ObjectiveTo construct a stable monoclonal human embryonic kidney 293 （HEK293） cell line expressing recombinant human coagulation factor Ⅶ （rhFⅦ） and evaluate the expression level and procoagulant bioactivity of rhFⅦ. MethodsThe plasmid pCDNA3.1-EGFP-FⅦ was transfected into HEK293 cells to verify the effectiveness of the transfection system. The plasmid pCDNA3.1-FⅦ was transfected into HEK293 cells， and monoclonal stable transfected cell lines were selected using geneticin （G418）. The transcription of the FⅦ gene was identified by reverse transcription polymerase chain reaction （RT-PCR）. The expression level of rhFⅦ in the supernatant of the monoclonal stable transfected cell line was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot. The concentration of rhFⅦ was determined by enzyme-linked immunosorbent assay （ELISA）， and the procoagulant activity of rhFⅦ was measured by human coagulation factor Ⅶ potency assay. ResultsHEK293 cells transfected with pcDNA3.1-EGFP-FⅦ showed green fluorescence， indicating that rhFⅦ was successfully expressed in the supernatant of HEK293 cells after transient transfection with pcDNA3.1-FⅦ. The monoclonal stable transfected cell line was obtained by G418 screening. RT-PCR identified that the FⅦ gene was integrated into the genome of the monoclonal stable transfected cell line. The cell viability was good as detected by Cell Counting Kit-8， and a single band of rhFⅦ was obtained by purification of the cell supernatant. The highest rhFⅦ expression was （1.27±0.09） mg/L， and the highest procoagulant activity was （380.29±13.80）%. ConclusionThe monoclonal HEK293 cell lines which can express rhFⅦ protein efficiently and stably with excellent procoagulant bioactivity is successfully screened.

Objective To explore the differences and similarities in the changes of pulp repair response after direct pulp capping with iRoot BP Plus and MTA.Methods A total of 36 male SD rats were randomly divided into 3 groups,namely iRoot BP Plus group,MTA group and blank control group.Dental pulp exposure and direct pulp capping was performed on both sides of maxillary first molars of each rat.Four rats were randomly selected and sacrificed from each group at 7,14,and 28 days postoperatively,and the specimens were taken for hematoxylin-eosin(HE)staining,and then each index was observed.Results ①From the perspective of dentin tubular formation quality,at 14 d and 28 d,there were statistical differences between iRoot BP Plus group and MTA group(P＜0.05),and iRoot BP Plus was significantly better than MTA in terms of quality of restorative dentin formation.②At 14 days after operation,iRoot BP Plus had a greater area of neodontinin than that in MTA group(P＜0.05).Conclusion Both iRoot BP Plus and MTA can promote the formation of restorative dentin bridges after direct pulp capping,and the formation quality is high.The long-term effects need to be further studied.

Objective To explore the differences and similarities in the changes of pulp repair response after direct pulp capping with iRoot BP Plus and MTA.Methods A total of 36 male SD rats were randomly divided into 3 groups,namely iRoot BP Plus group,MTA group and blank control group.Dental pulp exposure and direct pulp capping was performed on both sides of maxillary first molars of each rat.Four rats were randomly selected and sacrificed from each group at 7,14,and 28 days postoperatively,and the specimens were taken for hematoxylin-eosin(HE)staining,and then each index was observed.Results ①From the perspective of dentin tubular formation quality,at 14 d and 28 d,there were statistical differences between iRoot BP Plus group and MTA group(P＜0.05),and iRoot BP Plus was significantly better than MTA in terms of quality of restorative dentin formation.②At 14 days after operation,iRoot BP Plus had a greater area of neodontinin than that in MTA group(P＜0.05).Conclusion Both iRoot BP Plus and MTA can promote the formation of restorative dentin bridges after direct pulp capping,and the formation quality is high.The long-term effects need to be further studied.

Nanomaterials have been used in a variety of industries recently,involving foods,chemi-cals and biomedicine.There are multiple routes through which humans are exposed to nanomaterials,and their toxic effects deserve more attention.In vivo studies have confirmed that nanomaterials expo-sure can lead to toxicity in such target organs as the heart,liver,kidney,skin and nerve.The toxicity mechanism is related to changes in organelles such as the endoplasmic reticulum,lysosomes and mito-chondria.Increasing studies suggest that mitochondria are critical targets for the toxicity of nanomaterials.Mitochondrial biogenesis serves as an important mechanism for maintaining mitochondrial homeostasis,which plays a vital role in the process of nanomaterials-induced cellular toxicity.This article summarizes the current research on the effects of nanomaterials on mitochondrial biogenesis,and elaborates the mechanism through which nanomaterials disrupt mitochondrial biogenesis by triggering oxidative stress,upsetting the homeostasis of calcium ion and disturbing toxicity pathways.This article is expected to provide a reference for toxicity testing and risk assessment of nanomaterials.

BACKGROUND: Tissue engineering holds promise for vascular repair and regeneration by mimicking the extracellular matrix of blood vessels. However, achieving a functional and thick vascular wall with aligned fiber architecture by electrospinning remains a significant challenge. METHODS: A novel electrospinning setup was developed that utilizes an auxiliary electrode and a spring. The impact of process parameters on fiber size and morphology was investigated. The structure and functions of the scaffolds were evaluated through material characterization and assessments of cellular biocompatibility. RESULTS: The new setup enabled controlled deposition of fibers in different designed orientations. The fabricated small-diameter vascular scaffolds consisted of an inner layer of longitudinally oriented fibers and an outer layer of circumferentially oriented fibers (L + C vascular scaffold). Key parameters, including rotational speed, the utilization of the auxiliary electrode, and top-to-collector distance (TCD) significantly influenced fiber orientation. Additionally, voltage, TCD, feed rate, needle size, auxiliary electrode and collector-auxiliary electrode distance affected fiber diameter and distribution. Mechanical advantages and improved surface wettability of L + C vascular scaffold were confirmed through tensile testing and water contact angle. Cellular experiments indicated that L + C vascular scaffold facilitated cell adhesion and proliferation, with human umbilical vein endothelial cells and smooth muscle cells attaching and elongating along the fiber direction of the inner and outer layer, respectively. CONCLUSION This study demonstrated the feasibility of fabricating fiber-aligned, thick-walled vascular scaffolds using a modified electrospinning setup. The findings provided insights into how the auxiliary electrode, specific collector influenced fiber deposition, potentially advancing biomimetic vascular scaffold engineering.

BACKGROUND: Tissue engineering holds promise for vascular repair and regeneration by mimicking the extracellular matrix of blood vessels. However, achieving a functional and thick vascular wall with aligned fiber architecture by electrospinning remains a significant challenge. METHODS: A novel electrospinning setup was developed that utilizes an auxiliary electrode and a spring. The impact of process parameters on fiber size and morphology was investigated. The structure and functions of the scaffolds were evaluated through material characterization and assessments of cellular biocompatibility. RESULTS: The new setup enabled controlled deposition of fibers in different designed orientations. The fabricated small-diameter vascular scaffolds consisted of an inner layer of longitudinally oriented fibers and an outer layer of circumferentially oriented fibers (L + C vascular scaffold). Key parameters, including rotational speed, the utilization of the auxiliary electrode, and top-to-collector distance (TCD) significantly influenced fiber orientation. Additionally, voltage, TCD, feed rate, needle size, auxiliary electrode and collector-auxiliary electrode distance affected fiber diameter and distribution. Mechanical advantages and improved surface wettability of L + C vascular scaffold were confirmed through tensile testing and water contact angle. Cellular experiments indicated that L + C vascular scaffold facilitated cell adhesion and proliferation, with human umbilical vein endothelial cells and smooth muscle cells attaching and elongating along the fiber direction of the inner and outer layer, respectively. CONCLUSION This study demonstrated the feasibility of fabricating fiber-aligned, thick-walled vascular scaffolds using a modified electrospinning setup. The findings provided insights into how the auxiliary electrode, specific collector influenced fiber deposition, potentially advancing biomimetic vascular scaffold engineering.

BACKGROUND: Tissue engineering holds promise for vascular repair and regeneration by mimicking the extracellular matrix of blood vessels. However, achieving a functional and thick vascular wall with aligned fiber architecture by electrospinning remains a significant challenge. METHODS: A novel electrospinning setup was developed that utilizes an auxiliary electrode and a spring. The impact of process parameters on fiber size and morphology was investigated. The structure and functions of the scaffolds were evaluated through material characterization and assessments of cellular biocompatibility. RESULTS: The new setup enabled controlled deposition of fibers in different designed orientations. The fabricated small-diameter vascular scaffolds consisted of an inner layer of longitudinally oriented fibers and an outer layer of circumferentially oriented fibers (L + C vascular scaffold). Key parameters, including rotational speed, the utilization of the auxiliary electrode, and top-to-collector distance (TCD) significantly influenced fiber orientation. Additionally, voltage, TCD, feed rate, needle size, auxiliary electrode and collector-auxiliary electrode distance affected fiber diameter and distribution. Mechanical advantages and improved surface wettability of L + C vascular scaffold were confirmed through tensile testing and water contact angle. Cellular experiments indicated that L + C vascular scaffold facilitated cell adhesion and proliferation, with human umbilical vein endothelial cells and smooth muscle cells attaching and elongating along the fiber direction of the inner and outer layer, respectively. CONCLUSION This study demonstrated the feasibility of fabricating fiber-aligned, thick-walled vascular scaffolds using a modified electrospinning setup. The findings provided insights into how the auxiliary electrode, specific collector influenced fiber deposition, potentially advancing biomimetic vascular scaffold engineering.

BACKGROUND: Tissue engineering holds promise for vascular repair and regeneration by mimicking the extracellular matrix of blood vessels. However, achieving a functional and thick vascular wall with aligned fiber architecture by electrospinning remains a significant challenge. METHODS: A novel electrospinning setup was developed that utilizes an auxiliary electrode and a spring. The impact of process parameters on fiber size and morphology was investigated. The structure and functions of the scaffolds were evaluated through material characterization and assessments of cellular biocompatibility. RESULTS: The new setup enabled controlled deposition of fibers in different designed orientations. The fabricated small-diameter vascular scaffolds consisted of an inner layer of longitudinally oriented fibers and an outer layer of circumferentially oriented fibers (L + C vascular scaffold). Key parameters, including rotational speed, the utilization of the auxiliary electrode, and top-to-collector distance (TCD) significantly influenced fiber orientation. Additionally, voltage, TCD, feed rate, needle size, auxiliary electrode and collector-auxiliary electrode distance affected fiber diameter and distribution. Mechanical advantages and improved surface wettability of L + C vascular scaffold were confirmed through tensile testing and water contact angle. Cellular experiments indicated that L + C vascular scaffold facilitated cell adhesion and proliferation, with human umbilical vein endothelial cells and smooth muscle cells attaching and elongating along the fiber direction of the inner and outer layer, respectively. CONCLUSION This study demonstrated the feasibility of fabricating fiber-aligned, thick-walled vascular scaffolds using a modified electrospinning setup. The findings provided insights into how the auxiliary electrode, specific collector influenced fiber deposition, potentially advancing biomimetic vascular scaffold engineering.

BACKGROUND: Tissue engineering holds promise for vascular repair and regeneration by mimicking the extracellular matrix of blood vessels. However, achieving a functional and thick vascular wall with aligned fiber architecture by electrospinning remains a significant challenge. METHODS: A novel electrospinning setup was developed that utilizes an auxiliary electrode and a spring. The impact of process parameters on fiber size and morphology was investigated. The structure and functions of the scaffolds were evaluated through material characterization and assessments of cellular biocompatibility. RESULTS: The new setup enabled controlled deposition of fibers in different designed orientations. The fabricated small-diameter vascular scaffolds consisted of an inner layer of longitudinally oriented fibers and an outer layer of circumferentially oriented fibers (L + C vascular scaffold). Key parameters, including rotational speed, the utilization of the auxiliary electrode, and top-to-collector distance (TCD) significantly influenced fiber orientation. Additionally, voltage, TCD, feed rate, needle size, auxiliary electrode and collector-auxiliary electrode distance affected fiber diameter and distribution. Mechanical advantages and improved surface wettability of L + C vascular scaffold were confirmed through tensile testing and water contact angle. Cellular experiments indicated that L + C vascular scaffold facilitated cell adhesion and proliferation, with human umbilical vein endothelial cells and smooth muscle cells attaching and elongating along the fiber direction of the inner and outer layer, respectively. CONCLUSION This study demonstrated the feasibility of fabricating fiber-aligned, thick-walled vascular scaffolds using a modified electrospinning setup. The findings provided insights into how the auxiliary electrode, specific collector influenced fiber deposition, potentially advancing biomimetic vascular scaffold engineering.

Objective:To report the surveillance results of the distribution and antimicrobial resistance profile of clinical isolates in Anhui province.Methods:Surveillance data from 94 members of the Anhui Antimicrobial Resistance Surveillance Network（HuiNet）from October 2023 to September 2024 were collected，the major drug-resistant bacteria and the resistance to commonly used antibiotics were analyzed. WHONET 5.6 and SPSS 25.0 software were used for data analysis.Results:Among 240 339 clinical strains，Gram-negative bacteria accounted for 75.0%（180 153 strains）. The detected bacteria mainly include Escherichia coli（ n=53 587，22.3%）， Klebsiella pneumoniae（ n=39 774，16.5%）， Pseudomonas aeruginosa（ n=25 505，10.6%）， Staphylococus aureus（ n=19 438，8.1%）， Acinetobacter baumannii complex（ n=14 239，5.9%），and so on. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococcus aureus（MRCNS）were 37.7%（7 112/18 853）and 73.9%（13 221/17 895），respectively. No vancomycin- and teicolanin-resistant Staphylococcus were detected. The prevalence of carbapenem-resistant Escherichia coli（CREC）and Klebsiella pneumoniae（CRKP）were 1.9%（971/51 991）and 12.3%（4 864/39 414），respectively. The resistance rate of CRKP to tigecycline and polycolistin B was 7.7% and 7.9%，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex and Pseudomonas aeruginosa（CRPA）were 57.9%（8 222/14 198）and 18.2%（4 569/25 052），respectively，with low resistance to polycolistin B（2.0% and 7.2%，respectively）. The detection rates of MRSA，MRCNS，CRAB complex，third-generation cephalosporin-resistant Escherichia coli（3GC-R-EC）and quinolone-resistant Escherichia coli（QREC）in northern Anhui were the highest（46.8%，77.1%，65.6%，57.6% and 55.5%，respectively），which were higher than those in central and southern Anhui（ χ2=107.858 and 566.202，5.950 and 142.223，39.254 and 289.137，135.402 and 449.114，39.142 and 185.114， P<0.05 or <0.01），and the detection rates in central Anhui were higher than those in southern Anhui（ χ2=272.031，102.717，162.409，118.891 and 66.889，all P<0.001）. The detection rates of CRKP，CRPA and thirdgeneration cephalosporinresistant Klebsiella pneumoniae（3GC-R-KP）in central Anhui were the highest（16.7%，21.7% and 32.0%，respectively），which were higher than those in northern and southern Anhui（ χ2=229.656 and 439.377，156.599 and 65.818，77.386 and 232.568，all P<0.001）. The detection rates of CREC，3GC-R-EC and QREC were the highest in the elderly（2.2%，54.0% and 56.4%，respectively），which were higher than those in children and adults（ χ2=8.034 and 13.150，17.032 and 103.437，438.353 and 183.099，all P<0.01）. The detection rates of CRKP and 3GC-R-KP in neonates were the highest（20.6% and 56.9%，respectively），which were significantly higher than those in children，adults and the elderly（ χ2=38.869，8.337 and 7.921；65.517，55.525 and 49.214，all P<0.01），and the detection rate of 3GC-R-KP in the elderly was higher than that in children and adults（ χ2=14.122 and 7.501，both P<0.01）. The detection rates of CRAB complex，CRPA，CREC，CRKP and 3GC-R-KP in tertiary hospitals were higher than those in secondary hospitals（ χ2=25.606，16.501，5.820，33.116 and 117.086， P<0.05 or <0.01）. Except for MRSA，vancomycin-resistant Enterococcus faecium and QREC，the detection rates of major drug-resistant bacteria in intensive care unit（ICU）were the highest（all P<0.001）. From 2019 to 2024，the detection rates of MRSA，MRCNS，CRKP，CRAB complex and CRPA all showed a slow decreasing trend（ χ2=42.319，122.779，340.381，83.512 and 81.668，all P<0.001）. Conclusions:The situation of antimicrobial resistance in Anhui province shows a downward trend，but it is still serious，especially in northern and central Anhui. It is necessary to pay attention to the bacterial resistance particularly for the elderly，newborns，children and ICU.