The engineering application of microbially induced carbonate precipitation(MICP)is limited by pH-dependent conformational dynamics of urease.Focusing on the α-subunit urease from Sporosarcina pasteurii,this study integrated conductivity experiments and constant-pH molecular dynamics simulations to analyze active site conformational dynamics and catalytic function across pH 3-11.Results showed that under neutral conditions(pH 7-8),key histidine residues(HIS139/HIS249)exhibited minimal dis-placement(＜0.5 ?),the longest hydrogen bond lifetime(＞8 ps),highest conformational stability(root mean square deviation,RMSD:0.15-0.18 nm),and optimal catalytic activity(conductivity change rate:0.03 mS/cm·min-1,CaCO3 precipitation:3.84 g).Extreme pH(pH 3/11)induced structural collapse(displacement up to 1.8 ?)and complete activity loss.Simulations revealed that neutral pH sta-bilizes a protonation-dependent cooperative allosteric network by maintaining active site cavity volume(～120 ?3)and moderate conformational coherence(correlation coefficient～0.8).This work deciphers the molecular mechanism of pH-regulated urease dynamics through protonation states,providing theoreti-cal support for MICP applications in acidic mine tailing remediation and alkaline soil stabilization.

This research investigated the contamination level,distribution of drug-resistant strains,and molecular epidemiologi-cal characteristics of Campylobacter,and further explored transmission pathways and prevention strategies.Cecum,chicken carcass,chicken product,and environmental samples,as well as swabs from workers'hands,were collected from a slaughterhouse in a large broiler group in the Jiaodong area between August 2023 and July 2024.Quantitative contamination assessment of Campylobacter in chicken carcasses and chicken products was performed.After microbial mass spectrometry identification,the representative strains of different links were selected for drug resistance testing and whole genome sequencing(WGS).On the basis of the sequencing results,the resistance genes,virulence genes,multilocus sequence typing(MLST),and phylogenetic characteristics of representative strains were analyzed.Homology comparisons were performed between isolates and strains from patients with diarrhea in the NCBI database.A total of 297 Campylobacter strains were isolated from 806 samples,and the overall detection rate was 36.85%.The detection rate of Campylobacter was highest in the evisceration process(47.33%),followed by the cutting process(35.64%).Overall,the Campylo-bacter detection rate first increased,then decreased,and subsequently increased.Drug sensitivity testing revealed that 90 isolates were resistant to nalidixic acid and ciprofloxacin,and 94.97%of isolates were resistant to tetracycline.WGS showed that both Campylo-bacter jejuni(C.jejuni)and Campylobacter coli(C.coli)carried many drug resistance and virulence genes.ST-14176 of C.jejuni was isolated for the first time herein.The predominant ST-8261 strain of C.jejuni and ST-860,ST-829,and ST-1586 strains of C.coli are known to cause human diarrhea.LOS expression genes associated with Guillain-Barré syndrome(GBS)were detected in both C.jejuni isolates from the slaughter chain and patients with GBS.Some strains exhibited close genetic relatedness to human-derived Campylo-bacter strains from the NCBI database.The detection rate of Campylobacter in the slaughterhouse first increased,then decreased,and subsequently increased,and the quantitative contamination level of each link was similar to the detection rate.Quantitative analysis of chicken carcasses/products revealed that the average bacterial load was highest in eviscerated carcasses(102.80 cfu/g),and the high-est amount of Campylobacter in chicken products reached 451.80 cfu/g.Abundant drug resistance genes and virulence genes were iden-tified,and the drug resistance genes were highly correlated with the drug resistance rate.Therefore,surveillance intensity and control measures for Campylobacter in slaughter processes should be strengthened.

This research investigated the contamination level,distribution of drug-resistant strains,and molecular epidemiologi-cal characteristics of Campylobacter,and further explored transmission pathways and prevention strategies.Cecum,chicken carcass,chicken product,and environmental samples,as well as swabs from workers'hands,were collected from a slaughterhouse in a large broiler group in the Jiaodong area between August 2023 and July 2024.Quantitative contamination assessment of Campylobacter in chicken carcasses and chicken products was performed.After microbial mass spectrometry identification,the representative strains of different links were selected for drug resistance testing and whole genome sequencing(WGS).On the basis of the sequencing results,the resistance genes,virulence genes,multilocus sequence typing(MLST),and phylogenetic characteristics of representative strains were analyzed.Homology comparisons were performed between isolates and strains from patients with diarrhea in the NCBI database.A total of 297 Campylobacter strains were isolated from 806 samples,and the overall detection rate was 36.85%.The detection rate of Campylobacter was highest in the evisceration process(47.33%),followed by the cutting process(35.64%).Overall,the Campylo-bacter detection rate first increased,then decreased,and subsequently increased.Drug sensitivity testing revealed that 90 isolates were resistant to nalidixic acid and ciprofloxacin,and 94.97%of isolates were resistant to tetracycline.WGS showed that both Campylo-bacter jejuni(C.jejuni)and Campylobacter coli(C.coli)carried many drug resistance and virulence genes.ST-14176 of C.jejuni was isolated for the first time herein.The predominant ST-8261 strain of C.jejuni and ST-860,ST-829,and ST-1586 strains of C.coli are known to cause human diarrhea.LOS expression genes associated with Guillain-Barré syndrome(GBS)were detected in both C.jejuni isolates from the slaughter chain and patients with GBS.Some strains exhibited close genetic relatedness to human-derived Campylo-bacter strains from the NCBI database.The detection rate of Campylobacter in the slaughterhouse first increased,then decreased,and subsequently increased,and the quantitative contamination level of each link was similar to the detection rate.Quantitative analysis of chicken carcasses/products revealed that the average bacterial load was highest in eviscerated carcasses(102.80 cfu/g),and the high-est amount of Campylobacter in chicken products reached 451.80 cfu/g.Abundant drug resistance genes and virulence genes were iden-tified,and the drug resistance genes were highly correlated with the drug resistance rate.Therefore,surveillance intensity and control measures for Campylobacter in slaughter processes should be strengthened.

Aim To explore the mechanism by which the compound Chaijin Jieyu formula(CCJJY)regulates the TLR4/NLRP3 signaling pathway to inhibit central oxidative stress and improve hippocampal synaptic plasticity damage in depression.Methods SD rats were randomly divided into the control group,chronic unpredictable mild stress group,sleep deprivation group,chronic unpredictable mild stress combined with sleep deprivation group,positive drug group(venlafax-ine+melatonin),low-dose group of CCJJY,medium dose group of CCJJY,and high-dose group of CCJJY,with nine rats in each group.Except for the control group,a rat model of depression complicated with in-somnia was established using chronic unpredictable mild stress combined with sleep deprivation.Depres-sion-like and sleep behaviors in rats were evaluated through weight,food intake,water maze,and pento-barbital sodium tests.ELisa was used to detect ROS,AANAT,and HPLC-EC was used to detect 5-HT con-tent,while Western blot/RT-PCR was used to detect the expression of IL-1β,TLR4,NLRP3,PSD-95,and SYN related proteins and mRNA.HE and Golgic stai-ning were used to observe the pathological changes in the third ventricle,hippocampus,and neuronal synap-ses.Results Compared with the control group,the depression-like behaviors of the model group rats were significant.The expression of IL-1β,TLR4,and NL-RP3 in the hippocampus increased,while the expres-sion of PSD-95 and SYN decreased.Activation of NL-RP3 inflammasomes led to "sleeve like" pathological changes in the third ventricle,with hippocampal neu-rons undergoing apoptosis and significant damage to neuronal synaptic plasticity.Compared with the model group,after intervention with CCJJY,the expression of ROS,IL-1β,TLR4,and NLRP3 decreased,while the expression of AANAT,5-HT,PSD-95,and SYN in-creased.Pathological damage to the third ventricle and hippocampal neurons was repaired.Conclusion The CCJJY improves hippocampal synaptic plasticity dam-age in depression by regulating the TLR4/NLRP3 sig-naling pathway to inhibit central oxidative stress.

The engineering application of microbially induced carbonate precipitation(MICP)is limited by pH-dependent conformational dynamics of urease.Focusing on the α-subunit urease from Sporosarcina pasteurii,this study integrated conductivity experiments and constant-pH molecular dynamics simulations to analyze active site conformational dynamics and catalytic function across pH 3-11.Results showed that under neutral conditions(pH 7-8),key histidine residues(HIS139/HIS249)exhibited minimal dis-placement(＜0.5 ?),the longest hydrogen bond lifetime(＞8 ps),highest conformational stability(root mean square deviation,RMSD:0.15-0.18 nm),and optimal catalytic activity(conductivity change rate:0.03 mS/cm·min-1,CaCO3 precipitation:3.84 g).Extreme pH(pH 3/11)induced structural collapse(displacement up to 1.8 ?)and complete activity loss.Simulations revealed that neutral pH sta-bilizes a protonation-dependent cooperative allosteric network by maintaining active site cavity volume(～120 ?3)and moderate conformational coherence(correlation coefficient～0.8).This work deciphers the molecular mechanism of pH-regulated urease dynamics through protonation states,providing theoreti-cal support for MICP applications in acidic mine tailing remediation and alkaline soil stabilization.

Aim To explore the mechanism by which the compound Chaijin Jieyu formula(CCJJY)regulates the TLR4/NLRP3 signaling pathway to inhibit central oxidative stress and improve hippocampal synaptic plasticity damage in depression.Methods SD rats were randomly divided into the control group,chronic unpredictable mild stress group,sleep deprivation group,chronic unpredictable mild stress combined with sleep deprivation group,positive drug group(venlafax-ine+melatonin),low-dose group of CCJJY,medium dose group of CCJJY,and high-dose group of CCJJY,with nine rats in each group.Except for the control group,a rat model of depression complicated with in-somnia was established using chronic unpredictable mild stress combined with sleep deprivation.Depres-sion-like and sleep behaviors in rats were evaluated through weight,food intake,water maze,and pento-barbital sodium tests.ELisa was used to detect ROS,AANAT,and HPLC-EC was used to detect 5-HT con-tent,while Western blot/RT-PCR was used to detect the expression of IL-1β,TLR4,NLRP3,PSD-95,and SYN related proteins and mRNA.HE and Golgic stai-ning were used to observe the pathological changes in the third ventricle,hippocampus,and neuronal synap-ses.Results Compared with the control group,the depression-like behaviors of the model group rats were significant.The expression of IL-1β,TLR4,and NL-RP3 in the hippocampus increased,while the expres-sion of PSD-95 and SYN decreased.Activation of NL-RP3 inflammasomes led to "sleeve like" pathological changes in the third ventricle,with hippocampal neu-rons undergoing apoptosis and significant damage to neuronal synaptic plasticity.Compared with the model group,after intervention with CCJJY,the expression of ROS,IL-1β,TLR4,and NLRP3 decreased,while the expression of AANAT,5-HT,PSD-95,and SYN in-creased.Pathological damage to the third ventricle and hippocampal neurons was repaired.Conclusion The CCJJY improves hippocampal synaptic plasticity dam-age in depression by regulating the TLR4/NLRP3 sig-naling pathway to inhibit central oxidative stress.

Objective This study aimed to investigate the potential relationship between urinary metals copper (Cu), arsenic (As), strontium (Sr), barium (Ba), iron (Fe), lead (Pb) and manganese (Mn) and grip strength. Methods We used linear regression models, quantile g-computation and Bayesian kernel machine regression (BKMR) to assess the relationship between metals and grip strength.Results In the multimetal linear regression, Cu (β=-2.119), As (β=-1.318), Sr (β=-2.480), Ba (β=0.781), Fe (β= 1.130) and Mn (β=-0.404) were significantly correlated with grip strength (P < 0.05). The results of the quantile g-computation showed that the risk of occurrence of grip strength reduction was -1.007 (95％ confidence interval:-1.362, -0.652; P < 0.001) when each quartile of the mixture of the seven metals was increased. Bayesian kernel function regression model analysis showed that mixtures of the seven metals had a negative overall effect on grip strength, with Cu, As and Sr being negatively associated with grip strength levels. In the total population, potential interactions were observed between As and Mn and between Cu and Mn (Pinteractions of 0.003 and 0.018, respectively).Conclusion In summary, this study suggests that combined exposure to metal mixtures is negatively associated with grip strength. Cu, Sr and As were negatively correlated with grip strength levels, and there were potential interactions between As and Mn and between Cu and Mn.

Objective To design a portable intelligent cleaner for medical lumen instruments to enhance cleaning efficiency.Methods The portable intelligent cleaner had a box-body shape and a shell made of 304 stainless steel,which was composed of a circuit control board,a micro pump,lithium batteries,a charging interface,a rinse tube and connectors.The circuit control board used a STM32G030C8T6 integraged circuit,which was equipped with a countdown digital tube to display the time left for cleaning;the micro pump and lithium batteries were placed at the inner wall of the box bottom,the charging interface and water inlet/outlet inteface were put on the outside of the front wall of the box bottom,the water inlet/outlet interface was connected with a silicon rinse tube linked to an adapter at its distal end,and the adapters with different calibers were compatible with sizes of medical lumen instruments.Totally 9 672 pieces of lumen instruments received by some hospital's disinfection supply center from May to October 2021 were divided into 2 groups with the convenience sampling method,with 4 836 pieces in each group.The odd-numbered instruments were enrolled into a control group and cleaned with an ultrasonic cleaner and a lumen brush,and the even-numbered instruments were included into an experimental group and cleaned conventionally after pretreatment by the intelligent cleaner.The two groups were compared in terms of eaning efficiency and satisfaction.Results Testing by visual inspection,magnifying glass with light source and white stripe method showed that the experimental group behaved better than the control group in the cleaning qualification rate,whose satisfaction rate(100％)was also higher than that of the control group(86.53％),with all the differences being statistically significant(P＜0.05).Conclusion The portable cleaner with easy operation enhances the cleaning quality and efficiency for medical lumen instruments.[Chinese Medical Equipment Journal,2024,45(10):114-117]

Objective To explore the incidence and imaging characteristics of bifid ribs of Tibetan population in Kangbei area by multi-slice spiral CT(MSCT),in order to provide imaging reference for clinical diagnosis and treatment.Methods The imaging data of 1 253 Tibetan patients(661 males and 592 females)in Kangbei area who underwent chest MSCT examination were retrospectively analyzed.The incidence of bifid ribs and its differences between genders and sides were counted.The location of bifid ribs,the morphological charac-teristics of the junction of bifid ribs and costal cartilage,and the change of adjacent intercostal space were observed.Results Among 1 253 patients with chest MSCT,57 patients had bifid ribs,with a total of 64 bifid ribs.The incidence of bifid ribs at the patient level was 4.55%,of which 51 cases had single bifid rib and 6 cases had multiple bifid ribs;the incidence of bifid ribs in male was 4.99%(33/661),the female was 4.05%(24/592),and the difference between genders was not statistically significant(P>0.05).The incidence of bifid ribs was 56.14%(32/57)on the right side,33.33%(19/57)on the left side,and 10.53%(6/57)on both sides,the differences between different sides were statistically significant(P<0.05).The bifid ribs were found in the 2nd to 8th ribs,mainly in the 3rd to 5th ribs.A total of 55(85.94%)junctions of bifid ribs and costal cartilage were obturator type,5(7.81%)junctions were incompletehole shape type,3(4.69%)junctions were double costal cartilage type and 1(1.56%)junction was other type;62(96.88%)junctions were narrow in the upper intercostal space.Conclusion The incidence of bifid ribs of the Tibetan population in Kangbei area is 4.55%,which mainly occurs in the 3rd to 5th ribs,and the obturator type is more common,with the upper intercostal space narrow.MSCT can make accurate diagnosis of bifid ribs and provide accurate imaging evaluation for clinical practice.

Interventions for endometriosis(EMs)include surgical excision of lesions and hormonal therapy,which usually have limited efficacy and adverse drug reactions.Traditional Chinese medicine(TCM)has the multi-component and multi-target characteristics,which can help patients achieve good clinical benefits by intervening in different parts of the disease.In this paper,we briefly discuss the modern pharmacology of Sanlang and Curcuma longa,and deeply summarize the possible mechanisms of action of TCM monomer and classical compound extracts and their active ingredients through signal pathways in inflammation,immune system,angiogenesis,hormone regulation,etc.,so as to provide theoretical bases for the clinical use of TCM monomers,drug-to-drug groups and compounds in the treatment of EMs.