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1.
Nature ; 568(7751): 216-220, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30971839

RESUMO

Phosphorene is a mono-elemental, two-dimensional (2D) substance with outstanding, highly directional properties and a bandgap that depends on the number of layers of the material1-8. Nanoribbons, meanwhile, combine the flexibility and unidirectional properties of one-dimensional nanomaterials, the high surface area of 2D nanomaterials and the electron-confinement and edge effects of both. The structures of nanoribbons can thus lead to exceptional control over electronic band structure, the emergence of novel phenomena and unique architectures for applications5,6,9-24. Phosphorene's intrinsically anisotropic structure has motivated numerous theoretical calculations of phosphorene nanoribbons (PNRs), predicting extraordinary properties5,6,12-24. So far, however, discrete PNRs have not been produced. Here we present a method for creating quantities of high-quality, individual PNRs by ionic scissoring of macroscopic black phosphorus crystals. This top-down process results in stable liquid dispersions of PNRs with typical widths of 4-50 nm, predominantly single-layer thickness, measured lengths of up to 75 µm and aspect ratios of up to 1,000. The nanoribbons are atomically flat single crystals, aligned exclusively in the zigzag crystallographic orientation. The ribbons have remarkably uniform widths along their entire lengths, and are extremely flexible. These properties-together with the ease of downstream manipulation via liquid-phase methods-should enable the search for predicted exotic states6,12-14,17-19,21, and an array of applications in which PNRs have been predicted to offer transformative advantages. These applications range from thermoelectric devices to high-capacity fast-charging batteries and integrated high-speed electronic circuits6,14-16,20,23,24.

2.
J Am Chem Soc ; 146(18): 12601-12608, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38687243

RESUMO

The burgeoning necessity to discover new methodologies for the synthesis of long-chain hydrocarbons and oxygenates, independent of traditional reliance on high-temperature, high-pressure, and fossil fuel-based carbon, is increasingly urgent. In this context, we introduce a nonthermal plasma-based strategy for the initiation and propagation of long-chain carbon growth from biogas constituents (CO2 and CH4). Utilizing a plasma reactor operating at atmospheric room temperature, our approach facilitates hydrocarbon chain growth up to C40 in the solid state (including oxygenated products), predominantly when CH4 exceeds CO2 in the feedstock. This synthesis is driven by the hydrogenation of CO2 and/or amalgamation of CHx radicals. Global plasma chemistry modeling underscores the pivotal role of electron temperature and CHx radical genesis, contingent upon varying CO2/CH4 ratios in the plasma system. Concomitant with long-chain hydrocarbon production, the system also yields gaseous products, primarily syngas (H2 and CO), as well as liquid-phase alcohols and acids. Our finding demonstrates the feasibility of atmospheric room-temperature synthesis of long-chain hydrocarbons, with the potential for tuning the chain length based on the feed gas composition.

3.
Gene Ther ; 30(5): 443-454, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36450833

RESUMO

CRISPR-based gene editing technology represents a promising approach to deliver therapies for inherited disorders, including amyotrophic lateral sclerosis (ALS). Toxic gain-of-function superoxide dismutase 1 (SOD1) mutations are responsible for ~20% of familial ALS cases. Thus, current clinical strategies to treat SOD1-ALS are designed to lower SOD1 levels. Here, we utilized AAV-PHP.B variants to deliver CRISPR-Cas9 guide RNAs designed to disrupt the human SOD1 (huSOD1) transgene in SOD1G93A mice. A one-time intracerebroventricular injection of AAV.PHP.B-huSOD1-sgRNA into neonatal H11Cas9 SOD1G93A mice caused robust and sustained mutant huSOD1 protein reduction in the cortex and spinal cord, and restored motor function. Neonatal treatment also reduced spinal motor neuron loss, denervation at neuromuscular junction (NMJ) and muscle atrophy, diminished axonal damage and preserved compound muscle action potential throughout the lifespan of treated mice. SOD1G93A treated mice achieved significant disease-free survival, extending lifespan by more than 110 days. Importantly, a one-time intrathecal or intravenous injection of AAV.PHP.eB-huSOD1-sgRNA in adult H11Cas9 SOD1G93A mice, immediately before symptom onset, also extended lifespan by at least 170 days. We observed substantial protection against disease progression, demonstrating the utility of our CRISPR editing preclinical approach for target evaluation. Our approach uncovered key parameters (e.g., AAV capsid, Cas9 expression) that resulted in improved efficacy compared to similar approaches and can also serve to accelerate drug target validation.


Assuntos
Esclerose Lateral Amiotrófica , Camundongos , Humanos , Animais , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/terapia , Superóxido Dismutase-1/genética , Edição de Genes , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Camundongos Transgênicos , Modelos Animais de Doenças
4.
J Am Chem Soc ; 145(51): 28233-28239, 2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38103175

RESUMO

By inducing CO2-pulsed discharges within microchannel bubbles and regulating thus-forming plasma microbubbles, we observe high-performance, catalyst-free coformation of hydrogen peroxide (H2O2) and oxalate directly from CO2 and water. With isotope-labeled C18O2 as the feedstock, peaks of H218O16O and H216O2 observed by ex situ surface-enhanced Raman spectra indicate that single-atom oxygen (O) from CO2 dissociations and H2O-derived OH radicals both contribute to H2O2 formation. The global plasma chemistry modeling suggests that high-density, energy-intense electron supply enables high-density CO2- (aq) and HCO2- (aq) formation and their subsequent coupling to produce oxalate. The enhanced solvation of CO2, facilitated by the efficient transport of CxOy ionic species and CO, is demonstrated as a crucial benefit of spark discharges interacting with water at the bubble interface. We expect this plasma microbubble approach to provide a novel power-to-chemical avenue to convert CO2 into valuable H2O2 and oxalic acid platform chemicals, thus leveraging renewable energy resources.

5.
Bioorg Med Chem Lett ; 80: 129108, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36538993

RESUMO

For the past two decades, BTK a tyrosine kinase and member of the Tec family has been a drug target of significant interest due to its potential to selectively treat various B cell-mediated diseases such as CLL, MCL, RA, and MS. Owning to the challenges encountered in identifying drug candidates exhibiting the potency block B cell activation via BTK inhibition, the pharmaceutical industry has relied on the use of covalent/irreversible inhibitors to address this unmet medical need. Herein, we describe a medicinal chemistry campaign to identify structurally diverse reversible BTK inhibitors originating from HITS identified using a fragment base screen. The leads were optimized to improve the potency and in vivo ADME properties resulting in a structurally distinct chemical series used to develop and validate a novel in vivo CD69 and CD86 PD assay in rodents.


Assuntos
Inibidores de Proteínas Quinases , Proteínas Tirosina Quinases , Camundongos , Animais , Tirosina Quinase da Agamaglobulinemia , Inibidores de Proteínas Quinases/química , Modelos Animais de Doenças , Antígeno B7-2
6.
Crit Rev Food Sci Nutr ; 62(21): 5925-5949, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33764212

RESUMO

In the last decades, different non-thermal and thermal technologies have been developed for food processing. However, in many cases, it is not clear which experimental parameters must be reported to guarantee the experiments' reproducibility and provide the food industry a straightforward way to scale-up these technologies. Since reproducibility is one of the most important science features, the current work aims to improve the reproducibility of studies on emerging technologies for food processing by providing guidelines on reporting treatment conditions of thermal and non-thermal technologies. Infrared heating, microwave heating, ohmic heating and radiofrequency heating are addressed as advanced thermal technologies and isostatic high pressure, ultra-high-pressure homogenization sterilization, high-pressure homogenization, microfluidization, irradiation, plasma technologies, power ultrasound, pressure change technology, pulsed electric fields, pulsed light and supercritical CO2 are approached as non-thermal technologies. Finally, growing points and perspectives are highlighted.


Assuntos
Conservação de Alimentos , Temperatura Alta , Manipulação de Alimentos , Pressão , Reprodutibilidade dos Testes
7.
Brain ; 144(8): 2361-2374, 2021 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-34145876

RESUMO

Autoantibodies are a hallmark of numerous neurological disorders, including multiple sclerosis, autoimmune encephalitides and neuromyelitis optica. Whilst well understood in peripheral myeloid cells, the pathophysiological significance of autoantibody-induced Fc receptor signalling in microglia remains unknown, in part due to the lack of a robust in vivo model. Moreover, the application of therapeutic antibodies for neurodegenerative disease also highlights the importance of understanding Fc receptor signalling in microglia. Here, we describe a novel in vivo experimental paradigm that allows for selective engagement of Fc receptors within the CNS by peripherally injecting anti-myelin oligodendrocyte glycoprotein (MOG) monoclonal antibodies into normal wild-type mice. MOG antigen-bound immunoglobulins were detected throughout the CNS and triggered a rapid and tightly regulated proliferative response in both brain and spinal cord microglia. This microglial response was abrogated when anti-MOG antibodies were deprived of Fc receptor effector function or injected into Fcγ receptor knockout mice and was associated with the downregulation of Fc receptors in microglia, but not peripheral myeloid cells, establishing that this response was dependent on central Fc receptor engagement. Downstream of the Fc receptors, BTK was a required signalling node for this response, as microglia proliferation was amplified in BtkE41K knock-in mice expressing a constitutively active form of the enzyme and blunted in mice treated with a CNS-penetrant small molecule inhibitor of BTK. Finally, this response was associated with transient and stringently regulated changes in gene expression predominantly related to cellular proliferation, which markedly differed from transcriptional programs typically associated with Fc receptor engagement in peripheral myeloid cells. Together, these results establish a physiologically-meaningful functional response to Fc receptor and BTK signalling in microglia, while providing a novel in vivo tool to further dissect the roles of microglia-specific Fc receptor and BTK-driven responses to both pathogenic and therapeutic antibodies in CNS homeostasis and disease.


Assuntos
Tirosina Quinase da Agamaglobulinemia/metabolismo , Autoanticorpos/imunologia , Encéfalo/patologia , Microglia/patologia , Glicoproteína Mielina-Oligodendrócito/imunologia , Receptores Fc/metabolismo , Medula Espinal/patologia , Animais , Encéfalo/imunologia , Encéfalo/metabolismo , Proliferação de Células/fisiologia , Camundongos , Microglia/imunologia , Microglia/metabolismo , Medula Espinal/imunologia , Medula Espinal/metabolismo
8.
J Appl Microbiol ; 132(4): 2490-2500, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34957649

RESUMO

AIMS: This study aimed to compare the efficacy of plasma-activated water (PAW) generated by two novel plasma reactors against pathogenic foodborne illness organisms. METHODS AND RESULTS: The antimicrobial efficacy of PAW produced by a bubble spark discharge (BSD) reactor and a dielectric barrier discharge-diffuser (DBDD) reactor operating at atmospheric conditions with air, multiple discharge frequencies and Milli-Q and tap water, was investigated with model organisms Listeria innocua and Escherichia coli in situ. Optimal conditions were subsequently employed for pathogenic bacteria Listeria monocytogenes, E. coli and Salmonella enterica. DBDD-PAW reduced more than 6-log of bacteria within 1 min. The BSD-PAW, while attaining high log reduction, was less effective. Analysis of physicochemical properties revealed that BSD-PAW had a greater variety of reactive species than DBDD-PAW. Scavenger assays designed to specifically sequester reactive species demonstrated a critical role of superoxide, particularly in DBDD-PAW. CONCLUSIONS: DBDD-PAW demonstrated rapid antimicrobial activity against pathogenic bacteria, with superoxide the critical reactive species. SIGNIFICANCE AND IMPACT OF STUDY: This study demonstrates the potential of DBDD-PAW produced using tap water and air as a feasible and cost-effective option for antimicrobial applications, including food safety.


Assuntos
Anti-Infecciosos , Listeria monocytogenes , Listeria , Gases em Plasma , Anti-Infecciosos/farmacologia , Contagem de Colônia Microbiana , Escherichia coli , Microbiologia de Alimentos , Gases em Plasma/farmacologia , Água/química
9.
Bioorg Med Chem ; 44: 116275, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34314938

RESUMO

Bruton's tyrosine kinase (BTK) is an essential node on the BCR signaling in B cells, which are clinically validated to play a critical role in B-cell lymphomas and various auto-immune diseases such as Multiple Sclerosis (MS), Pemphigus, and rheumatoid arthritis (RA). Although non-selective irreversible BTK inhibitors have been approved for oncology, due to the emergence of drug resistance in B-cell lymphoma associated with covalent inhibitor, there an unmet medical need to identify reversible, selective, potent BTK inhibitor as viable therapeutics for patients. Herein, we describe the identification of Hits and subsequence optimization to improve the physicochemical properties, potency and kinome selectivity leading to the discovery of a novel class of BTK inhibitors. Utilizing Met ID and structure base design inhibitors were synthesized with increased in vivo metabolic stability and oral exposure in rodents suitable for advancing to lead optimization.


Assuntos
Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Descoberta de Drogas , Inibidores de Proteínas Quinases/farmacocinética , Tirosina Quinase da Agamaglobulinemia/metabolismo , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/metabolismo , Relação Estrutura-Atividade
10.
Nanomedicine ; 36: 102436, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34153528

RESUMO

Platinum nanoparticles (PtNPs) have been investigated for their antioxidant abilities in a range of biological and other applications. The ability to reduce off-target cold atmospheric plasma (CAP) cytotoxicity would be useful in Plasma Medicine; however, little has been published to date about the ability of PtNPs to reduce or inhibit the effects of CAP. Here we investigate whether PtNPs can protect against CAP-induced cytotoxicity in cancerous and non-cancerous cell lines. PtNPs were shown to dramatically reduce intracellular reactive species (RONS) production in U-251 MG cells. However, RONS generation was unaffected by PtNPs in medium without cells. PtNPs protect against CAP induced mitochondrial membrane depolarization, but not cell membrane permeabilization which is a CAP-induced RONS-independent event. PtNPs act as potent intracellular scavengers of reactive species and can protect against CAP induced cytotoxicity. PtNPs, showing no significant biocorrosion, may be useful as a catalytic antioxidant for healthy tissue and for protecting against CAP-induced tissue damage.


Assuntos
Citotoxinas/efeitos adversos , Nanopartículas Metálicas , Estresse Oxidativo/efeitos dos fármacos , Gases em Plasma/efeitos adversos , Platina , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular Tumoral , Citotoxinas/farmacologia , Células HEK293 , Humanos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/uso terapêutico , Gases em Plasma/farmacologia , Platina/química , Platina/farmacologia
11.
Appl Environ Microbiol ; 86(9)2020 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-32086309

RESUMO

Atmospheric cold plasma (ACP) treatment is an emerging food technology for product safety and quality retention, shelf-life extension, and sustainable processing. The activated chemical species of ACP can act rapidly against microorganisms without leaving chemical residues on food surfaces. The main objectives of this study were to investigate the efficiency and mechanisms of inactivation of fungal spores and biofilms by ACP and to understand the effects of the gas-mediated and liquid-mediated modes of application against important fungal contaminants. Aspergillus flavus was selected as the model microorganism. A. flavus spores were exposed to either gas plasma (GP) or plasma-activated water (PAW), whereas gas plasma alone was used to treat A. flavus biofilms. This study demonstrated that both GP and PAW treatments independently resulted in significant decreases of A. flavus metabolic activity and spore counts, with maximal reductions of 2.2 and 0.6 log10 units for GP and PAW, respectively. The characterization of the reactive oxygen and nitrogen species in PAW and spore suspensions indicated that the concentration of secondary reactive species was an important factor influencing the antimicrobial activity of the treatment. The biofilm study showed that GP had detrimental effects on biofilm structure; however, the initial inoculum concentration prior to biofilm formation can be a crucial factor influencing the fungicidal effects of ACP.IMPORTANCE The production of mycotoxin-free food remains a challenge in both human and animal food chains. A. flavus, a mycotoxin-producing contaminant of economically important crops, was selected as the model microorganism to investigate the efficiency and mechanisms of ACP technology against fungal contaminants of food. Our study directly compares the antifungal properties of gas plasma (GP) and plasma-activated water (PAW) against fungi as well as reporting the effects of ACP treatment on biofilms produced by A. flavus.


Assuntos
Antifúngicos/farmacologia , Aspergillus flavus/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Gases em Plasma/farmacologia , Esporos Fúngicos/efeitos dos fármacos , Água/farmacologia , Aspergillus flavus/fisiologia , Contagem de Colônia Microbiana , Contaminação de Alimentos/prevenção & controle , Esporos Fúngicos/fisiologia
12.
Arch Biochem Biophys ; 689: 108462, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32590068

RESUMO

Silver nanoparticles (AgNP) emerged as a promising reagent for cancer therapy with oxidative stress implicated in the toxicity. Meanwhile, studies reported cold atmospheric plasma (CAP) generation of reactive oxygen and nitrogen species has selectivity towards cancer cells. Gold nanoparticles display synergistic cytotoxicity when combined with CAP against cancer cells but there is a paucity of information using AgNP, prompting to investigate the combined effects of CAP using dielectric barrier discharge system (voltage of 75 kV, current is 62.5 mA, duty cycle of 7.5kVA and input frequency of 50-60Hz) and 10 nm PVA-coated AgNP using U373MG Glioblastoma Multiforme cells. Cytotoxicity in U373MG cells was >100-fold greater when treated with both CAP and PVA-AgNP compared with either therapy alone (IC50 of 4.30 µg/mL with PVA-AgNP alone compared with 0.07 µg/mL after 25s CAP and 0.01 µg/mL 40s CAP). Combined cytotoxicity was ROS-dependent and was prevented using N-Acetyl Cysteine. A novel darkfield spectral imaging method investigated and quantified AgNP uptake in cells determining significantly enhanced uptake, aggregation and subcellular accumulation following CAP treatment, which was confirmed and quantified using atomic absorption spectroscopy. The results indicate that CAP decreases nanoparticle size, decreases surface charge distribution of AgNP and induces uptake, aggregation and enhanced cytotoxicity in vitro.


Assuntos
Neoplasias Encefálicas/terapia , Glioblastoma/terapia , Gases em Plasma/farmacologia , Prata/farmacologia , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Glioblastoma/metabolismo , Humanos , Nanopartículas Metálicas/análise , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Prata/farmacocinética
13.
Proc Natl Acad Sci U S A ; 114(12): E2347-E2356, 2017 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-28270613

RESUMO

Spinal muscular atrophy (SMA), an autosomal recessive neuromuscular disease, is the leading monogenic cause of infant mortality. Homozygous loss of the gene survival of motor neuron 1 (SMN1) causes the selective degeneration of lower motor neurons and subsequent atrophy of proximal skeletal muscles. The SMN1 protein product, survival of motor neuron (SMN), is ubiquitously expressed and is a key factor in the assembly of the core splicing machinery. The molecular mechanisms by which disruption of the broad functions of SMN leads to neurodegeneration remain unclear. We used an antisense oligonucleotide (ASO)-based inducible mouse model of SMA to investigate the SMN-specific transcriptome changes associated with neurodegeneration. We found evidence of widespread intron retention, particularly of minor U12 introns, in the spinal cord of mice 30 d after SMA induction, which was then rescued by a therapeutic ASO. Intron retention was concomitant with a strong induction of the p53 pathway and DNA damage response, manifesting as γ-H2A.X positivity in neurons of the spinal cord and brain. Widespread intron retention and markers of the DNA damage response were also observed with SMN depletion in human SH-SY5Y neuroblastoma cells and human induced pluripotent stem cell-derived motor neurons. We also found that retained introns, high in GC content, served as substrates for the formation of transcriptional R-loops. We propose that defects in intron removal in SMA promote DNA damage in part through the formation of RNA:DNA hybrid structures, leading to motor neuron death.


Assuntos
Dano ao DNA , Íntrons , Atrofia Muscular Espinal/metabolismo , Proteína 1 de Sobrevivência do Neurônio Motor/genética , Proteína 1 de Sobrevivência do Neurônio Motor/metabolismo , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Neurônios Motores/metabolismo , Atrofia Muscular Espinal/genética , Oligonucleotídeos Antissenso/genética , Oligonucleotídeos Antissenso/metabolismo , Splicing de RNA
14.
Bioorg Med Chem ; 27(13): 2905-2913, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31138459

RESUMO

Since the approval of ibrutinib for the treatment of B-cell malignancies in 2012, numerous clinical trials have been reported using covalent inhibitors to target Bruton's tyrosine kinase (BTK) for oncology indications. However, a formidable challenge for the pharmaceutical industry has been the identification of reversible, selective, potent molecules for inhibition of BTK. Herein, we report application of Tethering-fragment-based screens to identify low molecular weight fragments which were further optimized to improve on-target potency and ADME properties leading to the discovery of reversible, selective, potent BTK inhibitors suitable for pre-clinical proof-of-concept studies.


Assuntos
Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Inibidores de Proteínas Quinases/uso terapêutico , Humanos , Inibidores de Proteínas Quinases/farmacologia
15.
J Immunol ; 197(10): 3806-3819, 2016 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-27815440

RESUMO

Despite being one of the most common rheumatologic diseases, there is still no disease-modifying drug for primary Sjögren's syndrome (pSS). Advancing our knowledge of the target tissue has been limited by the low dimensionality of histology techniques and the small size of human salivary gland biopsies. In this study, we took advantage of a molecularly validated mouse model of pSS to characterize tissue-infiltrating CD4+ T cells and their regulation by the lymphotoxin/LIGHT signaling axis. Novel cell subsets were identified by combining highly dimensional flow and mass cytometry with transcriptomic analyses. Pharmacologic modulation of the LTßR signaling pathway was achieved by treating mice with LTßR-Ig, a therapeutic intervention currently being tested in pSS patients (Baminercept trial NCT01552681). Using these approaches, we identified two novel CD4+ T cell subsets characterized by high levels of PD1: Prdm1+ effector regulatory T cells expressing immunoregulatory factors, such as Il10, Areg, Fgl2, and Itgb8, and Il21+ effector conventional T cells expressing a pathogenic transcriptional signature. Mirroring these observations in mice, large numbers of CD4+PD1+ T cells were detected in salivary glands from Sjögren's patients but not in normal salivary glands or kidney biopsies from lupus nephritis patients. Unexpectedly, LTßR-Ig selectively halted the recruitment of PD1- naive, but not PD1+, effector T cells to the target tissue, leaving the cells with pathogenic potential unaffected. Altogether, this study revealed new cellular players in pSS pathogenesis, their transcriptional signatures, and differential dependency on the lymphotoxin/LIGHT signaling axis that help to interpret the negative results of the Baminercept trial and will guide future therapeutic interventions.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Receptor beta de Linfotoxina/metabolismo , Linfotoxina-alfa/metabolismo , Glândulas Salivares/imunologia , Síndrome de Sjogren/imunologia , Síndrome de Sjogren/fisiopatologia , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral/metabolismo , Anfirregulina/genética , Animais , Biópsia , Ensaios Clínicos como Assunto , Modelos Animais de Doenças , Citometria de Fluxo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Interleucina-10/genética , Interleucinas/genética , Rim/patologia , Nefrite Lúpica/imunologia , Linfotoxina-alfa/genética , Camundongos , Glândulas Salivares/patologia , Transdução de Sinais , Síndrome de Sjogren/terapia , Subpopulações de Linfócitos T/imunologia , Linfócitos T Reguladores
16.
Nano Lett ; 17(10): 5891-5896, 2017 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-28678518

RESUMO

A primary method for the production of 2D nanosheets is liquid-phase delamination from their 3D layered bulk analogues. Most strategies currently achieve this objective by significant mechanical energy input or chemical modification but these processes are detrimental to the structure and properties of the resulting 2D nanomaterials. Bulk poly(triazine imide) (PTI)-based carbon nitrides are layered materials with a high degree of crystalline order. Here, we demonstrate that these semiconductors are spontaneously soluble in select polar aprotic solvents, that is, without any chemical or physical intervention. In contrast to more aggressive exfoliation strategies, this thermodynamically driven dissolution process perfectly maintains the crystallographic form of the starting material, yielding solutions of defect-free, hexagonal 2D nanosheets with a well-defined size distribution. This pristine nanosheet structure results in narrow, excitation-wavelength-independent photoluminescence emission spectra. Furthermore, by controlling the aggregation state of the nanosheets, we demonstrate that the emission wavelengths can be tuned from narrow UV to broad-band white. This has potential applicability to a range of optoelectronic devices.

17.
Compr Rev Food Sci Food Saf ; 17(5): 1379-1394, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33350151

RESUMO

Understanding the impact of nonthermal plasma (NTP) technology on key nutritional and functional food components is of paramount importance for the successful adoption of the technology by industry. NTP technology (NTPT) has demonstrated marked antimicrobial efficacies with good retention of important physical, chemical, sensory, and nutritional parameters for an array of food products. This paper presents the influence of NTPT on selected functional food components with a focus on low-molecular-weight bioactive compounds and vitamins. We discuss the mechanisms of bioactive compound alteration by plasma-reactive species and classify their influence on vitamins and their antioxidant capacities. The impact of NTP on specific bioactive compounds depends both on plasma properties and the food matrix. Induced changes are mainly associated with oxidative degradation and cleavage of double bonds in organic compounds. The effects reported to date are mainly time-dependent increases in the concentrations of polyphenols, vitamin C, or increases in antioxidant activity. Also, improvement in the extraction efficiency of polyphenols is observed. The review highlights future research needs regarding the complex mechanisms of interaction with plasma species. NTP is a novel technology that can both negatively and positively affect the functional components in food.

18.
Learn Mem ; 24(11): 589-596, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29038220

RESUMO

Numerous studies have indicated that the consolidation of contextual fear memories supported by an aversive outcome like footshock requires de novo protein synthesis as well as protein degradation mediated by the ubiquitin-proteasome system (UPS). Context memory formed in the absence of an aversive stimulus by simple exposure to a novel environment requires de novo protein synthesis in both the dorsal (dHPC) and ventral (vHPC) hippocampus. However, the role of UPS-mediated protein degradation in the consolidation of context memory in the absence of a strong aversive stimulus has not been investigated. In the present study, we used the context preexposure facilitation effect (CPFE) procedure, which allows for the dissociation of context learning from context-shock learning, to investigate the role of activity-dependent protein degradation in the dHPC and vHPC during the formation of a context memory. We report that blocking protein degradation with the proteasome inhibitor clasto-lactacystin ß-lactone (ßLac) or blocking protein synthesis with anisomycin (ANI) immediately after context preexposure significantly impaired context memory formation. Additionally, we examined 20S proteasome activity at different time points following context exposure and saw that the activity of proteasomes in the dHPC increases immediately after stimulus exposure while the vHPC exhibits a biphasic pattern of proteolytic activity. Taken together, these data suggest that the requirement of increased proteolysis during memory consolidation is not driven by processes triggered by the strong aversive outcome (i.e., shock) normally used to support fear conditioning.


Assuntos
Condicionamento Clássico/fisiologia , Medo/fisiologia , Hipocampo/fisiologia , Memória/fisiologia , Proteólise , Análise de Variância , Animais , Anisomicina/farmacologia , Condicionamento Clássico/efeitos dos fármacos , Inibidores de Cisteína Proteinase/farmacologia , Medo/efeitos dos fármacos , Reação de Congelamento Cataléptica/efeitos dos fármacos , Reação de Congelamento Cataléptica/fisiologia , Hipocampo/efeitos dos fármacos , Lactonas/farmacologia , Masculino , Memória/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores da Síntese de Proteínas/farmacologia , Proteólise/efeitos dos fármacos , Ratos , Ratos Long-Evans , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismo , Fatores de Tempo
19.
Learn Mem ; 24(9): 414-421, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28814467

RESUMO

Generalization of fear can involve abnormal responding to cues that signal safety and is common in people diagnosed with post-traumatic stress disorder. Differential auditory fear conditioning can be used as a tool to measure changes in fear discrimination and generalization. Most prior work in this area has focused on elevated amygdala activity as a critical component underlying generalization. The amygdala receives input from auditory cortex as well as the medial geniculate nucleus (MgN) of the thalamus, and these synapses undergo plastic changes in response to fear conditioning and are major contributors to the formation of memory related to both safe and threatening cues. The requirement for MgN protein synthesis during auditory discrimination and generalization, as well as the role of MgN plasticity in amygdala encoding of discrimination or generalization, have not been directly tested. GluR1 and GluR2 containing AMPA receptors are found at synapses throughout the amygdala and their expression is persistently up-regulated after learning. Some of these receptors are postsynaptic to terminals from MgN neurons. We found that protein synthesis-dependent plasticity in MgN is necessary for elevated freezing to both aversive and safe auditory cues, and that this is accompanied by changes in the expressions of AMPA receptor and synaptic scaffolding proteins (e.g., SHANK) at amygdala synapses. This work contributes to understanding the neural mechanisms underlying increased fear to safety signals after stress.


Assuntos
Tonsila do Cerebelo/fisiologia , Condicionamento Clássico/fisiologia , Discriminação Psicológica/fisiologia , Medo/fisiologia , Corpos Geniculados/fisiologia , Memória/fisiologia , Vias Neurais/fisiologia , Estimulação Acústica/efeitos adversos , Análise de Variância , Animais , Anisomicina/farmacologia , Condicionamento Clássico/efeitos dos fármacos , Discriminação Psicológica/efeitos dos fármacos , Proteína 4 Homóloga a Disks-Large/metabolismo , Medo/efeitos dos fármacos , Masculino , Memória/efeitos dos fármacos , Proteínas do Tecido Nervoso/metabolismo , Vias Neurais/efeitos dos fármacos , Inibidores da Síntese de Proteínas/farmacologia , Ratos , Ratos Long-Evans , Receptores de AMPA/metabolismo , Membranas Sinápticas/efeitos dos fármacos , Membranas Sinápticas/metabolismo
20.
Food Microbiol ; 62: 196-201, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27889148

RESUMO

Two antimicrobial coatings, namely Sodium octanoate and Auranta FV (a commercial antimicrobial composed of bioflavonoids, citric, malic, lactic, and caprylic acids) were used. These two antimicrobials were surface coated onto the inner polyethylene layer of cold plasma treated polyamide films using beef gelatin as a carrier and coating polymer. This packaging material was then used to vacuum pack beef sub-primal cuts and stored at 4 °C. A control was prepared using the non-coated commercial laminate and the same vacuum packaged sub-primal beef cuts. During storage, microbial and quality assessments were carried out. Sodium octanoate treated packages significantly (p < 0.05) reduced microbial counts for all bacteria tested with an increase of 7 and 14 days, respectively compared to control samples. No significant effect on pH was observed with any treatment. The results suggested that these food grade antimicrobials have the potential to be used in antimicrobial active packaging applications for beef products.


Assuntos
Anti-Infecciosos/química , Embalagem de Alimentos/métodos , Conservação de Alimentos , Plásticos , Animais , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Caprilatos/análise , Caprilatos/química , Bovinos , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Armazenamento de Alimentos/métodos , Gelatina/análise , Gelatina/química , Gases em Plasma/química , Carne Vermelha/microbiologia , Vácuo
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