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 a deep learning-driven centerline extraction algorithm for optimizing the diagnosis of the"gray zone"in noninvasive coronary fractional flow reserve
Zi-qiang GUO ; Xi WANG ; Zi-nuan LIU ; Yi-pu DING ; Ran XIN ; Dong-kai SHAN ; Jun GUO ; Yun-dai CHEN ; Jun-jie YANG
Chinese Journal of Interventional Cardiology 2025;33(6):312-318
Objective To evaluate the diagnostic performance of the minimum-cost-path-based CT angiography-derived fractional flow reserve(MCP-FFR)and the deep learning-driven CT angiography-derived fractional flow reserve(DeepCL-FFR),and to particularly explore the potential value of the DeepCL algorithm in improving diagnostic accuracy within the"gray zone."Methods A retrospective analysis was conducted on 151 coronary vessels from 109 patients with coronary artery disease,who were hospitalized at the General Hospital of the People's Liberation Army between January 2020 and June 2021.Pearson correlation and Bland-Altman plots were employed to assess the correlation and agreement of the two CT-FFR methods with invasive FFR.A CT-FFR range of 0.70-0.80 was defined as the diagnostic"gray zone."The accuracy,sensitivity,specificity,positive predictive value,and negative predictive value for detecting hemodynamic abnormalities were calculated and analyzed.The DeLong test was used to compare the areas under the receiver operating characteristic curves(AUC)between the two CT-FFR calculation methods.Results Both CT-FFR methods exhibited a positive correlation with invasive FFR(MCP-FFR:r=0.75,P<0.001;DeepCL-FFR:r=0.86,P<0.001)and showed good agreement(MCP-FFR:mean difference=0.010,P=0.351;DeepCL-FFR:mean difference=-0.003,P=0.772).Both DeepCL-FFR(AUC 0.97,95%CI 0.94-0.99)and MCP-FFR(AUC 0.92,95%CI 0.88-0.97)demonstrated favorable diagnostic performance for detecting hemodynamic abnormalities(P=0.122).In the"gray zone"for hemodynamic abnormality,the diagnostic accuracy of MCP-FFR was 68.8%,whereas DeepCL-FFR increased it to 89.7%.DeepCL-FFR also exhibited superior diagnostic performance(AUC 0.89,95%CI 0.73-0.99)within the"gray zone,"which was significantly higher than that of MCP-FFR(AUC 0.71,95%CI 0.54-0.87)(P<0.001).Conclusions The deep learning-driven coronary centerline extraction algorithm,DeepCL,demonstrates superior diagnostic performance in CT-FFR for detecting hemodynamic abnormalities,particularly by significantly improving diagnostic accuracy in the"gray zone."
3.Isoliquiritigenin alleviates abnormal endoplasmic reticulum stress induced by type 2 diabetes mellitus
Kai-yi LAI ; Wen-wen DING ; Jia-yu ZHANG ; Xiao-xue YANG ; Wen-bo GAO ; Yao XIAO ; Ying LIU
Acta Pharmaceutica Sinica 2025;60(1):130-140
Isoliquiritigenin (ISL) is a chalcone compound isolated from licorice, known for its anti-diabetic, anti-cancer, and antioxidant properties. Our previous study has demonstrated that ISL effectively lowers blood glucose levels in type 2 diabetes mellitus (T2DM) mice and improves disturbances in glucolipid and energy metabolism induced by T2DM. This study aims to further investigate the effects of ISL on alleviating abnormal endoplasmic reticulum stress (ERS) caused by T2DM and to elucidate its molecular mechanisms.
4.Role of stem cells in scalp aging and related therapeutic strategies
Weiyun DING ; Jinran LIN ; Qingmei LIU ; Yue ZHANG ; Kai YANG ; Chunya NI ; Wenyu WU
Chinese Journal of Dermatology 2025;58(7):671-675
Changes in hair follicle stem cells (HFSCs) can affect scalp aging and hair growth. With increasing age, HFSCs exhibit a decrease in quiescence maintenance and self-renewal capacity, as well as differentiation potential, leading to shortened hair growth cycles and even hair loss. This review summarizes recent research advances in the multifactorial interactions underlying hair loss, including the regulatory mechanisms of HFSC quiescence, the impact of aging on HFSC function, and aging of the stem cell microenvironment. Additionally, this review discusses the relationship between stem cells and hair shafts, and the mechanisms of action of stem cells in scalp aging, including alterations in signaling pathways, chromatin remodeling, and epigenetic regulation, etc. Furthermore, stem cell-based therapeutic strategies are summarized, such as the use of stem cells or their secreting exosomes, modulation of the stem cell microenvironment, and pharmacological interventions.
5.A test-negative study on the protective effectiveness of acellular pertussis vaccine in children aged 2 months to 6 years based on propensity score matching method
Yao ZHU ; Yang ZHOU ; Xiaohua QI ; Xuejiao PAN ; Linling DING ; Fuxing CHEN ; Kai GAO ; Yu HU ; Hanqing HE
Chinese Journal of Preventive Medicine 2025;59(11):1834-1839
Objective:To evaluate the protective effectiveness (VE) of the acellular pertussis vaccine (aPV) against pertussis in children aged 2 months to 6 years.Methods:A test-negative case-control study was conducted among children aged 2 months to 6 years who sought medical care for cough and underwent pertussis nucleic acid testing at sentinel surveillance hospitals in Zhejiang Province in 2024. Cases were defined as those with positive pertussis nucleic acid test results, while controls were test-negative individuals matched 1∶1 based on propensity scores using the caliper matching method. Conditional logistic regression models were used to calculate odds ratios ( ORs) and VEs. Results:Among the 658 participants, 31.76% (209 cases) tested positive for pertussis. After propensity score matching, 203 cases and 203 controls were included in the analysis. The VE of 1-2, 3, and 4 doses of aPV against pertussis was 52.46% (95% CI:-39.82%-83.84%), 65.22% (95% CI: 6.86%-87.02%), and 72.21% (95% CI: 34.33%-88.24%), respectively. For pertussis-related hospitalization, the VE of 1-3 and 4 doses was 80.95% (95% CI:31.38%-94.71%) and 86.79% (95% CI: 51.89%-96.37%). The VE for those who completed 4 doses of vaccination and had intervals of less than 2 years, 2 years, 3 years, and 4 years or more after vaccination were 91.15% (95% CI: 67.61%-97.58%), 84.70% (95% CI: 43.71%-95.84%),56.23% (95% CI:-47.58%-87.02%), and 49.92% (95% CI:-83.74%-86.35%), respectively. Conclusion:The VE of aPV against pertussis in children aged 2 months to 6 years increases with the number of doses administered, and it is more effective in preventing hospitalization due to pertussis. The VE declines rapidly over time after the last dose. It is recommended to follow the new pertussis immunization program for timely and full vaccination.
6.The Histone Methyltransferase EZH2 is Downregulated in the Terminal Differentiation of Cardiomyocytes
Wan-Yi ZHANG ; Wan-Lei ZHANG ; Yuan-Yuan LIU ; Ling-Er DING ; Qi-Kai TANG ; Zhen-Hang LI ; Hao-Ying YANG ; Tao LI
Chinese Journal of Biochemistry and Molecular Biology 2025;41(3):415-425
Enhancer of zeste homolog 2(EZH2)is a histone methyltransferase It mediates trimethylation of lysine 27 on histone H3,thereby facilitating the epigenetic silencing of downstream genes.In conjunc-tion with SUZ12,EED,and other components,it constitutes the polycomb repressive complex 2(PRC2)complex.While EZH2 is intricately involved in cellular proliferation and cardiac development,the chan-ges in its expression during cardiac terminal differentiation remain elusive.In this study,we employed differential gene expression analysis of embryonic and adult myocardial cells using the GEO database,and found that EZH2 is highly expressed in embryonic myocardium,but is present at very low levels in adult myocardium(P<0.0001).Conversely,the expression changes of PRC2 members SUZ12 and EED are not as pronounced.Online analysis through the Tabula Muris database indicates that under physiological conditions,various cell subpopulations in the adult mouse heart exhibit negligible expression of EZH2.Immunohistochemical staining of mouse cardiac tissues shows that EZH2 is highly expressed in embryonic and neonatal myocardium but declines progressively from the first day after birth(P<0.0001),becoming almost undetectable by the third day.Western blotting further confirms the rapid disappearance of EZH2 expression post-birth(P<0.05),with EZH1 compensating for the downregulation of EZH2 to maintain H3K27me3 modification levels.Additionally,using the P19 teratocarcinoma stem cell model for cardio-myocyte differentiation,it is observed that EZH2 is significantly upregulated during the transition from cardiac progenitor cells to spontaneously beating cardiomyocytes,correlating with the expression of the cardiomyocyte transcription factor Gata4(P<0.01).Targeted degradation of EZH2 using the small mole-cule drug MS1943 significantly inhibits the proliferation of induced cardiomyocytes,as evidenced by 5-e-thynyl-2'-deoxyuridine(EdU)incorporation assays(P<0.01),and RT-qPCR reveals a marked in-crease in the expression of the proliferation inhibitor CDKN1A(P<0.01).In summary,the high expres-sion of EZH2 in embryonic myocardial cells is associated with enhanced cell proliferation.The rapid loss of EZH2 expression postnatally correlates with the loss of proliferative capacity in cardiomyocytes,mark-ing it as a key indicator of cardiac terminal differentiation.
7.Evaluation of a deep learning-driven centerline extraction algorithm for optimizing the diagnosis of the"gray zone"in noninvasive coronary fractional flow reserve
Zi-qiang GUO ; Xi WANG ; Zi-nuan LIU ; Yi-pu DING ; Ran XIN ; Dong-kai SHAN ; Jun GUO ; Yun-dai CHEN ; Jun-jie YANG
Chinese Journal of Interventional Cardiology 2025;33(6):312-318
Objective To evaluate the diagnostic performance of the minimum-cost-path-based CT angiography-derived fractional flow reserve(MCP-FFR)and the deep learning-driven CT angiography-derived fractional flow reserve(DeepCL-FFR),and to particularly explore the potential value of the DeepCL algorithm in improving diagnostic accuracy within the"gray zone."Methods A retrospective analysis was conducted on 151 coronary vessels from 109 patients with coronary artery disease,who were hospitalized at the General Hospital of the People's Liberation Army between January 2020 and June 2021.Pearson correlation and Bland-Altman plots were employed to assess the correlation and agreement of the two CT-FFR methods with invasive FFR.A CT-FFR range of 0.70-0.80 was defined as the diagnostic"gray zone."The accuracy,sensitivity,specificity,positive predictive value,and negative predictive value for detecting hemodynamic abnormalities were calculated and analyzed.The DeLong test was used to compare the areas under the receiver operating characteristic curves(AUC)between the two CT-FFR calculation methods.Results Both CT-FFR methods exhibited a positive correlation with invasive FFR(MCP-FFR:r=0.75,P<0.001;DeepCL-FFR:r=0.86,P<0.001)and showed good agreement(MCP-FFR:mean difference=0.010,P=0.351;DeepCL-FFR:mean difference=-0.003,P=0.772).Both DeepCL-FFR(AUC 0.97,95%CI 0.94-0.99)and MCP-FFR(AUC 0.92,95%CI 0.88-0.97)demonstrated favorable diagnostic performance for detecting hemodynamic abnormalities(P=0.122).In the"gray zone"for hemodynamic abnormality,the diagnostic accuracy of MCP-FFR was 68.8%,whereas DeepCL-FFR increased it to 89.7%.DeepCL-FFR also exhibited superior diagnostic performance(AUC 0.89,95%CI 0.73-0.99)within the"gray zone,"which was significantly higher than that of MCP-FFR(AUC 0.71,95%CI 0.54-0.87)(P<0.001).Conclusions The deep learning-driven coronary centerline extraction algorithm,DeepCL,demonstrates superior diagnostic performance in CT-FFR for detecting hemodynamic abnormalities,particularly by significantly improving diagnostic accuracy in the"gray zone."
8.Role of stem cells in scalp aging and related therapeutic strategies
Weiyun DING ; Jinran LIN ; Qingmei LIU ; Yue ZHANG ; Kai YANG ; Chunya NI ; Wenyu WU
Chinese Journal of Dermatology 2025;58(7):671-675
Changes in hair follicle stem cells (HFSCs) can affect scalp aging and hair growth. With increasing age, HFSCs exhibit a decrease in quiescence maintenance and self-renewal capacity, as well as differentiation potential, leading to shortened hair growth cycles and even hair loss. This review summarizes recent research advances in the multifactorial interactions underlying hair loss, including the regulatory mechanisms of HFSC quiescence, the impact of aging on HFSC function, and aging of the stem cell microenvironment. Additionally, this review discusses the relationship between stem cells and hair shafts, and the mechanisms of action of stem cells in scalp aging, including alterations in signaling pathways, chromatin remodeling, and epigenetic regulation, etc. Furthermore, stem cell-based therapeutic strategies are summarized, such as the use of stem cells or their secreting exosomes, modulation of the stem cell microenvironment, and pharmacological interventions.
9.The Histone Methyltransferase EZH2 is Downregulated in the Terminal Differentiation of Cardiomyocytes
Wan-Yi ZHANG ; Wan-Lei ZHANG ; Yuan-Yuan LIU ; Ling-Er DING ; Qi-Kai TANG ; Zhen-Hang LI ; Hao-Ying YANG ; Tao LI
Chinese Journal of Biochemistry and Molecular Biology 2025;41(3):415-425
Enhancer of zeste homolog 2(EZH2)is a histone methyltransferase It mediates trimethylation of lysine 27 on histone H3,thereby facilitating the epigenetic silencing of downstream genes.In conjunc-tion with SUZ12,EED,and other components,it constitutes the polycomb repressive complex 2(PRC2)complex.While EZH2 is intricately involved in cellular proliferation and cardiac development,the chan-ges in its expression during cardiac terminal differentiation remain elusive.In this study,we employed differential gene expression analysis of embryonic and adult myocardial cells using the GEO database,and found that EZH2 is highly expressed in embryonic myocardium,but is present at very low levels in adult myocardium(P<0.0001).Conversely,the expression changes of PRC2 members SUZ12 and EED are not as pronounced.Online analysis through the Tabula Muris database indicates that under physiological conditions,various cell subpopulations in the adult mouse heart exhibit negligible expression of EZH2.Immunohistochemical staining of mouse cardiac tissues shows that EZH2 is highly expressed in embryonic and neonatal myocardium but declines progressively from the first day after birth(P<0.0001),becoming almost undetectable by the third day.Western blotting further confirms the rapid disappearance of EZH2 expression post-birth(P<0.05),with EZH1 compensating for the downregulation of EZH2 to maintain H3K27me3 modification levels.Additionally,using the P19 teratocarcinoma stem cell model for cardio-myocyte differentiation,it is observed that EZH2 is significantly upregulated during the transition from cardiac progenitor cells to spontaneously beating cardiomyocytes,correlating with the expression of the cardiomyocyte transcription factor Gata4(P<0.01).Targeted degradation of EZH2 using the small mole-cule drug MS1943 significantly inhibits the proliferation of induced cardiomyocytes,as evidenced by 5-e-thynyl-2'-deoxyuridine(EdU)incorporation assays(P<0.01),and RT-qPCR reveals a marked in-crease in the expression of the proliferation inhibitor CDKN1A(P<0.01).In summary,the high expres-sion of EZH2 in embryonic myocardial cells is associated with enhanced cell proliferation.The rapid loss of EZH2 expression postnatally correlates with the loss of proliferative capacity in cardiomyocytes,mark-ing it as a key indicator of cardiac terminal differentiation.
10.A test-negative study on the protective effectiveness of acellular pertussis vaccine in children aged 2 months to 6 years based on propensity score matching method
Yao ZHU ; Yang ZHOU ; Xiaohua QI ; Xuejiao PAN ; Linling DING ; Fuxing CHEN ; Kai GAO ; Yu HU ; Hanqing HE
Chinese Journal of Preventive Medicine 2025;59(11):1834-1839
Objective:To evaluate the protective effectiveness (VE) of the acellular pertussis vaccine (aPV) against pertussis in children aged 2 months to 6 years.Methods:A test-negative case-control study was conducted among children aged 2 months to 6 years who sought medical care for cough and underwent pertussis nucleic acid testing at sentinel surveillance hospitals in Zhejiang Province in 2024. Cases were defined as those with positive pertussis nucleic acid test results, while controls were test-negative individuals matched 1∶1 based on propensity scores using the caliper matching method. Conditional logistic regression models were used to calculate odds ratios ( ORs) and VEs. Results:Among the 658 participants, 31.76% (209 cases) tested positive for pertussis. After propensity score matching, 203 cases and 203 controls were included in the analysis. The VE of 1-2, 3, and 4 doses of aPV against pertussis was 52.46% (95% CI:-39.82%-83.84%), 65.22% (95% CI: 6.86%-87.02%), and 72.21% (95% CI: 34.33%-88.24%), respectively. For pertussis-related hospitalization, the VE of 1-3 and 4 doses was 80.95% (95% CI:31.38%-94.71%) and 86.79% (95% CI: 51.89%-96.37%). The VE for those who completed 4 doses of vaccination and had intervals of less than 2 years, 2 years, 3 years, and 4 years or more after vaccination were 91.15% (95% CI: 67.61%-97.58%), 84.70% (95% CI: 43.71%-95.84%),56.23% (95% CI:-47.58%-87.02%), and 49.92% (95% CI:-83.74%-86.35%), respectively. Conclusion:The VE of aPV against pertussis in children aged 2 months to 6 years increases with the number of doses administered, and it is more effective in preventing hospitalization due to pertussis. The VE declines rapidly over time after the last dose. It is recommended to follow the new pertussis immunization program for timely and full vaccination.

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