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.

Objective: This study characterizes the demographic and clinical profiles of patients undergoing unilateral biportal endoscopic spine surgery (UBE ESS) for lumbar decompression/discectomy at a tertiary hospital in Singapore. It examines service implementation across multiple senior surgeons, evaluates preliminary clinical outcomes, and describes the learning curve observed during early adoption among surgeons already experienced in minimally invasive spine surgery, benchmarked against international standards. In the context of increasing global uptake of endoscopic techniques, this work provides evidence to inform institutional adoption and surgeon training. This analysis forms part of a multi-paper series comparing surgeon experience and patient outcomes between conventional minimally invasive approaches and UBE ESS for lumbar decompression/discectomy. Methods: We conducted a retrospective review of 111 patients who underwent UBE lumbar decompression/discectomy at a public tertiary hospital between October 2022 and April 2024. Data on patient demographics, comorbidities, presenting symptoms, operative details, and clinical outcomes, including visual analogue scale (VAS) scores and 36-Item Short Form Health Survey (SF-36) health domains, were analyzed using appropriate statistical methods. Results: The mean patient age was 56.8 years, with a slight female predominance (54.1%). Statistically significant improvements were observed in VAS scores for both back and leg pain (p<0.05), alongside significant gains in SF-36 domains including physical functioning, bodily pain, vitality, and social functioning. Operative times decreased progressively with increasing case volume, consistent with the presence of a procedural learning curve. Conclusion UBE ESS for lumbar decompression/discectomy is a safe and efficacious technique that can be successfully adopted by spinal surgeons with prior minimally invasive surgical experience. Operative time demonstrates a meaningful reduction once the initial learning curve has been overcome. ESS provides a reproducible option for the treatment of degenerative lumbar spine disease in the tertiary hospital setting in Singapore, with outcomes comparable to established international benchmarks. Future work will include long-term follow-up of this patient cohort and direct comparison with conventional minimally invasive techniques in subsequent studies.

Objective: Spinal stenosis and degenerative spinal disorders are increasingly prevalent and have a substantial impact on quality of life. Surgical decompression, performed using either open microscopic or endoscopic approaches, remains a cornerstone of management for these conditions. This study examines evolving trends in single-level lumbar spinal decompression procedures performed at a tertiary academic hospital in Singapore. Methods: A retrospective observational study was conducted involving 588 patients who underwent single-level spinal decompression between 2021 and 2024, including endoscopic spine surgery (ESS; n=364) and microdecompression (n=224). Primary outcome measures were changes in 36-Item Short Form Health Survey (SF-36) and visual analogue scale (VAS) scores at 3 months, 6 months, and 2 years postoperatively. Secondary outcomes included length of hospital stay, reoperation rates, and operative time. Patient demographics, spinal level and pathology characteristics, surgical techniques, and postoperative outcomes were analyzed. Difference-in-differences (DID) analysis was used to compare outcomes between the 2 groups. Results: Both groups demonstrated significant postoperative improvements in SF-36 and VAS scores. At 2 years, Short Form Health Survey physical function (SFPF) scores improved in the endoscopic group (mean difference [MD], 18.6; standard deviation [SD], 21.7; p=0.064) and in the open microscopic group (MD, 36.7; SD, 20.9; p=0.007), with a non-significant DID of -18.1 (p=0.155). No DID comparisons across SF-36 domains reached statistical significance. Mean operative time for endoscopic procedures decreased from 249 minutes in 2022 to 145 minutes in 2024, reflecting a procedural learning curve. Surgeons with higher endoscopic caseloads exhibited greater improvements in functional outcomes. Conclusion Both endoscopic and open microscopic decompression achieve comparable short- and long-term clinical outcomes. ESS provides similar effectiveness while being associated with shorter recovery periods and reduced hospital stay. Further research is warranted to identify factors contributing to incomplete symptom resolution or the need for revision surgery.

OBJECTIVES: We propose a myocardial infarction (MI) detection and localization model for improving the diagnostic accuracy for MI to provide assistance to clinical decision-making. METHODS: The proposed model was constructed based on multi-scale field residual blocks fusion modified channel attention (MSF-RB-MCA). The model utilizes lead II electrocardiogram (ECG) signals to detect and localize MI, and extracts different levels of feature information through the multi-scale field residual block. A modified channel attention for automatic adjustment of the feature weights was introduced to enhance the model's ability to focus on the MI region, thereby improving the accuracy of MI detection and localization. RESULTS: A 5-fold cross-validation test of the model was performed using the publicly available Physikalisch-Technische Bundesanstalt (PTB) dataset. For MI detection, the model achieved an accuracy of 99.96% on the test set with a specificity of 99.84% and a sensitivity of 99.99%. For MI localization, the accuracy, specificity and sensitivity were 99.81%, 99.98% and 99.65%, respectively. The performances of the model for MI detection and localization were superior to those of other comparison models. CONCLUSIONS The proposed MSF-RB-MCA model shows excellent performance in AI detection and localization based on lead II ECG signals, demonstrating its great potential for application in wearable devices.
Myocardial Infarction/diagnosis* ; Humans ; Electrocardiography/methods* ; Signal Processing, Computer-Assisted ; Algorithms ; Sensitivity and Specificity

INTRODUCTION: The primary objective of this guideline is to establish evidence-based recommendations for the clinical use of parenteral nutrition (PN) in adult patients within the acute hospital setting in Singapore. METHOD: An expert workgroup, consisting of healthcare practitioners actively involved in clinical nutrition support across all public health institutions, systematically evaluated existing evidence and addressed clinical questions relating to PN therapy. RESULTS: This clinical practice guideline developed 30 recommendations for PN therapy, which cover these key aspects related to PN use: indications, patient assess-ment, titration and formulation of PN bags, access routes and devices, and monitoring and management of PN-related complications. CONCLUSION This guideline provides recommendations to ensure appropriate and safe clinical practice of PN therapy in adult patients within the acute hospital setting.
Humans ; Singapore ; Parenteral Nutrition/adverse effects* ; Adult

In this paper, near-infrared spectroscopy(NIRS) was employed to analyze 129 batches of commercial products of Reduning Injection. The batch reporting rate was estimated according to the report of Reduning Injection in the direct adverse drug reaction(ADR) reporting system of the drug marketing authorization holder of the Center for Drug Reevaluation of the National Medical Products Administration(National Center for ADR Monitoring) from August 2021 to August 2022. According to the batch reporting rate, the samples of Reduning Injection were classified into those with potential risks and those being safe. No processing, random oversampling(ROS), random undersampling(RUS), and synthetic minority over-sampling technique(SMOTE) were then employed to balance the unbalanced data. After the samples were classified according to appropriate sampling methods, competitive adaptive reweighted sampling(CARS), successive projections algorithm(SPA), uninformative variables elimination(UVE), and genetic algorithm(GA) were respectively adopted to screen the features of spectral data. Then, support vector machine(SVM), logistic regression(LR), k-nearest neighbors(KNN), naive bayes(NB), random forest(RF), and artificial neural network(ANN) were adopted to establish the risk prediction models. The effects of the four feature extraction methods on the accuracy of the models were compared. The optimal method was selected, and bayesian optimization was performned to optimize the model parameters to improve the accuracy and robustness of model prediction. To explore the correlations between potential risks of clinical use and quality test data, TreeNet was employed to identify potential quality parameters affecting the clinical safety of Reduning Injection. The results showed that the models established with the SVM, LR, KNN, NB, RF, and ANN algorithms had the F1 scores of 0.85, 0.85, 0.86, 0.80, 0.88, and 0.85 and the accuracy of 88%, 88%, 88%, 85%, 91%, and 88%, respectively, and the prediction time was less than 5 s. The results indicated that the established models were accurate and efficient. Therefore, near infrared spectroscopy combined with machine learning algorithms can quickly predict the potential risks of clinical use of Reduning Injection in batches. Three key quality parameters that may affect clinical safety were identified by TreeNet, which provided a scientific basis for improving the safety standards of Reduning Injection.
Spectroscopy, Near-Infrared/methods* ; Drugs, Chinese Herbal/administration & dosage* ; Machine Learning ; Algorithms ; Humans ; Quality Control

This study aims to explore the mechanism of Jiaotai Pills in treating depression based on metabolomics and network pharmacology. The chemical constituents of Jiaotai Pills were identified by UHPLC-Orbitrap Exploris 480, and the targets of Jiaotai Pills and depression were retrieved from online databases. STRING and Cytoscape 3.7.2 were used to construct the protein-protein interaction network of core targets of Jiaotai Pills in treating depression and the "compound-target-pathway" network. DAVID was used for Gene Ontology(GO) function and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analyses of the core targets. The mouse model of depression was established with chronic unpredictable mild stress(CUMS) and treated with different doses of Jiaotai Pills. The behavioral changes and pathological changes in the hippocampus were observed. UHPLC-Orbitrap Exploris 120 was used for metabolic profiling of the serum, from which the differential metabolites and related metabolic pathways were screened. A "metabolite-reaction-enzyme-gene" network was constructed for the integrated analysis of metabolomics and network pharmacology. A total of 34 chemical components of Jiaotai Pills were identified, and 143 core targets of Jiaotai Pills in treating depression were predicted, which were mainly involved in the arginine and proline, sphingolipid, and neurotrophin metabolism signaling pathways. The results of animal experiments showed that Jiaotai Pills alleviated the depression behaviors and pathological changes in the hippocampus of the mouse model of CUMS-induced depression. In addition, Jiaotai Pills reversed the levels of 32 metabolites involved in various pathways such as arginine and proline metabolism, sphingolipid metabolism, and porphyrin metabolism in the serum of model mice. The integrated analysis showed that arginine and proline metabolism, cysteine and methionine metabolism, and porphyrin metabolism might be the key pathways in the treatment of depression with Jiaotai Pills. In conclusion, metabolomics combined with network pharmacology clarifies the antidepressant mechanism of Jiaotai Pills, which may provide a basis for the clinical application of Jiaotai Pills in treating depression.
Animals ; Drugs, Chinese Herbal/chemistry* ; Depression/genetics* ; Mice ; Network Pharmacology ; Metabolomics ; Male ; Disease Models, Animal ; Humans ; Protein Interaction Maps/drug effects* ; Antidepressive Agents

Eight amide alkaloids(1-8) were isolated from the 70% ethanol extract of Cannabis Fructus using silica gel column chromatography, MCI column chromatography, and semi-preparative high-performance liquid chromatography(HPLC). Their structures were identified as hempspiramide A(1), N-[(4-hydroxyphenyl)ethyl]formamide(2), N-acetyltyramide(3), N-trans-p-coumaroyltyramine(4), N-trans-caffeoyltyramine(5), N-trans-feruloyltyramine(6), N-cis-p-coumaroyltyramine(7), N-cis-feruloyltyramine(8) by using spectroscopic methods such as NMR and MS. Among these compounds, compound 1 was a new amide alkaloid, while compounds 2 and 3 were isolated from Cannabis Fructus for the first time. Some of the isolates were assayed for their α-glucosidase inhibitory activity. Compounds 5-7 displayed significant inhibitory activity against α-glucosidase with IC_(50) values ranging from 1.07 to 4.63 μmol·L~(-1).
Cannabis/chemistry* ; Alkaloids/pharmacology* ; Amides/isolation & purification* ; Drugs, Chinese Herbal/isolation & purification* ; Fruit/chemistry* ; Molecular Structure ; alpha-Glucosidases/chemistry* ; Chromatography, High Pressure Liquid

The chemical constituents of the chloroform extract of the 90% methanol extract obtained from the dried branches and leaves of Croton lauioides were investigated. By using silica gel column chromatography, C_(18 )column chromatography, MCI column chromatography, and semi-preparative high-performance liquid chromatography(HPLC), six compounds were isolated. Their structures were identified as lauioidine(1), 2α-methoxy-8α-hydroxy-6-oxogermacra-1(10),7(11)-dien-8,12-olide(2), myrrhanolide B(3), gossweilone(4), 6β,7β-epox-4α-hydroxyguaian-10-ene(5), and 4(15)-eudesmane-1β,5α-diol(6) by analyzing the HR-ESI-MS, IR, ECD, 1D NMR and 2D NMR data, as well as their physicochemical properties. All compounds were isolated from C. lauioides for the first time, among which compound 1 is a new nor-clerodane diterpenoid.
Croton/chemistry* ; Diterpenes, Clerodane/isolation & purification* ; Molecular Structure ; Drugs, Chinese Herbal/isolation & purification* ; Magnetic Resonance Spectroscopy ; Chromatography, High Pressure Liquid

This study investigated the therapeutic effects and mechanisms of Modified Yiyi Fuzi Baijiang Powder on ulcerative colitis(UC) in rats from the perspective of dampness. SD rats were randomly allocated into six groups(n=10): control, model, mesalazine, and Modified Yiyi Fuzi Baijiang Powder at low(3.96 g·kg~(-1)·d~(-1)), medium(7.92 g·kg~(-1)·d~(-1)), and high(15.84 g·kg~(-1)·d~(-1)) doses. UC was induced in all groups except the control by administration with 3% dextran sulfate sodium(DSS) solution for 7 days. The disease activity index(DAI) was recorded, and the colon tissue was collected for analysis. Histopathological changes were assessed by hematoxylin-eosin staining. Serum levels of D-lactic acid(D-LA) and diamine oxidase(DAO) were measured by ELISA. Immunohistochemistry and PCR were employed to evaluate the expression of aquaporins(AQP3, AQP4) and tight junction proteins [zonula occludens-1(ZO-1) and occludin] at both protein and mRNA levels. Compared with the control group, the model group showed an increased DAI scores(P<0.05), intestinal mucosal damage, elevated serum levels of DAO and D-LA(P<0.05), and decreased expression of AQP3, AQP4, ZO-1, and occludin(P<0.05). Treatment with Modified Yiyi Fuzi Baijiang Powder reduced the DAI scores(P<0.05), lowered the serum levels of D-LA and DAO(P<0.05), and upregulated the expression of AQP3, AQP4, ZO-1, and occludin at both protein and mRNA levels compared with the model group. These findings suggest that Modified Yiyi Fuzi Baijiang Powder exerts therapeutic effects on UC by reducing the intestinal mucosal permeability, promoting colonic mucosal repair, and regulating abnormal intestinal water metabolism, which may involve the upregulation of AQP3 and AQP4 expression.
Animals ; Colitis, Ulcerative/genetics* ; Drugs, Chinese Herbal/administration & dosage* ; Rats, Sprague-Dawley ; Rats ; Intestinal Mucosa/metabolism* ; Male ; Aquaporin 3/metabolism* ; Aquaporin 4/metabolism* ; Permeability/drug effects* ; Humans ; Powders ; Intestinal Barrier Function