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1.
Proc Natl Acad Sci U S A ; 120(23): e2221244120, 2023 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-37252999

RESUMO

Missense variant Ile79Asn in human cardiac troponin T (cTnT-I79N) has been associated with hypertrophic cardiomyopathy and sudden cardiac arrest in juveniles. cTnT-I79N is located in the cTnT N-terminal (TnT1) loop region and is known for its pathological and prognostic relevance. A recent structural study revealed that I79 is part of a hydrophobic interface between the TnT1 loop and actin, which stabilizes the relaxed (OFF) state of the cardiac thin filament. Given the importance of understanding the role of TnT1 loop region in Ca2+ regulation of the cardiac thin filament along with the underlying mechanisms of cTnT-I79N-linked pathogenesis, we investigated the effects of cTnT-I79N on cardiac myofilament function. Transgenic I79N (Tg-I79N) muscle bundles displayed increased myofilament Ca2+ sensitivity, smaller myofilament lattice spacing, and slower crossbridge kinetics. These findings can be attributed to destabilization of the cardiac thin filament's relaxed state resulting in an increased number of crossbridges during Ca2+ activation. Additionally, in the low Ca2+-relaxed state (pCa8), we showed that more myosin heads are in the disordered-relaxed state (DRX) that are more likely to interact with actin in cTnT-I79N muscle bundles. Dysregulation of the myosin super-relaxed state (SRX) and the SRX/DRX equilibrium in cTnT-I79N muscle bundles likely result in increased mobility of myosin heads at pCa8, enhanced actomyosin interactions as evidenced by increased active force at low Ca2+, and increased sinusoidal stiffness. These findings point to a mechanism whereby cTnT-I79N weakens the interaction of the TnT1 loop with the actin filament, which in turn destabilizes the relaxed state of the cardiac thin filament.


Assuntos
Miofibrilas , Troponina T , Humanos , Miofibrilas/genética , Miofibrilas/patologia , Troponina T/genética , Troponina T/química , Actinas/genética , Mutação , Citoesqueleto de Actina/genética , Miosinas , Cálcio
2.
Plant J ; 119(1): 557-576, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38627952

RESUMO

Medicago truncatula is a model legume for fundamental research on legume biology and symbiotic nitrogen fixation. Tnt1, a retrotransposon from tobacco, was used to generate insertion mutants in M. truncatula R108. Approximately 21 000 insertion lines have been generated and publicly available. Tnt1 retro-transposition event occurs during somatic embryogenesis (SE), a pivotal process that triggers massive methylation changes. We studied the SE of M. truncatula R108 using leaf explants and explored the dynamic shifts in the methylation landscape from leaf explants to callus formation and finally embryogenesis. Higher cytosine methylation in all three contexts of CG, CHG, and CHH patterns was observed during SE compared to the controls. Higher methylation patterns were observed in assumed promoter regions (~2-kb upstream regions of transcription start site) of the genes, while lowest was recorded in the untranslated regions. Differentially methylated promoter region analysis showed a higher CHH methylation in embryogenesis tissue samples when compared to CG and CHG methylation. Strong correlation (89.71%) was identified between the differentially methylated regions (DMRs) and the site of Tnt1 insertions in M. truncatula R108 and stronger hypermethylation of genes correlated with higher number of Tnt1 insertions in all contexts of CG, CHG, and CHH methylation. Gene ontology enrichment and KEGG pathway enrichment analysis identified genes and pathways enriched in the signal peptide processing, ATP hydrolysis, RNA polymerase activity, transport, secondary metabolites, and nitrogen metabolism pathways. Combined gene expression analysis and methylation profiling showed an inverse relationship between methylation in the DMRs (regions spanning genes) and the expression of genes. Our results show that a dynamic shift in methylation happens during the SE process in the context of CG, CHH and CHG methylation, and the Tnt1 retrotransposition correlates with the hyperactive methylation regions.


Assuntos
Metilação de DNA , Regulação da Expressão Gênica de Plantas , Medicago truncatula , Técnicas de Embriogênese Somática de Plantas , Retroelementos , Medicago truncatula/genética , Medicago truncatula/metabolismo , Retroelementos/genética , Genoma de Planta/genética , Regiões Promotoras Genéticas/genética
3.
Plant Biotechnol J ; 22(9): 2530-2540, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38690830

RESUMO

Dinitrotoluene sulfonates (DNTSes) are highly toxic hazards regulated by the Resource Conservation and Recovery Act (RCRA) in the United States. The trinitrotoluene (TNT) red water formed during the TNT purification process consists mainly of DNTSes. Certain plants, including switchgrass, reed and alfalfa, can detoxify low concentrations of DNTS in TNT red water-contaminated soils. However, the precise mechanism by which these plants detoxify DNTS remains unknown. In order to aid in the development of phytoremediation resources with high DNTS removal rates, we identified and characterized 1-hydroxymethyl-2,4-dinitrobenzene sulfonic acid (HMDNBS) and its glycosylated product HMDNBS O-glucoside as the degradation products of 2,4-DNT-3-SO3Na, the major isoform of DNTS in TNT red water-contaminated soils, in switchgrass via LC-MS/MS- and NMR-based metabolite analyses. Transcriptomic analysis revealed that 15 UDP-glycosyltransferase genes were dramatically upregulated in switchgrass plants following 2,4-DNT-3-SO3Na treatment. We expressed, purified and assayed the activity of recombinant UGT proteins in vitro and identified PvUGT96C10 as the enzyme responsible for the glycosylation of HMDNBS in switchgrass. Overexpression of PvUGT96C10 in switchgrass significantly alleviated 2,4-DNT-3-SO3Na-induced plant growth inhibition. Notably, PvUGT96C10-overexpressing transgenic switchgrass plants removed 83.1% of 2,4-DNT-3-SO3Na in liquid medium after 28 days, representing a 3.2-fold higher removal rate than that of control plants. This work clarifies the DNTS detoxification mechanism in plants for the first time, suggesting that PvUGT96C10 is crucial for DNTS degradation. Our results indicate that PvUGT96C10-overexpressing plants may hold great potential for the phytoremediation of TNT red water-contaminated soils.


Assuntos
Biodegradação Ambiental , Glicosiltransferases , Panicum , Panicum/genética , Panicum/metabolismo , Panicum/enzimologia , Glicosiltransferases/metabolismo , Glicosiltransferases/genética , Dinitrobenzenos/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Regulação da Expressão Gênica de Plantas , Poluentes do Solo/metabolismo
4.
Plant Cell Environ ; 47(8): 3076-3089, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38679945

RESUMO

Flavonoids are usually present in forms of glucosides in plants, which could be catabolized by ß-glucosidase (BGLU) to form their corresponding flavonoid aglycones. In this study, we isolated three abiotic-responsive BGLU genes (MtBGLU17, MtBGLU21 and MtBGLU22) from Medicago truncatula, and found only the recombinant MtBGLU17 protein could catalyse the hydrolysis of flavonoid glycosides. The recombinant MtBGLU17 protein is active towards a variety of flavonoid glucosides, including glucosides of flavones (apigenin and luteolin), flavonols (kaempferol and quercetin), isoflavones (genistein and daidzein) and flavanone (naringenin). In particular, the recombinant MtBGLU17 protein preferentially hydrolyses flavonoid-7-O-glucosides over their corresponding 3-O-glucosides. The content of luteoin-7-O-glucoside was reduced in the MtBGLU17 overexpression plants but increased in the Tnt-1 insertional mutant lines, whereas luteoin content was increased in the MtBGLU17 overexpression plants but reduced in the Tnt-1 insertional mutant lines. Under drought and salt (NaCl) treatment, the MtBGLU17 overexpression lines showed relatively higher DPPH content, and higher CAT and SOD activity than the wild type control. These results indicated that overexpression lines of MtBGLU17 possess higher antioxidant activity and thus confer drought and salt tolerance, implying MtBGLU17 could be potentially used as a candidate gene to improve plant abiotic stress tolerance.


Assuntos
Antioxidantes , Secas , Flavonoides , Medicago truncatula , Proteínas de Plantas , Tolerância ao Sal , beta-Glucosidase , Medicago truncatula/genética , Medicago truncatula/enzimologia , Medicago truncatula/metabolismo , Medicago truncatula/fisiologia , Flavonoides/metabolismo , Antioxidantes/metabolismo , beta-Glucosidase/metabolismo , beta-Glucosidase/genética , Tolerância ao Sal/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Regulação da Expressão Gênica de Plantas
5.
Environ Res ; 252(Pt 1): 118820, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38555093

RESUMO

As a typical energetic compound widely used in military activities, 2,4,6-trinitrotoluene (TNT) has attracted great attention in recent years due to its heavy pollution and wide distribution in and around the training facilities, firing ranges, and demolition sites. However, the subcellular targets and the underlying toxic mechanism of TNT remain largely unknown. In this study, we explored the toxic effects of TNT biological reduction on the mitochondrial function and homeostasis in Caenorhabditis elegans (C. elegans). With short-term exposure of L4 larvae, 10-1000 ng/mL TNT reduced mitochondrial membrane potential and adenosine triphosphate (ATP) content, which was associated with decreased expression of specific mitochondrial complex involving gas-1 and mev-1 genes. Using fluorescence-labeled transgenic nematodes, we found that fluorescence expression of sod-3 (muls84) and gst-4 (dvls19) was increased, suggesting that TNT disrupted the mitochondrial antioxidant defense system. Furthermore, 10 ng/mL TNT exposure increased the expression of the autophagy-related gene pink-1 and activated mitochondrial unfolded protein response (mt UPR), which was indicated by the increased expression of mitochondrial stress activated transcription factor atfs-1, ubiquitin-like protein ubl-5, and homeobox protein dve-1. Our findings demonstrated that TNT biological reduction caused mitochondrial dysfunction and the development of mt UPR protective stress responses, and provided a basis for determining the potential risks of energetic compounds to living organisms.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Mitocôndrias , Trinitrotolueno , Animais , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Trinitrotolueno/toxicidade , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Transporte de Elétrons/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo
6.
Arch Toxicol ; 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39158710

RESUMO

Seas worldwide are threatened by an emerging source of pollution as millions of tons of warfare materials were dumped after the World Wars. As their metal shells are progressively corroding, energetic compounds (EC) leak out and distribute in the marine environment. EC are taken up by aquatic organisms and pose a threat to both the marine ecosphere and the human seafood consumer because of their toxicity and potential carcinogenicity. Here, sediment samples and fish from different locations in the German North Sea of Lower Saxony were examined to determine whether EC transfer to fish living close to munition dumping areas. EC were found in sediments with a maximum concentration of 1.5 ng/kg. All analyzed fish muscle tissues/fillets and bile samples were positive for EC detection. In bile, the max. EC concentrations ranged between 0.25 and 1.25 ng/mL. Interestingly, while detected TNT metabolites in the muscle tissues were in concentrations of max. 1 ng/g (dry weight), TNT itself was found in concentrations of up to 4 ng/g (dry weight). As we found considerable higher amounts of non-metabolized TNT in the fish muscle, rather than TNT metabolites, we conclude an additional absorption route of EC into fish other than per diet. This is the first study to detect EC in the edible parts of fish caught randomly in the North Sea.

7.
Memory ; : 1-11, 2024 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-39383331

RESUMO

The Think/No-Think (TNT) task examines the effects of attempts at suppressing particular stimuli. First, participants learn cue-target word pairs. Subsequently, they either recall (Think trials) or avoid thinking about targets whatsoever (No-Think trials) in response to cues. The critical finding is that No-Think targets are recalled less well than Baseline items (i.e., Suppression-Induced Forgetting; SIF). Wiechert et al.'s [(2023). Suppression-induced forgetting: A pre-registered replication of the think/no-think paradigm. Memory (Hove, England), 31(7), 989-1002] null-findings in Prolific workers using online video calls casted doubts on the robustness of the effect. We adapted their procedure in two replication studies testing undergraduate psychology students. The first study (N = 54) adapted Wiechert's procedure to an in-person laboratory setting using Same Probe (SP) recall and found evidence for SIF. Hypothesizing that an online test should yield SIF in undergraduates as well, study 2 replicated both the in-person laboratory (n = 54) and online (n = 54) procedures. The results suggested evidence for SIF in the in-lab setting, yet no evidence was observed in the online setting. As exploratory Bayesian analyses showed conclusive evidence for a null effect, this pattern of results does not imply that the in-lab and online settings actually differed. Yet, overall, the results cast doubts on the generalisability of the SIF-effect .

8.
Int J Mol Sci ; 25(17)2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39273448

RESUMO

In view of the current problems of slow crystallization rate, varying grain sizes, complex process conditions, and low safety in the preparation of CL-20/TNT cocrystal explosives in the laboratory, an opposite spray crystallization method is provided to quickly prepare ultrafine explosive cocrystal particles. CL-20/TNT cocrystal explosive was prepared using this method, and the obtained cocrystal samples were characterized by electron microscopy morphology, differential thermal analysis, infrared spectroscopy, and X-ray diffraction analysis. The effects of spray temperature, feed ratio, and preparation method on the formation of explosive cocrystal were studied, and the process conditions of the pneumatic atomization spray crystallization method were optimized. The crystal plane binding energy and molecular interaction forces between CL-20 and TNT were obtained through molecular dynamic simulation, and the optimal binding crystal plane and cocrystal mechanism were analyzed. The theoretical calculation temperature of the binding energy was preliminarily explored in relation to the preparation process temperature of cocrystal explosives. The mechanical sensitivity of ultrafine CL-20/TNT cocrystal samples was tested. The results showed that choosing acetone as the cosolvent, a spraying temperature of 30 °C, and a feeding ratio of 1:1 was beneficial for the formation and growth of cocrystal. The prepared CL-20/TNT cocrystal has a particle size of approximately 10 µm. The grain size is small, and the crystallization rate is fast. The impact and friction sensitivity of ultrafine CL-20/TNT cocrystal samples were significantly reduced. The experimental process conditions are simple and easy to control, and the safety of the preparation process is high, providing certain technical support for the preparation of high-quality cocrystal explosives.


Assuntos
Cristalização , Substâncias Explosivas , Simulação de Dinâmica Molecular , Trinitrotolueno , Cristalização/métodos , Substâncias Explosivas/química , Trinitrotolueno/química , Difração de Raios X , Temperatura
9.
Molecules ; 29(5)2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38474612

RESUMO

Layers of TiO2 nanotubes formed by the anodization process represent an area of active research in the context of innovative energy conversion and storage systems. Titanium nanotubes (TNTs) have attracted attention because of their unique properties, especially their high surface-to-volume ratio, which makes them a desirable material for various technological applications. The anodization method is widely used to produce TNTs because of its simplicity and relative cheapness; the method enables precise control over the thickness of TiO2 nanotubes. Anodization can also be used to create decorative and colored coatings on titanium nanotubes. In this study, a combined structure including anodic TiO2 nanotubes and SrTiO3 particles was fabricated using chemical synthesis techniques. TiO2 nanotubes were prepared by anodizing them in ethylene glycol containing NH4F and H2O while applying a voltage of 30 volts. An anode nanotube array heat-treated at 450 °C was then placed in an autoclave filled with dilute SrTiO3 solution. Scanning electron microscopy (SEM) analysis showed that the TNTs were characterized by clear and open tube ends, with an average outer diameter of 1.01 µm and an inner diameter of 69 nm, and their length is 133 nm. The results confirm the successful formation of a structure that can be potentially applied in a variety of applications, including hydrogen production by the photocatalytic decomposition of water under sunlight.

10.
Molecules ; 29(11)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38893427

RESUMO

An external electric field is an effective tool to induce the polymorphic transformation of molecular crystals, which is important practically in the chemical, material, and energy storage industries. However, the understanding of this mechanism is poor at the molecular level. In this work, two types of order parameters (OPs) were constructed for the molecular crystal based on the intermolecular distance, bond orientation, and molecular orientation. Using the K-means clustering algorithm for the sampling of OPs based on the Euclidean distance and density weight, the polymorphic transformation of TNT was investigated using a finite temperature string (FTS) under external electric fields. The potential of mean force (PMF) was obtained, and the essence of the polymorphic transformation between o-TNT and m-TNT was revealed, which verified the effectiveness of the FTS method based on K-means clustering to OPs. The differences in PMFs between the o-TNT and transition state were decreased under external electric fields in comparison with those in no field. The fields parallel to the c-axis obviously affected the difference in PMF, and the relationship between the changes in PMFs and field strengths was found. Although the external electric field did not promote the convergence, the time of the polymorphic transformation was reduced under the external electric field in comparison to its absence. Moreover, under the external electric field, the polymorphic transformation from o-TNT to m-TNT occurred while that from m-TNT to o-TNT was prevented, which was explained by the dipole moment of molecule, relative permittivity, chemical potential difference, nucleation work and nucleation rate. This confirmed that the polymorphic transformation orientation of the molecular crystal could be controlled by the external electric field. This work provides an effective way to explore the polymorphic transformation of the molecular crystals at a molecular level, and it is useful to control the production process and improve the performance of energetic materials by using the external electric fields.

11.
Plant J ; 111(2): 608-616, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35510429

RESUMO

Though Medicago truncatula Tnt1 mutants are widely used by researchers in the legume community, they are mainly used for reverse genetics because of the availability of the BLAST-searchable large-scale flanking sequence tags database. However, these mutants should have also been used extensively for forward genetic screens, an effort that has been hindered due to the lack of a compatible genetic crossing partner for the M. truncatula genotype R108, from which Tnt1 mutants were generated. In this study, we selected three Medicago HapMap lines (HM017, HM018 and HM022) and performed reciprocal genetic crosses with R108. After phenotypic analyses in F1 and F2 progenies, HM017 was identified as a compatible crossing partner with R108. By comparing the assembled genomic sequences of HM017 and R108, we developed and confirmed 318 Indel markers evenly distributed across the eight chromosomes of the M. truncatula genome. To validate the effectiveness of these markers, by employing the map-based cloning approach, we cloned the causative gene in the dwarf mutant crs isolated from the Tnt1 mutant population, identifying it as gibberellin 3-ß-dioxygenase 1, using some of the confirmed Indel markers. The primer sequences and the size difference of each marker were made available for users in the web-based database. The identification of the crossing partner for R108 and the generation of Indel markers will enhance the forward genetics and the overall usage of the Tnt1 mutants.


Assuntos
Medicago truncatula , Bases de Dados de Ácidos Nucleicos , Genes de Plantas , Testes Genéticos , Medicago truncatula/genética , Mutagênese Insercional
12.
Histochem Cell Biol ; 159(1): 47-60, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36175690

RESUMO

The cytoskeleton not only deals with numerous interaction and communication mechanisms at the cellular level but also has a crucial role in the viral infection cycle. Although numerous aspects of SARS-CoV-2 virus interaction at the cellular level have been widely studied, little has been reported about the structural and functional response of the cytoskeleton. This work aims to characterize, at the ultrastructural level, the modifications in the cytoskeleton of infected cells, namely, its participation in filopodia formation, the junction of these nanostructures forming bridges, the viral surfing, and the generation of tunnel effect nanotubes (TNT) as probable structures of intracellular viral dissemination. The three-dimensional reconstruction from the obtained micrographs allowed observing viral propagation events between cells in detail for the first time. More profound knowledge about these cell-cell interaction models in the viral spread mechanisms could lead to a better understanding of the clinical manifestations of COVID-19 disease and to find new therapeutic strategies.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Imageamento Tridimensional , Citoesqueleto , Comunicação Celular
13.
Arch Microbiol ; 206(1): 39, 2023 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-38142428

RESUMO

Two motile, rod-shaped, Gram-stain-negative bacterial strains, TNT11T and TNT19T, were isolated from soil samples collected at Deception Island, Antarctica. According to the 16S rRNA gene sequence similarity, both strains belong to the genus Pseudomonas. Further genomic analyses based on ANI and dDDH suggested that these strains were new species. Growth of strain TNT11T is observed at 0-30 â„ƒ (optimum, 20 â„ƒ), pH 4.0-9.0 (optimum, pH 6.0) and in the presence of 0-5.0% NaCl (optimum, 1% NaCl), while for TNT19T is observed at 0-30 â„ƒ (optimum between 15 and 20 â„ƒ), pH 5.0-9.0 (optimum, pH 6.0) and in the presence of 0-5.0% NaCl (optimum between 0 and 1% NaCl). The fatty acid profile consists of the major compounds; C16:0 and C16:1 ω6 for TNT11T, and C16:0 and C12:0 for TNT19T. Based on the draft genome sequences, the DNA G + C content for TNT11T is 60.43 mol% and 58.60 mol% for TNT19T. Based on this polyphasic study, TNT11T and TNT19T represent two novel species of the genus Pseudomonas, for which the proposed names are Pseudomonas violetae sp. nov. and Pseudomonas emilianonis sp. nov., respectively. The type strains are Pseudomonas violetae TNT11T (= RGM 3443T = LMG 32959T) and Pseudomonas emilianonis TNT19T (= RGM 3442T = LMG 32960T). Strains TNT11T and TNT19T were deposited to CChRGM and BCCM/LMG with entry numbers RGM 3443/LMG 32959 and RGM 3442/LMG 32960, respectively.


Assuntos
Fosfolipídeos , Pseudomonas , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Regiões Antárticas , Pseudomonas/genética , Cloreto de Sódio , DNA Bacteriano/genética , Análise de Sequência de DNA , Hibridização de Ácido Nucleico , Filogenia , Técnicas de Tipagem Bacteriana , Ácidos Graxos/química , Enganação , Solo
14.
Environ Sci Technol ; 57(48): 20169-20181, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-37933956

RESUMO

Submerged munitions from World War I and II are threatening human activities in the oceans, including fisheries and shipping or the construction of pipelines and offshore facilities. To avoid unforeseen explosions, remotely controlled "blast-in-place" (BiP) operations are a common practice worldwide. However, after underwater BiP detonations, the toxic and carcinogenic energetic compounds (ECs) will not completely combust but rather distribute within the marine ecosphere. To shed light on this question, two comparable World War II mines in Denmark's Sejerø Bay (Baltic Sea) were blown up by either low-order or high-order BiP operations by the Royal Danish Navy. Water and sediment samples were taken before and immediately after the respective BiP operation and analyzed for the presence of ECs with sensitive GC-MS/MS and LC-MS/MS technology. EC concentrations increased after high-order BiP detonations up to 353 ng/L and 175 µg/kg in water and sediment, respectively, while low-order BiP detonations resulted in EC water and sediment concentrations up to 1,000,000 ng/L (1 mg/L) and >10,000,000 µg/kg (>10 g/kg), respectively. Our studies provide unequivocal evidence that BiP operations in general lead to a significant increase of contamination of the marine environment and ecotoxicological risk with toxic ECs. Moreover, as compared to high-order BiP detonations, low-order BiP detonations resulted in a several 1000-fold higher burden on the marine environment.


Assuntos
Explosões , Poluentes Químicos da Água , Humanos , Espectrometria de Massas em Tandem , Cromatografia Líquida , Oceanos e Mares , Água , Poluentes Químicos da Água/toxicidade
15.
Int J Audiol ; 62(1): 21-29, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35015970

RESUMO

OBJECTIVE: This study used the multi-level Tracking of Noise Tolerance (TNT) test to compare Augmented Focus (AF) or split processing over non-AF processing with adaptive directionality (non-AF-dirm) and with an omnidirectional microphone (non-AF-omni). DESIGN: This was a single-blind, within-subject repeated measures design. STUDY SAMPLE: Nineteen listeners with a mild-to-moderate hearing loss. The listeners' task was to determine their tolerable noise level (TNL) in the sound-field at four fixed speech levels (i.e. 62, 68, 75, and 85 dB SPL) in the unaided condition and the different aided conditions. The speech passages were presented from 0° while a continuous speech-shaped noise was presented from 180°. Each condition was tested twice, each in a different counterbalanced order. RESULTS: AF improved TNL by an average of 2.9 dB over non-AF-dirm. Adaptive directionality improved the aided TNL by 4.7 dB over the non-AF-omni condition. The unaided TNL was similar to the aided non-AF-omni TNL. Whereas a stable TNL was reached in 20-30 s for non-AF-dirm, it took AF < 15 s to reach a stable TNL at all input levels. CONCLUSIONS: This study shows that AF allowed 2.9 dB of signal-to-noise ratio (SNR) improvement over that of non-AF-dirm and 7.6 dB over the aided non-AF-omni condition.


Assuntos
Auxiliares de Audição , Perda Auditiva Neurossensorial , Percepção da Fala , Humanos , Método Simples-Cego , Ruído/efeitos adversos
16.
Int J Audiol ; : 1-8, 2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37335169

RESUMO

OBJECTIVE: To gather preliminary reference data on older normal-hearing (NH) adults for the refined Tracking of Noise Tolerance (TNT) test. DESIGN: Within-subject repeated measures. Participants were tested on the TNT in the sound-field and under headphones. In the sound-field, speech stimuli were presented at 75 dB SPL and 82 dB SPL from 0° with a speech-shaped noise presented either from 0° or 180° at a level controlled by the participants. The order of signal level, mode of presentation, noise azimuth, and TNT passages were counterbalanced across listeners. Testing was repeated for one condition after 1-3 weeks to estimate within-session and between-session reliability. STUDY SAMPLE: Twenty-five NH listeners (51-82 yrs of age). RESULTS: Mean TNT scores (TNTAve) were about 4 dB at a speech input of 75 dB SPL and 3 dB at 82 dB SPL. The TNTAve was similar between the headphone and sound-field presentations in the co-located noise. TNTAve scores measured with noise-back were about 1 dB better than those measured from the front. The 95% confidence intervals of absolute test-retest differences were about 1.2 dB within-session and 2.0 dB between sessions. CONCLUSIONS: The refined TNT may be a reliable tool to measure noise acceptance and subjective speech intelligibility.

17.
Molecules ; 28(4)2023 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-36838956

RESUMO

2,4,6-Trinitrotoluene (TNT) is an aromatic pollutant that is difficult to be degraded in the natural environment. The screening of efficient degrading bacteria for bioremediation of TNT has received much attention from scholars. In this paper, transcriptome analysis of the efficient degrading bacterium Buttiauxella sp. S19-1 revealed that the monooxygenase gene (BuMO) was significantly up-regulated during TNT degradation. S-ΔMO (absence of BuMO gene in S19-1 mutant) degraded TNT 1.66-fold less efficiently than strain S19-1 (from 71.2% to 42.9%), and E-MO mutant (Escherichia coli BuMO-expressing strain) increased the efficiency of TNT degradation 1.33-fold (from 52.1% to 69.5%) for 9 h at 180 rpm at 27 °C in LB medium with 1.4 µg·mL-1 TNT. We predicted the structure of BuMO and purified recombinant BuMO (rBuMO). Its specific activity was 1.81 µmol·min-1·mg-1 protein at pH 7.5 and 35 °C. The results of gas chromatography mass spectrometry (GC-MS) analysis indicated that 4-amino-2,6-dinitrotoluene (ADNT) is a metabolite of TNT biodegradation. We speculate that MO is involved in catalysis in the bacterial degradation pathway of TNT in TNT-polluted environment.


Assuntos
Trinitrotolueno , Biodegradação Ambiental , Trinitrotolueno/metabolismo , Oxigenases de Função Mista , Escherichia coli/metabolismo
18.
Medicina (Kaunas) ; 59(11)2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-38004042

RESUMO

Background and Objectives. Hospital-acquired pneumonia is one of the complications that may occur in the postoperative period in patients undergoing heart valve surgery, which may result in prolonged hospitalization, development of respiratory failure requiring mechanical ventilation or even death. This study investigated the preoperative risk factors of postoperative pneumonia after heart valve surgery. Materials and Methods: This was a prospective study in a group of consecutive patients with hemodynamically significant valvular heart disease undergoing valve surgery. The primary endpoint at the in-hospital follow-up was hospital-acquired pneumonia after heart valve surgery. Logistic regression analysis was used to assess which variables were predictive of the primary endpoint, and odds ratios (ORdis) were calculated with a 95% confidence interval (CI). Multivariate analysis was based on the results of single-factor logistic regression, i.e., in further steps all statistically significant variables were taken into consideration. Results: The present study included 505 patients. Postoperative pneumonia occurred in 23 patients. The mean time to diagnosis of pneumonia was approximately 3 days after heart valve surgery (±2 days). In multivariate analysis, preoperative level of high-sensitivity Troponin T (hs-TnT) (OR 2.086; 95% CI 1.211-3.593; p = 0.008) and right ventricular systolic pressure (RVSP) (OR 1.043; 95% CI 1.018-1.067; p 0.004) remained independent predictors of the postoperative pneumonia. Of the patients with postoperative pneumonia, 3 patients died due to the development of multiple organ dysfunction syndrome (MODS). Conclusions: Preoperative determination of serum hs-TnT concentration and echocardiographic measurement of the RVSP parameter may be useful in predicting postoperative pneumonia in patients undergoing heart valve surgery.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Complicações Pós-Operatórias , Humanos , Estudos Prospectivos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Fatores de Risco , Período Pós-Operatório
19.
Plant J ; 105(3): 816-830, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33176041

RESUMO

Legumes have unique features, such as compound inflorescences and a complex floral ontogeny. Thus, the study of regulatory genes in these species during inflorescence and floral development is essential to understand their role in the evolutionary origin of developmental novelties. The SUPERMAN (SUP) gene encodes a C2H2 zinc-finger transcriptional repressor that regulates the floral organ number in the third and fourth floral whorls of Arabidopsis thaliana. In this work, we present the functional characterization of the Medicago truncatula SUPERMAN (MtSUP) gene based on gene expression analysis, complementation and overexpression assays, and reverse genetic approaches. Our findings provide evidence that MtSUP is the orthologous gene of SUP in M. truncatula. We have unveiled novel functions for a SUP-like gene in eudicots. MtSUP controls not only the number of floral organs in the inner two whorls, but also in the second whorl of the flower. Furthermore, MtSUP regulates the activity of the secondary inflorescence meristem, thus controlling the number of flowers produced. Our work provides insight into the regulatory network behind the compound inflorescence and flower development in this angiosperm family.


Assuntos
Flores/crescimento & desenvolvimento , Medicago truncatula/crescimento & desenvolvimento , Proteínas de Plantas/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Flores/genética , Frutas/genética , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Teste de Complementação Genética , Inflorescência/genética , Inflorescência/crescimento & desenvolvimento , Medicago truncatula/genética , Mutação , Filogenia , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Fatores de Transcrição/genética
20.
Am J Kidney Dis ; 80(4): 483-494.e1, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35288215

RESUMO

RATIONALE & OBJECTIVE: Heart-type fatty acid binding protein (H-FABP) is a biomarker that has been shown to provide long-term prognostic information in patients with coronary artery disease independently of high-sensitivity troponin T (hs-TNT). We examined the independent associations of H-FABP with cardiovascular outcomes in patients with chronic kidney disease (CKD). STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 4,951 patients enrolled in the German Chronic Kidney Disease (GCKD) study with an estimated glomerular filtration rate of 30-60 mL/min/1.73 m2 or overt proteinuria (urinary albumin-creatinine ratio > 300 mg/g or equivalent). EXPOSURE: Serum levels of H-FABP and hs-TNT were measured at study entry. OUTCOME: Noncardiovascular (non-CV) death, CV death, combined major adverse CV events (MACE), and hospitalization for congestive heart failure (CHF). ANALYTICAL APPROACH: Hazard ratios (HRs) for associations of H-FABP and hs-TNT with outcomes were estimated using Cox regression analyses adjusted for established risk factors. RESULTS: During a maximum follow-up of 6.5 years, 579 non-CV deaths, 190 CV deaths, 522 MACE, and 381 CHF hospitalizations were observed. In Cox regression analyses adjusted for established risk factors, H-FABP was associated with all 4 outcomes, albeit with lower HRs than those found for hs-TNT. After further adjustment for hs-TNT levels, H-FABP was found to be associated with non-CV death (HR, 1.57 [95% CI, 1.14-2.18]) and MACE (HR, 1.40 [95% CI, 1.02-1.92]) but with neither CV death (HR, 1.64 [95% CI, 0.90-2.99]) nor CHF hospitalizations (HR, 1.02 [95% CI, 0.70-1.49]). LIMITATIONS: Single-point measurements of H-FABP and hs-TNT. Uncertain generalizability to non-European populations. CONCLUSIONS: In this large cohort of patients with CKD, H-FABP was associated with non-CV death and MACE, even after adjustment for hs-TNT. Whether measurement of H-FABP improves cardiovascular disease risk prediction in these patients warrants further studies.


Assuntos
Doenças Cardiovasculares , Insuficiência Cardíaca , Insuficiência Renal Crônica , Albuminas , Biomarcadores , Doenças Cardiovasculares/epidemiologia , Estudos de Coortes , Creatinina , Proteína 3 Ligante de Ácido Graxo , Insuficiência Cardíaca/epidemiologia , Humanos , Prognóstico , Estudos Prospectivos , Insuficiência Renal Crônica/epidemiologia , Troponina T
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