Organoid-on-a-chip technology represents a promising interdisciplinary advancement that merges two cutting-edge biomedical platforms: stem cell-derived organoids and microfluidics-based organ-on-a-chip systems. Organoids are self-organizing three-dimensional (3D) cell cultures that mimic the key structural and functional features of in vivo organs. However, traditional organoid culture systems are often static, lacking dynamic environmental cues and suffering from limitations such as batch-to-batch variability, low stability, and low throughput. Organ-on-a-chip platforms, by contrast, utilize microfluidic technologies to simulate the dynamic physiological microenvironment of human tissues and organs, enabling more controlled cell growth and differentiation. By integrating the advantages of organoids and organ-on-a-chip technologies, organoid-on-a-chip systems transcend the limitations of conventional 3D culture models, offering a more physiologically relevant and controllable in vitro platform. In organoid-on-a-chip systems, stem cells or pre-formed organoids are cultured in micro-engineered environments that mimic in vivo conditions, enabling precise control over fluid flow, mechanical forces, and biochemical cues. Specifically, these platforms employ advanced strategies including bio-inspired 3D scaffolds for structural support, precise spatial cell patterning via 3D bioprinting, and integrated biosensors for real-time monitoring of metabolic activities. These synergistic elements recreate complex extracellular matrix signals and ensure high structural fidelity. Based on structural complexity, organoid-on-a-chip systems are classified into single-organoid and multi-organoid types, forming a trajectory from unit biomimicry to systemic simulation. Single-organoid chips focus on highly biomimetic units by integrating vascular, immune, or neural functions. Multi-organoid chips simulate inter-organ crosstalk and systemic homeostasis, advancing complex disease modeling and PK/PD evaluation. This emerging technology has demonstrated broad application potential in multiple fields of biomedicine. Organoid-on-a-chip systems can recapitulate organ developmentin vitro, facilitating research in developmental biology. They mimic organ-specific physiological activities and mechanisms, showing promising applications in regenerative medicine for tissue repair or replacement. In disease modeling, they support the reconstruction of models for neurodegenerative, inflammatory, infectious, metabolic diseases, and cancers. These platforms also enable in vitro drug testing and pharmacokinetic studies (ADME). Patient-derived chips preserve genetic and pathological features, offering potential for precision medicine. Additionally, they reduce species differences in toxicology, providing human-relevant data for environmental, food, cosmetic, and drug safety assessments. Despite progress, organoid-on-a-chip systems face challenges in dynamic simulation, extracellular matrix (ECM) variability, and limited real-time 3D imaging, requiring improved materials and the integration of developmental signals. Current bottlenecks also include the high technical threshold for automation and the lack of standardized validation frameworks for regulatory adoption. Meanwhile, the concept of a “human-on-a-chip” has been proposed to mimic whole-body physiology by integrating multiple organoid modules. This approach enables systemic modeling of drug responses and toxicity, with the potential to reduce animal testing and revolutionize drug development. Future advancements in bio-responsive hydrogels and flexible biosensors will further empower these platforms to bridge the gap between bench-side research and personalized clinical interventions. In conclusion, organoid-on-a-chip technology offers a transformative in vitro model that closely recapitulates the complexity of human tissues and organ systems. It provides an unprecedented platform for advancing biomedical research, clinical translation, and pharmaceutical innovation. Continued development in biomaterials, microengineering, and analytical technologies will be essential to unlocking the full potential of this powerful tool.

Organoid-on-a-chip technology represents a promising interdisciplinary advancement that merges two cutting-edge biomedical platforms: stem cell-derived organoids and microfluidics-based organ-on-a-chip systems. Organoids are self-organizing three-dimensional (3D) cell cultures that mimic the key structural and functional features of in vivo organs. However, traditional organoid culture systems are often static, lacking dynamic environmental cues and suffering from limitations such as batch-to-batch variability, low stability, and low throughput. Organ-on-a-chip platforms, by contrast, utilize microfluidic technologies to simulate the dynamic physiological microenvironment of human tissues and organs, enabling more controlled cell growth and differentiation. By integrating the advantages of organoids and organ-on-a-chip technologies, organoid-on-a-chip systems transcend the limitations of conventional 3D culture models, offering a more physiologically relevant and controllable in vitro platform. In organoid-on-a-chip systems, stem cells or pre-formed organoids are cultured in micro-engineered environments that mimic in vivo conditions, enabling precise control over fluid flow, mechanical forces, and biochemical cues. Specifically, these platforms employ advanced strategies including bio-inspired 3D scaffolds for structural support, precise spatial cell patterning via 3D bioprinting, and integrated biosensors for real-time monitoring of metabolic activities. These synergistic elements recreate complex extracellular matrix signals and ensure high structural fidelity. Based on structural complexity, organoid-on-a-chip systems are classified into single-organoid and multi-organoid types, forming a trajectory from unit biomimicry to systemic simulation. Single-organoid chips focus on highly biomimetic units by integrating vascular, immune, or neural functions. Multi-organoid chips simulate inter-organ crosstalk and systemic homeostasis, advancing complex disease modeling and PK/PD evaluation. This emerging technology has demonstrated broad application potential in multiple fields of biomedicine. Organoid-on-a-chip systems can recapitulate organ developmentin vitro, facilitating research in developmental biology. They mimic organ-specific physiological activities and mechanisms, showing promising applications in regenerative medicine for tissue repair or replacement. In disease modeling, they support the reconstruction of models for neurodegenerative, inflammatory, infectious, metabolic diseases, and cancers. These platforms also enable in vitro drug testing and pharmacokinetic studies (ADME). Patient-derived chips preserve genetic and pathological features, offering potential for precision medicine. Additionally, they reduce species differences in toxicology, providing human-relevant data for environmental, food, cosmetic, and drug safety assessments. Despite progress, organoid-on-a-chip systems face challenges in dynamic simulation, extracellular matrix (ECM) variability, and limited real-time 3D imaging, requiring improved materials and the integration of developmental signals. Current bottlenecks also include the high technical threshold for automation and the lack of standardized validation frameworks for regulatory adoption. Meanwhile, the concept of a “human-on-a-chip” has been proposed to mimic whole-body physiology by integrating multiple organoid modules. This approach enables systemic modeling of drug responses and toxicity, with the potential to reduce animal testing and revolutionize drug development. Future advancements in bio-responsive hydrogels and flexible biosensors will further empower these platforms to bridge the gap between bench-side research and personalized clinical interventions. In conclusion, organoid-on-a-chip technology offers a transformative in vitro model that closely recapitulates the complexity of human tissues and organ systems. It provides an unprecedented platform for advancing biomedical research, clinical translation, and pharmaceutical innovation. Continued development in biomaterials, microengineering, and analytical technologies will be essential to unlocking the full potential of this powerful tool.

Objective To analyze the monitoring data of ¹³¹I internal exposure in Guangdong Province over the past 3 years, study the thyroid ¹³¹I contamination levels among nuclear medicine staff, and provide a basis for optimizing the monitoring plan. Methods Using a convenience sampling method, 574 detections of nuclear medicine staff from 28 hospitals in Guangdong Province were included in the study. The thyroid ¹³¹I activity was measured directly in vivo. Differences in detection rates were analyzed, and committed effective doses were estimated. Results Over the past 3 years in Guangdong Province, ¹³¹I accumulation was found in the thyroids of staff from 14 hospitals for 62 (10.8%) detections, with an average activity of 154.8 (13.2-8730.6) Bq. The adjusted annual intake was 50.7 (4.5-820.6) kBq. The committed effective dose was 0.56 (0.05-9.03) mSv/a, and the values were ≥ 2 mSv for 8 persons. Among different positions, nurses showed the highest detection rate (19.6%), followed by cleaners (14.7%), with significant differences (P<0.05). Among different exposure types, the detection rate was highest for loading medication into automatic dispenser (23.3%), and the mean activity was highest for entering thyroid cancer patient ward (495.4 Bq), with significant differences (P<0.05). Conclusion Monitoring of ¹³¹I internal exposure in Guangdong Province found that the radiation doses of some staff members had exceeded the threshold specified in other investigations. Routine personal ¹³¹I internal exposure monitoring should be conducted, with increased monitoring frequency. Priority should be given to nurses and cleaners, with monitoring extended to cleaners and outsourced dispensing staff.

Objective:To analyze the current situation of health-related quality of life (HRQOL) and its influencing factors among community-dwelling elderly with mild cognitive impairment (MCI) based on the health ecology model (HEM).Methods:From December 2023 to September 2024, a cross-sectional survey was conducted among 997 community-dwelling elderly in Beijing, Shandong, Chongqing and other regions. The EuroQol five-dimensional questionnaire 5 level (EQ-5D-5L), the Montreal cognitive assessment (MoCA), and the Pittsburgh sleep quality index (PSQI) were used to assess the subjects.Descriptive analysis, Mann-Whitney U test, Kruskal-Wallis test, and Tobit regression analysis were performed using Stata 18.0 software. Results:A total of 324 valid samples were finally obtained, and the health utility value of MCI elderly was 0.842(0.815, 0.951). Tobit regression analysis showed that ≥80 years old( β=-0.121, 95% CI=-0.193--0.050) in individual traits level, don't exercise( β=-0.196, 95% CI=-0.255--0.137) and poor quality of sleep ( β=-0.064, 95% CI=-0.116--0.013) in behavior characteristics level, and poor subjective economic status( β=-0.153, 95% CI=-0.261--0.045) in living and working conditions level were risk factors for the health utility value of the elderly with MCI. Drinking( β=0.096, 95% CI=0.022-0.171) in behavior characteristics level and participating in social activities( β=0.126, 95% CI=0.062-0.190) in interpersonal network level were protective factors for the health utility value of the elderly with MCI. Conclusions:The HRQOL of the community-dwelling elderly with MCI in China is low, and its influencing factors are multi-level. HEM should be combined to strengthen the intervention and management of the elderly with MCI from personal constitution to policy environment to improve their HRQOL.

Aim To investigate the protective effect of Shengmai Yin on myocardial ischemia/reperfusion in-jury(MI/RI)in vitro and in vivo and to unravel the underlying mechanism.Methods SD rats were divid-ed into the sham group,model group,and Shengmai Yin group(SM).Rat MI/RI model was established.Cardiac function,infarct area,pathological changes,cardiomyocyte apoptosis,macrophage infiltration,and serum cTnT and CK-MB levels were measured.The mRNA and protein expressions of Calpain-1 and Cal-pain-2 were assessed.The hypoxia/reoxygenation(H/R)model was constructed in H9c2 cells.The active ingredients of Shengmai Yin were screened using net-work pharmacology and verified by CCK-8.In the car-diomyocytes H/R model,Fluo-4 AM staining was used to detect the changes of Ca2+levels.Results Com-pared with model group,LVEF and LVFS of Shengmai Yin-treated rats increased,myocardial infarction area was reduced,while myocardial tissue injury was allevi-ated.Myocardial apoptosis rate and the number of macrophages were reduced.Similarly,cTnT and CK-MB levels decreased.In addition,the expression lev-els of Calpain-1 and Calpain-2 mRNA and protein de-creased in the SM treatment group.Under the H/R model,all the active ingredients of Shengmai decoction had protective effects on cardiomyocytes,and the treat-ment could reduce the level of Ca2+in cardiomyocytes.Conclusions Shengmai Yin has protective effects on MI/RI in rats.This effect may be related to the de-crease in Ca2+levels,as well as Calpain-1 and Calap-in-2 mRNA and protein expression.

Objective To investigate the effects of Amanita caojizong on cardiomyocyte apoptosis and the expression of apoptosis-related factors Bcl-2 and Bax,thereby providing experimental evidence for the prevention and treatment of Amanita caojizong poisoning.Methods Mouse cardiomyocytes(HL-1 cells)cultured in vitro were divided into an experimental group(treated with Amanita caojizong extract)and a control group(treated with PBS).After treatment with Amanita caojizong extract,apoptosis of HL-1 cells was observed using TUNEL staining,and the protein expression levels of Bax,Bcl-2,Caspase-3,and Cleaved Caspase-3 in HL-1 cardiomyocytes were detected by Western blot.Results Compared with the control group,the TUNEL staining showed significantly increased apoptotic fluorescence intensity in the Amanita caojizong extract-treated group.The protein expressions of Bax,Caspase-3,and Cleaved Caspase-3 in HL-1 cells in the Amanita caojizong-treated group were upregulated,while the expression of Bcl-2 was downregulated.Conclusion Amanita caojizong can promote apoptosis of mouse cardiomyocytes,and its mechanism may be associated with the Bcl-2/Bax pathway.

Objective:To construct a sizeable naive human Fab phage display antibody library to screen high-affinity specific antibodies in vitro. Methods:Total RNA was extracted from peripheral blood mononuclear cells (PBMCs) of 126 healthy individuals, subsequently reverse-transcribed into cDNA, and used as a template. PCR amplification was performed to obtain the V H from IgG, IgM and light chain κ, λ, separately, with the initial PCR products serving as templates for a second round of PCR. Overlap extension PCR was employed to generate fragments of the κ and λ light chains. These fragments were ligated with the phage vector pNC3, which harbors the variable region 1 of the heavy chain, to construct a recombinant phage plasmid. This plasmid was then electroporated into competent Escherichia Coli TG1 cells to establish a naive human Fab phage display antibody library. One hundred clones were randomly selected for identification and sequencing, and antibody gene polymorphisms were analyzed using the IMGT database and MAFFT software. Recombinant α-hemolysin from Staphylococcus aureus was utilized to screen Fab antibody fragments through biopanning of the antibody library, followed by random selection of phage ELISA-identified clones. The positive clones (antigen A450∶blank control A450≥2.1) were sequenced. Results:Two large naive Fab phage display antibody libraries were successfully constructed, in which the capacity of κ and λ chain antibody libraries were 1.25×10 11 and 1.54×10 11, respectively. The titers for two antibody libraries were 6.04×10 13 CFU/ml and 3.50×10 13 CFU/ml. The positive transformation insertion rates for κ and λ chain antibody libraries were 96% (96/100) and 100% (100/100), respectively. Sequence analysis revealed that all antibody sequences were unique. The amino acid sequences in the skeletal region were relatively conserved. In contrast, significant variations in the length of the complementarity determining region (CDR) were found, and the diversity of amino acid sequence of the complementary determining region was high, especially the CDR3. Analysis using the IMGT database indicated that the sequences exhibited a broad distribution across variable-diversity-joining gene families. After six rounds of panning, specific phage antibodies enrichment targeting α-hemolysin were achieved. A total of 142 monoclonal antibodies were sequenced, yielding 8 distinct Fab antibody sequences. Conclusion:This study successfully constructed two naive human Fab phage display antibody libraries with large capacity and good diversity, which can be used for screening human antibodies for serum epidemiology.

The prevention and control of emerging and reemerging infectious diseases are crucial for national biosecurity, and surveillance and reporting of pneumonia of unknown etiology are main ways for the early detection of these diseases and mitigation of their severity. This paper summaries the surveillance methods for pneumonia of unknown etiology and emerging and reemerging infectious diseases globally, indicating that such surveillance is mainly conducted based on hospital. Western countries primarily combine active and passive surveillance while utilizing artificial intelligence technology to rapidly identify cases. China mainly use passive surveillance based on the surveillance system for pneumonia of unknown etiology, with the function of early warning in the identification of emerging infectious diseases, such as avian influenza. However, with the improvement in the surveillance system operation, the overlap with other surveillance disease systems, such as influenza, has occurred, and the improvements in case definition and operational protocol are needed. It is recommended to improve the specificity of the case definition, strenthen training in hospital staff, inclduing clinical workers and office workers, and formulate incentive mechanisms. It is necessary to emphasize the responsibility of clinicians as the main force for the detection and reporting of pneumonia of unknown etiology and emerging infectious diseases, improve the appilication of artifical intelligent technique and conduct multi-source surveillance, such as third-party testing.

Objective To evaluate the value of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)in differentiating histopathological types of brain metastases from non-small cell lung cancer(NSCLC).Methods Sixty-eight patients with brain metastases confirmed by pathology were collected,including 47 lung adenocarcinoma patients divided into a lung adenocarcinoma group and 21 lung squamous cell carcinoma patients into a lung squamous cell carcinoma group.The two groups were compared in terms of the DCE-MRI derived parameters including volume transfer constant(Ktrans),extra vascular extracellular volume fraction(Ve)and plasma volume fraction(Vp);ROC curves were used to assess the diagnostic efficacy of different quantitative parameters for the pathologic types of brain metastases from lung adenocarcinoma group or lung squamous cell carcinoma.SPSS 22.0 software was used for statistical analysis.Results The lung adenocarcinoma group had the values of Ktrans,Ve,Vp and Ve+Vp higher than those of the lung squamous cell carcinoma group,with the differences being statistically significant(all P＜0.05).ROC curve analysis results showed that Ktrans,Vp and Ve had high differential diagnosis values for the pathologic types of brain metastases from lung adenocarcinoma group or lung squamous cell carcinoma,with the AUC being 1.000,0.998 and 0.875,the optimal Youden index being 0.183 min-1,0.039 and 0.270,the sensitivity being 100.00％,100.00％and 80.56％and the specificity being 100.00％,97.06％and 80.88％,respectively.Conclusion The quantitative parameters of DCE-MRI gain advantages in the differential diagnosis of NSCLC brain metastases,and provide references for the diagnosis and treatment of brain metastases of lung cancer.[Chinese Medical Equipment Journal,2025,46(5):54-59]

Aortic regurgitation and mitral regurgitation are more common in elderly heart valve disease,and both may be present in some patients.Severe aortic regurgitation complicated with severe mitral regurgitation often requires surgical valve replacement,but in patients at high risk of surgery,the risk of perioperative mortality is significantly increased.Therefore,for such patients,minimally invasive interventions can significantly improve long-term patient outcomes while reducing surgical risk.This article report a case of transcatheter aortic valve replacement combined with transcatheter edge-to-edge repair in the treatment of severe aortic regurgitation combined with mitral valve prolapse,in order to explore new treatment ideas for similar cases.