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Abstract Ovarian cancer is an extremely malignant gynaecological tumour with a poor patient prognosis and is often associated with chemoresistance. Thus, exploring new therapeutic approaches to improving tumour chemosensitivity is important. The expression of transcription elongation factor B polypeptide 2 (TCEB2) gene is reportedly upregulated in ovarian cancer tumour tissues with acquired resistance, but the specific mechanism involved in tumour resistance remains unclear. In this study, we found that TCEB2 was abnormally highly expressed in cisplatin-resistant tumour tissues and cells. TCEB2 silencing also inhibited the growth and glycolysis of SKOV-3/cisplatin (DDP) and A2780/DDP cells. We further incubated human umbilical vein endothelial cells (HUVECs) with culture supernatants from cisplatin-resistant cells having TCEB2 knockdown. Results revealed that the migration, invasion, and angiogenesis of HUVECs were significantly inhibited. Online bioinformatics analysis revealed that the hypoxia-inducible factor-1A (HIF-1A) protein may bind to TCEB2, and TCEB2 silencing inhibited SKOV-3/DDP cell growth and glycolysis by downregulating HIF1A expression. Similarly, TCEB2 promoted HUVEC migration, invasion, and angiogenesis by upregulating HIF1A expression. In vivo experiments showed that TCEB2 silencing enhanced the sensitivity of ovarian cancer nude mice to cisplatin and that TCEB2 knockdown inhibited the glycolysis and angiogenesis of tumour cells. Our findings can serve as a reference for treating chemoresistant ovarian cancer.

To explore the quality evaluation indicators of walnut and pecan varieties cultured in Yunnan, the contents of 12 nutritional indicators which included in mineral elements, protein, crude fat, and vitamin C of 27 walnut varieties were determined. 12 indicators were comprehensively explored by correlation analysis, principal component analysis and cluster analysis to reveal variation and comprehensive quality of walnut resources in Yunnan Province. Results showed that the variation of the content of 12 indicators was relatively rich, the variation coefficient ranged from 5% to 83%, among which the variation coefficient of vitamin C was the largest and the variation coefficient of crude fat was the smallest. The order of the average contents of 9 mineral elements was K>P>Mg>Ca>Mn>Na>Fe>Zn>Cu. The average contents of protein, fat and vitamin C were 15.62%, 68.63% and 4.66 mg/100 g, respectively. As demonstrated by the results of correlation analysis on 12 indicators, there was a significant positive correlation between protein and P, Fe, Mg, Ca, and Cu. The principal component analysis was used to comprehensively evaluate, showed that the comprehensive quality of walnut varieties 'Xiangcha' 'Yongping' 'Wanshu' and 'Xiaoyuanguo' were the best and the pecan variety 'Kaduo' was the better. The clustering analysis results showed that it can be divided into two major categories, namely the group rich in mineral elements and the group with high fat content. Subsequently, by combining with cluster analysis, K, Fe, Mg, Ca, Cu, protein and fat were determined as the critical indicators to evaluate the quality of walnut and pecan varieties cultured in Yunnan. Pecan varieties were suitable for extracting oil, and 22 main walnut varieties were suitable for direct consumption or the development of functional beverages rich in mineral elements and protein. The study clarified the critical indicators for evaluating the quality of Yunnan walnut and explored its quality characteristics, providing a scientific classification method, and laying a theoretical basis for the construction of the Yunnan walnut quality evaluation system.

Abstract Background This study aimed to evaluate the performance of myocardial blood flow (MBF) and myocardial flow reserve (MFR) for diagnosing coronary artery disease (CAD) using dynamic single‐photon emission computed tomography/computed tomography (SPECT/CT) with a dual‐head rapidly rotating gantry (RRG) and to compare this method with conventional myocardial perfusion imaging (MPI), which can be obtained in a one‐stop manner. Methods A total of 93 patients with suspected or confirmed CAD who underwent RRG SPECT/CT were retrospectively enrolled. They underwent invasive coronary angiography (ICA) and conventional MPI within 3 weeks. Based on the ICA results, the performance of MBF quantitative and semi‐quantitative parameters were compared at patient and vessel levels using ≥50% and ≥75% stenosis as the criteria for CAD diagnosis. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of two types of parameters. Results For patient‐level analysis, the area under ROC curves (AUCs) for stress MBF (sMBF), MFR, summed stress score (SSS), and summed different score (SDS) were 0.971, 0.939, 0.612, and 0.546, respectively, for ≥50% stenosis as positive, and were 0.983, 0.932, 0.735, and 0.509, respectively, for ≥75% stenosis as positive criteria. For vessel‐level analysis, the AUCs of sMBF, MFR, SSS, and SDS were 0.981, 0.933, 0.636, and 0.560, respectively, for ≥50% stenosis as positive and were 0.984, 0.933, 0.767, and 0.583, respectively, for ≥75% stenosis as positive criteria. Conclusions Compared with semi‐quantitative parameters of conventional MPI, MBF quantitative parameters of dual‐head RRG SPECT had higher diagnostic performance for CAD.

The ecological relationships between tree growth and climate factors are important for the adaptation, growth prediction, and forest management of tree species against a background of global warming. Yet how these relationships for drought-sensitive conifer trees are changed and affected by elevation remains unclear. To investigate the effect of elevation on spruce tree growth–climate interactions, we collected a total of 1886 tree-ring cores (two cores per tree) from four spruce species, including Picea crassifolia Kom., Picea meyeri Rehd. et Wils., Picea schrenkiana Fisch. et Mey., and Picea wilsonii Mast., in 10 pure forests at a pair of high- and low-elevation alpine sites with the same slope across two aridity zones in China. We then constructed 20 stand tree-ring chronologies for the low- and high-elevation sites. Overall, the growth of spruce trees was more sensitive to drought variability at sites in the semi-arid zone whereas it was weakly limited by drought in the semi-humid zone. Further, spruce trees growing at high-elevation sites were sensitive to temperature unlike the stronger positive drought responses of those at low-elevation sites. In the latter half of the 20th century, the positive drought–growth relationships of spruce were enhanced at both high and low elevation across both aridity zones due to warming and increased drought intensity. Our dendrochronology-based findings suggest that spruce trees’ radial growth in stands at high elevation may have faced drought stress during three recent decades. Nevertheless, the low-elevation trees incurred stronger drought stress compared to the first half of the 20th century.

Carbon nanotubes (CNTs) are extensively utilized in the fabrication of high-performance composites due to their exceptional mechanical, electrical, and thermal characteristics. To investigate the mechanical properties of CNTs filled polymers accurately and effectively, a 3D modeling approach that incorporates the microstructural attributes of CNTs was introduced. Initially, a representative volume element model was constructed utilizing the modified nearest neighbor algorithm. During the modeling phase, a corresponding interference judgment method was suggested, taking into account the potential positional relationships among the CNTs. Subsequently, stress–strain curves of the model under various loading conditions were derived through finite element analysis employing the volume averaging technique. To validate the efficacy of the modeling approach, the stress within a CNT/epoxy resin composite with varying volume fractions under different axial strains was computed. The resulting stress–strain curves were in good agreement with experimental data from the existing literature. Hence, the modeling method proposed in this study provides a more precise representation of the random distribution of CNTs in the matrix. Furthermore, it is applicable to a broader range of aspect ratios, thereby enabling the CNT simulation model to more closely align with real-world models.

Environmental stresses are the main constraints on agricultural productivity and food security worldwide. This issue is worsened by abrupt and severe changes in global climate. The formation of sugarcane yield and the accumulation of sucrose are significantly influenced by biotic and abiotic stresses. Understanding the biochemical, physiological, and environmental phenomena associated with these stresses is essential to increase crop production. This review explores the effect of environmental factors on sucrose content and sugarcane yield and highlights the negative effects of insufficient water supply, temperature fluctuations, insect pests, and diseases. This article also explains the mechanism of reactive oxygen species (ROS), the role of different metabolites under environmental stresses, and highlights the function of environmental stress-related resistance genes in sugarcane. This review further discusses sugarcane crop improvement approaches, with a focus on endophytic mechanism and consortium endophyte application in sugarcane plants. Endophytes are vital in plant defense; they produce bioactive molecules that act as biocontrol agents to enhance plant immune systems and modify environmental responses through interaction with plants. This review provides an overview of internal mechanisms to enhance sugarcane plant growth and environmental resistance and offers new ideas for improving sugarcane plant fitness and crop productivity.

Plant resistance against biotic stressors is significantly influenced by pathogenesis-related 1 (PR1) proteins. This study examines the systematic identification and characterization of PR1 family genes in sugarcane (Saccharum spontaneum Np-X) and the transcript expression of selected genes in two sugarcane cultivars (ROC22 and Zhongtang3) in response to Ustilago scitaminea pathogen infection. A total of 18 SsnpPR1 genes were identified at the whole-genome level and further categorized into four groups. Notably, tandem and segmental duplication occurrences were detected in one and five SsnpPR1 gene pairs, respectively. The SsnpPR1 genes exhibited diverse physio-chemical attributes and variations in introns/exons and conserved motifs. Notably, four SsnpPR1 (SsnpPR1.02/05/09/19) proteins displayed a strong protein–protein interaction network. The transcript expression of three SsnpPR1 (SsnpPR1.04/06/09) genes was upregulated by 1.2–2.6 folds in the resistant cultivar (Zhongtang3) but downregulated in the susceptible cultivar (ROC22) across different time points as compared to the control in response to pathogen infection. Additionally, SsnpPR1.11 was specifically upregulated by 1.2–3.5 folds at 24–72 h post inoculation (hpi) in ROC22, suggesting that this gene may play an important negative regulatory role in defense responses to pathogen infection. The genetic improvement of sugarcane can be facilitated by our results, which also establish the basis for additional functional characterization of SsnpPR1 genes in response to pathogenic stress.

Sugarcane (Saccharum spp.), a major cash crop that is an important source of sugar and bioethanol, is strongly influenced by the impacts of biotic and abiotic stresses. The intricate polyploid and aneuploid genome of sugarcane has shown various limits for conventional breeding strategies. Nonetheless, biotechnological engineering currently offers the best chance of introducing commercially significant agronomic features. In this study, an efficient Agrobacterium-mediated transformation system that uses the herbicide-resistant CP4-EPSPS gene as a selection marker was developed. Notably, all of the plants that were identified by PCR as transformants showed significant herbicide resistance. Additionally, this transformation protocol also highlighted: (i) the high yield of transgenic lines from calli (each gram of calli generated six transgenic lines); (ii) improved selection; and (iii) a higher transformation efficiency. This protocol provides a reliable tool for a routine procedure for the generation of resilient sugarcane plants.

Polyamide 66 was extensively utilized in various applications contributed by its excellent mechanical performance and outstanding durability. However, its high crystallinity renders it to have low transparency, which seriously limits its application in optical devices. Herein, a highly transparent polyamide (PA) 66-based copolymer was reported using 4,4′-diaminodicyclohexylmethane (PACM), adipic acid, and polyamide 66 salt as the reaction monomers. Wide-angle X-ray diffraction (WAXD) analysis revealed that the crystal phase of the synthesized PA66/PACM6 displayed a clear transition from α to γ as the PACM6 increased accompanied by a decreased intensity in the diffraction peak of the copolymer, whose transmittance was successfully adjusted reaching as high as 92.5% (at 550 nm) when the PACM6 was 40 wt%. Moreover, the copolymer with a higher content of PACM6 exhibited larger toughness. On the other hand, the biaxially oriented films of PA66/PACM6 (20 wt%) were also prepared, and it was found that the transparency of the PA66/PACM6 copolymer could be further enhanced via adjusting the stretching ratio of the film. Furthermore, the mechanical strength of the biaxially oriented PA66/PACM6 was also improved with the increase in the orientation degree in the stretching process, indicating that the physical properties of the transparent PA66 were significantly influenced by its alicyclic structure, and the introduction of PACM into PA66 was capable of effectively improving the optical and crystalline characteristics of PA66, revealing that the synthetic strategy has great potential for guiding the design and development of transparent polyamide materials.

Environmental stresses are the main constraints on agricultural productivity and food security worldwide. This issue is worsened by abrupt and severe changes in global climate. The formation of sugarcane yield and the accumulation of sucrose are significantly influenced by biotic and abiotic stresses. Understanding the biochemical, physiological, and environmental phenomena associated with these stresses is essential to increase crop production. This review explores the effect of environmental factors on sucrose content and sugarcane yield and highlights the negative effects of insufficient water supply, temperature fluctuations, insect pests, and diseases. This article also explains the mechanism of reactive oxygen species (ROS), the role of different metabolites under environmental stresses, and highlights the function of environmental stress-related resistance genes in sugarcane. This review further discusses sugarcane crop improvement approaches, with a focus on endophytic mechanism and consortium endophyte application in sugarcane plants. Endophytes are vital in plant defense; they produce bioactive molecules that act as biocontrol agents to enhance plant immune systems and modify environmental responses through interaction with plants. This review provides an overview of internal mechanisms to enhance sugarcane plant growth and environmental resistance and offers new ideas for improving sugarcane plant fitness and crop productivity. [ABSTRACT FROM AUTHOR]

[Objectives] The paper was to explore the occurrence and mixed infection of sugarcane bacilliform virus disease in Hainan sugarcane-growing area. [Methods] A total of 348 sugarcane leaf samples were collected from 7 sugarcane-growing areas in Hainan Province. Molecular detection of sugarcane bacilliform virus (SCBV) was carried out by PCR using specific primers. [Results] SCBV was detected in 244 out of 348 sugarcane samples, with an average detection rate of 70.11%. The highest detection rate was 76.66% in the Danzhou sugarcane-growing area, while the lowest was 57.14% in the Baisha sugarcane-growing area. The SCBV-positive samples were subjected to testing for SCYLV, SCSMV, SrMV, and SCMV, respectively. The results indicated that 106 out of 244 positive samples exhibited a single infection with SCBV, while 138 samples exhibited mixed infections with SCBV and other sugarcane viruses. The proportion of mixed infections among the SCBV-positive samples was as high as 56.56%. Among the various types of mixed infections, two-virus and three-virus mixed infections were the most prevalent. [Conclusions] SCBV has emerged as a significant threat to the secure production of sugarcane in the Hainan sugarcane-growing region. It presents an explosive infection in the Hainan sugarcane-growing region and frequently combines with other sugarcane viruses to infect sugarcane. The findings of this study wiil provide a theoretical foundation for the prevention and control of sugarcane bacilliform virus disease. [ABSTRACT FROM AUTHOR]