BACKGROUND:Magnetic nanomaterials have biological activities such as promoting osteogenic differentiation of stem cells and inhibiting osteoclast formation,and can effectively promote the healing of injured bone tissue under the synergistic effect of magnetic fields.They have a very broad application prospect in bone injury repair. OBJECTIVE:To review the mechanism of magnetic nanomaterials and magnetic fields promoting bone repair,as well as their research progress in the field of bone injury repair. METHODS:Relevant literature search was conducted in PubMed and Web of Science databases with the search terms"magnetic nanomaterials,magnetic field,bone repair,bone tissue engineering,stem cell,osteoblast,osteoclast."The time limit of literature search was from 2003 to 2023,which was screened and analyzed.Some classic articles were manually retrieved,and 98 articles were finally included for analysis. RESULTS AND CONCLUSION:(1)Magnetic nanomaterials have biological effects such as promoting osteoblast differentiation,inhibiting osteoclast formation and regulating the immune microenvironment.In addition,magnetic nanomaterials can regulate the physicochemical properties of tissue engineering scaffolds,such as mechanical properties and surface morphology,and endowed with magnetic properties,which is conducive to the regulation of the adhesion,proliferation and osteogenic differentiation of stem cells.(2)The magnetic field has the ability to regulate multiple cell signaling pathways to promote osteoblast differentiation,inhibit osteoclast formation,stimulate angiogenesis and other biological effects,thus accelerating the healing of damaged bone tissue.(3)The joint application of magnetic nanomaterials and magnetic field accelerates the repair of bone damage by activating mechanotransduction,increasing the content of intracellular magnetic nanoparticles,and enhancing the effect of micro-magnetic field,which provides a new idea for the research of bone tissue engineering.(4)Magnetic field has demonstrated definite efficacy in the treatment of clinical fractures,osteoporosis,and osteoarthritis diseases,which is beneficial for bone tissue growth,reducing bone loss,alleviating pain,and improving the quality of life of patients.(5)Magnetic nanomaterials and magnetic fields have great potential for application in bone damage repair and regeneration,but the interaction mechanism between magnetic nanomaterials,magnetic fields,and cells has not been fully elucidated.Moreover,the key parameters of magnetic fields that regulate intracellular molecular events,including the type,intensity,frequency,duration,and mode of the magnetic field,as well as the precise biological effects of a specific magnetic field on osteoblasts and the underlying mechanisms,have yet to be defined.(6)Further attention needs to be paid to the effects on osteoclasts,nerves,blood vessels,and immune cells in the microenvironment of damaged tissues.Finally,the safety of magnetic materials for human use is yet to be systematically studied in terms of their distribution,metabolism,and acute and chronic toxicities.

Objective To examine the safety, efficacy and durability of totally endoscopic minimally invasive (TEMI) mitral valve repair in Barlow’s disease (BD). Methods A retrospective study was performed on patients who underwent mitral valve repair for BD from January 2010 to June 2021 in the Guangdong Provincial People’s Hospital. The patients were divided into a MS group and a TEMI group according to the surgery approaches. A comparison of the clinical data between the two groups was conducted. Results A total of 196 patients were enrolled, including 133 males and 63 females aged (43.8±14.9) years. There were 103 patients in the MS group and 93 patients in the TEMI group. No hospital death was observed. There was a higher percentage of artificial chordae implantation in the TEMI group compared to the MS group (P=0.020), but there was no statistical difference between the two groups in the other repair techniques (P>0.05). Although the total operation time between the two groups was not statistically different (P=0.265), the TEMI group had longer cardiopulmonary bypass time (P<0.001) and aortic clamp time (P<0.001), and shorter mechanical ventilation time (P<0.001) and postoperative hospitalization time (P<0.001). No statistical difference between the two groups in the adverse perioperative complications (P>0.05). The follow-up rate was 94.2% (180/191) with a mean time of 0.2-12.4 (4.0±2.4) years. Two patients in the MS group died with non-cardiac reasons during the follow-up period. The 3-year, 5-year and 10-year overall survival rates of all patients were 100.0%, 99.2%, 99.2%, respectively. Compared with the MS group, there was no statistical difference in the survival rate, recurrence rate of mitral regurgitation, reoperation rate of mitral valve or adverse cardiovascular and cerebrovascular events in the TEMI group (P＞0.05). Conclusion TEMI approach is a safe, feasible and effective approach for BD with a satisfying long-term efficacy.

Fluorescence anisotropy(FA)analysis has many advantages such as no requirement of separation,high throughput and real-time detection,and thus has been widely used in many fields,including biochemical analysis,food safety detection,environmental monitoring,etc.However,due to the small volume or mass of the target,its combination with the fluorescence probe cannot produce significant signal change.To solve this issue,researchers often use nanomaterials to enhance the mass or volume of fluorophore to improve the sensitivity.Nevertheless,this FA amplification strategy also has some disadvantages.Firstly,nanomaterials are easy to quench fluorescence.As a result,the FA value is easily influenced by light scattering,which reduces the detection accuracy.Secondly,fluorescent probes in most methods require complex modification steps.Therefore,it is necessary to develop new FA probes that do not require the amplification of volume and mass or modification.As a new kind of nanomaterials,luminescent metal-organic framework(MOF)has a large volume(or mass)and strong fluorescence emission.It does not require additional signal amplification materials.As a consequence,it can be used as a potential FA probe.This study successfully synthesized a lanthanide metal organic framework(Ce-TCPP MOF)using cerium ion(Ce3+)as the central ion and 5,10,15,20-tetra(4-carboxylphenyl)porphyrin(H2TCPP)as the ligand through microwave assisted method,and used it as a novel unmodified FA probe to detect phosphate ions(Pi).In the absence of Pi,Ce-TCPP MOF had a significant FA value(r).After addition of Pi,Pi reacted with Ce3+in MOF and destroyed the structure of MOF into the small pieces,resulting in a decrease in r.The experimental results indicated that with the increase of Pi concentration,the change of the r of Ce-TCPP MOF(Δr)gradually increased.The Δr and Pi concentration showed a good linear relationship within the range of 0.5-3.5 μmol/L(0.016-0.108 mg/L).The limit of detection(LOD,3σ/k)was 0.41 μmol/L.The concentration of Pi in the Jialing River water detected by this method was about 0.078 mg/L,and the Pi value detected by ammonium molybdate spectrophotometry was about 0.080 mg/L.The two detection results were consistent with each other,and the detection results also meet the ClassⅡwater quality standard,proving that this method could be used for the detection of Pi in complex water bodies.

Objective To research the procedure for creating an animal model of mitral regurgitation by implanting a device through the apical artificial chordae tendineae, and to assess the stability and dependability of the device. Methods Twelve large white swines were employed in the experiments. Through a tiny hole in the apex of the heart, the artificial chordae tendineae of the mitral valve was inserted under the guidance of transcardiac ultrasonography. Before, immediately after, and one and three months after surgery, cardiac ultrasonography signs were noted. Results All models were successfully established. During the operation and the follow-up, no swines died. Immediately after surgery, the mitral valve experienced moderate regurgitation. Compared with preoperation, there was a variable increase in the amount of regurgitation and the values of heart diameters at a 3-month follow-up (P<0.05). Conclusion In off-pump, the technique of pulling the mitral valve leaflets with chordae tendineae implanted transapically under ultrasound guidance can stably and consistently create an animal model of mitral regurgitation.

BACKGROUND:Hydrogel microparticles,due to their porous and injectable properties,have demonstrated unique advantages in biomedical fields,such as the delivery of cells and bioactive factors/drugs,the construction of tissue repair scaffolds.They have broad application prospects. OBJECTIVE:To review the latest research progress and discuss the key problems and challenges in the research of bone tissue engineering based on hydrogel microparticles. METHODS:The relevant articles in PubMed and CNKI were searched by computer.The English key words were"hydrogels,microparticles,microspheres,microcarriers,bone,bone defect,bone repair,bone healing,bone tissue engineering"while the Chinese key words were"hydrogels,microparticles,microspheres,bone tissue engineering,bone defect,bone repair,bone regeneration".The retrieval period was from 2002 to 2022,and 127 articles were finally included for review. RESULTS AND CONCLUSION:(1)At present,various hydrogel microparticles have been developed for use in bone tissue engineering strategies,for example,hydrogel microparticles carrying cells or bioactive factors/drugs,hydrogel microparticles as biological scaffolds,stimulus-responsive hydrogel microparticles,biomineralized hydrogel microparticles,hydrogel microparticles combined with other biological materials.(2)Bone tissue engineering repair strategies based on hydrogel microparticles mainly regulate bone repair by promoting stem cell recruitment and osteogenic differentiation,regulating the local inflammatory microenvironment and promoting angiogenesis at the site of injury.However,the present studies did not deeply explore the effect of bone tissue engineering based on hydrogel microparticles on the recruitment and differentiation of endogenous stem cells and the regulation of the inflammatory microenvironment by the physical and chemical properties of hydrogel microparticles.The long-term in vivo adverse reactions of hydrogel microparticles have not been explored yet,and it is difficult to mass-produce them,thus future research needs to strengthen the mechanism exploration and technical route,so as to provide a reasonable reference for the development of hydrogel microparticles that can be used for clinical transformation.

Objective To investigate the infection status and changing trend of hepatitis C virus(HCV)infection in hospitalized patients in medical institutions,and provide reference for formulating HCV infection prevention and control strategies.Methods HCV infection surveillance results from cross-sectional survey data reported to China Healthcare-associated Infection(HAI)Surveillance System in 2020 were summarized and analyzed,HCV positive was serum anti-HCV positive or HCV RNA positive,survey result was compared with the survey results from 2003.Results In 2020,1 071 368 inpatients in 1 573 hospitals were surveyed,738 535 of whom underwent HCV test,4 014 patients were infected with HCV,with a detection rate of 68.93％and a HCV positive rate of 0.54％.The positive rate of HCV in male and female patients were 0.60％and 0.48％,respectively,with a statistically sig-nificant difference(x2=47.18,P＜0.001).The HCV positive rate in the 50-＜60 age group was the highest(0.76％),followed by the 40-＜50 age group(0.71％).Difference among all age groups was statistically signifi-cant(x2=696.74,P＜0.001).In 2003,91 113 inpatients were surveyed.35 145 of whom underwent HCV test,resulting in a detection rate of 38.57％;775 patients were infected with HCV,with a positive rate of 2.21％.In 2020,HCV positive rates in hospitals of different scales were 0.46％-0.63％,with the highest in hospital with bed numbers ranging 600-899.Patients'HCV positive rates in hospitals of different scales was statistically signifi-cant(X2=35.34,P＜0.001).In 2020,12 provinces/municipalities had over 10 000 patients underwent HCV-rela-ted test,and HCV positive rates ranged 0.19％-0.81％,with the highest rate from Hainan Province.HCV posi-tive rates in different departments were 0.06％-0.82％,with the lowest positive rate in the department of pedia-trics and the highest in the department of internal medicine.In 2003 and 2020,HCV positive rates in the depart-ment of infectious diseases were the highest,being 7.95％and 3.48％,respectively.Followed by departments of orthopedics(7.72％),gastroenterology(3.77％),nephrology(3.57％)and general intensive care unit(ICU,3.10％)in 2003,as well as departments of gastroenterology(1.35％),nephrology(1.18％),endocrinology(0.91％),and general intensive care unit(ICU,0.79％)in 2020.Conclusion Compared with 2003,HCV positive rate decreased significantly in 2020.HCV infected patients were mainly from the department of infectious diseases,followed by departments of gastroenterology,nephrology and general ICU.HCV infection positive rate varies with gender,age,and region.

Objective To observe the effect of multi-modal hand hygiene(HH)intervention on HH compliance,as well as the relationship between HH compliance and the healthcare-associated(HA)case infection incidence.Methods From 2014 to 2022,the infection control team in a tertiary first-class hospital implemented multi-modal HH intervention for health care workers(HCWs).The changing trend of HH monitoring data,the correlation be-tween HH compliance rate and HA case infection incidence were analyzed retrospectively.Results The consump-tion of HH products in the wards showed a stable upward trend;HH compliance rate increased from 64.98％in 2014 to 85.01％in 2022(P＜0.001),and HA case infection incidence decreased from 1.21％to 0.83％(P＜0.05).HH compliance rate was negatively correlated with HA case infection incidence(r=-0.369,P=0.027).HH compliance rates in different regions and job posts in each quarter were increased(P＜0.001).For 5 different HH moments in each quarter,HH compliance rate fluctuated slightly before sterile manipulation and after touching patient;presented rising trend after touching surroundings around patient,and decreased before touching patient and after touching patient's body fluid since 2020(P＜0.001).Conclusion Multi-modal HH intervention can im-prove the HH compliance of HCWs,improving their HH awareness is conducive to reducing HA case infection incidence.

Objective To investigate the biological function and main molecular mechanism of long noncoding RNA RMRP(lncRNA RMRP)in endometrial carcinoma.Methods The specimens of carcinoma tissues and adjacent tissues of 30 patients with endometrial carcinoma who received surgical treatment in our hospital were collected.RT-qPCR was used to detect the expression of lncRNA RMRP in endometrial carcinoma tissues and adjacent tissues,and HESC cells and HEC-1-A cells.The endometrial carcinoma cell line HEC-1-A was cultured in vitro,and the Vector,pcDNA-RMRP,NC-siRNA,RMRP-siRNA,NC mimic,miR-580-3p mimic,pcDNA-RMRP+NC mimic,pcDNA-RMRP+ miR-580-3p mimic,RMRP-siRNA+Vector,RMRP-siRNA+pcDNA-JAK2,NC inhibitor,and miR-580-3p inhibitor were transfected into HEC-1-A cells as the Vector group,the pcDNA-RMRP group,the NC-siRNA group,the RMRP-siRNA group,the NC mimic group,the miR-580-3p mimic group,the pcDNA-RMRP+NC mimic group,the pcDNA-RMRP+miR-580-3p mimic group,the RMRP siRNA+Vector group,the RMRP-siRNA+pcDNA-JAK2 group,the NC inhibitor group,and the miR-580-3p inhibitor group respectively.RT-qPCR was used to detect the expression of lncRNA RMRP and miR-580-3p in cells.CCK-8 was used to detect cell proliferation rate.The apoptosis rate was detected by flow cytometry analysis.Bioinformatics software and dual luciferase reporter gene experiment were used to predict and verify the targeted relationships between miR-580-3p and lncRNA RMRP,as well as miR-580-3p and JAK2.Western blot was used to detect the protein expression of JAK/STAT signaling pathway.Results Compared with adjacent tissues,lncRNA RMRP was highly expressed in endometrial carcinoma tissues(P<0.05).Compared with HESC cells,the expression of lncRNA RMRP in HEC-1-A cells was significantly increased(P<0.05).pcDNA-RMRP significantly promoted cell proliferation and inhibited cell apoptosis,while RMRP-siRNA significantly inhibited cell proliferation and promoted cell apoptosis,with statistically significant diferences(P<0.05).miR-580-3p was the downstream target miRNA of lncRNA RMRP,and lncRNA RMRP could negatively regulate the expression of miR-580-3p.JAK2 was the downstream target gene of miR-580-3p,and miR-580-3p could negatively regulate the expression of JAK2 protein.pcDNA-RMRP significantly increased the protein levels of JAK2,p-JAK2 and p-STAT3 in the cells,while co-transfection of pcDNA-RMRP and miR-580-3p mimic significantly decreased the protein levels of JAK2,p-JAK2 and p-STAT3,with statistically significant diferences(P<0.05).RMRP-siRNA could signifi-cantly reduce the protein levels of JAK2,p-JAK2 and p-STAT3 in cells.After co-transfection of RMRP-siRNA and pcDNA-JAK2,the protein levels of JAK2,p-JAK2 and p-STAT3 were significantly increased,with statistically significant diferences(P<0.05).In addition,co-transfection of RMRP-siRNA and pcDNA-JAK2 increased cell proliferation and decreased cell apoptosis,with statistically significant diferences(P<0.05).Conclusion Knockdown of lncRNA RMRP could inhibit endometrial carcinoma cell proliferation and promote cell apoptosis by regulating JAK2/STAT3 signaling pathway,which might be a potential therapeutic target for endometrial carcinoma.

ObjectiveTo present the exploration and application of a prospective follow-up research method for acute infectious disease surveillance based on natural community populations， using COVID-19 infection as an example， and to provide a reference for improving the infectious disease surveillance and early warning system. MethodsA multi-stage probability proportional sampling method was employed to sample residents from all communities of 16 administrative districts in Shanghai， with households as the units. A cohort for acute infectious diseases based on natural community populations was established. The baseline survey was conducted for all cohort subjects， and COVID-19 antigen test kits were distributed. From December 21， 2022 to September 30， 2023， prospective follow-up monitoring of COVID-19 antigen and nucleic acid was carried out on the study subjects on a weekly basis. The baseline characteristics and follow-up information of the cohort subjects were described. ResultsThe cohort for acute infectious diseases included a total of 12 881 subjects， comprising 6 098 males （47.3%） and 6 783 females （52.7%）. The baseline survey revealed that 35.2% （4 540/12 881） of the subjects had a history of COVID-19 infection. During the follow-up period from December 21， 2022 to September 30， 2023， the average incidence density in the cohort was 0.61/person-year， with a higher incidence density in females （0.63/person-year） compared to males （0.59/person-year）. Individuals aged 60 and above （0.64/person-year） and those with underlying health conditions （0.67/person-year） had a higher incidence density. Healthcare workers showed a notably higher incidence density （0.84/person-year） than that in other occupational groups. As of September 30， 2023， a total of 340 subjects in the cohort experienced secondary infections， with a median interval of 170 days between the first and second infections. ConclusionThis study applies cohort study method to acute infectious disease surveillance， providing crucial data support for estimating infection rates and forecasting alerts for acute infectious diseases in the community. This method can be promoted and applied as a new approach for acute infectious disease surveillance.

Objective To observe the effects of matrine on the proliferation,migration,and invasion of human neuroblastoma cells,and to investigate its potential mechanism.Methods This study was divided into AS experimental group(SK-N-AS cells treated with IC50 concentration of matrine),AS blank group(SK-N-AS cells cultured under normal conditions),AS control group(SK-N-AS cells treated with an equal amount of dimethyl sulfoxide),DZ experimental group(SK-N-DZ cells treated with IC50 concentration of matrine),DZ blank group(SK-N-DZ cells cultured under normal conditions),and DZ control group(SK-N-DZ cells treated with an equal amount of dimethyl sulfoxide).Scratch assay and Transwell chamber were used to measure the effect of matrine on the migration and invasion.The expression of E-cadherin,N-cadherin and Vimentin were tested by Western blot.Results After different intervention,the migration percentages of AS blank group,AS control group,AS experimental group,DZ blank group,DZ control group and DZ experimental group were(66.32±3.12)％,(65.27±3.44)％,(23.73±0.79)％,(46.25±4.68)％,(44.15±5.60)％and(16.77±3.52)％,respectively;the number of invasive cells were 870.45±19.32,865.32±23.39,492.74±16.81,1 198.10±43.71,1 203.03±71.91 and 891.69±42.62,respectively;the expression levels of E-cadherin protein were(100.00±11.72)％,(105.65±13.11)％,(477.20±29.71)％,(100.00±12.54)％,(97.78±12.77)％and(240.53±12.23)％,respectively;the expression levels of N-cadherin protein were(100.00±15.44)％,(103.90±10.76)％,(43.52±9.96)％,(100.00±10.12)％,(104.95±10.49)％and(38.39±8.70)％,respectively;Vimentin protein expression levels were(100.00±9.51)％,(97.39±11.33)％,(59.13±10.25)％,(100.00±13.20)％,(96.27±11.01)％and(47.67±9.48)％,respectively.There were statistically significant differences in the above indexes between the AS group and the AS blank group(P＜0.01,P＜0.001),and there were statistically significant differences between the above indexes in the DZ group and the DZ blank group(P＜0.01,P＜0.001).Conclusion Matrine inhibits the proliferation,migration,and invasion of neuroblastoma SK-N-AS and SK-N-DZ cells,potentially through suppressing epithelial-mesenchymal transition.