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.

ObjectiveTo investigate the mechanism by which the Zishen Huoxue prescription （ZSHXP） ameliorates cognitive dysfunction in rats with vascular dementia （VD） induced by the bilateral common carotid artery ligation （2-VO model rats） through regulating the glucose-regulated protein 78 （GRP78）/protein kinase R-like endoplasmic reticulum kinase （PERK）/activating transcription factor 4 （ATF4） signaling pathway. MethodsA VD rat model was established via the 2-VO method. A total of 72 male Sprague-Dawley （SD） rats were randomly divided into six groups： Sham group， Model group， donepezil hydrochloride group （0.45 mg·kg^-1）， and ZSHXP groups at low （8.90 g·kg^-1）， medium （17.80 g·kg^-1）， and high （35.60 g·kg^-1） doses，with 12 rats in each group. The Morris Water Maze test was utilized to assess spatial learning and memory abilities of rats， and the Novel Object Recognition test was used to evaluate cognitive performance. Hematoxylin-eosin （HE） and Nissl staining were applied to observe the histological and morphological changes in hippocampal tissues. Transmission electron microscopy （TEM） was used to observe the morphological changes of endoplasmic reticulum in rat hippocampal neurons. Immunofluorescence staining was adopted to detect the colocalization of neuronal nuclei antigen （NeuN） with GRP78 and βⅢ Tubulin with gasdermin D （GSDMD） in hippocampal neurons. Western blot was used to detect the expression levels of endoplasmic reticulum stress （ERS）-related proteins including GRP78， PERK， ATF4， phosphorylated protein kinase R-like endoplasmic reticulum kinase （p-PERK）， C/EBP homologous protein （CHOP）， NOD-like receptor protein 3 （NLRP3）， Caspase-1 and GSDMD. ResultsCompared with the sham operation group， the model group showed a significantly prolonged escape latency （P<0.01）， a significant decrease in the number of platform crossings and the residence time in the target quadrant （P<0.01）， and a markedly reduced recognition index （P<0.01）. Histological observations revealed that the hippocampal neurons in the model group were disorderly arranged with reduced quantity， deformed and shrunken cell bodies， and pyknotic and hyperchromatic nuclei. The number of Nissl bodies decreased significantly. The number of endoplasmic reticula reduced obviously， accompanied by abnormal dilation and swelling， and the loss of normal folding structure. The fluorescence colocalization of NeuN with GRP78 and βⅢ Tubulin with GSDMD in the hippocampus was significantly increased in the model group. The protein expression levels of GRP78， p-PERK/PERK， ATF4， CHOP， NLRP3， GSDMD and Caspase-1 in the model group were significantly elevated （P<0.01）. Compared with the model group， the donepezil hydrochloride group and the ZSHXP medium- and high-dose groups had a significantly shortened escape latency （P<0.01） and an increased number of platform crossings （P<0.05， P<0.01）. The residence time in the target quadrant was increased in the donepezil hydrochloride group and all ZSHXP groups （P<0.05， P<0.01）， with a significantly improved recognition index （P<0.01）. In the donepezil hydrochloride group and all ZSHXP groups， the number of hippocampal neurons increased with a more compact arrangement and reduced nuclear hyperchromasia. The number of Nissl bodies increased with morphological structures tending to be normal. In the ZSHXP high-dose group， the number of endoplasmic reticula increased and the folding structure was restored. The fluorescence colocalization of NeuN with GRP78 and βⅢ Tubulin with GSDMD in the hippocampus was significantly weakened in the treatment groups. In the donepezil hydrochloride group， the protein expressions of GRP78， ATF4 and CHOP were increased （P<0.01）， while the expression of p-PERK/PERK was decreased （P<0.05）. In the ZSHXP low-dose group， the expressions of GRP78， p-PERK/PERK and CHOP were elevated （P<0.05， P<0.01）. The ZSHXP medium- and high-dose groups showed a significant decrease in the protein expressions of p-PERK/PERK， ATF4 and CHOP （P<0.01）， and the high-dose group had a markedly reduced GRP78 protein expression （P<0.01）. In the donepezil hydrochloride group， the Caspase-1 protein expression was increased （P<0.01） and the NLRP3 protein expression was decreased （P<0.01）. In the ZSHXP low-dose group， the GSDMD expression was elevated （P<0.01） while the NLRP3 protein expression was reduced （P<0.01）. After treatment with medium and high doses of ZSHXP， the protein expression levels of NLRP3， GSDMD and Caspase-1 were significantly decreased （P<0.01）. ConclusionThe ameliorative effect of ZSHXP on cognitive function in 2-VO model rats may be associated with its regulation of the GRP78/PERK/ATF4 signaling pathway， which ameliorates ERS and inhibits neuronal pyroptosis.

ObjectiveTo investigate the mechanism by which the Zishen Huoxue prescription （ZSHXP） ameliorates cognitive dysfunction in rats with vascular dementia （VD） induced by the bilateral common carotid artery ligation （2-VO model rats） through regulating the glucose-regulated protein 78 （GRP78）/protein kinase R-like endoplasmic reticulum kinase （PERK）/activating transcription factor 4 （ATF4） signaling pathway. MethodsA VD rat model was established via the 2-VO method. A total of 72 male Sprague-Dawley （SD） rats were randomly divided into six groups： Sham group， Model group， donepezil hydrochloride group （0.45 mg·kg^-1）， and ZSHXP groups at low （8.90 g·kg^-1）， medium （17.80 g·kg^-1）， and high （35.60 g·kg^-1） doses，with 12 rats in each group. The Morris Water Maze test was utilized to assess spatial learning and memory abilities of rats， and the Novel Object Recognition test was used to evaluate cognitive performance. Hematoxylin-eosin （HE） and Nissl staining were applied to observe the histological and morphological changes in hippocampal tissues. Transmission electron microscopy （TEM） was used to observe the morphological changes of endoplasmic reticulum in rat hippocampal neurons. Immunofluorescence staining was adopted to detect the colocalization of neuronal nuclei antigen （NeuN） with GRP78 and βⅢ Tubulin with gasdermin D （GSDMD） in hippocampal neurons. Western blot was used to detect the expression levels of endoplasmic reticulum stress （ERS）-related proteins including GRP78， PERK， ATF4， phosphorylated protein kinase R-like endoplasmic reticulum kinase （p-PERK）， C/EBP homologous protein （CHOP）， NOD-like receptor protein 3 （NLRP3）， Caspase-1 and GSDMD. ResultsCompared with the sham operation group， the model group showed a significantly prolonged escape latency （P<0.01）， a significant decrease in the number of platform crossings and the residence time in the target quadrant （P<0.01）， and a markedly reduced recognition index （P<0.01）. Histological observations revealed that the hippocampal neurons in the model group were disorderly arranged with reduced quantity， deformed and shrunken cell bodies， and pyknotic and hyperchromatic nuclei. The number of Nissl bodies decreased significantly. The number of endoplasmic reticula reduced obviously， accompanied by abnormal dilation and swelling， and the loss of normal folding structure. The fluorescence colocalization of NeuN with GRP78 and βⅢ Tubulin with GSDMD in the hippocampus was significantly increased in the model group. The protein expression levels of GRP78， p-PERK/PERK， ATF4， CHOP， NLRP3， GSDMD and Caspase-1 in the model group were significantly elevated （P<0.01）. Compared with the model group， the donepezil hydrochloride group and the ZSHXP medium- and high-dose groups had a significantly shortened escape latency （P<0.01） and an increased number of platform crossings （P<0.05， P<0.01）. The residence time in the target quadrant was increased in the donepezil hydrochloride group and all ZSHXP groups （P<0.05， P<0.01）， with a significantly improved recognition index （P<0.01）. In the donepezil hydrochloride group and all ZSHXP groups， the number of hippocampal neurons increased with a more compact arrangement and reduced nuclear hyperchromasia. The number of Nissl bodies increased with morphological structures tending to be normal. In the ZSHXP high-dose group， the number of endoplasmic reticula increased and the folding structure was restored. The fluorescence colocalization of NeuN with GRP78 and βⅢ Tubulin with GSDMD in the hippocampus was significantly weakened in the treatment groups. In the donepezil hydrochloride group， the protein expressions of GRP78， ATF4 and CHOP were increased （P<0.01）， while the expression of p-PERK/PERK was decreased （P<0.05）. In the ZSHXP low-dose group， the expressions of GRP78， p-PERK/PERK and CHOP were elevated （P<0.05， P<0.01）. The ZSHXP medium- and high-dose groups showed a significant decrease in the protein expressions of p-PERK/PERK， ATF4 and CHOP （P<0.01）， and the high-dose group had a markedly reduced GRP78 protein expression （P<0.01）. In the donepezil hydrochloride group， the Caspase-1 protein expression was increased （P<0.01） and the NLRP3 protein expression was decreased （P<0.01）. In the ZSHXP low-dose group， the GSDMD expression was elevated （P<0.01） while the NLRP3 protein expression was reduced （P<0.01）. After treatment with medium and high doses of ZSHXP， the protein expression levels of NLRP3， GSDMD and Caspase-1 were significantly decreased （P<0.01）. ConclusionThe ameliorative effect of ZSHXP on cognitive function in 2-VO model rats may be associated with its regulation of the GRP78/PERK/ATF4 signaling pathway， which ameliorates ERS and inhibits neuronal pyroptosis.

ObjectiveTo analyze the research hotspots and development trends in the field of spinal cord stimulation (SCS) for spinal cord injury (SCI). MethodsLiterature about SCS for SCI was retrieve from the Web of Science (WOS) Core Collection database, with a time range from January, 1999 to July, 2025. VOSviewer 1.6.20 and CiteSpace 6.4.R2 were used to analyze the annual publication volume, countries, authors, institutions, journals and keywords. ResultsA total of 636 literatures were included. From 1999 to 2025, the overall publication trend in this field showed an upward trajectory, with recent years fluctuating but tending to stabilize. The country with the most publications was the United States (429 papers), followed by Russia (98 papers) and China (70 papers). The institution with the highest number of publications was the University of California, Los Angeles (76 papers), the author with the most publications was V. Reggie Edgerton (70 papers), and the journal with the most publications was Journal of Clinical Medicine (31 papers). The most frequently cited study focused on exploring the combination of epidural spinal cord stimulation with task-specific training to restore motor function in patients with complete SCI. Keyword analysis showed that the research hotspots in this field were mainly focused on neuroregulation mechanisms, recovery of motor and autonomic nervous dysfunction, artificial intelligence, closed-loop stimulation and brain-computer interface technology innovations. In recent years, the research focus gradually shifted from basic mechanisms to personalized and precise multifunctional rehabilitation strategies. ConclusionThe field of SCS for SCI has undergone phases of basic mechanism exploration and clinical application expansion. Current research hotspots and future trends focus primarily on the development of new stimulation paradigms and combined innovative technologies.

ObjectiveTo address the limitations of the current quality standard for Polygalae Radix（PR）， which relies on a single component for quality assessment and struggles to holistically control its intrinsic quality， by constructing a comprehensive quality evaluation system integrating "macro-characterization of chemical profile， synchronous quantification of multiple index components， and quantitative analysis of multi-components by single marker（QAMS） for key component groups". This study aims to facilitate the scientific revision of the quality standard for PR. MethodsHigh performance liquid chromatography（HPLC） characteristic chromatograms were established for 11 batches of PR medicinal materials（YZ）， 10 batches of PR decoction pieces（YP）， and 10 batches of licorice-processed PR decoction pieces（ZYZ）， followed by similarity evaluation and identification of common peaks. HPLC-QAMS was developed for xanthones（sibiricaxanthone B， polygalaxanthone Ⅺ， polygalaxanthone Ⅲ） in the characteristic chromatograms. Simultaneously， the external standard method（ESM） was used to determine the contents of the corresponding xanthones and 3，6'-disinapoyl sucrose in YZ， YP， and ZYZ， followed by multivariate statistical analysis and Spearman correlation analysis. ResultsThe similarity between the characteristic chromatograms of 31 batches of PR samples and the reference chromatogram was>0.9. A total of 13 common peaks were identified， and 10 of these peaks were characterized through reference standard comparison. The successfully constructed QAMS method showed that the relative correction factors（RCFs） of sibiricaxanthone B and polygalaxanthone Ⅺ to polygalaxanthone Ⅲ were 0.76 and 0.88， and their relative retention times（RRTs） were 0.85 and 0.97， respectively. The results calculated by the QAMS method showed no significant difference from those obtained by the ESM. According to the limit standard for polygalaxanthone Ⅲ in the 2020 edition of the Pharmacopoeia of the People's Republic of China（hereinafter referred to as the Chinese Pharmacopoeia）， the pass rate of 31 batches of samples was only 19.35%. Multivariate statistical analysis indicated certain compositional differences between different batches of YZ and YP， as well as between YP and ZYZ， with 3，6'-disinapoyl sucrose identified as the main differentiating component. Furthermore， correlation analysis revealed that the content of polygalaxanthone Ⅲ was positively correlated with the contents of sibiricaxanthone B and polygalaxanthone Ⅺ， but showed no association with the content of 3，6'-disinapoyl sucrose. ConclusionIt is recommended that the content limit for polygalaxanthone Ⅲ in YZ，YP and ZYZ be revised to not less than 0.07%， or the total content of polygalaxanthone Ⅲ， sibiricaxanthone B and polygalaxanthone Ⅺ be not less than 0.18%. The newly established triple quality control model of "holistic control via characteristic chromatograms， precise quantification of oligosaccharide esters， and efficient detection of xanthones by QAMS" provides a systematic and precise solution for quality evaluation of PR and similar Chinese herbal medicines.

Background The quality of occupational health technical services is directly linked to the protection of workers' health rights and the efficacy of occupational disease prevention and control. However, the industry still faces critical challenges: sporadic instances of institutional non-compliance and persistent irregularities in professional practice continue to undermine overall service performance. Objective To assess the current quality status of occupational health technical services in Zhejiang Province and propose countermeasures for quality improvement, providing a scientific basis for policy optimization and service delivery quality enhancement. Methods A total of 69 occupational health technical service institutions in Zhejiang Province that obtained formal accreditation as of April 30, 2024, were sampled, including 3 public institutions and 66 private institutions (comprising 3 formerly Class-A, 28 formerly Class-B, 11 formerly Class-C, and 24 newly certified institutions). Following the Technical Protocol for Quality Monitoring of Occupational Health Technical Service in Zhejiang Province and the Technical Protocol for Proficiency Testing of Occupational Health Detection in Zhejiang Province, a quality assessment task force comprising national and provincial experts was established. Evaluation was conducted across four dimensions: qualification maintenance and compliance, standardization of technical services, authenticity of technical services, and proficiency testing, utilizing a combination of document review, on-site inspections, and technical skill assessments. Results The occupational health technical service institutions in Zhejiang Province were predominantly private entities (82.5%), with significant disparities in overall service quality. The pass rates for qualification maintenance and compliance, technical service standardization, technical service authenticity, and the excellence rate for laboratory proficiency testing were 81.5%, 80.7%, 97.3%, and 90.4%, respectively. Regarding qualification maintenance, the pass rates for "environmental conditions" (49.8%, 56.7%) and "instrumentation and equipment" (58.2%、65.6%) were significantly lower for formerly Class-C and newly certified institutions compared to other categories. In terms of technical standardization, "standardized on-site inspections" recorded the lowest pass rate (67.4%), with newly certified institutions at only 48.0%. Regarding technical service authenticity, formerly Class-C institutions exhibited issues such as missing raw chromatograms for blank samples (85.7% pass rate). In laboratory proficiency testing, public and formerly Class-A institutions achieved 100% excellence rates, but the performance of formerly Class-C and newly certified institutions was comparatively weak; specifically, the failure rate for organic analysis in formerly Class-C institutions reached 20%; the failure rate for dust testing items in newly certified institutions was 10.3%. Conclusion The overall quality of occupational health technical services in Zhejiang Province still requires significant improvement, particularly in basic institutional conditions, the standardization of on-site inspections, and laboratory proficiency in organic and dust analysis. Formerly Class-C and newly certified institutions should be the primary focus of quality management efforts. Differentiated regulatory strategies are recommended, alongside strengthening interim and ex-post supervision to gradually enhance the quality of occupational health technical services across all institutions.

The surgical management of empyema (excluding those caused by mycobacterium tuberculosis and non-tuberculous mycobacteria) is rapidly evolving towards minimally invasive, precise, and stepwise approaches. The traditional three-stage classification (exudative, fibrinopurulent, and organizing) has limitations in guiding dynamic clinical decision-making. For the first time, this consensus explicitly identifies two critical junctures in the pathological progression of empyema: "early transformation" (stage Ⅰ to Ⅱ) and "late transformation" (stage Ⅱ to Ⅲ), and thereby constructs a corresponding "identification-early warning-intervention" stepwise therapeutic framework. The consensus emphasizes that proactive debridement via video-assisted thoracoscopic surgery should be performed during the early transformation phase to halt disease progression. Conversely, during the late transformation phase, therapeutic goals should be rationally adjusted to prioritize adequate drainage, avoiding futile pleural decortication. Moreover, the consensus underscores the pivotal role of precise perioperative etiological diagnosis (e.g. metagenomic nest-generation sequencing) and standardized anti-infective therapy. Integrating practical experiences from multiple thoracic surgery centers in China and relevant evidence-based literature, this consensus formulates recommendations on the precise definitions of staging, surgical indications for each phase, key technical points, perioperative management, and training systems. It aims to promote the standardized and individualized surgical management of empyema, ultimately optimizing patient prognosis.

The aim of this study is to establish an gene editing method of Mesomycoplasma hyo-pneumoniae(Mhp)based on the homologous recombination principle.The restriction enzyme di-gestion and ligation method combined with gene synthesis were used to construct a shuttle plasmid to achieve replication in both Mhp and Escherichia coli(E.coli).The pGEM?-T vector was used as the skeleton.The oriC sequence of Mhp which can achieve the replication of the plasmid in Mhp was inserted into the vector.Sequences of the Spiroplasma promoter and puromycin resistance gene were then inserted into the above constructed plasmid to screen recombinant clones.The up-stream and downstream homologous arms of p97 were constructed to initiate homologous recombination.The recA gene of E.coli is inserted to improve the efficiency of homologous recom-bination.The obtained shuttle plasmid was then delivered into Mhp by electro-transformation or chemical transformation.A shuttle plasmid,pGEM?-Mhp-oriC-p 97,which can replicate in both Mhp and E.coli was constructed.With the transformation of this plasmid,the carried puromycin gene and recA gene can be expressed,the p97 gene can be edited.Finally,the genetically unstable p97 gene mutant was initially obtained.In this study,a tool for Mhp gene editing based on the principle of homologous recombination was established,which laid a foundation for the develop-ment of tools for studying the pathogenesis of Mhp.

This paper summarized the current status of infection and quality control of medical flexible endoscope (abbreviation:endoscope),which can identify that defect of the quality control of endoscopic forceps channels was a major cause of nosocomial infections of endoscopy. Based on this,a multifunctional quality control workstation with forceps channel of detecting flexible endoscope,and precision components included top ends for medical endoscopes has been developed,which can clearly display residual contaminants and damages in the forceps channels and precision components after the endoscope was reprocessed. It is contribute to enhance the quality control of reprocessing endoscope,and reduce cross-infection of endoscope.