In order to solve the problems of difficult test, high cost and long cycle in the development of large-scale airborne negative pressure isolation system, the simulation analysis of negative pressure response characteristics is carried out around various aviation conditions such as aircraft ascending, leveling and descending, especially rapid decompression, based on the computational fluid dynamics (CFD) method. The results showed that the isolation cabin could achieve -50 Pa pressure difference environment and form a certain pressure gradient. The exhaust air volume reached the maximum value in the early stage of the aircraft's ascent, and gradually decreased with the increase of altitude until it was level flying. In the process of aircraft descent, the exhaust fan could theoretically maintain a pressure difference far below -50 Pa without working; Under the special condition of rapid pressure loss, it was difficult to deal with the rapid change of low pressure only by the exhaust fan, so it was necessary to design safety valve and other anti-leakage measures in the isolation cabin structure. Therefore, the initial stage of aircraft ascent is the key stage for the adjustment and control of the negative pressure isolation system. By controlling the exhaust air volume and adjusting parameters, it can adapt to the change of low pressure under normal flight conditions, form a relatively stable negative pressure environment, and meet the needs of biological control, isolation and transport.
Aircraft ; Computer Simulation ; Aviation/instrumentation* ; Humans ; Hydrodynamics ; Air Pressure ; Equipment Design ; Pressure

Objective:To analyze the time to reach full enteral feedings (TFEF) among preterm infants with gestational age (GA)<32 weeks admitted to the neonatal intensive care unit (NICU) of Chinese Neonatal Network (CHNN).Methods:This was a retrospective analysis based on the database from the CHNN 89 participating centers between January 1 st, 2019 and December 31 st, 2022. All 16 155 preterm infants with a GA <32 weeks and a birth weight <1 500 g, admitted to the NICU within 24 h after birth, hospitalization for at least 7 d and achieved full enteral feedings before discharge were included. According to the birth weight, these infants were divided into extremely low birth weight (ELBW) group and very low birth weight (VLBW) group. The practice characteristics of TFEF across different GA, the severity of neonatal admission, the NICU interventions before reaching full enteral feeding, and relevant neonatal diseases were described. Mann-Whitney U tests or Kruskal-Wallis H tests was used for comparison between groups. Results:Among the 16 155 preterm infants with a GA <32 weeks, 8 505 case (52.6%) were male. The TFEF in 3 374 cases of ELBW groups was 32 (22, 46) d, 351 cases (10.4%) with TFEF ≤2 weeks, 1 050 cases (31.1%) with TFEF >2-4 weeks, 964 cases (28.6%) with TFEF >4-6 weeks, and 1 009 cases (29.9%) with TFEF >6 weeks. The TFEF in 12 781 cases of VLBW group was 22 (15, 32) d, 439 cases (3.4%) with TFEF ≤1 week, 2 565 cases (20.1%) with TFEF >1-2 weeks, 5 526 cases (43.2%) with TFEF >2-4 weeks, and 4 251 cases (33.3%) with TFEF >4 weeks. The TFEF was 36(23, 52) d of 625 preterm infants at a GA ≤25 weeks and 20 (13, 28) d of 2 606 preterm infants at a GA 31 weeks. Inborn infants had a shorter TFEF than those outborn infants and the infants with breast-fed achieved shorter than formula and mixed feeding both in ELBW and VLBW groups (all P<0.001). The earlier enteral feeding started, the shorter TFEF will be both in ELBW and VLBW groups (both P<0.001). The TFEF of preterm infants who were treated before full enteral feeding like peripherally inserted central catheters, and blood transfusions and blood product providers were all longer than those who were not treated (all P<0.001). The TFEF of preterm infants with complications like hemodynamically significant patent ductus arteriosus, necrotizing enterocolitis, late onset sepsis, severe retinopathy of prematurity and bronchopulmonary dysplasia were all longer than those without (all P<0.001). Conclusions:The distribution of TFEF in VLBW and ELBW has a large difference. The TFEF of preterm infants varies with different GA, treatment measures and complications. Further quality improvement is required to shorten TFEF.

Objective:To establish 30-day of age transcutaneous bilirubin (TcB) reference curves for healthy neonates, and to investigate regional variations in bilirubin dynamics.Methods:A multicenter retrospective cohort study was conducted. A total of 220 950 healthy neonates born at a gestational age of 35-<42 weeks, with a birth weight ≥2 000 g, who did not receive phototherapy within 60 h after birth were recruited. All of them underwent remote TcB monitoring using the Bilibaby remote jaundice monitoring system between August 1 st, 2020 and December 31 st, 2024 in 426 hospitals. TcB data were collected within the period from birth to 30-day of age. The P40, P75, and P95 of TcB values were calculated, and dynamic TcB curves for 30-day of age were constructed. Patterns of bilirubin change, rates of change, and transition outcomes were described. Regional comparisons between South and North were conducted using linear mixed-effects models for TcB trajectories and Pearson′s chi-square test for outcome differences. Results:A total of 220 950 neonates were included, of whom 101 711 (46.03%) were female. Gestational age at birth was (38.75±1.12) weeks, and birth weight was (3 272±417) g. TcB levels increased rapidly within 3-day of age, peaked at 4-6-day of age, with peak values at P40, P75, and P95 of 200.6, 239.7 and 275.4 μmol/L (11.8, 14.1 and 16.2 mg/dl), respectively. TcB levels gradually declined thereafter and stabilized after 13-day of age, with values at P40, P75, and P95 fluctuating between 147.9-159.8, 190.4-200.6, and 231.2-239.7 μmol/L (8.7-9.4, 11.2-11.8, 13.6-14.1 mg/dl), respectively. Notably, among neonates categorized as low-or low-intermediate-risk within 3-day of age, 6 700 (12.76%) progressed to intermediate-high or high risk between 4 and 30 days of age. Before 13-day of age, TcB levels in the southern regions were consistently higher than those in the northern regions ( P=0.039); from 14 to 30 days of age, the overall TcB levels had no statistically difference, but the temporal changes in TcB still showed regional differences (degrees of freedom=3, all interaction P<0.05). Among neonates classified as low-or low-intermediate risk within 3-day of age, 25 326 were from southern regions, of whom 4 254 (16.80%) progressed to intermediate-high or high risk between 4 and 30 days of age. In northern regions, 27 193 neonates were classified as low-or low-intermediate risk within 3-day of age, among whom 2 446 (8.99%) progressed to intermediate-high or high risk. The risk progression between the 2 regions had statistically difference ( χ2=716.49, P<0.001). Conclusions:A TcB percentile curve for neonates within 30-day of age was established, revealing that both the overall TcB level and its temporal trend were higher in southern than in northern newborns. These findings provide baseline data to support continuous management of neonatal jaundice.

Phytochemicals are natural products derived from nature.Numerous studies have demonstrated that they can inhib-it the occurrence and development of different tumors through various pathways.Recent studies have revealed that the tumor microen-vironment is a key regulatory target that drives the malignant progression of tumors,and its synergistic anti-tumor effects with phyto-chemicals has become a research focus.Therefore,this article reviews the current status and progress of research on the role of phyto-chemicals in the tumor microenvironment and its possible mechanisms in recent years.

Phytochemicals are natural products derived from nature.Numerous studies have demonstrated that they can inhib-it the occurrence and development of different tumors through various pathways.Recent studies have revealed that the tumor microen-vironment is a key regulatory target that drives the malignant progression of tumors,and its synergistic anti-tumor effects with phyto-chemicals has become a research focus.Therefore,this article reviews the current status and progress of research on the role of phyto-chemicals in the tumor microenvironment and its possible mechanisms in recent years.

Objective:To analyze the time to reach full enteral feedings (TFEF) among preterm infants with gestational age (GA)<32 weeks admitted to the neonatal intensive care unit (NICU) of Chinese Neonatal Network (CHNN).Methods:This was a retrospective analysis based on the database from the CHNN 89 participating centers between January 1 st, 2019 and December 31 st, 2022. All 16 155 preterm infants with a GA <32 weeks and a birth weight <1 500 g, admitted to the NICU within 24 h after birth, hospitalization for at least 7 d and achieved full enteral feedings before discharge were included. According to the birth weight, these infants were divided into extremely low birth weight (ELBW) group and very low birth weight (VLBW) group. The practice characteristics of TFEF across different GA, the severity of neonatal admission, the NICU interventions before reaching full enteral feeding, and relevant neonatal diseases were described. Mann-Whitney U tests or Kruskal-Wallis H tests was used for comparison between groups. Results:Among the 16 155 preterm infants with a GA <32 weeks, 8 505 case (52.6%) were male. The TFEF in 3 374 cases of ELBW groups was 32 (22, 46) d, 351 cases (10.4%) with TFEF ≤2 weeks, 1 050 cases (31.1%) with TFEF >2-4 weeks, 964 cases (28.6%) with TFEF >4-6 weeks, and 1 009 cases (29.9%) with TFEF >6 weeks. The TFEF in 12 781 cases of VLBW group was 22 (15, 32) d, 439 cases (3.4%) with TFEF ≤1 week, 2 565 cases (20.1%) with TFEF >1-2 weeks, 5 526 cases (43.2%) with TFEF >2-4 weeks, and 4 251 cases (33.3%) with TFEF >4 weeks. The TFEF was 36(23, 52) d of 625 preterm infants at a GA ≤25 weeks and 20 (13, 28) d of 2 606 preterm infants at a GA 31 weeks. Inborn infants had a shorter TFEF than those outborn infants and the infants with breast-fed achieved shorter than formula and mixed feeding both in ELBW and VLBW groups (all P<0.001). The earlier enteral feeding started, the shorter TFEF will be both in ELBW and VLBW groups (both P<0.001). The TFEF of preterm infants who were treated before full enteral feeding like peripherally inserted central catheters, and blood transfusions and blood product providers were all longer than those who were not treated (all P<0.001). The TFEF of preterm infants with complications like hemodynamically significant patent ductus arteriosus, necrotizing enterocolitis, late onset sepsis, severe retinopathy of prematurity and bronchopulmonary dysplasia were all longer than those without (all P<0.001). Conclusions:The distribution of TFEF in VLBW and ELBW has a large difference. The TFEF of preterm infants varies with different GA, treatment measures and complications. Further quality improvement is required to shorten TFEF.

Objective:To establish 30-day of age transcutaneous bilirubin (TcB) reference curves for healthy neonates, and to investigate regional variations in bilirubin dynamics.Methods:A multicenter retrospective cohort study was conducted. A total of 220 950 healthy neonates born at a gestational age of 35-<42 weeks, with a birth weight ≥2 000 g, who did not receive phototherapy within 60 h after birth were recruited. All of them underwent remote TcB monitoring using the Bilibaby remote jaundice monitoring system between August 1 st, 2020 and December 31 st, 2024 in 426 hospitals. TcB data were collected within the period from birth to 30-day of age. The P40, P75, and P95 of TcB values were calculated, and dynamic TcB curves for 30-day of age were constructed. Patterns of bilirubin change, rates of change, and transition outcomes were described. Regional comparisons between South and North were conducted using linear mixed-effects models for TcB trajectories and Pearson′s chi-square test for outcome differences. Results:A total of 220 950 neonates were included, of whom 101 711 (46.03%) were female. Gestational age at birth was (38.75±1.12) weeks, and birth weight was (3 272±417) g. TcB levels increased rapidly within 3-day of age, peaked at 4-6-day of age, with peak values at P40, P75, and P95 of 200.6, 239.7 and 275.4 μmol/L (11.8, 14.1 and 16.2 mg/dl), respectively. TcB levels gradually declined thereafter and stabilized after 13-day of age, with values at P40, P75, and P95 fluctuating between 147.9-159.8, 190.4-200.6, and 231.2-239.7 μmol/L (8.7-9.4, 11.2-11.8, 13.6-14.1 mg/dl), respectively. Notably, among neonates categorized as low-or low-intermediate-risk within 3-day of age, 6 700 (12.76%) progressed to intermediate-high or high risk between 4 and 30 days of age. Before 13-day of age, TcB levels in the southern regions were consistently higher than those in the northern regions ( P=0.039); from 14 to 30 days of age, the overall TcB levels had no statistically difference, but the temporal changes in TcB still showed regional differences (degrees of freedom=3, all interaction P<0.05). Among neonates classified as low-or low-intermediate risk within 3-day of age, 25 326 were from southern regions, of whom 4 254 (16.80%) progressed to intermediate-high or high risk between 4 and 30 days of age. In northern regions, 27 193 neonates were classified as low-or low-intermediate risk within 3-day of age, among whom 2 446 (8.99%) progressed to intermediate-high or high risk. The risk progression between the 2 regions had statistically difference ( χ2=716.49, P<0.001). Conclusions:A TcB percentile curve for neonates within 30-day of age was established, revealing that both the overall TcB level and its temporal trend were higher in southern than in northern newborns. These findings provide baseline data to support continuous management of neonatal jaundice.

Objective To study the sedative and hypnotic effects of Yening Capsules and investigate its bioactive mechanism in mice.Methods The mice were randomly divided into control group,estazolam group(0.8 mg/kg),low,medium and high-dose Yening Capsules groups(400,600 and 800 mg/kg).The locomotor activity,latency to persistent sleep,sleep duration and sleep rate were determined respectively in mice via the open field test and injection of pentobarbital sodium in subthreshold and suprathreshold doses.The content of GABA,5-HT,DA and NE in brain tissue of mice were detected by enzyme-linked immunosorbent assay(ELISA).Results Compared with the control group,Yening Capsules medium and high dose group(P<0.05,P<0.01)significantly decreased the locomotor activity of mice.The sleep latency in Yening Capsules medium and high dose group were significantly shorten(P<0.05,P<0.05)and the sleep duration(P<0.05,P<0.01)were extended.The sleep rate of Yening Capsules medium and high dose groups(P<0.05,P<0.01)was significantly increased.Compared with the control group,high dose of Yening Capsules can significantly increase GABA(P<0.05),5-HT(P<0.05),DA(P<0.05),NE(P<0.01)in mouse brain tissue.Conclusion Yening Capsules had obvious sedative and hypnotic effects,and its mechanism may be related to the increasement of GABA,5-HT,DA and NE level in brain tissue of mice.

Objective:To study the clinical characteristics and risk factors of necrotizing enterocolitis (NEC) in one of the premature twins.Methods:A retrospective study was conducted on twin premature infants who were admitted to the Department of Neonatology at the Third Affiliated Hospital of Zhengzhou University from January 2017 to December 2022 and only one got NEC. The twins were divided into NEC group and control group, the clinical data were collected and analyzed by SPSS 26.0 statistical software.Results:This study enrolled 109 pairs of premature twins, 109 cases in the NEC group, and 109 cases in the control group. Univariate analysis showed that birth weight, pre NEC white blood cell count were lower in NEC group than those in the control group, while the proportion of smaller than gestational age (SGA), donor of twin-to-twin transfusion syndrome, feeding intolerance, incomplete enteral feeding, start feeding time >48 h, red blood cell transfusion 72 h before NEC onset and the neutrophils ratio were higher in the NEC group than that of the control group, the difference was statistically significant ( P<0.05). Multivariate logistic analysis showed that low birth weight ( OR=1.558, 95% CI1.197-2.142), SGA ( OR=1.721, 95% CI 1.217-2.536), feeding intolerance ( OR=3.798, 95% CI 1.347-10.706), and incomplete enteral feeding ( OR=4.319, 95% CI 1.673-11.149) were independent risk factors for NEC ( P<0.05). Conclusions:Low birth weight, small for gestational age, feeding intolerance, and incomplete enteral feeding are independent risk factors for NEC in one of the premature twins.

Objective:To summarize the clinical and genetic characteristics of children with Menkes disease(MD).Methods:The clinical manifestations, auxiliary examinations and genetic testing results of 15 MD children admitted to the Department of Pediatrics of the Third Affiliated Hospital of Zhengzhou University, Children′s Hospital Affiliated of Zhengzhou University and the First Affiliated Hospital of Zhengzhou University from June 2016 to October 2022 were analyzed retrospectively.These children were followed up.Results:All the 15 children were male.The age at onset was ranging from 9 days to 5.5 months.White skin, curly hair, skin laxity, hypotonia and severe developmental delay were found in all children, with epilepsy in 13 children, anemia in 11 children and granulocytopenia in 4 children.The concentration of ceruloplasmin in the serum of MD children was lower than that in healthy children of the same age.The concentration of ceruloplasmin in MD children younger than 3 months was significantly lower than that in healthy children of the same age and MD children older than 3 months.The brain magnetic resonance imaging showed abnormalities in all 15 children.Twelve children showed tortuous intracranial vessels in brain magnetic resonance angiography examinations.All the 15 children had ATP7A gene pathogenic variants, including 4 missense variants(2 cases with c. 2179G>A), 3 frameshift variants, 3 nonsense variants, 3 exon deletions and 2 splice site variants.Among these children, 1 had a novel gene variant that had not been reported so far(c.2968C>T). Conclusions:MD has early onset age and diverse clinical manifestations, but also has characteristic clinical manifestations and applicable auxiliary examinations.Its diagnosis depends on genetic testing.The c. 2179G>A and exon deletions may be hot mutations in Chinese MD patients.