Cone-beam computed tomography (CBCT) is widely used in dentistry, surgery, radiotherapy and other medical fields. However, repeated CBCT scans expose patients to additional radiation doses, increasing the risk of secondary malignant tumors. Low-dose CBCT image reconstruction technology, which employs advanced algorithms to reduce radiation dose while enhancing image quality, has emerged as a focal point of recent research. This review systematically examined deep learning-based methods for low-dose CBCT reconstruction. It compared different network architectures in terms of noise reduction, artifact removal, detail preservation, and computational efficiency, covering three approaches: image-domain, projection-domain, and dual-domain techniques. The review also explored how emerging technologies like multimodal fusion and self-supervised learning could enhance these methods. By summarizing the strengths and weaknesses of current approaches, this work provides insights to optimize low-dose CBCT algorithms and support their clinical adoption.
Cone-Beam Computed Tomography/methods* ; Deep Learning ; Humans ; Algorithms ; Image Processing, Computer-Assisted/methods* ; Radiation Dosage ; Artifacts

Autophagy is a cellular self-degradation process that maintains homeostasis and has been shown to promote tumor progression in advanced stages.Pancreatic cancer cells and the surrounding stromal cells exhibit high levels of autophagy.Therefore,targeting au-tophagy has emerged as a promising therapeutic strategy for pancreatic cancer.This review focuses on research targeting autophagy in pancreatic cancer treatment,elaborating on the roles and underlying mechanisms of autophagy in pancreatic cancer cell proliferation,metas-tasis,modulation of the tumor immune microenvironment,and drug resistance.Additional-ly,we summarize preclinical and clinical studies investigating autophagy-targeted therapies both as monotherapy and in combination with other treatments,aiming to provide new theo-retical rationale and therapeutic strategies for pancreatic cancer management.

Objective:To explore the characteristics of peripheral retinal defocus distribution in adult myopia and its relationship with refractive error.Methods:A cross-sectional study was conducted.A total of 270 myopic patients aged 18 to 46 years were enrolled at Tianjin Eye Hospital from January to March 2024.Data from the right eye were included in the analysis.Spherical power and cylindrical power were obtained using an autorefractor and the spherical equivalent (SE) was calculated.Corneal curvature parameters including flap keratometry (K1), steep keratometry (K2), and average keratometry (Km) were measured using the Pentacam anterior segment imaging analyzer.Central corneal thickness (CCT) and axial length (AL) were measured using the IOLMaster optical biometer.Peripheral defocus within a 53° area centered on the fovea was assessed using multispectral refractive topography.Based on the peripheral defocus data, the distribution patterns were classified into four types: hemilateral upturn type, saddle type, crater type, and relatively flat type.Characteristics of different tpes and their correlation with diopter were analyzed.This study followed the Declaration of Helsinki.The study protocol was reviewed and approved by the Medical Ethics Committee of Tianjin Eye Hospital (No.KY-2024020).All participants voluntarily participated and signed the informed consent form.Results:Of the different types of peripheral retinal defocus, 186 eyes (68.63%) were hemilateral upturn type, 45 eyes (16.61%) were crater type, 36 eyes (13.28%) were relatively flat type, and 3 eyes (1.11%) were saddle type.The crater type exhibited the lowest mean SE of (-6.18±1.50)D, while the relatively flat type showed the highest mean SE of (-3.88±0.87)D.There were significant differences in SE and AL among different peripheral defocus types ( F=15.469, 17.928, 3.431; all P<0.05).The hemilateral upturn type had significantly lower SE and spherical diopter than the relatively flat type, and crater type had significantly lower SE and spherical diopter compared to the hemilateral upturn type and relatively flat type significantly, and the hemilateral upturn type had longer AL than the relatively flat type (all P<0.05).There was no statistically significant difference in CCT, K1, K2, or Km among different peripheral defocus types ( F=0.861, 1.761, 2.603, 2.248; all P>0.05).Spherical power was weakly negatively correlated with superior, inferior, and temporal peripheral defocus ( r=-0.269, P<0.001; r=-0.176, P<0.01; r=-0.292, P<0.001).Age was positively correlated with superior and temporal peripheral defocus ( rs=0.213, P<0.001; rs=0.181, P=0.003), and negatively correlated with nasal peripheral defocus ( rs=-0.138, P=0.023). Conclusions:Among adult peripheral defocus patterns, the hemilateral upturn type is predominant.The crater type has the lowest mean spherical equivalent, while the relatively flat type has the highest.There are negative correlations between spherical power and the superior, inferior, and temporal peripheral defocus.

Objective:To construct a multimodal induction educational system suitable for standardized pediatric residency training bases, and to evaluate its effectiveness, thereby obtaining suggestions for further improvement.Methods:Twelve residents newly enrolled in the 2023 standardized residency training program who commenced their first-year training were included as study subjects. The induction educational system comprised multiple modules: department introduction, training plan and assessment requirements, departmental workflow, routine diagnosis and treatment of major diseases, specialized skills/procedures, and lifestyle guidance. Training materials and methods were tailored to the characteristics of each training module. Checklists were used for supervision and review, and a competency checklist was designed to evaluate residents' mastery of the training at two weeks of induction, which would guarantee the effectiveness of the training. A questionnaire survey, powered by wjx.cn, was used to obtain the experience and suggestions from the residents and ward instructors on induction education, and content ranking analysis was performed on the survey results.Results:The survey revealed that, before starting a new rotation, residents' top three educational needs were departmental workflow, routine diagnosis and treatment of common diseases, and specialized skills/procedures. Residents preferred face-to-face lectures and demonstrations by attending physicians or senior residents; instructors suggested improving relevant materials (such as resident physician manuals and video materials) and face-to-face lectures. The residents considered the current induction educational system to be greatly beneficial in basic theories, treatment principles, basic skills, and auxiliary examination processes.Conclusions:Through the above research, a multimodal induction educational system suitable for the standardized pediatric residency training base in the Peking University First Hospital has been preliminarily established, and suggestions for further improvement have been obtained, which is conducive to further improving the system and residents' post competency.

Objective:To explore the characteristics of peripheral retinal defocus distribution in adult myopia and its relationship with refractive error.Methods:A cross-sectional study was conducted.A total of 270 myopic patients aged 18 to 46 years were enrolled at Tianjin Eye Hospital from January to March 2024.Data from the right eye were included in the analysis.Spherical power and cylindrical power were obtained using an autorefractor and the spherical equivalent (SE) was calculated.Corneal curvature parameters including flap keratometry (K1), steep keratometry (K2), and average keratometry (Km) were measured using the Pentacam anterior segment imaging analyzer.Central corneal thickness (CCT) and axial length (AL) were measured using the IOLMaster optical biometer.Peripheral defocus within a 53° area centered on the fovea was assessed using multispectral refractive topography.Based on the peripheral defocus data, the distribution patterns were classified into four types: hemilateral upturn type, saddle type, crater type, and relatively flat type.Characteristics of different tpes and their correlation with diopter were analyzed.This study followed the Declaration of Helsinki.The study protocol was reviewed and approved by the Medical Ethics Committee of Tianjin Eye Hospital (No.KY-2024020).All participants voluntarily participated and signed the informed consent form.Results:Of the different types of peripheral retinal defocus, 186 eyes (68.63%) were hemilateral upturn type, 45 eyes (16.61%) were crater type, 36 eyes (13.28%) were relatively flat type, and 3 eyes (1.11%) were saddle type.The crater type exhibited the lowest mean SE of (-6.18±1.50)D, while the relatively flat type showed the highest mean SE of (-3.88±0.87)D.There were significant differences in SE and AL among different peripheral defocus types ( F=15.469, 17.928, 3.431; all P<0.05).The hemilateral upturn type had significantly lower SE and spherical diopter than the relatively flat type, and crater type had significantly lower SE and spherical diopter compared to the hemilateral upturn type and relatively flat type significantly, and the hemilateral upturn type had longer AL than the relatively flat type (all P<0.05).There was no statistically significant difference in CCT, K1, K2, or Km among different peripheral defocus types ( F=0.861, 1.761, 2.603, 2.248; all P>0.05).Spherical power was weakly negatively correlated with superior, inferior, and temporal peripheral defocus ( r=-0.269, P<0.001; r=-0.176, P<0.01; r=-0.292, P<0.001).Age was positively correlated with superior and temporal peripheral defocus ( rs=0.213, P<0.001; rs=0.181, P=0.003), and negatively correlated with nasal peripheral defocus ( rs=-0.138, P=0.023). Conclusions:Among adult peripheral defocus patterns, the hemilateral upturn type is predominant.The crater type has the lowest mean spherical equivalent, while the relatively flat type has the highest.There are negative correlations between spherical power and the superior, inferior, and temporal peripheral defocus.

Objective:To construct a multimodal induction educational system suitable for standardized pediatric residency training bases, and to evaluate its effectiveness, thereby obtaining suggestions for further improvement.Methods:Twelve residents newly enrolled in the 2023 standardized residency training program who commenced their first-year training were included as study subjects. The induction educational system comprised multiple modules: department introduction, training plan and assessment requirements, departmental workflow, routine diagnosis and treatment of major diseases, specialized skills/procedures, and lifestyle guidance. Training materials and methods were tailored to the characteristics of each training module. Checklists were used for supervision and review, and a competency checklist was designed to evaluate residents' mastery of the training at two weeks of induction, which would guarantee the effectiveness of the training. A questionnaire survey, powered by wjx.cn, was used to obtain the experience and suggestions from the residents and ward instructors on induction education, and content ranking analysis was performed on the survey results.Results:The survey revealed that, before starting a new rotation, residents' top three educational needs were departmental workflow, routine diagnosis and treatment of common diseases, and specialized skills/procedures. Residents preferred face-to-face lectures and demonstrations by attending physicians or senior residents; instructors suggested improving relevant materials (such as resident physician manuals and video materials) and face-to-face lectures. The residents considered the current induction educational system to be greatly beneficial in basic theories, treatment principles, basic skills, and auxiliary examination processes.Conclusions:Through the above research, a multimodal induction educational system suitable for the standardized pediatric residency training base in the Peking University First Hospital has been preliminarily established, and suggestions for further improvement have been obtained, which is conducive to further improving the system and residents' post competency.

Autophagy is a cellular self-degradation process that maintains homeostasis and has been shown to promote tumor progression in advanced stages.Pancreatic cancer cells and the surrounding stromal cells exhibit high levels of autophagy.Therefore,targeting au-tophagy has emerged as a promising therapeutic strategy for pancreatic cancer.This review focuses on research targeting autophagy in pancreatic cancer treatment,elaborating on the roles and underlying mechanisms of autophagy in pancreatic cancer cell proliferation,metas-tasis,modulation of the tumor immune microenvironment,and drug resistance.Additional-ly,we summarize preclinical and clinical studies investigating autophagy-targeted therapies both as monotherapy and in combination with other treatments,aiming to provide new theo-retical rationale and therapeutic strategies for pancreatic cancer management.

Background and purpose:For patients with human epidermal growth factor receptor 2(HER2)-positive metastatic breast cancer,trastuzumab treatment can prolong the overall survival and significantly improve the prognosis of patients.However,the reference original research trastuzumab(Herceptin?)is more expensive.Biosimilars have comparable efficacy and safety profiles while increasing patient access to treatment.This clinical trial aimed to evaluate the efficacy,pharmacokinetics,safety and immunogenicity of the trastuzumab biosimilar AK-HER2 compared to trastuzumab(Herceptin?)in patients with HER2-positive metastatic breast cancer.Methods:This multi-center,randomised,double-blind phase Ⅲ clinical trial was conducted in 43 subcenters in China.This study complied with the research protocol,the ethical principles stated in the Declaration of Helsinki and the quality management standards for drug clinical trials.It was approved by the hospital's medical ethics committee.The clinical trial registration agency is the State Food and Drug Administration(clinical trial approval number:2015L04224;clinical trial registration number:CTR20170516).Written informed consent was obtained from subjects before enrollment.Enrolled patients were randomly assigned to the AK-HER2 group and the control group,respectively receiving AK-HER2 or trastuzumab(initial loading dose 8 mg/kg,maintenance dose 6 mg/kg,every 3 weeks as a treatment cycle,total treatment time is 16 cycles)in combination with docetaxel(75 mg/m2,treatment duration is at least 9 cycles).The primary endpoint of this clinical trial was the objective response rate(ORR9)between the AK-HER2 group and the control group in the 9th cycle.Secondary efficacy endpoints included ORR16,disease control rate(DCR),clinical benefit rate(CBR),progression-free survival(PFS)and 1-year survival rate.In this study,100 subjects(AK-HER2 group to control group=1:1)were randomly selected for blood sample collection after the 6th cycle of medication,The collection time points were 45 minutes after infusion(the end of administration),4,8,24,72,120,168,336,and 504 hours after the end of administration.After collection,blood samples were analyzed by PK parameter set(PKPS).Other evaluation parameters included safety and immunogenicity assessment.Results:A total of 550 patients with HER2-positive metastatic breast cancer were enrolled in this clinical trial between Sep.2017 and Mar.2021.In the AK-HER2 group(n=237),129 subjects in the experimental group achieved complete response(CR)or partial response(PR),and the ORR9 was 54.4%.There were 134 subjects in the control group(n=241)who achieved CR or PR,and the ORR9 was 55.6%.The ORR9 ratio between the AK-HER2 group and the control group was 97.9%[90%confidence interval(CI):85.4%-112.2%,P=0.784],which was not statistically significant.In all secondary efficacy endpoints,no statistically significant differences were observed between the two groups.We conducted a mean ratio analysis of pharmacokinetics(PK)parameters between the AK-HER2 group and the control group,and the results suggested that the pharmacokinetic characteristics of the two drugs are similar.The incidence of treatment emergent adverse event(TEAE)leading to drug reduction or suspension during trastuzumab treatment was 3.6%(10 cases)in the AK-HER2 group and 8.1%(22 cases)in the control group.There was statistically significant difference between the two groups(P=0.027).The incidence rate was significantly lower in the AK-HER2 group than in the control group,and there was no statistically significant difference among the other groups.The differences in the positive rates of anti-drug antibodies(ADA)and neutralizing antibodies(NAB)between groups were of no statistical significance(P=0.385 and P=0.752).Conclusion:In patients with HER2-positive metastatic breast cancer,AK-HER2 was comparable to the trastuzumab(Herceptin?)in terms of drug efficacy,pharmacokinetics,safety and immunogenicity.

ObjectiveTo explore the impact of the interaction between occupational and non-occupational noise exposure on the risk of high-frequency hearing loss (HFHL) in noise-exposed workers. Methods A total of 602 male workers with normal hearing, engaged in an automobile manufacturing company between 2016 and 2018, were selected as the study subjects using the retrospective cohort study method. Pure-tone audiometry and questionnaire surveys were conducted on the workers. The Kaplan-Meier survival analysis and multivariate Cox proportional hazards regression model were used to analyze the interaction between occupational and non-occupational noise exposure and the risk of HFHL in these workers. Results The prevalence of HFHL of the workers was 34.1% in 2020, without any cases of speech frequency hearing loss. Kaplan-Meier survival analysis result showed that the risk of HFHL increased in workers with excessive national occupational noise exposure intensity, self-reported noisy living environments, and both excessive national occupational noise exposure intensity and self-reported noisy living environments (all P<0.01). The results of the Cox proportional hazards model showed that the combined effect of excessive national occupational noise exposure intensity and self-reported noisy living environments [relative risk (RR)=2.40, P<0.01] was higher than the individual effects of excessive national occupational noise exposure intensity (RR=2.09, P<0.01) and self-reported noisy living environments (RR=2.39, P<0.01). There was an antagonistic effect between excessive national occupational noise exposure intensity and self-reported noisy living environments (interaction index <1.00). Conclusion Both occupational and non-occupational noise exposure can increase the risk of HFHL in noise-exposed workers, and there is an interaction between them.