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1.
Nature ; 597(7877): 489-492, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34552254

RESUMO

Over the past decades, rest-frame ultraviolet (UV) observations have provided large samples of UV luminous galaxies at redshift (z) greater than 6 (refs. 1-3), during the so-called epoch of reionization. While a few of these UV-identified galaxies revealed substantial dust reservoirs4-7, very heavily dust-obscured sources at these early times have remained elusive. They are limited to a rare population of extreme starburst galaxies8-12 and companions of rare quasars13,14. These studies conclude that the contribution of dust-obscured galaxies to the cosmic star formation rate density at z > 6 is sub-dominant. Recent ALMA and Spitzer observations have identified a more abundant, less extreme population of obscured galaxies at z = 3-6 (refs. 15,16). However, this population has not been confirmed in the reionization epoch so far. Here, we report the discovery of two dust-obscured star-forming galaxies at z = 6.6813 ± 0.0005 and z = 7.3521 ± 0.0005. These objects are not detected in existing rest-frame UV data and were discovered only through their far-infrared [C II] lines and dust continuum emission as companions to typical UV-luminous galaxies at the same redshift. The two galaxies exhibit lower infrared luminosities and star-formation rates than extreme starbursts, in line with typical star-forming galaxies at z ≈ 7. This population of heavily dust-obscured galaxies appears to contribute 10-25% to the z > 6 cosmic star formation rate density.

2.
Phys Rev Lett ; 85(9): 1982-5, 2000 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-10970663

RESUMO

Muon spin relaxation has been measured in Sr(Cu1-xZnx)2O3. The results for low Zn concentration x0 occurred with increasing x around x approximately 0.8%, accompanied by a change of line shape to that expected in a concentrated magnetic environment. Analyses of the results for x>/=0.8% suggest that the majority of Cu moments participate in spin freezing, yet with a significantly reduced and spatially inhomogeneous moment size having a 1D correlation length xi approximately 6 lattice units, or a 2D correlation area involving approximately 19 Cu spins.

3.
Biomed Environ Sci ; 9(2-3): 209-12, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8886333

RESUMO

We examined the effects of dietary proso-millet protein on plasma levels of high-density lipoprotein (HDL) cholesterol in different rats from animals reported in our previous studies. The results showed also, in this animal, that the ingestion of the millet protein elevates plasma levels of HDL-cholesterol like our earlier works. Taking into account the anti-atherogenic function of HDL, therefore, the millet protein would be useful as a new food ingredient which has the function that regulates cholesterol metabolism.


Assuntos
Proteínas Alimentares/farmacologia , Lipoproteínas LDL/sangue , Panicum/química , Proteínas de Plantas/farmacologia , Animais , Colesterol/sangue , Colesterol/metabolismo , Ingestão de Alimentos/fisiologia , Fígado/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Especificidade da Espécie , Triglicerídeos/sangue , Triglicerídeos/metabolismo , Aumento de Peso/fisiologia
4.
Biosci Biotechnol Biochem ; 59(2): 333-5, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7766034

RESUMO

We examined the effects of dietary proso-millet protein on plasma concentration of high-density lipoprotein (HDL) cholesterol in mice. The results confirmed also, in this animal, the elevation of plasma concentration of HDL cholesterol without the involvement in raising the concentration of low-density lipoprotein cholesterol like those with rats reported in our previous paper. This would suggest a beneficial effect of millet protein on cholesterol metabolism.


Assuntos
HDL-Colesterol/sangue , Proteínas Alimentares/administração & dosagem , Proteínas de Plantas/administração & dosagem , Aminoácidos/análise , Animais , Caseínas/administração & dosagem , HDL-Colesterol/metabolismo , Fibras na Dieta/administração & dosagem , Proteínas Alimentares/análise , Proteínas Alimentares/farmacologia , Ingestão de Alimentos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Panicum/química , Proteínas de Plantas/química , Proteínas de Plantas/farmacologia , Proteínas de Vegetais Comestíveis/administração & dosagem , Proteínas de Soja , Glycine max , Triglicerídeos/sangue , Triglicerídeos/metabolismo , Aumento de Peso
5.
Phys Rev Lett ; 89(24): 247001, 2002 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-12484973

RESUMO

The c-axis reflectivity spectrum of underdoped YBa2Cu3O6.6 (YBCO) is measured below T(c)=59 K in parallel magnetic fields H parallel CuO2 up to 7 T. Upon application of a parallel field, a new peak appears at finite frequency in the optical conductivity at the expense of suppression of c-axis condensate weight. We conclude that the dramatic change originates from different Josephson coupling strengths between bilayers with and without Josephson vortices. We find that the 400 cm(-1) broad conductivity peak in YBCO gains the spectral weight under parallel magnetic field; this indicates that the condensate weight at omega=0 is distributed to this peak as well as to the new optical Josephson mode.

6.
Phys Rev Lett ; 91(20): 207603, 2003 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-14683396

RESUMO

Muon spin relaxation and magnetic susceptibility measurements have been performed on the pure and diluted spin 1/2 kagomé system (CuxZn(1-x))3V2O7(OH)2 2H2O. In the pure x=1 system we found a slowing down of Cu spin fluctuations with decreasing temperature towards T approximately 1 K, followed by slow and nearly temperature-independent spin fluctuations persisting down to T=50 mK, indicative of quantum fluctuations. No indication of static spin freezing was detected in either of the pure (x=1.0) or diluted samples. The observed magnitude of fluctuating fields indicates that the slow spin fluctuations represent an intrinsic property of kagomé network rather than impurity spins.

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