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.

To analyze the ethnic differences in the genotype distribution of thalassemia between the Han and Li ethnic groups in the Qiongnan region (southern Hainan). A cross-sectional study employing a stratified multistage sampling method was conducted from January 2019 to December 2023. A total of 4 493 high-risk individuals (2 734 Han and 1 759 Li) from southern Hainan (including Sanya, Ledong, Baoting, Lingshui, and other counties) underwent thalassemia genetic testing. The genotype distribution was statistically analyzed. Inter-group comparisons were performed using χ2 test or Fisher′s exact test. The results showed an overall thalassemia positivity rate of 66.70% (2 997/4 493), with carrier, intermediate and major thalassemia rates of 62.01% (2 786/4 493), 3.98% (179/4 493) and 0.71% (32/4 493), respectively. The positivity rates for thalassemia were 87.83% (1 545/1 759) in the Li ethnic group and 53.11% (1 452/2 734) in the Han ethnic group. Among them, the Li ethnic group exhibited significantly higher positivity rates for α-thalassemia (71.12% vs. 40.64%, χ2=398.90, P<0.001) and α/β-compound thalassemia (13.36% vs. 3.33%, χ2=160.06, P<0.001) compared to the Han ethnic group, whereas the Han ethnic group had a higher β-thalassemia rate (9.14% vs. 3.35%, χ2=56.03, P<0.001). Both ethnic groups shared common α-thalassemia alleles (-α 3.7 and -α 4.2), but the -- SEA allele proportion was significantly higher in Han (21.33% vs. 4.34%, χ2=231.45, P<0.001). Six rare -α 21.9 mutations (0.26%) were exclusively identified in the Li ethnic group, whereas none were found in Han. For β-thalassemia, the β CD41-42 allele was predominant in Li (96.60% vs. 71.01%, χ2=77.24, P<0.001), whereas other alleles (β IVS-II-654, β CD71-72, β CD17, and β -28) were more prevalent in Han (11.01%, 6.96%, 4.64%, and 3.19% vs. 1.54%, 0.00%, 0.31%, and 0.62%, respectively),all P<0.05. In conclusion, distinct ethnic disparities in thalassemia genotype distribution are observed in southern Hainan. The Li ethnic group is predominantly characterized by α-thalassemia and α/β-compound genotypes with a predominant β CD41-42 mutation. In contrast, the Han ethnic group displays higher -- SEA proportion and heterogeneous β-thalassemia genotypes.

Objective To investigate influencing factors of textbook outcome(TO)in patients with pancreatic ductal adenocarcinoma undergoing minimally invasive pancreaticoduodenectomy(MIPD).Methods A retrospective analysis was conducted on the clinical data of 101 cases of pancreatic ductal adenocarcinoma treated with MIPD in our hospital from January 2020 to December 2022.According to the inclusion and exclusion criteria,89 cases were ultimately included in this study,of which 61 cases reached TO(TO group)and 28 cases did not reach TO(non-TO group).Variables with P<0.05 in univariate analysis were included in multivariate logistic regression analysis to identify independent prognostic factors of TO.Results Univariate analysis showed that there were significant differences in pancreatic duct dilation>3 mm,preoperative neutrophil lymphocyte ratio(NLR),extended hospital stay,postoperative hospitalstay,and drain fluid amylase(DFA)>1100 U/L at1-3 d aftersurgery(P<0.05).Multivariate logistic regression analysis showed that the independent prognostic factors affecting TO were:pancreatic duct dilation>3 mm(OR=7.290,95%CI:1.485-35.786,P=0.014),postoperative hospital stay(OR=0.862,95%CI:0.751-0.989,P=0.034),and the DFA on the first postoperative day>1100 U/L(OR=0.052,95%CI:0.005-0.545,P=0.014).Conclusions The outcome of TO in patients after MIPD is not related to the surgical approach(robot assisted minimally invasive pancreaticoduodenectomy or laparoscopic pancreaticoduodenectomy).Pancreatic duct dilation>3 mm,postoperative hospital stay,and DFA on the first postoperative day>1100 U/L are independent prognostic factors of TO after MIPD in patients with pancreatic ductal adenocarcinoma.

The fibrillization of α-synuclein(α-syn)is a key pathological hallmark of Parkinson's disease.Although biointerfaces play a crucial role in α-syn aggregation,the chiral regulation mechanisms remain insufficiently explored.In this work,chiral carbon dots(CD)were employed to construct nanoscale chiral interfaces,and surface-enhanced infrared absorption spectroscopy combined with nanoscale infrared spectroscopy was utilized to investigate the conformational transition ofα-syn at chiral interfaces.The results demonstrated that α-syn primarily adsorbed onto the chiral interfaces via electrostatic interactions,while spatial selectivity further modulated its conformational evolution.Notably,the D-CD interface exhibited high affinity,stabilizingα-syn in its helical conformation,whereas the L-CD and DL-CD interfaces,due to their weaker affinity,exposed aggregation-prone regions,thereby promotingβ-sheet formation and leading to the generation of oligomers and fibrils.This work elucidated the regulatory role of chiral interfaces inα-syn aggregation,providing theoretical insights for the design of protein aggregation inhibitors.

Using surface-enhanced infrared absorption spectroscopy in conjunction with electrochemical techniques,this study investigates the origins of variations in electrocatalytic activity of 4-nitrothiophenol(4-NTP)under the influence of three cations:Li+,Na+,and tetramethylammonium(TMA+).The findings highlight the significant impact of specific interactions between cations and the electrode surface on electrocatalytic activity.By constructing vibrational Stark spectra,the study reveals the impact of cations on the structure of the electric double layer and the interfacial electric field.Further spectroscopic and electrochemical characterizations demonstrate that differences in the hydrophilic and hydrophobic properties of cations influence their specific interactions with the interface.Notably,TMA+,through specific interactions,acts as a mediator for charge transfer,effectively reducing the charge transfer resistance of the system and thereby enhancing electrocatalytic activity to some extent.These results elucidate the influence of specific cation/interface interactions and cation properties on electrocatalytic reactions,contributing to a deeper understanding of cation effects at electrochemical charged interfaces.

By summarizing the mass spectrometric fragmentation patterns of oxyphenisatin substances,an analytical method was established for screening of illegally added oxyphenisatin compounds in weight-loss health foods using high performance liquid chromatography-in-source-fragmentation-quadrupole time-of-flight mass spectrometry(HPLC-ISF-QTOF-MS),along with a quantitative method for 11 kinds of oxyphenisatin compounds.Based on the developed screening method,an oxyphenisatin derivative was discovered in the reference standards,which was tentatively identified as 4-(3-(4-hydroxyphenyl)-2-oxoindolin-3-yl)phenyl acetate and confirmed by MS/MS analysis.The results showed that all 11 kinds of oxyphenisatin compounds had correlation coefficients greater than 0.9971,with limits of detection(LODs)ranging from 0.12 to 0.68 μg/L and limits of quantification(LOQ)from 0.21 to 2.29 μg/L.The LODs for 11 kinds of characteristic ions ranged from 0.45 to 9.11 μg/kg.At spiking levels of 25,50 and 100 μg/kg,the recoveries ranged from 78.9%to 117.3%.The instrumental precision,intra-day method precision and inter-day method precision were 0.23%?1.70%,0.7%?2.4%,and 1.1%?3.3%,respectively.The developed targeted and non-targeted detection method demonstrated high sensitivity,strong stability,rapid analysis,and an expanded screening range for oxyphenisatin substances,and provided robust technical support for regulatory authorities in combating illegal adulteration.

Objective:To investigate the clinical diagnosis,treatment and prognosis of traumatic ectopic testis with torsion.Methods:We retrospectively analyzed the clinical data on a case of traumatic ectopic testis with torsion and reviewed relevant litera-ture.Results:After diagnosed with traumatic ectopic testis with torsion,the patient underwent exploratory operation for confirmation of orchiocatabasis,followed by testicular reduction and fixation.Follow-up visit at 1 month after surgery showed good blood supply and no obvious testicular atrophy.Conclusion:Traumatic ectopic testis with torsion is an extremely rare emergency condition,for which color Doppler ultrasonography is an effective means of examination.Once suspected of or confirmed with the problem,the patient should receive exploratory surgery,testicular reduction and fixation within 6 hours,and close postoperative observation.

To analyze the ethnic differences in the genotype distribution of thalassemia between the Han and Li ethnic groups in the Qiongnan region (southern Hainan). A cross-sectional study employing a stratified multistage sampling method was conducted from January 2019 to December 2023. A total of 4 493 high-risk individuals (2 734 Han and 1 759 Li) from southern Hainan (including Sanya, Ledong, Baoting, Lingshui, and other counties) underwent thalassemia genetic testing. The genotype distribution was statistically analyzed. Inter-group comparisons were performed using χ2 test or Fisher′s exact test. The results showed an overall thalassemia positivity rate of 66.70% (2 997/4 493), with carrier, intermediate and major thalassemia rates of 62.01% (2 786/4 493), 3.98% (179/4 493) and 0.71% (32/4 493), respectively. The positivity rates for thalassemia were 87.83% (1 545/1 759) in the Li ethnic group and 53.11% (1 452/2 734) in the Han ethnic group. Among them, the Li ethnic group exhibited significantly higher positivity rates for α-thalassemia (71.12% vs. 40.64%, χ2=398.90, P<0.001) and α/β-compound thalassemia (13.36% vs. 3.33%, χ2=160.06, P<0.001) compared to the Han ethnic group, whereas the Han ethnic group had a higher β-thalassemia rate (9.14% vs. 3.35%, χ2=56.03, P<0.001). Both ethnic groups shared common α-thalassemia alleles (-α 3.7 and -α 4.2), but the -- SEA allele proportion was significantly higher in Han (21.33% vs. 4.34%, χ2=231.45, P<0.001). Six rare -α 21.9 mutations (0.26%) were exclusively identified in the Li ethnic group, whereas none were found in Han. For β-thalassemia, the β CD41-42 allele was predominant in Li (96.60% vs. 71.01%, χ2=77.24, P<0.001), whereas other alleles (β IVS-II-654, β CD71-72, β CD17, and β -28) were more prevalent in Han (11.01%, 6.96%, 4.64%, and 3.19% vs. 1.54%, 0.00%, 0.31%, and 0.62%, respectively),all P<0.05. In conclusion, distinct ethnic disparities in thalassemia genotype distribution are observed in southern Hainan. The Li ethnic group is predominantly characterized by α-thalassemia and α/β-compound genotypes with a predominant β CD41-42 mutation. In contrast, the Han ethnic group displays higher -- SEA proportion and heterogeneous β-thalassemia genotypes.

AIM To establish a rapid quantitative analysis model for saponins in Paris polyphylla var.yunnanensis(PPY)by near infrared spectroscopy.METHODS The contents of polyphyllins Ⅰ,Ⅱ,Ⅶ and there total content in PPY were determined by HPLC,while spectral data within the range of 10 000 to 4 000 cm-1 were collected.A quantitative analysis model was established by combining these data with partial least squares regression(PLSR).Multivariate scatter correction(MSC)and vector normalization(SNV)were applied prior to further preprocessing the spectra with original,first-order derivative(1stD),or second-order derivative(2ndD)treatments.Lastly,the model was optimized through non-smoothing(NS),Norris Derivative filtering(Nd),and Savitzky-Golay filtering(S-G)method.Model stability was evaluated based on correlation coefficients and variance.The predicted contents of each saponin component in the validation set samples were calculated.RESULTS The contents of polyphyllins Ⅰ,Ⅱ,Ⅶ were 0.42-17.98,0.46-10.44,0.23-3.86 mg/g,respectively.The total content ranged from 2.91 to 22.1 mg/g.The optimal parameters of three saponins were achieved when selecting the MSC+2ndD+S-G pretreatment method.The corresponding ratio of line segment length to segment gap was 13∶5,15∶5,11∶5,with correlation coefficients of 0.982,0.930,0.958,respectively.The root mean square errors of calibration(RMSEC)were 0.702,0.797,0.238,and the root mean square errors of prediction(RMSEP)were 1.120,0.835,0.304,respectively.The optimal parameters for the total content were obtained when selecting the MSC+2ndD+NS pretreatment method,with a correlation coefficient of 0.970,a RMSEC of 1.090,and a RMSEP of 1.740.CONCLUSION This accurate and rapid method can be used for detection of saponin contents in P.Polyphylla.