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.

A method was developed for determination of dilauryl thiodipropionate(DLTDP)in fried foods by coupling solid-phase extraction(SPE)pretreatment with reverse-phase liquid chromatography-tandem mass spectrometry(RPLC-MS/MS)detection.Samples were extracted with n-hexane as the solvent,purified using a neutral alumina SPE cartridge,and finally analyzed by RPLC-MS/MS.Quantitative analysis was performed using matrix-matched calibration curves combined with an external standard method under optimal experimental conditions.The results showed that DLTDP exhibited good linearity in the range of 2.0-50.0 μg/L,with a correlation coefficient(R2)≥0.999.The limit of detection(LOD)and the limit of quantification(LOQ)of the method were 0.15 mg/kg and 0.5 mg/kg,respectively.The mean recoveries at three fortification levels(0.5,1.0,and 200 mg/kg)in different samples ranged from 84.8%to 96.8%,with the relative standard deviations(RSDs)all less than 8.0%.The developed method was highly sensitive,accurate and reliable,and easy to operate,making it well suited for the routine quantitative analysis of DLTDP in fried foods.

Objective To evaluate the feasibility and effectiveness of 3D digital holographic imaging combined with intraoperative navigation technology in the context of partial nephrectomy.Methods A total of 46 patients who underwent laparoscopic partial nephrectomy in the Department of Urology at the Second People's Hospital of Hefei City between June 2023 and January 2025 were randomly assigned to either the experimental group or the control group.The experimental group(n=23)utilized preoperative planning and intraoperative real-time navigation based on 3D digital holographic imaging,whereas the control group(n=23)relied on preoperative planning using optimized two-dimensional images obtained via contrast-enhanced CT and MRI scans.Preoperative data—including gender,age,body mass index(BMI),tumor diameter,and RENAL score—were collected.Intra-operative parameters such as total operative time,warm ischemia time,intraoperative blood loss,hemoglobin levels,postoperative hospitalization duration,and time to drain removal were recorded.Renal function changes were assessed by comparing serum creatinine levels and estimated glomerular filtration rates(eGFR)before surgery and one month post-surgery.Additionally,the incidence of intraoperative complications—particularly injury to the renal collecting system—and postoperative complications—including positive surgical margins,bleeding,subcutaneous emphysema,and urinary fistula—was analyzed.Results In this study,holographic images were successfully reconstructed for 23 patients with renal tumors in the experimental group.Each anatomical structure—including the kidney and tumor lesions,collecting system,renal arteries and veins,adrenal glands,and inferior vena cava—was color-coded to enable intuitive visualization.These images were used for preoperative planning and provided real-time spatial orientation to accurately locate and guide resection of the tumor during surgery.In the control group,23 patients underwent preoperative planning based on contrast-enhanced CT and MRI scans acquired using optimized parameters.All 46 patients underwent laparoscopic partial nephrectomy performed by the same qualified surgeon,and postoperative pathological analysis confirmed renal tumors,including 27 cases of clear cell carcinoma,7 cases of chromophobe cell carcinoma,5 cases of papillary cell carcinoma,2 cases of sarcomatoid carcinoma,and 5 cases of angiomyolipoma.No significant differences were observed in baseline clinical characteristics(including age,body mass index,tumor diameter,and RENAL score)between the two groups(P＞0.05).The experimental group showed significantly lower values in total operative time,warm ischemia time,intraoperative blood loss,pre-to postoperative hemoglobin changes,and pre-surgical to one-month post-surgical creatinine changes compared to the control group(P＜0.01).Additionally,the experimental group exhibited smaller changes in hospitalization duration,time to drain removal,and glomerular filtration rate from preoperative to one month post-surgery;however,these differences were not statistically significant(P=0.175,P=0.331,and P=0.273).There were no intraop-erative complications or damage to the collecting system in either the experimental or control groups.Postopera-tively,the control group experienced one case of positive surgical margin,one case of hemorrhage,and one case of subcutaneous emphysema.No statistically significant differences were observed between the groups(P＞0.05).Conclusions 3D digital holographic imaging combined with intraoperative navigation technology,based on the fusion of MRI and CT data,facilitates preoperative planning and precise intraoperative guidance.This approach helps reduce operative time,preserve renal function,and lower perioperative risks while ensuring therapeutic efficacy.

Objective To summarize the imaging characteristics of occult rib fracture(ORF),analyze the causes of missed diagnosis and misdiagnosis of ORF,and explore strategies to improve the detection rate of ORF.Methods A total of 142 patients with rib fractures who underwent multi spiral computed tomography(MSCT)were selected.The initial examination was conducted within 1 week after the injury,and follow-up examinations were performed at multiple time points after 1 week post-injury.A retrospective analysis was conducted to review the fracture detection and locations during the follow-up period.The time of fracture edge sclerosis or callus growth was observed in the young group(17 cases),middle-aged group(64 cases),and elderly group(61 cases).Results The anterior segment of the ribs was the predilection site for occult fractures,with 199 cases(53.4％).The missed diagnosis rates of fracture were higher for fractures near the costal cartilage segment and the posterior segment of the ribs,with missed diagnosis rates of 49.4％and 58.8％,respectively.Compared with the number of rib fractures identified in the initial examination,there was a statistically significant difference in the number of rib fractures at 3-6 weeks after injury(P＜0.05).The time of local sclerosis or callus growth in the young,middle-aged and elderly groups was(18.76±3.849)d,(26.14±6.597)d,and(37.69±5.726)d,respectively,with statistically significantl differences between the groups(P＜0.05).Conclusion MSCT has certain limits in diagnosing ORF in the short term after injury.Primarily observing the predilection sites and missed sites of occult fractures,systematically recognizing the imaging characteristics of ORF,and adopting the optimal detection-time window for patients of different age groups can reduce the missed diagnosis rate and misdiagnosis rate of ORF and improve the detection rate of fractures.This provides accurate and objective basis for clinical and forensic identification,with significant clinical importance and application value.

Objective:To explore the efficacy of deep learning-based automatic segmentation technology in the segmentation of hepatocellular carcinoma (HCC) lesions using gadoxetate disodium-enhanced MRI (EOB-MRI), and to investigate the prognostic value of radiomics analysis in predicting patient outcomes.Methods:This was a cross-sectional, retrospective study that collected data from 352 patients with solitary HCC who underwent imaging at the Harbin Medical University Cancer Hospital between June 2015 and May 2023. The patients were randomly divided into a training set ( n=213) and a validation set ( n=139) in a 3∶2 ratio using weighted random sampling. Two radiologists manually annotated the lesions. Hepatobiliary-phase EOB-MRI images were standardized, and six deep learning models,nnU-Net, nnFormer, UnetR, Swin-UnetR, UnetR++ and MedNeXt,were trained for automatic segmentation on the training set. The segmentation performance was evaluated on the validation set, and the segmentation efficacy was assessed using the Dice coefficient and 95% Hausdorff distance (HD 95), identifying of the optimal model. Radiomics features were extracted from both manual and automatic segmentation regions, and the radiomics score (Radscore) was calculated to stratify patients into high-risk and low-risk groups. Kaplan-Meier curves and log-rank tests were used to analyze the differences in relapse-free survival (RFS) and overall survival (OS) between the different stratified groups. Results:Among the automatic segmentation models, the MedNeXt model performed best in the validation set, with a Dice coefficient of 76.0%, HD 95 of 7.2, and a segmentation success rate of 90.6% (126/139). The nnFormer model was the second-best, with a Dice coefficient of 75.3%, HD 95 of 10.1, and a segmentation success rate of 89.9% (125/139). Other models showed Dice coefficients ranging from 66.3% to 74.1%. A MedNext-nnF model was established by combining the MedNeXt and nnFormer models, achieving a Dice coefficient of 78.2%, HD 95 of 5.9, and a segmentation success rate of 92.1% (128/139) in the validation group. After constructing the automatic segmentation radiomics prognostic model, patients were stratified by Radscore. Both manual and automatic segmentation models showed statistically significant differences in RFS and OS between different risk groups ( P<0.001). Conclusions:The Mednext-nnF fusion model enables efficient and automated segmentation of HCC lesions in EOB-MRI. The radiomics model constructed based on the automated segmentation demonstrates strong performance in predicting and stratifying prognostic risk.

Objective To compare the efficacy of testicular repositioning and fixation combined with decompression of the testicular fascial compartment (testicular leucotomy+sheath flap repair) versus conventional testicular repositioning and fixation in surgery for testicular torsion in children. Methods Fifty-six patients with testicular torsion admitted to Hebei Provincial Children's Hospital from January 2019 to October 2023 were selected and divided into the observation group (26 cases) and the control group (30 cases),and the observation group was treated with testicular reorientation and fixation+testicular fascial compartment decompression,while the control group was treated with conventional testicular reorientation and fixation. There was no statistically significant difference in the age and left and right sides of the patients in the two groups (P>0.05). The intraop-erative bleeding,postoperative testicular atrophy,the presence of postoperative scrotal infection and postoperative hospitalization time of the two groups were compared. Results All patients successfully completed the operation without intraoperative complications. There was no statistically significant difference between the observation group and the control group in terms of intraoperative bleeding,postoperative scrotal infection rate and postoperative hospitalization time (P>0.05);the postoperative testicular atrophy rate of the observation group was significantly lower than that of the control group (P<0.05). Conclusions Testicular restoration and fixation+testicular fascial compartment decompression can effectively reduce the pressure of testicular fascial compartment,reduce the ischemia-reperfusion injury of testis,and reduce the occurrence of testicular atrophy,which is safe and effective in the treatment of testicular torsion in children.

Objective To summarize the imaging characteristics of occult rib fracture(ORF),analyze the causes of missed diagnosis and misdiagnosis of ORF,and explore strategies to improve the detection rate of ORF.Methods A total of 142 patients with rib fractures who underwent multi spiral computed tomography(MSCT)were selected.The initial examination was conducted within 1 week after the injury,and follow-up examinations were performed at multiple time points after 1 week post-injury.A retrospective analysis was conducted to review the fracture detection and locations during the follow-up period.The time of fracture edge sclerosis or callus growth was observed in the young group(17 cases),middle-aged group(64 cases),and elderly group(61 cases).Results The anterior segment of the ribs was the predilection site for occult fractures,with 199 cases(53.4％).The missed diagnosis rates of fracture were higher for fractures near the costal cartilage segment and the posterior segment of the ribs,with missed diagnosis rates of 49.4％and 58.8％,respectively.Compared with the number of rib fractures identified in the initial examination,there was a statistically significant difference in the number of rib fractures at 3-6 weeks after injury(P＜0.05).The time of local sclerosis or callus growth in the young,middle-aged and elderly groups was(18.76±3.849)d,(26.14±6.597)d,and(37.69±5.726)d,respectively,with statistically significantl differences between the groups(P＜0.05).Conclusion MSCT has certain limits in diagnosing ORF in the short term after injury.Primarily observing the predilection sites and missed sites of occult fractures,systematically recognizing the imaging characteristics of ORF,and adopting the optimal detection-time window for patients of different age groups can reduce the missed diagnosis rate and misdiagnosis rate of ORF and improve the detection rate of fractures.This provides accurate and objective basis for clinical and forensic identification,with significant clinical importance and application value.

Objective:To explore the efficacy of deep learning-based automatic segmentation technology in the segmentation of hepatocellular carcinoma (HCC) lesions using gadoxetate disodium-enhanced MRI (EOB-MRI), and to investigate the prognostic value of radiomics analysis in predicting patient outcomes.Methods:This was a cross-sectional, retrospective study that collected data from 352 patients with solitary HCC who underwent imaging at the Harbin Medical University Cancer Hospital between June 2015 and May 2023. The patients were randomly divided into a training set ( n=213) and a validation set ( n=139) in a 3∶2 ratio using weighted random sampling. Two radiologists manually annotated the lesions. Hepatobiliary-phase EOB-MRI images were standardized, and six deep learning models,nnU-Net, nnFormer, UnetR, Swin-UnetR, UnetR++ and MedNeXt,were trained for automatic segmentation on the training set. The segmentation performance was evaluated on the validation set, and the segmentation efficacy was assessed using the Dice coefficient and 95% Hausdorff distance (HD 95), identifying of the optimal model. Radiomics features were extracted from both manual and automatic segmentation regions, and the radiomics score (Radscore) was calculated to stratify patients into high-risk and low-risk groups. Kaplan-Meier curves and log-rank tests were used to analyze the differences in relapse-free survival (RFS) and overall survival (OS) between the different stratified groups. Results:Among the automatic segmentation models, the MedNeXt model performed best in the validation set, with a Dice coefficient of 76.0%, HD 95 of 7.2, and a segmentation success rate of 90.6% (126/139). The nnFormer model was the second-best, with a Dice coefficient of 75.3%, HD 95 of 10.1, and a segmentation success rate of 89.9% (125/139). Other models showed Dice coefficients ranging from 66.3% to 74.1%. A MedNext-nnF model was established by combining the MedNeXt and nnFormer models, achieving a Dice coefficient of 78.2%, HD 95 of 5.9, and a segmentation success rate of 92.1% (128/139) in the validation group. After constructing the automatic segmentation radiomics prognostic model, patients were stratified by Radscore. Both manual and automatic segmentation models showed statistically significant differences in RFS and OS between different risk groups ( P<0.001). Conclusions:The Mednext-nnF fusion model enables efficient and automated segmentation of HCC lesions in EOB-MRI. The radiomics model constructed based on the automated segmentation demonstrates strong performance in predicting and stratifying prognostic risk.

OBJECTIVES: To evaluate the effectiveness of single-balloon and double-balloon enteroscopy in diagnosing pediatric small bowel diseases and assess the diagnostic efficacy of computed tomography enterography (CTE) for small bowel diseases using enteroscopy as the reference standard. METHODS: Clinical data from 576 children who underwent enteroscopy at Hunan Children's Hospital between January 2017 and December 2023 were retrospectively collected. The children were categorized based on enteroscopy type into the single-balloon enteroscopy (SBE) group (n=457) and double-balloon enteroscopy (DBE) group (n=119), and the clinical data were compared between the two groups. The sensitivity and specificity of CTE for diagnosing small bowel diseases were evaluated using enteroscopy results as the standard. RESULTS: Among the 576 children, small bowel lesions were detected by enteroscopy in 274 children (47.6%).There was no significant difference in lesion detection rates or complication rates between the SBE and DBE groups (P>0.05), but the DBE group had deeper insertion, longer procedure time, and higher complete small bowel examination rate (P<0.05). The complication rate during enteroscopy was 4.3% (25/576), with 18 cases (3.1%) of mild complications and 7 cases (1.2%) of severe complications, which improved with symptomatic treatment, surgical, or endoscopic intervention. Among the 412 children who underwent CTE, the sensitivity and specificity for diagnosing small bowel diseases were 44.4% and 71.3%, respectively. CONCLUSIONS SBE and DBE have similar diagnostic efficacy for pediatric small bowel diseases, but DBE is preferred for suspected deep small bowel lesions and comprehensive small bowel examination. Enteroscopy in children demonstrates relatively good overall safety. CTE demonstrates relatively low sensitivity but comparatively high specificity for diagnosing small bowel diseases.
Retrospective Studies ; Treatment Outcome ; Double-Balloon Enteroscopy/statistics & numerical data* ; Single-Balloon Enteroscopy/statistics & numerical data* ; Humans ; Male ; Female ; Child ; Operative Time ; Tomography, X-Ray Computed/statistics & numerical data* ; Sensitivity and Specificity ; Intestine, Small/surgery* ; Intestinal Diseases/surgery*