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1.
Planta ; 259(3): 65, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38329545

RESUMO

MAIN CONCLUSION: This study reveals that TRM21 acts as a positive regulator of flavonoid biosynthesis at the translational level in Arabidopsis, impacting both secondary metabolites and genes associated with root hair growth. TRM (TONNEAU1-recruiting motif) superfamily proteins are reported to be involved in microtubule assembly. However, the functions of this protein family are just beginning to be uncovered. Here, we provide metabolomic and genetic evidence that 1 of the 34 TRM members, TRM21, positively regulates the biosynthesis of flavonoids at the translational level in Arabidopsis thaliana. A loss-of-function mutation in TRM21 led to root hair growth defects and stunted plant growth, accompanied by significant alterations in secondary metabolites, particularly a marked reduction in flavonoid content. Interestingly, our study revealed that the transcription levels of genes involved in the flavonoid biosynthesis pathway remained unchanged in the trm21 mutants, but there was a significant downregulation in the translation levels of certain genes [flavanone 3-hydroxylase (F3H), dihydroflavonol-4-reductase (DFR), anthocyanidin reductase (ANR), flavanone 3'-hydroxylase (F3'H), flavonol synthase (FLS), chalcone synthase (CHS)]. Additionally, the translation levels of some genes related to root hair growth [RHO-related GTPases of plant 2 (ROP2), root hair defective 6 (RHD6), root hair defective 2 (RHD2)] were also reduced in the trm21 mutants. Taken together, these results indicate that TRM21 functions as a positive regulator of flavonoid biosynthesis at the translational level in Arabidopsis.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Flavonoides , Proteínas Associadas aos Microtúbulos , Antocianinas , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Regulação para Baixo , Flavonoides/biossíntese , Redes e Vias Metabólicas , Proteínas Associadas aos Microtúbulos/genética
2.
Angew Chem Int Ed Engl ; 63(16): e202400011, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38409577

RESUMO

Light-driven hydrogen production from biomass derivatives offers a path towards carbon neutrality. It is often however operated with the limitations of sluggish kinetics and severe coking. Herein, a disruptive air-promoted strategy is explored for efficient and durable light-driven hydrogen production from ethanol over a core/shell Cr2O3@GaN nanoarchitecture. The correlative computational and experimental investigations show ethanol is energetically favorable to be adsorbed on the Cr2O3@GaN interface, followed by dehydrogenation toward acetaldehyde and protons by photoexcited holes. The released protons are then consumed for H2 evolution by photogenerated electrons. Afterward, O2 can be evolved into active oxygen species and promote the deprotonation and C-C cleavage of the key C2 intermediate, thus significantly lowering the reaction energy barrier of hydrogen evolution and removing the carbon residual with inhibited overoxidation. Consequently, hydrogen is produced at a high rate of 76.9 mole H2 per gram Cr2O3@GaN per hour by only feeding ethanol, air, and light, leading to the achievement of a turnover number of 266,943,000 mole H2 per mole Cr2O3 over a long-term operation of 180 hours. Notably, an unprecedented light-to-hydrogen efficiency of 17.6 % is achieved under concentrated light illumination. The simultaneous generation of aldehyde from ethanol dehydrogenation enables the process more economically promising.

3.
Int J Mol Sci ; 23(12)2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35743157

RESUMO

Traumatic optic neuropathy (TON) is a significant cause of vision loss and irreversible blindness worldwide. It is defined as retinal ganglion cell death and axon degeneration caused by injury. Optic nerve crush (ONC), a well-validated model of TON, activates retinal microglia and initiates neuroinflammation. High-mobility group box 1 (HMGB1), a non-histone chromosomal binding protein in the nucleus of eukaryotic cells, is an important inducer of microglial activation and pro-inflammatory cytokine release. The purpose of this study was to examine the protective effects and mechanism of the HMGB1 inhibitor BoxA to neuroinflammation-induced retinal ganglion cells (RGCs) damage in traumatic optic neuropathy. For that purpose, an optic nerve crush model was established in C57BL/6J mice at 10-12 weeks. Model mice received an intravitreal injection of PBS and the HMGB1 inhibitor BoxA. Our data demonstrated that HMGB1 expression increased after optic nerve crush. Retinal ganglion cell function and morphology were damaged, and retinal ganglion cell numbers were reduced after optic nerve crush. Intravitreal injection of BoxA after ONC can alleviate damage. Furthermore, BoxA reduced microglial activation and expression levels of nuclear factor κB (NF-kB), nucleotide-binding domain, leucine-rich repeat containing protein 3 (NLRP3), and apoptosis-associated speck-like protein containing a CARD (ASC) in experimental ONC mice. In summary, HMGB1 mediates NLRP3 inflammasome via NF-kB to participate in retinal inflammatory injury after ONC. Thus, intravitreal injection of BoxA has potential therapeutic benefits for the effective treatment of RGC death to prevent TON.


Assuntos
Proteína HMGB1 , Traumatismos do Nervo Óptico , Animais , Modelos Animais de Doenças , Proteína HMGB1/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Compressão Nervosa , Doenças Neuroinflamatórias , Traumatismos do Nervo Óptico/tratamento farmacológico , Traumatismos do Nervo Óptico/metabolismo , Células Ganglionares da Retina/metabolismo
4.
Ecotoxicol Environ Saf ; 226: 112808, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34600290

RESUMO

Herein, green and non-toxic bismuth sulphide@graphitic carbon nitride (Bi2S3@g-C3N4) nanosheets (NCs) were firstly synthesized by ultrasonicated-assisted method and characterized with different tool. Bi2S3@g-C3N4 NCs antimicrobial activity tested against three types of microbes. As well the heterostructured Bi2S3@g-C3N4 NCs was investigated for removing dye and hexavalent chromium under visible light and showed high efficiency of photocatalytic oxidation/reduction higher than g-C3N4 alone, attributing to lower recombination photogenerated electron-hole pairs. Bi2S3@g-C3N4 NCs showed high antimicrobial efficiencies against Staphylococcus aureus (S. aureus) as a Gram positive bacterium, Escherichia coli (E. Coli)as a Gram negative bacterium and Candida albicans (C. albicans) and that the disinfection rates are 99.97%, 99.98% and 99.92%, respectively. The core mechanism is that the bacterial membrane could be destroyed by reactive oxygen species. The Bi2S3@g-C3N4 NCs is promising for environmental disinfection including water and public facilities disinfection and solar photocatalytic depollution. Turnover number (TON) and Turnover frequency (TOF) are used as concise assessment indicator for photocatalytic efficiency.


Assuntos
Anti-Infecciosos , Staphylococcus aureus , Catálise , Desinfecção , Escherichia coli
5.
J Bacteriol ; 202(2)2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-31636109

RESUMO

Filamentous phages are nonlytic viruses that specifically infect bacteria, establishing a persistent association with their host. The phage particle has no machinery for generating energy and parasitizes its host's existing structures in order to cross the bacterial envelope and deliver its genetic material. The import of filamentous phages across the bacterial periplasmic space requires some of the components of a macrocomplex of the envelope known as the Tol system. This complex uses the energy provided by the proton motive force (pmf) of the inner membrane to perform essential and highly energy-consuming functions of the cell, such as envelope integrity maintenance and cell division. It has been suggested that phages take advantage of pmf-driven conformational changes in the Tol system to transit across the periplasm. However, this hypothesis has not been formally tested. In order to decouple the role of the Tol system in cell physiology and during phage parasitism, we used mutations on conserved essential residues known for inactivating pmf-dependent functions of the Tol system. We identified impaired Tol complexes that remain fully efficient for filamentous phage uptake. We further demonstrate that the TolQ-TolR homologous motor ExbB-ExbD, normally operating with the TonB protein, is able to promote phage infection along with full-length TolA.IMPORTANCE Filamentous phages are widely distributed symbionts of Gram-negative bacteria, with some of them being linked to genome evolution and virulence of their host. However, the precise mechanism that permits their uptake across the cell envelope is poorly understood. The canonical phage model Fd requires the TolQRA protein complex in the host envelope, which is suspected to translocate protons across the inner membrane. In this study, we show that phage uptake proceeds in the presence of the assembled but nonfunctional TolQRA complex. Moreover, our results unravel an alternative route for phage import that relies on the ExbB-ExbD proteins. This work provides new insights into the fundamental mechanisms of phage infection and might be generalized to other filamentous phages responsible for pathogen emergence.


Assuntos
Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bacteriófagos/metabolismo , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Membrana/genética , Força Próton-Motriz/genética , Força Próton-Motriz/fisiologia
6.
Int J Mol Sci ; 21(2)2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31936081

RESUMO

The Ton complex is a molecular motor that uses the proton gradient at the inner membrane of Gram-negative bacteria to generate force and movement, which are transmitted to transporters at the outer membrane, allowing the entry of nutrients into the periplasmic space. Despite decades of investigation and the recent flurry of structures being reported by X-ray crystallography and cryoEM, the mode of action of the Ton molecular motor has remained elusive, and the precise stoichiometry of its subunits is still a matter of debate. This review summarizes the latest findings on the Ton system by presenting the recently reported structures and related reports on the stoichiometry of the fully assembled complex.


Assuntos
Proteínas de Bactérias/metabolismo , Bactérias Gram-Negativas/metabolismo , Proteínas de Membrana/metabolismo , Força Próton-Motriz , Proteínas de Bactérias/química , Escherichia coli/química , Escherichia coli/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Bactérias Gram-Negativas/química , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Proteínas de Membrana/química , Modelos Moleculares , Multimerização Proteica
7.
Development ; 143(6): 978-82, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26893344

RESUMO

Controlled cell division is central to the growth and development of all multicellular organisms. Within the proliferating zone of the Arabidopsis root, regular symmetric divisions give rise to patterns of parallel files of cells, the genetic basis of which remains unclear. We found that genotypes impaired in the TONNEAU1a (TON1a) gene display misoriented symmetric divisions in the epidermis and have no division defects in the underlying cortical tissue. The TON1a gene encodes a microtubule-associated protein. We show that in the ton1a mutant, epidermal and cortical cells do not form narrow, ring-like preprophase bands (PPBs), which are plant-specific, cytoskeletal structures that predict the position of the division plane before mitosis. The results indicate that in the cortex but not in the epidermis, division plane positioning and patterning can proceed correctly in the absence of both a functional TON1a and PPB formation. Differences between tissues in how they respond to the signals that guide symmetric division orientation during patterning might provide the basis for organised organ growth in the absence of cell movements.


Assuntos
Arabidopsis/citologia , Divisão Celular , Epiderme Vegetal/citologia , Raízes de Plantas/citologia , Alelos , Proteínas de Arabidopsis/genética , Meristema/citologia , Microtúbulos/metabolismo , Mutação/genética
8.
Planta ; 248(6): 1551-1567, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30191298

RESUMO

MAIN CONCLUSION: The subfamily II catalytic subunits of protein phosphatase 2A (PP2A) regulate the cortical microtubule dynamics in Arabidopsis, through interaction with TONNEAU2 (TON2)/FASS and modulation of α-tubulin dephosphorylation. Protein phosphatase 2A is a major protein phosphatase in eukaryotes that dephosphorylates many different substrates to regulate their function. PP2A is assembled into a heterotrimeric complex of scaffolding A subunit, regulatory B subunit, and catalytic C subunit. Plant PP2A catalytic C subunit (PP2AC) isoforms are classified into two subfamilies. In this study, we investigated the cellular functions of the Arabidopsis PP2AC subfamily II genes PP2AC-3 and PP2AC-4, particularly regarding the cortical microtubule (MT) organization. PP2AC-3 and PP2AC-4 strongly interacted with the B'' regulatory subunit TON2. Simultaneous silencing of PP2AC-3 and PP2AC-4 by virus-induced gene silencing (PP2AC-3,4 VIGS) significantly altered plant morphology in Arabidopsis, increasing cell numbers in leaves and stems. The leaf epidermis of PP2AC-3,4 VIGS plants largely lost its jigsaw-puzzle shape and exhibited reduced trichome branch numbers. VIGS of PP2AC-3,4 in Arabidopsis transgenic plants that expressed GFP-fused ß-tubulin 6 isoform (GFP-TUB6) for the visualization of MTs caused a reduction in the cortical MT array density in the pavement cells. VIGS of TON2 also led to similar cellular phenotypes and cortical MT patterns compared with those after VIGS of PP2AC-3,4, suggesting that PP2AC-3,4 and their interaction partner TON2 play a role in cortical MT organization in leaf epidermal cells. Furthermore, silencing of PP2AC-3,4 did not affect salt-induced phosphorylation of α-tubulin but delayed its dephosphorylation after salt removal. The reappearance of cortical MT arrays after salt removal was impaired in PP2AC-3,4 VIGS plants. These results suggest an involvement of PP2AC subfamily II in the regulation of cortical MT dynamics under normal and salt-stress conditions in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Regulação da Expressão Gênica de Plantas , Microtúbulos/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Proteína Fosfatase 2/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Domínio Catalítico , Proliferação de Células , Genes Reporter , Fosfoproteínas Fosfatases/genética , Fosforilação , Epiderme Vegetal/enzimologia , Epiderme Vegetal/genética , Epiderme Vegetal/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Isoformas de Proteínas , Proteína Fosfatase 2/genética , Subunidades Proteicas , Tricomas/enzimologia , Tricomas/genética , Tricomas/crescimento & desenvolvimento , Tubulina (Proteína)/metabolismo
9.
Biometals ; 30(1): 127-141, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28105572

RESUMO

Xanthomonas translucens pv. undulosa (Xtu) causes Bacterial Leaf Streak disease in the staple food crops such as wheat and barley. The survival strategies of pathogen and host are determined by the complex interactions occurring between the host plants and the pathogenic microbes. Iron binding proteins are important in the plant-microbe interactions as they are indulged in enzyme catalysis, virulence, metabolic and transport activities. In the presented study, we have identified that ~9.8% of Xtu proteome possess iron binding sequence motifs. Further, the analysis of Xtu proteome for secretory iron binding virulent proteins (IBVPs) revealed the fact that iron co-regulate the function of secretory proteins in virulence. We have found 26 secretory IBVPs and observed that these proteins are diverse in their biological functions ranging from transport to antimicrobial resistance, Reactive oxygen species detoxification and carbohydrate catabolism. The inferences may instigate to design the new strategies to combat and control the microbial diseases of staple food crops.


Assuntos
Proteínas de Ligação ao Ferro/química , Ferro/química , Proteoma/genética , Xanthomonas/química , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Metabolismo dos Carboidratos/genética , Ferro/metabolismo , Proteínas de Ligação ao Ferro/genética , Proteínas de Ligação ao Ferro/metabolismo , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Folhas de Planta/química , Folhas de Planta/genética , Triticum/microbiologia , Xanthomonas/genética
10.
Biochim Biophys Acta ; 1840(10): 3058-66, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24968987

RESUMO

BACKGROUND: For many pathogenic microorganisms, iron acquisition represents a significant stress during the colonization of a mammalian host. Heme is the single most abundant source of soluble iron in this environment. While the importance of iron assimilation for nearly all organisms is clear, the mechanisms by which heme is acquired and utilized by many bacterial pathogens, even those most commonly found at sites of infection, remain poorly understood. METHODS: An alternative protocol for the production and purification of the outer membrane hemoglobin receptor (HmbR) from the pathogen Neisseria meningitidis has facilitated a biophysical characterization of this outer membrane transporter by electronic absorption, circular dichroism, electron paramagnetic resonance, and resonance Raman techniques. RESULTS: HmbR co-purifies with 5-coordinate high spin ferric heme bound. The heme binding site accommodates exogenous imidazole as a sixth ligand, which results in a 6-coordinate, low-spin ferric species. Both the 5- and 6-coordinate complexes are reduced by sodium hydrosulfite. Four HmbR variants with a modest decrease in binding efficiency for heme have been identified (H87C, H280A, Y282A, and Y456C). These findings are consistent with an emerging paradigm wherein the ferric iron center of bound heme is coordinated by a tyrosine ligand. CONCLUSION: In summary, this study provides the first spectroscopic characterization for any heme or iron transporter in Neisseria meningitidis, and suggests a coordination environment heretofore unobserved in a TonB-dependent hemin transporter. GENERAL SIGNIFICANCE: A detailed understanding of the nutrient acquisition pathways in common pathogens such as N. meningitidis provides a foundation for new antimicrobial strategies.


Assuntos
Proteínas de Bactérias/química , Heme/química , Ferro/química , Neisseria meningitidis/química , Receptores de Superfície Celular/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Transporte Biológico Ativo/fisiologia , Heme/genética , Heme/metabolismo , Neisseria meningitidis/genética , Neisseria meningitidis/metabolismo , Ligação Proteica/fisiologia , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Análise Espectral
11.
Eur Arch Otorhinolaryngol ; 272(11): 3301-9, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25472815

RESUMO

Post-traumatic optic neuropathy (TON) is a rare, but very much feared event. It is a traumatic injury of the optic nerve at any level along its course (often inside the optic canal), with partial or total loss of visual acuity, temporarily or permanently. Until now, an univocal treatment strategy does not exist. The clinical records of 26 patients, treated from 2002 to 2013, were reviewed. The most frequent cause of injury was road traffic accident (63%), followed by iatrogenic damage, work injuries, sport or home accidents. All patients underwent pre-operative ophthalmological evaluation, neuro-imaging (angio-CT or angio-MRI scans) and systemic corticosteroid therapy. All patients required a surgical treatment, due to poor response to medical therapy; it consisted of an endonasal endoscopic decompression of the intracanalicular segment of the optic nerve, performed by removing the bony wall of the optical canal and releasing the perineural sheath. Improvement of visual acuity was reached in 65% of cases. No minor or major complication occurred intra- or post-operative, with a maximum follow-up time of 41 months. An improvement in visual acuity was achieved, although very limited in some cases, when surgery was performed as close as possible to the traumatic event. In the literature, there is no evidence-based data evaluating both of the two main treatment options (medical therapy versus surgical decompression), to state which is the gold standard in the treatment for TON. We discuss the pro and cons of our protocol: medical endovenous steroid treatment, within 8 h of injury, and endoscopic surgical decompression within 12-24 since the beginning of medical therapy, represent the best solution in terms of risk-benefit ratio for the patients.


Assuntos
Corticosteroides/uso terapêutico , Traumatismos Craniocerebrais/complicações , Descompressão Cirúrgica/métodos , Endoscopia/métodos , Procedimentos Neurocirúrgicos/métodos , Doenças do Nervo Óptico/etiologia , Acuidade Visual , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças do Nervo Óptico/fisiopatologia , Doenças do Nervo Óptico/terapia , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
12.
Proteins ; 82(6): 1072-8, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24265202

RESUMO

The crystal structure of Ton1535, a hypothetical protein from Thermococcus onnurineus NA1, was determined at 2.3 Å resolution. With two antiparallel α-helices in a helix-turn-helix motif as a repeating unit, Ton1535 consists of right-handed coiled N- and C-terminal regions that are stacked together using helix bundles containing a left-handed helical turn. One left-handed helical turn in the right-handed coiled structure produces two unique structural properties. One is the presence of separated concave grooves rather than one continuous concave groove, and the other is the contribution of α-helices on the convex surfaces of the N-terminal region to the extended surface of the concave groove of the C-terminal region and vice versa.


Assuntos
Proteínas Arqueais/química , Thermococcus , Sequência de Aminoácidos , Cristalografia por Raios X , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Dados de Sequência Molecular , Domínios e Motivos de Interação entre Proteínas , Estrutura Secundária de Proteína
13.
Sci Rep ; 14(1): 7514, 2024 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-38553505

RESUMO

This study aimed to assess the impact of light perception presence or absence on visual function recovery in patients with traumatic optic neuropathy (TON). A retrospective analysis was conducted on the clinical data of 206 TON patients. Based on the presence or absence of light perception after injury, patients were categorized into a light perception group and a non-light perception group. A comparison was made between the two groups regarding visual acuity recovery before and after treatment. The non-light perception group comprised 63 patients, with a treatment effectiveness rate of 39.68%. The light perception group consisted of 143 patients, with a treatment effectiveness rate of 74.83%. The difference between the two groups was statistically significant (χ2 = 23.464, P < 0.01). Subgroup analysis indicated that surgical treatment appeared to be more effective than steroid hormone therapy for patients with light perception. Conversely, for patients without light perception, there was no significant difference in the effectiveness of the two methods. The total effectiveness rate of the light perception group was significantly higher than that of the non-light perception group, suggesting that patients with light perception before treatment experience better outcomes compared to those without light perception. Treatment choices should be individualized to ensure optimal results.


Assuntos
Traumatismos do Nervo Óptico , Humanos , Traumatismos do Nervo Óptico/tratamento farmacológico , Recuperação de Função Fisiológica , Estudos Retrospectivos , Resultado do Tratamento , Acuidade Visual
14.
Quant Imaging Med Surg ; 14(1): 1086-1107, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38223128

RESUMO

Background and Objective: Diffusion tensor imaging (DTI) has been implemented in a breadth of scientific investigations of optic neuropathies, though it has yet to be fully adopted for diagnosis or prognosis. This is potentially due to a lack of standardization and weak replication of results. The aim of this investigation was to review DTI results from studies specific to three distinct optic neuropathies in order to probe its current clinical utility. Methods: We reviewed the DTI literature specific to primary open-angle glaucoma (POAG), optic neuritis (ON), and traumatic optic neuropathy (TON) by systematically searching the PubMed database on March 1st, 2023. Four distinct DTI metrics are considered: fractional anisotropy (FA), along with mean diffusivity (MD, axial diffusivity (AD), and radial diffusivity (RD). Results from within-group, between-group, and correlational studies were thoroughly assessed. Key Content and Findings: POAG studies most consistently report a decrease in FA, especially in the optic radiations, followed in prevalence by an increase in RD and then MD, whilst AD yields conflicting results between studies. It is notable that there is not an equal distribution of investigated DTI metrics, with FA utilized the most, followed by MD, RD, and AD. Studies of ON are similar in that the most consistent findings are specific to FA, RD, and MD. These results are specific to the optic nerve and radiation since only one study measured the intermediary regions. More studies are needed to assess the effect that ON has on the tracts of the visual system. Finally, only three studies assessing DTI of TON have been performed to date, displaying low to moderate replicability of results. To improve the level of agreement between studies assessing each optic neuropathy, an increased level of standardization is recommended. Conclusions: Both POAG and ON studies have yielded some prevalent DTI findings, both for contrast and correlation-based assessments. Although the clinical need is high for TON, considering the limitations of the current diagnostic tools, too few studies exist to make confident conclusions. Future use of standardized and longitudinal DTI, along with the foreseen methodological and technical improvements, is warranted to effectively study optic neuropathies.

15.
Chem Asian J ; : e202400674, 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39135419

RESUMO

The efficiency of catalysts relies on comprehending the underlying kinetics that govern their performance. Under the steady-state regime, the "rate" is referred to as the turnover frequency, where the reaction rate is first order with respect to catalysts. Here, we introduce the Maximum Kinetic Efficiency (MaxKinEff ) model, grounded in collision theory, to predict efficiency based on maximum turnover frequency, 𝛤max TOF0 and maximum turnover number, 𝜏max TON0. The model was applied to molecular water oxidation using twenty-six transition metal catalysts from the first (3d), second (4d), and third (5d) rows. A thorough investigation reveals that [Ru(pda)(Br-py)2] (pda = 1,10-phenanthroline-2,9-dicarboxylate; Py = pyridinophane) exhibits a notable 𝛤max TOF0 of 1176.87 × 10-5 s-1 due to its larger collision diameter (σ𝑅𝐶) and lower activation energy (E𝑎). Importantly, the trend in the computed 𝜏max TON0 values aligns with experimental TON, 𝜏experimental TON validating the model's accuracy. For instance, [Cp∗Ir(κ2-N,O)NO3] is identified by MaxKinEff as a standout performer, with the normalized maximum computed TON, 𝜏max TON0 resembling the experimental TON, 𝜏experimental TON = 2000.

16.
Biochem Biophys Res Commun ; 439(4): 533-8, 2013 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-24021277

RESUMO

Pantothenate is the essential precursor of coenzyme A (CoA), a fundamental cofactor in all aspects of metabolism. In bacteria and eukaryotes, pantothenate synthetase (PS) catalyzes the last step in the pantothenate biosynthetic pathway, and pantothenate kinase (PanK) phosphorylates pantothenate for its entry into the CoA biosynthetic pathway. However, genes encoding PS and PanK have not been identified in archaeal genomes. Recently, a comparative genomic analysis and the identification and characterization of two novel archaea-specific enzymes show that archaeal pantoate kinase (PoK) and phosphopantothenate synthetase (PPS) represent counterparts to the PS/PanK pathway in bacteria and eukaryotes. The TON1374 protein from Thermococcus onnurineus NA1 is a PPS, that shares 54% sequence identity with the first reported archaeal PPS candidate, MM2281, from Methanosarcina mazei and 91% sequence identity with TK1686, the PPS from Thermococcus kodakarensis. Here, we report the apo and ATP-complex structures of TON1374 and discuss the substrate-binding mode and reaction mechanism.


Assuntos
Proteínas Arqueais/química , Peptídeo Sintases/química , Thermococcus/enzimologia , Trifosfato de Adenosina/química , Trifosfato de Adenosina/metabolismo , Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , Cristalografia por Raios X , Cinética , Peptídeo Sintases/genética , Peptídeo Sintases/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/química , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Thermococcus/metabolismo
17.
Nutrients ; 15(14)2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37513596

RESUMO

This study aimed to adapt the Test of Orthorexia Nervosa- (TON-17) into Turkish and verify its validity and reliability. The study included 539 adults with a mean age of 30.2 ± 12.26 years. A reliability analysis was performed, along with a confirmatory factor analysis to test its construct validity. The time-invariance of the scale was examined by test-retest analysis, and its convergent validity was evaluated by a correlation analysis conducted to test the relationships between the scale and Eating Attitudes Test-26 and Obsessive Beliefs Questionnaire-9. Analyses were conducted using SPSS Version 28 and the AMOS-24 software. The Cronbach's α internal consistency coefficient of the total scale was found to be 0.82, suggesting a strong internal consistency. The Cronbach's α values of its factors were 0.68 for the "control of food quality", 0.64 for the "fixation on health and a healthy diet", and 0.73 for the "disorder symptoms". In addition, the test-retest reliability was found to be 0.87 for the total scale, suggesting excellent reliability. Most of the fit indices (CMIN/df, RMSEA, AGFI, NFI, and TLI) of the scale were acceptable, and the GFI indicated a good model fit. This study shows that the Turkish version of TON-17, which is a new tool with a three-factor structure to evaluate orthorexia, is a valid and reliable scale.


Assuntos
Comportamentos Relacionados com a Saúde , Ortorexia Nervosa , Adulto , Humanos , Adolescente , Adulto Jovem , Reprodutibilidade dos Testes , Psicometria , Dieta Saudável , Inquéritos e Questionários
18.
Front Cell Neurosci ; 17: 1145574, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37293627

RESUMO

Traumatic optic neuropathy (TON) is a condition that causes massive loss of retinal ganglion cells (RGCs) and their axonal fibers, leading to visual insufficiency. Several intrinsic and external factors can limit the regenerative ability of RGC after TON, subsequently resulting in RGC death. Hence, it is important to investigate a potential drug that can protect RGC after TON and enhance its regenerative capacity. Herein, we investigated whether Huperzine A (HupA), extracted from a Chinese herb, has neuroprotective effects and may enhance neuronal regeneration following the optic nerve crush (ONC) model. We compared the three modes of drug delivery and found that intravitreal injection of HupA could promote RGC survival and axonal regeneration after ONC. Mechanistically, HupA exerted its neuroprotective and axonal regenerative effects through the mTOR pathway; these effects could be blocked by rapamycin. To sum up, our findings suggest a promising application of HupA in the clinical treatment of traumatic optic nerve.

19.
Ophthalmol Sci ; 3(1): 100217, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36275202

RESUMO

Purpose: To identify optic nerve (ON) lipid alterations associated with sonication-induced traumatic optic neuropathy (TON). Design: Experimental study. Subjects: A mouse model of indirect TON was generated using sound energy concentrated focally at the entrance of the optic canal using a laboratory sonifier with a microtip probe. Methods: Analyses of datasets generated from high-performance liquid chromatography-electrospray tandem mass spectrometry of ONs dissected from the head of the ON to the optic chiasm at 1 day, 7 days, and 14 days postsonication compared with that in nonsonicated controls. Main Outcome Measures: Lipid abundance alterations in postsonicated ONs were evaluated using 1-way analysis of variance (false discovery rate-adjusted significant P value < 0.01), lipid-related gene sets, biochemical properties, and receiver operating characteristic to identify lipids associated with optic neuropathy. Results: There were 28 lipid species with significantly different abundances across the control and postsonication groups. The 2 most significantly upregulated lipids included a sphingomyelin (SM) species, SM(d40:7), and a hexosylceramide (CerG1) species, CerG1(d18:1/24:2). Hexosylceramide (d18:1/24:2) was noted to have a stepwise increasing trend from day 1 to day 14 after sonication-induced optic neuropathy. Investigation of biophysical properties showed notable enrichment of lipids with high and above-average transition temperatures at day 14 after sonication. Lipid-related gene set analysis revealed enrichment in sphingolipid and glycosphingolipid metabolic processes. The best classifier to differentiate day 14 postsonication from controls, based on area under the receiver operating characteristic curve, was CerG1(d18:1/24:2) (area under the receiver operating characteristic curve: 1). Conclusions: Temporal alterations in sphingolipid metabolism and biochemical properties were observed in the ON of mice after sonication-induced optic neuropathy, with notable elevations in sphingomyelin and hexosylceramide species. Hexosylceramide (d18:1/24:2) may be associated with damage after indirect trauma, indicating that lipid membrane abnormalities may be a mediator of pathology due to trauma.

20.
Math Biosci Eng ; 19(10): 10550-10580, 2022 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-36032006

RESUMO

The Internet of Things (IoT) is a paradigm that connects a range of physical smart devices to provide ubiquitous services to individuals and automate their daily tasks. IoT devices collect data from the surrounding environment and communicate with other devices using different communication protocols such as CoAP, MQTT, DDS, etc. Study shows that these protocols are vulnerable to attack and prove a significant threat to IoT telemetry data. Within a network, IoT devices are interdependent, and the behaviour of one device depends on the data coming from another device. An intruder exploits vulnerabilities of a device's interdependent feature and can alter the telemetry data to indirectly control the behaviour of other dependent devices in a network. Therefore, securing IoT devices have become a significant concern in IoT networks. The research community often proposes intrusion Detection Systems (IDS) using different techniques. One of the most adopted techniques is machine learning (ML) based intrusion detection. This study suggests a stacking-based ensemble model makes IoT devices more intelligent for detecting unusual behaviour in IoT networks. The TON-IoT (2020) dataset is used to assess the effectiveness of the proposed model. The proposed model achieves significant improvements in accuracy and other evaluation measures in binary and multi-class classification scenarios for most of the sensors compared to traditional ML algorithms and other ensemble techniques.


Assuntos
Internet das Coisas , Algoritmos , Humanos , Aprendizado de Máquina , Telemetria
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