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 explore the behavioral patterns and hippocampal neurogenesis of CHD8+mice,and to provide behavioral and morphological basis for improving autism like behavior and neurogenesis.Methods Genotype of wild type(WT)and CHD8+/-mice was identified.Weight measurement was conducted on both male and female mice of the WT and CHD8+/-strains.Subsequently,a battery of behavioral tests was administered,which included three-chamber test,self-grooming test,nesting test,Y-maze spontaneous alternation test,food burial test,open-field test and light-dark transition test.Afterwards,the mice were administered 2％pentobarbital sodium(2 ml/kg)to induce anesthesia.Their brains were frozen with 4％paraformaldehyde,removed for photography and analysis to identify any alterations in brain size.Western blotting and immunofluorescent labeling were used to detect changes in the process of hippocampus neurogenesis.Results Western blotting analysis demonstrated a decrease in the amounts of chromodomain helicase DNA binding protein 8(CHD8)protein in both male and female mice with CHD8+genotype,as compared to WT mice.There were no notable disparities in body weight between male and female WT and CHD8+mice,as well as in brain size.The three-chamber social behavior test revealed that both male and female CHD8+/-mice had social deficiencies(P＜0.05).During the open field test,there was no significant difference in the total distance moved by male and female WT and CHD8+/-mice.However,the amount of time spent in the central region was considerably lower in CHD8+/-mice compared to the WT mice(P＜0.01).Furthermore,the light-dark transition test revealed that both male and female CHD8+/-mice spent considerably less time investigating the white box compared to the WT mice(P＜0.05).Nevertheless,there were no notable alterations found in self-grooming,nesting,spontaneous alternation of Y-maze,and food burial experiments.In addition,Western blotting result demonstrated a significant drop in doublecortin(DCX)expression(P＜0.001),and immunofluorescent staining revealed a notable reduction in the number of DCX+cells(P＜0.01)in the hippocampus of CHD8+/-mice.Conclusion CHD8+/-mice exhibit social disorders and anxiety-like behaviors,with a decrease in the number of newly generated neurons in the hippocampus and neurogenesis disorders.

Objective:To describe the prevalence of preserved ratio impaired spirometry (PRISm) in participants from the China Kadoorie Biobank (CKB) and explore the influencing factors.Methods:The CKB project conducted the baseline survey, the first and the second resurvey in 2004-2008, 2008, and 2013-2014, respectively. Based on the lung function tests, the participants were categorized into three groups: regular, PRISm, and airflow obstruction. The prevalence of PRISm was reported by gender, age, and region at the baseline survey. The secular trend in the prevalence of PRISm was described during the three surveys. Finally, we used the multiple logistic regression model to examine the factors related to PRISm in the baseline survey.Results:After standardization for gender, age, and region according to the sixth national census data in 2010, the overall prevalence of PRISm and airflow obstruction among the 434 760 participants at baseline was 24.8% and 6.1%, respectively. The prevalence of PRISm was higher in rural (25.4%) than that in urban areas (24.3%). Of the 10 study regions, Gansu had the highest prevalence of PRISm (56.0%), while Henan had the lowest (15.4%). After standardization for gender, age, and region according to the baseline population, the prevalence of PRISm decreased from 24.9% at baseline to 15.7% in the second resurvey, and the prevalence of airflow obstruction increased from 5.9% to 21.4%. Unmarried status, current smoking, using solid fuels for cooking, low body weight, being overweight, obesity, and central obesity were associated with an increased risk of PRISm. In contrast, higher education attainments, increased household income, and maintaining a specific degree of physical activity were associated with a reduced risk of PRISm.Conclusions:The prevalence of PRISm was high in adults aged 40 years and above in China, and it varied by sociodemographic and lifestyle factors.

Objective:To explore the impacts of smoking on the need for respiratory support and mortality in patients hospitalized with pneumonia.Methods:A total of 24 367 patients hospitalized with pneumonia from 2009 to 2017 in the China Kadoorie Biobank, were included. Smoking status was self-reported, and data regarding respiratory support during hospitalization and mortality during follow-up were obtained from medical claims and death registries, respectively. OR, HR, and 95% CI were calculated and adjusted for potential confounders using logistic regression models and Cox proportional hazards regression models, respectively. Results:Among males, current smokers or those who quit smoking due to illness had higher risks of requiring respiratory support ( OR=1.15, 95% CI: 1.03-1.29), 1-year mortality ( HR=1.66, 95% CI: 1.32-2.08), and 5-year mortality ( HR=1.32, 95% CI: 1.13-1.54) following pneumonia hospitalization compared to nonsmokers. Male smokers who started smoking at a younger age or with longer smoking duration had the highest mortality risks (trend test both P<0.05). Female current smokers or those who quit smoking due to illness had higher risks of 1-year mortality ( HR=1.62, 95% CI: 1.17-2.23) and 5-year mortality ( HR=1.33, 95% CI: 1.06-1.67). We found no statistically significant difference in 90-day mortality between current smokers/those who quit smoking due to illness and nonsmokers. Conclusions:Smoking was associated with higher risks of requiring respiratory support and mortality in patients hospitalized with pneumonia, especially among males and heavy smokers. These findings highlight the need for targeted strategies to promote smoking cessation in patients hospitalized with pneumonia.

Objective:To explore the association between spicy food intake and the risk for cardio/cerebrovascular diseases.Methods:Data were collected from the China Kadoorie Biobank project conducted in Pengzhou, Sichuan Province. Using the Cox proportional hazards regression model, we analyzed the associations of the frequency of spicy food intake, spicy level, types of spicy food, and the age when regular intake of spicy food began (intake in 1 day/week), with the risk for cardio/cerebrovascular disease. Furthermore, the associations with the risks for ischemic heart disease (IHD) and cerebrovascular diseases, as well as the risk of ischemic stroke (IS) and hemorrhagic stroke (HS) were analyzed.Results:A total of 54 859 study participants were included in the study, in whom 49 320 had spicy food intake (89.90%). In these participants, 37 680 (68.69%) had spicy food intake in 6-7 days/week, 5 036 (9.18%) had spicy food intake in 1-5 days/week, and 6 604 (12.03%) had spicy food intake once a week; 5 539 (10.10%) had never/almost never had spicy food intake. After adjusting for multiple confounding factors, compared with those who never/almost never had spicy food intake, intake of spicy food was associated with reduced risks for IHD (intake in 6-7 days/week: HR=0.86, 95% CI: 0.78-0.95), cerebrovascular diseases (intake in 6-7 days/week: HR=0.88, 95% CI: 0.81-0.96), and IS (intak in 6-7 days/week: HR=0.85, 95% CI: 0.76-0.95). With the increase of spicy food intake frequency, the risk for cardio/cerebrovascular disease decreased (intake in 1-5 days/week: HR=0.91, 95% CI: 0.85-0.98; intake in 6-7 days/week: HR=0.89, 95% CI: 0.84-0.94) (trend test P<0.001). However, no statistical association was found between spicy food intake and the risk for HS. In terms of spicy level, after adjusting for multiple confounding factors, compared with those who never/almost never had spicy food intake, intake of spicy food was associated with reduced risk for cardio/cerebrovascular disease (moderate: HR=0.86, 95% CI: 0.82-0.90) and cerebrovascular disease (moderate: HR=0.90, 95% CI: 0.84-0.97). With the increase of spicy level, the risk for IHD decreased (moderate: HR=0.86, 95% CI: 0.79-0.93; strong: HR=0.84, 95% CI: 0.74-0.95) (trend test P<0.001). After adjusting for multiple confounding factors, compared with those who never/almost never had spicy food intake, intake of any type of spicy food was associated with reduced risk for cardio/cerebrovascular disease, IHD, and cerebrovascular disease. Regulat intake of spicy food from age 0-10 years was associated with reduced risk for cardio/cerebrovascular disease, IHD, and cerebrovascular disease. Regular intake of spicy food from age 11-20 years reduced the risk for cardio/cerebrovascular disease and IHD. There was no significant association between the regular intake of spicy food from age 21-79 years and the risks for cardio/cerebrovascular disease, IHD and cerebrovascular disease. Conclusion:The intake of spicy food could reduced the risk for cardio/cerebrovascular diseases, IHD, cerebrovascular diseases and IS in residents aged 30-79 years in Sichuan.

Objective:To investigate the effect of physical activity on mortality risk in patients with chronic obstructive pulmonary disease (COPD) in Sichuan Province.Methods:Based on baseline data from 2004 to 2008 from the China Kadoorie Biobank project site in Pengzhou City, Sichuan Province, a total of 8 501 COPD patients aged 30-79 years were enrolled and followed up for a long period to determine mortality outcomes. Quartiles were used to group physical activity levels. The Cox proportional hazards regression model was used to analyze the effect of physical activity level on mortality outcomes.Results:As of December 31, 2017, the cumulative follow-up of the participants totaled 85 600.58 person-years (mean follow-up duration: 10.07 years). During this period, a total of 2 000 deaths were recorded, yielding a cumulative mortality rate of 23.53%. Among these deaths, 665 were attributed to COPD, corresponding to a cumulative mortality rate of 7.82%; and 1 116 were attributed to cardiovascular and cerebrovascular disease (CVD), corresponding to a cumulative mortality rate of 13.13%. The Cox proportional hazards regression model analysis revealed that, after adjusting for confounding factors, total physical activity was associated with a reduced risk of mortality from COPD, CVD, and all causes in patients with COPD. Compared with the low-level group of total physical activity, the medium-high-level group had the lowest risk of COPD mortality, with an HR of 0.39 (95% CI: 0.30-0.49). The high-level group had the lowest risk of CVD death and all-cause death, with HRs of 0.46 (95% CI: 0.37-0.56) and 0.55 (95% CI: 0.48-0.64), respectively. The lowest risk of COPD death and CVD death was found in the medium-high level of work-based physical activity group, with HRs of 0.36 (95% CI: 0.28-0.46) and 0.43 (95% CI: 0.36-0.51), respectively; the risk of all-cause mortality was lowest in the medium-high and high-level groups, with HRs values of 0.53 (95% CI: 0.46-0.61) and 0.53 (95% CI: 0.45-0.61). The risk of COPD death was lowest in the high-level transportation physical activity group, with an HR of 0.66 (95% CI: 0.53-0.83), and the risk of CVD and all-cause death was lowest in the medium-high level group, with HRs of 0.63 (95% CI: 0.53-0.76) and 0.73 (95% CI: 0.64-0.84), respectively. The risk of COPD death and CVD death was the lowest in the high-level domestic physical activity group, with HRs of 0.66 (95% CI: 0.49-0.89) and 0.76 (95% CI: 0.61-0.95), respectively, and the risk of all-cause death was the lowest in the medium-high level group, with an HR of 0.82 (95% CI: 0.72-0.94). There is no statistical association between leisure physical activity and the risk of death from three types of diseases. Conclusions:Total physical activity, including work-based, transportation-based, and domestic physical activity, reduced the risk of COPD, CVD, and all-cause mortality in patients with COPD in Sichuan Province. The magnitude of mortality risk was influenced by the type and level of physical activity.

Objective To explore the application value of serum cystatin C(CysC)and cluster of differentiation 147(CD147)in predicting restenosis after intracranial artery stenosis stenting(ICASS)in patients with acute ischemic stroke(AIS).Methods A total of 151 AIS patients who received ICASS were selected as the study group,and 112 healthy individuals who underwent physical examinations during the same period were chosen as the control group.The study group was further divided into the restenosis group(30 cases)and the non-stenosis group(121 cases)based on the restenosis status within 6 months after ICASS.The serum CysC levels of the subjects were detected by immunoturbidimetry,and the serum CD147 levels were measured by enzyme-linked immunosorbent assay.Multivariate Logistic regression analysis was conducted to identify factors influencing restenosis after ICASS in AIS patients.The receiver operating characteristic(ROC)curve was used to evaluate the application efficacy of serum CysC and CD147 levels in predicting restenosis after ICASS in AIS patients.Results Serum levels of CysC and CD147 were higher in the study group than those in the control group(P＜0.01).The proportion of patients with stenosis degree>75%and serum levels of CysC and CD147 were higher in the restenosis group than those in the non-stenosis group(P＜0.01).The degree of stenosis>75%and the increased serum levels of CysC and CD147 were risk factors for restenosis after ICASS in AIS patients(P＜0.01).ROC curve analysis showed that serum CysC and CD147 levels independently predicted the AUC of AIS patients with restenosis after ICASS were 0.845 and 0.850,respectively,and the combined predicted AUC was 0.942.The combined prediction efficiency was significantly better than that of single indicator prediction(P＜0.05).Conclusion The increased levels of serum CysC and CD147 in AIS patients are risk factors for restenosis after ICASS,and the combination of the two is more effective in predicting intracranial artery restenosis after ICASS in AIS patients.

Objective:To explore the prospective association between physical activity level and mor-tality risk in Chinese adults with chronic obstructive pulmonary disease(COPD).Methods:Based on the China Kadoorie Biobank(CKB)who had COPD at the baseline survey,this study employed the Cox proportional hazards regression model to estimate the prospective associations between the overall physical activity,different intensities(low-level,moderate-to-vigorous-level),and types(occupational,non-occupational)of physical activity level and the risks of all-cause and cause-specific mortality,such as vascular diseases,cancer,and respiratory diseases.Based on the quintiles of physical activity level,par-ticipants were divided into five groups(Q1-Q5),with the lowest quintile group(Q1)as the reference group.Hazard ratio(HR)and 95％confidence interval(95％CI)were calculated for the remaining.In our study,we also performed sensitivity and subgroup analyses,including age,gender,self-rated health status,severity of COPD,etc.Results:Among 33 588 COPD patients at the baseline survey,8 314(22.2％)deaths were documented during an average follow-up of(11.1±3.1)years.Negative linear associations between the overall physical activity level and mortality risk from all-cause,vascular,and respiratory diseases were observed(P trend for linear correlation being＜0.001,0.002,＜0.001).Compared with the lowest quintile group of total physical activity(Q1),the hazard ratios(HR)and 95％confidence intervals(CI)for all-cause mortality,vascular disease mortality,and respiratory disease mortality in the highest quintile group(Q5)were 0.77(0.70,0.85),0.77(0.65,0.91),and 0.58(0.48,0.71),respectively.The low-level and moderate-to-vigorous-level physical activity were nega-tively associated with all-cause mortality in the COPD patients(P trend for linear correlation:0.002,＜0.001,respectively).Compared with the lowest quintile group of low-intensity and moderate-to-vigorous intensity physical activity(Q1),the HRs(95％CI)for all-cause mortality in the highest quintile group(Q5)were 0.89(0.82,0.97)and 0.79(0.72,0.87),respectively.The occupational and non-occupational physical activity were also found to have a linear inverse association with all-cause mortality risk among the COPD patients(P trend＜0.001 and 0.015,respectively).Compared with the lowest quintile group of occupational and non-occupational physical activity(Q1),the HR(95％CI)for all-cause mortality in the highest quintile group(Q5)were 0.69(0.61,0.78)and 0.91(0.84,0.98),respectively.The associations between overall physical activity and all-cause mortality risk were stronger for patients aged 60 and above,female,and who reported poor health status(P for interaction:0.028,0.012,0.010).The protective effect of total physical activity was also applicable to the COPD patients of varying severity.Conclusion:Physical activity could reduce the mortality risk in a dose-response relationship among COPD patients,regardless of its intensity and type,especially among indi-viduals aged 60 and above,females,and those with poor self-report health status.

This study was aimed at understanding the prevalence and drug resistance status of Salmonella of waterfowl ori-gin in the Guangdong region in the past decade,to guide prevention and control efforts.The drug-sensitive paper slide method was used to conduct drug susceptibility testing on 314 waterfowl-originating Salmonella strains isolated from 238 waterfowl farms in the Guangdong region from 2013 to 2023.The isolated Salmonella strains were most resistant to penicillin,amoxicil-lin,cefradine,and cefazolin in the β-lactam group;sulphadoxine dimethylpyrimidine in the sulphonamide group;and tetracy-cline in the tetracycline group.The resistance rates ranged from 73.57％to 89.49％.The highest sensitivity was observed to amikacin,gentamicin,and kanamycin in the aminoglycoside group,and norfloxacin in the quinolone group,with susceptibility rates all exceeding 50％.The 280 strains of Salmonella showed multi-drug resistance to six classes of antimicrobial drugs and high resistance(as much as 60.83％)to five drug classes.Correlation analysis revealed the highest correlations for florfenicol with gentamicin,and for amoxicillin with penicillin(r=0.650 for both),followed by gentamicin with kanamycin(r=0.620).Salmonella resistance in waterfowl in Guangdong Province was generally severe and showed a complex pattern of drug resist-ance.Detection of waterfowl pathogens should be strengthened to prevent the spread of drug-resistant bacteria and support ra-tional use of antibiotics.This work provides a reference for Salmonella prevention and control in waterfowl farms.