Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Objective To understand the current situation of healthcare-associated infection(HAI)in China,pro-vide data support and decision-making basis for formulating scientific and effective strategies for HAI prevention and control.Methods A nationwide cross-sectional survey on HAI was conducted among various types and levels of medical institutions in China according to a unified protocol of bedside surveys and case investigations.Results In 2024,a total of 5 736 medical institutions and 2 751 765 patients were surveyed.Among them,34 889 HAI cases were identified,with a prevalence rate of 1.27％.The number of HAI episodes was 38 032,and case prevalence rate was 1.38％.The prevalence rate of HAI in medical institutions in different regions of China ranged from 0.66％to 2.35％.Among medical institutions of different scales,those with a bed capacity of ≥900 had the high-est incidence of HAI,reaching 1.65％.The most common infection site was the lower respiratory tract(44.66％),followed by the urinary tract(12.94％),surgical site(9.32％),upper respiratory tract(7.02％),and bloodstream infection(5.78％).The top 3 departments with the highest HAI rates were the general intensive care unit(10.02％),department of neurosurgery(5.51％),and department(group)of hematology(5.34％).A total of 23 238 strains of HAI pathogens were detected,with 10 714 strains(46.10％)from lower respiratory tract speci-mens.The top 5 detected strains were Klebsiella pneumoniae(14.76％),Pseudomonas aeruginosa(13.33％),Escherichia coli(12.79％),Acinetobacter baumannii(9.23％),and Staphylococcus aureus(7.88％).231 944 pa-tients underwent class Ⅰ incision surgery were monitored,with 1 647 cases experienced surgical site infection,and the prevalence rate of surgical site infection was 0.71％.The number of patients who should undergo pathogen de-tection(patients receiving therapeutic and therapeutic combined prophylactic antimicrobial agents)was 715 179,while the actual number was 480 492,with a pathogen detection rate of 67.18％.425 225 patients received patho-genic detection before treatment,with a detection rate of 59.46％.Conclusion The overall HAI prevalence in Chi-na is lower,showing disparities among medical institutions of different regions and scales.Therefore,precise imple-mentation of measures is necessary for HAI prevention and control,with a focus on high-risk institutions and high-risk departments,key areas,and critical procedures.All levels of medical institutions should continuously reduce the incidence of HAI by strengthening monitoring,standardizing the use of antimicrobial agents,and reinforcing basic HAI prevention and control measures.

Objective:To analyze the predictive role of WT1 expression levels pre-and early post-transplantation on relapse and overall survival(OS)in patients with acute myeloid leukemia(AML)undergoing allogeneic hematopoietic stem cell transplantation(allo-HSCT)during their first complete remission(CR1).Methods:A retrospective analysis was conducted on the clinical data of 107 adult AML patients who underwent allo-HSCT during their CR1 at our center between May 2012 and December 2021.The predictive role of bone marrow WT1 expression levels before transplantation and at 3 and 6 months post-transplantation on relapse and OS was explored in combination with relevant clinical factors.Results:The median follow-up time for the 107 patients was 70(range:11-117)months.Among the patients,15 cases died.Kaplan-Meier survial analysis showed that the 3-year overall survival(OS)rate was 85.0％.20 patients experienced relapse,with a median time to relapse of 8(range:0.5-44)months and a l-year cumulative relapse rate of 13.1％.The overall median value of WT1 before transplantation,3 months after transplantation,and 6 months after transplantation was 0.26％(range:0％-23.64％),with an upper quartile value of 0.74％.No statistically significant differences in WT1 expression levels were observed among the pre-transplantation,3-month post-transplantation,and 6-month post-transplantation time points(P=0.227).Univariate analysis showed that patients with WT1 levels＞0.74％at 3 months post-transplantation had a higher 1-year relapse rate(P=0.029)and lower 3-year OS rate(P＜0.001)compared to patients with WT1 levels ≤0.74％.Other significant factors affecting 1-year relapse included stem cell source(P=0.041)and chronic graft-versus-host disease(cGVHD)(P=0.013).For 3-year OS,additional influencing factors were genetic high risk(P=0.048)and stem cell source(P=0.016).Multivariate analysis revealed that WT1 level＞0.74％at 3 months post-transplantation had a trend to affect 1-year relapse rate(HR=3.309,95％CI:0.958-11.431,P=0.058),while the absence of cGVHD was an independent risk factor for 1-year relapse(HR=3.473,95％CI:0.749-16.100,P=0.037).Only WT1 level＞0.74％at 3 months post-transplantation was an independent risk factor for 3-year OS(HR=6.886,95％CI:2.402-19.738,P＜0.001).Conclusion:High WT1 expression level at 3 months post-transplantation in AML patients undergoing allo-HSCT during CR1 affects the 1-year relapse rate and 3-year OS,and is an independent risk factor affecting 3-year OS.These findings suggest that dynamic monitoring of WT1 expression levels has certain value in prognostic assessment of AML patients who received allo-HSCT during CR1.

OBJECTIVE To investigate the clinical distribution and dynamic change of drug resistance of K.pneu-moniae and carbapenem-resistant Klebsiella pneumoniae(CRKP)isolated from a three-A hospital of Suzhou so as to provide scientific bases for prevention and control of hospital-associated infections and reasonable application of antibiotics.METHODS The K.pneumoniae and CRKP strains that were isolated from the submitted specimens were collected from the patients who treated in the Affiliated Suzhou Hospital of Nanjing Medical University from 2019 to 2023.The clinical characteristics of the patients with infection and the trend of drug resistance were statis-tically analyzed.RESULTS Totally 5631 strains of K.pneumoniae were isolated,1205(21.40％)of which were CRKP,and the isolation rate of CRKP showed an upward trend in the five years(x2=236.352,P＜0.001).Among the K.pneumoniae isolates,51.59％were isolated from sputum,13.51％from urine;19.43％were isolated from intensive care unit(ICU),7.64％from emergency department,and 7.19％from respiratory department.There were significant differences in gender,age and season between the patients detected with CRKP and the patients detected with non-CRKP(P＜0.05).The drug resistance rates of the K.pneumoniae strains to cephalosporins,quinolones and carbapenems con-tinuously increased from 2019 to 2023(P＜0.001),the drug resistance rate to imipenem increased from 11.69％to 34.24％,meropenem from 10.92％to 34.24％.CONCLUSIONS The K.pneumoniae isolates show severe drug re-sistance from 2019 to 2023,and the isolation rate of CRKP strains rises increasingly.It is necessary for the hospi-tal to focus on the continuous monitoring of key populations and departments and optimize the management of an-tibiotics and infection control strategies so as to provide guidance for reasonable clinical use of antibiotics,effective control of transmission of drug-resistant strains and cope with the increasingly severe drug resistance.

Objective:To investigate the relationship between Ig class switch recombination(CSR)and mismatch repair(MMR)protein,microsatellite phenotype in extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue(MALT lymphoma).Methods:Forty cases of MALT lymphoma archived in the Department of Pathology,Jiading District Central Hospital,Shanghai University of Medicine & Health Sciences were selected as the observation group,and twenty cases of benign lymphoid tissue hyperplasia were as the control group.The expressions of IgG,IgM,IgD,and IgA in both groups were detected by immunohistochemical double staining,and MMR proteins including MLH1,MSH2,MSH6,and PMS2 in both groups were detected by immunohistochemistry.Multiplex fluorescence PCR capillary electrophoresis was used to detect microsatellite phenotype in tumor and adjacent tissues of the experimental group.Results:In the observation group,the proportions of single Ig heavy chain expression(mode Ⅰ),negative expression(mode Ⅱ),and multiple expression(mode Ⅲ)were 65％(26/40),27.5％(11/40),and 7.5％(3/40),respectively,while in the control group were 0(0/20),5％(1/20),and 95％(19/20).The proportion of Ig heavy chain expression mode Ⅰ+Ⅱ in the observation group was 92.5％,which was significantly higher than 5％in the control group(P＜0.0 1).In the observation group,partial deletion of MMR protein was observed in 3 cases(7.5％),including 2 cases of MSH6 deletion and 1 case of both MSH6 and PMS2 deletion.In the control group,there was 1 case(5％)with PMS2 deletion.There was no significant difference in the deletion rate of MMR protein between the two groups(P＞0.05).A total of 5 cases of microsatellite instability(MSI)were detected in the observation group,including 1 case of low-frequency MSI(MSI-L),4 cases of high-frequency MSI(MSI-H),and 2 cases of MSI-H with MSH6 deletion.When the loss expression of MSI-H or MMR protein was counted as a positive result,the MSI-H rate detected by PCR capillary electrophoresis was 10％(4/40),which was slightly higher than the MMR protein deletion rate detected by immunohistochemistry(7.5％,3/40),but there was no statistically significant difference between the two groups(P＞0.05).The MMR protein deletion rates among the Ig heavy chain protein expression mode Ⅰ,mode Ⅱ,and mode Ⅲ groups were 0(0/26),18.2％(2/11),and 33.3％(1/3),respectively.There was a statistically significant difference in the constituent ratios among the three groups(P＜0.05).The MMR protein deletion rates among the MSS,MSI-L,and MSI-H groups were 2.9％(1/35),0(0/1),and 50％(2/4),respectively.There was a statistically significant difference in the constituent ratios among the three groups(P＜0.05).MMR protein deficiency was positively correlated with Ig heavy chain expression pattern and MSI(r=0.41,P＜0.05;r=0.48,P＜0.05),but Ig heavy chain expression pattern was not correlated with MSI(r=0.02,P＞0.05).Conclusion:Ig heavy chain CSR detection is helpful for the differential diagnosis of MALT lymphoma.Low frequency MMR protein deletion and MSI-H phenotype exist in MALT lymphoma,which may be of certain value for the study of its occurrence,development and clinical treatment.

Persistent atrial fibrillation and other factors can cause mitral and tricuspid annular dilation and leaflet regurgitation,leading to severe functional mitral and tricuspid regurgitation.Patients often experience significant heart failure symptoms and poor prognosis.For patients with severe mitral or tricuspid regurgitation who are at high risk or contraindicated for surgical procedures,transbronchial repair(TEER)is an important alternative therapy that can effectively reduce valve regurgitation and improve cardiac function;Although there is a lack of large-scale data on atrial functional reflux,existing experience still shows that TEER can significantly reduce reflux and improve patients'quality of life.However,double valve intervention therapy poses challenges,especially when combined with TEER repair,which is technically more complex,time-consuming,and carries higher risks.Foreign data shows that simultaneous or staged double valve intervention can safely improve cardiac function and increase survival rates,but the optimal intervention strategy still needs further research.Due to the fact that tricuspid TEER devices have not yet been launched in China,only staged treatment can be adopted at present.This case report shows a patient with severe atrial functional mitral and tricuspid regurgitation who underwent staged transcatheter edge to edge repair surgery successfully.During a 1-year follow-up,bilateral valve regurgitation continued to improve,indicating that staged repair of bilateral atrioventricular valve regurgitation through the catheter margin is a feasible and effective treatment option.

A mounting body of research suggests that circRNAs significantly contribute to the develop-ment of myocardial fibrosis.The microarray results of human circular RNA expression profile indicated that circHERC4_041 expression increased in the myocardium of patients with heart failure,RT-qPCR a-nalysis confirmed that the myocardial expression level of circHERC4_041 in individuals with heart failure were considerably elevated compared to that in healthy organ donors.Fluorescence in situ hybridization(FISH)confirmed that circHERC4_041 was abundant in the cytoplasm of human cardiomyocyte AC16.Overexpression of circHERC4_041 in mouse myocardial fibroblasts(mCFs)mediated by adenovirus in-hibited the expression of fibrosis-related proteins in mCFs.Experiments involving cell proliferation,wound healing,and Transwell assays demonstrated that overexpression of circHERC4_041 suppressed the growth and mobility of mCFs(P＜0.001).Sequence analysis results suggested that circHERC4_041 con-tains potential ribosome entry sequence(IRES)and open reading frame(ORF).Western blot confirmed that circHERC4_041 could translate the 516 amino acid HERC4-516aa protein,which was mainly located in the cytoplasm of the cell.Cell functional experiments confirmed that circHERC4_041 inhibited the fi-brotic phenotype of mCFs by specifically translating HERC4-516aa(P＜0.05).The specific interaction between HERC4-516aa and transglutaminase 2(TGM2)was confirmed by IP-MS screening and Co-IP i-dentification.Further results found that the degradation of TGM2 was promoted through proteasome path-way.The overexpression of TGM2 in mCFs facilitated by adenoviral vectors could counteract the suppres-sive effects of HERC4-516aa on the fibrotic phenotype of mCFs.Therefore,this study confirmed that the HERC4-516aa protein translated by circHERC4_041 can specifically bind to TGM2 to inhibit the fibrotic phenotype of myocardial fibroblasts.

Objective To explore the relationship between community health follow-up management and the mental health of the long-term care insurance residents,and to provide a basis for the construction of an integrated community home care service mode for disabled elders.Methods The residents were selected through cluster sampling who participated in LTCI home care from Jan 1 to Dec 31,2021.After a year of participation,the subjects'mental health was assessed face-to-face by trained community doctors using the Self-Rating Anxiety Scale and the Self-Rating Depression Scale.By referring to residents'electronic health records combined with on-site questionnaire survey,community doctors collected the demographic information and health follow-up management provided by primary medical and health institutions.The multivariate logistic regression were conducted to evaluate the association between follow-up care and mental health outcomes.Results The study consisted of 399 LTCI-enrolled individuals,57.64%(n=230)received follow-up care by family physicians.The prevalence of anxiety and depression among participants was 19.80%(n=79)and 67.67%(n=270),respectively.Univariate analysis found that community health follow-up management could underscore the potential impact of follow-up care in mitigating anxiety(χ2=38.926,P<0.001)and depression(χ2=14.598,P<0.001)among LTCI enrollees.Multivariate analysis revealed that follow-up care was an independent protective factor against anxiety(adjusted OR=0.351,95%CI:0.176-0.701,P=0.003).However,follow-up care did not significantly impact depression prevalence.Additionally,LTCI grade and education level were also identified factors influencing the mental health of participants(P<0.05).Conclusion Community health service centers provide health follow-up management that plays a positive role in alleviating the anxiety symptoms of disabled residents under long-term care insurance home care.It is an effective way to improve the quality of LTCI home care services.

Objective To develop a novel type of transparent simulation manikin as a surgical training model to meet the surgical treatment demand on the medical train.Methods A transparent manikin was developed with the steps of basic data collection,motherboard design and manufacture and module production and assembly.Firstly,basic data collection was carried out with reference to standardized human anatomy and parameters.Secondly,some software such as UG NX7.5 was used to construct the motherboard of the manikin.Finally,module production and assembly were performed with the materials of acrylic,transparent rubber,silicone and hydrogel and the technology of silicone infusion.Results The transparent manikin developed had its anatomy structure close to that of the real body and high visuality for its internal and external components,which simulated a variety of war wounds and thus could be integrated with the surgical training scenarios on the medical train effectively.Conclusion The transparent manikin developed is characterized by high visuality,modularity and blood flow,and meets the demands for surgical training on the medical train.[Chinese Medical Equipment Journal,2025,46(6):111-115]