Objective To obtain the recombinant Argonaute protein(TtAgo)from Thermus thermophilus using gene cloning and pro-tein purification techniques and detect its endonuclease activity against the KRAS 12D mutation in vitro,thereby to provide experimental evidence for its subsequent application in the detection of gene mutations.Methods The TtAgo gene sequence was amplified from the genome of Thermus thermophilus by the PCR technology.Then,the amplified sequence was inserted into the prokaryotic expression vec-tor pET-28a to construct the recombinant vector pET-28a-TtAgo.After the recombinant TtAgo protein was induced to be expressed,it was purified sequentially by the nickel ion affinity chromatography(Ni-NTA),heparin affinity chromatography,and size-exclusion chromatography.The high-specificity nuclease activity of the recombinant TtAgo protein mediated by a short DNA guide strand(gDNA)was verified in vitro.Results The prokaryotic expression vector pET-28a-TtAgo was successfully constructed by the gene cloning tech-nique,and the soluble expression of the recombinant TtAgo protein was achieved.With the help of protein purification technology,the high-purity recombinant TtAgo protein was obtained.Under the mediation of gDNA,the recombinant TtAgo protein could specifically cleave wild-type single-stranded DNA(ssDNA),double-stranded DNA(dsDNA),and RNA molecules,while had no cleavage activi-ty for tumor KRAS 12D mutant molecules.Conclusion The high-purity recombinant TtAgo protein with nuclease activity is successful-ly obtained,and its targeted cleavage activity towards the KRAS 12D mutation site is detected in vitro.

Objective To obtain the recombinant Argonaute protein(TtAgo)from Thermus thermophilus using gene cloning and pro-tein purification techniques and detect its endonuclease activity against the KRAS 12D mutation in vitro,thereby to provide experimental evidence for its subsequent application in the detection of gene mutations.Methods The TtAgo gene sequence was amplified from the genome of Thermus thermophilus by the PCR technology.Then,the amplified sequence was inserted into the prokaryotic expression vec-tor pET-28a to construct the recombinant vector pET-28a-TtAgo.After the recombinant TtAgo protein was induced to be expressed,it was purified sequentially by the nickel ion affinity chromatography(Ni-NTA),heparin affinity chromatography,and size-exclusion chromatography.The high-specificity nuclease activity of the recombinant TtAgo protein mediated by a short DNA guide strand(gDNA)was verified in vitro.Results The prokaryotic expression vector pET-28a-TtAgo was successfully constructed by the gene cloning tech-nique,and the soluble expression of the recombinant TtAgo protein was achieved.With the help of protein purification technology,the high-purity recombinant TtAgo protein was obtained.Under the mediation of gDNA,the recombinant TtAgo protein could specifically cleave wild-type single-stranded DNA(ssDNA),double-stranded DNA(dsDNA),and RNA molecules,while had no cleavage activi-ty for tumor KRAS 12D mutant molecules.Conclusion The high-purity recombinant TtAgo protein with nuclease activity is successful-ly obtained,and its targeted cleavage activity towards the KRAS 12D mutation site is detected in vitro.

OBJECTIVE T o understand the resistance capability of berberine combined with levofloxacin in vitro to methicillin-resistant Staphylococcus aureus(MRSA).METHODS Totally 100 strains of MRSA were isolated from Shanghai Eighth People's Hospital from Jul.2023 to Jun.2024,the minimum inhibitory concentrations(MICs)of berberine and levofloxacin against the strains were determined by microbroth dilution method.The anti-bacterial effect of the combined use of the two drugs on MRSA was observed.The effects of the single and com-bined use of berberine and levofloxacin on sterilization of MRSA standard strain USA 300-LAC and their influence on cellular morphology were observed.The influence of berberine on mRNA levels of drug resistance genes and ef-flux pump-related genes in the standard strain USA 300-LAC and clinical strains was determined by means of real-time fluorescent quantitative PCR.RESULTS Among the 100 clinical isolates of MRSA,most of them were isola-ted from respiratory tract specimens of respiratory medicine department and geriatrics department,and 75.00％of the strains were resistant to levofloxacin.The MICs of both berberine and levofloxacin against the standard strain USA300-LAC were 128 μg/ml;the MICs against the clinical MRSA isolates were 64 to 1024 μg/ml and 0.125 to 256 μg/ml,respectively.Berberine combined with levofloxacin showed additive effect on 17(44.74％)strains of MRSA.The combined use of the two drugs showed the most remarkable in vitro antibacterial effect.The cellular structures of the strains were unclear and the contents of bacterial bodies increased when berberine and levofloxacin were used in combination.Berberine showed various degree of inhibitory effect on gyrA,gyrB,grlA and nor A genes.CONCLUSIONS Berberine is capable of resisting the MRSA and shows synergistic or additive effect with levofloxacin.The combined use of the two drugs may reduce the MIC against levofloxacin,destroy the morpholog-ical structure,and inhibit the expression of gyrA,gyrB,grlA and nor A genes.

OBJECTIVE To explore the effect and potential mechanisms of berberine on formation of biofilms of clinical methicillin-resistant Staphylococcus aureus(MRSA)isolates.METHODS Totally 95 clinical MRSA iso-lates were collected from Shanghai Eighth People's Hospital from Jan.2023 to Dec.2023.The 14 biofilm forma-tion-related genes in the strains were detected by polymerase chain reaction(PCR)and multiplex PCR,the mini-mum inhibitory concentration(MIC)of berberine was determined by microbroth dilution method,the effect of berberine on resistance of biofilm formation was evaluated by crustal violet staining,fluorescence microscope,Congo red agar plate and extracelluar DNA(eDNA).The transcription levels of 9 biofilm formation-related genes were detected by real-time fluorescent quantitative reverse transcription PCR.RESULTS All of the 95 strains of MRSA carried eno,clfA,clfB and icaA genes,the most widespread gene profile was bbp-eno-ebpS-fnbA-fib-clfA-clfB-icaA-sasG,and 29 strains had the phenotypes with strong capability of biofilm formation.The MIC score of berberine ranged between 64 and 1 024 μg/ml.Berberine with the concentration of 1/2 MIC could inhibit the biofilm formation of MRSA(P＜0.001),and the inhibiting rate of biofilm formation of the MIC ≥512 μg/ml group was higher than that of the MIC≤128 μg/ml group and the MIC 256 μg/ml group(all P＜0.05).The re-sult under the fluorescence microscope showed that the fluorescence intensity of biofilms decreased with the rise of berberine concentration.Berberine could reduce the formation of amyloid fibrils and the release of eDNA,down-regulating the transcription levels of ica A,sasG,ebpS,fib,eno,clfA,clfB,bbp and fnbA genes(P＜0.05).CONCLUSION Berberine may inhibit the biofilm formation of MRSA by downregulating expression levels of related genes,interfering the formation of amyloid fibrils and blocking the release of eDNA,which may provide experimental bases for development of drugs resisting to MRSA biofilms.

ObjectiveTo analyze the epidemiological characteristics and trends of varicella in Taizhou, Zhejiang Province from 2014 to 2023, and to provide evidence for surveillance, prevention, and control of varicella in Taizhou. MethodIndividual case data of varicella reported in Taizhou from 2014 to 2023 were collected and analyzed. Descriptive epidemiological methods were used to analyze the distribution characteristics of varicella, and Joinpoint regression models were applied to assess trends in incidence rates. ResultsA total of 29 845 cases of varicella were reported in Taizhou from 2014 to 2023, with an annual incidence rate of 47.65/100 000. A total of 22 varicella-related public health events were recorded, accounting for 13.25% of all reported outbreaks during the same period. The annual reported incidence rates for males and females were 51.49/100 000 and 43.56/100 000, respectively. The average annual incidence rate was significantly higher in males than that in females. The age of onset was mainly from 5 to 20 years old, with a total of 20 382 cases reported, accounting for 68.29% of the total cases. Students constituted the majority of cases (62.15%). A distinct seasonal pattern was observed, with a major incidence peak from November to January of the next year and a secondary peak period from May to June. Varicella cases were reported in all counties and districts. The average annual incidence rates in urban districts, mountainous counties and coastal cities were 53.28/100 000, 50.24/100 000 and 41.46/100 000, respectively. Joinpoint regression identified 2019 as a turning point in the overall incidence trend, dividing the period into two phases, but the changes in trend of the two phases were not statistically different (P>0.05). Age-specific analyses revealed divergent trends: incidence rates among the 1‒ and 5‒year-old groups showed steady declines over the 10-year period (APC=-8.481%, P=0.006; APC=-11.690%, P=0.006). The incidence rate of 10‒year-old group showed a rapid decreasing trend from 2019 to 2023 (APC=-21.670%, P=0.026). In contrast, the 15‒ and 20‒year-old groups showed significant increases during the first phase (APC=20.531%, P=0.001; APC=10.778%, P=0.038). ConclusionFrom 2014 to 2023, the reported incidence rate of varicella was higher in males than that in females. The highest average annual incidence rate occurred in the 10‒19-year-old age group, with regional variations observed across different areas. The peak incidence period was from November to January of the following year. The overall incidence of varicella in Taizhou was slightly lower than that of the national average level. However, the number of varicella-related outbreaks reported during the same period remained relatively high, underscoring the need for continued and comprehensive prevention and control measures.

Background Other infectious diarrhea (OID) refers to infectious diarrhea other than cholera, dysentery, and typhoid/paratyphoid fever. In the global climate change context, frequent extreme temperature events pose a significant threat to population health, yet the association between extreme temperatures and OID remains unclear. Objective To understand the impact of extreme temperature events on the incidence of OID in Taizhou region, and provide a scientific basis for formulating targeted public health intervention strategies. Methods Case data of OID from 2016 to 2024 and meteorological and pollutant data of Taizhou, Zhejiang during the same period were collected. The case data were derived from National Notifiable Infectious Diseases Reporting System, while the meteorological data and pollutant data were obtained from National Meteorological Science Data Center and Taizhou Ecology and Environment Bureau, respectively. An extreme heat event is defined as a period of two or more consecutive days in the warm season during which the daily mean temperature exceeds the 90th percentile value for that season. Similarly, an extreme cold event is defined as a period of two or more consecutive days in the cold season during which the daily mean temperature falls below the 10th percentile value. A distributed lag nonlinear model based on Poisson regression was used to assess the impact of extreme temperatures on OID incidence. Furthermore, subgroup analyses were conducted by gender and age. Results From 2016 to 2024, a total of 108 670 OID cases were reported in Taizhou, with higher incidence in males (61 253 cases) than females (47 417 cases). In terms of single-day lag effect, exposure to extreme cold presented an inverted U-shaped risk pattern: a significant risk effect began to emerge on the 4th day after exposure, continued to rise, and reached a peak on the 7th day (RR=1.044, 95%CI: 1.029, 1.058), whereas extreme heat had no significant impact. In terms of cumulative lag effect, exposure to extreme cold presented a J-shaped cumulative effect curve: short-term exposure (0-2 days) showed no risk effect, but as time extended (0-9 days), a risk effect emerged and reached the maximum risk value during the 0-12 d cumulative period (RR=1.243, 95%CI: 1.057, 1.461). In contrast, extreme heat had no cumulative lag effect. The subgroup analysis revealed that under extreme cold exposure, the single-day lag effects for both males and females exhibited an inverted U-shaped curve, with the risk peaking on day 7 for males (RR=1.045, 95%CI: 1.026, 1.065) and day 8 for females (RR=1.041, 95%CI: 1.019, 1.064). The risk pattern in the 1-5 years age group was similar to that of the overall population but with a higher effect size (RR=1.063, 95%CI: 1.041, 1.085). In terms of the cumulative lag effects, the cumulative risk curves for both males and females under extreme cold exposure showed a J-shaped pattern with varied risk profiles. Significant variations in risk patterns were observed across different age groups. No significant cumulative lag effects were observed for extreme heat exposure in any subgroup. Conclusion Extreme cold can increase the incidence of OID in Taizhou, and the risk effects are heterogeneous among different groups. No risk effect is observed for extreme heat.

OBJECTIVE T o understand the resistance capability of berberine combined with levofloxacin in vitro to methicillin-resistant Staphylococcus aureus(MRSA).METHODS Totally 100 strains of MRSA were isolated from Shanghai Eighth People's Hospital from Jul.2023 to Jun.2024,the minimum inhibitory concentrations(MICs)of berberine and levofloxacin against the strains were determined by microbroth dilution method.The anti-bacterial effect of the combined use of the two drugs on MRSA was observed.The effects of the single and com-bined use of berberine and levofloxacin on sterilization of MRSA standard strain USA 300-LAC and their influence on cellular morphology were observed.The influence of berberine on mRNA levels of drug resistance genes and ef-flux pump-related genes in the standard strain USA 300-LAC and clinical strains was determined by means of real-time fluorescent quantitative PCR.RESULTS Among the 100 clinical isolates of MRSA,most of them were isola-ted from respiratory tract specimens of respiratory medicine department and geriatrics department,and 75.00％of the strains were resistant to levofloxacin.The MICs of both berberine and levofloxacin against the standard strain USA300-LAC were 128 μg/ml;the MICs against the clinical MRSA isolates were 64 to 1024 μg/ml and 0.125 to 256 μg/ml,respectively.Berberine combined with levofloxacin showed additive effect on 17(44.74％)strains of MRSA.The combined use of the two drugs showed the most remarkable in vitro antibacterial effect.The cellular structures of the strains were unclear and the contents of bacterial bodies increased when berberine and levofloxacin were used in combination.Berberine showed various degree of inhibitory effect on gyrA,gyrB,grlA and nor A genes.CONCLUSIONS Berberine is capable of resisting the MRSA and shows synergistic or additive effect with levofloxacin.The combined use of the two drugs may reduce the MIC against levofloxacin,destroy the morpholog-ical structure,and inhibit the expression of gyrA,gyrB,grlA and nor A genes.

Objective To compare the effectiveness of femoral neck system(FNS)and inverted triangle cannulated screws(ITCS)in the treatment of femoral neck fractures in young adults.Methods A retrospective study was conducted on 106 young and middle-aged patients who had been surgically treated for femoral neck fracture at our hospital from December 2020 to June 2022.The patients were assigned to FNS group(57 cases)or ITCS group(49 cases)according to the different internal fixations.The operation time,intraoperative fluoroscopy frequency,intraoperative blood loss,extra assisted reduction procedures(Kirschner wire prying reduction or open reduction),hospital stays,healing time,complications,postoperative recovery,and follow-up duration were compared between the two groups.Results The operation time,fluoroscopy frequency,and healing time in the FNS group were less than those in the ITCS group(P<0.001).The shortening degree and length of femoral neck in moderate and severe patients of the FNS group were lower than those of the ITCS group(P<0.001).The Harris score of the FNS group was higher than that of the ITCS group 12 months after surgery(P<0.001).There was no significant difference in intraoperative blood loss,reduction assistance,Garden index,or hospital stays between the two groups(P>0.05).Conclusion FNS is a better choice for internal fixation in patients with femoral neck fractures than ITCS,with faster recovery and less postoperative complications.

Objective To compare the effectiveness of femoral neck system(FNS)and inverted triangle cannulated screws(ITCS)in the treatment of femoral neck fractures in young adults.Methods A retrospective study was conducted on 106 young and middle-aged patients who had been surgically treated for femoral neck fracture at our hospital from December 2020 to June 2022.The patients were assigned to FNS group(57 cases)or ITCS group(49 cases)according to the different internal fixations.The operation time,intraoperative fluoroscopy frequency,intraoperative blood loss,extra assisted reduction procedures(Kirschner wire prying reduction or open reduction),hospital stays,healing time,complications,postoperative recovery,and follow-up duration were compared between the two groups.Results The operation time,fluoroscopy frequency,and healing time in the FNS group were less than those in the ITCS group(P<0.001).The shortening degree and length of femoral neck in moderate and severe patients of the FNS group were lower than those of the ITCS group(P<0.001).The Harris score of the FNS group was higher than that of the ITCS group 12 months after surgery(P<0.001).There was no significant difference in intraoperative blood loss,reduction assistance,Garden index,or hospital stays between the two groups(P>0.05).Conclusion FNS is a better choice for internal fixation in patients with femoral neck fractures than ITCS,with faster recovery and less postoperative complications.

OBJECTIVE To explore the effect and potential mechanisms of berberine on formation of biofilms of clinical methicillin-resistant Staphylococcus aureus(MRSA)isolates.METHODS Totally 95 clinical MRSA iso-lates were collected from Shanghai Eighth People's Hospital from Jan.2023 to Dec.2023.The 14 biofilm forma-tion-related genes in the strains were detected by polymerase chain reaction(PCR)and multiplex PCR,the mini-mum inhibitory concentration(MIC)of berberine was determined by microbroth dilution method,the effect of berberine on resistance of biofilm formation was evaluated by crustal violet staining,fluorescence microscope,Congo red agar plate and extracelluar DNA(eDNA).The transcription levels of 9 biofilm formation-related genes were detected by real-time fluorescent quantitative reverse transcription PCR.RESULTS All of the 95 strains of MRSA carried eno,clfA,clfB and icaA genes,the most widespread gene profile was bbp-eno-ebpS-fnbA-fib-clfA-clfB-icaA-sasG,and 29 strains had the phenotypes with strong capability of biofilm formation.The MIC score of berberine ranged between 64 and 1 024 μg/ml.Berberine with the concentration of 1/2 MIC could inhibit the biofilm formation of MRSA(P＜0.001),and the inhibiting rate of biofilm formation of the MIC ≥512 μg/ml group was higher than that of the MIC≤128 μg/ml group and the MIC 256 μg/ml group(all P＜0.05).The re-sult under the fluorescence microscope showed that the fluorescence intensity of biofilms decreased with the rise of berberine concentration.Berberine could reduce the formation of amyloid fibrils and the release of eDNA,down-regulating the transcription levels of ica A,sasG,ebpS,fib,eno,clfA,clfB,bbp and fnbA genes(P＜0.05).CONCLUSION Berberine may inhibit the biofilm formation of MRSA by downregulating expression levels of related genes,interfering the formation of amyloid fibrils and blocking the release of eDNA,which may provide experimental bases for development of drugs resisting to MRSA biofilms.