Human exhaled breath has great application prospects,e.g.,monitoring pharmacokinetics,disease diagnosis,due to its advantages such as non-invasive and high-frequency sampling.Breath samples can be collected from the oral and nasal cavity.However,the oral and nasal environment affect the chemical composition of breath sample.Therefore,the investigation on the chemical composition of mouth-exhaled breath and nose-exhaled breath is crucial for selection of appropriate sampling strategy for individual studies.In this work,secondary electrospray ionization-high resolution mass spectrometry(SESI-HRMS)was applied to analysis of respiratory metabolomics in real time.A quantitative analysis approach was established for 9 kinds of volatile organic compounds(VOCs)e.g.2-butanone,2-pentanone,ethyl acetate,methyl methacrylate,toluene,styrene,mesitylene,isoprene and limonene.The limit of detection was 2.3?240.8 ng/m3.The intra-day(n=6)and inter-day(n=18)relative standard deviations were 0.6%?4.6%and 4.3%?12.2%,respectively.Nine healthy subjects were recruited to investigate the chemical composition of mouth-exhaled and nose-exhaled breath.The results showed the good performance in quantitative analysis of 9 VOCs in breath air.It was found that the number of unique component(m/z)detected in mouth-exhaled breath(167)was 2.2 times greater than that detected in nose-exhaled breath(76),which might result from the complex environment in oral cavity.The signal intensity of commun component(163)was significantly different between mouth-exhaled breath and nose-exhaled breath.Additionally,the elemental composition analysis showed that the proportion of polar compounds detected in nose-exhaled breath was higher than that in mouth-exhaled breath.This study demonstrated that there was significant differences in the chemical composition between mouth-exhaled and nose-exhaled breath,which provided a theoretical basis for selection of exhalation mode.

Objective:Quantified MRCP imaging data was used as a reference for design and preparation of a modified percutaneous transhepatic cholangio drainage (PTCD) tube.Methods:3.0 T upper abdominal MR and MRCP imaging data of 2 300 patients treated from July 2015 to July 2020 at the Department of Radiology of the Affiliated Cancer Hospital of Zhengzhou University were screened and a total of 381 patients diagnosed with biliary duct structures were identified. Causative etiologies among these patients included pancreatic adenocarcinoma (pancreatic head), cholangiocarcinoma, ampullary carcinoma, as well as intrahepatic and/or extrahepatic bile duct dilation. An improved PTCD tube was designed based on MRCP quantification of left and right hepatic and common hepatic duct length.Results:In the setting of biliary obstruction caused by malignancy, the distance of the left hepatic duct from its origin to the point of left and right hepatic duct confluence was 15.9±3.8 mm, while the distance of the right hepatic duct from its origin to the point of left and right hepatic duct confluence was 12.4±3.2 mm; the length of the bile duct from its origin to the point of left and right hepatic duct confluence was 34.0±8.1 mm. The improved PTCD tube design incorporated an altered length of the drainage orifice.Conclusion:MRCP imaging of the biliary tract is effective for measuring biliary tract length in the setting of pathological dilation. Based on our biliary tract measurements, a modified PTCD tube was designed to more effectively meet drainage requirements and manage biliary obstruction caused by Bismuth-Corlette type Ⅱ and Ⅲ malignancies.

Objective To analyze the pathogenic bacteria and drug resistance of peritoneal dialysis-associated peritonitis(PDAP),and provide a clinical reference for the rational use of antibiotics.Methods The demographic data of PDAP patients admitted to the peritoneal dialysis(PD)Center of the First Affiliated Hospital of Soochow University from July 1,2015 to December 30,2021 were collected,and the pathogens,drug resistance and prognosis were retrospectively analyzed.Results A total of 150 episodes of PDAP occurred in 92 patients.The positive rate of PD fluid culture was 61.33％,including 65 cases(70.65％)of Gram-positive(G+)bacteria,mainly Staphylococcus and Streptococcus.Gram-negative(G-)bacteria were in 16 cases(17.39％),mainly Escherichia coli and Enterobacter cloacae.There were 11 cases(11.96％)of multiple infections,including 5 cases of combined fungal infection.From 2016 to 2021,the incidence of G+bacteria-related PDAP decreased from 14 to 8 cases.G+strains were resistant to methicillin(35.00％),and were sensitive to linezolid(100.00％),teicoplanin(100.00％)and rifampicin(100.00％).The sensitivity rate to vancomycin was 98.59％.G-strains were sensitive to ceftazidime(86.36％),ceftizoxime(88.89％)and amikacin(100.00％).The MIC of vancomycin against Staphylococcus showed an upward trend in 2019-2021.The overall cure rate of PDAP was 81.33％in patients who responded to antibiotic treatment,and the cure rate of G+bacteria was higher than that of multiple infections(89.23％vs.36.36％,P＜0.01).The outcome of patients with multiple infections,especially those with concurrent fungal infection was poor.Conclusion The incidence of PDAP in the PD center has shown a decreasing trend in recent years.G+bacteria are still the main pathogenic bacteria causing PDAP,and they are highly resistant to methicillin,so vancomycin should be used as empirical therapy.For G-bacteria,cefotaxime and amikacin can be chosen as empirical therapy.There is a drift in the MIC values of vancomycin against Staphylococcus in the study period,so it is necessary to monitor the MIC of vancomycin against Staphylococcus and its changing trend.

Objective To understand the respiratory protection competency of staff in hospitals.Methods Staff from six hospitals of different levels and characteristics in Beijing were selected,including doctors,nurses,medical technicians,and servicers,to conduct knowledge assessment on respiratory protection competency.According to exposure risks of respiratory infectious diseases,based on actual cases and daily work scenarios,content of respira-tory protection competency assessment was designed from three aspects:identification of respiratory infectious di-seases,transmission routes and corresponding protection requirements,as well as correct selection and use of masks.The assessment included 6,6,and 8 knowledge points respectively,with 20 knowledge points in total,all of which were choice questions.For multiple-choice questions,full marks,partial marks,and no mark were given respective-ly if all options were correct,partial options were correct and without incorrect options,and partial options were correct but with incorrect options.Difficulty and discrimination analyses on question of each knowledge point was conducted based on classical test theory.Results The respiratory protection competency knowledge assessment for 326 staff members at different risk levels in 6 hospitals showed that concerning the 20 knowledge points,more than 60％participants got full marks for 6 points,while the proportion of full marks for other questions was relatively low.Less than 10％participants got full marks for the following 5 knowledge points:types of airborne diseases,types of droplet-borne diseases,conventional measures for the prevention and control of healthcare-associated infec-tion with respiratory infectious diseases,indications for wearing respirators,and indications for wearing medical protective masks.Among the 20 knowledge questions,5,1,and 14 questions were relatively easy,medium,and difficult,respectively;6,1,4,and 9 questions were with discrimination levels of ≥0.4,0.30-0.39,0.20-0.29,and ≤0.19,respectively.Conclusion There is still much room for hospital staff to improve their respiratory protection competency,especially in the recognition of diseases with different transmission routes and the indications for wearing different types of masks.

Objective:To investigate the endorectal ultrasound findings in rectal neuroendocrine neoplasms (R-NEN) and to compare the diagnostic performance of ERUS and MRI for T staging of R-NENs.Methods:The imaging features of 77 confirmed R-NEN cases with different pathological grades in the Sixth Affiliated Hospital, Sun Yat-sen University from August 2015 to August 2021 were retrospectively analyzed and the abilities of ERUS and MRI for T staging of R-NENs were compared.Results:A total of 77 R-NEN patients underwent preoperative ERUS examinations and detected lesions in 62 patients with a detection rate of 80.52%. Among them, 30 cases underwent simultaneous MRI examinations, and detected lesions in 25 cases with a detection rate of 83.33%, without statistical difference between MRI and ERUS ( P>0.05). R-NEN exhibited hypoechoic nodules with rich blood flow in the submucosa on ERUS. Grade G1 and G2 tumors generally had sizes less than 10 mm, clear boundaries, and regular shapes, while G3 was typically large, irregular, poorly defined, and more likely to invade the musculi propria and serous layer. G3 demonstrated a more profound infiltration level, a less defined border, and a larger diameter than G1 and G2, with statistically significant differences (all P<0.05). For T staging, the accuracy of ERUS was 86.67%, and that of MRI was 94.67%, with no statistical difference ( P>0.05). Conclusions:ERUS is effective for detecting R-NEN lesions and useful for tumor grading with comparable performance to MRI, and should be recommended for preoperative evaluation of neuroendocrine tumors.

Objective To investigate the dosimetric effects of different calculation grid size(CGS)in helical tomotherapy(HT)planning system on stereotactic body radiation therapy(SBRT)for non-small cell lung cancer(NSCLC).Methods Nine NSCLC patients receiving radiation therapy for the first time at some hospital from March 2019 to December 2022 were selected as the subjects.SBRT planning was carried out through the HT system with three different CGS plans(Fine,Normal,and Coarse)and the same pitch,modulation factor(MF)and optimization conditions,and the target area indexes of the three CGS plans were compared including conformity index(CI),homogeneity index(HI),dosimetric parameters of the organ at risk(OAR),point dose verification pass rate,treatment time,number of monitor units and Sinograms.SPSS 22.0 was used for statistical analysis.Results For target area HI,there weres significant differences between CGS Fine plan and Coarse plan and between CGS Normal plan and Coarse plan(P＜0.05),while no statistical differences were found between CGS Fine plan and Normal plan(P＞0.05).For target area CI,there were significant differences between CGS Fine plan and Coarse plan(P＜0.05),while no statistical differences were found between CGS Fine plan and Normal plan and between CGS Normal plan and Coarse plan(P＞0.05).For OAR dosimetric parameters,CGS Fine plan and Coarse plan had significant differences in heart Dmax and Dmean,esophageal Dmax and Dmean,V5,V20,V30 and Dmean of the whole lung and affected lung,V5 and Dmax of the affected lung and heart V10 and V30(P＜0.05),CGS Normal plan and Coarse plan had obvious differences in esophageal Dmax(P＜0.05),and the remained dosimetric parameters were not statistically significant(P＞0.05).Fine,Normal and Coarse plans had the point dose verifica-tion pass rates being 0.96％,1.50％and 1.77％,respectively.In terms of treatment time and number of monitor units,there were significant differences between Fine plan and Coarse plan(P＜0.05)while no statistical differences were found between Fine and Normal plans and between Normal and Coarse plans(P＞0.05).Sinograms analyses showed Fine plan had evenly distributed segment color gradient,Coarse plan had areas of very dark and very light color gradients and Normal plan was somewhere in between.Conclusion Low CGS has to be used as much as possible to obtain accurate dose distribution during SBRT planning for NSCLC patients,which contributes to the execution of the radiation therapy plan and the prevention of ad-verse effects.[Chinese Medical Equipment Journal,2024,45(2):52-57]

Objective To design a novel oxygenator to solve the existing problems of extracorporeal membrane oxygenation(ECMO)machine in high transmembrane pressure difference,low efficiency of blood oxygen exchange and susceptibility to thrombosis.Methods The main body of the oxygenator vascular access flow field was gifted with a flat cylindrical shape.The topology of the vascular access was modeled in three dimensions,and the whole flow field was cut into a blood inlet section,an inlet buffer,a heat exchange zone,a blood oxygen exchange zone,an outlet buffer and a blood outlet section.The oxygenator was compared with Quadrox oxygenator by means of ANSYS FLUENT-based simulation and prototype experiments.Results Simulation calculations showed the oxygenator designed was comparable to the clinically used ones in general,and gained advantages in transmembrane pressure difference,blood oxygen exchange and flow uniformity.Experimental results indicated that the oxygenator behaved better than Quadrox oxygenator in transmembrane pressure difference and blood oxygen exchange.Conclusion The oxygenator has advantages in transmem-brane pressure difference,temperature change,blood oxygen ex-change and low probability of thrombosis.[Chinese Medical Equipment Journal,2024,45(3):23-28]

Objective To investigate the radiotherapy dose impacts of different jaw widths on stereotactic body radiotherapy(SBRT)for hepatocellular carcinoma(HCC)with the hilical tomotherapy(HT)planning system.Methods Totally 16 HCC patients who received radiotherapy at some hospital from March 2021 to August 2023 were selected,and the planning was carried out with the same pitch,modulation factors and optimization conditions and the jaw widths being 1.0,2.5 and 5.0 cm.The dosimetric differences due to the jaw widths in planned targets and organs at risk(OAR)were compared,and the planned treatment time,monitor unit,gantry rotations and gantry period were evaluated.SPSS 22.0 was used for statistical analysis.Results Better dosimetric parameters and lower doses to OARs could be got with lower jaw widths.The widened jaw widths resulted in reduced planned treatment time,decreased monitor units and gantry rotations,shortened gantry period while enhanced treatment efficiency.Conclusion A 2.5 cm jaw width for HT planning contributes to improving treatment efficiency during HCC SBRT under the premise of ensured target dose distribution and satisfactory dose to OAR for clinical require-ments.[Chinese Medical Equipment Journal,2024,45(7):51-55]

Activation of nuclear factor erythroid 2-related factor 2(Nrf2)by Kelch-like ECH-associated protein 1(Keap1)alkylation plays a central role in anti-inflammatory therapy.However,activators of Nrf2 through alkylation of Keap1-Kelch domain have not been identified.Deoxynyboquinone(DNQ)is a natural small molecule discovered from marine actinomycetes.The current study was designed to investigate the anti-inflammatory effects and molecular mechanisms of DNQ via alkylation of Keap1.DNQ exhibited signif-icant anti-inflammatory properties both in vitro and in vivo.The pharmacophore responsible for the anti-inflammatory properties of DNQ was determined to be the α,β-unsaturated amides moieties by a chemical reaction between DNQ and N-acetylcysteine.DNQ exerted anti-inflammatory effects through activation of Nrf2/ARE pathway.Keap1 was demonstrated to be the direct target of DNQ and bound with DNQ through conjugate addition reaction involving alkylation.The specific alkylation site of DNQ on Keap1 for Nrf2 activation was elucidated with a synthesized probe in conjunction with liquid chromatography-tandem mass spectrometry.DNQ triggered the ubiquitination and subsequent degra-dation of Keap1 by alkylation of the cysteine residue 489(Cys489)on Keap1-Kelch domain,ultimately enabling the activation of Nrf2.Our findings revealed that DNQ exhibited potent anti-inflammatory capacity through α,β-unsaturated amides moieties active group which specifically activated Nrf2 signal pathway via alkylation/ubiquitination of Keap1-Kelch domain,suggesting the potential values of targeting Cys489 on Keap1-Kelch domain by DNQ-like small molecules in inflammatory therapies.

Objective To evaluate the predictors of recurrent in-stent restenosis(R-ISR)occurrence in drug-eluting stents(DES).Methods A total of 201 patients with ISR who received percutaneous coronary intervention(PCI)surgery in the First Medical Center of the Chinese PLA General Hospital from January 2010 to August 2023 were selected as the study objects,and the patients were divided into R-ISR group and non-R-ISR group according to their post-discharge angiography review.The clinical baseline data and the features of interventional surgery during the first ISR-PCI were retrospectively analyzed.Results Among the 201 patients,168 were males and 33 were females,with an average age of(61.97±10.02)years.The median interval between initial and follow-up angiography was 1.5 years.Patients were divided into two groups based on their radiographic reviews:R-ISR group(98 patients and 104 ISR lesions)and non-R-ISR group(103 patients and 111 ISR lesions).Multivariate Logistic regression analysis showed that the incidence of R-ISR was correlated with Ostial disease(OR 2.987,95％CI 1.343-6.642,P=0.007),plain old balloon angioplasty(POBA)performed for ISR lesions(OR 3.081,95％CI 1.293-7.343,P=0.011)and the maximum diameter stenosis rate of ISR lesions before surgery(OR 1.016,95％CI 1.002-1.030,P=0.022).Conclusions In patients currently receiving interventional therapy for ISR,Ostial disease,POBA treatment for ISR disease,and maximum diameter stenosis rate of ISR disease were associated predictors of R-ISR development.