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.

Boron neutron capture therapy (BNCT) is a precision radiotherapy technology for tumors. On the international stage, Japan stands out as a representative country where BNCT has progressed into a mature clinical phase. Although China started relatively late, it has achieved rapid advancements through independent research and development in accelerator and neutron source equipment, domestically produced boron drugs, and clinically validated therapeutic efficacy. In several key indicators, China has now reached internationally advanced levels. Looking ahead, efforts should be prioritized toward the development of third-generation boron-based drugs, the standardization of treatment protocols, and cost reduction to enhance treatment accessibility, ultimately aiming to build a competitive BNCT clinical application and technological innovation system.

Objective:To compare the types and contents of trace elements in compound trace element preparations used in parenteral nutrition in Beijing against the doses recommended by the guidelines, so as to facilitate optimal choice of preparations for different populations in clinical practice.Methods:The available compound trace element preparations were determined according to the drug list from the Medical Insurance Recruitment and Procurement System of Beijing and the recommended doses of trace elements in the guidelines released by Chinese domestic and foreign nutrition societies were collected and compared.Results:The compound trace element preparations used in Beijing comprised 4 varieties and 6 specifications, with the daily cost ranging from 11.32 to 471 Chinese Yuan. There were 3 varieties of trace element preparations for adults, including multi-trace elements injection (Ⅱ), multi-trace elements injection (Ⅲ), and multi-trace elements injection. Among those, multi-trace elements injection (Ⅲ) met the guideline recommendations best and the price was moderate. For pediatric populations, multi-trace elements injections (Ⅰ) satisfied better the trace element requirements for preterm infants and infants from term to 3 months, while multi-trace elements injections (Ⅲ) outperformed in meeting the trace element requirements for 3-to-12-month infants and children. However, there were still some differences in the trace element contents between the two preparations and the guideline recommendations.Conclusion:The currently available varieties and specifications of trace element preparations basically meet the recommendations of evidence-based guidelines, but there is still the need to improve the instructions for and evidence on the pediatric application of certain preparations.

Objective:An inceasing number of commercial multi-chambered bag products for parenteral nutrition (PN) have been launched in China, with some being included in the National Medical Insurance Catalogue (NMIC). In this study, the commercially available triple-chambered bag (3CB) products for PN in China were comprehensively analyzed in terms of basic characteristics, applicable population, and costs to guide the rational use of these products in clinical settings.Methods:The marketing information of 3CB products was collected. The inclusion of these products in NMIC and the Catalogue of Selected Drugs for National Centralized Procurement was investigated, along with the collection of manufacturer's instructions and pricing information in Beijing. Two researchers extracted and calculated the information of 3CB products, including energy density, types and levels of each component, glycolipid ratio, osmotic pressure, and price. The applicable population and economy of these products were also compared.Results:As of April 2024, 11 3CB products, including 23 specifications, had been approved in China. Eight products were included by NMIC and 2 by the Catalogue of Selected Drugs for National Centralized Procurement. The energy density, protein content, and lipid content dramatically differed among 3CB products (energy density, 254.0–493.7 kJ/100 ml; protein, 2.2–5.6 g/100ml; lipid, 2–4 g/100 ml; and glycolipid ratio, 62∶38–40∶60). Five products could only be infused via the central veins. The sources of fat emulsions included soybean oil-based long-chain fat-milk, medium-long-chain fat-milk, olive oil-based fat-milk, and fish oil-based fat-milk. All the 3CB products contained 8 essential amino acids and some non-essential amino acids, with or without tyrosine, taurine, aspartic acid, and glutamic acid. The average daily total cost of 3CB PN was 74.78–585.82 yuan. Since Some 3CB products had been listed in NMIC, they were affordable for urban patients covered by Urban Employee Basic Medical Insurance but might be economically unacceptable for rural residents who are insured by the Basic Medical Insurance for Urban and Rural Residents and uninsured patients. Conclusions:A variety of 3CB products have been commercially available in China and can meet the individual PN needs of most patients. Although some products have been listed by NMIC, the economic burden can be heavy for certain patient populations.

Objective To explore the damage results and structural response laws of medical cabins in ships under explosion attack.Methods Firstly,the cabin structure was equivalently regarded as a T-shaped plate frame based on the explosion load theory,then four finite element models for the medical cabins were established with the dimensions(length ×width×height)of 2.8 m×2.6 m×2.3 m,3.2 m×3.2 m×2.4 m,4.2 m×3.2 m×2.5 m and 5.4 m×4.0 m×2.6 m.Secondly,an explosion damage model was constructed using ABAQUS simulation software,and explosion damage simulation was carried out with the explosion locating at the cabin center and the outside of the bulkhead and the explosion energy of 10 kg and 100 kg trinitrotoluene(TNT)equivalent.Finally,the 10 kg and 100 kg TNT explosion damage results were ananlyzed at the cabin center and the outside of the bulkhead.Results At the cabin center,10 kg TNT explosion resulted in local deformation and limited affected area of the large-sized cabin,while 100 kg TNT explosion lead to extensive affected ranges in the functional areas and severe deformation and damage in the small-sized cabin.At the outside of the bulkhead,10 kg TNT explosion gave rise to breaches in some areas of the small-sized cabin and local deformation of the large-sized cabin,while 100 kg TNT explosion caused large breaches in all the cabins.Conclusion The explosion load induces serious deformation and damage and complicated breaches in the cabin with small size and weak structural strength.The cabin with large size and thick bulkhead and stiffener behaves well in explosion resistance,while high equivalent explosions may bring about serious damage to its local structure.[Chinese Medical Equipment Journal,2025,46(1):27-32]

The purpose of this survey was to understand the occurrence of hypocalcemia in dairy cows in large-scale pasture and its relationship with production performance,disease and culling.Eighty-one large-scale pastures were selected in China to carry out a questionnaire survey on the lactation performance,reproductive performance,disease status and culling situations of dairy cows,and analyzed the production data of dairy farms by SPSS software.The survey results show that the incidence of hypocalcemia in dairy cows in pasture was different,the subclinical type was nearly twice as high as the clinical type,and the incidence rate of hypocalcemia was higher in about 30％of pasture.Hypocalcemia has no obvious effect on the lactation performance of dairy cows on dairy farms.However,a high incidence rate can reduce the conception rate,increase the incidence of subclinical mastitis,ketosis,and other common internal diseases,and raise the annual culling rate and culling rate of adult cows.Clinical,subclinical and total incidence of hypocalcemia have differ-ent effects on reproduction and diseases such as mastitis and ketosis,but clinical hypocalcemia is more harmful.Hypocalcemia is still an important metabolic disease that harms the health and pro-duction of dairy cows in large-scale pastures in China.For farms with a high incidence rate,it is recommended to conduct regular monitoring of blood calcium levels in dairy cows before and after calving,and to conduct in-depth investigations into the related pathogenic factors.This will provide a scientific basis for improving the prevention measures for hypocalcemia,reducing the incidence of the disease,increasing reproductive efficiency,and reducing culling rates.

Objective:Non-targeted metabolomics based on ultra-performance liquid chromatography mass spectrometry(UPLC-MS)platform was used to study the metabolic characteristics of multiple myeloma(MM)patients,and explore potential new metabolic mechanisms affecting the occurrence and development of MM.Methods:The study enrolled 42 MM patients,including 21 newly diagnosed(ND)patients and 21 relapsed patients(RP),and 21 age-sex matched healthy controls(HC)as subjects.UPLC-MS analysis platform was used to detect small molecule metabolites in serum of the subjects.Principal component analysis(PCA),orthogonal partial least-squared discriminant analysis(OPLS-DA)and 200 random permutations were used to analyze the differences of metabolic profiles among groups.Identification of differential metabolites was completed in the Human Metabolome Database(HMDB)and abnormal metabolic pathway analysis was performed using the KEGG database.Results:The metabolic profiles of MM patients and healthy controls were significantly separated in both PCA and OPLS-DA models,while the metabolic profiles of newly diagnosed and relapsed MM patients were significantly separated only in OPLS-DA model.In ND vs HC,RP vs HC and RP vs ND cohorts,19,24 and 18 differential metabolites were identified respectively,mainly sphingolipids,glycerophospholipids and fatty acyl amino acids.The metabolic pathway abnormalities in newly diagnosed and relapsed MM patients were mainly manifested in sphingolipid metabolism and glycerophospholipid metabolism compared to healthy controls.Compared with newly diagnosed MM patients,relapsed MM patients were mainly manifested in sphingolipid metabolism and ether-lipid metabolism.Conclusion:The metabolic profiles of MM patients are significantly different from those of healthy people.Relapsed MM patients and newly diagnosed MM patients have similar metabolic profiles,but there are still some differences.Glycerophospholipid metabolism,sphingolipid meta-bolism and ether-lipid metabolism may play important biological roles in the occurrence and development of MM.

Objective:To explore the application of the flipped classroom teaching method in pediatric internship, evaluate the feedback from both students and faculty, and provide evidence for optimizing clinical medical education strategies.Methods:Fourth-year students ( n=174) enrolled in 2019 in the eight-year clinical medicine program at Peking University Health Science Center and instructors ( n=42) participated in this study. Questionnaire survey and exit examination scores were used to assess the effectiveness of the flipped classroom method. A statistical analysis was performed using SPSS 26.0. Kruskal-Wallis test and Dunn's multiple comparisons were used to evaluate the differences in satisfaction across teaching components. Chi-square test and Fisher's exact test were applied to compare satisfaction between high-score (top 30%) and low-score (bottom 30%) student groups. Results:①Overall student satisfaction with the flipped classroom reached 91.33% ("very satisfied" + "satisfied"). High satisfaction was reported for pre-class self-learning videos (80.35%), recommended clinical guidelines (82.80%), and English literature (71.10%), while satisfaction with the flipped classroom lectures was comparatively low (52.60%), with significant differences compared to other components ( P<0.05). ②High-score students exhibited significantly lower satisfaction than low-score students across all components (overall evaluation, 84.61% vs. 98.08%, Fisher's exact test, P=0.031; pre-class videos, 53.85% vs. 76.92%, χ2=6.12, P=0.013; preparatory assignments, 61.54% vs. 80.77%, χ2=4.68, P=0.030; English literature, 53.85% vs. 75.00%, χ2=5.80, P=0.016; and flipped class lectures, 36.54% vs. 59.62%, χ2=5.55, P=0.019). ③Enhanced competency in ≥2 core areas was reported in 71.68% of students, including theoretical knowledge acquisition (49.71%), self-directed learning (35.84%), clinical thinking (31.21%), research capabilities (25.43%), and communication skills (22.54%). ④Faculty feedback indicated that 83.33% of instructors perceived the flipped classroom as equivalent or superior to traditional teaching, particularly in cultivating clinical thinking (90.48%), self-directed learning (85.71%), theoretical knowledge acquisition (76.19%), and communication skills (76.19%). ⑤Student participation willingness was primarily influenced by pre-class time investment (46.51% reported excessive effort in preparing discussion materials), while faculty engagement depended on implementation effectiveness (42.86%) and curriculum design (35.71%). Conclusions:The flipped classroom method demonstrated promising initial outcomes in pediatric internship, with high satisfaction among both students and faculty. However, further exploration and practice are required in optimizing teaching components, implementing differentiated instructional strategies, and managing time investment.

A rapid and accurate method for textile fiber identification was developed for quality control and consumer protection.This method utilized electric soldering iron burning-mesh collision enhanced microtube plasma ionization mass spectrometry(ESIB-MC-μTP-MS)to acquire textile fiber MS data and used a random forest(RF)prediction model to identify fiber composition based on these MS data.The MC-μTP device involved in the method was a homemade low-temperature plasma ionization device constructed using cost-effective and readily available components.The system was applicable for direct analysis of small amount of textile samples without any complex sample pretreatment processes.Characteristic thermal decomposition products of different fibers were generated via soldering iron burning(350℃)in ambient atmosphere,and were subsequently analyzed by a mass spectrometer,with each analysis completed within 5 s.Raw MS data underwent noise reduction,normalization,and global binning steps to form a dataset,and its intrinsic class separability was evaluated using principal component analysis(PCA)combined with k-means clustering.Then,the RF model was trained based on the dimensionality-reduced textile fiber dataset.After grid search optimization,this model demonstrated robust performance with a 0.9762 out-of-bag score,a 0.9683 cross-validation accuracy(5-fold),and a 0.9636 test accuracy,supported by precision,recall,and F1-scores exceeding 0.889 for all fiber classes.The method was applied to analysis of 30 luxury apparel samples from eight brands,among which 20 samples achieved 100%prediction confidence,aligning with labeled compositions.The identification result of two low-confidence samples was further confirmed using attenuated total reflection Fourier transform infrared spectroscopy(ATR-FT-IR).The method has been proven to be simple,portable and with minimal sample requirements for on-site customs inspections,providing a viable tool in the fight against counterfeit products,therefore supporting regulatory enforcement and consumer trust in the textile goods market.

Due to the poor ionization efficiency and the weak mass spectrometry(MS)intensity of weakly polar substances,direct analysis using the traditional electrospray ionization mass spectrometry(ESI-MS)is a big challenge.In this study,a novel rapid on-site detection method of four prohibited sex hormones in cosmetics was proposed using online derivatization strategy coupled with a miniature mass spectrometer.The target substances in the samples were extracted by a custom-made polyaniline/multi-walled carbon nanotube solid-phase microextraction(SPME)probe.The stirring speed was 200 r/min,the extraction temperature was 40℃,and the extraction time was 2 min.A pulled dual-channel θ borosilicate glass capillary emitter was used as the nano-ESI ion source.The SPME probe was inserted into the channel containing methanol in theθborosilicate glass capillary.When the spray voltage was applied,the four sex hormones were desorbed and formed spray microdroplets,which then collided with the hydroxylamine microdroplets generated from the other channel.The microdroplets of reaction product entered into the miniature mass spectrometer for direct analysis.The limits of detection(LOD)and limits of quantification(LOQ)for the four sex hormones were 10-20 ng/mL and 20-50 ng/mL,respectively.The recoveries were from 84.6%to 107.8%with the relative standard deviations(RSD)from 4.1%to 11.6%.Compared to detection without derivatization,the MS signals of the four target substances were increased by 3 to 15 times.This method was simple,rapid,highly efficient and sensitive,and suitable for on-site rapid analysis of weakly polar sex hormones in cosmetics.