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1.
Sci Rep ; 14(1): 8154, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38589524

RESUMEN

To study the aerodynamic performance and wind-induced response of carbon fiber-reinforced polymer (CFRP) cables, CFRP cable was designed by replacing a steel cable in a tied arch bridge based on stiffness, strength and area equivalent criteria, respectively. The aerodynamic performance and wind-induced response of CFRP cable and steel cable were studied and compared by computational fluid dynamics (CFD) model. Based on the computational results, optimal cable replacement criterion was proposed for CFRP cable to replace steel cable. In addition, surface modification was conducted by engrooving vertical symmetric (VS), vertical asymmetric (VA) and helical symmetric (HS) V-shaped grooves to improve the aerodynamic performance and wind-induced response of CFRP cable. Results showed that CFRP cables exhibited inferior aerodynamic performance and wind-induced response in most cases. However, CFRP cable based on stiffness equivalent criterion exhibited better aerodynamic performance and wind-induced vibration properties compared to the other two cable replacement criteria, thus is regarded as the optimal substitute for steel cable. In addition, HS grooves generated symmetric disturbances and caused approximately equivalent boundary layer separation delays uniformly and continuously along the cable length, thus exhibiting better effect in decreasing the reverse flow region, the maximum negative flow velocity, the vortex shedding frequency and the wind-induced vibration amplitude of CFRP cable. Hence, the stiffness equivalent criterion combined with surface modification with HS V-shaped grooves was proposed to replace steel cable with CFRP cable. This study can provide insights into the aerodynamic performance and wind-induced response of CFRP cable and instructions for cable replacement practice.

2.
BMC Vet Res ; 20(1): 141, 2024 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-38582846

RESUMEN

Glaesserella parasuis, an important respiratory bacterial pathogen, causes Glässer's disease in piglets, with potential immunosuppression. We established a piglet infection model and explored the immunosuppression mechanism to improve our understanding of the host immune response to G. parasuis. Twenty piglets were randomly divided into two groups (n = 10). The infection group was intraperitoneally challenged with 2 × 108 CFU of G. parasuis in 2 mL TSB. The control group was intraperitoneally injected with equivalent TSB. After 72 h, the piglets were sacrificed, and spleen tissue was collected. PD-1/PD-L1 expression was determined. The splenocytes were isolated to detect CD3+ T, CD3+CD4+ T, CD3+CD8+ T and CD3-CD21+cell differentiation. Via data-independent acquisition (DIA), we compared the proteomics of healthy and infected spleen tissues. Glaesserella parasuis modified CD3+ T, CD3+CD4+ T, CD3+CD8+ T and CD3-CD21+ cell differentiation and PD-1/PD-L1 expression in the spleen. The infection group had 596 proteins with significant differences in expression, of which 301 were significantly upregulated and 295 downregulated. Differentially expressed proteins (DEPs) were mainly related to immune responses. This is the first study on PD-1/PD-L1 expression in the spleen associated with immunosuppression in a piglet model to explore the protein changes related to immune responses via DIA.


Asunto(s)
Infecciones por Haemophilus , Haemophilus parasuis , Enfermedades de los Porcinos , Animales , Antígeno B7-H1 , Infecciones por Haemophilus/microbiología , Infecciones por Haemophilus/veterinaria , Terapia de Inmunosupresión/veterinaria , Fosfatidilinositol 3-Quinasas , Receptor de Muerte Celular Programada 1 , Proteínas Proto-Oncogénicas c-akt , Porcinos , Enfermedades de los Porcinos/microbiología , Serina-Treonina Quinasas TOR
3.
HLA ; 103(4): e15453, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38568176

RESUMEN

HLA-C*03:94:02 differs from HLA-C*03:94:01 by a single nucleotide substitution in exon 2 (codon 17 GGA->GGG).


Asunto(s)
Genes MHC Clase I , Antígenos HLA-C , Humanos , Antígenos HLA-C/genética , Alelos , Secuenciación de Nucleótidos de Alto Rendimiento , China
4.
HLA ; 103(2): e15388, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38358085

RESUMEN

Compared with the HLA-C*03:132:01 allele, HLA-C*03:132:02 shows one nucleotide substitution at position 270A>C.


Asunto(s)
Genes MHC Clase I , Antígenos HLA-C , Humanos , Antígenos HLA-C/genética , Alelos , Secuenciación de Nucleótidos de Alto Rendimiento , China
5.
Sensors (Basel) ; 24(2)2024 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-38257707

RESUMEN

Focusing on the problem of strip shape quality control in the finishing process of hot rolling, a shape model based on metal flow and stress release with the application of varying contact rolling parameters is introduced. Combined with digital twin technology, the digital twin framework of the shape model is proposed, which realizes the deep integration between physical time-space and virtual time-space. With the utilization of the historical data, the parameters are optimized iteratively to complete the digital twin of the shape model. According to the schedule, the raw material information is taken as the input to obtain the simulation of the strip shape, which shows a variety of export shape conditions. The prediction absolute error of the crown and flatness are less than 5 µm and 5 I-unit, respectively. The results prove that the proposed shape simulation model with strong prediction performance can be effectively applied to hot rolling production. In addition, the proposed model provides operators with a reference for the parameter settings for actual production and promotes the intelligent application of a shape control strategy.

6.
HLA ; 103(1): e15330, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38081659

RESUMEN

The HLA-C*12:391 allele has three nucleotide substitutions in exon 3 compared to HLA-C*12:44 allele.


Asunto(s)
Genes MHC Clase I , Antígenos HLA-C , Humanos , Antígenos HLA-C/genética , Alelos , Secuenciación de Nucleótidos de Alto Rendimiento , Exones/genética
7.
Plant Commun ; 5(1): 100729, 2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-37798879

RESUMEN

Sesame is an ancient oilseed crop with high oil content and quality. However, the evolutionary history and genetic mechanisms of its valuable agronomic traits remain unclear. Here, we report chromosome-scale genomes of cultivated sesame (Sesamum indicum L.) and six wild Sesamum species, representing all three karyotypes within this genus. Karyotyping and genome-based phylogenic analysis revealed the evolutionary route of Sesamum species from n = 13 to n = 16 and revealed that allotetraploidization occurred in the wild species Sesamum radiatum. Early divergence of the Sesamum genus (48.5-19.7 million years ago) during the Tertiary period and its ancient phylogenic position within eudicots were observed. Pan-genome analysis revealed 9164 core gene families in the 7 Sesamum species. These families are significantly enriched in various metabolic pathways, including fatty acid (FA) metabolism and FA biosynthesis. Structural variations in SiPT1 and SiDT1 within the phosphatidyl ethanolamine-binding protein gene family lead to the genomic evolution of plant-architecture and inflorescence-development phenotypes in Sesamum. A genome-wide association study (GWAS) of an interspecific population and genome comparisons revealed a long terminal repeat insertion and a sequence deletion in DIR genes of wild Sesamum angustifolium and cultivated sesame, respectively; both variations independently cause high susceptibility to Fusarium wilt disease. A GWAS of 560 sesame accessions combined with an overexpression study confirmed that the NAC1 and PPO genes play an important role in upregulating oil content of sesame. Our study provides high-quality genomic resources for cultivated and wild Sesamum species and insights that can improve molecular breeding strategies for sesame and other oilseed crops.


Asunto(s)
Sesamum , Sesamum/genética , Sesamum/metabolismo , Estudio de Asociación del Genoma Completo , Fenotipo , Genómica , Evolución Molecular
8.
HLA ; 103(1): e15289, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37985372

RESUMEN

HLA-A*11:456 has one non-synonymous nucleotide substitution compared to HLA-A*11:02:01:01 at position 565 in exon 3.


Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento , Nucleótidos , Humanos , Alelos , Exones/genética , Antígenos HLA-A/genética
9.
Front Oncol ; 13: 1258287, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37841432

RESUMEN

Background: Immune agents targeting Programmed cell death-1 (PD-1) are a new type of cancer treatment drugs. By inhibiting the interaction between PD-1 and PD-L1, the ability of the immune system to attack tumor cells is enhanced. These immune preparations have shown significant efficacy in the treatment of various malignant tumors. However, like other drugs, immune preparations targeting PD-1 may also cause side effects, including arthralgia. Therefore, we conduct a meta-analysis to assess whether immune-checkpoint inhibitors targeting programmed cell death-1 in lung cancer patients will lead to arthralgia adverse events. Methods: We conducted a comprehensive search across multiple databases, including PubMed, Medline (Ovid), Web of Science, Cochrane, Embase, Scopus, CKNI, Wang fang, VIP database, Sino Med, and Clinical Trails, to identify relevant studies. The search encompassed articles published up until June 20th, 2023. The primary outcome is adverse events about arthralgia and secondary outcomes are any other related with arthralgia. Data extraction was carried out by two independent individuals, and the Cochrane Risk of Bias tool version 2.0 was employed to assess the included studies. The systematic review and meta-analysis were conducted using RevMan 5.3 software. Results: 12 studies are included in the meta-analysis. All included studies were determined to have a low risk of random sequence generation bias. The meta-analysis result showed that arthralgia RR = 1.11, 95% CI [0.88, 1.40], I2 = 56%, back pain RR = 1.86, 95% CI [1.07, 3.26], I2 = 84%, myalgia RR = 0.49, 95% CI [0.27, 0.88], I2 = 86% and muscular pain RR = 1.97, 95% CI [1.40, 2.77], I2 = 23%. Conclusion: The use of targeted inhibitors may lead to an increased incidence of back pain, while potentially reducing the occurrence of myalgia. On the other hand, immune-checkpoint inhibitors targeting programmed cell death-1 in lung cancer patients may not cause arthralgia and muscular pain.

10.
J Adv Res ; 2023 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-37734567

RESUMEN

INTRODUCTION: Whole-genome duplication (WGD) is one of the most sudden and dramatic events rarely reported in invertebrates, but its occurrence can lead to physiological, morphological, and behavioral diversification. WGD has also never been reported in barnacles, which is one of the most unique groups of crustaceans with extremely speciallized morphology (calcareous shells) and habits (intertidal sessile lifestyle). OBJECTIVES: To investigate whether WGD has occurred in barnacles and examine its potential role in driving the adaptive evolution and diversification of barnacles. METHODS: Based on a newly sequenced and assembled chromosome-level barnacle genome, a novel WGD event has been identified in barnacles through a comprehensive analysis of interchromosomal synteny, the Hox gene cluster, and synonymous substitution distribution. RESULTS: We provide ample evidences for WGD in the barnacle genomes. Comparative genomic analysis indicates that this WGD event predates the divergence of Thoracicalcarea, occurring more than 247 million years ago. The retained ohnologs from the WGD are primarily enriched in various pathways related to environmental information processing, shedding light on the adaptive evolution and diversification of intertidal sessile lifestyle. In addition, transcriptomic analyses show that most of these ohnologs were differentially expressed following the ebb of tide. And the cytochrome P450 ohnologs with differential expression patterns are subject to subfunctionalization and/or neofunctionalization for intertidal adaptation. Besides WGD, parallel evolution underlying intertidal adaptation has also occurred in barnacles. CONCLUSION: This study revealed an ancient WGD event in the barnacle genomes, which is potentially associated with the origin and diversification of thoracican barnacles, and may have contributed to the adaptive evolution of their intertidal sessile lifestyle.

11.
J Biosaf Biosecur ; 5(1): 14-20, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36718149

RESUMEN

On December 7, 2022, China adjusted public health control measures, there have been widespread of SARS-CoV-2 infections in Chinese mainland. As the number of infected people increased, the mutation probability of SARS-CoV-2 is also raised. Therefore, it is of great importance to monitor SARS-CoV-2 variants and its mutations in China. In this current study, 665 SARS-CoV-2 genomes from China deposited in the public database were used to analyze the proportion of different variants; to determine the composition of variants in China across different provinces; and analyze specific mutation frequency, focusing on 12 immune escape residues. The results showed that no new mutations were generated on the 12 immune escape residues. The evolutionary analysis of the BF.7 variant circulating in China showed that there is an independent evolutionary branch with unique mutation sites, officially named BF.7.14 by PANGO. This variant may have been imported from Russia to Inner Mongolia at the end of September 2022 and continued its spread in China. The evolutionary analysis of BA.5.2 variant shows that the variant is composed of two sub-variants, named BA.5.2.48 and BA.5.2.49 by PANGO, respectively. This variant may have been imported from abroad to Beijing at the beginning of September 2022 and formed two sub-variants after domestic transmission. Finally, this study showed that current epidemic variants in China were already circulating in other countries, and there were no additional mutations on immune escape residues that could pose a threat to other countries.

12.
Microbiol Spectr ; 10(6): e0180222, 2022 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-36287057

RESUMEN

Bats have attracted global attention because of their zoonotic association with severe acute respiratory syndrome coronavirus (SARS-CoV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Previous and ongoing studies have predominantly focused on bat-borne viruses; however, the prevalence or abundance of bat-borne pathogenic bacteria and their potential public health significance have largely been neglected. For the first time, this study used both metataxonomics (16S rRNA marker gene sequencing) and culturomics (traditional culture methods) to systematically evaluate the potential public health significance of bat fecal pathogenic bacteria. To this end, fecal samples were obtained from five bat species across different locations in China, and their microbiota composition was analyzed. The results revealed that the bat microbiome was most commonly dominated by Proteobacteria, while the strictly anaerobic phylum Bacteroidetes occupied 35.3% of the relative abundance in Rousettus spp. and 36.3% in Hipposideros spp., but less than 2.7% in the other three bat species (Taphozous spp., Rhinolophus spp., and Myotis spp.). We detected 480 species-level phylotypes (SLPs) with PacBio sequencing, including 89 known species, 330 potentially new species, and 61 potentially higher taxa. In addition, a total of 325 species were identified by culturomics, and these were classified into 242 named species and 83 potentially novel species. Of note, 32 of the 89 (36.0%) known species revealed by PacBio sequencing were found to be pathogenic bacteria, and 69 of the 242 (28.5%) known species isolated by culturomics were harmful to people, animals, or plants. Additionally, nearly 40 potential novel species which may be potential bacterial pathogens were identified. IMPORTANCE Bats are one of the most diverse and widely distributed groups of mammals living in close proximity to humans. In recent years, bat-borne viruses and the viral zoonotic diseases associated with bats have been studied in great detail. However, the prevalence and abundance of pathogenic bacteria in bats have been largely ignored. This study used high-throughput sequencing techniques (metataxonomics) in combination with traditional culture methods (culturomics) to analyze the bacterial flora in bat feces from different species of bats in China, revealing that bats are natural hosts of pathogenic bacteria and carry many unknown bacteria. The results of this study can be used as guidance for future investigations of bacterial pathogens in bats.


Asunto(s)
COVID-19 , Quirópteros , Virus , Animales , Humanos , Quirópteros/microbiología , ARN Ribosómico 16S/genética , SARS-CoV-2/genética , Virus/genética , Bacterias/genética , Heces/microbiología , Filogenia
13.
Polymers (Basel) ; 14(17)2022 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-36080521

RESUMEN

The usage of carbon fiber-reinforced polymer (CFRP) to strengthen cracked steel structures can effectively improve its bear capacity, so it has been extensively used in recent years. The degradation of interfacial bonding is one of the most important factors affecting the durability of CFRP-steel structures under a freeze-thaw(F-T)/wet-dry (W-D) environment. In this study, epoxy resin adhesive (ERA) dog-bone specimens and CFRP-steel double-lap joints (bonded joints) were prepared. F-T/W-D cycles experiment and tensile tests of the ERA specimens and the bonded joints were also performed. Under F-T/W-D cycles, the main properties of the ERA specimens and the bonded joints were examined. Results indicated that fracture failure occurred in all ERA specimens. The hybrid failure modes of fiber peeling on the surface of CFRP plate and the bonded interface peeling between the CFRP plate and ERA layer primarily occurred in the bonded joints. The failure of both of them can be considered to be brittle, which was unaffected by the F-T/W-D cycles. With increased F-T/W-D cycles, the ultimate load and tensile strength of the ERA specimens initially increased and then decreased, whereas the elastic modulus initially increased and then remained unchanged. The ultimate load of the bonded joints decreased gradually. Based on the relationship between the interfacial bond-slip parameters and the number of F-T/W-D cycles, the bond-slip model of the bonded joints was established. The proposed relationship was validated by comparing with the experimental bond-slip relationships and the predicted relationships under the F-T/W-D cycles.

14.
Cell Rep ; 40(9): 111308, 2022 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-36044853

RESUMEN

Commensal intestinal bacteria play key roles in regulating host immune tolerance; however, bacterial strains and related metabolites directly involved in this regulation are largely unknown. Here, using a mouse model of dextran sulfate sodium (DSS)-induced colitis combined with different antibiotic treatment, Enterobacter ludwigii, abundant in microbiota of mice treated with metronidazole, is screened out to have prophylactic and therapeutic effects on DSS-induced colitis with or without the presence of complex intestinal bacteria. E. ludwigii is found to induce CD103+DC and regulatory T (Treg)-mediated immune tolerance for colitis remission using in vitro and in vivo experiments. Moreover, choline, one metabolite of E. ludwigii, is identified to increase dendritic cells' (DCs) immune tolerance to promote Treg differentiation. E. ludwigii is found to induce DCs' immune tolerance ability for Treg differentiation through choline and α7nAChR-mediated retinoic acid (RA) and transforming growth factor beta (TGF-ß) upregulation, resulting in protecting mice against DSS-induced colitis. This study suggests potential therapeutic approaches for inflammatory bowel diseases (IBDs).


Asunto(s)
Colina , Colitis , Animales , Colina/metabolismo , Células Dendríticas/metabolismo , Sulfato de Dextran/toxicidad , Modelos Animales de Enfermedad , Enterobacter , Tolerancia Inmunológica , Ratones , Ratones Endogámicos C57BL , Linfocitos T Reguladores
15.
J Biosaf Biosecur ; 4(2): 114-120, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35845149

RESUMEN

Over the past two years, scientists throughout the world have completed more than 6 million SARS-CoV-2 genome sequences. Today, the number of SARS-CoV-2 genomes exceeds the total number of all other viral genomes. These genomes are a record of the evolution of SARS-CoV-2 in the human host, and provide information on the emergence of mutations. In this study, analysis of these sequenced genomes identified 296,728 de novo mutations (DNMs), and found that six types of base substitutions reached saturation in the sequenced genome population. Based on this analysis, a "mutation blacklist" of SARS-CoV-2 was compiled. The loci on the "mutation blacklist" are highly conserved, and these mutations likely have detrimental effects on virus survival, replication, and transmission. This information is valuable for SARS-CoV-2 research on gene function, vaccine design, and drug development. Through association analysis of DNMs and viral transmission rates, we identified 185 DNMs that positively correlated with the SARS-CoV-2 transmission rate, and these DNMs where classified as the "mutation whitelist" of SARS-CoV-2. The mutations on the "mutation whitelist" are beneficial for SARS-CoV-2 transmission and could therefore be used to evaluate the transmissibility of new variants. The occurrence of mutations and the evolution of viruses are dynamic processes. To more effectively monitor the mutations and variants of SARS-CoV-2, we built a SARS-CoV-2 mutation and variant monitoring and pre-warning system (MVMPS), which can monitor the occurrence and development of mutations and variants of SARS-CoV-2, as well as provide pre-warning for the prevention and control of SARS-CoV-2 (https://www.omicx.cn/). Additionally, this system could be used in real-time to update the "mutation whitelist" and "mutation blacklist" of SARS-CoV-2.

16.
Comput Intell Neurosci ; 2022: 9693767, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35655505

RESUMEN

Traffic target tracking is a core task in intelligent transportation system because it is useful for scene understanding and vehicle autonomous driving. Most state-of-the-art (SOTA) multiple object tracking (MOT) methods adopt a two-step procedure: object detection followed by data association. The object detection has made great progress with the development of deep learning. However, the data association still heavily depends on hand crafted constraints, such as appearance, shape, and motion, which need to be elaborately trained for a special object. In this study, a spatial-temporal encoder-decoder affinity network is proposed for multiple traffic targets tracking, aiming to utilize the power of deep learning to learn a robust spatial-temporal affinity feature of the detections and tracklets for data association. The proposed spatial-temporal affinity network contains a two-stage transformer encoder module to encode the features of the detections and the tracked targets at the image level and the tracklet level, aiming to capture the spatial correlation and temporal history information. Then, a spatial transformer decoder module is designed to compute the association affinity, where the results from the two-stage transformer encoder module are fed back to fully capture and encode the spatial and temporal information from the detections and the tracklets of the tracked targets. Thus, efficient affinity computation can be applied to perform data association in online tracking. To validate the effectiveness of the proposed method, three popular multiple traffic target tracking datasets, KITTI, UA-DETRAC, and VisDrone, are used for evaluation. On the KITTI dataset, the proposed method is compared with 15 SOTA methods and achieves 86.9% multiple object tracking accuracy (MOTA) and 85.71% multiple object tracking precision (MOTP). On the UA-DETRAC dataset, 12 SOTA methods are used to compare with the proposed method, and the proposed method achieves 20.82% MOTA and 35.65% MOTP, respectively. On the VisDrone dataset, the proposed method is compared with 10 SOTA trackers and achieves 40.5% MOTA and 74.1% MOTP, respectively. All those experimental results show that the proposed method is competitive to the state-of-the-art methods by obtaining superior tracking performance.


Asunto(s)
Movimiento (Física) , Recolección de Datos
17.
BMC Biol ; 20(1): 113, 2022 05 13.
Artículo en Inglés | MEDLINE | ID: mdl-35562825

RESUMEN

BACKGROUND: The deep-sea may be regarded as a hostile living environment, due to low temperature, high hydrostatic pressure, and limited food and light. Isopods, a species-rich group of crustaceans, are widely distributed across different environments including the deep sea and as such are a useful model for studying adaptation, migration, and speciation. Similar to other deep-sea organisms, giant isopods have larger body size than their shallow water relatives and have large stomachs and fat bodies presumably to store organic reserves. In order to shed light on the genetic basis of these large crustaceans adapting to the oligotrophic environment of deep-sea, the high-quality genome of a deep-sea giant isopod Bathynomus jamesi was sequenced and assembled. RESULTS: B. jamesi has a large genome of 5.89 Gb, representing the largest sequenced crustacean genome to date. Its large genome size is mainly attributable to the remarkable proliferation of transposable elements (84%), which may enable high genome plasticity for adaptive evolution. Unlike its relatives with small body size, B. jamesi has expanded gene families related to pathways of thyroid and insulin hormone signaling that potentially contribute to its large body size. Transcriptomic analysis showed that some expanded gene families related to glycolysis and vesicular transport were specifically expressed in its digestive organs. In addition, comparative genomics and gene expression analyses in six tissues suggested that B. jamesi has inefficient lipid degradation, low basal metabolic rate, and bulk food storage, suggesting giant isopods adopt a more efficient mechanism of nutrient absorption, storage, and utilization to provide sustained energy supply for their large body size. CONCLUSIONS: Taken together, the giant isopod genome may provide a valuable resource for understanding body size evolution and adaptation mechanisms of macrobenthic organisms to deep-sea environments.


Asunto(s)
Isópodos , Adaptación Fisiológica/genética , Animales , Tamaño Corporal , Genoma , Isópodos/genética , Filogenia
18.
Polymers (Basel) ; 14(10)2022 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-35631930

RESUMEN

In this study, we proposed a novel composite anchorage that considers the anchoring performance and dimension simultaneously. The design concept of this composite anchorage was first introduced, followed by comparison with the traditional inner-cone bond-type anchorage and traditional composite anchorage through theoretical and experimental methods. Then, a parametric study was conducted to determine the influence of different parameters on the anchoring performance, and the optimal design parameters were recommended according to the finite element (FE) and test results. Finally, the practicability of the optimal design parameters were validated through experiments on the anchorage with multiple CFRP tendons. Results showed that the novel composite anchorage could improve the anchoring performance compared with the traditional inner-cone bond-type anchorage by promoting increased anchorage efficiency by 60.4% and, with an ideal failure mode of tendon rupture. Moreover, the novel composite anchorage had smaller dimensions and avoided the presence of a vulnerable position at the junction of the mechanical and bond parts compared with the traditional composite anchorage. In addition, a group of optimal design parameters of this composite anchorage with a pre-tightening force of 130 kN, an inclinational differential angle of 0.1°, an inclination angle of 2.9°, and an embedded length of 30 d~40 d were proposed. The composite anchorage with five CFRP tendons designed with the proposed parameters failed with the rupture of the tendons and exhibited an anchoring efficiency of 1.05. This result showed that the optimal parameters were suitable for this novel composite anchorage to grip multiple tendons. This study can provide an experimental and theoretical basis for designing large-tonnage anchorage for multiple FRP tendons used as hangers or cables in real bridges.

19.
J Biosaf Biosecur ; 4(1): 33-37, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35005525

RESUMEN

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved rapidly into new variants throughout the pandemic. The Omicron variant has more than 50 mutations when compared with the original wild-type strain and has been identified globally in numerous countries. In this report, we analyzed the mutational profiles of several variants, including the per-site mutation rate, to determine evolutionary relationships. The Omicron variant was found to have a unique mutation profile when compared with that of other SARS-CoV-2 variants, containing mutations that are rare in clinical samples. Moreover, the presence of five mouse-adapted mutation sites suggests that Omicron may have evolved in a mouse host. Mutations in the Omicron receptor-binding domain (RBD) region, in particular, have potential implications for the ongoing pandemic.

20.
mLife ; 1(3): 311-322, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37732331

RESUMEN

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic resulted in significant societal costs. Hence, an in-depth understanding of SARS-CoV-2 virus mutation and its evolution will help determine the direction of the COVID-19 pandemic. In this study, we identified 296,728 de novo mutations in more than 2,800,000 high-quality SARS-CoV-2 genomes. All possible factors affecting the mutation frequency of SARS-CoV-2 in human hosts were analyzed, including zinc finger antiviral proteins, sequence context, amino acid change, and translation efficiency. As a result, we proposed that when adenine (A) and tyrosine (T) bases are in the context of AM (M stands for adenine or cytosine) or TA motif, A or T base has lower mutation frequency. Furthermore, we hypothesized that translation efficiency can affect the mutation frequency of the third position of the codon by the selection, which explains why SARS-CoV-2 prefers AT3 codons usage. In addition, we found a host-specific asymmetric dinucleotide mutation frequency in the SARS-CoV-2 genome, which provides a new basis for determining the origin of the SARS-CoV-2. Finally, we summarize all possible factors affecting mutation frequency and provide insights into the mutation characteristics and evolutionary trends of SARS-CoV-2.

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