Objective To investigate the epidemiological characteristics and risk factors of hyperhomocysteinemia(HHcy)in military aircrew.Methods A retrospective study was conducted on 506 aircrew convalescents undergoing health examination from September 2023 to April 2024.Demographic,lifestyle,and biochemical data were analyzed.The risk factors of HHcy were identified by x2 test and multivariate Logistic regression.Results The HHcy detection rate was 21.94%(111/506),with a median homocysteine(Hcy)level of 11.75(9.70-14.30)μmol/L.Multivariate analysis revealed that smoking(OR=2.093,95%CI:1.313-3.336),service in conventional fighter aircraft(OR=1.716,95%CI:1.063-2.770),elevated low-density lipoprotein cholesterol(LDL-C)(OR=2.510,95%CI:1.413-4.458),and elevated bilirubin(OR=2.360,95%CI:1.509-3.691)were independent risk factors for HHcy(all P<0.05).Conclusion There is a high prevalence of HHcy in military pilots.It is strongly associated with smoking,aircraft type,and metabolic abnormalities.It is recommended to incorporate Hcy testing into routine physical examination,implement risk factor-based stratified interventions,and establish an atherosclerotic cardiovascular diseases early warning system integrating vascular imaging and risk assessment,aiming to reduce cardiovascular risks and safeguard combat effectiveness.

Objective To analyze the current research on cardiovascular diseases in pilots using bibliometric methods,so as to provide reference for future researches.Methods Articles indexed by China National Knowledge Infrastructure(CNKI)were selected as the research objects.The time window ranged from January 1990 to February 2024,and the keywords"pilot or flight personnel"and"cardiovascular"were selected to search for all published literatures on cardiovascular diseases in pilots.CiteSpace 6.1.R6 software was used to analyze the authors,institutions,and keywords of the included literatures,and a visual analysis graph was drawn.Results A total of 198 articles were included in this study.The journal with the most published articles was the Chinese Journal of Aerospace Medicine and Aviation Military Medicine.The author with the most published articles was Wang Lujin,followed by Zheng Jun.The institution with the most published articles was Air Force General Hospital(Air Force Medical Center).Risk factors,hypertension,and health assessment were hot keywords.The emerging word was medical appraisal.Conclusion The literatures of cardiovascular diseases among pilots are mainly published in aviation medical journals,forming a research team led by Wang Lujin and Zheng Jun.Research cooperation is mainly within the research team members,with less cooperation between research institutions.The research hotspots are risk factors of cardiovascular disease,hypertension,and health identification,and the forefront of research is the medical identification of cardiovascular diseases among pilots.With the increasing importance of cardiovascular diseases among pilots,it is necessary to strengthen cooperation among research institutions in the future,promote high-quality development in this field,and focus on strengthening scientific research in the prevention of cardiovascular diseases to maintain the physical and mental health of pilots.

Objective:In order to explore the impact of corona virus disease 2019(COVID-19)on the hospitalization of children with bronchiolitis and to improve clinicians′ understanding of the characteristics of bronchiolitis during the COVID-19 epidemic.Methods:This was a multicenter clinical study, and the data have been collected from 23 children′s medical centers in China.All the clinical data were retrospectively collected from children with bronchiolitis who were hospitalized at each study center from January 1, 2019 to December 31, 2021.The results included gender, age at hospitalization, length of stay, respiratory syncytial virus(RSV) test results, severity rating, ICU treatment, and the total number of children hospitalized with respiratory tract infection during the same period.The clinical data of children with bronchiolitis in 2019 before COVID-19 epidemic and in 2020、2021 during COVID-19 epidemic were statistically analyzed and compared.Results:According to a summary of data provided by 23 children′s medical centers, there were 4 909 cases of bronchiolitis in 2019, 2 654 cases in 2020, and 3 500 cases in 2021.Compared with 2019, the number of bronchiolitis cases decreased by 45.94% in 2020 and 28.70% in 2021.In 2019, 2020 and 2021, there were no significant differences in gender ratio, age, and duration of hospitalization.Compared with 2019, the ratio of bronchiolitis to the total number of hospitalizations for respiratory tract infection decreased significantly in 2020 and 2021( χ2=12.762, P<0.05; χ2=84.845, P<0.05).The proportion of moderate to severe bronchiolitis cases in both 2020 and 2021 was lower than that in 2019, and the difference was statistically significant ( χ2=4.054, P<0.05; χ2=8.109, P<0.05).There was no statistically significant difference in the proportion of bronchiolitis cases requiring ICU treatment between 2019, 2020, and 2021 ( χ2=1.914, P>0.05).In 2019, a total of 52.60%(2 582/4 909) of children with bronchiolitis underwent RSV pathogen testing, and among them, there were 708 cases with RSV positive, accounting for 28.00%.In 2020, 54.14%(1 437/2 654) of children with bronchiolitis underwent RSV pathogen testing, and there were 403 cases with RSV positive, accounting for 28.04%.In 2021, 66.80%(2 238/3 500) of children with bronchiolitis underwent RSV pathogen testing, and there were 935 cases with RSV positive, accounting for 41.78%.Compared with 2019 and 2020, the RSV positive rate in 2021 showed a significant increase( χ2=99.673, P<0.05; χ2=71.292, P<0.05). Conclusion:During the COVID-19 epidemic, the implementation of epidemic prevention and control measures reduced the hospitalization rate and severity of bronchiolitis, but did not reduce the positive rate of RSV detection.

Hypoxemia is a common complication of pneumonia, asthma, and bronchopulmonary dysplasia in children.Rapid identification of hypoxemia is of great significance for the disposal and management of critical children.Pulse oximetry is recognized by the World Health Organization as the best way to monitor hypoxemia in children, and it can monitor pulse oxygen saturation noninvasively and continuously.Based on the related literature at home and abroad, combined with the clinical needs of pediatrics, the " Expert consensus on clinical application of pulse oximetry in children" is formulated to improve the understanding of pediatricians and nurses on the application in pediatric clinical practice, principle, operation techniques, and limitations of pulse oximetry.

Objective:To investigate the knowledge, attitudes, and practices (KAP) of pulse oximetry among pediatric healthcare providers in China and analyze the factor influencing the KAP.Methods:A self-developed questionnaire was used for an online research on the KAP of 11 849 pediatric healthcare providers from 31 provinces, autonomous regions, and municipalities of China from March 11 to 14, 2022.The factors influencing the KAP of pulse oximetry among pediatric healthcare providers were examined by Logistic regression. Results:The scores of KAP, of pulse oximetry were 5.57±0.96, 11.24±1.25 and 11.19±4.54, respectively.The corresponding scoring rates were 69.61%, 74.95%, and 55.99%, respectively. Logistic regression results showed that the gender and working years of pediatric healthcare providers, the region they were located, and whether their medical institution was equipped with pulse oximeters were the main factors affecting the knowledge score (all P<0.05). Main factors influencing the attitude score of pediatric healthcare providers included their knowledge score, gender, educational background, working years, region, medical institution level, and whether the medical institution was equipped with pulse oximeters (all P<0.05). For the practice score, the main influencing factors were the knowledge score, gender, age, and whether the medi-cal institution was equipped with pulse oximeters (all P<0.05). Conclusions:Chinese pediatric healthcare providers need to further improve their knowledge about and attitudes towards pulse oximetry.Pulse oximeters are evidently under-used.It is urgent to formulate policies or guidelines, strengthen education and training, improve knowledge and attitudes, equip more institutions with pulse oximeters, and popularize their application in medical institutions.

Objective:To investigate the role of Sestrin2 overexpression in regulating mitochondrial fission and its mechanism in human neuroblastoma SH-SY5Y cell model of glucose and oxygen deprivation/recovery (OGD/R). Methods:(1) SH-SY5Y cells were divided into normal control group, OGD/R group, Vector group, and Sestrin2 overexpression group; Sestrin2 overexpression or empty vector stable cell lines in the Sestrin2 overexpression group and Vector group were constructed by lentivirus infection; cells in the later 3 groups were subjected to oxygen-glucose deprivation (OGD) for 4 h followed by restoration of O 2 supply for 18 h. The cell survival rate was detected by cell counting kit (CCK)-8 assay. The protein levels of Sestrin2, dynamin-related protein 1 (Drp1), mitochondrial fission protein 1 (Fis1), B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), Kelch-like ECH-related protein 1 (Keap1) in the cytoplasm and nuclear factor E2-related factor (Nrf2) in the nucleus were detected by Western blotting. The mitochondria ultrastructure was observed by transmission electron microscope. The Nrf2 nuclear translocation was detected by immunofluorescence staining. (2) Cell lines with Sestrin2 overexpression were divided into Sestrin2 overexpression group, Brusatol+ Sestrin2 overexpression group, and DMSO+ Sestrin2 overexpression group. Cells in the Brusatol+ Sestrin2 overexpression group were pretreated with normal medium containing Brusatol (Keap1/Nrf2 pathway inhibitor, final concentration: 100 nmol/L) for 4 h before OGD/R; cells in the DMSO+ Sestrin2 group were pretreated with normal medium containing DMSO (final volume fraction: 0.1%) for 4 h before OGD/R. Cells in these groups were then subjected to OGD for 4 h followed by restoration of O 2 supply for 18 h. The protein levels of Drp1, Fis1, Keap1 in the cytoplasm, and Nrf2 in the nucleus were measured by Western blotting. Results:(1) As compared with those in the OGD/R group, cells in the Sestrin2 overexpression group had significantly increased survival rate (61.33%±1.15% vs. 81.00%±3.00%), significantly up-regulated Bcl-2/Bax ratio (0.467±0.006 vs. 0.880±0.010), significantly decreased Drp1, Fis1 and cytoplasmic Keap1 protein levels (1.089±0.033 vs. 0.865±0.014; 0.829±0.009 vs. 0.350±0.007; 0.967±0.017 vs. 0.881±0.024), and significantly up-regulated nuclear Nrf2 protein level (0.627±0.025 vs. 0.957±0.015, P<0.05). The mitochondrial structure in the Sestrin2 overexpression group under electron microscope was more complete than that in the OGD/R group, and obvious nuclear translocation of Nrf2 was noted. (2) As compared with the Sestrin2 overexpression group, Brusatol+ Sestrin2 overexpression group had significantly decreased nuclear Nrf2 protein level (0.920±0.013 vs. 0.627±0.035), and statistically increased Drp1 and Fis1 protein levels (0.994±0.020 vs. 1.084±0.005; 0.728±0.010 vs. 0.906±0.022, P<0.05). Conclusion:Sestrin2 overexpression could suppress mitochondrial fission, reduce cell apoptosis, and attenuate OGD/R injury of SH-SY5Y cells by activating Keap1/Nrf2 pathway via down-regulating cytoplasmic Keap1 protein level and promoting Nrf2 nuclear translocation.

Objective To investigate the distribution characteristics and risk factors of intracranial and extracranial aterial lesions in Chinese patients with ischemic stroke . Methods In this multi‐center study ,2 310 continuously inpatients with ischemic stroke diagnosed in 20 stroke screening and prevention project base hospitals from June 2015 to M ay 2016 were enrolled . Carotid ultrasonography and transcranial color‐coded sonography or transcranial Doppler were performed in all patients to confirm the presence of cerebral artery stenosis or occlusion . According to the distribution of lesions ,the subjects were divided into 2 groups :the simple intracranial artery stenosis group and the simple extracranial artery stenosis group . T he difference of risk factors between the two groups was compared . Results Of the 2 310 patients with ischemic stroke ,1 516 ( 65 .6% ) had simple intracranial artery stenosis and 794 ( 34 .4% ) had simple extracranial artery stenosis . T he incidence of anterior circulation artery stenosis was higher in the group of intracranial artery stenosis than that in the extracranial artery stenosis group ( 68 .1% vs 48 .7% , P ＜0 .001) . Posterior circulation artery stenosis and combined anterior with posterior circulation artery stenosis were more common in patients with extracranial artery stenosis group than those in intracranial artery stenosis group ( 36 .4% vs 22 .1% ,14 .9% vs 9 .8% ;all P ＜0 .001) . Univariate analysis of risk factors for stroke showed that patients with intracranial arterial stenosis had a higher prevelence of hypertension , diabetes ,obesity ,and family history of stroke ,and their systolic blood pressure ,diastolic blood pressure , body mass index ( BM I) ,fasting blood‐glucose ,glycosylated hemoglobin ,triacylglycerol ,total cholesterol , and low‐density lipoprotein cholesterol were significantly higher than those in the extracranial arterial stenosis group ( all P ＜ 0 .05 ) . T he proportion of elderly ( ≥ 65 years old ) ,male and smokers in the extracranial arterial stenosis group was significantly higher than that in the intracranial arterial stenosis group ( all P ＜0 .05) . Multivariate logistic regression analysis showed that elderly ( ≥65 years old) ,male , and smoking history were independent risk factors for extracranial arterial stenosis ( OR＝ 2 .012 ,1 .637 , 1 .325 ,respectively ;all P ＜0 .05) . While hypertension ,diabetes ,less physical activity ,and high BM I levels were independent risk factors for simple intracranial arterial disease ( OR ＝ 1 .301 ,1 .252 ,1 .248 ,1 .030 , respectively ;all P ＜0 .05) . Conclusions There are significant differences in the distribution characteristics and risk factors of intracranial and extracranial aterial lesions in patients with ischemic stroke in China .

Objective To investigate the protective role of Sestrin2 overexpression in hypoxia and re-oxygenation injury (H/R) injury of hippocampal neurons and its mechanism in rats.Methods Neurons were enzymatically isolated from hippocampi of newborn Sprague-Dawley rats (less than 24 h old) and culturedinvitro. These neurons were randomly assigned into 4 groups (n=20) using a random number table: control group, H/R group, vector group and Sestrin2 overexpression group. The hippocampal neurons were seeded in 6-well plates at a density of 2×104 cells/mL; neurons in the latter two groups were transfected with lentiviruses containing empty vector andSestrin2overexpressed genes, respectively; the hippocampal neurons in the later three groups were subjected to oxygen-glucose deprivation (OGD) for 6 h followed by restoration of O2 supply for 20 h. The reactive oxygen species (ROS) content was detected by Reactive Species Assay Kit, and the ATP concentration was detected by ATP Assay Kit. Cell apoptosis rates were measured by flow cytometry. The levels of Sestrin2, dynamin-related protein 1 (Drp1), Fis1, and apoptosis-related proteins Bcl-2, Bax and cytochrome C (Cyt C) were measured by Western blotting. The ratio of Bcl-2 to Bax was calculated. The ultrastructure of mitochondria was observed by transmission electron microscopy.Results As compared with control group, H/R group had significantly lower ATP concentration, Bcl-2 protein expression and ratio of Bcl-2 to Bax ([11.15±0.42] nmol/mg proteinvs. [5.30±0.39] nmol/mg protein; 2.20±0.26vs. 0.91±0.02; 6.46± 0.41vs. 1.04±0.05), statistically higher average fluorescence intensity of ROS and cell apoptosis rate (152.41±17.38vs. 1530.00±14.69; 3.77％±0.74％vs. 56.57％±1.35％), and significantly higher protein levels of Sestrin2, Drp1, Fis1, Bax and Cyt C (0.66±0.06vs. 1.11±0.20; 0.48±0.03vs. 1.16±0.07; 1.14± 0.09vs. 2.47±0.09; 0.34±0.03vs. 0.88±0.04; 0.17±0.03vs. 0.30±0.03,P<0.05); what's more, the structure of mitochondria was obviously destroyed in I/R group. As compared with H/R group, Sestrin2 overexpression group had significantly increased ATP concentration, Sestrin2 and Bcl-2 protein expressions and ratio of Bcl-2 to Bax ([8.95±0.27] nmol/mg protein; 2.67±0.07; 1.80±0.19; 3.95±0.28), significantly lower average fluorescence intensity of ROS and cell apoptosis rate (337.27±15.32; 10.33％±2.60％), and statistically lower protein levels of Drp1, Fis1, Bax and Cyt C (0.43±0.02; 1.11±0.08; 0.45± 0.02; 0.17±0.02,P<0.05); the structure of mitochondria was relatively completed in Sestrin2 overexpression group.Conclusion Sestrin2 overexpression can inhibit mitochondrial fission, reduce accumulation of reactive oxygen species, improve mitochondrial energy metabolism and block mitochondria mediated apoptosis pathway, thereby alleviating I/R injury of rat hippocampal neurons.

Objective To evaluate and analyze the performance of Mindray BC-5D hematological control materials.Methods First, uniformity and stability tests were performed by using the Mindray BC5300 hematological analyzer.Then, the Mindray BC5300 hematological analyzer and the Coulter LH780 hematological analyzer were used simultaneously for the detection of Mindray BC-5D.The Coulter 5C hematological control materials and the domestic analyzer were used and replaced with new batches every month, to detect hematological control materials once for a succession of 6 months.Finally, the stability of the 3 hematological control materials from the 6 batches was compared accordingly.Results The uniformity of Mindray BC-5D hematological control materials met the na-tional requirements of the Pharmaceutical Industry Standards of the People′s Republic of China for whole blood quality control materials. Within the 90-day expiry date as specified by the manufacturer, no statistical significance could be seen in the short-term stability, mid-term stability and long-term stability, when comparisons were made between them(P>0.05).Therefore it conformed to the 14-day sta-bility requirements as declared by the manufacturer, once it was opened.The results of comparison for the stability of the 3 brands of hematological control materials were that the stability of Mindray BC-5D hematological control materials was similar to the Coulter 5C he-matological control materials, but was obviously superior to the control materials by the domestic analyzer.Conclusion The perform-ance of Mindray BC-5D hematological control materials was of better quality, more economical and had better clinical efficacy, which was worth further clinical extension.

Biochemistry is one of the important basic subjects in medical college. It is hard for students to master because of its complicated theories and abstract contents. It has been found that carrying out case-teaching method in biochemistry teaching is good for students to arouse study interest and enhance the abilities of autonomic learning, question-analyzing and question-solving as well as consolidate theory knowledge. It is worth generalizing as a new teaching method for biochemistry in medical college.