Metabolic obesity phenotypes and all-cause mortality among the Chinese oldest-old population: a prospective cohort study.

BACKGROUND: The obesity paradox has been reported among older adults. However, whether the favorable effect of obesity is dependent on metabolic status remains largely unknown. We aimed to explore the association of metabolic obesity phenotypes and their changes with all-cause mortality among the Chinese oldest-old population. METHODS: This prospective cohort study included 1207 Chinese oldest old (mean age: 91.8 years). Metabolic obesity phenotypes were determined by central obesity and metabolic status, and participants were classified into metabolically healthy obesity (MHO), metabolically unhealthy obesity (MUO), metabolically healthy non-obesity (MHN), and metabolically unhealthy non-obesity (MUN). The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated by Cox regression models. RESULTS: During 5.3 years of follow-up, 640 deaths were documented. Compared with non-obesity, obesity was associated with a decreased mortality risk among participants with metabolically healthy (HR, 0.75; 95% CI, 0.63-0.91) while this association was insignificant among metabolically unhealthy. Compared to MHO, MHN (HR, 1.27; 95% CI, 1.06-1.53) and MUN (HR, 1.49; 95% CI, 1.10-2.02) were significantly associated with an increased mortality risk. Compared to those with stable MHO, those transited from MHO to MUO demonstrated a higher mortality risk (HR, 1.81; 95% CI, 1.06-3.11). CONCLUSIONS: MHO predicts better survival among the Chinese oldest-old population. These findings suggest that ensuring optimal management of metabolic health is beneficial and taking caution in weight loss based on the individual body weight for the metabolically healthy oldest-old adults.

Association between two novel anthropometric measures and type 2 diabetes in a Chinese population.

AIMS: To investigate the associations of conicity index (C-index) and relative fat mass (RFM) with incident type 2 diabetes mellitus (T2DM) among adults in China. MATERIALS AND METHODS: A total of 10 813 participants aged over 18 years in Shenzhen Longhua district were enrolled in a follow-up study conducted from 2018 to 2022. The participants were categorized based on quartiles (Q) of C-index and RFM. The Cox proportional hazards model was performed to examine the relationships between C-index, RFM and the risk of T2DM. RESULTS: After adjusting for potential confounding factors, including age, sex, occupation, marital status, education level, smoking status, alcohol consumption, physical exercise, hypertension status, fasting blood glucose (FBG) and total cholesterol (TC), both C-index and RFM showed positive and independent associations with risk of T2DM. The multivariable-adjusted hazard ratios (95% confidence intervals) for T2DM risk in participants in C-index Q3 and Q4 compared with those in C-index Q1 were 1.50 (1.12, 2.02) and 1.73 (1.29, 2.30), and 1.94 (1.44, 2.63), 3.18 (1.79, 5.64), 4.91 (2.68, 9.00) for participants in RFM Q2, Q3 and Q4 compared with RFM Q1. These differences were statistically significant (all p < 0.05). CONCLUSION: C-index and RFM are strongly associated with new-onset T2DM and could be used to identify the risk of diabetes in large-scale epidemiological studies.

Nonlinear error analysis of fast optical delay lines.

Optical delay lines have wide applications in terahertz time-domain spectroscopy and optical coherence tomography. In this study, a fast-rotating optical delay line (FRODL) with 24 turntable reflection surfaces was designed. By analyzing the working principle of the FRODL, a mathematical model was established for the nonlinear parameter error of the FRODL delay time. By constructing the polarization Michelson interference system and testing the FRODL structure, the error of actual assembly parameters of the FRODL was approximately 0.015 mm, the actual delay time of the FRODL was greater than 43.5 ps, and the linearity was 99.785%.

Association of screening status, polygenic risk score and environmental risk factors with colorectal cancer incidence and mortality risks.

Whether screening can attenuate the influence of genetic risk and environmental risk factors for colorectal cancer (CRC) mortality risk remains unknown. Our study is to investigate the association of the screening history, genetic risk and environmental risk factors with CRC incidence and mortality risks using UK Biobank data. Screening history was associated with lower CRC incidence (hazard ratio [HR]: 0.63, 95% confidence interval [CI]: 0.58-0.69) and mortality risk (HR: 0.56, 95% CI: 0.49-0.63). Compared to the HRs of participants with a low genetic risk, low environmental risk and no screening history, the HRs of participants with a high genetic risk, high environmental risk and no screening history were 3.42 (95% CI: 2.76-4.24) for CRC incidence and 3.36 (95% CI: 2.48-4.56) for CRC mortality. In contrast, the HRs of participants with a high genetic risk and no screening history, but a low environmental risk, were 1.92 (95% CI: 1.55-2.36) for CRC incidence and 1.88 (95% CI: 1.39-2.53) for CRC mortality. Furthermore, the HRs of participants with a high genetic risk and a low environmental risk, but a screening history were 1.62 (95% CI: 1.15-2.28) for CRC incidence and 1.77 (95% CI: 1.08-2.89) for CRC mortality. Participants benefited more substantially from screenings for CRC mortality than for CRC incidence risk. A higher environmental risk was associated with higher risk of CRC incidence and mortality within each category of genetic risk. These findings emphasize the importance of CRC screening and identifying environmental factors to reduce CRC incidence and mortality risks.

Serum 25-hydroxyvitamin D concentrations and colorectal cancer incidence in adults with type 2 diabetes.

BACKGROUND: To examine the association of serum 25-hydroxyvitamin D (25[OH]D) with colorectal cancer (CRC) risk in adults with type 2 diabetes (T2D). METHODS: Using UK Biobank data, this study included 18,453 adults with T2D. Serum 25(OH)D concentrations were determined by the chemiluminescent immunoassay method. A Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for CRC outcomes. RESULTS: During a median follow-up of 8.8 years, there were 284 incident CRC cases. Compared with adults with serum 25(OH)D concentrations <25.0 nmol/L, the adjusted HRs (95% CIs) for lower to higher serum 25(OH)D concentrations (25.0 to <50.0, 50.0 to <75.0, and ≥75.0 nmol/L) were 0.61 (0.46-0.82), 0.50 (0.34-0.74), and 0.53 (0.30-0.94), respectively (Ptrend = 0.001). The risk of CRC decreased by 19.0% for per 1-SD increment in serum 25(OH)D concentrations. A nonlinear association of serum 25(OH)D concentrations with CRC risk was observed using a restricted cubic spline analysis (P nonlinearity = 0.002). CONCLUSIONS: Higher serum 25(OH)D concentrations were significantly and nonlinearly associated with a lower risk of CRC. These findings highlight the potential benefits of maintaining adequate vitamin D levels in CRC prevention among adults with T2D.

Changes in vaginal microbiome after focused ultrasound treatment of high-risk human papillomavirus infection-related low-grade cervical lesions.

BACKGROUND: In this study, the changes of vaginal microbiome after focused ultrasound (FU) treatment were evaluated to explore the possible mechanism of FU in the treatment of high-risk human papillomavirus (HR-HPV) infection. METHODS: This study was nested in the FU arm of a prospective cohort study. A total of 37 patients diagnosed with HR-HPV infection-related cervical low-grade squamous intraepithelial lesion (LSIL) who met the inclusion criteria were enrolled in this study from October 2020 to November 2021, and these patients were treated with FU. We used 16S ribosomal RNA (16S rRNA) gene amplicon sequencing to profile the vaginal microbiota composition of patients before and 3 months after FU treatment. RESULTS: After FU treatment, HR-HPV was cleared in 24 patients, with a clearance rate of 75.0% (24/32). Lactobacillus iners was the predominant species among all samples. No significant difference was found in alpha-diversity index before and 3 months after FU treatment (P > 0.05), but the rarefaction curves showed that the vaginal microbial diversity before FU treatment was higher than that after FU treatment. Linear discriminant analysis (LDA) effect size (LEfSe) showed that Bifidobacterium contributed the most to the difference between the two groups at the genus level, and the abundance after FU treatment was significantly higher than that before treatment (P = 0.000). CONCLUSIONS: The decrease of vaginal microbial diversity may be related to the clearance of HR-HPV infection, and FU treatment contributed to the decrease of vaginal microbial diversity. Increased Bifidobacterium abundance in the vaginal microbiome may be associated with clearance of HR-HPV infection, and FU treatment may contribute to the increase in Bifidobacterium abundance. TRIAL REGISTRATION NUMBER:  This study was registered in the Chinese Clinical Trial Registry on 23/11/2020 (ChiCTR2000040162).

Long-term air pollution exposure, habitual physical activity, and incident chronic kidney disease.

Both air pollution and physical inactivity contribute to the increased risk of incident chronic kidney disease (CKD). However, the detrimental effects of air pollution exposure could be augmented by an elevated intake of air pollutants during exercise. In the present study, we analyzed 367,978 participants who were CKD-free at baseline (2006-2010) based on the UK Biobank. Air pollutants included fine particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), and nitrogen oxides (NOX). Physical activity (PA) was obtained by the self-reported questionnaire. Using Cox proportional hazards models, hazard ratios (HRs) for incident CKD related to air pollution, PA, and incident CKD were evaluated. During a median of 12.4 years of follow-up, 14,191 incident CKD events were documented. High PM2.5, PM10, NO2, and NOX increased CKD risks by 11 %, 15 %, 14 %, and 12 %, respectively, while moderate and high PA reduced CKD risks by 18 % and 22 %, respectively. Participants with high PA and low air pollution exposure had 29 %, 31 %, 30 %, and 30 % risks of incident CKD than those with low PA and high air pollution exposure for the four air pollutants, with multivariable-adjusted HRs of 0.71 (95 % confidence intervals [CI]: 0.65-0.76) for PM2.5, 0.69 (95 % CI: 0.64-0.75) for PM10, 0.70 (95 % CI: 0.64-0.75) for NO2, and 0.70 (95 % CI: 0.64-0.75) for NOX. No clear interactions were observed between each air pollutant exposure and PA (all P for interaction > 0.05). The findings that reducing air pollution exposure and increasing PA were both independently correlated with a diminished risk of incident CKD suggest that PA could be targeted to prevent CKD generally regardless of air pollution levels. Further research is needed in areas polluted moderately and severely to examine our findings.

Identification and fine mapping of a major QTL (qRtsc8-1) conferring resistance to maize tar spot complex and validation of production markers in breeding lines.

KEY MESSAGE: A major QTL of qRtsc8-1 conferring TSC resistance was identified and fine mapped to a 721 kb region on chromosome 8 at 81 Mb, and production markers were validated in breeding lines. Tar spot complex (TSC) is a major foliar disease of maize in many Central and Latin American countries and leads to severe yield loss. To dissect the genetic architecture of TSC resistance, a genome-wide association study (GWAS) panel and a bi-parental doubled haploid population were used for GWAS and selective genotyping analysis, respectively. A total of 115 SNPs in bin 8.03 were detected by GWAS and three QTL in bins 6.05, 6.07, and 8.03 were detected by selective genotyping. The major QTL qRtsc8-1 located in bin 8.03 was detected by both analyses, and it explained 14.97% of the phenotypic variance. To fine map qRtsc8-1, the recombinant-derived progeny test was implemented. Recombinations in each generation were backcrossed, and the backcross progenies were genotyped with Kompetitive Allele Specific PCR (KASP) markers and phenotyped for TSC resistance individually. The significant tests for comparing the TSC resistance between the two classes of progenies with and without resistant alleles were used for fine mapping. In BC5 generation, qRtsc8-1 was fine mapped in an interval of ~ 721 kb flanked by markers of KASP81160138 and KASP81881276. In this interval, the candidate genes GRMZM2G063511 and GRMZM2G073884 were identified, which encode an integral membrane protein-like and a leucine-rich repeat receptor-like protein kinase, respectively. Both genes are involved in maize disease resistance responses. Two production markers KASP81160138 and KASP81160155 were verified in 471 breeding lines. This study provides valuable information for cloning the resistance gene, and it will also facilitate the routine implementation of marker-assisted selection in the breeding pipeline for improving TSC resistance.

Focused ultrasound for high-risk human papillomavirus infection-related low-grade cervical lesions: a prospective cohort study.

OBJECTIVES: To assess the efficacy and safety of focused ultrasound (FU) for high-risk human papillomavirus (HR-HPV) infection-related cervical low-grade squamous intraepithelial lesions (LSIL). METHODS: Of 185 patients who met the inclusion criteria for this prospective study from October 2020 to November 2021, 95 received FU and 90 were followed up only. At the six-month follow-up, the HR-HPV clearance and LSIL regression rates of the groups were compared and factors affecting HR-HPV clearance were analyzed. The safety and side effects of FU were evaluated. RESULTS: No significant difference was found in the baseline clinical data between the two groups (p > 0.05). At the six-month follow-up, the HR-HPV clearance rates were 75.6% in the FU group and 25.6% in the observation group (p = 0.000). The LSIL regression rates were 89.5% in the FU group and 56.4% in the observation group (p = 0.000). Multivariate logistic regression analysis showed that the HR-HPV clearance rate in the FU group was 9.03 times higher than that in the observation group (95% confidence interval [CI], 3.75-21.73, p = 0.000), and the clearance rate of single-type HR-HPV infections was 5.28 times higher than that of multi-type infections (95% CI, 1.83-15.23, p = 0.002). The mean intraoperative bleeding was 1.8 ± 0.6 (1-3) mL; the mean intraoperative pain score was 2.6 ± 1.0 (1-6). CONCLUSIONS: For patients with HR-HPV infection-related histological LSIL, FU can eliminate HR-HPV infection and cause lesions to regress in a short time, with few adverse effects and good tolerance.

Terahertz Multiple Echoes Correction and Non-Destructive Testing Based on Improved Wavelet Multi-Scale Analysis.

During terahertz (THz) non-destructive testing (NDT), multiple echoes from the sample interface reflection signals are mixed with the detection signals, resulting in signal distortion and affecting the accuracy of the THz NDT results. Combined with the frequency property of multiple echoes, an improved wavelet multi-scale analysis is put forth in this paper to correct multiple echoes, allowing the maximum retention of detailed signal information in contrast with the existing echo correction methods. The results showed that the improved wavelet multi-scale analysis enhanced the continuity and smoothness of the image at least twice in testing adhesive layer thickness, prevented missing judgments and misjudgments in identifying characteristic defects, and ensured accurate detection results. Hence, it is of great significance for evaluating the THz NDT results.

THz imaging technique for nondestructive analysis of debonding defects in ceramic matrix composites based on multiple echoes and feature fusion.

We propose a THz nondestructive analysis method based on multiple echoes and feature fusion. Conventionally, it is difficult to identify the debonding defects of the glue layer (II) due to the thin adhesive layer. To this end, a THz propagation model is established, and a quantitative method for determining the thickness of debonding defects based on multiple echoes is presented. The measurement error for preset defect thickness of 500 µm was 4%. Further, for determining the area of debonding defects, a feature fusion imaging algorithm is proposed to realize the lateral recognition of defects and quantitative analysis is used to improve the recognition ability of defects.

QTL mapping of spontaneous haploid genome doubling using genotyping-by-sequencing in maize (Zea mays L.).

KEY MESSAGE: A major QTL for SHGD was identified on chromosome 5 with stable expression across environments. The introgression this QTL can overcome the need of colchicine in DH lines development. Genome doubling of haploids is one of the major constraints of large-scale doubled haploid (DH) technology. Improving spontaneous haploid genome doubling (SHGD) is an alternative to overcome this limitation. In this study, we aimed to construct a high-density linkage map based on genotyping by sequencing of single nucleotide polymorphism, to detect QTL and QTL by environment (Q by E) interactions affecting SHGD and to identify the best trait for mapping and selection of haploid male fertility (HMF). To this end, a biparental population of 220 F2:3 families was developed from a cross between A427 (high HMF) and CR1Ht (moderate HMF) to be used as donor. A high-density linkage map was constructed containing 4171 SNP markers distributed over 10 chromosomes with an average distance between adjacent markers of 0.51 cM. QTL mapping for haploid fertile anther emergence, pollen production, tassel size, and HMF, identified 27 QTL across three environments, and Q by E interactions were significant. A major QTL was identified on chromosome 5. This QTL explained over 45% of the observed variance for all traits across all environments. The introgression of this major QTL, using marker-assisted backcrossing, has great potential to overcome the need of using colchicine in DH line development.

Identifying factors associated with depression among men living with HIV/AIDS and undergoing antiretroviral therapy: a cross-sectional study in Heilongjiang, China.

BACKGROUND: Depression is common among people living with HIV/AIDS; however, studies focusing on the depression of men living with HIV/AIDS are limited. Therefore, we examined the prevalence of depression and its associated factors among men living with HIV/AIDS in China. METHODS: A cross-sectional questionnaire survey was conducted in Harbin, China between March and August in 2013. Two-hundred twenty participants completed the Burns Depression Checklist, the Berger HIV Stigma, and the SPIEGEL questionnaire. We also investigated demographics, family support, hostility, and the antiretroviral therapy side effects of men living with HIV/AIDS. RESULTS: More than 40% of respondents had depressive symptoms and worry about the health was the major symptom of depression (40.9%). The logistic regression model indicated that bad sleep quality (OR = 3.452), hostility (OR = 1.120), perceived discrimination (OR = 1.110), and antiretroviral therapy side effects (OR = 1.083) were positively associated with depression. Family support (OR = 0.860) was negatively associated with depression for men living with HIV/AIDS. Demographic variables, HIV infection route, disease duration, and CD4+ cell count had no significant associations with depression. CONCLUSION: Although China's work of national HIV prevention and treatment has made much progress during the past several years, the prevalence of depression among men living with patients with HIV/AIDS is still prominent. The strongest factor associated with depression among men living with HIV/AIDS was sleep quality. Future studies should explore the effects of interventions for depression among PLWHA.

Novel technologies in doubled haploid line development.

haploid inducer line can be transferred (DH) technology can not only shorten the breeding process but also increase genetic gain. Haploid induction and subsequent genome doubling are the two main steps required for DH technology. Haploids have been generated through the culture of immature male and female gametophytes, and through inter- and intraspecific via chromosome elimination. Here, we focus on haploidization via chromosome elimination, especially the recent advances in centromere-mediated haploidization. Once haploids have been induced, genome doubling is needed to produce DH lines. This study has proposed a new strategy to improve haploid genome doubling by combing haploids and minichromosome technology. With the progress in haploid induction and genome doubling methods, DH technology can facilitate reverse breeding, cytoplasmic male sterile (CMS) line production, gene stacking and a variety of other genetic analysis.

QTL mapping for haploid male fertility by a segregation distortion method and fine mapping of a key QTL qhmf4 in maize.

KEY MESSAGE: Four QTL related to haploid male fertility were detected by a segregation distortion method and the key QTL qhmf4 was fine mapped to an interval of ~800 kb. Doubled haploid (DH) technology enables rapid development of homozygous lines in maize breeding programs. However, haploid genome doubling is a bottleneck for the commercialization of DH technology and is limited by haploid male fertility (HMF). This is the first study reporting the quantitative trait locus (QTL) analysis of HMF in maize. Four QTL, qhmf1, qhmf2, qhmf3, and qhmf4, controlling HMF have been identified by segregation distortion (SD) loci detection in the selected haploid population derived from 'Yu87-1/Zheng58'. Three loci, qhmf1, qhmf2, and qhmf4, were also detected in the selected haploid population derived from '4F1/Zheng58'. The QTL qhmf4 showed the strongest SD in both haploid populations. Based on the sequence information of 'Yu87-1' and 'Zheng58', thirteen markers being polymorphic between the two lines were developed to saturate the qhmf4 region. A total of 8168 H1BC2 (haploid backcross generation) plants produced from 'Yu87-1' and 'Zheng58' were screened for recombinants. All the 48 recombinants were backcrossed to 'Zheng58' to develop H1BC3 progeny. The heterozygous H1BC3 individuals were crossed with CAU5 to induce haploids. In each H1BC3 progeny, haploids were genotyped and evaluated for anther emergence score (AES). Significant (or no significant) difference (P < 0.05) between haploids with or without 'Yu87-1' donor segment indicated presence or absence of qhmf4 in the donor segment. The analysis of the 48 recombinants narrowed the qhmf4 locus down to an ~800 kb interval flanked by markers IND166 and IND1668.

Mean estimation empirical mode decomposition method for terahertz time-domain spectroscopy de-noising.

The wavelet-domain de-noising technique has many applications in terahertz time-domain spectroscopy (THz-TDS). However, it requires a complex procedure for the selection of the optimal wavelet basis and threshold, which varies for different materials. Inappropriate selections can lead to de-noising failure. Here, we propose the Mean Estimation Empirical Mode Decomposition (ME-EMD) de-noising method for THz-TDS. First, the THz-TDS signal and the collected reference noise are decomposed into the intrinsic mode functions (IMFs); second, the maximum and mean absolute values of the noise IMF amplitudes are calculated and defined as the adaptive threshold and adaptive estimated noise value, respectively; finally, these thresholds and estimated noise values are utilized to filter the noise from the signal IMFs and reconstruct the THz-TDS signal. We also calculate the signal-to-noise ratio (SNR) and mean square error (MSE) for the ME-EMD method, the "db7" wavelet basis, and the "sym8" wavelet basis after de-noising in both the simulation and the real sample experiments. Both theoretical analysis and experimental results demonstrated that the new ME-EMD method is a simple, effective, and high-stability de-noising tool for THz-TDS pulses. The measured refractive index curves are compared before and after de-noising and demonstrated that the de-noising process is necessary and useful for measuring the optical constants of a sample.

Study on intelligent recognition detection technology of debond defects for ceramic matrix composites based on terahertz time domain spectroscopy.

With the wide use of high-temperature-resistant ceramic matrix composites (CMCs) in aviation and space flight, it is important to detect the quality of the bonding. This paper used terahertz (THz) time-domain spectroscopy nondestructive testing technology to inspect the bonding defects of the CMC. This paper puts forward a method-extraction method, which is applied to make samples to simulate the bonding defect of CMC by embedding polytetrafluoroethylene (PTFE) sheets with 0.12 mm thickness into the adhesive layer and extracting it after curing and presetting the bonding defects. On the basis of the classical and analytical algorithms, such as the maximum in time-domain and power spectrum integration, through further study in the THz spectral characteristics of bonding samples for CMC, we specifically introduce the upper debond coefficient, lower debond coefficient, average absorption coefficient for the frequency domain, centroid coefficient for the frequency domain, and other characteristics. By optimizing the THz detection characteristics set, as a sample, we adopt the neural network intelligent recognition algorithm to detect the upper and lower debond defects in samples and realize the intelligent identification for CMC debond defects.

Cucumber ECERIFERUM1 (CsCER1), which influences the cuticle properties and drought tolerance of cucumber, plays a key role in VLC alkanes biosynthesis.

Most land plants have a wax layer which covers their aerial parts to protect them from environmental stresses, such as drought, UV radiation, and pathogenic invasion. The wax biosynthesis has been well studied previously in Arabidopsis, but it still remains elusive in cucumber. Here, we isolated a CER1 homolog CsCER1 in cucumber, and we found that the expression of CsCER1 in the cucumber line 3401 which shows waxy fruit phenotype is much higher than that in the cucumber line 3413 which displays glossy fruit phenotype. Spatial and temporal expression analyses revealed that CsCER1 is specifically expressed in the epidermis where waxes are synthesized, and sub-cellular location showed that CsCER1 protein is localized to the endoplasmic reticulum. The expression of CsCER1 can be induced by low temperature, drought, salt stress and abscisic acid. In addition, abnormal expressions of CsCER1 in transgenic cucumber plants have dramatic effects on very-long-chain (VLC) alkanes biosynthesis, cuticle permeability, and drought resistance. Our data suggested that CsCER1 plays an important role in VLC alkanes biosynthesis in cucumber.

Cucumis sativus L. WAX2 Plays a Pivotal Role in Wax Biosynthesis, Influencing Pollen Fertility and Plant Biotic and Abiotic Stress Responses.

Cuticular waxes play an important part in protecting plant aerial organs from biotic and abiotic stresses. In previous studies, the biosynthetic pathway of cuticular waxes and relative functional genes has been researched and understood; however, little is known in cucumber (Cucumis sativus L.). In this study, we cloned and characterized an AtWAX2 homolog, CsWAX2, in cucumber and found that it is highly expressed in the epidermis, where waxes are synthesized, while subcellular localization showed that CsWAX2 protein is localized to the endoplasmic reticulum (ER). The transcriptional expression of CsWAX2 was found to be induced by low temperature, drought, salt stress and ABA, while the ectopic expression of CsWAX2 in an Arabidopsis wax2 mutant could partially complement the glossy stem phenotype. Abnormal expression of CsWAX2 in transgenic cucumbers specifically affected both very long chain (VLC) alkanes and cutin biosynthesis. Furthermore, transgenic cucumber plants of CsWAX2 showed significant changes in pollen viability and fruit resistance to water loss and pathogens compared with the wild type. Collectively, these results indicated that CsWAX2 plays a pivotal role in wax biosynthesis, influencing pollen fertility and the plant's response to biotic and abiotic stresses.

Quantitative Detection of Defects in Multi-Layer Lightweight Composite Structures Using THz-TDS Based on a U-Net-BiLSTM Network.

Multi-layer lightweight composite structures are widely used in the field of aviation and aerospace during the processes of manufacturing and use, and, as such, they inevitably produce defects, damage, and other quality problems, creating the need for timely non-destructive testing procedures and the convenient repair or replacement of quality problems related to the material. When using terahertz non-destructive testing technology to detect defects in multi-layer lightweight composite materials, due to the complexity of their structure and defect types, there are many signal characteristics of terahertz waves propagating in the structures, and there is no obvious rule behind them, resulting in a large gap between the recognition results and the actual ones. In this study, we introduced a U-Net-BiLSTM network that combines the strengths of the U-Net and BiLSTM networks. The U-Net network extracts the spatial features of THz signals, while the BiLSTM network captures their temporal features. By optimizing the network structure and various parameters, we obtained a model tailored to THz spectroscopy data. This model was subsequently employed for the identification and quantitative analysis of defects in multi-layer lightweight composite structures using THz non-destructive testing. The proposed U-Net-BiLSTM network achieved an accuracy of 99.45% in typical defect identification, with a comprehensive F1 score of 99.43%, outperforming the CNN, ResNet, U-Net, and BiLSTM networks. By leveraging defect classification and thickness recognition, this study successfully reconstructed three-dimensional THz defect images, thereby realizing quantitative defect detection.