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.The Regulatory Mechanisms of Dopamine Homeostasis in Behavioral Functions Under Microgravity
Xin YANG ; Ke LI ; Ran LIU ; Xu-Dong ZHAO ; Hua-Lin WANG ; Lan-Qun MAO ; Li-Juan HOU
Progress in Biochemistry and Biophysics 2025;52(8):2087-2102
As China accelerates its efforts in deep space exploration and long-duration space missions, including the operationalization of the Tiangong Space Station and the development of manned lunar missions, safeguarding astronauts’ physiological and cognitive functions under extreme space conditions becomes a pressing scientific imperative. Among the multifactorial stressors of spaceflight, microgravity emerges as a particularly potent disruptor of neurobehavioral homeostasis. Dopamine (DA) plays a central role in regulating behavior under space microgravity by influencing reward processing, motivation, executive function and sensorimotor integration. Changes in gravity disrupt dopaminergic signaling at multiple levels, leading to impairments in motor coordination, cognitive flexibility, and emotional stability. Microgravity exposure induces a cascade of neurobiological changes that challenge dopaminergic stability at multiple levels: from the transcriptional regulation of DA synthesis enzymes and the excitability of DA neurons, to receptor distribution dynamics and the efficiency of downstream signaling pathways. These changes involve downregulation of tyrosine hydroxylase in the substantia nigra, reduced phosphorylation of DA receptors, and alterations in vesicular monoamine transporter expression, all of which compromise synaptic DA availability. Experimental findings from space analog studies and simulated microgravity models suggest that gravitational unloading alters striatal and mesocorticolimbic DA circuitry, resulting in diminished motor coordination, impaired vestibular compensation, and decreased cognitive flexibility. These alterations not only compromise astronauts’ operational performance but also elevate the risk of mood disturbances and motivational deficits during prolonged missions. The review systematically synthesizes current findings across multiple domains: molecular neurobiology, behavioral neuroscience, and gravitational physiology. It highlights that maintaining DA homeostasis is pivotal in preserving neuroplasticity, particularly within brain regions critical to adaptation, such as the basal ganglia, prefrontal cortex, and cerebellum. The paper also discusses the dual-edged nature of DA plasticity: while adaptive remodeling of synapses and receptor sensitivity can serve as compensatory mechanisms under stress, chronic dopaminergic imbalance may lead to maladaptive outcomes, such as cognitive rigidity and motor dysregulation. Furthermore, we propose a conceptual framework that integrates homeostatic neuroregulation with the demands of space environmental adaptation. By drawing from interdisciplinary research, the review underscores the potential of multiple intervention strategies including pharmacological treatment, nutritional support, neural stimulation techniques, and most importantly, structured physical exercise. Recent rodent studies demonstrate that treadmill exercise upregulates DA transporter expression in the dorsal striatum, enhances tyrosine hydroxylase activity, and increases DA release during cognitive tasks, indicating both protective and restorative effects on dopaminergic networks. Thus, exercise is highlighted as a key approach because of its sustained effects on DA production, receptor function, and brain plasticity, making it a strong candidate for developing effective measures to support astronauts in maintaining cognitive and emotional stability during space missions. In conclusion, the paper not only underscores the centrality of DA homeostasis in space neuroscience but also reflects the authors’ broader academic viewpoint: understanding the neurochemical substrates of behavior under microgravity is fundamental to both space health and terrestrial neuroscience. By bridging basic neurobiology with applied space medicine, this work contributes to the emerging field of gravitational neurobiology and provides a foundation for future research into individualized performance optimization in extreme environments.
3.Predicting Hepatocellular Carcinoma Using Brightness Change Curves Derived From Contrast-enhanced Ultrasound Images
Ying-Ying CHEN ; Shang-Lin JIANG ; Liang-Hui HUANG ; Ya-Guang ZENG ; Xue-Hua WANG ; Wei ZHENG
Progress in Biochemistry and Biophysics 2025;52(8):2163-2172
ObjectivePrimary liver cancer, predominantly hepatocellular carcinoma (HCC), is a significant global health issue, ranking as the sixth most diagnosed cancer and the third leading cause of cancer-related mortality. Accurate and early diagnosis of HCC is crucial for effective treatment, as HCC and non-HCC malignancies like intrahepatic cholangiocarcinoma (ICC) exhibit different prognoses and treatment responses. Traditional diagnostic methods, including liver biopsy and contrast-enhanced ultrasound (CEUS), face limitations in applicability and objectivity. The primary objective of this study was to develop an advanced, light-weighted classification network capable of distinguishing HCC from other non-HCC malignancies by leveraging the automatic analysis of brightness changes in CEUS images. The ultimate goal was to create a user-friendly and cost-efficient computer-aided diagnostic tool that could assist radiologists in making more accurate and efficient clinical decisions. MethodsThis retrospective study encompassed a total of 161 patients, comprising 131 diagnosed with HCC and 30 with non-HCC malignancies. To achieve accurate tumor detection, the YOLOX network was employed to identify the region of interest (ROI) on both B-mode ultrasound and CEUS images. A custom-developed algorithm was then utilized to extract brightness change curves from the tumor and adjacent liver parenchyma regions within the CEUS images. These curves provided critical data for the subsequent analysis and classification process. To analyze the extracted brightness change curves and classify the malignancies, we developed and compared several models. These included one-dimensional convolutional neural networks (1D-ResNet, 1D-ConvNeXt, and 1D-CNN), as well as traditional machine-learning methods such as support vector machine (SVM), ensemble learning (EL), k-nearest neighbor (KNN), and decision tree (DT). The diagnostic performance of each method in distinguishing HCC from non-HCC malignancies was rigorously evaluated using four key metrics: area under the receiver operating characteristic (AUC), accuracy (ACC), sensitivity (SE), and specificity (SP). ResultsThe evaluation of the machine-learning methods revealed AUC values of 0.70 for SVM, 0.56 for ensemble learning, 0.63 for KNN, and 0.72 for the decision tree. These results indicated moderate to fair performance in classifying the malignancies based on the brightness change curves. In contrast, the deep learning models demonstrated significantly higher AUCs, with 1D-ResNet achieving an AUC of 0.72, 1D-ConvNeXt reaching 0.82, and 1D-CNN obtaining the highest AUC of 0.84. Moreover, under the five-fold cross-validation scheme, the 1D-CNN model outperformed other models in both accuracy and specificity. Specifically, it achieved accuracy improvements of 3.8% to 10.0% and specificity enhancements of 6.6% to 43.3% over competing approaches. The superior performance of the 1D-CNN model highlighted its potential as a powerful tool for accurate classification. ConclusionThe 1D-CNN model proved to be the most effective in differentiating HCC from non-HCC malignancies, surpassing both traditional machine-learning methods and other deep learning models. This study successfully developed a user-friendly and cost-efficient computer-aided diagnostic solution that would significantly enhances radiologists’ diagnostic capabilities. By improving the accuracy and efficiency of clinical decision-making, this tool has the potential to positively impact patient care and outcomes. Future work may focus on further refining the model and exploring its integration with multimodal ultrasound data to maximize its accuracy and applicability.
4.Oncology-related emergencies discharged from the emergency department.
Si-Hua Yvonne GOH ; Juin Jie NG ; Shi-En Joanna CHAN ; Wei-Lin Tallie CHUA ; Venkataraman ANANTHARAMAN
Singapore medical journal 2025;66(2):97-101
INTRODUCTION:
Cancer patients attending emergency departments (EDs) often present with acute symptoms and are frequently admitted. This study aimed to characterise the profile of oncology patients who were discharged from the ED.
METHODS:
This was a retrospective audit of patients with cancer-related diagnoses who presented to the ED at the Singapore General Hospital (SGH) over a 6-month period from 1 October 2018 to 31 March 2019 and were directly discharged from the ED. Data was extracted from the hospital's electronic medical record system.
RESULTS:
Of the 492 participants included in the study, the majority were triaged as Priority 2 (61.4%), while 30.7% were triaged as Priority 3, 6.9% as Priority 1 and 1.0% as Priority 4. There was no statistical difference between the National Early Warning scores across the different triage categories in these patients. The most common complaint was (44.3%), followed by genitourinary symptoms (19.5%) and those related to devices, catheters or stomas (17.3%). More investigations of all types were done for patients being managed in Priority 1 (57.6%) than in the other triage categories (40.1% for Priority 2, 23.2% for Priority 3 and 12.0% for Priority 4). Treatment procedures carried out were mainly symptomatic (analgesics, antiemetics, proton pump inhibitors) for 79.8% of the patients. There were no significant differences in the proportion of patients requiring various treatment modalities among the triage categories.
CONCLUSION
Selected oncological patients may potentially be managed in an ambulatory setting.
Humans
;
Emergency Service, Hospital/statistics & numerical data*
;
Retrospective Studies
;
Female
;
Neoplasms/diagnosis*
;
Male
;
Singapore
;
Patient Discharge/statistics & numerical data*
;
Middle Aged
;
Aged
;
Triage
;
Adult
;
Emergencies
;
Aged, 80 and over
5.The impact of Anchor, a home visitation programme for maltreated children, on child developmental and behavioural outcomes.
Shi Hua CHAN ; Jean Yin OH ; Li Ming ONG ; Wen Hann CHOW ; Oh Moh CHAY ; Salam SOLIMAN ; Lourdes Mary DANIEL ; Pratibha AGARWAL ; Charmain Samantha TAN ; Jun Lin SAI ; Joanne Ferriol ESPECKERMAN ; Rehena SULTANA ; Cong Jin Wilson LOW ; Sita Padmini YELESWARAPU
Annals of the Academy of Medicine, Singapore 2025;54(4):208-218
INTRODUCTION:
Adverse childhood experiences (ACEs) are associated with significant long-term impacts, yet few interventions specifically target ACE exposure, especially in Asian populations. Anchor, Singapore's first home visitation programme, addresses maltreat-ment among preschool children. This study evaluated Anchor's impact on children's developmental and behavioural outcomes.
METHOD:
We conducted a prospective evaluation of children under 4 years assessed for maltreatment from November 2019 to July 2023. Developmental and behavioural progress was measured every 6 months using the Ages and Stages Questionnaires (ASQ-3) and ASQ:Social-Emotional (ASQ:SE-2), and annually using the Child Behaviour Checklist (CBCL).
RESULTS:
The results of 125 children (mean age 20.0 months, 48% female) were analysed. The mean length of stay in programme was 21.2 (7.3) months. At baseline, 92 (73.6%) children were at risk of develop-mental delay and 25 (31.7%) children aged ≥18 months had behavioural concerns. The programme was associated with significant improvements in gross motor (P=0.002) and fine motor (P=0.001) domains of the ASQ-3 and internalising problem scale (P=0.001) of the CBCL.
CONCLUSION
Anchor effectively enhances develop-mental and behavioural outcomes for children exposed to maltreatment. Targeted early intervention through such programmes can mitigate adverse impacts, optimising developmental trajectories and potentially reducing the long-term clinical and economic burdens associated with ACEs.
Humans
;
Female
;
Male
;
Child Abuse/therapy*
;
Child, Preschool
;
Singapore
;
House Calls
;
Infant
;
Prospective Studies
;
Child Development
;
Developmental Disabilities/epidemiology*
;
Program Evaluation
;
Child Behavior Disorders
;
Child Behavior
7.Acupuncture regulates dynamic flux of Ca2+, Na+, and H2O2 in skeletal muscle injury induced by eccentric exercise in rats.
Xue-Lin ZHANG ; Qian ZHAO ; Ai-Shan LIU ; Ming-Liang DUAN ; Jing-Jing DING ; Hua WANG
Acta Physiologica Sinica 2025;77(1):47-61
This study aimed to investigate the effects of acupuncture on dynamic changes in Ca2+, Na+, and H2O2 flux following eccentric exercise-induced muscle injury. The total of 324 healthy male Wistar rats were randomly divided into 6 groups: control group (C), eccentric exercise group (E), eccentric exercise with acupuncture group (EA), EA with TRP channel blocker group (EAT), EA with NOX2 blocker group (EAN) and EA with placebo group (EAP). Gastrocnemius muscles were subject to lengthening contractions with percutaneous electrical stimulation, followed by immediate pretreatment with blocking agents. After 30 min, acupuncture needling was administered to the gastrocnemius muscle, and real-time dynamic changes of Ca2+, Na+ and H2O2 flux were measured with non-invasive micro-test technique during the needle retention period, immediately, 3 h, 6 h, and 24 h post-extraction respectively. Results showed that compared with the E group, acupuncture significantly increased net Ca2+ efflux (P < 0.05), extended the period of net Na+ influx, and significantly decreased net H2O2 efflux (P < 0.05). However, these effects were significantly attenuated in the EAT and EAN groups, where excessive net H2O2 efflux was observed (P < 0.001). These findings indicate that acupuncture regulates the dynamic changes of Ca2+, Na+ and H2O2 flux by activating the TRP channels and interacting with NOX2 activity following eccentric exercise-induced skeletal muscle injury.
Animals
;
Muscle, Skeletal/metabolism*
;
Rats, Wistar
;
Rats
;
Male
;
Calcium/metabolism*
;
Hydrogen Peroxide/metabolism*
;
Physical Conditioning, Animal
;
Sodium/metabolism*
;
Acupuncture Therapy
;
NADPH Oxidase 2
8.The regulatory effect and mechanism of PGC-1α on mitochondrial function.
Song-Hua NAN ; Chao-Jie PENG ; Ying-Lin CUI
Acta Physiologica Sinica 2025;77(2):300-308
Peroxisome proliferator-activated receptor γ coactivator 1 α (PGC-1α) is a core member of the PGC-1 family and serves as a transcriptional coactivator, playing a crucial regulatory role in various diseases. Mitochondria, the main site of cellular energy metabolism, are essential for maintaining cell growth and function. Their function is regulated by various transcription factors and coactivators. PGC-1α regulates the biogenesis, dynamics, energy metabolism, calcium homeostasis, and autophagy processes of mitochondria by interacting with multiple nuclear transcription factors, thereby exerting significant effects on mitochondrial function. This review explores the biological functions of PGC-1α and its regulatory effects and related mechanisms on mitochondria, providing important information for our in-depth understanding of the role of PGC-1α in cellular metabolism. The potential role of PGC-1α in metabolic diseases, cardiovascular diseases, and neurodegenerative diseases was also discussed, providing a theoretical basis for the development of new treatment strategies.
Humans
;
Mitochondria/metabolism*
;
Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/physiology*
;
Animals
;
Energy Metabolism/physiology*
;
Neurodegenerative Diseases/physiopathology*
;
Autophagy/physiology*
;
Transcription Factors/physiology*
;
Metabolic Diseases/physiopathology*
;
Cardiovascular Diseases/physiopathology*
9.Material basis of toad oil and its pharmacodynamic effect in a mouse model of atopic dermatitis.
Yu-Yang LIU ; Xin-Wei YAN ; Bao-Lin BIAN ; Yao-Hua DING ; Xiao-Lu WEI ; Meng-Yao TIAN ; Wei WANG ; Hai-Yu ZHAO ; Yan-Yan ZHOU ; Hong-Jie WANG ; Ying YANG ; Nan SI
China Journal of Chinese Materia Medica 2025;50(1):165-177
This study aims to comprehensively analyze the material basis of toad visceral oil(hereafter referred to as toad oil), and explore the pharmacological effect of toad oil on atopic dermatitis(AD). Ultra-high performance liquid chromatography-linear ion trap/orbitrap high-resolution mass spectrometry(UHPLC-LTQ-Orbitrap-MS) and gas chromatography-mass spectrometry(GC-MS) were employed to comprehensively identify the chemical components in toad oil. The animal model of AD was prepared by the hapten stimulation method. The modeled animals were respectively administrated with positive drug(0.1% hydrocortisone butyrate cream) and low-and high-doses(1%, 10%) of toad oil by gavage. The effect of toad oil on AD was evaluated with the AD score, ear swelling rate, spleen index, and pathological section results as indicators. A total of 99 components were identified by UHPLC-LTQ-Orbitrap-MS, including 14 bufadienolides, 7 fatty acids, 6 alkaloids, 10 ketones, 18 amides, and other compounds. After methylation of toad oil samples, a total of 20 compounds were identified by GC-MS. Compared with the model group, the low-and high-dose toad oil groups showed declined AD score, ear swelling rate, and spleen index, alleviated skin lesions, and reduced infiltrating mast cells. This study comprehensively analyzes the chemical composition and clarifies the material basis of toad oil. Meanwhile, this study proves that toad oil has a good therapeutic effect on AD and is a reserve resource of traditional Chinese medicine for external use in the treatment of AD.
Animals
;
Dermatitis, Atopic/immunology*
;
Disease Models, Animal
;
Mice
;
Male
;
Gas Chromatography-Mass Spectrometry
;
Humans
;
Bufonidae
;
Oils/administration & dosage*
;
Chromatography, High Pressure Liquid
;
Female
;
Mice, Inbred BALB C
10.Advances in role and mechanism of traditional Chinese medicine active ingredients in regulating balance of Th1/Th2 and Th17/Treg immune responses in asthma patients.
Ya-Sheng DENG ; Lan-Hua XI ; Yan-Ping FAN ; Wen-Yue LI ; Yong-Hui LIU ; Zhao-Bing NI ; Ming-Chan WEI ; Jiang LIN
China Journal of Chinese Materia Medica 2025;50(4):1000-1021
Asthma is a chronic inflammatory disease involving multiple inflammatory cells and cytokines. Its pathogenesis is complex, involving various cells and cytokines. Traditional Chinese medicine(TCM) theory suggests that the pathogenesis of asthma is closely related to the dysfunction of internal organs such as the lungs, spleen, and kidneys. In contrast, modern immunological studies have revealed the central role of T helper 1(Th1)/T helper 2(Th2) and T helper 17(Th17)/regulatory T(Treg) cellular immune imbalance in the pathogenesis of asthma. Th1/Th2 imbalance is manifested as hyperfunction of Th2 cells, which promotes the synthesis of immunoglobulin E(IgE) and the activation of eosinophil granulocytes, leading to airway hyperresponsiveness and inflammation.Meanwhile, Th17/Treg imbalance exacerbates the inflammatory response in the airways, further contributing to asthma pathology.Currently, therapeutic strategies for asthma are actively exploring potential targets for regulating the balance of Th1/Th2 and Th17/Treg immune responses. These targets include cytokines, transcription factors, key proteins, and non-coding RNAs. Precisely regulating the expression and function of these targets can effectively modulate the activation and differentiation of immune cells. In recent years,traditional Chinese medicine active ingredients have shown unique potential and prospects in the field of asthma treatment. Based on this, the present study systematically summarizes the efficacy and specific mechanisms of TCM active ingredients in treating asthma by regulating Th1/Th2 and Th17/Treg immune balance through literature review and analysis. These active ingredients, including flavonoids, terpenoids, polysaccharides, alkaloids, and phenolic acids, exert their effects through various mechanisms, such as inhibiting the activation of inflammatory cells, reducing the release of cytokines, and promoting the normal differentiation of immune cells. This study aims to provide a solid foundation for the widespread application and in-depth development of TCM in asthma treatment and to offer new ideas for clinical research and drug development of asthma.
Asthma/genetics*
;
Humans
;
Drugs, Chinese Herbal/chemistry*
;
Th2 Cells/drug effects*
;
Th17 Cells/drug effects*
;
T-Lymphocytes, Regulatory/drug effects*
;
Th1 Cells/drug effects*
;
Animals
;
Cytokines/immunology*
;
Medicine, Chinese Traditional

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