Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Objective This study aimed to investigate the seasonal variation of mosquitoes in Yantai, Shandong Province, and provide a scientific basis for mosquito and mosquito-borne disease control. Methods From March to November for each of the years between 2020 and 2023, adult mosquitoes were collected from different habitats, including parks, hospitals, urban residential areas, rural households and livestock sheds, in 13 counties of Yantai City using a mosquito trap lamp method, among which, female mosquitoes were separated and identified, and the numbers were counted. We used the circular distribution method to analyze the temporal distribution characteristics of mosquito density. Results The γ values obtained for mosquitoes in Yantai from 2020 to 2023, the distribution of mosquitoes in different habitats, and dominant mosquito species in different months showed strong seasonality, with values ranging from 0.7461 to 0.8531(P ＜ 0.05). The peak period of seasonal variation in mosquitoes occurred from June 28thto September 13th, with August 5thbeing identified as the peak day. The peak periods of seasonal variation in mosquitoes in residential areas, parks, hospitals, peasant households, and animals sheds were observed from June 24thto September 14th, June 25thto September 10th, June 22ndto September 12th, July 1stto September 9th, and July 2ndto September 17th, respectively, with corresponding peak days on August 4th,3rd, 2nd, 5th, and 9th, respectively. The peak periods of Culex pipiens pallens, Aedes albopictus, and Anopheles sinensis were from June 26thto September 11th, June 28thto September 17th, and July 12thto September 17th, respectively, with corresponding peak days on August 3rd,7th, and 14th, respectively. Conclusions Our findings in this study revealed that the peak of mosquito activity in Yantai was concentrated in early August, with a peak period extending from June 28thto September 13th, and there were differences between different habitats(with peak periods for rural households and livestock sheds occurring later than those in residential areas, parks, and hospitals). Moreover, with respect to the mosquito species, populations of Cx. pipiens pallens and Ae. albopictus peaked earlier than those of An. sinensis. Based on these findings, we recommend that city-wide mosquito control work should commence in late June, and include appropriate early prevention and control measures for key habitats, such as livestock sheds, and dominant mosquito species, such as Cx. pipiens pallens, to minimize the density of mosquito vectors and the risk of disease transmission.

Objective To investigate the efficacy of the ultraviolet A-riboflavin cross-linking corneal stromal lenticule punctal plug for the treatment of dry eyes in rabbits.Methods Thirty-two New Zealand white rabbits(64 eyes)were se-lected and randomly divided into a normal group,a model group,a conventional plug group and a cross-linking plug group,with 8 rabbits(16 eyes)in each group.Rabbits in the normal group were not treated.In the model group,moderate-to-se-vere dry eye rabbit models were constructed but no treatment was given.Rabbits in the conventional and cross-linking plug groups were implanted with conventional and cross-linking plugs after model construction,respectively.The tear film func-tions of the experimental rabbits,including tear secretion volume(SIT),corneal fluorescein sodium staining,tear film break-up time(BUT),and tear meniscus height(TMH),were detected before the intervention,1 day,1 week,2 weeks,and 4 weeks after the intervention.In addition,the corneas of each group were collected for hematoxylin and eosin(HE)staining to observe the changes of the corneal epithelium 4 weeks after the intervention.Finally,the non-cross-linking and cross-linking corneal stromal lenticules were placed separately in 1 g·L-1 of type Ⅰ collagenase to observe the change of the lenticule diameter over time.Results In the cross-linking plug group,the SIT,BUT and TMH values 2 and 4 weeks after the intervention were significantly higher than those before the intervention(all P＜0.01).In the conventional plug group,the SIT,BUT and TMH values 4 weeks after intervention were significantly higher than those before the intervention(all P＜0.01).After 4 weeks of intervention,the corneal staining of rabbits in the cross-linking plug group was better than that in the conventional plug group and model group.The HE staining results showed that in the cross-linking plug group,the corneal epithelial thickness of rabbits was basically normal,epithelial cells were basically arranged in order,and a single layer of columnar epithelial cells was observed on the basal layer.The dissolution time of the corneal stromal lenticule after cross-linking was significantly increased,compared with that of the non-cross-linking one.Conclusion The ultraviolet A-riboflavin cross-linking corneal stromal lenticule punctal plug has a more stable therapeutic effect on the rabbit dry-eye model than the conventional one,so it is expected to provide a novel approach for the clinical treatment of dry eyes.

Objective To develop an enteral nutrition delivery device for nasal feeding patients to relieve gastrointestinal discomfort during enteral nutrition therapy and solve the problems in heating,quality preservation and constant temperature maintenance of the solution.Methods The enteral nutrition delivery device was mainly composed of a nasal feeding container,a fixing frame,a limiting trough,a heating wire,a temperature control unit and a speed control unit.The heating wire and temperature and speed control units were combined to facilitate the nasogastric solution in the container to be delivered to the patient's stomach and intestines at a constant temperature and a uniform speed.The device developed had its shell made of 304 waterproof stainless steel and the nasal feeding container made of 05-polypropylene.Results The device developed realized constant-temperature and uniform-speed delivery and auto cleaning,and could reduced effectively gastrointestinal adverse reactions during nasal feeding.Conclusion The device developed gains advantages in easy operation and autonomous feeding,and thus is worth promoting for nasal feeding patients clinically.[Chinese Medical Equipment Journal,2025,46(2):108-111]

Objective To investigate the efficacy of the ultraviolet A-riboflavin cross-linking corneal stromal lenticule punctal plug for the treatment of dry eyes in rabbits.Methods Thirty-two New Zealand white rabbits(64 eyes)were se-lected and randomly divided into a normal group,a model group,a conventional plug group and a cross-linking plug group,with 8 rabbits(16 eyes)in each group.Rabbits in the normal group were not treated.In the model group,moderate-to-se-vere dry eye rabbit models were constructed but no treatment was given.Rabbits in the conventional and cross-linking plug groups were implanted with conventional and cross-linking plugs after model construction,respectively.The tear film func-tions of the experimental rabbits,including tear secretion volume(SIT),corneal fluorescein sodium staining,tear film break-up time(BUT),and tear meniscus height(TMH),were detected before the intervention,1 day,1 week,2 weeks,and 4 weeks after the intervention.In addition,the corneas of each group were collected for hematoxylin and eosin(HE)staining to observe the changes of the corneal epithelium 4 weeks after the intervention.Finally,the non-cross-linking and cross-linking corneal stromal lenticules were placed separately in 1 g·L-1 of type Ⅰ collagenase to observe the change of the lenticule diameter over time.Results In the cross-linking plug group,the SIT,BUT and TMH values 2 and 4 weeks after the intervention were significantly higher than those before the intervention(all P＜0.01).In the conventional plug group,the SIT,BUT and TMH values 4 weeks after intervention were significantly higher than those before the intervention(all P＜0.01).After 4 weeks of intervention,the corneal staining of rabbits in the cross-linking plug group was better than that in the conventional plug group and model group.The HE staining results showed that in the cross-linking plug group,the corneal epithelial thickness of rabbits was basically normal,epithelial cells were basically arranged in order,and a single layer of columnar epithelial cells was observed on the basal layer.The dissolution time of the corneal stromal lenticule after cross-linking was significantly increased,compared with that of the non-cross-linking one.Conclusion The ultraviolet A-riboflavin cross-linking corneal stromal lenticule punctal plug has a more stable therapeutic effect on the rabbit dry-eye model than the conventional one,so it is expected to provide a novel approach for the clinical treatment of dry eyes.

(rsFC)and their relationship with negative symptoms in schizophrenia patients with predominant negative symptoms(PNS).Methods Fifty-four schizophrenia patients with PNS and sixty-one healthy controls underwent resting-state functional magnetic resonance imaging(fMRI)scans.Data were collected on general demographic information,the Positive and Negative Syndrome Scale(PANSS),the Scale for the Assessment of Negative Symptoms(SANS),and the Temporal Experience of Pleasure Scale(TEPS).Twelve striatal subregions were selected as regions of interest(ROIs)to analyze the rsFC between each ROI and whole-brain voxels.The rsFC values of areas with significant differences were extracted for Pearson correlation analysis with negative symptoms.Results Compared with healthy controls,schizophrenia patients with PNS exhibited decreased rsFC between the right dorsal caudal putamen(DCP)and right insula,left middle frontal gyrus(MFG),right median cingulate and paracingulate gyri(MCC);between the left DCP and right putamen,left insula,left MFG;between the right dorsal rostral putamen(DRP)and bilateral MFG,left insula,right MCC;between the left DRP and right insula,left rolandic operculum;between the right ventral rostral putamen(VRP)and bilateral putamen,left MFG,right MCC;between the left VRP and right insula,left putamen,bilateral MFG,right MCC,left inferior parietal gyrus,excluding supramarginal and angular gyri.Decreased rsFC was also observed between the left ventral caudate/nucleus accumbens(inferior)and right insula,left anterior cingulate cortex,supracallosal,bilateral precuneus(a threshold of P<0.001 in voxel-level with P<0.05 in cluster-lever,corrected for family-wise error,PFWE<0.05/12=0.004).No regions showed increased rsFC in schizophrenia patients with PNS relative to healthy controls.And no significant correlations were found between striatal rsFC and negative symptoms(PBonferroni>0.05).Conclusion Schizophrenia patients with PNS exhibited widespread cortical-striatal functional connectivity abnormalities,particularly reduced rsFC between the putamen and the MFG,MCC and insula.

BACKGROUND:Synthetic polymers,such as polypropylene and polyester,used for the treatment of abdominal wall defects not only lack biodegradability and bioactivity but also fail to meet the demands of complex and irregular wounds.Therefore,finding bioactive materials with low immunogenicity and good histocompatibility has become a hot spot in the repair of abdominal wall defects. OBJECTIVE:To prepare methacryloyl modified dermal extracellular matrix hydrogel and explore its potential application in abdominal wall defect. METHODS:(1)The porcine dermis was acellular with 0.25%trypsin and 1%Triton X-100 in turn to obtain the dermal extracellular matrix.After pepsin digestion and methacrylic anhydride modification,the methacrylated dermal extracellular matrix hydrogel was formed by photocrosslinking.The microscopic morphology of the hydrogel was observed by scanning electron microscope,and its rheological properties,swelling properties and other physical and chemical properties were tested.(2)Mice fibroblasts(L929)were inoculated into methacrylated dermal extracellular matrix hydrogel to detect the cell compatibility.(3)Totally 12 SD rats were randomly divided into two groups(n=6)to create abdominal wall defect model with peritoneum preserved.The defect site of the polypropylene group was filled with polypropylene material,and the hydrogel group was filled with methacrylated dermal extracellular matrix hydrogel.The wound skin of both groups was covered with polypropylene material.The wound healing was observed and histological analysis was carried out. RESULTS AND CONCLUSION:(1)Enzymatic hydrolysis had a good decellularization effect on porcine dermis after decellularization,and the original glycosaminoglycans and collagen were well retained.Scanning electron microscope observation revealed that the dermal extracellular matrix hydrogel presented loose and porous structure.The aperture was between 70 and 120 μm.The swelling ratio was(16.88±3.24)%and the water absorption was(94.24±1.11)%.The rheological property test showed that the methacrylated dermal extracellular matrix hydrogel was stable and had shear thinning characteristics,with injectability.(2)CCK-8 assay and live/dead staining showed that methacrylated dermal extracellular matrix hydrogel had good cell compatibility.(3)The results of animal experiments showed that the skin wound healing rate of the experimental group was higher than that of the control group at 7,10,and 14 days after operation(P<0.05).Hematoxylin-eosin and Masson staining of skin and muscle tissue exhibited that compared with the polypropylene group,the skin wound epithelialization,hair follicle formation,collagen fiber arrangement,and neovascularization were better in the hydrogel group 14 days after surgery.The skin wound new tissue structure was similar to the normal tissue at 28 days after surgery,and scar hyperplasia was less.A small amount of muscle regeneration was observed on day 28 after operation.(4)The results show that the methacrylated dermal extracellular matrix hydrogel can promote wound skin healing and muscle tissue regeneration in rats with abdominal wall defect.

Objective:This study aims to evaluate the effectiveness of the 4C continuous care model in home enteral nutrition management for patients after gastric cancer surgery.Methods:A control group consisting of 40 gastric cancer patients who were hospitalized in the Department of Gastrointestinal Surgery of Suzhou Ninth People's Hospital from January 2022 to June 2022 was chosen.This group received traditional nutritional management guidance,which included nutritional screening and assessment,nutritional monitoring,providing personalized nutritional guidance for each patient,and follow-ups via telephone and outpatient visits.An observation group consisting of 40 gastric cancer patients admitted between July 2022 and January 2023 received the same basic care as the control group,with the addition of the 4C continuous care plan based on an internet platform to improve their enteral nutrition status.The nutritional indicators of both groups were compared at 1 month,3 months,and 6 months post-intervention.Additionally,the results of the Nutritional Risk Screening(NRS 2002)and Patient-Generated Subjective Global Assessment(PG-SGA)at discharge and 6 months post-discharge were compared between the two groups.Results:At 1 month,3 months,and 6 months post-intervention,the observation group showed an increase in indicators such as albumin,prealbumin,hemoglobin,upper limb grip strength,and triceps skinfold thickness compared to the control group(P<0.05).At 6 months post-intervention,the PG-SGA and NRS 2002 scores in the observation group were improved compared to the control group(P<0.05).Conclusion:The implementation of the 4C continuous care model on an internet platform significantly improves home enteral nutrition status for patients after gastric cancer surgery.

Patients suffering from nerve injury often experience exacerbated pain responses and complain of memory deficits. The dorsal hippocampus (dHPC), a well-defined region responsible for learning and memory, displays maladaptive plasticity upon injury, which is assumed to underlie pain hypersensitivity and cognitive deficits. However, much attention has thus far been paid to intracellular mechanisms of plasticity rather than extracellular alterations that might trigger and facilitate intracellular changes. Emerging evidence has shown that nerve injury alters the microarchitecture of the extracellular matrix (ECM) and decreases ECM rigidity in the dHPC. Despite this, it remains elusive which element of the ECM in the dHPC is affected and how it contributes to neuropathic pain and comorbid cognitive deficits. Laminin, a key element of the ECM, consists of α-, β-, and γ-chains and has been implicated in several pathophysiological processes. Here, we showed that peripheral nerve injury downregulates laminin β1 (LAMB1) in the dHPC. Silencing of hippocampal LAMB1 exacerbates pain sensitivity and induces cognitive dysfunction. Further mechanistic analysis revealed that loss of hippocampal LAMB1 causes dysregulated Src/NR2A signaling cascades via interaction with integrin β1, leading to decreased Ca²⁺ levels in pyramidal neurons, which in turn orchestrates structural and functional plasticity and eventually results in exaggerated pain responses and cognitive deficits. In this study, we shed new light on the functional capability of hippocampal ECM LAMB1 in the modulation of neuropathic pain and comorbid cognitive deficits, and reveal a mechanism that conveys extracellular alterations to intracellular plasticity. Moreover, we identified hippocampal LAMB1/integrin β1 signaling as a potential therapeutic target for the treatment of neuropathic pain and related memory loss.
Animals ; Laminin/genetics* ; Hippocampus/metabolism* ; Neuralgia/metabolism* ; Cognitive Dysfunction/etiology* ; Male ; Peripheral Nerve Injuries/metabolism* ; Extracellular Matrix/metabolism* ; Integrin beta1/metabolism* ; Pyramidal Cells/metabolism* ; Signal Transduction