BACKGROUND:Periprosthetic fracture of the femoral of the knee after total knee arthroplasty is one of the common complications,and there is a lack of biomechanical research on the periprosthetic fractures of the femoral of the knee under different bone strength conditions.The three-dimensional finite element analysis can provide a biomechanical basis for clinical practice. OBJECTIVE:To investigate the biomechanical changes of anterior femoral notching after total knee arthroplasty under different bone strengths,and to provide a mechanical basis for the clinical prevention of supracondylar femoral periprosthetic fractures after knee arthroplasty. METHODS:The femoral CT data of healthy adults were obtained,and the three-dimensional model of femoral lateral replacement of the knee joint was established by Mimics,Geomagic studio,and Solidworks software.Anterior femoral notching models of different depths were constructed,and the models were imported into ANSYS software to analyze the changes of biological stress on the femoral condyle with different bone strengths and different anterior femoral notching depths.The stress changes of the femoral anterior condyle section after and before the filling of anterior femoral notching with bone cement were analyzed. RESULTS AND CONCLUSION:(1)Under any bone strength,the supracondylar stress increased with the depth of anterior femoral notching.In normal bone conditions,there was a stress abrupt change point when the anterior femoral notching depth was between 3 mm and 4 mm.In the case of osteoporosis,there was a stress abrupt point when the anterior femoral notching depth was between 2 mm and 3 mm.(2)When anterior femoral notching occurred during knee arthroplasty and the depth exceeded the thickness of the bone cortex,the supracondylar stress of the femoral gradually increased as the bone strength decreased.(3)The stress of the anterior femoral condyle section decreased when the model with an anterior femoral notching depth of 3 mm was filled with bone cement.(4)The results show that anterior femoral notching should be avoided during knee arthroplasty,especially in patients with osteoporosis.If anterior femoral notching occurs during surgery,bone cement can be used to evenly fill the anterior femoral notching to reduce the supracondylar stress of the femur and reduce the incidence of periprosthetic fractures of the femoral joint

Lipocalin-2 (LCN2), a member of the human lipocalin family, has been demonstrated to be closely associated with diabetes, cardiovascular diseases, and renal disorders. Recent studies have indicated that LCN2 plays a significant regulatory role in the pathogenesis and progression of various neurological diseases by mediating pathways such as inflammation, oxidative stress, and ferroptosis. This article reviews the research advancements on the mechanism of LCN2 in neurological disorders, including cerebrovascular diseases, cognitive impairment disorders, Parkinson's disease, depression, and anxiety disorders, aiming to enhance clinical understanding.

Objective To investigate the impact of Toxoplasma gondii type I, II and III rhoptry protein 16 (ROP16) on programmed cell death ligand 1 (PD-L1) expression in lung adenocarcinoma cells, and to examine the effects of T. gondii type I ROP16 protein on the relative PD-L1 expression, the relative PD-L1 distribution on the cell membrane surface, and the binding of programmed cell death 1 (PD-1) to PD-L1 in lung adenocarcinoma cells. Methods Lentiviral vectors overexpressing T. gondii type I, II and III ROP16 proteins were generated, and transfected into the human lung adenocarcinoma A549 cell line. A549 cells were used as a blank control group, and A549 cells transfected with an empty lentiviral expression vector were used as a negative control group, while A549 cells transfected with lentiviral vectors overexpressing T. gondii type I, II and III ROP16 proteins served as experimental groups. Stably transfected cells were selected with puromycin and verified using Western blotting, quantitative real-time PCR (RT-qPCR), and immunofluorescence assays. The PD-L1 expression was quantified at translational and transcriptional levels using Western blotting and RT-qPCR assays in A549 cells in the five groups, and the relative PD-L1 distribution was detected on the A549 cell membrane surface using flow cytometry. In addition, the effect of T. gondii type I ROP16 protein on the PD-1/PD-L1 binding was measured in A549 cells using enzyme-linked immunosorbent assay (ELISA). Results The relative ROP16 protein expression was 0, 0, 1.546 ± 0.091, 1.822 ± 0.047 and 2.334 ± 0.089 in the blank control group, negative control group, and the T. gondii type I, II and III ROP16 protein overexpression groups (F = 1 339.00,P < 0.001), and the relative ROP16 mRNA expression was 2.153 ± 0.949, 2.436 ± 1.614, 14.343 ± 0.020, 12.577 ± 0.285 and 15.090 ± 0.420 in the blank control group, negative control group and the T. gondii type I, II and III ROP16 protein overexpression groups, respectively (F = 483.50,P < 0.001). The ROP16 expression was higher in the T. gondii type I, II and III ROP16 protein overexpression groups than in the blank control group at both translational and transcriptional levels (allP values < 0.001). Immunofluorescence assay revealed that T. gondii type I, II and III ROP16 proteins were predominantly localized in A549 cell nuclei. Western blotting showed that the relative PD-L1 protein expression was 0.685 ± 0.109, 0.589 ± 0.114, 1.007 ± 0.117, 0.572 ± 0.151, and 0.426 ± 0.116 in the blank control group, negative control group, and the T. gondii type I, II and III ROP16 protein overexpression groups (F = 9.46,P < 0.05), and RT-qPCR assay quantified that the relative PD-L1 mRNA expression was 1.012 ± 0.190, 1.281 ± 0.465, 1.950 ± 0.175, 0.889 ± 0.251, and 0.230 ± 0.192 in the blank control group, negative control group, and the T. gondii type I, II and III ROP16 protein overexpression groups (F = 14.18,P < 0.05). The PD-L1 expression was higher in the T. gondii type IROP16 protein overexpression group than in the blank control group at both translational and transcriptional levels (both P values < 0.05). Flow cytometry detected that the relative distributions of PD-L1 protein were (10.83 ± 0.60)%, (11.23 ± 0.20)%, and (14.61 ± 0.50)% on the A549 cell membrane surface (F = 28.31, P < 0.05), and the relative distribution of PD-L1 protein was higher in the T. gondii type IROP16 protein overexpression group than in the blank control group and negative control group (both P values < 0.001). ELISA measured significant differences in the absorbance (A) value among the T. gondii type IROP16 protein overexpression group, the blank control group and the negative control group if the concentrations of the recombinant PD-1 protein were 0.04 (F = 10.45, P < 0.05), 0.08 μg/mL (F = 11.68, P < 0.05) and 0.12 μg/mL (F = 52.68, P < 0.05), and the A value was higher in the T. gondii type IROP16 protein overexpression group than in the blank control group and the negative control group (both P values < 0.05), indicating that T. gondii type IROP16 protein promoted the PD-L1/PD-1 binding in A549 cells in a concentration-dose manner. Conclusions T. gondii type IROP16 protein overexpression may up-regulate PD-L1 expression in A549 cells at both transcriptional and translational levels and the relative PD-L1 distribution on the A549 cell membrane surface, and affect the PD-1/PD-L1 binding in a concentration-dependent manner.

Cell models can simulate a variety of life states and disease developments, including single cells, two-dimensional (2D) cell cultures, three-dimensional (3D) multicellular spheroids, and organoids. They are essential tools for addressing complex biochemical questions. With continuous advancements in biological and cellular analysis technologies, in vitro cellular models designed to answer scientific questions have evolved rapidly. Early in vitro models primarily relied on 2D systems, which failed to accurately replicate the complex cellular compositions and microenvironmental interactions observed in vivo, let alone support sophisticated investigations into cellular biological functions. Subsequent improvements in cell culture techniques led to the development of 3D culture-based models, such as cellular spheroids. The advent of pluripotent stem cell technology further advanced the development of organoid systems, which closely mimic human organ development. Compared to traditional 2D models, both 3D cellular models and organoids offer significant advantages, including personalization and enhanced physiological relevance, making them particularly suitable for exploring molecular mechanisms of disease progression, discovering novel cellular and biomolecular functions, and conducting related studies. The imaging analysis of common cellular models primarily employs labeling-based methods for in situ imaging of targeted genes, proteins, and small-molecule metabolites, enabling further research on cell types, states, metabolism, and drug efficacy. However, these approaches have drawbacks such as poor labeling specificity and complex experimental procedures. By using cells as experimental models, mass spectrometry technology combined with morphological analysis can reveal quantitative changes and spatial distributions of various biological substances at the spatiotemporal level, including metabolites, proteins, lipids, peptides, drugs, environmental pollutants, and metals. This allows for the investigation of cell-cell interactions, tumor microenvironments, and cellular bioinformational heterogeneity. The application of these cutting-edge imaging technologies generates vast amounts of cellular data, necessitating the development of rapid, efficient, and highly accurate image data algorithms for precise segmentation and identification of single cells, multi-organelle structures, rare cell subpopulations, and complex cellular morphologies. A critical focus lies in creating deep learning models and algorithms that enhance the accuracy of cellular visualization. At the same time, establishing more robust data integration tools is essential not only for analyzing and interpreting outputs but also for effectively uncovering the biological significance of spatially resolved mass spectrometry data. Developing a cell imaging platform with high versatility, operational stability, and specificity to enable data interoperability will significantly enhance its utility in clinical research, thereby advancing investigations into disease molecular mechanisms and supporting precision diagnostics and therapeutics. In contrast to genomic, transcriptomic, and proteomic information, the metabolome can rapidly respond to external stimuli and cellular physiological changes within a short timeframe. This rapid and precise reflection of ongoing cellular state alterations has positioned spatial metabolomics as a pivotal approach for exploring the molecular mechanisms underlying physiological and pathological processes in cells, tissues, and organisms. In this review, we summarize research on cell imaging based on mass spectrometry technologies, including the selection and preparation of cell models, morphological analysis of cell models, spatial omics techniques based on mass spectrometry, mass cytometry, and their applications. We also discuss the current challenges and propose future directions for development in this field.

Background Due to the unique working environment and numerous occupational disease hazards, workers in mining industry are particularly susceptible to psychological problems such as occupational stress. Objective To understand the current status of occupational stress, depressive symptoms, anxiety symptoms and sleep quality of workers in ferrous and non-ferrous metal mining industry in Gansu Province, and to explore the effects of occupational stress on depressive symptoms, anxiety symptoms, and sleep. Methods From April to December 2022, the workers of 25 large, medium, and small and micro enterprises were selected by stratified cluster random sampling and surveyed in ferrous and non-ferrous metal mining industry in Gansu Province. The Occupational Health Literacy Questionnaire of National Key Population, Core Occupational Stress Scale, Patient Health Questionnaire-q, Generalized Anxiety Disorder, and Self-administer Sleep Questionnaire were used to collect basic information, occupational stress, depressive symptoms, anxiety symptoms, and sleep quality of the workers. Chi-square test was used to compare occupational stress, depressive symptoms, anxiety symptoms and sleep disorders among different categories. Logistic regression model was used to study the effects of occupational stress on depressive symptoms, anxiety symptoms, and sleep quality. Results In this study, 2192 workers in mining industry were surveyed, of which 2087 returned valid questionnaires, and the recovery rate of valid questionnaires was 95.2%. Among them, 728 (38.4%) reported occupational stress. There were statistically significant differences in the positive rate of occupational stress among workers by gender, age, marital status, education level, average monthly income, length of service, enterprise size, and night shifts (P<0.001). The positive rates of depressive symptoms, anxiety symptoms, and sleep disorders in the mining industry workers were 85.6%, 49.8%, and 47.3%, respectively. The positive rates of depressive symptoms, anxiety symptoms, and sleep disorders among workers with higher occupational stress were higher than those among workers without occupational stress (P<0.001). The logistic regression analysis showed that occupational stress was a common risk factor for depressive symptoms (OR=3.29, 95%CI: 2.26, 4.79), anxiety symptoms (OR=2.87, 95%CI: 2.33, 3.53), and sleep disorder (OR=1.78, 95%CI: 1.46, 2.16). In addition, length of service and enterprise-scale were also risk factors for depressive symptoms, anxiety symptoms, and sleep disorders. In the 5−<10 and 10−<20 years of service groups, the risks of reporting depressive symptoms were 1.80 (95%CI: 1.18, 2.74) and 1.73 (95%CI: 1.10, 2.71) times higher than that of workers with less than 1 year of service, respectively; the risks of reporting anxiety symptoms were 1.98 (95%CI: 1.42, 2.76) and 2.11 (95%CI: 1.48, 3.01) times higher than that with less than 1 year of service, respectively; the risks of reporting sleep disorders were 1.58 (95%CI: 1.15, 2.16) and 1.78 (95%CI: 1.29, 2.45) times higher than that with less than 1 year of service, respectively. Workers in large enterprises were inclined to report more depressive symptoms, anxiety symptoms, and sleep disturbances than those in micro and small enterprises (OR=3.53, 95%CI: 2.41, 5.16; OR=2.49, 95%CI: 1.98, 3.13; OR=2.10, 95%CI: 1.67, 2.62). Conclusion The occupational stress level of mining industry workers in Gansu Province is high, and reporting occupational stress, 5−<10 and 10−<20 working age groups, and large enterprises are important risk factors affecting workers' mental health and sleep. It is necessary to increase the attention and develop intervention programs for mental health of miners in the working age group of 5−20 years old and in large enterprises.

ObjectiveTo develop a scale for evaluating the syndrome of internal retention of dampness and turbidity in nonalcoholic fatty liver disease （NAFLD） that combines disease and syndrome and has the characteristics of traditional Chinese medicine （TCM）. MethodsAn item pool was established for evaluating the syndrome of internal retention of dampness and turbidity in nonalcoholic fatty liver disease （NAFLD） with reference to the guideline for developing international scales. A clinical survey was conducted among the outpatients and inpatients who were diagnosed with NAFLD and had the syndrome of internal retention of dampness and turbidity in Department of Hepatology and Spleen-Stomach， The First Affiliated Hospital of Henan University of Chinese Medicine， from June to August， 2023， and the items were screened based on the classical test theory and the item response theory. An expert questionnaire was developed， and expert discussions were conducted using the Delphi method to identify the items for evaluating the syndrome of internal retention of dampness and turbidity in NAFLD. Finally， the scale was given scientific scores. ResultsA preliminary item pool was established， with 16 primary items and 22 secondary items， and it was divided into the two dimensions of disease and syndrome type. Clinical pre-survey suggested to retain 9 primary items and 14 secondary items， while the Delphi expert questionnaire recommended to retain 11 primary items and 15 secondary items， and tongue manifestation and pulse manifestation were no longer used for assessing the severity of syndrome. After hierarchical analysis and scientific assignment of scores， the scale for evaluating the syndrome of internal retention of dampness and turbidity in NAFLD had a total score of 123 points and 9 important items， i.e.， discomfort in the hypochondrium， abdominal fullness and distension， obesity， heaviness of the head and body， loose stool， anorexia， coughing up phlegm， nausea with a tendency to vomit， and lethargy. ConclusionA preliminary scale is established for evaluating the syndrome of internal retention of dampness and turbidity in NAFLD， which fills the gap in this research field and provides a basis for further clinical application.

ObjectiveTo investigate the mechanism by which 2，3，5，4'-tetrahydroxyldiphenylethylene-2-O-glucoside （THSG） mitigates cerebral ischemia/reperfusion （CI/R） injury by regulating mitochondrial calcium overload and promoting mitophagy. MethodsSixty male SD rats were randomized into sham， model， SAS （40 mg·kg^-1）， and low-， medium- and high-dose （10， 20， 40 mg·kg^-1， respectively） THSG groups， with 10 rats in each group. The middle cerebral artery occlusion/reperfusion （MCAO/R） model was established by the modified Longa suture method. An oxygen-glucose deprivation/reoxygenation （OGD/R） model was constructed in PC12 cells. Neurological deficits were assessed via Zea Longa scoring， and cerebral infarct volume was measured by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Structural and functional changes of cortical neurons in MCAO/R rats were assessed by hematoxylin-eosin and Nissl staining. PC12 cell viability was detected by cell counting kit-8 （CCK-8） assay， and mitochondrial calcium levels were quantified by Rhod-2 AM. Immunofluorescence was used to detect co-localization of PTEN-induced kinase 1 （PINK1） and leucine zipper/EF-hand-containing transmembrane protein 1 （LETM1） in neurons. Transmission electron microscopy （TEM） was employed to observe mitochondrial morphology in neurons. Western blot was employed to analyze the expression of translocase of outer mitochondrial membrane 20 （TOMM20）， autophagy-associated protein p62， microtubule-associated protein light chain 3 （LC3）， cysteinyl aspartate-specific proteinase-9 （Caspase-9）， B-cell lymphoma 2-associated protein X （Bax）， and cytochrome C （Cyt C）. ResultsCompared with the sham group， the model group exhibited increased infarct volume （P<0.01） and neurological deficit scores （P<0.01）， neuronal structure was disrupted with reduced Nissl bodies. （P<0.01）， mitochondrial swelling/fragmentation， decreased PINK1/LETM1 co-localization （P<0.01）， upregulated protein levels of LC3Ⅱ/LC3Ⅰ， TOMM20， Caspase-9， Bax， and Cyt C （P<0.01）， downregulated protein level of p62 （P<0.05）， weakened PC12 viability （P<0.01）， and elevated mitochondrial calcium level （P<0.01）. Compared with the model group， THSG and SAS groups showed reduced infarct volumes （P<0.05，P<0.01） and neurological deficit scores （P<0.05，P<0.01）， mitigated mitochondrial damage， and increased PINK1/LETM1 co-localization （P<0.01）. Medium/high-dose THSG and SAS alleviated the neurological damage， increased Nissl bodies （P<0.05，P<0.01）， downregulated the protein levels of p62， TOMM20， Caspase-9， Bax， and Cyt C （P<0.05，P<0.01）， and elevated the LC3Ⅱ/LC3Ⅰ level （P<0.05，P<0.01）. High-dose THSG enhanced PC12 cell viability （P<0.01）， increased PINK1/LETM1 co-localization （P<0.01）， and reduced mitochondrial calcium （P<0.01）. ConclusionTHSG may exert the neuroprotective effect on CI/R injury by activating the PINK1-LETM1 signaling pathway， reducing the mitochondrial calcium overload， and promoting mitophagy.

ObjectiveTo investigate the mechanism by which 2，3，5，4'-tetrahydroxyldiphenylethylene-2-O-glucoside （THSG） mitigates cerebral ischemia/reperfusion （CI/R） injury by regulating mitochondrial calcium overload and promoting mitophagy. MethodsSixty male SD rats were randomized into sham， model， SAS （40 mg·kg^-1）， and low-， medium- and high-dose （10， 20， 40 mg·kg^-1， respectively） THSG groups， with 10 rats in each group. The middle cerebral artery occlusion/reperfusion （MCAO/R） model was established by the modified Longa suture method. An oxygen-glucose deprivation/reoxygenation （OGD/R） model was constructed in PC12 cells. Neurological deficits were assessed via Zea Longa scoring， and cerebral infarct volume was measured by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Structural and functional changes of cortical neurons in MCAO/R rats were assessed by hematoxylin-eosin and Nissl staining. PC12 cell viability was detected by cell counting kit-8 （CCK-8） assay， and mitochondrial calcium levels were quantified by Rhod-2 AM. Immunofluorescence was used to detect co-localization of PTEN-induced kinase 1 （PINK1） and leucine zipper/EF-hand-containing transmembrane protein 1 （LETM1） in neurons. Transmission electron microscopy （TEM） was employed to observe mitochondrial morphology in neurons. Western blot was employed to analyze the expression of translocase of outer mitochondrial membrane 20 （TOMM20）， autophagy-associated protein p62， microtubule-associated protein light chain 3 （LC3）， cysteinyl aspartate-specific proteinase-9 （Caspase-9）， B-cell lymphoma 2-associated protein X （Bax）， and cytochrome C （Cyt C）. ResultsCompared with the sham group， the model group exhibited increased infarct volume （P<0.01） and neurological deficit scores （P<0.01）， neuronal structure was disrupted with reduced Nissl bodies. （P<0.01）， mitochondrial swelling/fragmentation， decreased PINK1/LETM1 co-localization （P<0.01）， upregulated protein levels of LC3Ⅱ/LC3Ⅰ， TOMM20， Caspase-9， Bax， and Cyt C （P<0.01）， downregulated protein level of p62 （P<0.05）， weakened PC12 viability （P<0.01）， and elevated mitochondrial calcium level （P<0.01）. Compared with the model group， THSG and SAS groups showed reduced infarct volumes （P<0.05，P<0.01） and neurological deficit scores （P<0.05，P<0.01）， mitigated mitochondrial damage， and increased PINK1/LETM1 co-localization （P<0.01）. Medium/high-dose THSG and SAS alleviated the neurological damage， increased Nissl bodies （P<0.05，P<0.01）， downregulated the protein levels of p62， TOMM20， Caspase-9， Bax， and Cyt C （P<0.05，P<0.01）， and elevated the LC3Ⅱ/LC3Ⅰ level （P<0.05，P<0.01）. High-dose THSG enhanced PC12 cell viability （P<0.01）， increased PINK1/LETM1 co-localization （P<0.01）， and reduced mitochondrial calcium （P<0.01）. ConclusionTHSG may exert the neuroprotective effect on CI/R injury by activating the PINK1-LETM1 signaling pathway， reducing the mitochondrial calcium overload， and promoting mitophagy.

Energy metabolism reconstruction is the new target of the treatment of heart failure. By combing the researches of Chinese medicinals for energy metabolism reconstruction of heart failure， it was found that Chinese medicinal compound formula and single Chinese medicinal have a certain role in regulating energy metabolism， mainly through three aspects， including the optimization of substrate utilization， improvement of mitochondrial structure， function， and homeostasis， and improvement of mitochondrial energy transport， so as to make the energy metabolism of the cardiomyocyte adjusted in the direction of beneficial to the organism， increasing the supply of energy， and improving the cardiac function.

ObjectiveBola-like short peptides exhibit novel self-assembly properties due to the formation of peptide dimers via hydrogen bonding interactions between their C-terminals. In this configuration, hydrophilic amino acids are distributed at both terminals, making these peptides behave similarly to Bola peptides. The electrostatic repulsive interactions arising from the hydrophilic amino acids at each terminal can be neutralized, thereby greatly promoting the lateral association of β-sheets. Consequently, assemblies with significantly larger widths are typically the dominant nanostructures for Bola-like peptides. To investigate the effect of hydrophilic amino acids on the self-assembly behavior of Bola-like peptides, the peptides Ac-RI₃-CONH₂ and Ac-HI₃-CONH₂ were designed and synthesized using the Bola-like peptide Ac-KI₃-CONH₂ as a template. Their self-assembly behavior was systematically examined. MethodsAtomic force microscopy (AFM) and transmission electron microscopy (TEM) were employed to characterize the morphology and size of the assemblies. The secondary structures of the assemblies were analyzed using circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy. Small-angle neutron scattering (SANS) was used to obtain detailed structural information at a short-length scale. Based on these experimental results, the effects of hydrophilic amino acids on the self-assembly behavior of Bola-like short peptides were systematically analyzed, and the underlying formation mechanism was explored. ResultsThe aggregation process primarily involved three steps. First, peptide dimers were formed through hydrogen bonding interactions between their C-terminals. Within these dimers, the hydrophilic amino acids K, R, and H were positioned at both terminals, enabling the peptides to self-assemble in a manner similar to Bola peptides. Next, β-sheets were formed via hydrogen bonding interactions along the peptide backbone. Finally, self-assemblies were generated through the lateral association of β-sheets. The results demonstrated that both Ac-KI₃-CONH₂ and Ac-RI₃-CONH₂ could self-assemble into double-layer nanotubes with diameters of approximately 200 nm. These nanotubes were formed by the edge fusion of helical ribbons, which initially emerged from twisted ribbons. Notably, the primary assemblies of these peptides exhibited opposite chirality: nanofibers formed by Ac-KI₃-CONH₂ displayed left-handed chirality, whereas those formed by Ac-RI₃-CONH₂ exhibited right-handed chirality. This reversal in torsional direction was primarily attributed to the different abilities of K and R to form hydrogen bonds with water. In contrast, Ac-HI₃-CONH₂ formed narrower twisted ribbons with a significantly reduced width of approximately 30 nm, which was attributed to the strong steric hindrance caused by the imidazole rings. The multilayer height of these ribbons was mainly due to the unique structure of the imidazole rings, which can function as both hydrogen bond donors and acceptors, thereby promoting aggregate growth in the vertical direction. ConclusionThe final morphology of the self-assemblies resulted from a delicate balance of various non-covalent interactions. By altering the types of hydrophilic amino acid residues in Bola-like short peptides, the relative strength of non-covalent interactions that drive assembly formation can be effectively regulated, allowing precise control over the morphology and chirality of the assemblies. This study provides a simple and effective approach for constructing diverse self-assemblies and lays a theoretical foundation for the development of functional biomaterials.