the expressions of mRNA and protein of PCNA and HB- EGF.

ObjectiveTo compare the difference in adverse reactions after oxaliplatin-containing chemotherapy between colorectal cancer patients with or without spleen-kidney yang deficiency syndrome. MethodsA retrospective study was conducted using the electronic medical records of Beijing Hospital of Traditional Chinese Medicine， Capital Medical University. A total of 483 colorectal cancer patients from January 1， 2009 to December 31， 2022 were selected. Patients were divided into two groups based on their syndrome types， that was spleen-kidney yang deficiency syndrome （SKYDS） group （130 cases） and non-SKYDS group （353 cases）. The incidence of adverse reactions including gastrointestinal reactions， liver damage， bone marrow suppression， and peripheral neurotoxicity after completing 2， 4， 6， and more than 6 cycles of chemotherapy was compared between the two groups. Univariate and multivariate logistic regression analyses were used to analyze the associations of age， gender， alcohol history， primary tumor location， tumor differentiation， tumor staging， chemotherapy courses， and syndrome types with the occurrence of gastrointestinal adverse reactions， liver function damage， bone marrow suppression and peripheral neurotoxicity in colorectal cancer patients who have completed 2， 4， 6 and more than 6 cycles of oxaliplatin-containing chemotherapy. ResultsThere were significant differences in the occurrence of gastrointestinal reactions after completing 2， 4， 6 and more than 6 cycles of chemotherapy between the two groups （P＜0.01）， with much more severe conditions in SKYDS group than non-SKYDS group （P＜0.01）. There was no significant difference in liver function damage and bone marrow suppression between groups （P＞0.05）. There were statistically significant differences in the occurrence of peripheral neurotoxicity after completion of 2 cycles （P=0.044）， 4 cycles （P=0.002） and more than 6 cycles （P＜0.001） of chemothe-rapy， with higher rate in SKYDS group than the non-SKYDS group （P＜0.05）. Univariate analysis showed that female， patients with stage Ⅲ tumors and patients having completed ≥ 6 cycles of chemotherapy had a higher incidence of bone marrow suppression （P＜0.05）， and patients with SKYDS had a higher incidence of gastrointestinal reactions （P＜0.001）. Patients with a history of drinking， stage Ⅳ cancer， and ≥6 cycles of chemotherapy had a higher incidence of liver function injury （P＜0.05）. Patients with stage Ⅲ cancer， ≥6 cycles of chemotherapy， and SKYDS had a higher incidence of peripheral neurotoxicity （P＜0.05）. Multivariate analysis showed that the risk factor for bone marrow suppression was chemotherapy ≥6 cycles （P=0.001）， and SKYDS was the risk factor for gastrointestinal reaction （P＜0.001）. The risk factor for liver function damage was tumor stage Ⅳ （P=0.001） and SKYDS （P=0.039）. All variables had no significant correlation with the occurrence of peripheral neurotoxicity. ConclusionFor colorectal cancer patients， being diagnosed with SKYDS is a risk factor for developing gastrointestinal adverse reactions and peripheral neurotoxicity following chemotherapy with an oxaliplatin-based regimen.

There are more than 1 billion patients worldwide suffering from hepatobiliary diseases, yet there remains a scarcity of successful practices and frameworks in standardizing, inte-grating, and sharing disease data. In response to this challenge, Beijing Tsinghua Changgung Hospital affiliated to Tsinghua University, in collaboration with various medical and information technology institutions, has developed the 'Blockchain-Based Hepatobiliary Disease Data Extraction and Exchange' standard. This standard, known as the IEEE 3806-2023 standard, is establishing China′s first inter-national standard for the application of hepatobiliary disease data. The authors elucidate the origins, application scope, key contents, and clinical significance of this standard, with the aim of aiding medical establishments, pharmaceutical companies, and other stakeholders in comprehending the data extraction and exchange standard for hepatobiliary diseases, thereby facilitating its wider adop-tion and implementation.