[Establishment and digital simulation of upper airway in patients with adenoid hypertrophy]

Objective: To analyze the flow field characteristics of the upper airway in patients with different adenoid hypertrophy using computational fluid dynamics (CFD). Methods: From November 2020 to November 2021, the cone-beam CT (CBCT) data of 4 patients [2 males and 2 females,age range 5-7 years, mean (6.0±1.2) years] with adenoid hypertrophy who were hospitalized in the Department of Orthodontics and the Department of Otolaryngology at Hebei Eye Hospital were selected. The degree of adenoid hypertrophy in the 4 patients was divided into normal S1 (A/N<0.6), mild hypertrophy S2 (0.6≤A/N<0.7), moderate hypertrophy S3 (0.7≤A/N<0.9) and severe hypertrophy S4 (A/N≥0.9) according to the ratio of adenoid thickness to the width of nasopharyngeal cavity (A/N). The CFD model of the upper airway was established using ANSYS 2019 R1 software, and the internal flow field of the CFD model was numerically simulated. Eight sections were selected as observation and measurement planes for flow field information. Relevant flow field information includes airflow distribution, velocity variation, and pressure variation. Results: In the S1 model, the maximum pressure difference occurred in the 4th and 5th observation planes (ΔP=27.98). The lowest pressures and the maximum flow rates of S2 and S3 were located in the 6th observation plane. The airflow in S1 and S2 models completely passed through the nasal cavity. In the S3 model, the mouth-to-nasal airflow ratio was close to 2∶1. In S4 model, the airflow completely passed through the mouth; in the S1 and S2 models, hard palates were subjected to a downward positive pressure with a pressure difference of 38.34 and 23.31 Pa, respectively. The hard palates in S3 and S4 models were subjected to a downward negative pressure with a pressure difference of -2.95 and -21.81 Pa, respectively. Conclusions: The CFD model can objectively and quantitatively describe the upper airway airflow field information in patients with adenoid hypertrophy. With the increasing degree of adenoid hypertrophy, the nasal ventilation volume gradually decreased, whereas the oral space ventilation volume gradually increased, and the pressure difference between the upper and lower surfaces of the palate gradually decreased until the pressure became negative.

Tunable magnetic and half-metallic properties of the two-dimensional electron gas in LaAlO3/SrTiO3(111) heterostructures

Half-metallic materials have gained a lot of attention because of their unique properties and applications in spintronic devices. Despite the fact that these materials have been studied by several research groups there are very limited studies on their heterostructure (HS) systems. In the current study we have investigated the electronic and magnetic properties of (LaAlO3)6.5/(SrTiO3)2.5(111) HS using density functional theory (DFT) calculations. We demonstrate that the system exhibits a 100% spin-polarized two-dimensional electron gas (2DEG) which is extremely confined to the Ti 3d orbitals of the SrTiO3 layers. In particular, this system can keep its half-metallic properties under different in-plane strains from -3 to 2%. This property proves that this material has relatively stable half-metallic properties. In addition, the conducting and magnetic ground states of the system can also be tailored by changing in-plane strain and interfacial cation intermixing of La and Sr (Sr ⇔ La intermixing). By increasing the in-plane lattice parameters, this system has the ability to evolve from a nonmagnetic to a ferromagnetic metal and then to a half-metal and by further increasing the in-plane lattice parameter it becomes a ferromagnetic insulator. Sr ⇔ La intermixing can destroy the original half-metallic properties and the system exhibits an AFM Mott-type insulator phase. Our results demonstrate that the system has high potential for application in the field of spintronics, and opens the prospect of using LaAlO3/SrTiO3(111) HSs to explore quantum phase transitions.

Combined effect of mutations in ADSL and GARS-AIRS-GART genes on IMP content in chickens

1. The objective of this study was to investigate the effect of ADSL gene, GARS-AIRS-GART gene and their combination genotype on inosine monophosphate content (IMP) in chicken. 2. The chicken breeds used for this study were Recessive White chicken (RW, Jiang-13 strain of white Plymouth Rock) and preserved population of 4 Chinese native chicken breeds, including Silkies, Baier, Tibetan and Xiaoshan. 3. The primers for exon 2 in ADSL gene and 5'UTR region in GARS-AIRS-GART gene were designed and the single nucleotide polymorphisms (SNPs) were detected by PCR-SSCP and DNA sequencing. 4. Two SNPs were detected, C/T substitution at position 3484 in exon 2 of ADSL gene, which was a silent mutation, and C/T point mutation at position -179 in 5'UTR region of GARS-AIRS-GART gene. In ADSL gene, individuals with TT genotype had significantly higher IMP content than CT and CC genotype individuals. No significant difference was observed between CT and CC genotypes. Similar results were obtained for GARS-AIRS-GART gene. The combination of genotypes ADSL and GARS-AIRS-GART genes also had a significant effect on IMP content. Individuals with TTTT genotype had the highest muscle IMP content, while individuals with CCCT genotype had the lowest. 4. We putatively drew the conclusion that the SNPs in these two genes, as well as the combination genotypes, could be used as potential molecular markers for meat quality in chicken.