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1.
Chaos ; 33(7)2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37486665

RESUMO

Mobile intrinsic localized modes (ILMs) in balanced nonlinear capacitive-inductive cyclic transmission lines are studied by experiment, using a spatiotemporal driver under damped steady-state conditions. Without nonlinear balance, the experimentally observed resonance between the traveling ILM and normal modes of the nonlinear transmission line generates lattice drag via the production of a lattice backwave. In our experimental study of a balanced running ILM in a steady state, it is observed that the fundamental resonance can be removed over extended, well-defined driving frequency intervals and strongly suppressed over the complete ILM driving frequency range. Because both of these nonlinear capacitive and inductive elements display hysteresis our observation demonstrates that the experimental system, which is only partially self-dual, is surprisingly tolerant, regarding the precision necessary to eliminate the ILM backwave. It appears that simply balancing the cell dual nonlinearities makes the ILM envelope shape essentially the same at the two locations in the cell, so that the effective lattice discreteness seen by the ILM nearly vanishes.

2.
Nature ; 530(7591): 453-6, 2016 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-26911781

RESUMO

In recent years, millisecond-duration radio signals originating in distant galaxies appear to have been discovered in the so-called fast radio bursts. These signals are dispersed according to a precise physical law and this dispersion is a key observable quantity, which, in tandem with a redshift measurement, can be used for fundamental physical investigations. Every fast radio burst has a dispersion measurement, but none before now have had a redshift measurement, because of the difficulty in pinpointing their celestial coordinates. Here we report the discovery of a fast radio burst and the identification of a fading radio transient lasting ~6 days after the event, which we use to identify the host galaxy; we measure the galaxy's redshift to be z = 0.492 ± 0.008. The dispersion measure and redshift, in combination, provide a direct measurement of the cosmic density of ionized baryons in the intergalactic medium of ΩIGM = 4.9 ± 1.3 per cent, in agreement with the expectation from the Wilkinson Microwave Anisotropy Probe, and including all of the so-called 'missing baryons'. The ~6-day radio transient is largely consistent with the radio afterglow of a short γ-ray burst, and its existence and timescale do not support progenitor models such as giant pulses from pulsars, and supernovae. This contrasts with the interpretation of another recently discovered fast radio burst, suggesting that there are at least two classes of bursts.

3.
Chaos ; 32(3): 033118, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35364854

RESUMO

In this experimental study of the nonlinear loss mechanism between traveling localized excitation and the underlying extended normal mode spectrum for a 1D lattice, three types of cyclic, electric, nonlinear transmission lines (NLTLs) are used. They are nonlinear capacitive, inductive, and capacitive+inductive NLTLs. To maintain a robust, steady-state traveling intrinsic localized mode (ILM), a traveling wave driver is used. The ILM loses energy because of a resonance between it and the extended NLTL modes. A wake field excitation is detected directly from ILM velocity experiments by the decrease in ILM speed and by the observation of the wake. Its properties are quantified via a two-dimensional Fourier map in the frequency-wavenumber domain, determined from the measured spatial-time voltage pattern. Simulations support and extend these experimental findings. We find for the capacitive+inductive NLTL configuration, when the two nonlinear terms are theoretically balanced, the wake excitation is calculated to become very small, giving rise to supertransmission over an extended driving frequency range.

4.
Horm Metab Res ; 45(12): 856-61, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23979791

RESUMO

The aim of this study was to investigate the differences between rats and hamsters, Two of the most widely used experimental animals, with respect to the effects of microsomal membrane solubilization on the inhibition of liver 11ß-hydroxysteroid dehydrogenase (11ß-HSDI) enzyme by bile acids. Liver microsome fractions were prepared, and the 11ß-HSDI enzymatic activity was measured using cortisone as a substrate. The substrate and various concentrations of bile acids were added to the assay mixtures. After incubation, the products were extracted and analyzed using high-performance liquid chromatography. To investigate the effect of detergent on the inhibitory effects of bile acids, we conducted inhibition tests using Triton X-100-solubilized animal liver microsomes. When solubilized microsomes were used, all bile acids inhibited 11ß-HSDI from rats and hamsters to various degrees. 7α-Hydroxycholanoic acids (cholic acid and chenodeoxycholic acid) in particular had strong inhibitory activities. In hamsters, 7ß-hydroxycholanoic acid (ursodeoxycholic acid) was the strongest inhibitor among the bile acids tested, although its effect was not very strong. When nonsolubilized microsomes were used, deoxycholic acid did not inhibit but rather enhanced the enzymatic activity in both animals. Microsomal content of cholesterol and phospholipids are significantly different between rats and hamsters. Species differences in bile acid inhibition of nonsolubilized microsomes might be reflected not only by structural difference of bile acids, which affect membrane solubilization and enzyme activity directly, but also species difference in microsomal membrane lipid content.


Assuntos
11-beta-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , Ácidos e Sais Biliares/farmacologia , Membrana Celular/metabolismo , Microssomos Hepáticos/enzimologia , 11-beta-Hidroxiesteroide Desidrogenases/metabolismo , Animais , Membrana Celular/efeitos dos fármacos , Ácido Quenodesoxicólico/farmacologia , Cricetinae , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Ratos , Ratos Wistar , Solubilidade , Especificidade da Espécie
5.
Phys Rev E ; 107(3-1): 034202, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37072939

RESUMO

A well-known feature of a propagating localized excitation in a discrete lattice is the generation of a backwave in the extended normal mode spectrum. To quantify the parameter-dependent amplitude of such a backwave, the properties of a running intrinsic localized mode (ILM) in electric, cyclic, dissipative, nonlinear 1D transmission lines, containing balanced nonlinear capacitive and inductive terms, are studied via simulations. Both balanced and unbalanced damping and driving conditions are treated. The introduction of a unit cell duplex driver, with a voltage source driving the nonlinear capacitor and a synchronized current source, the nonlinear inductor, provides an opportunity to design a cyclic, dissipative self-dual nonlinear transmission line. When the self-dual conditions are satisfied, the dynamical voltage and current equations of motion within a cell become the same, the strength of the fundamental, resonant coupling between the ILM and the lattice modes collapses, and the associated fundamental backwave is no longer observed.

6.
Nature ; 440(7081): 184-6, 2006 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-16525466

RESUMO

The prompt gamma-ray emission from gamma-ray bursts (GRBs) should be detectable out to distances of z > 10 (ref. 1), and should therefore provide an excellent probe of the evolution of cosmic star formation, reionization of the intergalactic medium, and the metal enrichment history of the Universe. Hitherto, the highest measured redshift for a GRB has been z = 4.50 (ref. 5). Here we report the optical spectrum of the afterglow of GRB 050904 obtained 3.4 days after the burst; the spectrum shows a clear continuum at the long-wavelength end of the spectrum with a sharp cut-off at around 9,000 A due to Lyman alpha absorption at z approximately 6.3 (with a damping wing). A system of absorption lines of heavy elements at z = 6.295 +/- 0.002 was also detected, yielding the precise measurement of the redshift. The Si ii fine-structure lines suggest a dense, metal-enriched environment around the progenitor of the GRB.

7.
Thorax ; 63(9): 810-6, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18276722

RESUMO

BACKGROUND: A Th1 predominant immune response has been shown in acute hypersensitivity pneumonitis. Predominance of Th2 appears to favour the development of pulmonary fibrosis through the profibrotic process and has been described as crucial in the progression of idiopathic pulmonary fibrosis. Chronic bird fancier's lung (cBFL) can present with a histological pattern of usual interstitial pneumonia (UIP)-like lesions. Little is known about the Th1/Th2 balance in the pathogenesis of cBFL. METHODS: To evaluate the relevance of Th1-type chemokines (interferon-inducible protein, IP-10) and Th2-type chemokines (thymus- and activation-regulated chemokine, TARC) and their receptors (CXCR3 and CCR4) to the histological patterns of cBFL, 40 patients with cBFL who underwent surgical lung biopsies, 12 with acute BFL (aBFL) and 10 healthy volunteers were analysed. IP-10 and TARC levels in serum and bronchoalveolar lavage (BAL) fluid were measured by ELISA. Immunohistochemistry for CXCR3 and CCR4 was performed on surgical lung specimens. RESULTS: The ratio of TARC to IP-10 in the serum of patients with UIP-like lesions was significantly higher than in patients with cNSIP/OP-like lesions, aBFL and healthy volunteers. The ratio of CCR4 to CXCR3 in patients with UIP-like lesions was significantly higher than in those with cNSIP/OP-like lesions and fNSIP-like lesions. The ratio of CCR4-positive to CXCR3-positive cells correlated with the ratio of TARC to IP-10 in serum. CONCLUSIONS: A Th2 predominant immune response may play an important role in the development of UIP-like lesions, as already observed in idiopathic pulmonary fibrosis. A Th1 predominance may play a role in the development of cNSIP/OP-like lesions in cBFL.


Assuntos
Pulmão do Criador de Aves/metabolismo , Quimiocina CCL17/metabolismo , Quimiocina CXCL10/metabolismo , Fibrose Pulmonar/metabolismo , Pulmão do Criador de Aves/etiologia , Pulmão do Criador de Aves/imunologia , Líquido da Lavagem Broncoalveolar/imunologia , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Fibrose Pulmonar/etiologia , Fibrose Pulmonar/imunologia , Receptores CCR4/metabolismo , Receptores CXCR3/metabolismo
8.
Cancer Res ; 48(10): 2819-24, 1988 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-3359442

RESUMO

The present study demonstrates that normal human fibroblasts (WI-38) exert a profound influence on the growth and differentiation of HSGc-C5, a clonal neoplastic epithelial cell line of human salivary gland origin. Coculture of HSGc-C5 with WI-38 resulted in a slowing of growth and an increase in glycosaminoglycan synthesis by an indirect effect involving a diffusible factor(s). Conditioned medium (CM) from WI-38 grown in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum affected HSGc-C5 as follows. The CM suppressed growth of monolayer cells; inhibited DNA synthesis; suppressed growth (decrease in size of colonies) in semisolid agar; stimulated glycosaminoglycan synthesis, induced expression of functional markers of the salivary gland, such as the secretory component, lactoferrin, and lysozyme; inhibited expression of alkaline phosphatase; and induced morphological alteration into elongated cells. These findings strongly suggest that WI-38 CM contains a factor(s) which inhibits growth and induces differentiation of HSGc-C5. The CM was also active on other human cancer cells as a growth inhibitor, but not on normal human fibroblasts. Partial purification and characterization of the factor(s) suggests that it may be a novel protein carrying both tumor inhibiting and differentiation inducing activities.


Assuntos
Adenocarcinoma/patologia , Fibroblastos/fisiologia , Neoplasias das Glândulas Salivares/patologia , Diferenciação Celular , Divisão Celular , Meios de Cultura , DNA/biossíntese , Fibroblastos/análise , Glicosaminoglicanos/biossíntese , Inibidores do Crescimento/análise , Humanos , Células Tumorais Cultivadas
9.
Cancer Res ; 50(13): 4139-45, 1990 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-2162254

RESUMO

Two cell lines (ACCS and ACCY) were isolated from two individuals with adenoid cystic carcinoma (AdCC) using tissue culture techniques. Both cell lines have similar morphology, i.e., elongated and flattened cells with slender cytoplasmic processes. The two cell lines tend to form pseudocysts, which are a specific architectural feature of AdCC. Coexpression of cytokeratin and vimentin was found in the two cell lines, which occasionally also contained S-100 protein and lactoferrin or lysozyme immunoreactivity. Moreover, ACCS and ACCY displayed potential for the production of a large amount of extracellular matrix including basal lamina components such as fibronectin, laminin, and type IV collagen and glycosaminoglycans which are also part of the basal lamina. These findings suggest that the tumor cells, probably basal or myoepithelial like cells, are responsible for the formation of the peculiar stroma of AdCC consisting of a large amount of collagen-like fibers, basal lamina components, and mucopolysaccharides.


Assuntos
Carcinoma Adenoide Cístico/patologia , Neoplasias das Glândulas Salivares/patologia , Carcinoma Adenoide Cístico/análise , Carcinoma Adenoide Cístico/metabolismo , Carcinoma Adenoide Cístico/ultraestrutura , Colágeno/biossíntese , Feminino , Glicosaminoglicanos/biossíntese , Humanos , Microscopia Eletrônica , Pessoa de Meia-Idade , Neoplasias das Glândulas Salivares/análise , Neoplasias das Glândulas Salivares/metabolismo , Neoplasias das Glândulas Salivares/ultraestrutura , Glândulas Salivares Menores , Células Tumorais Cultivadas/metabolismo , Células Tumorais Cultivadas/patologia , Células Tumorais Cultivadas/ultraestrutura
10.
J Biochem ; 127(2): 345-50, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10731703

RESUMO

A heterologous expression system of the blue copper-containing nitrite reductase from Alcaligenes xylosoxidans GIFU1051 (AxgNIR) was constructed, and the purified recombinant enzyme was characterized. All the characteristic spectroscopic properties and enzyme activity of native AxgNIR were retained in the copper-reconstituted recombinant protein expressed in Escherichia coli, indicating the correct coordination of two types of Cu (type 1 and 2) in the recombinant enzyme. Moreover, two conserved noncoordinate residues, Asp98 and His255, located near the type 2 Cu site were replaced to elucidate the catalytic residue(s) of NIR. The Asp98 residue hydrogen-bonded to the water molecule ligating the type 2 Cu was changed to Ala, Asn, or Glu, and the His255 residue hydrogen-bonded to Asp98 through the water molecule was replaced with Ala, Lys, or Arg. The catalytic rate constants of all mutants were decreased to 0.4-2% of those of the recombinant enzyme, and the apparent K(m) values for nitrite were greatly increased in the Asp98 mutants. All the steady-state kinetic data of the mutants clearly demonstrate that both Asp98 and His255 are involved not only in the catalytic reaction but also in the substrate anchoring.


Assuntos
Cobre/metabolismo , Nitrito Redutases/química , Nitrito Redutases/metabolismo , Alcaligenes/enzimologia , Sequência de Aminoácidos , Ácido Aspártico , Sítios de Ligação , Sequência Conservada , Histidina , Cinética , Dados de Sequência Molecular , Mutação , Nitrito Redutases/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Relação Estrutura-Atividade
11.
Brain Res Bull ; 35(1): 93-5, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7953763

RESUMO

To understand the modulation of periodontal mechanoreceptor activity on mastication, the jaw-opening reflex (JOR) evoked by electrical stimulation of the inferior alveolar nerve (IAN) was studied during chewing in freely behaving rabbits. Spontaneous chewing movements were intact from the IAN stimulation below two times the threshold (T) which was measured at rest. As the stimulus intensity was increased to more than 2.5 T, the amplitude of the masseter activity decreased or it was abolished; however, the chewing rhythm was still maintained up to 3.0 T. When the low-threshold primary afferents were tested while the rabbit chewed pellets rhythmically, the amplitude in the JOR was inhibited below the prior control level. The inhibitory effect on the JOR was larger in the opening phase than that in the closing phase. In conclusion, the JOR was tonically depressed during the masticatory cycle and the inhibition of the JOR was rhythmically modulated in a phase-linked manner that was larger in the opening phase than in the closing phase.


Assuntos
Arcada Osseodentária/fisiologia , Mastigação/fisiologia , Mecanorreceptores/fisiologia , Reflexo/fisiologia , Animais , Estimulação Elétrica , Masculino , Coelhos
12.
Breast Cancer ; 8(2): 116-24, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11342984

RESUMO

BACKGROUND: The purpose of this study was to evaluate the diagnostic value and clinical significance of three-dimensional MR imaging of the breast in patients with mammographically detected suspicious microcalcifications. METHODS: Forty patients with suspicious microcalcifications on mammography were evaluated with three-dimensional MR imaging. MR findings were grouped mainly by distribution of abnormal enhancement (linear, focal-clumped, segmental-clumped, segmental-stippled and diffuse-stippled). These findings were compared with the mammography findings according to the criteria of the Breast Imaging Reporting and Data System (BI-RADS) and histopathologic data. RESULTS: Twenty patients had proven malignancies, most frequently ductal carcinoma in situ. For all the cases, linear (100%) and segmental-clumped type (100%) enhancement on MR imaging showed a significantly higher risk for malignancy. Diffuse stippled type (7%) and no enhancement (0%) on MR imaging indicated the lowest possibility of malignancy. 3D-MR imaging showed a sensitivity of 90%, a specificity of 95% and an overall accuracy of 93% in this study. CONCLUSIONS: Three-dimensional MR imaging of the breast can more accurately diagnose ductal carcinoma in situ. Combined with mammography, this procedure is useful for reducing the number of false-positive biopsies and helpful for deciding the better management of patients with mammographically detected suspicious microcalcifications.


Assuntos
Doenças Mamárias/diagnóstico , Mama/patologia , Calcinose/diagnóstico , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Neoplasias da Mama/diagnóstico , Carcinoma Intraductal não Infiltrante/diagnóstico , Diagnóstico Diferencial , Feminino , Gadolínio DTPA , Humanos , Mamografia , Pessoa de Meia-Idade
13.
Gan To Kagaku Ryoho ; 21 Suppl 4: 471-6, 1994 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-7802452

RESUMO

We attempted to instruct the outpatients with malignant liver tumor (metastatic liver cancer and advanced hepatocellular carcinoma) who received intermittent arterial infusion chemotherapy using implanted reservoir to detach the devices for arterial infusion by themselves at home. All patients who received our instruction could master self-detachment at home, which shortened the hospitalized day. And patients' desire for this treatment promoted with improvement of the recognition of their families to participate in treatment together. We experienced no trouble which disturb the treatment. This methods was considered to promote the improvement of QOL of these patients.


Assuntos
Assistência Ambulatorial , Carcinoma Hepatocelular/tratamento farmacológico , Terapia por Infusões no Domicílio , Bombas de Infusão Implantáveis , Neoplasias Hepáticas/tratamento farmacológico , Carcinoma Hepatocelular/secundário , Feminino , Serviços Hospitalares de Assistência Domiciliar , Humanos , Infusões Intra-Arteriais , Neoplasias Hepáticas/patologia , Masculino , Autoadministração
16.
Nucleic Acids Symp Ser ; (44): 187-8, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-12903331

RESUMO

To study RNA-peptide interactions, we performed an in vitro selection of RNA on a 27 MHz quartz-crystal microbalance (QCM) on which a simple R5 helix peptide was immobilized as a model of N peptide from bacteriophade lambda. The consensus sequences including a GNRA tetraloop were obtained from a random RNA pool after the 7th cycle selection.


Assuntos
Proteínas de Ligação a RNA/metabolismo , RNA/metabolismo , Motivos de Aminoácidos , Bacteriófago lambda/genética , Sequência de Bases , Sítios de Ligação , Técnicas In Vitro , Cinética , Conformação de Ácido Nucleico , RNA/química , RNA/genética , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Proteínas Virais Reguladoras e Acessórias/química , Proteínas Virais Reguladoras e Acessórias/genética , Proteínas Virais Reguladoras e Acessórias/metabolismo
17.
Nucleic Acids Symp Ser ; (44): 245-6, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-12903360
18.
Nucleic Acids Symp Ser ; (42): 193-4, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10780445

RESUMO

A highly sensitive 27 MHz quartz-crystal microbalance (QCM) was applied as a device of dsDNA in vitro selection. When GCN4-bZIP peptides were immobilized on the small Au electrode of the QCM, dsDNAs having TGACTCA sequences could be mainly selected from DNA library having a 15-bp random region, which was consistent with the sequence observed by X-ray crystallography.


Assuntos
DNA/química , Proteínas Fúngicas/química , Conformação de Ácido Nucleico , Proteínas Quinases/química , Proteínas de Saccharomyces cerevisiae , Sequência de Aminoácidos , Sequência de Bases , Cristalografia por Raios X , DNA/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Proteínas Fúngicas/metabolismo , Cinética , Zíper de Leucina , Modelos Moleculares , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Proteínas Quinases/metabolismo
19.
Nucleic Acids Res Suppl ; (1): 261-2, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-12836364

RESUMO

We report here kinetic analyses of the hydrolysis of DNA by the ATP-dependent DNase using a DNA-immobilized quartz-crystal microbalance (QCM), which enables in situ real-time monitoring both the binding of enzyme and the hydrolysis reaction on DNA strands, as mass changes.


Assuntos
Trifosfato de Adenosina/metabolismo , DNA/metabolismo , Desoxirribonucleases/metabolismo , Quartzo/química , Sequência de Bases , Cristalização , DNA/química , Hidrólise , Cinética , Dados de Sequência Molecular , Ligação Proteica
20.
Nucleic Acids Symp Ser ; (44): 243-4, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-12903359

RESUMO

We report here binding kinetics of proliferating cell nuclear antigen (PCNA) to the dsDNA immobilized on a 27 MHz quartz-crystal microbalance. PCNA is a toroidal-shaped protein and encircles dsDNA sliding along the strand. The binding behavior of this sliding clamp protein was compared with those of other side binding proteins such as GCN4-bZIP and Zn-finger peptides.


Assuntos
DNA/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Sequência de Bases , Fatores de Transcrição de Zíper de Leucina Básica , DNA/química , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Fatores de Ligação G-Box , Técnicas In Vitro , Cinética , Conformação de Ácido Nucleico , Antígeno Nuclear de Célula em Proliferação/química , Ligação Proteica , Quartzo , Soluções , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Água , Dedos de Zinco
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