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.

Ethical utilitarianism is a consequence-oriented ethical theory that pursues the maximization of happiness and fully considers the long-term impact of behavior. In the ethical review of human organ donation and transplantation, this theory is mainly applied in three aspects, ethical review supervision, process and content. However, in practice, it faces challenges such as the difficulty and subjectivity of utility calculation, the balance between individual rights and social welfare, the long-term impact of decision-making, and international cooperation under a global perspective. Therefore, governance strategies such as improving ethical review policy rules, refining the ethical review system by drawing on international experience, and strengthening public education and publicity are proposed. Despite many challenges, ethical utilitarianism still provides an important theoretical framework for the ethical review of human organ donation and transplantation. Therefore, this article reviews the application of ethical utilitarianism in the ethical review of human organ donation and transplantation and its challenges, aiming to provide a reference for related research on the ethical review of human organ donation and transplantation.

Objective:To investigate teachers' evaluation and willingness and the influencing factors regarding the adoption of the flipped classroom teaching mode in undergraduate pediatrics education.Methods:From December 2022 to December 2024, a questionnaire survey was conducted among the teachers who were responsible for teaching Child Health and Disease（Pediatrics) to the eight-year clinical medicine students at Peking University Health Science Center. Their views, evaluation, and willingness of implementing the flipped classroom teaching mode were investigated. Logistic regression analysis was performed using SPSS 26.0 software to explore the factors influencing teachers' willingness to adopt the flipped classroom teaching mode.Results:A total of 102 questionnaires were collected. Among the teachers, 20.59%（ n=21) believed that the teaching effect of the flipped classroom was better than that of the traditional class, 58.82%（ n=60) considered its effectiveness comparable, and 20.59%（ n=21) found it less effective. The most influential factors affecting the effectiveness of flipped classroom were students' self-learning with online videos [(4.39±0.73) points], student participation in the flipped classrooms [(4.26±0.72) points], the adequacy of teachers' pre-class preparation [(4.18±0.65) points], and the suitability of the teaching content for the flipped classroom [(4.11±0.76) points]. Teachers believed that the flipped classroom significantly enhanced students' autonomous learning ability [(4.11±0.63) points], clinical thinking [(4.04±0.58) points], and expression skills [(3.80±0.61) points]. Additionally, 78.43%（ n=80) of the teachers expressed willingness to continue participating in flipped classroom teaching. Factors influencing teachers' willingness to adopt the flipped classroom included gender, satisfaction with students' classroom participation, and personal experience with the effectiveness of the flipped classroom（ P<0.05). Conclusions:The flipped classroom teaching mode is well-accepted by teachers. Students' classroom participation affects teachers' willingness to continue using the flipped classroom teaching mode. In the future, the content of flipped classroom should be arranged individually according to specific teaching objectives to increase students' classroom participation and promote the cultivation of students' ability.

Objective To analyze the clinical efficacy of"Siming Acupoint"massage technique in the treatment of true myopia in children and adolescents,and explore the related factors influencing the therapeutic effect.Methods From January 2021 to January 2024,257 cases of children and adolescents with true myopia and 475 eyes treated and followed up at the Pediatric Massage Center of Shandong Hospital of Traditional Chinese Medicine were included in this study.And they were divided into the low myopia group(374 eyes),the moderate myopia group(76 eyes)and the high myopia group(25 eyes).The clinical efficacy was analyzed by comparing the observation indicators changes before and after the intervention.The occurrence of ineffective treatment was observed,and the related factors of ineffective treatment were explored by using univariate comparison and multivariate Logistic regression analysis.Results Clinical results showed that the effective rate of 257 children and 475 eyes was 93.05%;the effective rate of 374 eyes in the low myopia group was 98.13%;the effective rate of 76 eyes in the moderate myopia group was 81.58%;the effective rate of 25 eyes in the high myopia group was 52.00%.The score of visual fatigue symptoms after the intervention was significantly lower than that before the intervention(P<0.001);The naked eye vision after the intervention was significantly higher than that before the intervention(P<0.001);After the intervention,NRA and PRA were significantly enhanced compared with those before the intervention(P all<0.001).Risk factor analysis of ineffectiveness showed that there were 33 eyes in the ineffective group and 442 eyes in the effective group.The proportion of patients with a history of sweet tooth in the ineffective group was significantly higher than that in the effective group(P=0.020);The course of disease in the ineffective group was significantly longer than that in the effective group(P=0.001);And there were also significant differences in the degree of myopia between the two groups,the proportion of high myopia in the ineffective group was significantly higher than that in the effective group(P<0.001);The spherical diopter,equivalent spherical diopter and cylindrical diopter in the ineffective group were all significantly higher than those in the effective group(P all<0.001);The axial length of the eye in the ineffective group was significantly longer than that in the effective group(P=0.005);The naked eye vision before treatment and the corrected naked eye vision at the first treatment in the ineffective group were both worse than those in the effective group(both P<0.001);The proportion of patients with outdoor activities<2 hours/day and the proportion of patients with night sleep time<7 hours/day in the ineffective group were significantly higher than those in the effective group(P=0.022,P=0.012).Binary multivariate Logistic regression analysis showed that combined outdoor activities<2 hours/day(OR=8.270,P<0.001),equivalent spherical diopter(OR=2.724,P=0.005),and night sleep time<7 hours/day(OR=2.507,P=0.014)were the risk factors for ineffective treatment of true myopia in children and adolescents with"Siming Acupoints"massage technique.The ROC curve showed that the area under the curve for outdoor activities<2 hours/day was 0.603;The area under the curve for equivalent spherical diopter was 0.678;the area under the curve for night sleep time<7 hours/day was 0.667.Conclusion The"Siming Acupoints"massage technique may be able to improve the naked eye vision of patients,improve NRA,PRA and visual fatigue symptoms,and control the growth of axial length and equivalent spherical diopter.Outdoor activities<2 hours/day,equivalent spherical diopter,and night sleep time<7 hours/day are the risk factors for ineffective treatment of true myopia in children and adolescents with"Siming Point"massage technique.

Aim To study the possibility of luteolin(LUT)as a new drug of traditional Chinese medicine and its improving effect on glucose and lipid metabo-lism and liver oxidative stress injury in db/db mice,and to explore the possible mechanism.Methods AI was used to predict the drug toxicity,evaluate the phys-ical and chemical properties and segment the molecular structure of LUT.Molecular docking was used to verify the binding ability of LUT with Nrf2 and HMOX1;db/m mice were divided into the group C,and db/db mice were randomly divided into the T,L,M,H and P groups.The body weight and FBG changes were ob-served within 12 weeks of intervention.The expres-sions of FBG,HbA1c,Fins,TC,TG,HDL-C,LDL-C were detected.The pathomorphological changes and steatosis of mouse liver were observed by HE and oil red O staining.The expression of MDA,SOD and GSH-Px in liver was detected by Kit.The protein and mRNA expressions of Nrf2 and HMOX1 were detected by immunohistochemistry,WB and qPCR.Results AI algorithm predicted the safety and easy synthesis of LUT.LUT intervention had no significant effect on the body weight of db/db mice.After 12 weeks,compared with the group C,the livers of mice in group T showed disordered structure of hepatic lobules,irregular ar-rangement of hepatocytes,and a large number of fat vacuoles and lipid droplets in the cytoplasm.Compared with the group T,LUT intervention could improve the pathological changes of liver,reduce the expression of FBG,HbA1c,fins,TC,TG,LDL-C,MDA,improve the level of HOMA-IR,and upregulate the activities of SOD and GSH-Px.Molecular docking results showed LUT had strong binding with Nrf2 and HMOX1,and could increase the expression of Nrf2 and HMOX1.Conclu-sion LUT can correct the disorder of glucose and lip-id metabolism in db/db mice,and improve the level of oxidative stress in liver of mice through Nrf2/HMOX1 pathway,which has the development prospect as a new Chinese medicine for the treatment of T2DM.

Objective To analyze the epidemiological characteristics of acute respiratory infections(ARIs)during the autumn-winter season in Beijing,providing evidence for the prevention,control,diagnosis,and treatment of ARIs.Methods A convenience sampling method was employed,enrolling patients who visited Peking Union Medical College Hospital(PUMCH)between September 2023 and February 2024 due to ARIs.Na-sopharyngeal swabs were collected,and real-time fluorescence quantitative PCR was used to detect six common respiratory pathogens[influenza A virus(FluA),influenza B virus(FluB),human rhinovirus(HRV),Myco-plasma pneumoniae(MP),respiratory syncytial virus(RSV),and adenovirus(ADV)],as well as SARS-CoV-2 infection.The distribution patterns of pathogen infections were analyzed.Results A total of 5556 eligible patients were included.The overall positivity rate for the six common respiratory pathogens was 63.7％,with sin-gle-pathogen positivity at 54.0％,dual-pathogen positivity at 8.9％,and triple or more pathogen positivity at 0.7％.The predominant pathogens detected were FluA(16.1％)and RSV(15.7％),followed by ADV(11.1％),MP(11.1％),HRV(10.0％),and FluB(10.0％).No significant difference in overall pathogen positivity was observed between genders.However,significant differences were found between autumn and winter(x2=34.617,P＜0.001)and among pediatric,young/middle-aged,and elderly patients(x2=422.38,P＜0.001).Specifically,MP(x2=8.647,P=0.003),FluA(x2=131.932,P＜0.001),and HRV(x2=174.199,P＜0.001)exhibited significantly higher positivity rates in autumn than in winter,whereas FluB was more prevalent in winter(x2=287.894,P＜0.001).In pediatric patients,MP,RSV,HRV,and ADV positivity rates were significantly higher than in young/middle-aged and elderly patients(all P＜0.001),whereas FluB was more common in young/middle-aged patients(both P＜0.001).The positivity rates of the six common respiratory pathogens significantly declined during the SARS-CoV-2 epidemic period,exhibiting an asynchronous seasonal pattern.Conclusions The prevalence of respiratory pathogens in Beijing is associated with age and season.Tar-geted preventive measures should be implemented in different seasons and for key populations.

OBJECTIVE: To explore the clinical and genetic characteristics of five fetuses with Harlequin ichthyosis (HI). METHODS: Five fetuses with HI diagnosed at Guangdong Women and Children Hospital between 2017 and 2024 were selected as study subjects. Clinical and laboratory data were collected and reviewed. Whole exome sequencing (WES) was carried out, and candidate variants were verified by bioinformatic analysis. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 202401024). RESULTS: The five fetuses had presented with ectropion, eclabium and contracture and flexion of fingers and toes. WES revealed that all had harbored compound heterozygous or homozygous variants of the ABCA12 gene. Among the eight types of variants, five were unreported previously. CONCLUSION The compound heterozygous or homozygous variants of the ABCA12 gene probably underlay the HI in the five fetuses. Clinicians should be vigilant about the possibility of HI in fetus with ectropion, eclabium, and contracture and flexion of fingers and toes.
Humans ; Ichthyosis, Lamellar/genetics* ; Female ; ATP-Binding Cassette Transporters/genetics* ; Pregnancy ; Genotype ; Phenotype ; Exome Sequencing ; Fetus ; Mutation ; Male ; Adult

Objective To investigate the relationship between the threonine and tyrosine kinase(TTK)gene and eyelid basal cell carcinoma(BCC).Methods Bioinformatics methods were used to screen the core gene(namely,TTK)associated with the occurrence and development of BCC from the Gene Expression Omnibus(GEO)database.Surgically removed eyelid BCC tissue specimens(BCC cells were divided into BBC Grade Ⅰ,Ⅱ and Ⅲ groups by tumor grade)and be-nign tumor tissue specimens(Control group)were collected from Ziyang Central Hospital for subsequent experiments.Cel-lular immunofluorescence assay(CIA)was used to detect the expression of the TTK gene in benign and malignant eyelid tumor cells.After knocking down TTK in BCC cells through transfection with lentiviruses(the cells transfected with LV-TTK-shRNA were taken as the TTK-shRNA group,and those transfected with LV-BBC-shRNA were taken as the BBC nega-tive control group),CIA was used to detect the expression of key proteins Bcl-2 and Bax in the apoptotic signaling pathway of each group of cells.Results The bioinformatics analysis showed that the TTK gene was the core gene associated with the occurrence and development of eyelid BCC.CIA detection results revealed that the fluorescence signal intensities in the tumor cytoplasm of Control,BCC Grade Ⅰ,Ⅱ,and Ⅲ groups were 1.03±0.07,1.28±0.11,1.58±0.13 and 1.92±0.17,respectively.The fluorescence signal intensity gradually increased,and the difference in fluorescence signal intensity among the four groups was statistically significant(all P＜0.05).Compared with that in the Control group(1.02±0.05),the cell fluorescence intensity was increased in the BCC negative control group(1.74±0.12)and decreased in the TTK-shRNA group(1.31±0.09)(P＜0.05).The difference in cell fluorescence intensity was significant among the Control,BCC nega-tive control and TTK-shRNA groups(all P＜0.05).The fluorescence intensity of the anti-apoptotic protein Bcl-2 was 1.04±0.12 in the Control group,2.12±0.23 in the BCC negative control group,and 1.43±0.15 in the TTK-shRNA group.The fluorescence intensity of the pro-apoptotic protein Bax was 1.02±0.08 in the Control group,0.64±0.11 in the BCC negative control group,and 1.47±0.16 in the TTK-shRNA group.After TTK knockdown,the expression level of BcL-2 in BCC cells decreased,and that of Bax increased.The fluorescence intensities of BcL-2 and Bax were significantly different among the Control,BCC negative control and TTK-shRNA groups(all P＜0.05).Conclusion The TTK gene plays a role in the regulation of eyelid BCC cell proliferation,and this effect is closely related to the PI3K-AKT-Bcl-2/Bax signaling path-way.

Objective To evaluate the effectiveness of different tip positions applied to midline catheters(MC)and provide evidence-based evidence for venous catheter tip positioning in clinical practice.Methods Computerized searches of PubMed,Web of Science,Embase,Cochrane Library,CINAHL,CNKI,Wanfang Database,VIP,and CBM for studies on the effectiveness of applying MC with different tip positions were performed from the time of database construction to July 2024.Meta-analysis was performed using Rev Man 5.3 software after 2 investigators independently screened the studies,extracted the information and evaluated the quality of the included studies.Results A total of 9 studies with 2 302 hospitalized patients were included.The quality evaluation results of the included studies are all B-level.Meta-analysis showed that when the tip of the MC was located in the subclavian vein compared with the tip of the MC in the axillary vein,the rate of total catheter-related complications,phlebitis,blood leakage,infiltration,catheter occlusion,catheter dislocation,and catheter-associated thrombosis were lower,with a statistically significant difference(P＜0.05).When the tip of the MC was located in the subclavian vein compared with the tip of the MC in the axillary vein,the catheter retention time was longer,with a statistically significant difference(P=0.007).The descriptive analysis showed a lower rate of extubation due to complications when the tip of the MC was located in the subclavian vein compared with when the tip was located in the axillary vein(P＜0.05).Conclusion When the tip of the MC is located in the subclavian vein compared to when it is located in the axillary vein,the incidence of total catheter-related complications,phlebitis,blood leakage,infiltration,catheter occlusion,catheter dislocation,catheter-associated thrombosis,and the rate of catheter extractions due to complications were lower,and the catheter was left in place for a longer period of time.Due to the limitations of the quantity and quality of the included studies,more large-sample,high-quality studies are needed to further validate the effectiveness of different tip positions of MC.