Aim To determine whether the micro kinetic chro-mogenic method can meet the requirements of Chinese Pharma-copoeia,as a supplement to the existing bacterial endotoxin test method.Methods Using micro kinetic chromogenic horseshoe crab reagent,the sample volume per well was 25 μL,the detec-tion wavelength was 405 nm,the preset OD value was 0.05,and the detection was carried out by half-well enzyme plate.In accordance with the provisions of"9101 Guiding Principles for Validation of Drug Quality Analysis Methods"in the fourth part of the 2020 edition of the People's Republic of China Pharmaco-poeia,the methodological verification of 7 items of specificity,accuracy,precision,limit of quantification,linearity,range and durability was carried out according to the specific requirements of the"quantitative"item in the"Determination of Impurities".The variety suitability study was conducted on 74 batches of samples from 48 drug varieties,and 143 batches of samples from 76 drug varieties(including 133 batches of negative samples and 10 batches of positive samples)were tested daily,and the re-sults were compared with the results of traditional color rendering method.Results The method of microdynamic color develop-ment met the requirements of the Pharmacopoeia of the People's Republic of China for quantitative methods.The results of varie-tal applicability and consistency comparison showed that the mi-crodynamic color development method had better equivalence compared with the traditional color development method.Con-clusion The micro kinetic chromogenic method can be promo-ted as a supplementary alternative to the existing bacterial endo-toxin methods.

Aim To investigate the effect of vanillin on the regulation of cyclic guanylate adenylate synthetase(cGAS)/stimulator of interferon gene(STING)signa-ling pathway on hepatic tissue injury in rats with intra-hepatic cholestasis(IC).Methods SD rats were randomly divided into normal group,IC group,vanillin group,cGAS overexpression group,and vanillin+cGAS overexpression group,with continuous adminis-tration for seven days.The body weight,liver weight and liver to body weight ratio of rats were measured.Liver function(ALT,AST,ALP,LDH),IC(TBIL,TBA)and liver fibrosis(HA,LN,PC Ⅲ)index were determined by ELISA.Liver pathology and fibrosis were observed using HE and Masson staining,and col-lagen volume fraction was calculated.The expression of cGAS/STING pathway related proteins in liver tissue was detected by Western blot.Results Vanillin could improve liver pathology and fibrosis,increase body weight,and decrease liver weight,ALT,AST,ALP,LDH,TBIL,TBA,HA,LN,PC Ⅲ,collagen volume fraction,cGAS,STING protein in IC rats(P＜0.05).Overexpression of cGAS could reverse the effects of vanillin on the above indicators in IC rats(P＜0.05).Conclusions Vanillin may improve liver function,IC,liver fibrosis,and liver tissue damage in IC rats by downregulating the cGAS/STING signaling pathway.

Objective To investigate the safety and efficacy of novel bioabsorbable vascular scaffold(BVS)in the treatment of patients with complex coronary artery disease.Methods This was a retrospective,matched,single-center observational study.45 patients with coronary atherosclerotic cardiopathy received BVS treatment in the cardiovascular medicine department Department of the Affiliated Hospital of Guangdong Medical University from June 2020 to June 2021(BVS),and 45 patients treated with drug-eluting stents(DES)group were selected according to matching study requirements during the same period.Baseline,surgical,and follow-up data were compared between the two groups to evaluate safety and efficacy.The main measures of safety were:surgical time,intraoperative adverse events,etc.,and the end point of efficacy was target lesion failure(TLF),including cardiac death,target vessel myocardial infarction,and ischa-driven target lesion revascularization.Results A total of 90 patients were enrolled in this study,all of whom were followed up for at least 3 years.There were 20 cases of bifurcation lesions and 25 cases of diffuse long lesions in the two groups,and 50 cases of imaging were reviewed among the 90 patients.The proportion of stable coronary heart disease,history of diabetes,history of hypertension,history of smoking,pre-dilated balloon pressure and postoperative diastolic blood pressure in BVS group was higher than that in DES group,and the proportion of family history was lower than that in DES group(all P＜0.05).There were no statistically significant differences in the rates of cardiac death,target vessel myocardial infarction,and ischemia-driven revascularization of target lesions between the two groups(all P＞0.05).Binary Logistic regression model analysis showed that the diameter stenosis ratio of target lesions was an independent risk factor for intrastent restenosis(OR 2.786,95％CI 1.096-7.081,P=0.031).Conclusions Compared with traditional DES,BVS implantation has consistent safety and efficacy in the treatment of complex coronary artery disease within 3 years.The diameter stenosis ratio of target lesions was an independent risk factor for intrastent restenosis.

Objective To propose a Q factor-based fatigue vibration evaluation method of the ultrasonic knife tip.Methods Firstly,an ultrasonic cutter fatigue testing table was established to realize repeated cutting,which was composed of a power supply module,a three-axis moving module,an ultrasonic cutter clamping module and a control module.Secondly,10 ultrasonic knives of some brand underwent fatigue testing with the table,during which non-contact measurement of the ultrasonic knife tip vibration was carried out and the Q factors were calculated at the five periods of the fatigue test,including the periods before cutting,after 500 times of cutting,after 1 000 times of cutting,after 2 000 times of cutting and after 3 000 times of cutting.Finally,the average cutting speed and burst pressure for coagulated vessels were computed at each period to validata the effectiveness of the method proposed.Results It's indicated that Q factor could effectively reflect the fatigue degradation of the ultrasonic knife tip,while the average cutting speed and burst pressure for coagulated vessels were difficult to efficiently evaluate the fatigue degradation level of the ultrasonic knife tip due to the uncertainty factors in the measurement process.Conclusion The proposed Q factor-based evaluation method can directly evaluate fatigue vibration of the ultrasonic knife tip in an accurate and quantitative manner.[Chinese Medical Equipment Journal,2024,45(6):17-22]

Objective To propose an evaluation and screening indicator for the reliability of emergency ventilators.Methods Firstly,a regression model was used to clean the data and remove noise to ensure the accuracy of regression analysis.Then,four groups of highly correlated data combinations,including inspiratory tidal volume-minute expiratory volume,peak airway pressure-minute expiratory volume,peak airway pressure-inspiratory tidal volume and positive end-expiratory pressure(PEEP)-mean airway pressure,were determined with the methods of curve fitting and transfer function,and the difference between the theoretical output and the actual output of the data combinations was regarded as an indicator to judge whether the ventilator functioned well or not;finally,the indicator proposed was applied to single and multiple ventilators,and the feasibility of the indicator was determined by the proportion of the ventilators functioning well.Results The evaluation results with a single ventilator showed the four groups of data combinations had the actual output fitted well with the theoretical output,and all the differences between the theoretical output and the actual output were lower than the threshold;the results with multiple ventilators indicated there were 71.49％ventilators functioning well,which was very close to the actual result that 72％ventilators behaved well.Conclusion The evaluation and screening indicator for emergency ventilators has high feasibility,and theoretical support is provided for reliability assessment and selection of series of emergency treatment equipment.[Chinese Medical Equipment Journal,2024,45(7):8-16]

Objective To carry out accurate quantative evaluation of MRI scanning noise based on laser vibrometry technology.Methods Skull and spine MRI was performed with mute and conventional sequences.A laser vibrometry device was used to sample the surface vibration noise at the outer edge of the inspection hole of MRI system according to GB/T 16539-1996 Acoustics—Determination of sound power levels of noise sources using vibration velocity—Measurement for seal machinery,and the indicators of sound power level,sound pressure level and perceived noise level obtained by the three calculation methods(LPN1,LPN2 and LPN3)were analyzed with some dedicated MRI noise analysis software.Results The peak sound pressure levels for conventional and mute sequences of skull scanning were 81 and 63 dB(A),respectively,and mute sequence reduced the noise level significantly;the peak sound pressure levels for conventional and mute sequences of spine scanning were 79 and 75 dB(A),respectively,and the noise reduction level was significantly lower than that of skull scanning.Significant differences in noise reduction were not found in spine scanning sequences,while were found in skull scanning sequences.During spine and skull scanning LPN1,LPN2 and LPN3 obtained by the three calculation methods of conventional and mute sequences were all higher than the overall sound power and overall pressure levels obviously.Conclusion Mute sequence can not realize linear noise reduction for the whole frequency band,the perceived noise of the human ear during MRI scanning is related directly to the scanning sequence,and there may be some bias when only one physical indicator is involved in the noise evaluation of MRI system.[Chinese Medical Equipment Journal,2024,45(10):20-24]

Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75％(27/36);boys accounted for 64％(23/36).Among the 36 neonates,31(86％)had disease onset within 3 days after birth,and 19(53％)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61％)had left cerebral infarction and 13(36％)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75％)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72％)and seizures in 10 neonates(34％).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33％,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44％(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.

Objective To explore the optimal morning discharge time and pipeline disinfection frequency of the fi-nal rinse water from the endoscopy center according to the microbial culture results.Methods Different morning discharge timing and number of bacterial colonies in the pipeline for the final rinse water from the endoscopy center of a hospital in Jiangsu Province were monitored.Microbial detection was conducted on water samples collected from the two final rinse water sampling sites in the endoscopy room after 0,1,3,5,and 7 minutes of discharge,respec-tively(100 mL each,continuously monitored for 35 days,with 70 samples at each time point)to explore the optimal discharge timing.The optimal disinfection frequency of pipelines for purified water was explored according to the determined optimal morning discharge timing.Two samples were taken daily from 2 sampling sites after pipeline disinfection and continued for 5 weeks,resulting in 70 samples in total.Results Sampling and monitoring of the fi-nal rinse water at different morning discharge time points showed that the median numbers of bacterial colonies at 0,1,3,5,and 7 minutes were 745.00(373.00,1 452.50),150.00(96.75,235.75),44.00(38.00,48.00),12.00(5.00,18.00),and 6.00(4.00,9.00)CFU/100 mL,respectively.Except the difference between the 5 minute group and the 7 minute group(P＞0.05),differences among all the other groups were statistically significant(all P＜0.05).The median of the 0,1,3,and 5 minute groups was＞10 CFU/100 mL,while the median of the 7 mi-nute group was＜10 CFU/100 mL,within the qualified range.The discharge time was therefore determined to be 7 minutes.The average numbers of bacterial colonies from the final rinse water samples taken at different time points after pipeline disinfection(1,2,3,4,and 5 weeks after disinfection)were(4.21±0.86),(4.43±0.71),(6.00±0.56),(6.43±0.45),and(13.57±1.03)CFU/100 mL,respectively.The qualification rates of pipeline in terms of bacterial colony were 100％,100％,100％,100％,and 28.57％,respectively.The differences of average num-bers of bacterial colonies from the final rinse water samples taken at different time points after pipeline disinfection were statistically significant(P＜0.001).The average number of bacterial colonies 5 weeks after pipeline disinfec-tion was different from those after 1,2,3,and 4 weeks,with statistically significant differences(all P＜0.05),while no statistically significant differences among the other groups were observed(all P＞0.05).The optimal disin-fection frequency for the purified water pipeline was once every 4 weeks.Conclusion The final rinse water remai-ning in the terminal of pipeline is contaminated to a certain degree.It is recommended to discharge water in the morning for 7 minutes before using it,and disinfect the purified water pipeline every 4 weeks.

Objective To explore the antimicrobial resistance of carbapenem-resistant Klebsiella pneumoniae(CRKP)isolated from blood and the related risk factors for infection in patients.Methods Clinical data of 383 KP-infected patients from whose blood Klebsiella pneumoniae(KP)were isolated during hospitalization period in a hos-pital from January 2018 to December 2021 were retrospectively analyzed.Patients were divided into CRKP group(n=114)and non-CRKP group(n=269)based on antimicrobial resistance.According to the prognosis,114 patients in the CRKP group were subdivided into the death group(n=30)and the survival group(n=84).General informa-tion,underlying diseases,antimicrobial use,and infection outcomes of two groups of patients were compared,and risk factors for infection and death after infection were analyzed.Results The resistance rates of KP to tigecycline and compound sulfamethoxazole showed upward trends,with statistically significant differences(both P=0.008).The CRKP group had higher resistance rates to amikacin,aztreonam,compound sulfamethoxazole,ciprofloxacin,cefepime,cefoperazone/sulbactam,piperacillin/tazobactam,tigecycline,ceftazidime,tobramycin,and levofloxacin,as well as higher in-hospital mortality than the non-CRKP group,with statistically significant differences(all P＜0.05).Acute pancreatitis prior to infection(OR=16.564,P＜0.001),hypoalbuminemia(OR=8.588,P＜0.001),stay in in-tensive care unit prior to infection(OR=2.733,P=0.017),blood transfusion(OR=3.968,P=0.001),broncho-scopy(OR=5.194,P=0.014),surgery within 30 days prior to infection(OR=2.603,P=0.010),and treatment with carbapenems(OR=2.663,P=0.011)were independent risk factors for the development of CRKP blood-stream infection(BSI).Cardiac insufficiency before infection(OR=11.094,P=0.001),combined with pulmonary infection(OR=20.801,P=0.010),septic shock(OR=9.783,P=0.002),disturbance of consciousness(OR=11.648,P=0.001),and receiving glucocorticoid treatment(OR=5.333,P=0.018)were independent risk factors for mortality in patients with CRKP BSI.Conclusion The resistance rate of KP from BSI to tigecycline and com-pound sulfamethoxazole presents upward trend.Underlying diseases,invasive procedures,and carbapenem treat-ment are closely related to CRKP BSI.Cardiac insufficiency,pulmonary infection,septic shock,disturbance of con-sciousness,and glucocorticoid treatment can lead to death of patients with CRKP BSI.

The growth of three plague phages from Qinghai Plateau in two Yersinia pestis strains(plague vaccine strains EV76 and 614F)and four non-Yersinia pestis strains(Yersinia pseudotuberculosis PTB3,PTB5,Escherichia coli V517,and Yersinia enterocolitica 52302-2)were detected through a micromethod based on the OmniLogTM microbial identification system and by the drop method,to provide a scientific basis for future ecological studies and classification based on the host range.For plague vaccine strains EV76 and 614F,successful phage infection and subsequent phage growth were observed in the host bacte-rium.Diminished bacterial growth and respiration and a concomitant decrease in color were observed with the OmniLogTM mi-crobial identification system at 33 ℃ for 48 h.Yersinia pseudotuberculosis PTB5 was sensitive to Yersinia pestis phage 476,but Yersinia pseudotuberculosis PST5 was insensitive to phage 087 and 072204.Three strains of non-Yersinia pestis(Yersinia pseudotuberculosis PTB3,Escherichia coli V517,and Yersinia enterocolitica 52302-2)were insensitive to Yersinia pestis pha-ges 087,072204,and 476 showed similar growth curves.The growth of phages 476 and 087,as determined with the drop method,in two Yersinia pestis strains(plague vaccine strains EV76 and 614F)and four non-Yersinia pestis strains(Yersinia pseudotuberculosis PTB3,Escherichia coli V517,and Yersin-ia enterocolitica 52302-2)showed the same results at 37 ℃,on the basis of comparisons with the OmniLogTM microbial i-dentification system;in contrast,phages 072204 did not show plaques on solid medium at 37 ℃ with plague vaccine strains EV76 and 614F.Determination based on the OmniLogTM detection system can be used as an alternative to the traditional determination of the host range,thus providing favorable application val-ue for determining the interaction between the phage and host bacteria.