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1.
Biomed Microdevices ; 26(4): 41, 2024 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-39312013

RESUMO

Transdermal drug delivery (TDD) has significantly advanced medical practice in recent years due to its ability to prevent the degradation of substances in the gastrointestinal tract and avoid hepatic metabolism. Among different available approaches, microneedle arrays (MNAs) technology represents a fascinating delivery tool for enhancing TDD by penetrating the stratum corneum painless and minimally invasive for delivering antibacterial, antifungal, and antiviral medications. Polymeric MNAs are extensively utilized among many available materials due to their biodegradability, biocompatibility, and low toxicity. Therefore, this review provides a comprehensive discussion of polymeric MNAs, starting with understanding stratum corneum and developing MNA technology. Furthermore, the engineering concepts, fundamental considerations, challenges, and future perspectives of polymeric MNAs in clinical applications are properly outlined, offering a comprehensive and unique overview of polymeric MNAs and their potential for a broad spectrum of clinical applications.


Assuntos
Agulhas , Polímeros , Polímeros/química , Humanos , Sistemas de Liberação de Medicamentos/instrumentação , Animais , Administração Cutânea
2.
Proc Natl Acad Sci U S A ; 118(33)2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34385317

RESUMO

The amino acid and oligopeptide transporter Solute carrier family 15 member A4 (SLC15A4), which resides in lysosomes and is preferentially expressed in immune cells, plays critical roles in the pathogenesis of lupus and colitis in murine models. Toll-like receptor (TLR)7/9- and nucleotide-binding oligomerization domain-containing protein 1 (NOD1)-mediated inflammatory responses require SLC15A4 function for regulating the mechanistic target of rapamycin complex 1 (mTORC1) or transporting L-Ala-γ-D-Glu-meso-diaminopimelic acid, IL-12: interleukin-12 (Tri-DAP), respectively. Here, we further investigated the mechanism of how SLC15A4 directs inflammatory responses. Proximity-dependent biotin identification revealed glycolysis as highly enriched gene ontology terms. Fluxome analyses in macrophages indicated that SLC15A4 loss causes insufficient biotransformation of pyruvate to the tricarboxylic acid cycle, while increasing glutaminolysis to the cycle. Furthermore, SLC15A4 was required for M1-prone metabolic change and inflammatory IL-12 cytokine productions after TLR9 stimulation. SLC15A4 could be in close proximity to AMP-activated protein kinase (AMPK) and mTOR, and SLC15A4 deficiency impaired TLR-mediated AMPK activation. Interestingly, SLC15A4-intact but not SLC15A4-deficient macrophages became resistant to fluctuations in environmental nutrient levels by limiting the use of the glutamine source; thus, SLC15A4 was critical for macrophage's respiratory homeostasis. Our findings reveal a mechanism of metabolic regulation in which an amino acid transporter acts as a gatekeeper that protects immune cells' ability to acquire an M1-prone metabolic phenotype in inflammatory tissues by mitigating metabolic stress.


Assuntos
Regulação da Expressão Gênica/fisiologia , Macrófagos/fisiologia , Proteínas de Membrana Transportadoras/metabolismo , Proteínas do Tecido Nervoso/metabolismo , 4-Cloro-7-nitrobenzofurazano/análogos & derivados , 4-Cloro-7-nitrobenzofurazano/metabolismo , Animais , Diferenciação Celular , Linhagem Celular , Células Dendríticas/metabolismo , Desoxiglucose/análogos & derivados , Desoxiglucose/metabolismo , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/fisiologia , Regulação da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Humanos , Macrófagos/efeitos dos fármacos , Proteínas de Membrana Transportadoras/genética , Camundongos , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Oligodesoxirribonucleotídeos/farmacologia
3.
Anim Biotechnol ; 34(6): 1909-1918, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35404767

RESUMO

Interspecies somatic cell nuclear transfer (iSCNT) has an immense potential to rescue endangered animals and extinct species like mammoths. In this study, we successfully established an Asian elephant's fibroblast cell lines from ear tissues, performed iSCNT with porcine oocytes and evaluated the in vitro and in vivo development of reconstructed embryos. A total of 7780 elephant-pig iSCNT embryos were successfully reconstructed and showed in vitro development with cleavage rate, 4-cell, 8-cell and blastocyst rate of 73.01, 30.48, 5.64, and 4.73%, respectively. The total number of elephant-pig blastocyte cells and diameter of hatched blastocyte was 38.67 and 252.75 µm, respectively. Next, we designed species-specific markers targeting EDNRB, AGRP and TYR genes to verify the genome of reconstructed embryos with donor nucleus/species. The results indicated that 53.2, 60.8, and 60.8% of reconstructed embryos (n = 235) contained elephant genome at 1-cell, 2-cell and 4-cell stages, respectively. However, the percentages decreased to 32.3 and 32.7% at 8-cell and blastocyst stages, respectively. Furthermore, we also evaluated the in vivo development of elephant-pig iSCNT cloned embryos and transferred 2260 reconstructed embryos into two surrogate gilts that successfully became pregnant and a total of 11 (1 and 10) fetuses were surgically recovered after 17 and 19 days of gestation, respectively. The crown-rump length and width of elephant-pig cloned fetuses were smaller than the control group. Unfortunately, none of these fetuses contained elephant genomes, which suggested that elephant embryos failed to develop in vivo. In conclusion, we successfully obtained elephant-pig reconstructed embryos for the first time and these embryos are able to develop to blastocyst, but the in vivo developmental failure needs further investigated.


Assuntos
Clonagem de Organismos , Elefantes , Gravidez , Animais , Suínos , Feminino , Clonagem de Organismos/métodos , Elefantes/genética , Técnicas de Transferência Nuclear/veterinária , Oócitos/metabolismo , Blastocisto , Sus scrofa , Desenvolvimento Embrionário , Embrião de Mamíferos
4.
Int Immunol ; 33(7): 399-406, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-33560415

RESUMO

Solute carrier family 15 member 4 (SLC15A4) is an endolysosome-resident amino acid transporter that regulates innate immune responses, and is genetically associated with inflammatory diseases such as systemic lupus erythematosus (SLE) and colitis. SLC15A4-deficient mice showed the amelioration of symptoms of these model diseases, and thus SLC15A4 is a promising therapeutic target of SLE and colitis. For developing a SLC15A4-based therapeutic strategy, understanding human SLC15A4's properties is essential. Here, we characterized human SLC15A4 and demonstrated that human SLC15A4 possessed pH- and temperature-dependent activity for the transportation of dipeptides or tripeptides. Human SLC15A4 localized in LAMP1+ compartments and constitutively associated with Raptor and LAMTORs. We also investigated SLC15A4's role in inflammatory responses using the human plasmacytoid dendritic cell line, CAL-1. Knock down (KD) of the SLC15A4 gene in CAL-1 (SLC15A4-KD CAL-1) impaired Toll-like receptor (TLR) 7/8 or TLR9-triggered type I interferon (IFN-I) production and mTORC1 activity, indicating that human SLC15A4 is critical for TLR7/8/9-mediated inflammatory signaling. We also examined SLC15A4's role in the autophagy response since SLC15A4 loss caused the decrease of mTORC1 activity, which greatly influences autophagy. We found that SLC15A4 was not required for autophagy induction, but was critical for autophagy sustainability. Notably, SLC15A4-KD CAL-1 severely decreased mitochondrial membrane potential in starvation conditions. Our findings revealed that SLC15A4 plays a key role in mitochondrial integrity in human cells, which might benefit immune cells in fulfilling their functions in an inflammatory milieu.


Assuntos
Interferon Tipo I/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Mitocôndrias/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptores Toll-Like/metabolismo , Animais , Linhagem Celular , Colite/metabolismo , Células Dendríticas/metabolismo , Células HEK293 , Humanos , Imunidade Inata/fisiologia , Inflamação/metabolismo , Lúpus Eritematoso Sistêmico/metabolismo , Lisossomos/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Transdução de Sinais/fisiologia
5.
Bull Environ Contam Toxicol ; 107(3): 475-486, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33760936

RESUMO

Unsubstituted and methylated polycyclic aromatic hydrocarbons (22 PAHs and 17 Me-PAHs) were examined in surface sediments collected from the Red River and four inner-city rivers of Hanoi City, Vietnam. Concentrations of total PAHs and Me-PAHs ranged from 52 to 920 (median 710) and from 70 to 2600 (median 1000) ng/g dry weight in samples of dry and wet seasons, respectively. Significant correlation was observed between total PAHs and organic carbon contents (Spearman's ρ = 0.782; p < 0.05). PAHs were more abundant than Me-PAHs in all samples and dominated by 4-6 ring compounds. The most predominant PAHs were benzo[ghi]perylene, benzo[b/j]fluoranthene, chrysene, pyrene, fluoranthene, and phenanthrene. Methylated derivatives of naphthalene, phenanthrene, anthracene, and benz[a]anthracene were frequently detected. The patterns of PAHs indicated principal pyrogenic sources (notably gasoline exhaust) in this highly urbanized area. The occurrence of several PAHs were occasionally associated with adverse effects on benthic organisms of the inner-city rivers.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Monitoramento Ambiental , Sedimentos Geológicos , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de Risco , Vietnã , Poluentes Químicos da Água/análise
6.
J Asian Nat Prod Res ; 21(6): 507-515, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29597834

RESUMO

Four new compounds N-salicyl-3-hydroxyanthranilic acid methyl ester (1), N-(2'-dehydroxysalicyl)-3-hydroxyanthranilic acid methyl ester (2), methyl-4-ß-D-allopyranosyl-ferulate (3), and methyl-4-ß-D-gulopyranosyl-cinnamate (4), along with six known compounds (5-10), were isolated from the roots of Aconitum carmichelii Debx. Their structures were elucidated on the basis of spectral data analysis, including 1D, 2D-NMR, and HR-ESI-MS. Compounds 1 and 2 showed the inhibition of nitric oxide (NO) production with IC50 values of 9.13 and 19.94 µM, respectively.


Assuntos
Aconitum/química , Cinamatos/química , Raízes de Plantas/química , ortoaminobenzoatos/química , Animais , Cinamatos/farmacologia , Medicamentos de Ervas Chinesas , Glucosídeos/química , Glucosídeos/farmacologia , Espectroscopia de Ressonância Magnética , Camundongos , Estrutura Molecular , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese , Células RAW 264.7 , Espectrometria de Massas por Ionização por Electrospray , ortoaminobenzoatos/farmacologia
7.
J Cell Biochem ; 117(3): 659-70, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26291957

RESUMO

Eurycoma longifolia is an herbal medicinal plant popularly used in Southeast Asian countries. In the present study, we show that 7-methoxy-(9H-ß-carbolin-1-il)-(E)-1-propenoic acid (7-MCPA), a ß-carboline alkaloid isolated from E. longifolia, exerted anti-inflammatory effects by activating the nuclear factor-E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. 7-MCPA inhibited lipopolysaccharide (LPS)-induced production of nitric oxide (NO), prostaglandin E2 (PGE2 ), and interleukin-6 (IL-6) in RAW264.7 cells and rescued C57BL/6 mice from LPS-induced lethality in vivo. LPS-induced expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and IL-6 was also significantly suppressed by treatment of 7-MCPA in RAW264.7 cells. 7-MCPA induced nuclear translocation of Nrf2 and increased transcription of its target genes, such as HO-1. Treating RAW264.7 cells with 7-MCPA increased the intracellular level of reactive oxygen species (ROS) and the phosphorylation level of p38 mitogen-activated protein kinase (MAPK); however, co-treatment with the antioxidant N-acetyl-cysteine (NAC) blocked 7-MCPA-induced p38 MAPK phosphorylation. Moreover, NAC or SB203580 (p38 MAPK inhibitor) blocked 7-MCPA-induced nuclear translocation of Nrf2, suggesting that 7-MCPA activated Nrf2 via a ROS-dependent p38 pathway. 7-MCPA induced HO-1 protein and mRNA expression and knockdown of Nrf2 with siRNA or SB203580 blocked 7-MCPA-mediated induction of HO-1 expression. Inhibiting Nrf2 or HO-1 abrogated the anti-inflammatory effects of 7-MCPA in LPS-stimulated RAW264.7 cells. We also demonstrated that 7-MCPA suppressed LPS-induced nuclear factor κB (NF-κB) activation. These results provide the first evidence that 7-MCPA exerts its anti-inflammatory effect by modulating the Nrf2 and NF-κB pathways and may be a potential Nrf2 activator to prevent or treat inflammatory diseases.


Assuntos
Acrilatos/farmacologia , Anti-Inflamatórios/farmacologia , Carbolinas/farmacologia , Heme Oxigenase-1/metabolismo , Proteínas de Membrana/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Extratos Vegetais/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Avaliação Pré-Clínica de Medicamentos , Eurycoma/química , Interleucina-6/metabolismo , Lipopolissacarídeos/farmacologia , Sistema de Sinalização das MAP Quinases , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Células RAW 264.7 , Transdução de Sinais/imunologia
8.
Pharm Biol ; 53(10): 1549-54, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25858626

RESUMO

CONTEXT: Caesalpinia sappan Linn. (Leguminosae) has been used in folk medicines for the treatment of many diseases. The heartwood of this plant contains various phenolic components with interesting biological applications; however, the chemical and biological potentials of the seed of this plant have not been fully explored. OBJECTIVE: This study identified the cytotoxic activity of compounds from the seeds of C. sappan. MATERIALS AND METHODS: The methanol extract of the seed of C. sappan was suspended in H2O and then partitioned with CH2Cl2, EtOAc, and n-BuOH, successively. Diterpenoid compounds were isolated from the CH2Cl2-soluble fraction by silica gel column chromatography methods using organic solvents. The compound structures were determined by detailed analysis of NMR and MS spectral data. Cytotoxic activity was measured using a modified MTT assay against HL-60, HeLa, MCF-7, and LLC cancer cells. The activation of caspase-3 enzyme and western blotting assay were performed to confirm inhibitory mechanism of active compound. RESULTS: Five cassane-type diterpenoids were isolated and identified as phanginin I (1), phaginin A (2), phanginin D (3), phanginin H (4), and phanginin J (5). Compounds 1-4 showed effective inhibition against HL-60 cells with the IC50 values of 16.4 ± 1.5, 19.2 ± 2.0, 11.7 ± 1.6, and 22.5 ± 5.1 µM. Compounds 1-3 exhibited cytotoxic activity against HeLa cells with the IC50 values of 28.1 ± 3.6, 37.2 ± 3.4, and 22.7 ± 2.8 µM. Treatment of HL-60 cell lines with various concentrations of 3 (0-30 µM) resulted in the growth inhibition and induction of apoptosis. CONCLUSION: These findings demonstrate that compound 3 (phanginin D) is one of the main active components of the seed of C. sappan activating caspases-3 which contribute to apoptotic cell death.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Caesalpinia , Citotoxinas/farmacologia , Extratos Vegetais/farmacologia , Sementes , Animais , Antineoplásicos Fitogênicos/isolamento & purificação , Carcinoma Pulmonar de Lewis , Caspase 3/metabolismo , Citotoxinas/isolamento & purificação , Células HL-60 , Células HeLa , Humanos , Células MCF-7 , Extratos Vegetais/isolamento & purificação , Vietnã
9.
Pharm Biol ; 52(1): 74-7, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24044731

RESUMO

CONTEXT: A methanol extract of Cyperus rotundus L. (Cyperaceae) rhizomes showed inhibitory activity against α-glucosidase and α-amylase, two enzymes involve in carbohydrate digestion. OBJECTIVE: Identification of compounds from C. rotundus rhizomes responsible for the inhibition of α-glucosidase and α-amylase. MATERIALS AND METHODS: Compounds were identified by a phytochemical investigation using combined chromatographic and spectroscopic methods. α-glucosidase and α-amylase inhibitory activities were evaluated by in vitro enzyme inhibition assays. RESULTS: A new (2RS,3SR)-3,4',5,6,7,8-hexahydroxyflavane (1), together with three known stilbene dimers cassigarol E (2), scirpusin A (3) and B (4) were isolated. Compound 2 inhibited both α-glucosidase and α-amylase activities while the flavane 1 only showed effect on α-amylase, and compounds 3 and 4 were active on α-glucosidase. All four compounds showed significant 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. DISCUSSION: The inhibitory activities against α-amylase and α-glucosidase of the C. rotundus rhizomes were reported for the first time. Stilbene dimers are considered as potent inhibitors of α-glucosidase and promising antihyperglycemic agents. CONCLUSION: The isolated compounds may contribute to the antidiabetic property of C. rotundus.


Assuntos
Cyperus/química , Inibidores de Glicosídeo Hidrolases , Extratos Vegetais/farmacologia , alfa-Amilases/antagonistas & inibidores , Compostos de Bifenilo/química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/isolamento & purificação , Sequestradores de Radicais Livres/farmacologia , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/farmacologia , Picratos/química , Extratos Vegetais/química , Rizoma
10.
J Microbiol Biotechnol ; 34(1): 56-64, 2024 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-37940179

RESUMO

The widespread application of triazole fungicides (TFs) in agricultural practices can result in the considerable accumulation of active compound residues in the soil and a subsequent negative impact on the soil microbiota and crop health. In this study, we isolated three TF-degrading bacterial strains from contaminated agricultural soils and identified them as Klebsiella sp., Pseudomonas sp., and Citrobacter sp. based on analysis of morphological characteristics and 16S rRNA gene sequences. The strains used three common TFs, namely hexaconazole, difenoconazole, and propiconazole, as their only sources of carbon and energy for growth in a liquid mineral salt medium, with high concentrations (~ 500 mg/l) of each TF. In addition to the ability to degrade fungicides, the isolates also exhibited plant growth-promoting characteristics, such as nitrogen fixation, indole acetic acid production, phosphate dissolution, and cellulose degradation. The synergistic combination of three bacterial isolates significantly improved plant growth and development with an increased survival rate (57%), and achieved TF degradation ranging from 85.83 to 96.59% at a concentration of approximately 50 mg/kg of each TF within 45 days in the soil-plant system. Based on these findings, the three strains and their microbial consortium show promise for application in biofertilizers, to improve soil health and facilitate optimal plant growth.


Assuntos
Fungicidas Industriais , Poluentes do Solo , Fungicidas Industriais/farmacologia , RNA Ribossômico 16S/genética , Bactérias , Solo/química , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Triazóis/farmacologia , Triazóis/metabolismo , Microbiologia do Solo
11.
PLoS One ; 19(6): e0304983, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38829849

RESUMO

This paper introduces a two-element antenna array with dual-sense circular polarization, wideband operation, and high isolation characteristics. The antenna consists of two conventional truncated corner patches and an extra layer of metasurface (MS) located above the radiating patches. The overall dimensions of the proposed antenna are 0.92 λ0 × 0.73 λ0 × 0.05 λ0 and the element spacings are 0.02 λ0 and 0.39 λ0 with respect to edge-to-edge and center-to-center spacings. For validation, measurements on a fabricated antenna prototype are carried out. The measured data demonstrate that the presented MS-based antenna has a wide operating bandwidth of 14.5% with high isolation of better than 26 dB. The excellent performance could be concluded from the results of the investigation, which indicates that the proposed MS-based antenna could be a good candidate for multiple-input multiple-output (MIMO) and full-duplex applications.


Assuntos
Desenho de Equipamento , Tecnologia sem Fio/instrumentação
12.
Environ Sci Pollut Res Int ; 31(15): 22362-22379, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38409380

RESUMO

Urban rivers are significantly impacted by anthropogenic pressure. This study presents the updated assessment of the concentrations of 11 metals and other variables (pH, total organic carbon (TOC) and nutrients (total nitrogen, total phosphorus, and total silica)) in the sediments of four urban rivers in inner Hanoi city, Vietnam, during the period 2020-2022. The mean concentrations of Fe, Zn, As, and Cr were higher than the permissible values of the Vietnam National technical regulation on the surface sediment quality. Moreover, Zn and Cr were at the severe effect level of the US EPA guidelines for sediment quality. The calculation of pollution indices (Igeo and EF) demonstrated that Mn, Ni, and Fe were from natural sources whereas other metals were from both anthropogenic and natural sources. The ecological risk index revealed that metals in Hanoi riverine sediments were classified at considerable ecological risk. High values of metals, TOC, and nutrients in the sediments of these urban rivers mostly originate from the accumulation of untreated urban wastewater that is enhanced by low river discharge. Our results may provide scientific base for better management decisions to ensure environmental protection and sustainable development of Hanoi city.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Metais Pesados/análise , Vietnã , Rios , Poluentes Químicos da Água/análise , Sedimentos Geológicos , Monitoramento Ambiental/métodos , Ásia , Medição de Risco , China
13.
J Anal Methods Chem ; 2024: 5652559, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39045342

RESUMO

Vodka constitutes a significant sector of Vietnam's alcohol industry, including both domestic and imported varieties. However, this diversity faces challenges from illegal imports and adulterated products, threatening consumer health and brand integrity. This study employs Fourier transform infrared spectroscopy (FTIR) and inductively coupled plasma mass spectrometry (ICP-MS) to analyze 300 vodka samples from five brands collected across Hanoi. Significant variations were found in elemental compositions, with sodium concentrations ranging from 205.67 µg/L to 1269.24 µg/L and magnesium levels from 65.57 µg/L to 1453.34 µg/L. Principal Component Analysis (PCA) of the FTIR and ICP-MS data effectively differentiated the samples, with the first two principal components explaining 84.78% and 73.02% of the total variance, respectively. The PCA plots revealed distinct chemical profiles, notably isolating Rocket Vodka. These findings enhance food safety enforcement, protect consumer rights, and preserve brand reputations. The study underscores the importance of advanced analytical tools in combating beverage adulteration, ensuring public health, and maintaining market integrity, offering a replicable model for similar research in other regions.

14.
PLoS One ; 19(7): e0304414, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38968233

RESUMO

This paper proposes a compact design of dual-sense circularly polarized (CP) antenna for simultaneous transmit (Tx) and receive (Rx) communication systems. The primary radiating aperture of the proposed antenna is a 2 × 2 unit-cell metasurface (MS). The MS is excited by the asymmetric patch in the center, which acts as the CP source of the whole antenna structure. By properly tuning the feeding positions, dual-sense CP with high isolation can be achieved. For verification, an antenna prototype with compact dimensions of 0.36λ × 0.36λ × 0.02λ (λ is the free-space wavelength at the center operating frequency) is fabricated and measured. The measured operating bandwidth is 1.6% (2.45-2.49 GHz), in which the reflection and transmission coefficients are less than-10 dB and the axial ratio is lower than 3 dB. Within this band, the maximum isolation value is 39 dB, and the peak gain is 5.7 dBi.


Assuntos
Desenho de Equipamento , Tecnologia sem Fio , Tecnologia sem Fio/instrumentação
15.
Micromachines (Basel) ; 15(8)2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39203702

RESUMO

This paper introduces the design of a circularly polarized metasurface-based antenna array for C-band satellite applications that owns broadband operation and high gain characteristics. The single radiating element comprises a Y-shape patch and an above-placed 2 × 2 unit-cell metasurface. Further improvement in operating bandwidth and broadside gain is achieved by arranging four single elements in a 2 × 2 configuration and a sequential-phase feed network. A prototype has been fabricated and measured to validate the feasibility of the proposed antenna array. The measured operating bandwidth is 20% (4.50-5.50 GHz), which is an overlap between a -10 dB impedance bandwidth of 29.8% (4.50-5.99 GHz) and a 3 dB axial ratio bandwidth of 20% (4.50-5.50 GHz). Across this operating band, the peak broadside gain is 10.5 dBi. Compared with the recently published studies, the proposed array is a prominent design for producing a wide operating bandwidth and relatively high gains while maintaining the overall compact dimensions.

16.
J Anal Methods Chem ; 2024: 1329212, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38505133

RESUMO

Sausage is a convenient food that is widely consumed in the world and in Vietnam. Due to the rapid development of this product, the authenticity of many famous brands has faded by the rise of adulteration. Therefore, in this study, principal component analysis (PCA) was combined with chemical analysis to identify 6 sausage brands. Sausage samples were dried and then ground to a fine powder for both instrumental analyses of attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and inductively coupled plasma-mass spectrometry (ICP-MS). Dried measurements of ATR-FTIR was performed directly on the ZnSe crystal, while elemental data were obtained through microwave digestion before the ICP-MS analysis. Principal component analysis (PCA) within the framework software of XLSTAT and STATISTICA 12 was performed on the spectroscopy and elemental dataset of sausage samples. PCA visualized the distinction of 6 sausage brands on both datasets of ATR-FTIR and ICP-MS. The classification on the spectroscopy profile showed that although more than 90% variation of the dataset was explained on the first two PCs, the difference between several brands was not detected as the distribution of data overlapped with one another. The PCA observation of the elemental composition on PC1 and PC3 has separated the sausage brands into 6 distinctive groups. Besides, several key elements contributed to the brands' identification have been detected, and the most distinctive elements are Na, K, Ca, and Ba. PCA visualization showed the feasibility of the classification of sausage samples from different brands when combined with the results of FT-IR and ICP-MS methods. The experiment was able to differentiate the sausages from the 5 brands using multivariate statistics.

17.
Food Sci Nutr ; 11(10): 6509-6521, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37823137

RESUMO

Optimization and validation for simultaneous quantitation of four aflatoxins B1, B2, G1, and G2 in peanuts and raisins were performed on ultra-performance liquid chromatography in a combination of fluorescence detector, without derivatization. The advantages were short analysis time, simple sample handling, and reduced solvent consumption. Instrument detection limits of AFB1, AFB2, AFG1, and AFG2 were 0.07, 0.01, 0.1, and 0.008 µg/kg, respectively, lower than those obtained by LCMSMS and HPLC-FLD with derivatization. Two solvent mixtures were chosen for two different matrices whose matrix effect was not negligible (2.81%-8.04% for peanuts and 5.63%-11.43% for raisins). The linear ranges were from 0.2 to 20 µg/L for AFB1 and AFG1 and from 0.05 to 5 µg/L for AFB2 and AFG2. The limits of detection and quantification were 0.025-0.1 and 0.075-0.3 µg/kg for peanuts and raisins, respectively. Recoveries at three other concentrations from 0.75 to 125 µg/kg of total aflatoxins were obtained between 76.5% and 99.8% (with RSD < 6%) following the SANTE 11312/2021. Validation parameters complied with the requirements of ISO/IEC 17025:2017. The extracts and the sample could be stabilized at 4°C and 20°C for 24 h and at -20°C for up to 21 days, respectively. Thus, the study can be used as a standard method for the analysis of Aflatoxins (AFs) in peanut and raisin matrices. Investigation of 350 peanut samples collected at Markets in the central districts of HCM city showed that 28.6% were contaminated with AFB1 from 0.31 up to 554 µg/kg; 13.4% contained AFB2, and 5.7% of AFG1 in the range of 0.4-53 µg/kg and 0.4-9.57 µg/kg, respectively; AFG2 (about 0.6%) was detected from 0.45 to 0.75 µg/kg. Meanwhile, 12.8% exceeded the total aflatoxins limit, and 13.4% exceeded the AFB1 limit. AFs were almost not found in the 350 raisin samples.

18.
Braz J Microbiol ; 54(4): 2617-2626, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37792269

RESUMO

Plant diseases caused by phytopathogenic fungi are one of the leading factors affecting crop loss. In the present study, sixty-one Streptomyces strains were screened for their antifungal activity against relevant wide range fungal pathogens prominent in Vietnam, namely Lasiodiplodia theobromae, Fusarium fujikuroi, and Scopulariopsis gossypii. Endophytic strain RC2 was the most effective strain in the mycelial inhibition of the tested fungi. Based on phenotypic characteristics, 16S rDNA gene analysis, and genomic analysis, strain RC2 belonged to Streptomyces albus. An ethyl acetate extract of S. albus RC2 led to the strong growth inhibition of S. gossypii Co1 and F. fujikuroi L3, but not L. theobromae N13. The crude extract also suppressed the spore germination of S. gossypii Co1 and F. fujikuroi L3 to 92.4 ± 3.2% and 87.4% ± 1.9%, respectively. In addition, the RC2 extract displayed potent and broad-spectrum antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, and the phytopathogenic bacteria Ralstonia solanacearum and Xanthomonas oryzae. The genome of strain RC2 was sequenced and revealed the presence of 15 biosynthetic gene clusters (BGCs) with similarities ≥ 45% to reference BGCs available in the antiSMASH database. The UPLC-HRMS analysis led to the identification of 8 other secondary metabolites, which have not been reported in S. albus. The present study indicated that RC2 could be a potent biocontrol agent against phytopathogenic fungi. Further attention should be paid to antifungal metabolites without functional annotation, development of product prototypes, and greenhouse experiments to demonstrate effective control of the plant diseases.


Assuntos
Antifúngicos , Streptomyces , Antifúngicos/farmacologia , Genômica , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologia
19.
Mar Pollut Bull ; 192: 115078, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37210986

RESUMO

Contamination of aquaculture products by pathogenic organisms is a major concern in areas where this activity is of high economic importance. The abundances of total coliforms (TC), Escherichia coli (EC) and faecal streptococci (FS) (in CFU.100 mL-1) in seawater in the Red River coastal aquaculture zone were determined. The results showed TC numbers (200 to 9100; average 1822), EC (<100 to 3400; average 469) and FS (<100 to 2100; average 384), of which TC exceeded the allowable threshold of the Vietnam regulation for coastal aquaculture water. TC and EC numbers in 4 wastewater types (domestic, livestock farming sewage, agricultural runoff, and mixed sewage canals) were investigated and revealed the importance of point sources of faecal contamination in seawater. These results underline the need to reduce the release of untreated wastewater and to put into place seawater microbial quality monitoring in areas where the development of sustainable aquaculture is an objective.


Assuntos
Esgotos , Águas Residuárias , Vietnã , Escherichia coli , Aquicultura , Fezes , Bactérias Gram-Negativas , Monitoramento Ambiental/métodos , Microbiologia da Água
20.
J Anal Methods Chem ; 2023: 1465773, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37928250

RESUMO

Fingerprinting techniques, which utilize the unique chemical and physical properties of food samples, have emerged as a promising approach for food authentication and traceability. Recent studies have demonstrated significant advancements in food authentication through the use of fingerprinting methods, such as multivariate statistical analysis techniques applied to trace elements and isotope ratios. However, further research is required to optimize these methods and ensure their validity and reliability in real-world applications. In this study, the inductively coupled plasma mass spectrometry (ICP-MS) analytical method was employed to determine the content of 21 elements in 300 cashew nut (Anacardium occidentale L.) samples from 5 brands. Multivariate statistical methods, such as principal components analysis (PCA), were employed to analyze the data obtained and establish the provenance of the cashew nuts. While cashew nuts are widely marketed in many countries, no universal method has been utilized to differentiate the origin of these nuts. Our study represents the initial step in identifying the geographical origin of commercial cashew nuts marketed in Vietnam. The analysis showed significant differences in the means of 21 of the 40 analyzed elements among the cashew nut samples from the 5 brands, including 7Li, 11B, 24Mg, 27Al, 44Ca, 48Ti, 51V, 52Cr, 55Mn, 57Fe, 60Ni, 63Cu, 66Zn, 93Nb, 98Mo, 111Cd, 115In, 121Sb, 138Ba, 208Pb, and 209Bi. The PCA analysis indicated that the cashew nut samples can be accurately classified according to their original locations. This research serves as a prerequisite for future studies involving the combination of elemental composition analysis with statistical classification methods for the accurate establishment of cashew nut provenance, which involves the identification of key markers for the original discrimination of cashew nuts.

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