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.

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.

Objective To investigate the effect of cordyceps sinensis(CS)on the activation of fibroblasts through IL-6 trans-signaling pathway and its specific mechanism in the treatment of renal fibrosis.Methods Renal fibrosis mouse model was established by unilateral ischemia/reperfusion(UIR),and the mice were administered intragastrically CS,soluble glycoprotein 130 Fc(sgp130Fc)or Hyper-IL-6.Masson's trichrome staining was utilized to identify tubulointerstitial fibrosis.PAS staining was utilized to assess the extent of renal injury.Western blot was employed to analyze the expression levels of fibrosis markers[alpha-smooth muscle actin(α-SMA),fibronectin(FN)]and proteins associated with IL-6 trans-signaling pathway[phosphorylated signal transducer and activator of transcription 3(p-STAT3),soluble interleukin-6 receptor(sIL-6R)].The expression and localization of proteins were additionally detected by immunohistochemistry,immunofluorescence and qPCR.The effect of cordyceps sinensis extract cordycepin on IL-6 trans-signaling in fibroblasts was further investigated in vitro.Results The results from in vivo experiments showed that administration of CS during the chronic phase demonstrated a beneficial protective impact on inflammation and fibrosis in the affected kidney,and serum creatinine levels and collagen deposition were decreased.Western blot analysis revealed a decrease in the expression levels of α-SMA,FN,as well as IL-6 trans-signaling pathway protein p-STAT3,sIL-6R in the treatment group.Additionally,the mRNA expression levels of chemokines monocyte chemoattractant protein-1(MCP-1)and C-X-C motif chemokine ligand 12(CXCL12)were also decreased in the CS treatment group.Additionally,Hyper-IL-6 can partially counteract the therapeutic effects of CS.In vitro experiments further demonstrated that cordycepin inhibited the secretion of IL-6 from NRK-52E.Combined treatment of recombinant IL-6 and sIL-6R protein activated NRK-49F,leading to a significant increase in α-SMA,FN,and p-STAT3 expression levels.Cordycepin or sgp130Fc treatment significantly inhibited the proliferation of fibroblasts induced by IL-6 trans-signaling pathway.Conclusion CS can significantly reduce IL-6 secretion by renal tubular epithelial cells and inhibit the activation of IL-6 trans-signaling pathway in fibroblasts,thereby ameliorating renal interstitial fibrosis.

Objective:To investigate the protective effect of achyranthes bidentata(AB)on sperm quality in mice with sper-matogenic disorder through the glycolytic metabolic pathway and its action mechanism.Methods:We equally randomized 40 Kun-ming mice into a normal control,a model control,a low-dose AB(3.5 g/kg)and a high-dose AB group(7.0 g/kg),and established the model of spermatogenic disorder in the latter three groups of mice by intraperitoneal injection of doxorubicin(30 mg/kg).Two days after modeling,we collected the testis and kidney tissues and blood samples from the mice for observation of the pathological changes in the testis tissue by HE staining,detection of perm motility with the sperm quality analyzer,examination of the apoptosis of testis cells by flow cytometry,measurement of the levels of testosterone(T),malondialdehyde(MDA),superoxide dismutase(SOD)and cata-lase(CAT)in the serum and testis tissue by ELISA,and determination of expressions of the key enzymes of glycolysis hexokinase Ⅱ(HK2),pyruvate kinase M2(PKM2),platelet phosphofructokinase(PFKP),lactate dehydrogenase A(LDHA)and the meiosis pro-teins REC8 and SCP3 by Western blot,and the mRNA expressions of glycolytic phosphofructokinase 1(PFK1),phosphoglycerate ki-nase 1(PGK1),tumor necrosis factor-α(TNF-α)and interleukin-1 β(IL-1β)by fluorescence quantitative PCR(FQ-PCR).Results:Compared with the model controls,the mice in the AB groups showed significant increases in the testis coefficient,kidney in-dex,sperm concentration,sperm motility,spermatogonia,primary spermatocytes,spermatids,sperm count and the serum T level(P＜0.05 orP＜0.01),but dramatic decreases in the apoptosis of testis cells and percentage of morphologically abnormal sperm(P＜0.01).Achyranthes bidentata also significantly elevated the levels of SOD and CAT,and down-regulated the mRNA expressions of MDA,TNF-α and IL-1β(P＜0.05 or P＜0.01),and up-regulated the protein expressions of HK2,PKM2,PFKP,LDHA,REC8 and SCP3,and expressions of the glycolysis key genes Pfk1 and Pgk1(P＜0.05 orP＜0.01).Conclusion:Achyranthes bidentata ameliorates doxorubicin-induced spermatogenic disorder in mice by regulating the glycolytic pathway and reducing oxidative stress and the expressions of inflammatory factors.

Objective:To explore the application effect of BOPPPS teaching model in the teaching of Food Safety Supervision and Management course.Methods:Students of two parallel classes majoring in the Food Quality and Safety of the same grade of a university in Liaoning Province were selected,and the traditional teaching model and BOPPPS teaching model were used for teaching practice respectively.The scores,teaching effect and satisfaction of two groups were compared.Results:The regular performance and total scores of the experimental group were significantly higher than those of the control group(P＜0.05).In terms of enhancing students'interest in food safety supervision,improving knowledge and skills,cultivating self-directed learning and teamwork abilities,strengthening the close connection between the course and real cases,and providing assistance for future career,the experimental group performed significantly better than the control group(P＜0.05).Moreover,the satisfaction of the experimental group was higher than that of the control group(P＜0.05).Conclusion:BOPPPS teaching model has a remarkable effect in the teaching of Food Safety Supervision and Management course,providing an effective approach for the teaching reform of this course.

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.