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1.
Appl Opt ; 63(16): 4310-4316, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38856608

ABSTRACT

Recently, a novel technique was proposed for recovering the complex amplitude of an optical field from a set of interferograms modulated in both visibility and phase steps for the synchronous case, named amplitude-phase-shifting interferometry (APSI). This requirement leads to errors in the accuracy of phase recovery due to miscalibration or the nonlinear response of the device used to generate the phase steps; in the APSI case, these are polarizers. In this paper, we propose to create a generalized model of the APSI technique where the phase steps can be different from each other. APSI has been successfully implemented in a Mach-Zehnder interferometer, while the present technique has been deployed in a double-aperture common-path interferometer (DACPI). Additionally, it is demonstrated that in a DACPI, the use of experimental elements that may cause aberrations or extra noise in the experimental results is reduced. The aim is to have an even more robust phase and amplitude recovery technique, now named generalized amplitude-phase-shifting interferometry. Experimental results are presented and validated through a numerical noise study.

2.
Planta ; 257(1): 12, 2022 Dec 15.
Article in English | MEDLINE | ID: mdl-36520227

ABSTRACT

MAIN CONCLUSION: ScHINT1 was identified at sugarcane SAM using subtractive libraries. Here, by bioinformatic tools, two-hybrid approach, and biochemical assays, we proposed that its role might be associated to control redox homeostasis. Such control is important for plant development and flowering transition, and this is ensured with some protein partners such as PAL and SBT that interact with ScHINT1. The shoot apical meristem transition from vegetative to reproductive is a crucial step for plants. In sugarcane (Saccharum spp.), this process is not well known, and it has an important impact on production due to field reduction. In view of this, ScHINT1 (Sugarcane HISTIDINE TRIAD NUCLEOTIDE-BINDING PROTEIN) was identified previously by subtractive cDNA libraries using Shoot Apical Meristem (SAM) by our group. This protein is a member of the HIT superfamily that was composed of hydrolase with an AMP site ligation. To better understand the role of ScHINT1 in sugarcane flowering, here its function in SAM was characterized using different approaches such as bioinformatics, two-hybrid assays, transgenic plants, and biochemical assays. ScHINT1 was conserved in plants, and it was grouped into four clades (HINT1, HINT2, HINT3, and HINT4). The 3D model proposed that ScHINT1 might be active as it was able to ligate to AMP subtract. Moreover, the two-hybrid approach identified two protein interactions: subtilase and phenylalanine ammonia-lyase. The evolutionary tree highlighted the relationships that each sequence has with specific subfamilies and different proteins. The 3D models constructed reveal structure conservation when compared with other PDB-related crystals, which indicates probable functional activity for the sugarcane models assessed. The interactome analysis showed a connection to different proteins that have antioxidative functions in apical meristems. Lastly, the transgenic plants with 35S::ScHINT1_AS (anti-sense orientation) produced more flowers than wild-type or 35S::ScHINT1_S (sense). Alpha-tocopherol and antioxidant enzymes measurement showed that their levels were higher in 35S::ScHINT_S plants than in 35S::ScHINT1_AS or wild-type plants. These results proposed that ScHINT1 might have an important role with other proteins in orchestrating this complex network for plant development and flowering.


Subject(s)
Flowers , Meristem , Meristem/genetics , Plants, Genetically Modified/genetics , Homeostasis , Oxidation-Reduction , Adenosine Monophosphate/metabolism , Gene Expression Regulation, Plant
3.
Int J Mol Sci ; 23(15)2022 Aug 01.
Article in English | MEDLINE | ID: mdl-35955667

ABSTRACT

Gluconacetobacter diazotrophicus has been the focus of several studies aiming to understand the mechanisms behind this endophytic diazotrophic bacterium. The present study is the first global analysis of the early transcriptional response of exponentially growing G. diazotrophicus to iron, an essential cofactor for many enzymes involved in various metabolic pathways. RNA-seq, targeted gene mutagenesis and computational motif discovery tools were used to define the G. diazotrophicusfur regulon. The data analysis showed that genes encoding functions related to iron homeostasis were significantly upregulated in response to iron limitations. Certain genes involved in secondary metabolism were overexpressed under iron-limited conditions. In contrast, it was observed that the expression of genes involved in Fe-S cluster biosynthesis, flagellar biosynthesis and type IV secretion systems were downregulated in an iron-depleted culture medium. Our results support a model that controls transcription in G. diazotrophicus by fur function. The G. diazotrophicusfur protein was able to complement an E. colifur mutant. These results provide new insights into the effects of iron on the metabolism of G. diazotrophicus, as well as demonstrate the essentiality of this micronutrient for the main characteristics of plant growth promotion by G. diazotrophicus.


Subject(s)
Gluconacetobacter , Iron , Bacterial Proteins/metabolism , Culture Media/pharmacology , Iron/metabolism , Transcriptome
4.
Purinergic Signal ; 16(4): 503-518, 2020 12.
Article in English | MEDLINE | ID: mdl-33025424

ABSTRACT

Caffeine, a stimulant largely consumed around the world, is a non-selective adenosine receptor antagonist, and therefore caffeine actions at synapses usually, but not always, mirror those of adenosine. Importantly, different adenosine receptors with opposing regulatory actions co-exist at synapses. Through both inhibitory and excitatory high-affinity receptors (A1R and A2R, respectively), adenosine affects NMDA receptor (NMDAR) function at the hippocampus, but surprisingly, there is a lack of knowledge on the effects of caffeine upon this ionotropic glutamatergic receptor deeply involved in both positive (plasticity) and negative (excitotoxicity) synaptic actions. We thus aimed to elucidate the effects of caffeine upon NMDAR-mediated excitatory post-synaptic currents (NMDAR-EPSCs), and its implications upon neuronal Ca2+ homeostasis. We found that caffeine (30-200 µM) facilitates NMDAR-EPSCs on pyramidal CA1 neurons from Balbc/ByJ male mice, an action mimicked, as well as occluded, by 1,3-dipropyl-cyclopentylxantine (DPCPX, 50 nM), thus likely mediated by blockade of inhibitory A1Rs. This action of caffeine cannot be attributed to a pre-synaptic facilitation of transmission because caffeine even increased paired-pulse facilitation of NMDA-EPSCs, indicative of an inhibition of neurotransmitter release. Adenosine A2ARs are involved in this likely pre-synaptic action since the effect of caffeine was mimicked by the A2AR antagonist, SCH58261 (50 nM). Furthermore, caffeine increased the frequency of Ca2+ transients in neuronal cell culture, an action mimicked by the A1R antagonist, DPCPX, and prevented by NMDAR blockade with AP5 (50 µM). Altogether, these results show for the first time an influence of caffeine on NMDA receptor activity at the hippocampus, with impact in neuronal Ca2+ homeostasis.


Subject(s)
Caffeine/pharmacology , Hippocampus/drug effects , Neurons/drug effects , Purinergic P1 Receptor Antagonists/pharmacology , Synaptic Transmission/drug effects , Animals , Excitatory Postsynaptic Potentials/drug effects , Glutamine , Hippocampus/metabolism , Male , Mice , Neurons/metabolism , Rats , Rats, Sprague-Dawley , Receptors, N-Methyl-D-Aspartate/metabolism
5.
Int J Mol Sci ; 21(1)2020 Jan 03.
Article in English | MEDLINE | ID: mdl-31947822

ABSTRACT

BACKGROUND: Inoculation with Gluconacetobacter diazotrophicus has shown to influence root development in red rice plants, and more recently, the induced systemic tolerance (IST) response to drought was also demonstrated. The goal of this study was to evaluate the inoculation effect of G. diazotrophicus strain Pal5 on the amelioration of drought stress and root development in red rice (Oryza sativa L.). METHODS: The experimental treatments consist of red rice plants inoculated with and without strain Pal5 in presence and absence of water restriction. Physiological, biochemical, and molecular analyses of plant roots were carried out, along with measurements of growth and biochemical components. RESULTS: The plants showed a positive response to the bacterial inoculation, with root growth promotion and induction of tolerance to drought. An increase in the root area and higher levels of osmoprotectant solutes were observed in roots. Bacterial inoculation increased the drought tolerance and positively regulated certain root development genes against the water deficit in plants. CONCLUSION: G. diazotrophicus Pal5 strain inoculation favored red rice plants by promoting various root growth and developmental mechanisms against drought stress, enabling root development and improving biochemical composition.


Subject(s)
Gluconacetobacter/physiology , Oryza/microbiology , Plant Roots/microbiology , Droughts , Oryza/growth & development , Plant Roots/growth & development , Stress, Physiological , Symbiosis , Water/metabolism
6.
Molecules ; 23(2)2018 Feb 17.
Article in English | MEDLINE | ID: mdl-29462992

ABSTRACT

Alkaline phytases from uncultured microorganisms, which hydrolyze phytate to less phosphorylated myo-inositols and inorganic phosphate, have great potential as additives in agricultural industry. The development of metagenomics has stemmed from the ineluctable evidence that as-yet-uncultured microorganisms represent the vast majority of organisms in most environments on earth. In this study, a gene encoding a phytase was cloned from red rice crop residues and castor bean cake using a metagenomics strategy. The amino acid identity between this gene and its closest published counterparts is lower than 60%. The phytase was named PhyRC001 and was biochemically characterized. This recombinant protein showed activity on sodium phytate, indicating that PhyRC001 is a hydrolase enzyme. The enzymatic activity was optimal at a pH of 7.0 and at a temperature of 35 °C. ß-propeller phytases possess great potential as feed additives because they are the only type of phytase with high activity at neutral pH. Therefore, to explore and exploit the underlying mechanism for ß-propeller phytase functions could be of great benefit to biotechnology.


Subject(s)
6-Phytase/genetics , Bacteria/enzymology , Metagenomics , 6-Phytase/antagonists & inhibitors , 6-Phytase/chemistry , Amino Acid Sequence , Bacteria/genetics , Environment , Enzyme Stability/drug effects , Gene Library , Genes, Bacterial , Hydrogen-Ion Concentration , Ions , Metals/pharmacology , Models, Molecular , Phylogeny , Recombinant Proteins/isolation & purification , Sequence Analysis, DNA , Structural Homology, Protein , Substrate Specificity/drug effects , Temperature
7.
Molecules ; 21(7)2016 Jun 25.
Article in English | MEDLINE | ID: mdl-27347917

ABSTRACT

Many naturally-occurring cellulolytic microorganisms are not readily cultivable, demanding a culture-independent approach in order to study their cellulolytic genes. Metagenomics involves the isolation of DNA from environmental sources and can be used to identify enzymes with biotechnological potential from uncultured microbes. In this study, a gene encoding an endoglucanase was cloned from red rice crop residues using a metagenomic strategy. The amino acid identity between this gene and its closest published counterparts is lower than 70%. The endoglucanase was named EglaRR01 and was biochemically characterized. This recombinant protein showed activity on carboxymethylcellulose, indicating that EglaRR01 is an endoactive lytic enzyme. The enzymatic activity was optimal at a pH of 6.8 and at a temperature of 30 °C. Ethanol production from this recombinant enzyme was also analyzed on EglaRR01 crop residues, and resulted in conversion of cellulose from red rice into simple sugars which were further fermented by Saccharomyces cerevisiae to produce ethanol after seven days. Ethanol yield in this study was approximately 8 g/L. The gene found herein shows strong potential for use in ethanol production from cellulosic biomass (second generation ethanol).


Subject(s)
Cellulase/genetics , Cellulase/metabolism , Cellulose/metabolism , Cloning, Molecular , Gene Expression , Genomics , Oryza/genetics , Oryza/metabolism , Biomass , Cellulase/isolation & purification , Enzyme Activation , Ethanol/metabolism , Fermentation , Genomics/methods , Hydrogen-Ion Concentration , Recombinant Proteins/genetics , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Temperature
8.
Bol Asoc Med P R ; 106(3): 43-7, 2014.
Article in Spanish | MEDLINE | ID: mdl-25470910

ABSTRACT

Brain gliosarcoma is a rare variant of glioblastoma multiforme that occurs primarily between the sixth and seventh decades of life. Few cases have been reported in patients younger than nineteen years. We report a four-year-old male with clinical, imaging and pathology compatible with brain gliosarcoma. Beside surgery he was managed with adjuvant radiotherapy and after follow-up is free of recurrence or neurologic deficit. Brain gliosarcoma is highly aggressive and the median survival is related to the extent of surgical resection.


Subject(s)
Brain Neoplasms/pathology , Gliosarcoma/pathology , Brain Neoplasms/therapy , Child, Preschool , Follow-Up Studies , Gliosarcoma/therapy , Humans , Male , Radiotherapy, Adjuvant/methods
9.
Front Plant Sci ; 15: 1345379, 2024.
Article in English | MEDLINE | ID: mdl-38344184

ABSTRACT

Common bean (Phaseolus vulgaris) can efficiently fix atmospheric nitrogen when associated with Rhizobia. However, drought stress impairs plant metabolic processes, especially the biological nitrogen fixation (BNF). Here, we assessed transcriptional responses in nodules of two common bean genotypes to drought stress under BNF reliance. The RNA-Seq analysis yielded a total of 81,489,262 and 72,497,478 high quality reads for Negro Argel and BAT 477 genotypes, respectively. The reads were mapped to the Phaseolus vulgaris reference genome and expression analysis identified 145 and 1451 differentially expressed genes (DEGs) for Negro Argel and BAT 477 genotypes, respectively. Although BAT 477 had more DEGs, both genotypes shared certain drought-responsive genes, including an up-regulated heat shock protein (HSP) and a down-regulated peroxidase, indicating shared pathways activated during drought in nodule tissue. Functional analysis using MapMan software highlighted the up-regulation of genes involved in abiotic stress responses, such as HSPs and specific transcription factors (TFs), in both genotypes. There was a significant down-regulation in metabolic pathways related to antioxidant protection, hormone signaling, metabolism, and transcriptional regulation. To validate these findings, we conducted RT-qPCR experiments for ten DEGs in nodules from both genotypes, for which the expression profile was confirmed, thus reinforcing their functional relevance in the nodule responses to drought stress during BNF. BAT 477 genotype exhibited more pronounced response to drought, characterized by a high number of DEGs. The strong down-regulation of DEGs leads to transcriptional disturbances in several pathways related to stress acclimation such as hormone and antioxidant metabolism. Additionally, we identified several genes that are known to play key roles in enhancing drought tolerance, such as HSPs and crucial TFs. Our results provide new insights into the transcriptional responses in root-nodules, an underexplored tissue of plants mainly under drought conditions. This research paves the way for potential improvements in plant-bacteria interactions, contributing to common bean adaptations in the face of challenging environmental conditions.

10.
Mol Plant Microbe Interact ; 26(8): 937-45, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23634840

ABSTRACT

Gluconacetobacter diazotrophicus is an aerobic diazotrophic plant-growth-promoting bacterium isolated from different gramineous plants. We showed that reactive oxygen species (ROS) were produced at early stages of rice root colonization, a typical plant defense response against pathogens. The transcription of the pathogen-related-10 gene of the jasmonic acid (JA) pathway but not of the PR-1 gene of the salicylic acid pathway was activated by the endophytic colonization of rice roots by G. diazotrophicus strain PAL5. Quantitative polymerase chain reaction analyses showed that, at early stages of colonization, the bacteria upregulated the transcript levels of ROS-detoxifying genes such as superoxide dismutase (SOD) and glutathione reductase (GR). To proof the role of ROS-scavenging enzymes in the colonization and interaction process, transposon insertion mutants of the SOD and GR genes of strain PAL5 were constructed. The SOD and GR mutants were unable to efficiently colonize the roots, indicated by the decrease of tightly root-associated bacterial cell counts and endophytic colonization and by fluorescence in situ hybridization analysis. Interestingly, the mutants did not induce the PR-10 of the JA-pathway, probably due to the inability of endophytic colonization. Thus, ROS-scavenging enzymes of G. diazotrophicus strain PAL5 play an important role in the endophytic colonization of rice plants.


Subject(s)
Gene Expression Regulation, Enzymologic/physiology , Gluconacetobacter/enzymology , Glutathione Reductase/metabolism , Oryza/microbiology , Plant Roots/microbiology , Superoxide Dismutase/metabolism , Cloning, Molecular , Gene Deletion , Gene Expression Regulation, Bacterial/physiology , Gluconacetobacter/genetics , Gluconacetobacter/metabolism , Glutathione Reductase/genetics , In Situ Hybridization, Fluorescence , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reactive Oxygen Species , Real-Time Polymerase Chain Reaction , Superoxide Dismutase/genetics , Symbiosis , Time Factors
11.
Plants (Basel) ; 12(23)2023 Dec 01.
Article in English | MEDLINE | ID: mdl-38068686

ABSTRACT

The simultaneous analysis of the maximum number of chemical elements present in plant tissues provides more comprehensive information about their chemical constitution and increases the number of characteristics for the selection process in various plant breeding programs. The objective of this study was to analyze productivity, grain yield, and concentration of chemical elements in tissues of Coffea canephora clones to study phenotypic diversity and estimate genetic parameters for use in breeding. This experiment was carried out in Manaus, Amazonas, Brazil, in randomized blocks with four replications. The concentrations of elements in various organs were quantified using total reflection X-ray fluorescence (TXRF). Genetic parameters and genetic divergence were estimated, and genotypes were clustered using the UPGMA hierarchical method and non-metric multidimensional scaling analysis. The study allowed us to differentiate the performance of the clones in terms of the absorption of essential and non-essential chemical elements for plant development and to analyze the correlation of the characteristics in the selection process. TXRF efficiently characterizes the presence and concentration of multiple elements, aiding genotype discrimination for C. canephora improvement.

12.
Plants (Basel) ; 12(18)2023 Sep 08.
Article in English | MEDLINE | ID: mdl-37765372

ABSTRACT

As agricultural practices become more sustainable, adopting more sustainable practices will become even more relevant. Searching for alternatives to chemical compounds has been the focus of numerous studies, and bacteriocins are tools with intrinsic biotechnological potential for controlling plant diseases. We continued to explore the biotechnological activity of the bacteriocin Gluconacin from Gluconacetobacter diazotrophicus, PAL5 strain, by investigating this protein's antagonism against important tomato phytopathogens and demonstrating its effectiveness in reducing bacterial spots caused by Xanthomonas perforans. In addition to this pathogen, the bacteriocin Gluconacin demonstrated bactericidal activity in vitro against Ralstonia solanacearum and Pseudomonas syringae pv. tomato, agents that cause bacterial wilt and bacterial spots, respectively. Bacterial spot control tests showed that Gluconacin reduced disease severity by more than 66%, highlighting the biotechnological value of this peptide in ecologically correct formulations.

13.
Bol Asoc Med P R ; 104(3): 32-4, 2012.
Article in Spanish | MEDLINE | ID: mdl-23156889

ABSTRACT

Tumors of the orbit are pathology of considerable complexity in management due to the diverse anatomic and muscular, vascular, cartilagenous and neural components present. We review a series of 35 cases managed at the National Institute of Cancer in Bogota, Colombia. We determine variables such as age, sex, symptoms, histology, location and surgical procedure of these tumors. This review suggest that this complex pathology should be managed by a multidisciplinary team with extensive neurosurgical experience to obtain satisfactory results.


Subject(s)
Orbital Neoplasms/therapy , Adolescent , Adult , Aged , Child , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Young Adult
14.
Rev Chilena Infectol ; 39(2): 218-220, 2022 04.
Article in Spanish | MEDLINE | ID: mdl-35856997

ABSTRACT

There are few cases reports of Enterobacter cancerogenus infections. Although it has been isolated in contaminated wounds associated with trauma, it has also been reported as an etiological agent in a wide variety of other infections, with the presence of bacteremia being infrequent. We present the first case reported in Chile of a bacteremia caused by this agent, in a 28-year-old patient with a stable pelvic fracture due a high-energy traffic accident. He had a good clinical response to treatment with ertapenem.


Subject(s)
Bacteremia , Enterobacteriaceae Infections , Adult , Bacteremia/drug therapy , Chile , Enterobacter , Enterobacteriaceae Infections/drug therapy , Ertapenem , Humans , Male
15.
Plants (Basel) ; 11(21)2022 Nov 02.
Article in English | MEDLINE | ID: mdl-36365412

ABSTRACT

Astrocaryum aculeatum, a palm tree incipiently domesticated from upland ecosystems in the Brazilian Amazon, is especially adapted to anthropized areas. The pulp of the fruit, obtained by extractivism, is consumed fresh by the Amazonian population. The objective of the study is to evaluate the diversity and genetic structure of the natural populations of A. aculeatum, exploited by extractive farmers in Amazonas, Brazil, seeking to suggest conservation and management strategies for this species. A total of 218 plants were sampled in 15 populations in 14 municipalities in the state of Amazonas, evaluated by 12 microsatellite loci. A total of 101 alleles were observed. The means of the observed heterozygosities (HO = 0.6390) were higher than expected (HE = 0.557), with high levels of heterozygotes in the populations. The fixation index in the loci and populations was negative. The FST (0.07) and AMOVA showed moderate population structure. Bayesian analysis indicated the grouping k = 4 as the most adequate. There is a high genetic diversity in populations, with a moderate genetic structure due to possible historical events, which could be related to the process of subpopulation formation, possibly presenting three historical moments: before and after the beginning of deforestation and today. The conservation and management policies of this species must be carried out at a watershed level.

16.
Plants (Basel) ; 12(1)2022 Dec 22.
Article in English | MEDLINE | ID: mdl-36616175

ABSTRACT

Herbaspirillum seropedicae is an endophytic bacterium that can fix nitrogen and synthesize phytohormones, which can lead to a plant growth-promoting effect when used as a microbial inoculant. Studies focused on mechanisms of action are crucial for a better understanding of the bacteria-plant interaction and optimization of plant growth-promoting response. This work aims to understand the underlined mechanisms responsible for the early stimulatory growth effects of H. seropedicae inoculation in maize. To perform these studies, we combined transcriptomic and proteomic approaches with physiological analysis. The results obtained eight days after inoculation (d.a.i) showed increased root biomass (233 and 253%) and shoot biomass (249 and 264%), respectively, for the fresh and dry mass of maize-inoculated seedlings and increased green content and development. Omics data analysis, before a positive biostimulation phenotype (5 d.a.i.) revealed that inoculation increases N-uptake and N-assimilation machinery through differentially expressed nitrate transporters and amino acid pathways, as well carbon/nitrogen metabolism integration by the tricarboxylic acid cycle and the polyamine pathway. Additionally, phytohormone levels of root and shoot tissues increased in bacterium-inoculated-maize plants, leading to feedback regulation by the ubiquitin-proteasome system. The early biostimulatory effect of H. seropedicae partially results from hormonal modulation coupled with efficient nutrient uptake-assimilation and a boost in primary anabolic metabolism of carbon-nitrogen integrative pathways.

17.
Mol Plant Microbe Interact ; 24(12): 1448-58, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21809982

ABSTRACT

The genome of the endophytic diazotrophic bacterial species Gluconacetobacter diazotrophicus PAL5 (PAL5) revealed the presence of a gum gene cluster. In this study, the gumD gene homologue, which is predicted to be responsible for the first step in exopolysaccharide (EPS) production, was insertionally inactivated and the resultant mutant (MGD) was functionally studied. The mutant MGD presented normal growth and nitrogen (N(2)) fixation levels but did not produce EPS when grown on different carbon sources. MGD presented altered colony morphology on soft agar plates (0.3% agar) and was defective in biofilm formation on glass wool. Most interestingly, MGD was defective in rice root surface attachment and in root surface and endophytic colonization. Genetic complementation reverted all mutant phenotypes. Also, the addition of EPS purified from culture supernatants of the wild-type strain PAL5 to the mutant MGD was effective in partially restoring wild-type biofilm formation and plant colonization. These data provide strong evidence that the PAL5 gumD gene is involved in EPS biosynthesis and that EPS biosynthesis is required for biofilm formation and plant colonization. To our knowledge, this is the first report of a role of EPS in the endophytic colonization of graminaceous plants by a nitrogen-fixing bacterium.


Subject(s)
Biofilms/growth & development , Genes, Bacterial/genetics , Gluconacetobacter/metabolism , Oryza/microbiology , Polysaccharides, Bacterial/metabolism , Endophytes , Genetic Complementation Test , Genome, Bacterial/genetics , Gluconacetobacter/genetics , Gluconacetobacter/physiology , Green Fluorescent Proteins , Hydroponics , Multigene Family , Mutagenesis, Insertional , Nitrogen Fixation , Plant Roots/microbiology , Polysaccharides, Bacterial/isolation & purification , Seedlings/microbiology , Symbiosis
18.
Life (Basel) ; 11(11)2021 Nov 13.
Article in English | MEDLINE | ID: mdl-34833106

ABSTRACT

The biosynthesis of exopolysaccharides (EPSs) is essential for endophytic bacterial colonisation in plants bacause this exopolymer both protects bacterial cells against the defence and oxidative systems of plants and acts on the plant colonisation mechanism in Gluconacetobacter diazotrophicus. The pathway involved in the biosynthesis of bacterial EPS has not been fully elucidated, and several areas related to its molecular regulation mechanisms are still lacking. G. diazotrophicus relies heavily on EPS for survival indirectly by protecting plants from pathogen attack as well as for endophytic maintenance and adhesion in plant tissues. Here, we report that EPS from G. diazotrophicus strain Pal5 is a signal polymer that controls its own biosynthesis. EPS production depends on a bacterial tyrosine (BY) kinase (Wzc) that consists of a component that is able to phosphorylate a glycosyltranferase or to self-phosphorylate. EPS interacts with the extracellular domain of Wzc, which regulates kinase activity. In G. diazotrophicus strains that are deficient in EPS production, the Wzc is rendered inoperative by self-phosphorylation. The presence of EPS promotes the phosphorylation of a glycosyltransferase in the pathway, thus producing EPS. Wzc-mediated self-regulation is an attribute for the control of exopolysaccharide biosynthesis in G. diazotrophicus.

19.
J Med Eng Technol ; 45(5): 380-393, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33847217

ABSTRACT

Neck injuries and pathologies are widespread and cause disability. Clinicians use different tools to measure the cervical spine' mobility to diagnose different disorders. There are many reliable assessment methods for this purpose, but their benefits have not been deeply investigated and compared, as well as their measurement results. This review aims to summarise the advantages, accuracy, and reliability, of measurement tools and devices used in studies or trails related to the neck and cervical spine evaluation, to evidence the use of inertial sensors and compare them, to highlight the best assessment systems and their characteristics. A literature review has been performed in a range of five years, to obtain information about cervical spine evaluation. Studies that met the established inclusion criteria were selected and classified according their pathology studied, objectives and methodologies followed when evaluating the cervical spine functionality. Studies were described chronologically highlighting the tools employed, where the motion capture systems and cervical range of motion devices stood out as the most used and reliable methods. Cervical spine assessment studies employing systems with inertial sensors as an accurate method, is not evidenced in the sample. However, they are widely tested and different studies validate these systems for their clinical area use, obtaining high reliability and repeatability. Thereby, this review argues that inertial sensors have proven to be a portable, and easy to use tool for the evaluation of neck and its related pathologies, with a great accuracy level.


Subject(s)
Cervical Vertebrae , Humans , Range of Motion, Articular , Reproducibility of Results
20.
J Med Eng Technol ; 45(7): 532-545, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34060967

ABSTRACT

Nowadays, there are several diseases which affect different systems of the body, producing changes in the correct functioning of the organism and the people lifestyles. One of them is Parkinson's disease (PD), which is defined as a neurodegenerative disorder provoked by the destruction of dopaminergic neurons in the brain, resulting in a set of motor and non-motor symptoms. As this disease affects principally to ancient people, several researchers have studied different treatments and therapies for stopping neurodegeneration and diminishing symptoms, to improve the quality patients' lives. The most common therapies created for PD are based on pharmacological treatment for controlling the degeneration advance and the physical ones which do not reveal the progress of patients. For this reason, this review paper opens the possibility for using wearable motion capture systems as an option for the control and study of PD. Therefore, it aims to (1) study the different wearable systems used for capture the movements of PD patients and (2) determine which of them bring better results for monitoring and assess PD people. For the analysis, it uses papers based on experiments that prove the functioning of several motion systems in different aspects as monitoring, treatment and diagnose of the disease. As a result, it works with 30 papers which describe the factors mentioned before. Additionally, the paper uses journals and literature review about the pathology, its characteristics and the function of wearable sensors for the correct understanding of the topic.


Subject(s)
Parkinson Disease , Wearable Electronic Devices , Brain , Humans , Motion , Movement , Parkinson Disease/diagnosis
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