To explore the absorption mechanism of APS-Ⅱ in vivo by establishing M cell model. First, Astragalus polysaccharides (APS) was divided into two different molecular weight polysaccharides APS-I ( > 2 000 kDa) and APS-II (10 kDa) by ultrafiltration, and APS-II (10 kDa) was prepared and fluorescently labeled. Meanwhile, M cell model was constructed by Caco-2 cells and Raji cells. The M cell model was treated with transport inhibitors to explore the transport of APS-Ⅱ on M cells. The results show that FITC has been successfully labeled to the end of APS-Ⅱ, and the M cell model was successfully constructed, which found that APS-Ⅱ could be transported by M cells, and four transport inhibitors of 5-(N-ethyl-N-isopropyl) amiloride (EIPA), genistein, dynasore and nocodazole indicated that APS-II may enter cells through clathrin and caveolin-mediated endocytosis.

Bacterial biofilms(BF)are complex microbial communities formed by bacteria on living or abiotic surfaces.Their formation significantly enhances bacterial virulence and drug resistance and is associated with a high proportion of chronic bacterial infections,posing a serious threat to human health.The ability of traditional antibiotics and commonly used disinfectants to clear biofilms is limited,and an effective new strategy to treat BF is urgently needed.Bacteriophage,as a kind of virus that can infect and lyse bacteria,has high safety and specificity,and is considered as a promising alternative method for the treatment of BF.In this paper,the mechanism of bacteriophage anti-bacterial biofilm and the application strategies based on bacteriophage and its derivatives in the prevention and control of bacteriophage biofilm formation were reviewed,which provided new ideas for the development of efficient bacteriophage anti-bacterial biofilm methods.

Objective·To reveal the direction,efficiency,and mechanical load of single tooth displacement with clear aligners for expansion treatment during the transitional dentition period with the aid of finite element analysis.Additionally,overcorrection and torque compensation systems were designed to address insufficient expansion efficiency and buccal inclination of posterior teeth.Methods·One volunteer in mixed dentition period was included to construct a three dimentional cranio-maxillary complex model and an invisible orthodontic system,simulating the buccal displacement(load 1?4:0.200,0.275,0.300,0.325 mm,respectively)and root buccal torque(load 1:buccal displacement load 0.200 mm,root buccal torque 0°;load 5:buccal displacement load 0.275 mm,root buccal torque 1.0°;load 6:buccal displacement load 0.300 mm,root buccal torque 1.3° and load 7:buccal displacement load 0.325mm,root buccal torque 1.8°)on the maxillary deciduous teeth to the first permanent molar with a non bracket invisible orthodontic appliance.Through finite element analysis,the tooth displacement and equivalent stress distribution of the periodontal membrane can be calculated.Results·Expansion treatment with clear aligners in the transitional dentition phase primarily revealed the effect of buccal expansion of teeth;different teeth achieved different levels of expansion rate.At a set expansion amount of 0.200 mm per side,expansion efficiency in the maxillary first permanent molar was 51.86%,second primary molar 68.76%,first primary molar 73.48%,and primary cuspid 84.17%.By designing over-correction(0.275,0.300,0.325 mm),the results showed significant enhancement in expansion effect.When overcorrection length reached 150%(0.300 mm),expansion efficiency at the maxillary first permanent molar,second primary molar,first primary molar,and primary cuspid were 75.16%,99.96%,107.35%,and 122.37%,respectively.The expansion efficiency of maxillary second primary molar,first primary molar,and primary cuspid was close to 100.00%.The overcorrection design exacerbated the dental effects of expansion,intensifying the tendency for teeth to tilt toward the cheek side,leading to side effects such as buccal inclination and drooping of the palatal cusps.When the overcorrection amount for expansion reached 150%,the crown-root displacement in the upper first permanent molar,second primary molar,first primary molar,and primary cuspid were-0.109,-0.134,-0.132,and-0.298 mm,respectively.Applying specific torque compensation for different tooth positions can combat the buccal inclination of posterior teeth.At an overcorrection length of 150%(0.300 mm)with an added 1.3° root buccal torque,expansion efficiency was 56.15%,73.88%,79.49%,and 87.80%,respectively.While the crown-root displacement differences reduced to-0.081,-0.097,-0.095,and-0.208 mm.Conclusion·When using clear aligners for expansion treatment during a transitional dentition period,side effects such as buccal inclination of posterior teeth exist.Furthermore,various teeth realize differing levels of expansion efficiency,necessitating the design of unique adjustment strategies according to different tooth positions.Overcorrection can improve expansion efficiency but needs to be coordinated with root buccal torque for the whole tooth to move buccally.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Klebsiella strains in 52 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Antimicrobial susceptibility testing was carried out according to the unified CHINET protocol.The susceptibility results were interpreted according to the breakpoints in the Clinical & Laboratory Standards Institute(CLSI)M100 document.Results A total of 241,549 nonduplicate Klebsiella strains were isolated from 2015 to 2021,including Klebsiella pneumoniae(88.0％),Klebsiella aerogenes(5.8％),Klebsiella oxytoca(5.7％),and other Klebsiella species(0.6％).Klebsiella strains were mainly isolated from respiratory tract(48.49±5.32)％.Internal medicine(22.79±3.28)％,surgery(17.98±3.10)％,and ICU(14.03±1.39)％were the top 3 departments where Klebsiella strains were most frequently isolated.K.pneumoniae isolates showed higher resistance rate to most antimicrobial agents compared to other Klebsiella species.Klebsiella isolates maintained low resistance rates to tigecycline and polymyxin B.ESBLs-producing K.pneumoniae and K.oxytoca strains showed higher resistance rates to all the antimicrobial agents tested compared to the corresponding ESBLs-nonproducing strains.The K.pneumoniae and carbapenem-resistant K.pneumoniae(CRKP)strains isolated from ICU patients demonstrated higher resistance rates to majority of the antimicrobial agents tested than the strains isolated from non-ICU patients.The CRKP strains isolated from adult patients had higher resistance rates to most of the antimicrobial agents tested than the corresponding CRKP strains isolated from paediatric patients.Conclusions The prevalence of carbapenem-resistant strains in Klebsiella isolates increased greatly from 2015 to 2021.However,the Klebsiella isolates remained highly susceptible to tigecycline and polymyxin B.Antimicrobial resistance surveillance should still be strengthened for Klebsiella strains.

Objective To investigate the changing distribution and antibiotic resistance profiles of clinical isolates of Staphylococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Staphylococcus according to the unified protocol of CHINET(China Antimicrobial Surveillance Network)using disk diffusion method and commercial automated systems.The CHINET antimicrobial resistance surveillance data from 2015 to 2021 were interpreted according to the 2021 CLSI breakpoints and analyzed using WHONET 5.6.Results During the period from 2015 to 2021,a total of 204,771 nonduplicate strains of Staphylococcus were isolated,including 136,731(66.8％)strains of Staphylococcus aureus and 68,040(33.2％)strains of coagulase-negative Staphylococcus(CNS).The proportions of S.aureus isolates and CNS isolates did not show significant change.S.aureus strains were mainly isolated from respiratory specimens(38.9±5.1)％,wound,pus and secretions(33.6±4.2)％,and blood(11.9±1.5)％.The CNS strains were predominantly isolated from blood(73.6±4.2)％,cerebrospinal fluid(12.1±2.5)％,and pleural effusion and ascites(8.4±2.1)％.S.aureus strains were mainly isolated from the patients in ICU(17.0±7.3)％,outpatient and emergency(11.6±1.7)％,and department of surgery(11.2±0.9)％,whereas CNS strains were primarily isolated from the patients in ICU(32.2±9.7)％,outpatient and emergency(12.8±4.7)％,and department of internal medicine(11.2±1.9)％.The prevalence of methicillin-resistant strains was 32.9％in S.aureus(MRSA)and 74.1％in CNS(MRCNS).Over the 7-year period,the prevalence of MRSA decreased from 42.1％to 29.2％,and the prevalence of MRCNS decreased from 82.1％to 68.2％.MRSA showed higher resistance rates to all the antimicrobial agents tested except trimethoprim-sulfamethoxazole than methicillin-susceptible S.aureus(MSSA).Over the 7-year period,MRSA strains showed decreasing resistance rates to gentamicin,rifampicin,and levofloxacin,MRCNS showed decreasing resistance rates to gentamicin,erythromycin,rifampicin,and trimethoprim-sulfamethoxazole,but increasing resistance rate to levofloxacin.No vancomycin-resistant strains were detected.The prevalence of linezolid-resistant MRCNS increased from 0.2％to 2.3％over the 7-year period.Conclusions Staphylococcus remains the major pathogen among gram-positive bacteria.MRSA and MRCNS were still the principal antibiotic-resistant gram-positive bacteria.No S.aureus isolates were found resistant to vancomycin or linezolid,but linezolid-resistant strains have been detected in MRCNS isolates,which is an issue of concern.

The mucous barrier is a major physiological obstacle that the mucosal drug delivery system needs to deal with. In response to this physiological barrier, many achievements have been made in research of mucosal adhesion and mucus penetration. This review puts emphasis on the progress of the research on new mucosal adhesion strategies such as cationization, sulfhydrylization, maleimide functionalization, lectinization and catechol conjugation; polyethylene glycol (PEG), polyvinyl alcohol (PVA), poly (2-alkyl-2-oxazoline) (POZ), zwitterionic polymers and other mucus-inert materials, strategies to enhance mucus penetration ability such as enzyme functionalization, reducing agent pretreatment and so on. The problems of each strategy are also analyzed and discussed, which can provide some references for clinical transformation.

The water-soluble polypeptide drug oxytocin was encapsulated in liposomes by reverse-phase evaporation vesicle method to obtain oxytocin loaded liposomes (OT@LPs) which was further modified with cationic cell penetrating peptide—arginine octamer (R8) to get R8 modified oxytocin loaded liposomes (OT@LPs-R8) which showed enhanced mucoadhesive. The brain targeting efficiency was evaluated preliminarily after nasal administration. OT@LPs-R8 showed a round shape with a particle size distribution of 110.2 ± 7.3 nm, a surface potential as high as +18 mV, a drug loading (62.17 ± 1.88) %, an encapsulation rate (5.85 ± 0.72) %, and stood stable in nasal mucus. After nasal administration, it could significantly prolong the retention and enhance the distribution in the brain with no irritation to the nasal mucosa. The animal experiment in line with the regulations of the Department of Laboratory Animal Science of Fudan University on the ethics of animal experiments had been carried out after passing the review of the Animal Ethics Committee of Fudan University. The results showed nasal administration of OT@LPs-R8 could promote oxytocin directly into the brain from the nose which expected to become a new carrier for delivery of oxytocin to the brain.