1.Compact Fundus Imaging System Using Shack-Hartmann Wavefront Sensing for High-speed Auto-focus
Zhe-Kai LIN ; Long CHEN ; Geng-Yong ZHENG ; Jin-Tian HUANG ; Jia-Xin DONG ; Shang-Pan YANG ; Wen-Zheng DING ; Ding-An HAN ; Xue-Hua WANG ; Ya-Guang ZENG
Progress in Biochemistry and Biophysics 2026;53(4):1076-1086
ObjectiveThe widespread adoption of portable fundus cameras for primary care and community screening is hindered by limitations in current autofocus(AF) technologies. Image-based methods relying on sharpness evaluation require iterative searches, resulting in slow convergence, while projection-based techniques are susceptible to optical artifacts and calibration errors. To address these challenges, this study introduces a novel AF system based on direct wavefront sensing, designed to deliver simultaneous high speed, high precision, and operational robustness within the compact form factor essential for portable ophthalmic devices. MethodsOur approach fundamentally reimagines the AF process by directly measuring the ocular wavefront aberration. We developed a custom portable fundus camera integrating a miniaturized Shack-Hartmann wavefront sensor (SHWS) into the optical path. An 850 nm laser diode projects a point source onto the retina via oblique illumination to minimize corneal reflections. Light scattered from this spot carries the eye’s refractive error through the imaging optics and is directed to the SHWS, positioned at a plane optically conjugate to the primary color CMOS imaging sensor. A microlens array within the SHWS samples the incident wavefront, generating a pattern of focal spots on a CCD. Real-time centroid analysis of these spots provides a map of local wavefront slopes. These measurements are processed through a singular value decomposition (SVD) algorithm to fit a Zernike polynomial basis set, enabling real-time reconstruction of the wavefront phase. The defocus component (S) is extracted from the second-order Zernike coefficients, providing a direct, quantitative measure of the refractive error in diopters. This value serves as a precise error signal in a closed-loop control system, which commands a voice-coil actuated focusing lens to its null position in a single, deterministic step, eliminating the need for iterative search algorithms. ResultsComprehensive evaluation demonstrated the system’s high performance. Testing on a calibrated model eye (OEMI-7) established a highly linear relationship between the computed defocus S and the focusing lens position across a ±20 Diopter (D) compensation range, achievable within a 5 mm mechanical travel. The system achieved a focusing precision of 0.08 D, corresponding to an 18-fold improvement over a conventional projection spot-size method tested under identical conditions. The total focus acquisition time, encompassing wavefront measurement, computation, and lens actuation, averaged under 0.5 s. Clinical validation with 25 human volunteers (50 eyes, refractive range -15 D to +10 D) confirmed practical efficacy. The wavefront-sensing AF succeeded in 92% of attempts with a mean time of 0.5 s, substantially outperforming a projection-based benchmark which achieved only a 32% success rate with an average time of 4.25 s. The system provided instantaneous directional guidance and maintained stability during minor ocular movements. Objective assessment of image quality, via amplitude contrast of retinal vasculature, showed consistent and significant enhancement following AF correction across the entire tested diopter range. ConclusionThis work successfully implements and validates a direct wavefront-sensing autofocus paradigm for portable fundus cameras. By directly quantifying and compensating for the optical defocus aberration, this method bypasses the fundamental limitations of image-processing and projection-based techniques, enabling rapid, precise, and deterministic diopter compensation. The developed system delivers an exceptional combination of a wide operational range (±20 D), high accuracy (0.08 D), fast convergence (0.5 s), and a compact physical footprint. This technology provides a practical and high-performance focusing solution capable of enhancing the reliability, throughput, and diagnostic utility of portable retinal imaging in large-scale screening applications. Future efforts will be directed towards system cost optimization and performance adaptation for diverse ocular conditions.
2.Evaluation of FTA-LAMP direct extraction method for extracting DNA from Streptococcus mutans
Yuehui WANG ; Jin SHANG ; Chen YANG ; Dongge FU ; Can CAO ; Xiaodong ZHANG ; Jingfu WANG
Chinese Journal of Tissue Engineering Research 2025;29(5):1043-1049
BACKGROUND:Streptococcus mutans is an important pathogen of dental caries,and timely detection of its levels is of great significance for early detection and treatment of dental caries. OBJECTIVE:To evaluate the effect of loop-mediated isothermal amplification(FTA-LAMP)direct extraction of Streptococcus mutans DNA. METHODS:(1)Bacterial suspensions containing ATCC standard strains(Streptococcus mutans)were prepared and inoculated into the brain-heart leachate medium.After mixed thoroughly,the mixture was then diluted in a 10-fold gradient into seven concentrations(4.2×107,4.2×106,4.2×105,4.2×104,4.2×103,4.2×102,4.2×10 CFU/mL),two parallel controls were made for each dilution level,and sterile water was used as a blank control.(2)The DNA of Streptococcus mutans was extracted using FTA Elute card,boiling method,kit extraction and lysate extraction methods separately and then amplified using LAMP technology was amplified.A specificity test was also performed to compare the differences between the four DNA extraction methods.RESULTS AND CONCLUSION:The DNA extracted by all four methods met the requirements for LAMP amplification.Specificity test results showed that only Streptococcus mutans could specifically amplify the target gene.The detection limit value of the DNA concentration was 4.2×103 CFU/mL for the lysate method,4.2×104 CFU/mL for the FTA Elute card extraction method,4.2×106 CFU/mL for the kit extraction method,and 4.2×107 CFU/mL for the boiling method.In the other aspects of the four extraction methods,the kit extraction method had the highest experimental cost,number of steps and time;the other three methods had the same number of steps,with the FTA Elute card method requiring the least amount of instruments,the boiling method having the lowest single cost,and the lysate extraction method taking the least amount of time.Only a small amount of bacteria were needed for successful extraction using both the FTA Elute card and lysate extraction methods.Compared with the FTA Elute card method,the lysate extraction method was superior in terms of time,but it had a high single cost and required more equipment.To conclude,the FTA-LAMP technology established in this study has the advantages of ease of operation,high specificity,high sensitivity,and visualization,which is expected to be a new way for efficient extraction and detection of Streptococcus mutans.
3.Role and mechanism of platelet-derived growth factor BB in repair of growth plate injury
Hongcheng PENG ; Guoxuan PENG ; Anyi LEI ; Yuan LIN ; Hong SUN ; Xu NING ; Xianwen SHANG ; Jin DENG ; Mingzhi HUANG
Chinese Journal of Tissue Engineering Research 2025;29(7):1497-1503
BACKGROUND:In the initial stage of growth plate injury inflammation,platelet-derived growth factor BB promotes the repair of growth plate injury by promoting mesenchymal progenitor cell infiltration,chondrogenesis,osteogenic response,and regulating bone remodeling. OBJECTIVE:To elucidate the action mechanism of platelet-derived growth factor BB after growth plate injury. METHODS:PubMed,VIP,WanFang,and CNKI databases were used as the literature sources.The search terms were"growth plate injury,bone bridge,platelet-derived growth factor BB,repair"in English and Chinese.Finally,66 articles were screened for this review. RESULTS AND CONCLUSION:Growth plate injury experienced early inflammation,vascular reconstruction,fibroossification,structural remodeling and other pathological processes,accompanied by the crosstalk of chondrocytes,vascular endothelial cells,stem cells,osteoblasts,osteoclasts and other cells.Platelet-derived growth factor BB,as an important factor in the early inflammatory response of injury,regulates the injury repair process by mediating a variety of cellular inflammatory responses.Targeting the inflammatory stimulation mediated by platelet-derived growth factor BB may delay the bone bridge formation process by improving the functional activities of osteoclasts,osteoblasts,and chondrocytes,so as to achieve the injury repair of growth plate.Platelet-derived growth factor BB plays an important role in angiogenesis and bone repair tissue formation at the injured site of growth plate and intrachondral bone lengthening function of uninjured growth plate.Inhibition of the coupling effect between angiogenesis initiated by platelet-derived growth factor BB and intrachondral bone formation may achieve the repair of growth plate injury.
4.Risk factors for liver cancer in 504 patients with hepatitis B virus associated cirrhosis logistic regression analysis
Gang LI ; Hongliang SHANG ; Yuanyuan LIU ; Rui JIN ; Cheng WANG ; Yajuan XIE
Journal of Public Health and Preventive Medicine 2025;36(4):85-88
Objective Logistic regression model was used to analyze the risk factors of liver cancer in patients with hepatitis B virus-related cirrhosis. Methods A retrospective analysis was performed on 504 patients with hepatitis B cirrhosis who were treated in a hospital from April 2021 to April 2024. The occurrence of liver cancer was counted. The risk factors of liver cancer in patients with HBV-related cirrhosis were analyzed by logistic regression analysis. Results Among the 504 patients with hepatitis B cirrhosis, 101 patients developed liver cancer and 403 patients did not develop liver cancer, which were included in the liver cancer group (n=101) and the non-liver cancer group (n=403).. Among hepatitis B cirrhosis, the incidence rate of liver cancer was 20.04%. Compared with the non-liver cancer group, the proportion of patients with long-term drinking history, family history of liver cancer, history of diabetes mellitus, antiviral therapy, and HBV-DNA load>104 were higher in the liver cancer group (P<0.05). logistic regression analysis found that long-term drinking history (OR=3.077, 95%CI: 1.130-8.378, P=0.028), history of diabetes mellitus (OR=3.747, 95%CI: 1.765-7.954, P=0.001), no antiviral therapy (OR=3.466, 95%CI: 1.337-8.985, P=0.011) and HBV-DNA load>104 (OR=3.149, 95%CI: 1.353-7.328, P=0.008) could independently affect the occurrence of liver cancer in patients with hepatitis B cirrhosis. Conclusion According to logistic regression analysis, long-term drinking history, history of diabetes mellitus, no antiviral therapy, and HBV-DNA load>104 are risk factors for liver cancer in patients with HBV-related cirrhosis.
5.Relationship between type 2 diabetes mellitus and cognitive decline:a 4-year prospective cohort study
Liangjun DANG ; Yi ZHAO ; Ling GAO ; Shan WEI ; Chen CHEN ; Junlong FENG ; Jin WANG ; Kang HUO ; Qiumin QU ; Suhang SHANG
Journal of Xi'an Jiaotong University(Medical Sciences) 2025;46(5):749-754
Objective To investigate the relationship between type 2 diabetes mellitus(T2DM)and cognitive decline.Methods Data were obtained from the cognitive impairment cohort of middle-aged and elderly population in rural areas of Xi'an City.The cohort consisted of residents aged 40 years and older in two villages of Huyi District,Xi'an.The baseline survey was completed between October 2014 and March 2015,with two follow-up visits in 2016 and 2018.The present study was conducted on cognitively normal people at baseline.Individual characteristics,lifestyle,and medical history were collected;physical and biochemical examinations were completed.According to medical history of T2DM and fasting blood glucose,the study population was divided into non-T2DM group,pre-existing T2DM group,and new-onset T2DM group.The Mini-Mental State Examination(MMSE)was used to assess global cognitive function.Participants with a drop of≥2 points in MMSE score from baseline after 4 years were defined as having cognitive decline.Chi-square test and multivariate Logistic regression analysis were employed to analyze the effect of T2DM status on the risk of cognitive decline.Results A total of 1 350 subjects completed the follow-up.In the follow-up population,1 096(81.2%)were free of T2DM,158(11.7%)already had T2DM at baseline,and 96(7.1%)developed new-onset T2DM during the follow-up.Cognitive decline was observed in 230 individuals after 4 years,representing 17.0%of the study population.The new-onset T2DM group had the highest 4-year incidence of cognitive decline(non-T2DM group vs.pre-existing T2DM group vs.new-onset T2DM group:15.7%vs.20.9%vs.26.0%,P=0.014),and the incidence of cognitive decline in the newly-onset T2DM group was significantly higher than that in the non-T2DM group(P=0.009).Multivariate Logistic regression analysis showed that the new-onset T2DM group had an increased risk of cognitive decline compared with the non-T2DM group within 4 years(OR=1.726,95%CI:1.029-2.896,P=0.039).However,no significant difference in 4-year risk of cognitive decline in the pre-existing T2DM group was observed(OR=1.402,95%CI:0.890-2.210,P=0.145).Conclusion Through the 4-year follow-up study of cognitively normal adults aged 40 and above in rural Xi'an,it was found that new-onset T2DM patients face a significantly elevated risk of cognitive decline,suggesting that cognitive decline may occur in the early stage of T2DM.
6.Relationship between plasma amyloid β and cognitive impairment:a cross-sectional study based on a population in a rural area of Xi'an,China
Tongxin HU ; Huan MA ; Suhang SHANG ; Ling GAO ; Liangjun DANG ; Jingyi WANG ; Qiumin QU ; Jin WANG
Journal of Xi'an Jiaotong University(Medical Sciences) 2025;46(5):804-810
Objective To explore the relationship between plasma amyloid-β(Aβ)and cognitive impairment.Methods A total of all villagers(aged 40 years and above)from two villages of Xi'an,China,were enrolled.A validated Chinese version of the Mini-Mental State Examination and neuropsychological battery were used to assess cognition.Levels of fasting plasma Aβ1-42 and Aβ1-40 were tested using commercial enzyme-linked immunosorbent assay(ELISA).Relationship between plasma Aβ and cognitive impairment was analyzed using Logistic regression analysis.Results Of the 1 314 enrolled subjects,1 180(89.80%)had normal cognition,85(6.47%)had suspected cognitive impairment,and 49(3.73%)had probable cognitive impairment.Univariate analysis showed that plasma Aβ1-42/Aβ1-40 ratio was higher in the suspected cognitive impairment group than in the probable cognitive impairment group(P<0.05)and normal cognitive group(P<0.05);plasma Aβ1-42 level in the suspected cognitive impairment group was higher than that in normal cognitive group(P<0.05).The level of Aβ1-40 did not differ between the three groups.After correcting for confounding factors(including age,gender,degree of education,cognitive impairment risk factors,habits of living)in the multivariate Logistic regression analysis,the results were consistent with those in the univariate analysis.Conclusion Levels of plasma Aβ1-42 and Aβ1-42/Aβ1-40 ratio were elevated in patients with suspected cognitive impairment,indicating that elevated plasma Aβ1-42 and Aβ1-42/Aβ1-40 ratio may be more pronounced in early stage of cognitive impairment.They may be early biomarkers for cognitive impairment,which can help identify and intervene the disease earlier.
7.Relationships between plasma homocysteine levels and cognitive impairment:a cross-sectional study based on the rural population aged 40 years old and above in Xi'an,China
Yi ZHAO ; Chunyu LI ; Liangjun DANG ; Suhang SHANG ; Jingyi WANG ; Jin WANG ; Qiumin QU ; Wenhui LU
Journal of Xi'an Jiaotong University(Medical Sciences) 2025;46(5):755-762
Objective To investigate the relationship between plasma homocysteine(Hcy)levels and cognitive impairment(CI).Methods From November 2018 to January 2019,baseline data and cognitive function were collected from the participants aged≥40 years who lived in two villages in Huyi District,Xi'an,China.Their global cognitive function was assessed by Mini-Mental State Examination(MMSE)and the diagnosis of cognitive impairment was based on international guidelines.Fasting blood was collected in the morning,and plasma Hcy level was measured by the chemiluminometric assay.Multivariate Logistic regression analysis,subgroup analysis,and interaction analysis were performed to investigate the relationship between plasma Hcy and CI.Results A total of 1 805 subjects were included in the analysis.There were 1 056 females(58.5%),age ranged from 40 to 88 years[mean(58.99±9.52)years],and 145 participants(8.0%)were diagnosed as CI.The median plasma Hcy level in the overall population was 14.1(11.6,17.8)μmol/L.There were 729(40.4%)subjects in the HHcy group(>15.0 μmol/L)and 1 076(59.6%)in the normal group(≤15.0 μmol/L).Univariate analysis showed that the prevalence of CI was higher in the HHcy group than in the normal Hcy group(11.4%vs.5.8%,P<0.001).In multivariable Logistic regression fully adjusted for potential confounders,each 1 μmol/L increase in plasma Hcy level was associated with a 3.0%increased risk of CI(OR=1.030,95%CI:1.012-1.048,P=0.001).Interaction analysis indicated that sex,age,BMI,systolic blood pressure,history of stroke,and diabetes did not significantly modify this association.Conclusion Elevated plasma Hcy levels are associated with an increased risk of CI in people aged≥40 years.This indicates that HHcy may be a risk factor for CI.
8.Relationship between smoking and cognitive decline:a 4-year cohort prospective study on rural population in Xi'an
Jie LIU ; Zihan WANG ; Xiaojuan GUO ; Suhang SHANG ; Chen CHEN ; Jingyi WANG ; Qiumin QU ; Jin WANG
Journal of Xi'an Jiaotong University(Medical Sciences) 2025;46(5):769-774
Objective This study examined the association between smoking and cognitive decline through a cohort in rural population in Xi'an.Methods Data were collected from the cognitive impairment cohort of middle-aged and elderly people in rural areas of Xi'an.The cohort selected the population aged 40 years and above in rural Xi'an.The baseline survey was completed between October 2014 and March 2015,and two follow-up visits were conducted in 2016 and 2018.This study took the baseline cognitively normal population of this cohort as the research subjects.According to the survey results in 2018,the population was divided into three groups according to smoking status:smoking,quitting and non-smoking.Cognitive function was assessed by Mini-Mental State Examination(MMSE).△MMSE(2014 rating-2018 rating)≥2 was defined as cognitive decline,and △MMSE<2 was defined as cognitive stability.Binary Logistic regression model and stratified analysis were used to analyze the relationship between smoking and cognitive decline and the influence of age on the relationship.Results A total of 1 289 subjects were included in this study.According to smoking status in 2018,they were divided into non-smokers(910,70.6%),smokers(335,26.0%),and ex-smokers(44,3.4%).In the total population,there was no significant difference in the incidence of cognitive decline among non-smokers,smokers and ex-smokers(17.3%vs.16.1%vs.15.9%,P=0.880).When stratified by age,there was no significant difference in the incidence of cognitive decline among the three groups in the subgroup of age<65 years(16.5%vs.13.2%vs.12.1%,P=0.365).In the subgroup of age≥65 years,no significant difference was found in the incidence of cognitive decline among non-smokers,smokers and ex-smokers(20.8%vs.30.9%vs.27.3%,P=0.306).After adjusting for confounding factors,smokers had a significantly higher risk of cognitive decline than non-smokers(OR=14.139;95%CI:1.541-129.705;P=0.019).There was a trend of cognitive decline in the ex-smokers group,but with no statistical significance(OR=8.252;95%CI:0.630-108.175;P=0.108).Conclusion Smoking is positively associated with cognitive decline in the elderly,suggesting that smoking may accelerate cognitive decline in this population.
9.Relationship between carotid atherosclerosis and cognitive impairment:a cross-sectional study based on a population aged 40 years and older at high risk of stroke in a rural area of Xi'an City
Chen CHEN ; Ling GAO ; Suhang SHANG ; Liangjun DANG ; Shan WEI ; Jingyi WANG ; Jin WANG ; Qiumin QU ; Wenhui LU
Journal of Xi'an Jiaotong University(Medical Sciences) 2025;46(5):783-788
Objective To explore the relationship between carotid atherosclerosis(CAS)and cognitive impairment in the stroke high-risk population aged 40 years and above in the rural area of Xi'an City and determine whether CAS is a risk factor for cognitive impairment.Methods In this study,stroke high-risk population found in the Community and Rural Population Stroke High-risk Group Screening and Intervention Project carried out in Huyi District,Xi'an City,from October 2014 to March 2015 were selected as the research subjects.Color Doppler ultrasound was used to evaluate CAS,and CAS was defined as:carotid intima-media thickness(CIMT)≥1.0 mm,or carotid arteries(including common carotid artery,carotid sinus,internal carotid artery,and external carotid artery)have atherosclerotic plaques,or carotid stenosis.Mini-Mental State Examination(MMSE)was used to assess cognitive function.The MMSE score lower than the cut-off value(illiteracy ≤17,primary school ≤ 20 points,and junior high school and above education level ≤24 points)is defined as cognitive impairment.The study population was grouped according to the presence of CAS or cognitive impairment;univariate difference test and bivariate logistic regression were used to analyze the relationship between CAS and cognitive impairment.Results A total of 451 subjects were included in the analysis.The average age of the subjects was(58.7±9.83)years old,and 44.3%were female.Among them,329 cases(72.9%)had CAS and 57 cases(12.6%)met the diagnostic criteria for cognitive impairment.The prevalence of cognitive impairment in CAS group was significantly higher than that in non-CAS group(14.6%vs.7.4%,P=0.041).Multivariate logistic regression analysis showed that cognitive impairment was significantly correlated with age(OR=1.121,95%CI:1.056-1.189,P<0.001),but not with CAS(OR=1.008,95%CI:0.202-5.170,P=0.992).Conclusion No significant association between CAS and cognitive impairment was found in high stroke risk group aged 40 and above in rural areas of Xi'an.
10.Coronary heart disease combined with diabetes increases the risk of cognitive impairment:a cross-sectional study of the rural population in Xi'an
Meng WEI ; Yuxuan WENG ; Jie LIU ; Ling GAO ; Liangjun DANG ; Jin WANG ; Qiumin QU ; Suhang SHANG
Journal of Xi'an Jiaotong University(Medical Sciences) 2025;46(5):789-795
Objective To investigate the correlation between coronary heart disease(CHD)and cognitive impairment in rural populations aged 40 and above.Methods From October 2014 to March 2015,all residents aged 40 and above from two villages in Huyi District,Xi'an,were selected as study subjects.Information regarding their demographics,lifestyle habits,medical history,family history,physical examinations,and biochemical tests was collected.The participants were categorized into those with and without the history of CHD.Cognitive function was assessed using the Mini-Mental State Examination(MMSE),with scores below the cutoff(illiteracy≤17;primary school≤20;junior high school and above≤24)defined as cognitive impairment.Chi-square test was used to compare the prevalence of cognitive impairment between the CHD and non-CHD groups.Multivariate Logistic regression was employed to adjust for confounding factors in analyzing the relationship between CHD and cognitive impairment.Results A total of 1 833 subjects were included in the analysis,comprising 735 males(40.1%)and 57 individuals with CHD(3.1%).Among them,234 participants(13.3%)met the criteria for cognitive impairment.Univariate analysis showed a higher prevalence of cognitive impairment in the CHD group compared to the non-CHD group(24.6%vs.12.9%,P=0.016).Unadjusted binary Logistic regression analysis indicated a positive correlation between CHD and cognitive impairment(OR=2.199,95%CI:1.185-4.084,P=0.013).However,after adjusting for confounding factors such as gender,age,education level,hypertension,diabetes,dyslipidemia,stroke history and BMI,the association between CHD and cognitive impairment was not statistically significant(OR=1.265,95%CI:0.656-2.441,P=0.483).In the stratified analysis,among diabetic patients,CHD was significantly associated with a high risk of cognitive impairment(OR=4.191,95%CI:1.464-12.000,P=0.008).The prevalence of cognitive impairment significantly increased in patients with CHD combined with diabetes(OR=4.712,95%CI:1.651-13.449,P=0.004).Conclusion This study did not establish a direct association between CHD and cognitive impairment.However,this study suggests that the presence of CHD and diabetes mellitus is significantly associated with an increased risk of cognitive impairment.Future prospective studies with larger sample sizes should be conducted to further confirm the relationship between the two.


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