306 research outputs found

    Effect of water interactions on Polyvinylamine at different pH for Membrane gas separation

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    Polyvinylamine (PVAm) is a linear polyelectrolyte type of polymer which is water-soluble with highest contents of primary amine. It has been attractive in different fields such as: biomedical applications [1], encapsulation [2], oil recovery [3], and primarily it has extensively been used as a fixed-site–carrier polyvinylamine membrane for carbon dioxide separation and capture. A thin selective layer on polysulfone support for CO2 Separation membranes[4, 5] has been successfully used in composite flat sheet and hollow fiber membranes. The amine group plays the role as the carrier of the gas, increasing the transport performance of the membrane by chemical and physical forces. PVAm composite membrane in dry condition will separate according to solution-diffusion mechanism only. It was however documented by Kim et al. in 2004 [4] that by allowing the membrane to be exposed gas with high relative humidity, the separation performance increased exponentially[4-6]. Through these efforts, it is needed to develop a greater understanding of the relationships between the structure and the interfacial properties of PVAm – water surface. The degree of hydrophilicity manipulation of a given surface necessarily requires understanding the micro-scale principles that, in turn, control the macro-scale surface wetting behavior. See Fig. 1. Please click Additional Files below to see the full abstract

    Should we use the men load–velocity profile for women in deadlift and hip thrust?

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    Injuries are common in team sports and can impact both team and individual performance. In particular, hamstring strain injuries are some of the most common injuries. Furthermore, hamstring injury ratios, in number of injuries and total absence days, have doubled in the last 21 seasons in professional soccer. Weakness in hip extensor strength has been identified as a risk factor in elite-level sprinters. In addition, strength imbalances of the hamstring muscle group seem to be a common cause of hamstring strain injuries. In this regard, velocity-based training has been proposed to analyze deficits in the force–velocity profile. Previous studies have shown differences between men and women, since there are biomechanical and neuromuscular differences in the lower limbs between sexes. Therefore, the aim of this study was to compare the load–velocity profile between males and females during two of the most important hip extension exercises: the hip thrust and the deadlift. Sixteen men and sixteen women were measured in an incremental loading test following standard procedures for the hip thrust and deadlift exercises. Pearson’s correlation (r) was used to measure the strength of the correlation between movement velocity and load (%1RM). The differences in the load–velocity relationship between the men and the women were assessed using a 2 (sex) × 15 (load) repeated-measures ANOVA. The main findings revealed that: (I) the load–velocity relationship was always strong and linear in both exercises (R2 range: 0.88–0.94), (II) men showed higher velocities for light loads (30–50%1RM; effect size: 0.9–0.96) than women for the deadlift, but no significant differences were found for the hip thrust. Based on the results of this study, the load–velocity equations seem to be sex-specific. Therefore, we suggest that using sex-specific equations to analyze deficits in the force–velocity profile would be more effective to control intensity in the deadlift exercis

    Design for additive manufacturing in the medical sector. Tools and cases

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    This work presents a review of the three main axes that constitute the knowledge base when designing products for additive manufacturing in the medical industry: technology, materials and design tools. Through four different study cases of diverse medical products that match the existing categories in the established classification of standards, different design approaches and strategies are presented and suggested as feasible solutions that generate medical products. These cases studies intend to cover some categories where additive manufacturing can be used in the medical sector: a post-surgery protection cast developed using reverse engineering technologies and free-form modelling tools customized not only regarding anatomic shapes but also in terms of aesthetics, a surgical simulator that improves the surgeon’s education process in a non-expensive manner, which could also be shared and spread combining soft and hard parts, a hip surgery retractor designed together with experts that increase the performance of the commercial solutions and a bone replacement implant with an innovative approach that combines engineering polymers with metallic surface coatings. All these case studies present the diversity of possible applications when working with the medical industry, as well as the required skills and knowledge needed to start with this task. Beside this, it has been stated the convenience of engineers to work hand by hand with medical professionals, combining skills and visions to innovate and improve the patient’s journe

    Regulation of extracellular matrix components byAmrZ is mediated by c‑di‑GMP in Pseudomonas ogarae F113

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    The AmrZ/FleQ hub has been identified as a central node in the regulation of environmental adaption in the plant growth-promoting rhizobacterium and model for rhizosphere colonization Pseudomonas ogarae F113. AmrZ is involved in the regulation of motility, biofilm formation, and bis-(3â€Č-5â€Č)-cyclic dimeric guanosine monophosphate (c-di-GMP) turnover, among others, in this bacterium. The mutants in amrZ have a pleiotropic phenotype with distinguishable colony morphology, reduced biofilm formation, increased motility, and are severely impaired in competitive rhizosphere colonization. Here, RNA-Seq and qRT-PCR gene expression analyses revealed that AmrZ regulates many genes related to the production of extracellular matrix (ECM) components at the transcriptional level. Furthermore, overproduction of c-di-GMP in an amrZ mutant, by ectopic production of the Caulobacter crescentus constitutive diguanylate cyclase PleD*, resulted in increased expression of many genes implicated in the synthesis of ECM components. The overproduction of c-di-GMP in the amrZ mutant also suppressed the biofilm formation and motility phenotypes, but not the defect in competitive rhizosphere colonization. These results indicate that although biofilm formation and motility are mainly regulated indirectly by AmrZ, through the modulation of c-di-GMP levels, the implication of AmrZ in rhizosphere competitive colonization occurs in a c-di-GMP-independent manne

    Adaption of Pseudomonas ogarae F113 to the rhizosphere environment—The AmrZ-FleQ Hub

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    Motility and biofilm formation are two crucial traits in the process of rhizosphere colonization by pseudomonads. The regulation of both traits requires a complex signaling network that is coordinated by the AmrZ-FleQ hub. In this review, we describe the role of this hub in the adaption to the rhizosphere. The study of the direct regulon of AmrZ and the phenotypic analyses of an amrZ mutant in Pseudomonas ogarae F113 has shown that this protein plays a crucial role in the regulation of several cellular functions, including motility, biofilm formation, iron homeostasis, and bis-(3â€Č-5â€Č)-cyclic dimeric guanosine monophosphate (c-di-GMP) turnover, controlling the synthesis of extracellular matrix components. On the other hand, FleQ is the master regulator of flagellar synthesis in P. ogarae F113 and other pseudomonads, but its implication in the regulation of multiple traits related with environmental adaption has been shown. Genomic scale studies (ChIP-Seq and RNA-Seq) have shown that in P. ogarae F113, AmrZ and FleQ are general transcription factors that regulate multiple traits. It has also been shown that there is a common regulon shared by the two transcription factors. Moreover, these studies have shown that AmrZ and FleQ form a regulatory hub that inversely regulate traits such as motility, extracellular matrix component production, and iron homeostasis. The messenger molecule c-di-GMP plays an essential role in this hub since its production is regulated by AmrZ and it is sensed by FleQ and required for its regulatory role. This regulatory hub is functional both in culture and in the rhizosphere, indicating that the AmrZ-FleQ hub is a main player of P. ogarae F113 adaption to the rhizosphere environmentWork related to environmental adaption of pseudomonads in the authors’ laboratory is currently funded by a Spanish Ministerio de Ciencia e InnovaciĂłn FEDER/EU Grant PID2021-125070OB-I0

    Transcriptomic analysis of pseudomonas ogarae F113 reveals the antagonistic roles of AmrZ and FleQ during rhizosphere adaption

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    Rhizosphere colonization by bacteria involves molecular and cellular mechanisms, such as motility and chemotaxis, biofilm formation, metabolic versatility, or biosynthesis of secondary metabolites, among others. Nonetheless, there is limited knowledge concerning the main regulatory factors that drive the rhizosphere colonization process. Here we show the importance of the AmrZ and FleQ transcription factors for adaption in the plant growth-promoting rhizobacterium (PGPR) and rhizosphere colonization model Pseudomonas ogarae F113. RNA-Seq analyses of P. ogarae F113 grown in liquid cultures either in exponential and stationary growth phase, and rhizosphere conditions, revealed that rhizosphere is a key driver of global changes in gene expression in this bacterium. Regarding the genetic background, this work has revealed that a mutation in fleQ causes considerably more alterations in the gene expression profile of this bacterium than a mutation in amrZ under rhizosphere conditions. The functional analysis has revealed that in P. ogarae F113, the transcription factors AmrZ and FleQ regulate genes involved in diverse bacterial functions. Notably, in the rhizosphere, these transcription factors antagonistically regulate genes related to motility, biofilm formation, nitrogen, sulfur, and amino acid metabolism, transport, signalling, and secretion, especially the type VI secretion systems. These results define the regulon of two important bifunctional transcriptional regulators in pseudomonads during the process of rhizosphere colonization

    An Orphan VrgG Auxiliary Module Related to the Type VI Secretion Systems from Pseudomonas ogarae F113 Mediates Bacterial Killing

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    The model rhizobacterium Pseudomonas ogarae F113, a relevant plant growth-promoting bacterium, encodes three different Type VI secretion systems (T6SS) in its genome. In silico analysis of its genome revealed the presence of a genetic auxiliary module containing a gene encoding an orphan VgrG protein (VgrG5a) that is not genetically linked to any T6SS structural cluster, but is associated with genes encoding putative T6SS-related proteins: a possible adaptor Tap protein, followed by a putative effector, Tfe8, and its putative cognate immunity protein, Tfi8. The bioinformatic analysis of the VgrG5a auxiliary module has revealed that this cluster is only present in several subgroups of the P. fluorescens complex of species. An analysis of the mutants affecting the vgrG5a and tfe8 genes has shown that the module is involved in bacterial killing. To test whether Tfe8/Tfi8 constitute an effector–immunity pair, the genes encoding Tfe8 and Tfi8 were cloned and expressed in E. coli, showing that the ectopic expression of tfe8 affected growth. The growth defect was suppressed by tfi8 ectopic expression. These results indicate that Tfe8 is a bacterial killing effector, while Tfi8 is its cognate immunity protein. The Tfe8 protein sequence presents homology to the proteins of the MATE family involved in drug extrusion. The Tfe8 effector is a membrane protein with 10 to 12 transmembrane domains that could destabilize the membranes of target cells by the formation of pores, revealing the importance of these effectors for bacterial interaction. Tfe8 represents a novel type of a T6SS effector present in pseudomonadsThis work has been funded by Ministerio de Ciencia e Innovación Grant FEDER/EU Grant PID2021-125070OB-I00. DV was granted by the FPI-UAM program (SFPI/2021-00458

    Analysis of the biodegradative and adaptive potential of the novel polychlorinated biphenyl degrader Rhodococcus sp. WAY2 revealed by its complete genome sequence

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    The complete genome sequence of Rhodococcus sp. WAY2 (WAY2) consists of a circular chromosome, three linear replicons and a small circular plasmid. The linear replicons contain typical actinobacterial invertron-type telomeres with the central CGTXCGC motif. Comparative phylogenetic analysis of the 16S rRNA gene along with phylogenomic analysis based on the genome-togenome blast distance phylogeny (GBDP) algorithm and digital DNA–DNA hybridization (dDDH) with other Rhodococcus type strains resulted in a clear differentiation of WAY2, which is likely a new species. The genome of WAY2 contains five distinct clusters of bph, etb and nah genes, putatively involved in the degradation of several aromatic compounds. These clusters are distributed throughout the linear plasmids. The high sequence homology of the ring-hydroxylating subunits of these systems with other known enzymes has allowed us to model the range of aromatic substrates they could degrade. Further functional characterization revealed that WAY2 was able to grow with biphenyl, naphthalene and xylene as sole carbon and energy sources, and could oxidize multiple aromatic compounds, including ethylbenzene, phenanthrene, dibenzofuran and toluene. In addition, WAY2 was able to co-metabolize 23 polychlorinated biphenyl congeners, consistent with the five different ring-hydroxylating systems encoded by its genome. WAY2 could also use n-alkanes of various chain-lengths as a sole carbon source, probably due to the presence of alkB and ladA gene copies, which are only found in its chromosome. These results show that WAY2 has a potential to be used for the biodegradation of multiple organic compoundsThis research was funded by GREENER-H2020 (EU), grant number 826312, and MICINN/FEDER EU, grant number RTI2018-0933991- B-I00. D.G.-S. was supported by a MECD FPU fellowship program, grant number FPU14/03965. P.S.-L. was supported by the MICINN FPU fellowship program, grant number FPU18/02169. E.B.-R. was supported by the MECD FPU fellowship program, grant number FPU16/05513. J.S., T.C. and O.U. acknowledge Czech Science Foundation grant number 17–00227S, which enabled PCB co-metabolism experiments to be undertake

    Classification of Isolates from the Pseudomonas fluorescens Complex into Phylogenomic Groups Based in Group-Specific Markers.

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    The Pseudomonas fluorescens complex of species includes plant-associated bacteria with potential biotechnological applications in agriculture and environmental protection. Many of these bacteria can promote plant growth by different means, including modification of plant hormonal balance and biocontrol. The P. fluorescens group is currently divided into eight major subgroups in which these properties and many other ecophysiological traits are phylogenetically distributed. Therefore, a rapid phylogroup assignment for a particular isolate could be useful to simplify the screening of putative inoculants. By using comparative genomics on 71 P. fluorescens genomes, we have identified nine markers which allow classification of any isolate into these eight subgroups, by a presence/absence PCR test. Nine primer pairs were developed for the amplification of these markers. The specificity and sensitivity of these primer pairs were assessed on 28 field isolates, environmental samples from soil and rhizosphere and tested by in silico PCR on 421 genomes. Phylogenomic analysis validated the results: the PCR-based system for classification of P. fluorescens isolates has a 98.34% of accuracy and it could be used as a rapid and simple assay to evaluate the potential of any P. fluorescens complex strain.Research was funded by grant BIO2015-64480R from MINECO/FEDER EU. DGS was granted by FPU fellowship program (FPU14/03965) from Ministerio de EducaciĂłn, Cultura y Deporte, Spai
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