Objective To investigate the effects of increasing the ejection seat backrest angle on the body pressure distribution of pilots of different body types,and to provide a basis for the design of ejection seats,flight training,and the development of strategies to alleviate muscle fatigue.Methods Male fighter pilots were divided into normal and overweight groups according to their body mass index(BMI),and a total of 40 pilots were tested for the distribution of sitting pressure under the two seat inclination angles of 20°and 33°by using the body pressure distribution measurement system.The effects of different seat inclination angles on sitting comfort were also analyzed.Results The pressure distributions of pilots with different body types were significantly different at different seat inclination angles.Compared with the 20°seat,the 33°seat condition had a larger cushion contact area[F(1,78)=40.281,P<0.001],a smaller average pressure and average pressure gradient[F(1,78)=32.030,P<0.001;F(1,78)=12.594,P<0.001],and significantly reduced average,maximum pressure,and maximal pressure gradients for the backrest[F(1,78)=10.516,P=0.002;F(1,78)=26.803,P<0.001;F(1,78)=4.918,P=0.029,respectively].In addition,overweight individuals with BMI had a notable increase in the cushion contact area[F(1,78)=21.038,P<0.001]and the backrest contact area[F(1,78)=8.301,P=0.005].No significant interaction was observed for angle and BMI.Conclusion An increased seat inclination angle results in a more uniform distribution of pressure across the human body,thereby increasing comfort.Moreover,the disparities in pressure and backrest distribution across disparate body types at varying seat angles provide a vital foundation for the optimized design of seating.

Lung cancer has the highest incidence and mortality among malignant tumors in China.Persistent subsolid nodules(SSNs)are closely associated with early-stage lung adenocarcinoma.Artificial intelligence(AI),as an emerging technology,is capable of performing in-depth analysis of large-scale imaging data through autonomous learning and possesses the ability to predict outcomes from new data,demonstrating great potential and application prospects in the assessment of SSNs.AI can not only effectively assist radiologists in diagnosis and treatment,but also improve work efficiency while reducing misdiagnosis and missed diagnosis rates.This review summarizes the recent applications and research progress of AI in the assessment of SSNs,to provide new insights for the diagnosis and treatment of SSNs.

Objective To investigate the association of digit ratio with single nucleotide polymorphism(SNP)at three loci(rs17576,rs3918249,rs9509)of matrix metallopeptidase 9(MMP-9)gene.Methods A total of 804 Ningxia Han youths(399 males and 405 females)were used as the study subjects.A digital camera was used to take frontal photographs of the hands,and image analysis software was used to mark the anatomical points and measure the lengths of each finger of both hands(2D,3D,4D,5D);Multiplexed PCR was used to detect the three polymorphic sites of the MMP-9 gene,SPSS 25.0 and R Studio software were used for data analysis and plotting.Results The 2D/3D(P＜0.05)and 2D/4D(left,P＜0.01,right,P＜0.05)of both hands,2D/5D(P＜0.01),3D/5D,4D/5D(P＜0.05)of the right hand,and 3D/4D(P＜0.05)of the left hand in female youths of Ningxia Han were significantly higher than those in males,Differences in genotypes and allele frequencies at all 3 loci of the MMP-9 gene were not statistically significant between genders(P＞0.05).Right hand 2D/4D was significantly associated with genotypes at the rs17576 and rs3918249 loci in male youths(P＜0.05).Conclusion MMP-9 gene SNPs(rs17576 and rs3918249)may be associated with the formation of 2D/4D of Ningxia Han male youths.

Hepatocellular carcinoma(HCC)expresses abundant glycolytic enzymes and displays comprehensive glucose metabolism reprogramming.Aldolase A(ALDOA)plays a prominent role in glycolysis;however,little is known about its role in HCC development.In the present study,we aim to explore how ALDOA is involved in HCC proliferation.HCC proliferation was markedly suppressed both in vitro and in vivo following ALDOA knockout,which is consistent with ALDOA overexpression encouraging HCC prolifera-tion.Mechanistically,ALDOA knockout partially limits the glycolytic flux in HCC cells.Meanwhile,ALDOA translocated to nuclei and directly interacted with c-Jun to facilitate its Thr93 phosphorylation by P21-activated protein kinase;ALDOA knockout markedly diminished c-Jun Thr93 phosphorylation and then dampened c-Jun transcription function.A crucial site Y364 mutation in ALDOA disrupted its interaction with c-Jun,and Y364S ALDOA expression failed to rescue cell proliferation in ALDOA deletion cells.In HCC patients,the expression level of ALDOA was correlated with the phosphorylation level of c-Jun(Thr93)and poor prognosis.Remarkably,hepatic ALDOA was significantly upregulated in the promotion and progression stages of diethylnitrosamine-induced HCC models,and the knockdown of Aldoa strikingly decreased HCC development in vivo.Our study demonstrated that ALDOA is a vital driver for HCC development by activating c-Jun-mediated oncogene transcription,opening additional avenues for anti-cancer therapies.

The single photon counting imaging detector based on microchannel plate(MCP)has the characteristics of high sensitivity and low dark count rate,and has been applied to the optical remote sensing detection of weak ultraviolet spectral signals in space.In this work,by using planar array single photon counting imaging detector as the detector,flat-field concave grating as the splitter,and electrodeless discharge lamp(EDL)as the excitation light source,a dispersion detection system suitable for hydride generation-atomic fluorescence spectrometry(HG-AFS)was developed.The wavelength calibration of the system was carried out,and the negative high pressure and EDL stability time of the planar array single photon counting imaging detector were analyzed and optimized.The characteristic emission spectral lines of As and Bi elements excited in the wavelength range of 180-320 nm were analyzed,and the scattering interference in the wavelength range of 257.3-306.7 nm was discussed.The results showed that the AFS dispersion detection system based on the planar array single photon counting imaging detector could detect and analyze the HG-AFS fluorescence signal initially,and the influence of scattering interference on the detection results was effectively avoided.The system had the advantages including simple structure,no refrigeration and temperature control,no moving parts and simultaneous measurement of multi-band.

In this study,an ON/OFF type micro-valve with a sandwich(glass-silicon-glass)structure was designed and fabricated based on the micro-electro-mechanical system(MEMS)technique.The deformable membrane of this micro-valve was prepared on the silicon on insulator(SOI)substrate and sealed using Si-Si bonding and anodic bonding methods.The micro-valve had high-temperature stability and was suitable for integration with other gas chromatography components.The deformable membrane with a thickness of 10 μm was processed on the top silicon of the SOI substrate.The flow control of the micro-valve could be achieved by changing the driving pressure applied to the deformable membrane to deform it.Compared with polymer membranes,the deformable membrane prepared on the top layer silicon of SOI had better temperature stability and could be released using the deep reactive ion etching technique after silicon-silicon bonding,avoiding deformation during the preparation process.In addition,due to the small gap between the membrane and the inlet/outlet holes,the dead volume of the microvalve was very small.The test results indicated that the micro-valve achieved flow control and ON/OFF functions with good repeatability.

A monolithic integrated gas chromatography chip,consisting of a micro gas chromatography column(μGCC)and a micro helium discharge ionization detector(μHDID)was proposed.The chip was fabricated using micro electromechanical system(MEMS)technique,and its sensitivity was improved from two aspects.On one hand,open tubular column was selected as the separation device,and the auxiliary helium channel width of μHDID was modulated based on the microchannel width of the μGCC to match the flow rates of μHDID and μGCC.On the other hand,the electrode structure inside the μHDID collection zone was optimized,a bias electrode group around the collection electrode was constructed,and the ion collection efficiency was improved.After coating HKUST-1 as the stationary phase,the monolithic integrated gas chromatography chip could achieve baseline separation and detection of light hydrocarbon gas mixture(methane,ethane,propane,andn-butane),with a detection limit for propane as low as 25 pg.The chip could carried out test under temperature-programmed conditions,with a resolution of 9.24 for ethane and propane.

A micro gas chromatographic column with mesoporous surface micro column array prepared by anodization method was proposed.A porous support layer with a characteristic pore size of about 30 nm inside the chromatographic column was prepared in situ using anodization method,and a uniform alumina stationary phase was deposited on the mesoporous support layer using atom layer deposition(ALD)technique.The existence of a mesoporous support layer increased surface area of the chromatographic column,thereby increasing the total amount of stationary phase loading and enhancing column capacity,which facilitated chromatographic separation.The test results showed that the porous support layer significantly reduced the longitudinal molecular diffusion and mass transfer resistance of the micro gas chromatographic column,and significantly increased the number of theoretical plates(n-nonane increased by 290.2%).Furthermore,column efficiency of the chromatographic column was less affected by flow rate,which was conducive to rapid separation of heavy hydrocarbon mixtures.

OBJECTIVE: Data on homocysteine (Hcy) status and its determinants are limited among women during pregnancy and postpartum. This cross-sectional study aimed to investigate Hcy levels during pregnancy and postpartum, and to explore the determinants like geographic factor. METHODS: This study was conducted in women at mid-pregnancy, late-pregnancy and postpartum from southern, central and northern China. Approximately 132 women were included in each stratum by the three phases and regions. Plasma Hcy concentrations were assessed using high-performance liquid chromatography (HPLC), with hyperhomocysteinemia defined as > 10.0 µmol/L. Quantile regression was to estimate medians and interquartile ranges ( IQRs), and logistic regression to examine the determinants of hyperhomocysteinemia. RESULTS: For 1,190 women included, the median (IQR) Hcy concentration was 5.66 (4.62, 7.37) μmol/L. The adjusted median in mid-pregnancy, late-pregnancy and postpartum women was 4.75 (4.13, 5.54), 5.72 (4.81, 6.85) and 7.09 (5.65, 8.75) μmol/L, respectively, showing an increasing trend ( P < 0.001). This increasing trend persisted across the three regions. Higher Hcy concentrations were observed in women residing in northern region and those with younger age or lower economic status. A total of 106 (8.9%) women had hyperhomocysteinemia, with a higher prevalence in those residing in northern region (16.0%), or in postpartum women (16.5%). CONCLUSION Hcy levels, varying with geographic region, maternal age and economic status, are increased from mid-pregnancy to late-pregnancy and postpartum, indicating a need to monitor Hcy levels in pregnant and postpartum women to control potential risks related to elevated Hcy levels.
Humans ; Female ; Pregnancy ; Homocysteine/blood* ; China/epidemiology* ; Adult ; Postpartum Period/blood* ; Cross-Sectional Studies ; Hyperhomocysteinemia/blood* ; Young Adult ; Pregnancy Trimester, Third/blood* ; Pregnancy Trimester, Second ; East Asian People

Acute lateral ankle sprain (ALAS) is one of the most common sport injuries, with high incidence, recurrence and disability rates. Currently, exercise rehabilitation-based non-surgical treatment is the primary management approach for ALAS. However, there remain improper practices such as excessive immobilization or uncontrolled activity, which contribute to recurrent sprains and chronic ankle instability, significantly impairing patients′ athletic function and quality of life. To standardize the non-surgical management of ALAS, improve the cure rates, and reduce the recurrence and disability rates, Chinese Sports Rehabilitation Medicine Training Project of Chinese Medical Association, Foot and Ankle Basics and Orthopedics Group, Orthopedic Branch of Chinese Medical Doctor Association, and Sports Medicine Branch of Jiangsu Medical Association organized relevant experts to formulate Expert consensus on non-surgical treatment for acute lateral ankle sprain ( version 2025), following the principles of scientific vigor, practicality, and innovation. Thirteen recommendations were proposed for standardized treatment protocols across different healing phases, aiming to provide references for standard management of ALAS and improve the therapeutic outcomes.