26 research outputs found

    Temporal flowability evolution of slag-based self-compacting concrete with recycled concrete aggregate

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    The addition of by-products, such as recycled concrete aggregate and ground granulated blast furnace slag, modify the in-fresh flowability of ordinary self-compacting concrete both initially and over time. A detailed study is presented in this paper of 18 mixtures (SF3 slump-flow class) containing 100% coarse recycled concrete aggregate, two types of cement (CEM I or CEM III/A, the latter with 45% ground granulated blast furnace slag), different contents of fine recycled concrete aggregate (0, 50, or 100%), and three different aggregate powders (ultra-fine limestone powder <0.063 mm, limestone fines 0/0.5 mm, and recycled concrete aggregate 0/0.5 mm). The temporal evolution of slump flow, viscosity, and passing ability, and the values of segregation resistance, air content, fresh and hardened density, and compressive strength were evaluated in all the mixtures. The addition of fine recycled concrete aggregate and CEM III/A improved initial slump flow and passing ability by 6%, due to their higher proportion of fines. Nevertheless, the temporal loss of flowability within 60 min was 5.8% lower when adding natural aggregate and CEM I. Viscosity and air content increased 26% on average following additions of fine recycled concrete aggregate, unlike with additions of ground granulated blast furnace slag. Flowability and strength increased with the addition of limestone fines 0/0.5 mm. According to multi-criteria analyses, the mixtures with CEM III/A, 50% fine recycled concrete aggregate, and limestone fines 0/0.5 mm showed an optimal balance between their flowability (SF2 slump-flow class 60 min after the mixing process), compressive strengths (around 60 MPa), and carbon footprints.Spanish Ministry MCIU, AEI and ERDF [grant numbers FPU17/03374 and RTI 2018-097079-B-C31]; the Junta de Castilla y León (Regional Government) and ERDF [grant number UIC-231, BU119P17]; the Youth Employment Initiative (JCyL) and ESF [grant number UBU05B_1274]; the University of Burgos [grant number SUCONS, Y135. GI], UPV/EHU (PPGA20/26) and, finally, our thanks also to the Basque Government research group IT1314-19

    Molecular markers and genetic diversity of Plasmodium vivax

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    Progress in antiandrogen design targeting hormone binding pocket to circumvent mutation based resistance

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    Androgen receptor (AR) plays a critical role in the development and progression of prostate cancer (PCa). Current clinically used antiandrogens such as flutamide, bicalutamide, and newly approved enzalutamide mainly target the hormone binding pocket (HBP) of AR. However, over time, drug resistance invariably develops and switches these antiandrogens from antagonist to agonist of the AR. Accumulated evidence indicates that AR mutation is an important cause for the drug resistance. This review will give an overview of the mutation based resistance of the current clinically used antiandrogens and the rational drug design to overcome the resistance, provides a promising strategy for the development of the new generation of antiandrogens targeting HBP

    Genetic Evidence for O-Specific Antigen as Receptor of Pseudomonas aeruginosa Phage K8 and Its Genomic Analysis

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    Phage therapy requires the comprehensive understanding of the mechanisms underlying the host-phage interactions. In this work, to identify the genes related to Pseudomonas aeruginosa phage K8 receptor synthesis, 16 phage-resistant mutants were selected from a Tn5G transposon mutant library of strain PAK. The disrupted genetic loci were identified and they were related to O-specific antigen (OSA) synthesis, including gene wbpR, ssg, wbpV, wbpO, and Y880_RS05480, which encoded a putative O-antigen polymerase Wzy. The LPS profile of the Y880_RS05480 mutant was analyzed and shown to lack the O-antigen. Therefore, the data from characterization of Y880_RS05480 by TMHMM and SDS-PAGE silver staining analysis suggest that this locus might encode Wzy. The complete phage K8 genome was characterized as 93879 bp in length and contained identical 1188-bp terminal direct repeats. Comparative genomic analysis showed that phage K8 was highly homologous to members of the genus PaP1-like phages. On the basis of our genetic findings, OSA of P. aeruginosa PAK is proven to be the receptor of phage K8. The highly conserved structural proteins among the genetic closely related phages suggest that they may recognize the same receptor

    Exploring potential new floral organ morphogenesis genes of Arabidopsis thaliana using systems biology approach

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    Flowering is one of the important defining features of angiosperms. The initiation of flower development and the formation of different floral organs are the results of the interplays among numerous genes. But until now, just fewer genes have been found linked with flower development. And the functions of lots of genes of Arabidopsis thaliana are still unknown. Although, the quartet model successfully simplified the ABCDE model to elaborate the molecular mechanism by introducing protein-protein interactions (PPIs). We still don't know much about several important aspects of flower development. So we need to discriminate even more genes involving in the flower development. In this study, we identified seven differentially modules through integrating the weighted gene co-expression network analysis (WGCNA) and Support Vector Machine (SVM) method to analyze co-expression network and PPIs using the public floral and non-floral expression profiles data of Arabidopsis thaliana. Gene set enrichment analysis was used for the functional annotation of the related genes, and some of the hub genes were identified in each module. The potential floral organ morphogenesis genes of two significant modules were integrated with PPI information in order to detail the inherent regulation mechanisms. Finally, the functions of the floral patterning genes were elucidated by combining the PPI and evolutionary information. It was indicated that the sub-networks or complexes, rather than the genes, were the regulation unit of flower development. We found that the most possible potential new genes underlining the floral pattern formation in A. thaliana were FY, CBL2, ZFN3 and AT1G77370; among them, FY, CBL2 acted as an upstream regulator of AP2; ZFN3 activated the flower primordial determining gene AP1 and AP2 by HY5/HYH gene via photo induction possibly. And AT1G77370 exhibited similar function in floral morphogenesis, same as ELF3. It possibly formed a complex between RFC3 and RPS15 in cytoplasm, which regulated TSO1 and CPSF160 in the nucleus, to control the floral organ morphogenesis. This process might also be fine tuning by AT5G53360 in the nucleus

    Functional analysis of the sporulation-specific diadenylate cyclase CdaS in Bacillus thuringiensis

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    Cyclic di-AMP (c-di-AMP) is a recently discovered bacterial secondary messenger molecule, which is associated with various physiological functions. In Bacillus, the intracellular level and turnover of c-di-AMP is mainly regulated by three diadenylate cyclases (DACs), including DisA, CdaA and CdaS, and one c-di-AMP-specific phosphodiesterase. In this study, we demonstrated that CdaS protein from B. thuringiensisis is a hexameric DAC protein that can convert ATP or ADP to c-di-AMP in vitro and the N-terminal YojJ domain was essential for the DAC activity. Based on the markerless gene knock-out method, we demonstrated that the transcription of cdaS was initiated by the sporulation-specific sigma factor σH and the deletion of cdaS significantly delayed sporulation and parasporal crystal formation. These findings contrast with similar experiments conducted using B. subtilis, wherein transcription of its cdaS was initiated by the sigma factor σG. Deletion of all the three DAC genes from a single strain was unsuccessful, suggesting that c-di-AMP is an indispensable molecule in B. thuringiensis. Phylogenetic analysis indicated increased diversity of CdaS in the B. cereus and B. subtilis Bacillus subgroups. In summary, this study identifies important aspects in the regulation of c-di-AMP in Bacillus

    SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE 5 in the ecotype Landsberg erecta of Arabidopsis is a functional RD LRR-RLK in regulating brassinosteroid signaling and cell death control

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    In plants, LRR-RLKs play central roles in regulating perception of extracellular signals and initiation of cellular responses under various environmental challenges. Arabidopsis SERK genes, including SERK1 to SERK5, constitute a LRR-RLK sub-family. SERK1, SERK2, SERK3/BAK1 and SERK4/BKK1 have been well characterized to function as crucial regulators in multiple physiological processes such as brassinosteroid signaling, cell death control, pathogenesis, and pollen development. Despite extremely high sequence identity with BKK1, SERK5 is reported to have no functional overlapping with BKK1, which is previously identified to regulate BR and cell death control pathways, probably due to a natural mutation in a highly conserved RD motif in the kinase domain of SERK5 in Col-0 ecotype. Through a gene sequencing analysis in several Arabidopsis accessions, we are able to identify SERK5 in Landsberg erecta (Ler) genome encoding a LRR-RLK with an intact RD motif. Overexpression of SERK5-Ler partially suppresses the BR defective phenotypes of bri1-5 and bak1-3 bkk1-1, indicating SERK5-Ler functions as a positive regulator in BR signaling. Furthermore, the interaction between SERK5-Ler and BRI1 is confirmed by yeast two-hybrid and BiFC assays, and the genetic result showing that elevated expression of a kinase-dead form of SERK5-Ler causes a dominant-negative phenotype in bri1-5. In addition, overexpression of SERK5-Ler is capable of delaying, not completely suppressing, the cell death phenotype of bak1-3 bkk1-1. In this study, we first reveal that SERK5-Ler is a biologically functional component in mediating multiple signaling pathways

    Characterization of Coxsackievirus A6- and Enterovirus 71-associated Hand Foot and Mouth disease in Beijing, China, from 2013 to 2015

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    Background: Etiology surveillance of Hand Foot and Mouth disease (HFMD) in Beijing showed that Coxsackievirus A6 (CVA6) became the major pathogen of HFMD in 2013 and 2015. In order to understand the epidemiological characteristics and clinical manifestations of CVA6-associated HFMD, a comparison study among CVA6-, EV71- (Enterovirus 71) and CVA16- (Coxsackievirus A16) associated HFMD was performed.Methods: Epidemiological characteristics and clinical manifestations among CVA6-, EV71- and CVA16-associated mild or severe cases were compared from 2013 to 2015. VP1 gene of CVA6 and EV71 from mild cases, severe cases were sequenced, aligned and compared with strains from 2009 to 2015 in Beijing and strains available in GenBank. Phylogenetic tree was constructed by neighbor-joining method.Results: CVA6 became the predominant causative agent of HFMD and accounted for 35.4% and 36.9% of total positive cases in 2013 and 2015, respectively. From 2013 to 2015, a total of 305 severe cases and 7 fatal cases were reported. CVA6 and EV71 were responsible for 57.5% of the severe cases. Five out six samples from fatal cases were identified as EV71. High fever, onychomadesis and decrustation were the typical symptoms of CVA6-associated mild HFMD. CVA6-associated severe cases were characterized by high fever with shorter duration and twitch compared with EV71-associated severe cases which were characterized by poor mental condition, abnormal pupil and vomiting. Poor mental condition, lung wet rales, abnormal pupil and tachycardia were the most common clinical features of fatal cases. The percentage of lymphocyte in CVA6-associated cases was significantly lower than that of EV71. High percentage of lymphocyte and low percentage of neutrophils were the typical characteristics of fatal cases. VP1 sequences between CVA6- or EV71-associated mild and severe cases were highly homologous.Conclusion: CVA6 became one of the major pathogens of HFMD in 2013 and 2015 in Beijing. Epidemiological characteristics, clinical manifestations of CVA6-, EV71- and CVA16-associated cases in this study enriched the definition of HFMD caused by different pathogens and shed light to accurate diagnosis, appropriate treatment and effective prevention of HFMD

    Alteration of basal ganglia and right frontoparietal network in early drug-na&#239;ve Parkinson’s disease during heat pain stimuli and resting state

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    Background: The symptoms and pathogenesis of Parkinson’s disease (PD) are complicated and accurate diagnosis is difficult, particularly in early-stage. Functional magnetic resonance imaging is noninvasive and characterized by the integration of different brain areas at functional connectivity (FC). Considering pain process in PD, we hypothesized that pain is one of the earliest symptoms and investigated whether FC of the pain network was disrupted in PD without pain.Methods: Fourteen early drug-naïve PD without pain and 17 age- and sex-matched healthy controls (HC) participated in our test. We investigate abnormalities in FC and in functional network connectivity in PD compared with HC during the task (51 °C heat pain stimuli) and at rest.Results: Compared with HC, PD showed decreased FC in basal ganglia network (BGN), salience network (SN) and sensorimotor network in two states respectively. FNC between the BGN and the SN are reduced during both states in PD compared with HC. In addition, the FNC associated with right frontoparietal network (RFPN) was also significantly disturbed during the task.Conclusion: These findings suggest that BGN plays a role in the pathological mechanisms of pain underlying PD, and RFPN likely contributes greatly to harmonization between intrinsic brain activity and external stimuli
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