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1.
Opt Lett ; 49(11): 2942-2945, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38824298

RESUMO

In this Letter, an optically transparent and broadband absorber designed using a multi-objective genetic algorithm (MOGA) is proposed. The absorption of the multilayer lossy frequency selective surface-based absorber is calculated by multilayer absorption equations and equivalent circuit models. To solve the problem of the unbalanced structure absorption bandwidth and thickness, an algorithm is used for optimizing the geometric and sheet resistance parameters of the structure. A multilayer and optically transparent absorber with 90% absorption bandwidth covering a frequency range of 2-18 GHz (S-band to Ku-band) is developed based on the MOGA design method with optical transmittance of 60%. Its total thickness consists of a wavelength of only 0.095, and it has high oblique incidence stability, which makes it useful in the stealth technology and transparent electromagnetic shielding applications.

2.
Sensors (Basel) ; 23(12)2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37420814

RESUMO

A low-profile broadband dual-polarized antenna is investigated for base station applications. It consists of two orthogonal dipoles, fork-shaped feeding lines, an artificial magnetic conductor (AMC), and parasitic strips. By utilizing the Brillouin dispersion diagram, the AMC is designed as the antenna reflector. It has a wide in-phase reflection bandwidth of 54.7% (1.54-2.70 GHz) and a surface-wave bound range of 0-2.65 GHz. This design effectively reduces the antenna profile by over 50% compared to traditional antennas without an AMC. For demonstration, a prototype is fabricated for 2G/3G/LTE base station applications. Good agreement between the simulations and measurements is observed. The measured -10-dB impedance bandwidth of our antenna is 55.4% (1.58-2.79 GHz), with a stable gain of 9.5 dBi and a high isolation of more than 30 dB across the impedance passband. As a result, this antenna is an excellent candidate for miniaturized base station antenna applications.


Assuntos
Utensílios Domésticos , Impedância Elétrica
5.
Int J Mol Med ; 21(6): 825-32, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18506378

RESUMO

It has been suggested that intramyocellular lipids (IMCLs) may serve as biomarkers of insulin resistance and mitochondrial dysfunction. Using a hind-limb mouse model of burn trauma, we tested the hypothesis that severe localized burn trauma involving 5% of the total body surface area causes a local increase in IMCLs in the leg skeletal muscle. We quantified IMCLs from ex vivo intact tissue specimens using High-Resolution Magic Angle Spinning (HRMAS) 1H NMR and characterized the accompanying gene expression patterns in burned versus control skeletal muscle specimens. We also quantified plasma-free fatty acids (FFAs) in burn versus control mice. Our results from HRMAS 1H NMR measurements indicated that IMCL levels were significantly increased in mice exposed to burn trauma. Furthermore, plasma FFA levels were also significantly increased, and gene expression of Glut4, insulin receptor substrate 1 (IRS1), glycolytic genes, and PGC-1beta was downregulated in these mice. Backward stepwise multiple linear regression analysis demonstrated that IMCL levels correlated significantly with FFA levels, which were a significant predictor of IRS1 and PGC-1beta gene expression. We conclude from these findings that IMCLs can serve as metabolic biomarkers in burn trauma and that FFAs and IMCLs may signal altered metabolic gene expression. This signaling may result in the observed burn-induced insulin resistance and skeletal muscle mitochondrial dysfunction. We believe that IMCLs may therefore be useful biomarkers in predicting the therapeutic effectiveness of hypolipidemic agents for patients with severe burns.


Assuntos
Biomarcadores/análise , Queimaduras/metabolismo , Lipídeos/análise , Músculo Esquelético/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Biomarcadores/sangue , Superfície Corporal , Queimaduras/genética , Queimaduras/patologia , Ácidos Graxos não Esterificados/análise , Ácidos Graxos não Esterificados/sangue , Ácidos Graxos não Esterificados/metabolismo , Perfilação da Expressão Gênica , Transportador de Glucose Tipo 4/genética , Transportador de Glucose Tipo 4/metabolismo , Glicólise , Membro Posterior/metabolismo , Membro Posterior/patologia , Humanos , Proteínas Substratos do Receptor de Insulina , Resistência à Insulina , Metabolismo dos Lipídeos , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Camundongos , Mitocôndrias/metabolismo , Modelos Biológicos , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Músculo Esquelético/patologia , Músculo Esquelético/ultraestrutura , Análise de Sequência com Séries de Oligonucleotídeos , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Análise de Regressão , Transativadores/genética , Transativadores/metabolismo , Fatores de Transcrição
6.
Am J Chin Med ; 36(1): 1-24, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18306446

RESUMO

Studies on the treatment of chronic fatigue syndrome (CFS) with acupuncture and moxibustion in China were reviewed. All studies concluded the treatments were effective, with response rates ranging from 78.95% to 100%. However, the qualities of the studies were generally poor, and none of them used a RCT design. The common acupoints/sites used in the treatment of CFS, which may reflect the collective experience of acupuncturists in China based on Traditional Chinese Medicine theories can be used to evaluate the effectiveness of acupuncture for the treatment of CFS in future studies using more scientifically rigorous study designs.


Assuntos
Terapia por Acupuntura , Síndrome de Fadiga Crônica/terapia , Moxibustão , Pontos de Acupuntura , China , Humanos
7.
Int J Mol Med ; 21(2): 201-8, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18204786

RESUMO

Using a mouse model of burn trauma, we tested the hypothesis that severe burn trauma corresponding to 30% of total body surface area (TBSA) causes reduction in adenosine triphosphate (ATP) synthesis in distal skeletal muscle. We employed in vivo 31P nuclear magnetic resonance (NMR) in intact mice to assess the rate of ATP synthesis, and characterized the concomitant gene expression patterns in skeletal muscle in burned (30% TBSA) versus control mice. Our NMR results showed a significantly reduced rate of ATP synthesis and were complemented by genomic results showing downregulation of the ATP synthase mitochondrial F1 F0 complex and PGC-1beta gene expression. Our findings suggest that inflammation and muscle atrophy in burns are due to a reduced ATP synthesis rate that may be regulated upstream by PGC-1beta. These findings implicate mitochondrial dysfunction in distal skeletal muscle following burn injury. That PGC-1beta is a highly inducible factor in most tissues and responds to common calcium and cyclic adenosine monophosphate (cAMP) signaling pathways strongly suggests that it may be possible to develop drugs that can induce PGC-1beta.


Assuntos
Trifosfato de Adenosina/biossíntese , Queimaduras/metabolismo , Regulação para Baixo/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Transativadores/genética , Animais , Superfície Corporal , Queimaduras/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Modelos Biológicos , Fosforilação Oxidativa , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Isótopos de Fósforo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transativadores/metabolismo , Fatores de Transcrição
8.
PLoS Pathog ; 3(9): 1229-39, 2007 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-17941706

RESUMO

Long-term antibiotic use generates pan-resistant super pathogens. Anti-infective compounds that selectively disrupt virulence pathways without affecting cell viability may be used to efficiently combat infections caused by these pathogens. A candidate target pathway is quorum sensing (QS), which many bacterial pathogens use to coordinately regulate virulence determinants. The Pseudomonas aeruginosa MvfR-dependent QS regulatory pathway controls the expression of key virulence genes; and is activated via the extracellular signals 4-hydroxy-2-heptylquinoline (HHQ) and 3,4-dihydroxy-2-heptylquinoline (PQS), whose syntheses depend on anthranilic acid (AA), the primary precursor of 4-hydroxy-2-alkylquinolines (HAQs). Here, we identified halogenated AA analogs that specifically inhibited HAQ biosynthesis and disrupted MvfR-dependent gene expression. These compounds restricted P. aeruginosa systemic dissemination and mortality in mice, without perturbing bacterial viability, and inhibited osmoprotection, a widespread bacterial function. These compounds provide a starting point for the design and development of selective anti-infectives that restrict human P. aeruginosa pathogenesis, and possibly other clinically significant pathogens.


Assuntos
Antibacterianos/farmacologia , Pseudomonas aeruginosa/fisiologia , Percepção de Quorum/efeitos dos fármacos , Percepção de Quorum/fisiologia , Animais , Antibacterianos/uso terapêutico , Sobrevivência Celular/fisiologia , Regulação Bacteriana da Expressão Gênica , Camundongos , Camundongos Endogâmicos , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/genética , Quinolinas/metabolismo , Virulência , Cultura de Vírus , ortoaminobenzoatos/química , ortoaminobenzoatos/metabolismo
9.
Int J Mol Med ; 18(6): 1223-9, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17089030

RESUMO

Burn trauma is a clinical condition accompanied by muscle wasting that severely impedes rehabilitation in burn survivors. Mitochondrial uncoupling protein 3 (UCP3) is uniformly expressed in myoskeletal mitochondria and its expression has been found to increase in other clinical syndromes that, like burn trauma, are associated with muscle wasting (e.g., starvation, fasting, cancer, sepsis). The aim of this study was to explore the effects of burn trauma on UCP3 expression, intramyocellular lipids, and plasma-free fatty acids. Mice were studied at 6 h, 1 d and 3 d after nonlethal hindlimb burn trauma. Intramyocellular lipids in hindlimb skeletal muscle samples collected from burned and normal mice were measured using 1H NMR spectroscopy on a Bruker 14.1 Tesla spectrometer at 4 degrees C. UCP3 mRNA and protein levels were also measured in these samples. Plasma-free fatty acids were measured in burned and normal mice. Local burn trauma was found to result in: 1) upregulation of UCP3 mRNA and protein expression in hindlimb myoskeletal mitochondria by 6 h postburn; 2) increased intramyocellular lipids; and 3) increased plasma-free fatty acids. Our findings show that the increase in UCP3 after burn trauma may be linked to burn-induced alterations in lipid metabolism. Such a link could reveal novel insights into how processes related to energy metabolism are controlled in burn and suggest that induction of UCP3 by burn in skeletal muscle is protective by either activating cellular redox signaling and/or mitochondrial uncoupling.


Assuntos
Queimaduras/metabolismo , Canais Iônicos/metabolismo , Metabolismo dos Lipídeos , Proteínas Mitocondriais/metabolismo , Músculo Esquelético/química , Músculo Esquelético/metabolismo , Ressonância Magnética Nuclear Biomolecular , Animais , Queimaduras/patologia , Temperatura Baixa , Ácidos Graxos/análise , Ácidos Graxos/metabolismo , Membro Posterior/metabolismo , Membro Posterior/patologia , Masculino , Camundongos , Camundongos Endogâmicos , RNA Mensageiro/metabolismo , Fatores de Tempo , Proteína Desacopladora 3
10.
Hypertension ; 48(5): 838-45, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17015784

RESUMO

Case studies and small trials suggest that acupuncture may effectively treat hypertension, but no large randomized trials have been reported. The Stop Hypertension with the Acupuncture Research Program pilot trial enrolled 192 participants with untreated blood pressure (BP) in the range of 140/90 to 179/109 mm Hg. The design of the trial combined rigorous methodology and adherence to principles of traditional Chinese medicine. Participants were weaned off antihypertensives before enrollment and were then randomly assigned to 3 treatments: individualized traditional Chinese acupuncture, standardized acupuncture at preselected points, or invasive sham acupuncture. Participants received < or = 12 acupuncture treatments over 6 to 8 weeks. During the first 10 weeks after random assignment, BP was monitored every 14 days, and antihypertensives were prescribed if BP exceeded 180/110 mm Hg. The mean BP decrease from baseline to 10 weeks, the primary end point, did not differ significantly between participants randomly assigned to active (individualized and standardized) versus sham acupuncture (systolic BP: -3.56 versus -3.84 mm Hg, respectively; 95% CI for the difference: -4.0 to 4.6 mm Hg; P=0.90; diastolic BP: -4.32 versus -2.81 mm Hg, 95% CI for the difference: -3.6 to 0.6 mm Hg; P=0.16). Categorizing participants by age, race, gender, baseline BP, history of antihypertensive use, obesity, or primary traditional Chinese medicine diagnosis did not reveal any subgroups for which the benefits of active acupuncture differed significantly from sham acupuncture. Active acupuncture provided no greater benefit than invasive sham acupuncture in reducing systolic or diastolic BP.


Assuntos
Acupuntura , Hipertensão/prevenção & controle , Adulto , Anti-Hipertensivos/administração & dosagem , Método Duplo-Cego , Humanos , Hipertensão/tratamento farmacológico , Estudos Prospectivos
11.
J Trauma ; 61(2): 280-92, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16917440

RESUMO

BACKGROUND: Severe burn trauma mediates immune dysfunction, infection, and multiple organ dysfunction syndrome. We are investigating the immuno-inflammatory response by characterizing gene expression changes in skeletal muscle after local and distant burn injury. METHODS: Male CD1 mice in three experimental groups, control (unburned), hind limb (local burn), and 30% total body surface area (distant burn), were killed between 6 hours and 10 days postburn; and changes in gastrocnemius muscle global gene expression were assessed using microarrays. RESULTS: The 35 immuno-inflammatory genes are differentially expressed in both models, with an additional 20 and 30 genes specific to distant and local burn, respectively. These genes encode chemokines, oxidative-stress, complement, and defense/immune functions. CONCLUSION: Burn mediates a common systemic response, independent of the site or extent of injury, and also specific responses to local versus distant trauma. A transcriptome profile of genes that initiate and sustain systemic inflammation has been identified.


Assuntos
Queimaduras/imunologia , Expressão Gênica , Músculo Esquelético/imunologia , Síndrome de Resposta Inflamatória Sistêmica/genética , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Animais , Queimaduras/genética , Membro Posterior/lesões , Inflamação/genética , Masculino , Camundongos , Músculo Esquelético/lesões , Análise de Sequência com Séries de Oligonucleotídeos , Distribuição Aleatória
12.
FASEB J ; 19(11): 1431-40, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16126910

RESUMO

Burn trauma triggers hypermetabolism and muscle wasting via increased cellular protein degradation and apoptosis. Proton nuclear magnetic resonance (1H NMR) spectroscopy can detect mobile lipids in vivo. To examine the local effects of burn in skeletal muscle, we performed in vivo 1H NMR on mice 3 days after burn trauma; and ex vivo, high-resolution, magic angle spinning (1)H NMR on intact excised mouse muscle samples before and 1 and 3 days after burn. These samples were then analyzed for apoptotic nuclei using a terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. To confirm our NMR and cell biology results, we used transcriptome analysis to demonstrate that burn trauma alters the expression of genes involved in lipid metabolism and apoptosis. Our results demonstrate that burn injury results in a localized intramyocellular lipid accumulation, which in turn is accompanied by burn-induced apoptosis and mitochondrial dysfunction, as seen by the up-regulation of apoptotic genes and down-regulation of genes that encode lipid oxidation and the peroxisomal proliferator activator receptor gamma coactivator PGC-1beta. Moreover, the increased levels of bisallylic methylene fatty acyl protons (2.8 ppm) and vinyl protons (5.4 ppm), in conjunction with the TUNEL assay results, further suggest that burn trauma results in apoptosis. Together, our results provide new insight into the local physiological changes that occur in skeletal muscle after severe burn trauma.


Assuntos
Apoptose , Queimaduras/metabolismo , Metabolismo dos Lipídeos , Músculo Esquelético/metabolismo , Queimaduras/patologia , Ácidos Graxos/metabolismo , Perfilação da Expressão Gênica , Marcação In Situ das Extremidades Cortadas , Espectroscopia de Ressonância Magnética , Mitocôndrias/fisiologia , Análise de Sequência com Séries de Oligonucleotídeos , Oxirredução
13.
Proc Natl Acad Sci U S A ; 102(15): 5368-73, 2005 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-15809440

RESUMO

Severe burn trauma is generally followed by a catabolic response that leads to muscle wasting and weakness affecting skeletal musculature. Here, we perform whole-genome expression and in vivo NMR spectroscopy studies to define respectively the full set of burn-induced changes in skeletal muscle gene expression and the role of mitochondria in the altered energy expenditure exhibited by burn patients. Our results show 1,136 genes differentially expressed in a mouse hind limb burn model and identify expression pattern changes of genes involved in muscle development, protein degradation and biosynthesis, inflammation, and mitochondrial energy and metabolism. To assess further the role of mitochondria in burn injury, we performed in vivo (31)P NMR spectroscopy on hind limb skeletal muscle, to noninvasively measure high-energy phosphates and the effect of magnetization transfer on inorganic phosphate (P(i)) and phosphocreatine (PCr) resonances during saturation of gammaATP resonance, mediated by the ATP synthesis reactions. Although local burn injury does not alter high-energy phosphates or pH, apart from PCr reduction, it does significantly reduce the rate of ATP synthesis, to further implicate a role for mitochondria in burn trauma. These results, in conjunction with our genomic results showing down-regulation of mitochondrial oxidative phosphorylation and related functions, strongly suggest alterations in mitochondrial-directed energy expenditure reactions, advancing our understanding of skeletal muscle dysfunction suffered by burn injury patients.


Assuntos
Queimaduras/metabolismo , Metabolismo Energético/genética , Perfilação da Expressão Gênica , Mitocôndrias/genética , Mitocôndrias/patologia , Músculo Esquelético/metabolismo , Trifosfato de Adenosina/biossíntese , Trifosfato de Adenosina/metabolismo , Animais , Queimaduras/patologia , Metabolismo dos Carboidratos , Transporte de Elétrons , Gluconeogênese/genética , Membro Posterior , Concentração de Íons de Hidrogênio , Metabolismo dos Lipídeos , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mitocôndrias/metabolismo , Músculo Esquelético/patologia , Fosforilação Oxidativa , Fosfatos/metabolismo , RNA Mensageiro/análise , RNA Mensageiro/genética , Transcrição Gênica/genética , Vigília/genética , Vigília/fisiologia
14.
Proc Natl Acad Sci U S A ; 101(8): 2530-5, 2004 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-14983043

RESUMO

The ubiquitous bacterium Pseudomonas aeruginosa is the quintessential opportunistic pathogen. Certain isolates infect a broad range of host organisms, from plants to humans. The pathogenic promiscuity of particular variants may reflect an increased virulence gene repertoire beyond the core P. aeruginosa genome. We have identified and characterized two P. aeruginosa pathogenicity islands (PAPI-1 and PAPI-2) in the genome of PA14, a highly virulent clinical isolate. The 108-kb PAPI-1 and 11-kb PAPI-2, which are absent from the less virulent reference strain PAO1, exhibit highly modular structures, revealing their complex derivations from a wide array of bacterial species and mobile elements. Most of the genes within these islands that are homologous to known genes occur in other human and plant bacterial pathogens. For example, PAPI-1 carries a complete gene cluster predicted to encode a type IV group B pilus, a well known adhesin absent from strain PAO1. However, >80% of the PAPI-1 DNA sequence is unique, and 75 of its 115 predicted ORF products are unrelated to any known proteins or functional domains. Significantly, many PAPI-1 ORFs also occur in several P. aeruginosa cystic fibrosis isolates. Twenty-three PAPI ORFs were mutated, and 19 were found to be necessary for full plant or animal virulence, with 11 required for both. The large set of "extra" virulence functions encoded by both PAPIs may contribute to the increased promiscuity of highly virulent P. aeruginosa strains, by directing additional pathogenic functions.


Assuntos
Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/patogenicidade , Virulência/genética , Animais , Arabidopsis/microbiologia , Modelos Animais de Doenças , Camundongos , Fases de Leitura Aberta/genética , Doenças das Plantas/microbiologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/microbiologia , Infecções por Pseudomonas/genética , Pseudomonas aeruginosa/isolamento & purificação , Deleção de Sequência
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