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1.
Proc Natl Acad Sci U S A ; 120(9): e2219394120, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36802437

RESUMO

Vocal fatigue is a measurable form of performance fatigue resulting from overuse of the voice and is characterized by negative vocal adaptation. Vocal dose refers to cumulative exposure of the vocal fold tissue to vibration. Professionals with high vocal demands, such as singers and teachers, are especially prone to vocal fatigue. Failure to adjust habits can lead to compensatory lapses in vocal technique and an increased risk of vocal fold injury. Quantifying and recording vocal dose to inform individuals about potential overuse is an important step toward mitigating vocal fatigue. Previous work establishes vocal dosimetry methods, that is, processes to quantify vocal fold vibration dose but with bulky, wired devices that are not amenable to continuous use during natural daily activities; these previously reported systems also provide limited mechanisms for real-time user feedback. This study introduces a soft, wireless, skin-conformal technology that gently mounts on the upper chest to capture vibratory responses associated with vocalization in a manner that is immune to ambient noises. Pairing with a separate, wirelessly linked device supports haptic feedback to the user based on quantitative thresholds in vocal usage. A machine learning-based approach enables precise vocal dosimetry from the recorded data, to support personalized, real-time quantitation and feedback. These systems have strong potential to guide healthy behaviors in vocal use.


Assuntos
Canto , Distúrbios da Voz , Voz , Humanos , Retroalimentação , Distúrbios da Voz/etiologia , Voz/fisiologia , Prega Vocal/fisiologia
2.
Proc Natl Acad Sci U S A ; 118(11)2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33688053

RESUMO

Cattle are natural hosts of the intracellular pathogen Brucella abortus, which inflicts a significant burden on the health and reproduction of these important livestock. The primary routes of infection in field settings have been described, but it is not known how the bovine host shapes the structure of B. abortus populations during infection. We utilized a library of uniquely barcoded B. abortus strains to temporally and spatially quantify population structure during colonization of cattle through a natural route of infection. Introducing 108 bacteria from this barcoded library to the conjunctival mucosa resulted in expected levels of local lymph node colonization at a 1-wk time point. We leveraged variance in strain abundance in the library to demonstrate that only 1 in 10,000 brucellae introduced at the site of infection reached a parotid lymph node. Thus, cattle restrict the overwhelming majority of B. abortus introduced via the ocular conjunctiva at this dose. Individual strains were spatially restricted within the host tissue, and the total B. abortus census was dominated by a small number of distinct strains in each lymph node. These results define a bottleneck that B. abortus must traverse to colonize local lymph nodes from the conjunctival mucosa. The data further support a model in which a small number of spatially isolated granulomas founded by unique strains are present at 1 wk postinfection. These experiments demonstrate the power of barcoded transposon tools to quantify infection bottlenecks and to define pathogen population structure in host tissues.


Assuntos
Brucella abortus/fisiologia , Brucelose/veterinária , Doenças dos Bovinos/microbiologia , Animais , Brucella abortus/genética , Brucella abortus/crescimento & desenvolvimento , Brucella abortus/patogenicidade , Brucelose/microbiologia , Bovinos , Feminino , Linfonodos/microbiologia , Virulência
3.
Bioorg Med Chem ; 90: 117377, 2023 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-37352576

RESUMO

Indoleamine 2,3-dioxygenase (IDO1) is a heme-containing enzyme mainly responsible for the metabolism of tryptophan to kynurenine. To date, the IDO1 inhibitors have been developed intensively for the re-activation of the anticancer immune response. In this report, we designed, and synthesized novel 1,3-dimethyl-6-amino indazole derivatives as IDO1 inhibitors based on the structure of IDO1 active site. We further examined their anticancer activity on hypopharyngeal carcinoma cells (FaDu), squamous cell carcinoma of the oral tongue (YD-15), breast cancer cells (MCF7), and human dental pulp stem cells (HDPSC). Of them, compound N-(4-bromobenzyl)-1,3-dimethyl-1H-indazol-6-amine (7) remarkably suppressed IDO1 expression in a concentration - dependent manner. In addition, 7 was the most potential anticancer compound with inducing apoptosis activity as well as selectively activated extracellular signal-regulated kinases (ERK) in mitogen-activated protein kinase (MAPK) pathways on FaDu cells. Finally, compound 7 suppressed cell mobility in wound healing assay with the reduced expression of matrix metalloproteinase MMP9. Taken together, we believe that 7 is the most promising compound, which may be applied to treatment of hypopharyngeal carcinoma.


Assuntos
Antineoplásicos , Carcinoma , Humanos , Indazóis/química , Antineoplásicos/farmacologia , Antineoplásicos/química , Triptofano , Indolamina-Pirrol 2,3,-Dioxigenase , Inibidores Enzimáticos/química
4.
Forensic Sci Med Pathol ; 19(2): 160-168, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36401783

RESUMO

We report on a process to record the presence and the location of osteocyte nuclei using two nucleic staining dyes, Diamond™ Nucleic Acids Dye (DD) and DAPI (4',6-diamidino-2-phenylindole). Knowledge of the presence and number of osteocytes is key to any success in subsequent DNA profiling. Osteocytes are most numerous cells and thus the main source of DNA in bone samples, which can be preserved for histological analyses. Archived samples are either fixed in formalin or preserved in ethanol prior to embedding in resin. These resin-embedded samples are potentially used as ante mortem reference samples. Cases of a missing person investigation are one example where this type of preserved reference material may be of value. When resin is required for sample preservation it represents a problem for subsequent DNA profiling, if needed as a reference sample in human identification. It is essential therefore to remove the resin prior to DNA analyses as resin is a known inhibitor of DNA profiling. Current methods of resin removal are lengthy and require toxic chemicals. This report describes a simplified process to remove resin and visualise the location of nucleated osteocytes. Eight sections of bone samples at 5-µm thickness were stained with DD and DAPI. A further three samples were processed using a formalin-fixed method and three additional samples treated following an ethanol-preserved method (11 samples for both the formalin-fixed and 11 for the ethanol-preserved with eight in common). The location and number of nuclei could be recorded clearly due to the fluorescence created by the dye binding to DNA. The number of stained nuclei correlated with the mass of DNA isolated from the sections (r = 0.873, p = 1.21 × 10-10). A significant difference between the degradation indices of two groups (p = 8.505 × 10-5) showed that ethanol preservation is a preferred method to yield DNA of the quality needed for subsequent short tandem repeats (STR) profiling. Ten of the 11 samples isolated using the ethanol-preserved process recorded a complete STR profile (30/30 alleles), whereas eight of the formalin-fixed samples generated full profiles, and only one of the 11 samples amplified less than 23 alleles. Both the ethanol-preserved and formalin-fixed methods are an improvement on current methods by removing the need for strong solutes in resin removal, and the method leads to STR profiles from resin-embedded bone samples within 24 h.


Assuntos
DNA , Osteócitos , Humanos , Osteócitos/química , DNA/análise , Formaldeído , Osso e Ossos , Corantes , Etanol , Impressões Digitais de DNA/métodos , Repetições de Microssatélites
5.
Sensors (Basel) ; 21(2)2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33477491

RESUMO

Underwater wireless sensor networks are currently seeing broad research in various applications for human benefits. Large numbers of sensor nodes are being deployed in rivers and oceans to monitor the underwater environment. In the paper, we propose an energy-efficient clustering multi-hop routing protocol (EECMR) which can balance the energy consumption of these nodes and increase their network lifetime. The network area is divided into layers with regard to the depth level. The data sensed by the nodes are transmitted to a sink via a multi-hop routing path. The cluster head is selected according to the depth of the node and its residual energy. To transmit data from the node to the sink, the cluster head aggregates the data packet of all cluster members and then forwards them to the upper layer of the sink node. The simulation results show that EECMR is effective in terms of network lifetime and the nodes' energy consumption.

6.
Int J Mol Sci ; 22(3)2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33540582

RESUMO

Methanol dehydrogenase (Mdh), is a crucial enzyme for utilizing methane and methanol as carbon and energy sources in methylotrophy and synthetic methylotrophy. Engineering of Mdh, especially NAD-dependent Mdh, has thus been actively investigated to enhance methanol conversion. However, its poor catalytic activity and low methanol affinity limit its wider application. In this study, we applied a transcriptional factor-based biosensor for the direct evolution of Mdh from Lysinibacillus xylanilyticus (Lxmdh), which has a relatively high turnover rate and low KM value compared to other wild-type NAD-dependent Mdhs. A random mutant library of Lxmdh was constructed in Escherichia coli and was screened using formaldehyde-detectable biosensors by incubation with low methanol concentrations. Positive clones showing higher fluorescence were selected by fluorescence-activated cell sorting (FACS) system, and their catalytic activities toward methanol were evaluated. The successfully isolated mutants E396V, K318N, and K46E showed high activity, particularly at very low methanol concentrations. In kinetic analysis, mutant E396V, K318N, and K46E had superior methanol conversion efficiency, with 79-, 23-, and 3-fold improvements compared to the wild-type, respectively. These mutant enzymes could thus be useful for engineering synthetic methylotrophy and for enhancing methanol conversion to various useful products.


Assuntos
Oxirredutases do Álcool/genética , Bacillaceae/enzimologia , Mutação , Oxirredutases do Álcool/metabolismo , Bacillaceae/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Técnicas Biossensoriais , Cinética , Metanol/metabolismo
7.
Forensic Sci Med Pathol ; 17(4): 649-659, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34633584

RESUMO

We report on the use of a DNA staining dye to locate and record nucleated osteocytes and other bone-related cells within sections of archived formalin-fixed and paraffin-embedded human tibia from which informative DNA profiles were obtained. Eleven of these archived tibia samples were sectioned at a thickness of 5 µm. Diamond™ Nucleic Acid Dye was applied to the sections and cells within the matrix of the bone fluoresced so that their location and number of cells could be photographed. DNA was isolated from these 11 samples using a standard extraction process and the yields were quantified by real-time PCR. Complete STR profiles were generated from ten bone extracts where low-level inhibition was recorded with an incomplete STR profile obtained from one sample with higher inhibition. The stained image of this sample showed that few cells were present. There was a significant relationship between the number of DD-stained cells and the number of alleles obtained (p < 0.05). Staining cells to determine the prevalence of bone cell nuclei allows a triage of samples prior to any subsequent DNA profiling.


Assuntos
Impressões Digitais de DNA , Repetições de Microssatélites , Osso e Ossos , DNA , Humanos , Reação em Cadeia da Polimerase
8.
Pharm Res ; 37(7): 129, 2020 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-32548664

RESUMO

PURPOSE: Development of a nanoplatform constructed by the PEG-dual drug conjugation for co-delivery of paclitaxel (PTX) and Dihydroartemisinin (DHA) to the tumor. METHODS: PEG was conjugated with PTX and DHA to form PTX-PEG-DHA complex as a nanocarrier. The PTX and DHA were co-encapsulated in PTX-PEG-DHA nanoparticles (PD@PPD NPs) by the emulsion evaporation method. The physicochemical properties of PD@PPD Nps were characterized, including size, zeta potential, and morphology. The drug loading capacity and entrapment efficiency, in vitro drug release at different pH conditions were also evaluated. For in vitro assessment, the effects of the NPs on HT-29 colorectal cancer cells, including intracellular uptake, cytotoxicity, and Bcl-2 protein expression were assessed. The in vivo distribution of the NPs was investigated by labelling the NPs with Cyanine 5.5 fluorophore. Finally, the antitumor efficacy of the NPs was evaluated in HT-29 tumor-bearing mice. RESULTS: The nanoparticles were formed at small size (~114 nm) and narrow distribution. The combination of PTX and DHA in the DHA-PEG-PTX nanosystems (PD@PPD) showed remarkably increased apoptosis in colorectal adenocarcinoma HT-29 cells, as compared to free drug treatment. More importantly, the PD@PPD nanoparticles exhibited significantly higher accumulation in the tumor site owing to the enhanced permeability and retention (EPR) effect, effectively restrained the tumor growth in vivo at low-dose of PTX while reducing the systemic toxicity. CONCLUSIONS: The combination of PTX and DHA in a PEG-conjugated dual-drug co-delivery system can minimize the severe side effect associated with the high-dose of PTX while enhancing the antitumor efficacy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/química , Artemisininas/química , Neoplasias Colorretais/tratamento farmacológico , Nanocápsulas/química , Paclitaxel/química , Polietilenoglicóis/química , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Artemisininas/farmacologia , Permeabilidade da Membrana Celular , Composição de Medicamentos , Liberação Controlada de Fármacos , Corantes Fluorescentes/química , Regulação da Expressão Gênica/efeitos dos fármacos , Células HT29 , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Imagem Óptica , Paclitaxel/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Distribuição Tecidual
9.
Epidemiol Infect ; 148: e180, 2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32364094

RESUMO

Raw milk cheeses are commonly consumed in France and are also a common source of foodborne outbreaks (FBOs). Both an FBO surveillance system and a laboratory-based surveillance system aim to detect Salmonella outbreaks. In early August 2018, five familial FBOs due to Salmonella spp. were reported to a regional health authority. Investigation identified common exposure to a raw goats' milk cheese, from which Salmonella spp. were also isolated, leading to an international product recall. Three weeks later, on 22 August, a national increase in Salmonella Newport ST118 was detected through laboratory surveillance. Concomitantly isolates from the earlier familial clusters were confirmed as S. Newport ST118. Interviews with a selection of the laboratory-identified cases revealed exposure to the same cheese, including exposure to batches not included in the previous recall, leading to an expansion of the recall. The outbreak affected 153 cases, including six cases in Scotland. S. Newport was detected in the cheese and in the milk of one of the producer's goats. The difference in the two alerts generated by this outbreak highlight the timeliness of the FBO system and the precision of the laboratory-based surveillance system. It is also a reminder of the risks associated with raw milk cheeses.


Assuntos
Queijo/microbiologia , Surtos de Doenças , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Infecções por Salmonella/microbiologia , Salmonella/classificação , Animais , Controle de Doenças Transmissíveis , Doenças Transmitidas por Alimentos/epidemiologia , França/epidemiologia , Cabras , Humanos , Infecções por Salmonella/epidemiologia
10.
Sensors (Basel) ; 20(5)2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32121478

RESUMO

Wireless body area networks (WBANs) have become a new paradigm for electronic healthcare applications; for instance, they are used to efficiently monitor patients in real-time. In this paper, an energy-efficient link scheduling (ELS) protocol for cognitive radio body area networks (CRBANs) is proposed, which aims to minimize energy consumption in CRBANs, while achieving higher probabilities of successful transmissions with multiple CRBANs. The proposed ELS transmits packets in the common control channel to control transmission links amongst CRBANs to the gateway and vice versa. The transmissions of CRBANs to the gateway are scheduled at a specific time by the gateway in different data channels, according to the traffic priority of CRBANs. Packet delivery ratio, delay, and energy consumption are evaluated for multiple CRBANs via extensive simulation.


Assuntos
Cognição/fisiologia , Algoritmos , Redes de Comunicação de Computadores , Atenção à Saúde/métodos , Eletrônica/métodos , Humanos , Tecnologia sem Fio
11.
Molecules ; 25(9)2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32354191

RESUMO

The facile synthesis and detailed investigation of a class of highly potent protease inhibitors based on 1,4-naphthoquinones with a dipeptidic recognition motif (HN-l-Phe-l-Leu-OR) in the 2-position and an electron-withdrawing group (EWG) in the 3-position is presented. One of the compound representatives, namely the acid with EWG = CN and with R = H proved to be a highly potent rhodesain inhibitor with nanomolar affinity. The respective benzyl ester (R = Bn) was found to be hydrolyzed by the target enzyme itself yielding the free acid. Detailed kinetic and mass spectrometry studies revealed a reversible covalent binding mode. Theoretical calculations with different density functionals (DFT) as well as wavefunction-based approaches were performed to elucidate the mode of action.


Assuntos
Cisteína Proteases/química , Inibidores de Cisteína Proteinase/síntese química , Naftoquinonas/química , Tripanossomicidas/farmacologia , Catepsina L/química , Cisteína Endopeptidases/química , Inibidores de Cisteína Proteinase/química , Dipeptídeos , Elétrons , Ésteres , Hidrólise , Concentração Inibidora 50 , Cinética , Espectrometria de Massas , Pró-Fármacos/química , Teoria Quântica , Relação Estrutura-Atividade , Trypanosoma brucei brucei/efeitos dos fármacos
12.
J Food Sci Technol ; 57(4): 1320-1330, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32180628

RESUMO

South-East Asian countries produce several million tons annually of Tra catfish (Pangasius hypophthalmus) fillets for export and domestic consumption. However, the processing procedure has not yet been investigated. This study was carried out to analyze the rigor mortis development of the fish and to evaluate the effects of filleting conditions on the quality of the fillets. Compared to pre-rigor fillet processing, post-rigor fillet processing resulted in higher fillet mass yield, less fillet length contraction and reduced exudation loss during chilled storage for both fillets before freezing and fillets after freezing and thawing. The post-rigor fillet processing led to significantly less drip loss after thawing. For fresh fish fillets, pre-rigor processing led to lower cooking loss compared to post-rigor processing. For frozen and thawed fish fillets there was no significant difference in those two parameters. The present research serves as a foundation for further investigations on the modification of processing practices for better fillet quality.

13.
Chemistry ; 25(26): 6533-6541, 2019 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-30820987

RESUMO

Selective chemical modification of proteins plays a pivotal role for the rational design of enzymes with novel and specific functionalities. In this study, a strategic combination of genetic and chemical engineering paves the way for systematic construction of biocatalysts by tuning the product spectrum of a levansucrase from Bacillus megaterium (Bm-LS), which typically produces small levan-like oligosaccharides. The implementation of site-directed mutagenesis followed by a tyrosine-specific modification enabled control of the product synthesis: depending on the position, the modification provoked either enrichment of short oligosaccharides (up to 800 % in some cases) or triggered the formation of high molecular weight polymer. The chemical modification can recover polymerization ability in variants with defective oligosaccharide binding motifs. Molecular dynamic (MD) simulations provided insights into the effect of modifying non-native tyrosine residues on product specificity.


Assuntos
Bacillus megaterium/enzimologia , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/genética , Hexosiltransferases/química , Hexosiltransferases/genética , Oligossacarídeos/metabolismo , Tirosina/química , Bacillus megaterium/química , Bacillus megaterium/genética , Bacillus megaterium/metabolismo , Reação de Cicloadição , Frutanos/química , Frutanos/metabolismo , Glicosídeo Hidrolases/metabolismo , Hexosiltransferases/metabolismo , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Oligossacarídeos/química , Especificidade por Substrato , Tirosina/genética , Tirosina/metabolismo
14.
Epilepsy Behav ; 100(Pt A): 106528, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31654941

RESUMO

This study evaluates the knowledge about psychotic disorders associated with epilepsy among medical practitioners in France. A self-report questionnaire was sent, and responses of 486 participants were collected. Results showed the rate of correct responses being higher among neurologists compared to psychiatrists, respectively 70.6% and 58.3% (p < 10-11). The highest rate of correct responses was found for the participants trained in epileptology (71%), and a regression analysis confirmed that epilepsy-training was the most influential variable. However, we found that knowledge about epileptic psychosis was imprecise among all participants: current classification was not known to most participants (77%), there were false beliefs concerning postictal confusion and psychosis (41%), and both prevalence and duration of postictal psychosis were not well-known. There is the first survey to highlight such gaps of knowledge, and hopefully lead to measures to remedy this, especially specialists such as psychiatrists, neurologists, and epileptologists who may be called upon to treat such patients.


Assuntos
Atitude do Pessoal de Saúde , Epilepsia/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Neurologia/estatística & dados numéricos , Psiquiatria/estatística & dados numéricos , Transtornos Psicóticos/etiologia , Adulto , Confusão , Feminino , França , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Convulsões/psicologia
15.
J Nat Prod ; 82(11): 2941-2952, 2019 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-31626544

RESUMO

Twelve new terpenoids (1-12) were isolated from the stems of Fissistigma polyanthoides, an anti-inflammatory medicinal plant traditionally used in Vietnam. Most of them (1-9) possess a sesquiterpenoid backbone (e.g., guaiane, germacrane, and cadinane) connected to a 2'-O-trans-cinnamoyl)-ß-d-glucopyranose moiety, which is rare in Nature. Among them, compounds 4 (5/8-fused ring) and 6 (spiran [4,5] ring) represent uncommonly rearranged sesquiterpenoids. Compounds 10-12 are a novel monoterpene and two megastigmane derivatives, respectively. The individual structures were elucidated by combining NMR and MS data, and their configuration was established in NOESY and ECD experiments. Compounds 1-9 were also examined for their potential to interact with nuclear factor-kappa B activator protein 1 (NF-κB/AP-1) signaling by using the myelomonocytic reporter cell line THP-1Blue-CD14. Compounds 1-5 showed dose-dependent inhibitory effects [IC50 13.7 µM (1) to 49.0 µM (5)] on lipopolysaccharide-stimulated cells. However, compounds 1 to 4 also negatively affected cell viability in the same concentration range, while compound 5 was less potently cytotoxic.


Assuntos
Annonaceae/química , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacologia , Caules de Planta/química , Terpenos/química , Terpenos/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Lipopolissacarídeos/farmacologia , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Receptor Ativador de Fator Nuclear kappa-B/efeitos dos fármacos , Sesquiterpenos/química , Sesquiterpenos/farmacologia , Vietnã
16.
J Nanosci Nanotechnol ; 19(6): 3252-3262, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30744751

RESUMO

Various Ni catalysts supported on γ-Al2O3 were prepared by a wet impregnation (WI) method and deposition-precipitation (DP) method with different precipitants and applied to CO and CO2 methanation. The prepared catalysts were characterized by various techniques including nitrogen physisorption, X-ray diffraction (XRD), temperature-programmed reduction with H2 (H2-TPR), H2 chemisorption, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Irrespective of kinds of precipitant, the Ni/γ-Al2O3 catalysts prepared with a DP method showed a remarkable enhanced catalytic performance in CO and CO2 methanation compared with the Ni/γ-Al2O3 catalyst prepared with a WI method owing to the higher catalytic active surface area (CASA). In the case of Ni/γ-Al2O3 catalysts prepared with a DP method, the high calcination temperatures are not favorable for the high catalytic activity due to the decreased reduction degree of Ni oxide species and CASA. The reduction degree of Ni oxide species can be increased with reduction temperature. However, the higher reduction temperature above 500 °C is not desirable to achieve the high catalytic activity because of the decreased CASA. The selective CO methanation was also accomplished at lower temperatures over the Ni/γ-Al2O3 catalyst prepared with a DP method than over the Ni/γ-Al2O3 catalyst prepared with a WI method.

17.
Sensors (Basel) ; 19(7)2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-30959849

RESUMO

With the development of wireless communication technology, wireless body area networks (WBANs) have become a fundamental support tool in medical applications. In a real hospital scenario, however, the interference between wireless medical devices and WBANs may cause a high packet drop rate and high latency, which is harmful to patients using healthcare services. Nonetheless, cognitive radio is a promising technology for sharing the precious spectrum, which has high efficiency of the wireless resource. Thus, WBANs with cognitive radio capability are also exploited. We propose a spectrum-aware priority-based link scheduling (SPLS) algorithm for cognitive radio body area networks (CRBANs) in a real hospital scenario. In SPLS, three channels are used: DataCh, EDataCh, and CtrlCh for normal data, emergency data, and control messages, respectively. To avoid collision during data transmission, neighboring CRBANs send messages regarding the channel state with CtrlCh before the scheduling. The CRBANs can share DataCh in the time domain for improving the throughput. The SPLS algorithm allows a CRBAN to access idle channels on the licensed and unlicensed spectrum according to the CRBAN traffic. Our simulation results show that the proposed SPLS outperformed the conventional scheme in terms of packet delivery ratio, system throughput, latency, and energy efficiency.


Assuntos
Algoritmos , Tecnologia sem Fio , Redes de Comunicação de Computadores
18.
Int J Mol Sci ; 21(1)2019 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-31905806

RESUMO

Developing leaves undergo sequential coordinated cell proliferation and cell expansion to determine their final size and shape. Although several important regulators of cell proliferation have been reported, the gene network regulating leaf developmental processes remains unclear. Previously, we showed that ORESARA15 (ORE15) positively regulates the rate and duration of cell proliferation by promoting the expression of direct targets, GROWTH-REGULATING FACTOR (GRF) transcription factors, during leaf growth. In the current study, we examined the spatiotemporal patterns of ORE15 expression and determined that ORE15 expression partially overlapped with AN3/GIF1 and ANT expression along the midvein in the proximal region of the leaf blade in young leaves. Genetic analysis revealed that ORE15 may function synergistically with AN3 to control leaf growth as a positive regulator of cell proliferation. Our molecular and genetic studies are the first to suggest the importance of functional redundancies between ORE15 and AN3, and between AN3 and ANT in cell proliferation regulatory pathway during leaf growth.


Assuntos
Proteínas de Arabidopsis/metabolismo , Proliferação de Células/genética , Folhas de Planta/crescimento & desenvolvimento , Transativadores/metabolismo , Fatores Genéricos de Transcrição/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proliferação de Células/fisiologia , Regulação da Expressão Gênica de Plantas , Folhas de Planta/metabolismo , Transativadores/genética , Fatores de Transcrição/genética , Fatores Genéricos de Transcrição/genética
19.
Angew Chem Int Ed Engl ; 58(11): 3640-3644, 2019 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-30605929

RESUMO

Trypanosomal and leishmanial infections claim tens of thousands of lives each year. The metabolism of these unicellular eukaryotic parasites differs from the human host and their enzymes thus constitute promising drug targets. Tryparedoxin (Tpx) from Trypanosoma brucei is the essential oxidoreductase in the parasite's hydroperoxide-clearance cascade. In vitro and in vivo functional assays show that a small, selective inhibitor efficiently inhibits Tpx. With X-ray crystallography, SAXS, analytical SEC, SEC-MALS, MD simulations, ITC, and NMR spectroscopy, we show how covalent binding of this monofunctional inhibitor leads to Tpx dimerization. Intra- and intermolecular inhibitor-inhibitor, protein-protein, and inhibitor-protein interactions stabilize the dimer. The behavior of this efficient antitrypanosomal molecule thus constitutes an exquisite example of chemically induced dimerization with a small, monovalent ligand that can be exploited for future drug design.


Assuntos
Antiprotozoários/química , Proteínas de Bactérias/química , Inibidores Enzimáticos/química , Oxirredutases/química , Tiorredoxinas/química , Trypanosoma brucei brucei/enzimologia , Animais , Antiprotozoários/metabolismo , Desenho de Fármacos , Inibidores Enzimáticos/metabolismo , Glutationa/análogos & derivados , Glutationa/química , Humanos , Peróxido de Hidrogênio/metabolismo , Simulação de Dinâmica Molecular , Oxirredução , Ligação Proteica , Conformação Proteica , Multimerização Proteica , Espermidina/análogos & derivados , Espermidina/química , Trypanosoma/metabolismo , Trypanosoma/parasitologia
20.
J Org Chem ; 83(17): 10248-10260, 2018 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-30005167

RESUMO

The bioconjugation at tyrosine residues using cyclic diazodicarboxamides, especially 4-substituted 3 H-1,2,4-triazole-3,5(4 H)-dione (PTAD), is a highly enabling synthetic reaction because it can be employed for orthogonal and site-selective (multi)functionalizations of native peptides and proteins. Despite its importance, the underlying mechanisms have not been thoroughly investigated. The reaction can proceed along four distinctive pathways: (i) the SEAr path, (ii) along a pericyclic group transfer pathway (a classical ene reaction), (iii) along a stepwise reaction path, or (iv) along an unusual higher order concerted pericyclic mechanism. The product mixtures obtained from reactions of PTAD with 2,4-unsubstituted phenolate support the SEAr mechanism, but it remains unclear if other mechanisms also take place. In the present work, the various mechanisms are compared using high-level quantum chemistry approaches for the model reaction of 4 H,3 H-1,2,4-triazole-3,5(4 H)-dione (HTAD) with p-cresol and p-cresolate. In a protic solvent (water), the barriers of the SEAr mechanism and the ene reaction are similar but still too high to explain the available experimental observations. This is only possible if the SEAr reaction of cresolate with HTAD is taken into account for which nearly vanishing barriers are computed. This satisfactorily explains measured conversion rates in buffered aqueous solutions and the strong activation effects observed upon addition of bases.

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