Objective To investigate the impact of lower inspiratory peak flow rates on airway peak pressure when using a ventilator to maintain respiratory function during the advanced life support phase of in-hospital cardiopulmonary resuscitation(CPR).Methods A prospective study was conducted,30 patients who underwent CPR for more than 20 minutes admitted to Lishui Municipal Central Hospital between September 2021 and December 2023 were enrolled as the study subjects.Volume controlled ventilation(VCV)with a descending flow waveform was used,while other preset parameters remained unchanged.Airway peak pressure was measured at different peak flow rates(55,50,45,and 40 L/min).The influence of varying flow rates on peak pressure was analyzed.Results During CPR,patients were in a continuous state of chest compressions.When the ventilator parameters were set conventionally,alarms for high airway pressure,low tidal volume(VT),and high respiratory rate often occurred,which affected the effectiveness of ventilatory support.There was a significant variation in airway peak pressure among different patients.As the peak flow rate increased from 40 L/min to 55 L/min,the airway peak pressure gradually increased.During the process of reducing the peak flow rate,the pulse oxygen saturation(SpO2)of all patients remained stable without significant changes.The 40 L/min group had significantly lower peak pressures than the 50 and 55 L/min groups,whereas the 55 L/min group had significantly higher pressures than all others[cmH2O(1 cmH2O≈0.098 kPa):41.20±9.06 vs.47.90±9.04 and 53.70±7.96,all P<0.05].When comparing patients with peak flow rates of 40 L/min and 50 L/min,as well as 45 L/min and 55 L/min,the average airway peak pressure increased significantly with each 10 L/min increment in inspiratory peak flow rate.However,the SpO2 remained essentially unchanged or slightly increased as the peak flow rate decreased.There were no statistically significant differences in SpO2 among patients at different peak flow rate levels.When the peak flow rate was set at 55,50,45,and 40 L/min,the proportions of patients with airway peak pressure>40 cmH2O were 100.0%,83.3%,63.3%,and 53.3%,respectively.Among them,the proportions of patients with airway peak pressure>50 cmH2O were 66.7%,40.0%,16.6%,and 16.6%,respectively.As the peak flow rate decreased,the proportion of patients with airway peak pressure>40 cmH2O gradually decreased.If the peak flow rate was set at 45 L/min or lower,the number of patients with airway peak pressure>50 cmH2O during CPR was less than 50.0%of the total number of cases.Conclusions During mechanical ventilation in CPR,using volume-controlled ventilation(VCV)mode with a decelerating waveform,improper peak flow rate settings can easily trigger high airway pressure alarms and result in low tidal volume(VT),leading to poor synchrony between the ventilator and the patient.Compared to peak flow rates of 55 L/min and above,selecting an inspiratory peak flow rate of 40 L/min and setting the high-pressure alarm at 50 cmH2O is suitable for the mechanical ventilation needs of most patients and does not affect oxygenation levels.This is a more appropriate choice.

Objective To investigate the impact of lower inspiratory peak flow rates on airway peak pressure when using a ventilator to maintain respiratory function during the advanced life support phase of in-hospital cardiopulmonary resuscitation(CPR).Methods A prospective study was conducted,30 patients who underwent CPR for more than 20 minutes admitted to Lishui Municipal Central Hospital between September 2021 and December 2023 were enrolled as the study subjects.Volume controlled ventilation(VCV)with a descending flow waveform was used,while other preset parameters remained unchanged.Airway peak pressure was measured at different peak flow rates(55,50,45,and 40 L/min).The influence of varying flow rates on peak pressure was analyzed.Results During CPR,patients were in a continuous state of chest compressions.When the ventilator parameters were set conventionally,alarms for high airway pressure,low tidal volume(VT),and high respiratory rate often occurred,which affected the effectiveness of ventilatory support.There was a significant variation in airway peak pressure among different patients.As the peak flow rate increased from 40 L/min to 55 L/min,the airway peak pressure gradually increased.During the process of reducing the peak flow rate,the pulse oxygen saturation(SpO2)of all patients remained stable without significant changes.The 40 L/min group had significantly lower peak pressures than the 50 and 55 L/min groups,whereas the 55 L/min group had significantly higher pressures than all others[cmH2O(1 cmH2O≈0.098 kPa):41.20±9.06 vs.47.90±9.04 and 53.70±7.96,all P<0.05].When comparing patients with peak flow rates of 40 L/min and 50 L/min,as well as 45 L/min and 55 L/min,the average airway peak pressure increased significantly with each 10 L/min increment in inspiratory peak flow rate.However,the SpO2 remained essentially unchanged or slightly increased as the peak flow rate decreased.There were no statistically significant differences in SpO2 among patients at different peak flow rate levels.When the peak flow rate was set at 55,50,45,and 40 L/min,the proportions of patients with airway peak pressure>40 cmH2O were 100.0%,83.3%,63.3%,and 53.3%,respectively.Among them,the proportions of patients with airway peak pressure>50 cmH2O were 66.7%,40.0%,16.6%,and 16.6%,respectively.As the peak flow rate decreased,the proportion of patients with airway peak pressure>40 cmH2O gradually decreased.If the peak flow rate was set at 45 L/min or lower,the number of patients with airway peak pressure>50 cmH2O during CPR was less than 50.0%of the total number of cases.Conclusions During mechanical ventilation in CPR,using volume-controlled ventilation(VCV)mode with a decelerating waveform,improper peak flow rate settings can easily trigger high airway pressure alarms and result in low tidal volume(VT),leading to poor synchrony between the ventilator and the patient.Compared to peak flow rates of 55 L/min and above,selecting an inspiratory peak flow rate of 40 L/min and setting the high-pressure alarm at 50 cmH2O is suitable for the mechanical ventilation needs of most patients and does not affect oxygenation levels.This is a more appropriate choice.

Background Bacteria are the most diverse and widely sourced microorganisms in the indoor air of subway stations, where pathogenic bacteria can spread through the air, leading to increased health risks. Objective To understand the status and distribution characteristics of indoor air bacterial pollution in subway stations and compartments in a city of Central South China, and to provide a scientific basis for formulating intervention measures to address indoor air bacteria pollution in subways. Methods Three subway stations and the compartments of trains parking there in a city in Central South China were selected according to passenger flow for synchronous air sampling and monitoring. Temperature, humidity, wind speed, carbon dioxide (CO₂), fine particulate matter (PM_2.5), and inhalable particulate matter (PM₁₀) were measured by direct reading method. In accordance with the requirements of Examination methods for public places-Part 3: Airborne microorganisms (GB/T 18204.3-2013), air samples were collected at a flow rate of 28.3 L·min⁻¹, and total bacterial count was estimated. Bacterial microbial species were identified with a mass spectrometer and pathogenic bacteria were distinguished from non-pathogenic bacteria according to the Catalogue of pathogenic microorganisms transmitted to human beings issued by National Health Commission. Kruskal-Wallis H test was used to compare the subway hygiene indicators in different regions and time periods, and Bonferroni test was used for pairwise comparison. Spearman correlation test was used to evaluate the correlation between CO₂ concentration and total bacterial count. Results The pass rates were 100.0% for airborne total bacteria count, PM_2.5, and PM₁₀ in the subway stations and train compartments, 94.4% for temperature and wind speed, 98.6% for CO₂, but 0% for humidity. The overall median (P₂₅, P₇₅) total bacteria count was 177 (138,262) CFU·m⁻³. Specifically, the total bacteria count was higher in station halls than in platforms, and higher during morning peak hours than during evening peak hours (P<0.05). A total of 874 strains and 82 species were identified by automatic microbial mass spectrometry. The results of identification were all over 9 points, and the predominant bacteria in the air were Micrococcus luteus (52.2%) and Staphylococcus hominis (9.8%). Three pathogens, Acinetobacter baumannii (0.3%), Corynebacterium striatum (0.1%), and Staphylococcus epidermidis bacilli (2.2%) were detected in 23 samples (2.6%), and the associated locations were mainly distributed in train compartments during evening rush hours. Conclusion The total bacteria count in indoor air varies by monitoring sites of subway stations and time periods, and there is a risk of opportunistic bacterial infection. Attention should be paid to cleaning and disinfection during peak passenger flow hours in all areas.

Objective:A nested-PCR assay is developed to detect and identify the genomic DNA of Brucella vaccine A19 strain. Methods:The whole genomic sequences of Brucella vaccine A19 strain and other Brucella spp. strains were compared and analyzed. The primers were designed by nucleotide difference sites. The nested-PCR assay was established to detect and identify Brucella vaccine A19 strain. The genomic DNA of Brucella vaccine A19 strain was extracted and diluted. The diluted template DNA was tested for sensitivity of using nested-PCR assay. And the specificity of nested-PCR assay was tested for the genomic DNA of other Brucella spp. strains and non- Brucella spp. strains. Results:The minimum detection limit of the nested-PCR assay was 3.43 fg. The nested-PCR assay established for amplification of Brucella vaccine A19 strain showed 246 bp electrophoresis bands, while other Brucella spp. strains showed 314 bp electrophoresis bands, and non- Brucella spp. strains did not produce electrophoresis bands. Conclusions:The nested-PCR assay established has the characteristics of high sensitivity and specificity. It can be detected when there is one copy of Brucella vaccine A19 strain genomic DNA in the reaction system. This method is particularly suitable for the detection and identification of trace genomic DNA of Brucella vaccine A19 strain in sample.

Objective:To establish a quantitative real-time PCR detection system for Brucella S2 vaccine strain. Methods:Based on the differences in the entire genome sequence between Brucella S2 vaccine strain and other reference strains of Brucella, primers and probes were designed to establish a quantitative real-time PCR detection system for Brucella S2 vaccine strain. The DNA of 22 reference strains of Brucella and 8 non- Brucella control strains were obtained from the National Institute for Infectious Disease Control and Prevention of the Chinese Center for Disease Control and Prevention. At the same time, environmental samples were obtained from the brucellosis vaccine manufacturers, and bacterial DNA from environmental samples was extracted using a blood/tissue genomic DNA extraction kit. The obtained DNA was pre-amplified by conventional PCR, and then subjected to quantitative real-time PCR secondary amplification (nested fluorescence quantitative PCR) using the amplified PCR product as a template. The specific fluorescence curve and corresponding number of cycles (Ct value) were observed, and the sensitivity was tested. Results:The quantitative real-time PCR detection system established did not detect specific fluorescence curves (without Ct values) for 21 reference strains of Brucella and 8 non- Brucella control strains, except for S2 vaccine strains. The established detection system had a minimum detection limit of 4.34 fg (genomic DNA) for detecting the DNA of Brucella S2 vaccine strain; DNA of Brucella S2 vaccine strain was detected in 3 of the 14 environmental samples collected. Conclusion:The quantitative real-time PCR detection system established can detect Brucella S2 vaccine strain in samples, with good sensitivity and specificity.

Objective: To analyze the etiological characteristics of an outbreak of Campylobacter foodborne disease in a middle school in Suzhou City, so as to provide insights into the identification of pathogenic factors of Campylobacter foodborne disease outbreaks. Methods: Eighteen anal swabs from patients, 10 anal swabs from canteen workers, 43 food samples, 2 drinking water samples, 2 food original material samples and 31 environmental samples were collected, and the pathogens were rapidly screened using the gastrointestinal infection detection strip. The pathogens were isolated and cultured using the double-pore filtration membrane method, and cluster analysis of bacterial isolates was performed using pulsed field gel electrophoresis ( PFGE ). In addition, the susceptibility of Campylobacter isolates to antibiotics was tested using the Campylobacter agar dilution method. Results: A total of 63 cases with Campylobacter infections were reported, and the major clinical symptoms included diarrhea ( 51 cases, 80.95% ) and fever ( 39 cases, 61.90% ), while no inpatients or deaths were found. Twelve Campylobacter-positive samples were detected, including 11 anal swabs sampled from patients and one food original material sample. Among the 11 positive anal swabs, there were 10 samples positive for Campylobacter jejuni and one sample positive for C. coli, and of the one positive food original material, C. coli was identified. PFGE analysis showed that 10 C. jejuni isolates of had 100.0% homology, and these 10 isolates were 100.0% resistant to naphthyridic acid, ciprofloxacin and tetracycline, appearing multidrug resistance. Conclusions This is an outbreak of foodborne disease caused by C. jejuni infections. Gastrointestinal infection detection strips, double-pore filtration membrane and PFGE typing are rapid and accurate to identify pathogenic factors.

A case of Usher syndrome with methylmalonic acidemia and homocysteine is reported. The patient was a two-month-old and small for gestational age male infant hospitalized for "feeding difficulties" during the neonatal period. The baby boy presented hypotonia, microcephaly, and hearing loss after birth. Genetic test found compound heterozygous mutations of c.482G>A and c.567dup in MMACHC, and both were pathogenic mutations inherited from his parents. Moreover, the patient also had compound heterozygous variants at c.2802T>G and c.14017T>C of USH2A gene. The former was suspected to be pathogenic, and the latter was of unknown clinical significance. Both were from the parents. Usher syndrome and methylmalonic acidemia with homocysteine were clinically diagnosed. Followed up to the age of two, the child was found with moderate mental retardation, while the physical development was comparable to that of the same age group.

Objective:To introduce our experience on dealing with the internal carotid artery (ICA) during the resection of lateral skull base tumors, and to explore the reference values for using radiological findings to make a rational surgical plan.Methods:A retrospective study of patients who underwent resection of lateral skull base tumors involving ICA at Peking Union Medical College Hospital from May 2015 to May 2021 was conducted. The demographic information, preoperative examinations, diagnosis, surgical details and follow-ups were collected. A total of 41 patients were enrolled [24 (58.5%] females, 17 (41.5%) males], with an average age of 47.9 years. According to the preoperative imaging findings, the relationships between the tumors and ICA were divided into four types: adjacency, compression, invasion and ICA aneurysm.Results:The ICA was preserved in 32 (78.0%, 32/41) cases and was reconstructed in nine (22.0%, 9/41) cases. All the 27 (65.9%, 27/41) tumors adjacent to ICA were successfully separated from the artery. Among the 11 tumors compressing the ICA, six were resected with the involved ICA segment and vascular reconstruction was conducted. One (2.4%, 1/41) tumor invading ICA and two (4.9%, 2/41) ICA aneurysms required revascularization. The mean follow-up time was (26.1±2.9) months. There was no recurrence, except one case of adenoid cystic carcinoma which had brain metastases one year after surgery.Conclusions:According to the preoperative imaging, lateral skull base tumors adjacent to ICA can be detached from the vascular surface. Separation should be attempted first for tumors compressing ICA, and revascularization should be followed if separation failed. Vascular reconstruction is usually needed in the removal of tumors invading ICA and ICA aneurysms. Preoperative radiology can provide good references for planning a surgery for lateral skull base tumors.

Here,we reported a case of term infant with unilateral congenital microphthalmia (CM).Physical examination conducted on 2 d after birth showed that the left eye was barely open and the eye socket was deeper than the right.Meanwhile,the cornea of the left eye was not completely exposed and the light reflex could not be elicited.Ophthalmology consultation,ultrasound and CT scan were conducted,and CM was finally diagnosed since the infant was found to have a small eyeball and shortened axial length,accompanying by pathological changes in the lens,vitreous body and retina.This case suggested that detailed physical examination should be carried out,especially for the eyes,including orbit and eyelid,presence or absence of secretion or concealed eyeball,together with medical imaging techniques technology,to ensure an early detection and diagnosis of CM in neonates.

In this study, we established a rapid and efficient HPLC method to determine the accumulation of Huperzine A and Huperzine B in the fermentation broth of endophytic fungus Colletotrichum gloesporioides from Huperzia serrate. The chloroform extracts of fermentation broth were dissolved in methanol and filtered before injection for HPLC analysis. The analysis was performed on an Agilent Eclipse plus-C18 column (250 mm×4.6 mm, 5 μm) by isocratic elution. The mobile phase was 0.015 mol/L ammonium acetate-methanol (70:30, V/V), the flow rate was 1 mL/min and the detection wavelength was set at 308 nm. Huperzine A and Huperzine B could be well separated within 25 min. Good linearity of Huperzine A was found in the range of 1.50-48.00 μg/mL (r=0.999 5), and that of huperzine B was in 0.25-7.50 μg/mL (r=0.999 7). The average recoveries of Huperzine A and Huperzine B were 106.83% and 108.06%, respectively (RSD=3.34%, 3.60%). The results demonstrate that this method can detect the content of huperzine A and huperzine B in fermentation broth simply, rapidly, accurately and in good reproducibility. Under the optimized conditions, the accumulated content of huperzine A and huperzine B were measured from the sixth to the fifteenth day. Huperzine A and Huperzine B reached the highest (12.417 0 μg/mL and 4.660 3 μg/mL, respectively) at the fourteenth and eighth days. The analysis methodology could contribute to the future study of huperzine A and huperzine B biosynthesis in C. gloeosporioides, consequently facilitate the development of new drug resources.