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

Gelsemium elegans (G. elegans) is an extremely poisonous plant that is widely distributed in southern China and southeastern Asia. G. elegans poisoning events occur frequently in southern China, and are therefore an urgent public health problem requiring multidisciplinary action. However, the toxic components and toxicological mechanisms remain unclear. Here, we describe a systematic investigation on the toxic components of G. elegans, resulting in the isolation and identification of 120 alkaloids. Based on acute toxicity screening, the structure-toxicity relationship of Gelsemium alkaloids was proposed for the first time. Moreover, gelsedine- and humantenine-type alkaloids were detected in the clinical blood sample, and were confirmed to be causative in the poisoning. The most toxic compound, gelsenicine (1), had selective inhibitory effects toward ventral respiratory group (VRG) neurons in the medulla, which is the main brain region controlling respiration in the central nervous system. Gelsenicine (1) strongly inhibited the firing of action potentials in VRG neurons through its ability to stimulate GABA_A receptors, the main receptors involved in inhibitory neurotransmission. Application of GABA_A receptor antagonists successively reversed action potential firing in gelsenicine (1)-treated VRG neurons. Importantly, the GABA_A receptor antagonists securinine and flumazenil significantly increased the survival of poisoned animals. Our findings provide insight into the components and mechanisms of G. elegans toxicity, and should assist the development of effective emergency treatments for G. elegans poisoning.

Objective:To investigate the effect and mechanism of injectable photopolymerizable porous gelatin methacrylate anhydride (Porous GelMA)/methacrylated silk fibroin (SilMA) composite hydrogel (PSE) loaded with human umbilical cord mesenchymal stem cell-derived exosomes (hUCMSC-Exos) in promoting knee joint cartilage regeneration.Methods:The porous GelMA solution (60 g/L) was mixed with SilMA solution (200 g/L) at a volume ratio of 6∶1 . The mixture was ultraviolet-irradiated for 30 seconds to form a cured Porous GelMA/SilMA hydrogel (P/S6). The hUCMSC-Exos was isolated via differential centrifugation coupled with ultrafiltration and then was incorporated into the Porous GelMA/SilMA composite solution at 200 μg/ml, followed by ultraviolet irradiation for 30 seconds to generate Exos-loaded PSE. Primary rat chondrocytes (P1) were divided into control group, P/S6 group, and PSE group to characterize the porosity, compressive strength, and sustained exosome release kinetics of PSE hydrogel. Chondrocytes were allocated to control group, interleukin-1β (IL-1β) group, P/S6 group, and PSE group, among which the last three groups were preconditioned with 10 ng/ml IL-1β for 24 hours, and then cultured in complete medium, P/S6 extract and PSE extract for 3 days, respectively, to establish in vitro cartilage defect models, while the control group remained untreated. Western blot and qRT-PCR analysis were conducted to quantify the expression levels of antibody to aggrecan core protein (ACAN), sex-determining region Y-box transcription factor 9 (SOX9), matrix metalloproteinase-13 (MMP13) and collagen type II (COL II). Murine monocyte-macrophage leukemia cells (RAW264.7) were divided into control group, P/S6 group, and PSE group, which were then cultured in complete medium, PSE extract, and PSE extract medium for 3 days, respectively. qRT-PCR was employed to detect the expression levels of recombinant arginase-1 protein (ARG1), mannose receptor (CD206), and inducible nitric oxide synthase (iNOS). Transcriptomic sequencing was used to identify differentially expressed genes during PSE-mediated chondrocyte regeneration, followed by functional enrichment analysis of key signaling pathways. Twenty-four SD rats were selected to establish cartilage defect models and assigned to injury control group, P/S6 group, and PSE group according to the random number table (8 rats per group). The right knee joints of the rats were surgically exposed, and cylindrical osteochondral defects (a diameter of 2.0 mm× a depth of 1.0 mm) were surgically created in the center of the femoral trochlear groove using a drill bit. The injury control group received phosphate-buffered saline, while the P/S6 group and PSE group were injected with corresponding hydrogels followed by photo-crosslinking. Incisions then were closed in layers. At 6 and 10 weeks after injury, specimens were harvested for HE staining and safranin O-fast green staining to evaluate cartilage regeneration and immunohistochemistry staining to quantify the positive area fractions for COL II, MMP13, ARG1, and CD206 in the defect areas. Results:PSE hydrogel exhibited compressive strength matching native cartilage (0.41 MPa), high porosity (85%), and sustained exosome release capacity (cumulative release rate of approximately 85% over 14 days). In chondrocyte repair experiments, compared to the IL-1β group, the PSE group demonstrated significantly upregulated expression of anabolic markers of cartilage (COL II expression increased by 2.1-fold, ACAN by 1.8-fold, and SOX9 by 1.5-fold) ( P<0.01) as well as significantly suppressed expression of catabolic markers (MMP13 expression decreased by 52%) ( P<0.01). In macrophage polarization assays, the PSE group exhibited ARG1 expression increased by 68% when compared to the control group ( P<0.01), thus promoting M2 polarization of macrophages. Transcriptomic analysis revealed that PSE enhanced extracellular matrix (ECM) synthesis by activating the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathway and ECM-receptor interaction pathway, as well as by suppressing inflammation-related gene expression. Histological evaluation in animal experiments revealed regeneration of hyaline cartilage with smooth, continuous surfaces in the defect areas in the PSE group. At 10 weeks after surgery, the neocartilage-positive area in the PSE group was (9.94±0.26)%, significantly larger than (1.67±0.11)% in the injury control group ( P<0.01). Besides, the CD206? M2 macrophage-positive area reached (14.44±0.23)% in the PSE group, significantly larger than (3.41±0.36)% in the injury control group ( P<0.01). Conclusions:The PSE hydrogel successfully engineered in the study can significantly promote regenerative repair of knee cartilage defects through a dual mechanism of enhanced ECM anabolism and remodeled inflammatory microenvironment. The core mechanisms involve specific activation of the PI3K/Akt pathway (boosting chondrocyte proliferation and survival) and ECM-receptor interaction pathway (driving ECM synthesis and assembly) by exosome-loaded PSE, while effectively polarizing macrophages toward an anti-inflammatory M2 phenotype so as to coordinately regulate cartilage ECM metabolism and suppress inflammatory responses.

Objective:To investigate the clinical phenotypes and genetic variant characteristics in children with epilepsy.Methods:A total of 91 children with epilepsy admitted to the Women′s and Children′s Hospital Affiliated to Ningbo University from July 2021 to October 2022 were selected as the study subjects. Peripheral blood samples were collected from the children for whole exome sequencing. Candidate genetic variants were validated by Sanger sequencing and copy number variation sequencing (CNV-seq). The clinical phenotypes and treatment outcomes of the children with epilepsy were followed up, and an analysis of the relationship between genotype and phenotype was conducted. This study was approved by the Women′s and Children′s Hospital Affiliated to Ningbo University (Ethics No.: EC2020-048).Results:Among the 91 children with epilepsy, 21 cases (23.08%, 21/91) were found to carry pathogenic or likely pathogenic variants. Of these, 18 cases had involved single base variant or insertional deletion, while 3 cases involved copy number variations. The gene with the highest detection rate was PRRT2 (38.10%, 8/21). Among the children with genetic variants, 47.62% (10/21) had onset during infancy, with 8 diagnosed with Benign familial infantile epilepsy (BFIE), 8 with Developmental epileptic encephalopathy (DEE), and 3 with Epileptic encephalopathy (EE). One case of Dravet syndrome (DS) and one case of Infantile spasms (IS) were also noted. The clinical manifestations of children were diverse and primarily included generalized tonic-clonic seizures and focal seizures. Among them, 52.38% (11/21) had exhibited cluster seizures, 23.81% (5/21) showed fever sensitivity, and 14.29% (3/21) experienced status epilepticus. After pharmacological treatment, 42.86% (9/21) of children had achieved complete seizure control, while 61.90% (13/21) had intellectual disability and 19.05% (4/21) had co-morbid autism spectrum disorder. Conclusion:Pathogenic or likely pathogenic variants were identified in 23.08% of the pediatric epilepsy cases, with the PRRT2 gene being the most frequently involved. Among children carrying genetic variants, 47.62% had seizure onset during infancy. Genetic factors are an important cause of epilepsy, and early genetic testing may facilitate precise diagnosis, treatment, and prognostic evaluation.

Objective: To investigate the awareness of knowledge about hepatitis C prevention and control among outpatients in Ningbo City, Zhejiang Province, and its influencing factors, so as to provide the evidence for strengthening health education on hepatitis C prevention and control. Methods: Based on sentinel surveillance of hepatitis C, the outpatients aged 15 to 65 years at seven hospitals in Yinzhou District, Cixi City and Xiangshan County of Ningbo City were selected using the convenient sampling method from April to June during 2020 and 2022. Demographic information, knowledge and behaviors related to hepatitis C prevention and control were collected through questionnaire surveys. The influencing factors for knowledge about hepatitis C prevention and control were analyzed using a multivariable logistic regression model. Results: A total of 2 792 participants were surveyed, including 1 157 males (41.44%) and 1 635 females (58.56%). The awareness rate of knowledge about hepatitis C prevention and control was 56.23%, and was lower in knowledge about hepatitis C vaccine and treatment. The awareness rates of knowledge about hepatitis C prevention and control among outpatients from 2020 to 2022 were 47.11%, 53.22% and 70.65%, respectively, showing an upward trend (P<0.05). Multivariable logistic regression analysis showed that participants aged 25 to <50 years (OR=1.358, 95%CI: 1.073-1.719), with an educational level of high school or junior college (OR=1.431, 95%CI: 1.134-1.806) or above junior college (OR=3.728, 95%CI: 2.958-4.699), with household monthly income per capita of 3 000 to <5 000 yuan (OR=1.828, 95%CI: 1.344-2.486) or ≥5 000 yuan (OR=1.858, 95%CI: 1.366-2.526), without a history of invasive treatments such as pedicure in public places (OR=1.287, 95%CI: 1.024-1.618), without a history of contact with family members' blood-contaminated items (OR=2.050, 95%CI: 1.552-2.707), and always using condoms during sexual contacts (OR=1.740, 95%CI: 1.273-2.378) had higher awareness of knowledge about hepatitis C prevention and control. Conclusions The awareness of knowledge about hepatitis C vaccine and treatment among outpatients in Ningbo City needs to be improved. Age, educational level, household monthly income per capita, history of invasive treatments such as pedicure in public places, history of contact with family members' blood-contaminated items and frequency of condom use during sexual contacts are associated with outpatients' awareness of knowledge about hepatitis C prevention and control.

AIM: To investigate the changes of microRNA-34a(miR-34a)and microRNA-29b(miR-29b)levels in lens epithelial cells of age-related cataracts(ARC)patients and their clinical significance.METHODS: A total of 65 ARC patients(study group)and 53 cases of clear lens anterior capsulorhexis(control group)who visited our hospital from February 2023 to February 2024 were gathered. Pearson was applied to test the correlation between miR-34a and miR-29b. Multifactor Logistic regression was applied to determine the factors affecting the occurrence of ARC.RESULTS: Compared with the control group, the expression levels of miR-34a and miR-29b in lens epithelial cells of the research group showed a significant decrease trend(all P<0.05). There was a positive correlation between miR-34a and miR-29b in the lens epithelial cells of ARC patients(r=0.472, P<0.05). MiR-34a and miR-29b were influence factors for ARC(all P<0.05).CONCLUSION: The levels of miR-34a and miR-29b in lens epithelial cells of ARC patients are significantly reduced, which is associated with the occurrence of ARC.

Rapid and ultrasensitive detection of pathogen-associated biomarkers is vital for the early diagnosis and therapy of bacterial infections.Herein,we developed a close-packed and ordered Au@AgPt array coupled with a cascade triggering strategy for surface-enhanced Raman scattering(SERS)and colorimetric identification of the Staphylococcus aureus biomarker micrococcal nuclease(MNase)in serum samples.The trimetallic Au@AgPt nanozymes can catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)molecules to SERS-enhanced oxidized TMB(oxTMB),accompanied by the color change from colorless to blue.In the presence of S.aureus,the secreted MNase preferentially cut the nucleobase AT-rich regions of DNA sequences on magnetic beads(MBs)to release alkaline phosphatase(ALP),which subsequently mediated the oxTMB reduction for inducing the colorimetric/SERS signal fade away.Using this"on-to-off"triggering strategy,the target S.aureus can be recorded in a wide linear range with a limit of detection of 38 CFU/mL in the colorimetric mode and 6 CFU/mL in the SERS mode.Meanwhile,the MNase-mediated strategy characterized by high specificity and sensitivity successfully discriminated between patients with sepsis(n=7)and healthy participants(n=3),as well as monitored the prog-nostic progression of the disease(n=2).Overall,benefiting from highly active and dense"hot spot"substrate,MNase-mediated cascade response strategy,and colorimetric/SERS dual-signal output,this methodology will offer a promising avenue for the early diagnosis of S.aureus infection.

OBJECTIVE: To investigate the clinical phenotypes and genetic variant characteristics in children with epilepsy. METHODS: A total of 91 children with epilepsy admitted to the Women's and Children's Hospital Affiliated to Ningbo University from July 2021 to October 2022 were selected as the study subjects. Peripheral blood samples were collected from the children for whole exome sequencing. Candidate genetic variants were validated by Sanger sequencing and copy number variation sequencing (CNV-seq). The clinical phenotypes and treatment outcomes of the children with epilepsy were followed up, and an analysis of the relationship between genotype and phenotype was conducted. This study was approved by the Women's and Children's Hospital Affiliated to Ningbo University (Ethics No.: EC2020-048). RESULTS: Among the 91 children with epilepsy, 21 cases (23.08%, 21/91) were found to carry pathogenic or likely pathogenic variants. Of these, 18 cases had involved single base variant or insertional deletion, while 3 cases involved copy number variations. The gene with the highest detection rate was PRRT2 (38.10%, 8/21). Among the children with genetic variants, 47.62% (10/21) had onset during infancy, with 8 diagnosed with Benign familial infantile epilepsy (BFIE), 8 with Developmental epileptic encephalopathy (DEE), and 3 with Epileptic encephalopathy (EE). One case of Dravet syndrome (DS) and one case of Infantile spasms (IS) were also noted. The clinical manifestations of children were diverse and primarily included generalized tonic-clonic seizures and focal seizures. Among them, 52.38% (11/21) had exhibited cluster seizures, 23.81% (5/21) showed fever sensitivity, and 14.29% (3/21) experienced status epilepticus. After pharmacological treatment, 42.86% (9/21) of children had achieved complete seizure control, while 61.90% (13/21) had intellectual disability and 19.05% (4/21) had co-morbid autism spectrum disorder. CONCLUSION Pathogenic or likely pathogenic variants were identified in 23.08% of the pediatric epilepsy cases, with the PRRT2 gene being the most frequently involved. Among children carrying genetic variants, 47.62% had seizure onset during infancy. Genetic factors are an important cause of epilepsy, and early genetic testing may facilitate precise diagnosis, treatment, and prognostic evaluation.
Humans ; Female ; Male ; Epilepsy/genetics* ; Child, Preschool ; Child ; Phenotype ; Genotype ; DNA Copy Number Variations/genetics* ; Infant ; Membrane Proteins/genetics* ; Nerve Tissue Proteins/genetics* ; Adolescent ; Exome Sequencing

Objective To explore the value of ultrasound artificial intelligence(AI)in assisting naval grassroots doctors for the diagnosis of thyroid nodule in naval.Methods A total of 177 patients with thyroid nodules(200 thyroid nodules)who visited The First Affiliated Hospital of Naval Medical University from November 2020 to November 2023 were selected as research objects.The thyroid nodules were diagnosed by naval grassroots doctors,naval grassroots doctors assisted by AI,and senior doctors,respectively.Results The pathological results showed that there were 110 malignant nodules and 90 benign nodules.The diagnostic accuracy rate of AI-assisted group(85.0%)was similar to that of senior doctor group(87.0%),which were higher than that of naval grassroots doctor group(71.5%).Pathological results were taken as the gold standard,Kappa consistency test was carried out,and the area under the receiver operating characteristic(ROC)curve(AUC)was compared among groups.The diagnostic results of naval grassroots doctor group had a moderate consistency with pathological results(Kappa value was 0.424,P<0.001).The diagnostic results of AI group and senior doctor group had strong consistencies with pathological results(Kappa values were 0.693 and 0.735,respectively,both P<0.001).There was no significant difference in the AUC between AI group and senior doctor group(0.842 vs.0.864,P>0.05).However,there was a significant difference in the AUC between naval grassroots doctor group and AI group(0.712 vs.0.842,P<0.001).Conclusion AI can assist naval grassroots doctors in improving the diagnostic level of thyroid nodules.It has certain application prospects in naval forces.

Objective To investigate the interaction between a novel antimicrobial compound,HL-J6,and penicillin-binding protein 1(PBP1)of Staphylococcus aureus.Methods With MRSA252 genomic DNA as the template and PBP1F and PBP1R as primers,the expression plasmid pET30a-pbp1-39-608 was constructed by amplifying the target gene fragment followed by cloning into the Nde I/Xho I restriction sites of the pET30a vector.Then the obtained plasmids were transformed into Escherichia coli for the expression of PBP1-39-608 protein,and the product was purified by affinity chromatography.The inhibitory effect of HL-J6 on the transpeptidase activity of PBP1-39-608 was measured using peptidoglycan side chain backbone peptide,with thiol ester analog S2d as the substrate.The affinity between HL-J6 and PBP1-39-608 was detected using microscale thermophoresis(MST),and the binding interaction was confirmed by cellular thermal shift assay(CETSA).Molecular docking and dynamics simulation were performed using AutoDock Vina and Desmond software,respectively,to elucidate the binding mode of HL-J6 with the PBP1-39-608 protein and the key amino acid residues involved.Results The recombinant plasmid pET30a-pbp1-39-608 was successfully constructed,and PBP1-39-608 protein was produced after induction and purified,yielding a protein with an approximate molecular mass of 65×103.HL-J6 inhibited the transpeptidase activity of PBP1-39-608 in a time-dependent manner(P<0.001).The dissociation constant Kd of the binding between HL-J6 and PBP1-39-608 was 64.92 μmol/L.Molecular docking results showed that HL-J6 bound to the active pocket of PBP1-39-608 by interacting with key residues such as ILE-348,ASN-370,THR-516 and PHE-423,with a binding score of-8.38 kcal/mol(<-5.00 kcal/mol).Dynamics simulation results indicated that the complex became stable after 50 ns.Conclusion HL-J6 effectively inhibits the transpeptidase activity of Staphylococcus aureus PBP1,and shows stable interaction with the protein.