A Theoretical Calculation Model of H-Section Steel Members for Biaxial Bending Moments

Wang Tongtong,Cheng Xin,Du Huibo 한국강구조학회 2024 International Journal of Steel Structures Vol.24 No.1

To investigate the development mechanism of sectional plastic stress and biaxial bending moments of H-section steel members prior to local buckling subjected to monotonic and cyclic loading, extensive parametric analysis models were established in ABAQUS. These models explicitly accounted for diff erent axial force ratios, plate width-thickness ratios under diff erent loading angles, verifying the applicability against existing experimental data. Based on the results of fi nite element analysis, the eff ects of various factors on the development of normal stresses in the cross-section were thoroughly investigated. A semi-empirical semi-theoretical calculation model was established to address biaxial loading in H-section steel members, considering bidirectional displacement, the form of normal stress distribution, and the relationship between the biaxial bending moments. By comparing the model with fi nite element results, it was observed that the model eff ectively predicted the progression of biaxial bending moments development subjected to biaxial loading in H-section steel members. This model provides a more convenient design approach for considering the partial plastic development of the cross-section in bidirectional fl exural design.

Fair Resource Allocation with QoS Guarantee in Secure Multiuser TDMA Networks

Bai, Zhiquan,Wang, Tongtong,Ma, Piming,Ma, Yanbo,Kwak, Kyungsup WILEY INTERSCIENCE 2018 WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Vol.2018 No.-

<P>We investigate a secure multiuser time division multiple access (TDMA) system with statistical delay quality of service (QoS) guarantee in terms of secure effective capacity. An optimal resource allocation policy is proposed to minimize the <TEX>$ \beta $</TEX> -fair cost function of the average user power under the individual QoS constraint, which also balances the energy efficiency and fairness among the users. First, convex optimization problems associated with the resource allocation policy are formulated. Then, a subgradient iteration algorithm based on the Lagrangian duality theory and the dual decomposition theory is employed to approach the global optimal solutions. Furthermore, considering the practical channel conditions, we develop a stochastic subgradient iteration algorithm which is capable of dynamically learning the intended wireless channels and acquiring the global optimal solution. It is shown that the proposed optimal resource allocation policy depends on the delay QoS requirement and the channel conditions. The optimal policy can save more power and achieve the balance of the energy efficiency and the fairness compared with the other resource allocation policies.</P>

Dietary methionine supplementation to a low-protein diet improved hair follicle development of Angora rabbits

Zhao Man,Wang Tongtong,Wang Bin,Liu Chuanhua,Li Fuchang,Liu Lei 아세아·태평양축산학회 2023 Animal Bioscience Vol.36 No.6

Objective: Angora rabbits fed a low-protein diet exhibit decreased hair production performance. This study was set out to evaluate the effects of methionine on hair properties and nitrogen metabolism in Angora rabbits fed a low-protein diet and to investigate the gene expression related to hair follicle development to determine the possible molecular mechanism of methionine effects on hair follicle development. Methods: An experiment was conducted to investigate the effects of DL-methionine addition on a low-protein diet on hair development in Angora rabbits. Angora rabbits were divided into 5 groups: fed a normal diet (control), fed a low-protein diet (LP), or fed an LP supplemented with 0.2%, 0.4%, or 0.6% DL-methionine (Met). Results: The results showed that rabbits in the LP group had lower wool yield than the control rabbits, but the addition of 0.4% to 0.6% Met to LP attenuated these effects (p< 0.05). Dietary addition of 0.4% to 0.6% Met to LP increased the apparent nitrogen digestibility, nitrogen utilization rate, and feed efficiency (p<0.05). Feeding LP decreased the insulinlike growth factor 1 (IGF1), keratin-associated protein (KAP) 3.1, and KAP 6.1 mRNA levels compared with the control, but the addition of 0.4% Met in LP attenuated these effects (p<0.05). Relative to the LP or control group, dietary addition of 0.4% Met increased versican mRNA levels. Conclusion: In conclusion, the addition of Met to LP could improves wool production performance and feed efficiency and reduce nitrogen emissions in Angora rabbits. Met can promote hair follicle development, which may be associated with IGF1, KAP, and the versican signaling.

Parameters study on lateral buckling of submarine PIP pipelines

Zhang, Xinhu,Duan, Menglan,Wang, Yingying,Li, Tongtong Techno-Press 2016 Ocean systems engineering Vol.6 No.1

In meeting the technical needs for deepwater conditions and overcoming the shortfalls of single-layer pipes for deepwater applications, pipe-in-pipe (PIP) systems have been developed. While, for PIP pipelines directly laid on the seabed or with partial embedment, one of the primary service risks is lateral buckling. The critical axial force is a key factor governing the global lateral buckling response that has been paid much more attention. It is influenced by global imperfections, submerged weight, stiffness, pipe-soil interaction characteristics, et al. In this study, Finite Element Models for imperfect PIP systems are established on the basis of 3D beam element and tube-to-tube element in Abaqus. A parameter study was conducted to investigate the effects of these parameters on the critical axial force and post-buckling forms. These parameters include structural parameters such as imperfections, clearance, and bulkhead spacing, pipe/soil interaction parameter, for instance, axial and lateral friction properties between pipeline and seabed, and load parameter submerged weight. Python as a programming language is been used to realize parametric modeling in Abaqus. Some conclusions are obtained which can provide a guide for the design of PIP pipelines.

Genome-wide locus-specific DNA methylation repatterning may facilitate rapid evolution of mercury resistance in rice

Cong Weixuan,Li Ning,Wang Jinbin,Kang Ying,Miao Yiling,Xu Chunming,Wang Ziqi,Liu Tongtong,Gong Lei,Liu Bao,Ou Xiufang 한국유전학회 2022 Genes & Genomics Vol.44 No.3

Background: Albeit a relatively stable epigenetic modification, DNA methylation in plants can be repatterned and play important roles in response to biotic and abiotic stresses. However, whether DNA methylation dynamics may contribute to cope with mercury (Hg) stress in plants remains to be fully investigated. Objective: To probe the potential roles of DNA methylation dynamics in coping with Hg stress in rice. Methods: Whole-genome bisulfite sequencing was used to profile the DNA methylation patterns of a rice Hg-resistant line (RHg) selected from a heterozygous mutant of the DNA methyltransferase 1 gene (OsMET1+/-), together with its Hg-sensitive wild-type plants of cv. Nipponbare (Nip) under both normal and Hg stress conditions. Results: Genome-wide locus-specific differential methylation regions (DMRs) were detected between RHg and Nip under normal condition, the predominant DMR patterns were CG hypo-DMRs, CHG hypo-DMRs and CHH hyper-DMRs. In both lines, more hyper- than hypo-DMRs were detected at all three sequence contexts (CG, CHG and CHH) under Hg stress relative to normal condition. Comparison of DNA methylation changes in the two lines under Hg stress indicates that RHg had a more dynamic methylome than the control (Nip). Original DMRs in RHg trended to transform to opposite status (from hyper- to hypo- or vice versa) under Hg stress condition. Gene ontology analysis revealed that Hg-resistance-related DMGs were enriched in diverse biological processes. Conclusions: Our results suggest genome-wide locus-specific DNA methylation repatterning can facilitate rapid acquisition of Hg resistance in rice.

Variations in bacterial and fungal communities through soil depth profiles in a Betula albosinensis forest

Can Du,Zengchao Geng,Qiang Wang,Tongtong Zhang,Wenxiang He,Lin Hou,Yueling Wang 한국미생물학회 2017 The journal of microbiology Vol.55 No.9

Microbial communities in subsurface soil are specialized for their environment, which is distinct from that of the surface communities. However, little is known about the microbial communities (bacteria and fungi) that exist in the deeper soil horizons. Vertical changes in microbial alpha-diversity (Chao1 and Shannon indices) and community composition were investigated at four soil depths (0–10, 10–20, 20–40, and 40–60 cm) in a natural secondary forest of Betula albosinensis by high-throughput sequencing of the 16S and internal transcribed spacer rDNA regions. The numbers of operational taxonomic units (OTUs), and the Chao1 and Shannon indices decreased in the deeper soil layers. Each soil layer contained both mutual and specific OTUs. In the 40–60 cm soil layer, 175 and 235 specific bacterial and fungal OTUs were identified, respectively. Acidobacteria was the most dominant bacterial group in all four soil layers, but reached its maximum at 40–60 cm (62.88%). In particular, the 40–60 cm soil layer typically showed the highest abundance of the fungal genus Inocybe (47.46%). The Chao1 and Shannon indices were significantly correlated with the soil organic carbon content. Redundancy analysis indicated that the bacterial communities were closely correlated with soil organic carbon content (P = 0.001). Collectively, these results indicate that soil nutrients alter the microbial diversity and relative abundance and affect the microbial composition.

Hepatocellular carcinoma prediction model performance decreases with long-term antiviral therapy in chronic hepatitis B patients

Xiaoning Wu,Xiaoqian Xu,Jialing Zhou,Yameng Sun,Huiguo Ding,Wen Xie,Guofeng Chen,Anlin Ma,Hongxin Piao,Bingqiong Wang,Shuyan Chen,Tongtong Meng,Xiaojuan Ou,Hwai-I Yang,Jidong Jia,Yuanyuan Kong,Hong Yo 대한간학회 2023 Clinical and Molecular Hepatology(대한간학회지) Vol.29 No.3

Background/Aims: Existing hepatocellular carcinoma (HCC) prediction models are derived mainly from pretreatment or early on-treatment parameters. We reassessed the dynamic changes in the performance of 17 HCC models in patients with chronic hepatitis B (CHB) during long-term antiviral therapy (AVT). Methods: Among 987 CHB patients administered long-term entecavir therapy, 660 patients had 8 years of follow-up data. Model scores were calculated using on-treatment values at 2.5, 3, 3.5, 4, 4.5, and 5 years of AVT to predict threeyear HCC occurrence. Model performance was assessed with the area under the receiver operating curve (AUROC). The original model cutoffs to distinguish different levels of HCC risk were evaluated by the log-rank test. Results: The AUROCs of the 17 HCC models varied from 0.51 to 0.78 when using on-treatment scores from years 2.5 to 5. Models with a cirrhosis variable showed numerically higher AUROCs (pooled at 0.65–0.73 for treated, untreated, or mixed treatment models) than models without (treated or mixed models: 0.61–0.68; untreated models: 0.51–0.59). Stratification into low, intermediate, and high-risk levels using the original cutoff values could no longer reflect the true HCC incidence using scores after 3.5 years of AVT for models without cirrhosis and after 4 years of AVT for models with cirrhosis. Conclusions: The performance of existing HCC prediction models, especially models without the cirrhosis variable, decreased in CHB patients on long-term AVT. The optimization of existing models or the development of novel models for better HCC prediction during long-term AVT is warranted.

Occurrence, evolution, and functions of DNA phosphorothioate epigenetics in bacteria

Tong, Tong,Chen, Si,Wang, Lianrong,Tang, You,Ryu, Jae Yong,Jiang, Susu,Wu, Xiaolin,Chen, Chao,Luo, Jie,Deng, Zixin,Li, Zhiqiang,Lee, Sang Yup,Chen, Shi National Academy of Sciences 2018 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.115 No.13

<P><B>Significance</B></P><P>Phosphorothioate (PT) modification of the DNA sugar-phosphate backbone is an important microbial epigenetic modification governed by DndABCDE, which together with DndFGH, constitutes a restriction-modification system. We show that up to 45% of 1,349 identified bacterial <I>dnd</I> systems exhibit the form of solitary <I>dndABCDE</I> without the restriction counterparts of <I>dndFGH</I>. The combination of epigenomics, transcriptome analysis, and metabolomics suggests that in addition to providing a genetic barrier against invasive DNA, PT modification is a versatile player involved in the epigenetic control of gene expression and the maintenance of cellular redox homeostasis. This finding provides evolutionary and functional insights into this unusual epigenetic modification. Our results imply that PT systems might evolve similar to other epigenetic modification systems with multiple cellular functions.</P><P>The chemical diversity of physiological DNA modifications has expanded with the identification of phosphorothioate (PT) modification in which the nonbridging oxygen in the sugar-phosphate backbone of DNA is replaced by sulfur. Together with DndFGH as cognate restriction enzymes, DNA PT modification, which is catalyzed by the DndABCDE proteins, functions as a bacterial restriction-modification (R-M) system that protects cells against invading foreign DNA. However, the occurrence of <I>dnd</I> systems across a large number of bacterial genomes and their functions other than R-M are poorly understood. Here, a genomic survey revealed the prevalence of bacterial <I>dnd</I> systems: 1,349 bacterial <I>dnd</I> systems were observed to occur sporadically across diverse phylogenetic groups, and nearly half of these occur in the form of a solitary <I>dndBCDE</I> gene cluster that lacks the <I>dndFGH</I> restriction counterparts. A phylogenetic analysis of 734 complete PT R-M pairs revealed the coevolution of M and R components, despite the observation that several PT R-M pairs appeared to be assembled from M and R parts acquired from distantly related organisms. Concurrent epigenomic analysis, transcriptome analysis, and metabolome characterization showed that a solitary PT modification contributed to the overall cellular redox state, the loss of which perturbed the cellular redox balance and induced <I>Pseudomonas fluorescens</I> to reconfigure its metabolism to fend off oxidative stress. An in vitro transcriptional assay revealed altered transcriptional efficiency in the presence of PT DNA modification, implicating its function in epigenetic regulation. These data suggest the versatility of PT in addition to its involvement in R-M protection.</P>