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1.
Nature ; 623(7987): 499-501, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37938777

RESUMEN

The majority of massive disk galaxies in the local Universe show a stellar barred structure in their central regions, including our Milky Way1,2. Bars are supposed to develop in dynamically cold stellar disks at low redshift, as the strong gas turbulence typical of disk galaxies at high redshift suppresses or delays bar formation3,4. Moreover, simulations predict bars to be almost absent beyond z = 1.5 in the progenitors of Milky Way-like galaxies5,6. Here we report observations of ceers-2112, a barred spiral galaxy at redshift zphot ≈ 3, which was already mature when the Universe was only 2 Gyr old. The stellar mass (M★ = 3.9 × 109 M⊙) and barred morphology mean that ceers-2112 can be considered a progenitor of the Milky Way7-9, in terms of both structure and mass-assembly history in the first 2 Gyr of the Universe, and was the closest in mass in the first 4 Gyr. We infer that baryons in galaxies could have already dominated over dark matter at z ≈ 3, that high-redshift bars could form in approximately 400 Myr and that dynamically cold stellar disks could have been in place by redshift z = 4-5 (more than 12 Gyrs ago)10,11.

3.
J Org Chem ; 84(8): 4932-4939, 2019 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-30721066

RESUMEN

The key macrocyclization step in the synthesis of simeprevir, a hepatitis C virus (HCV) antiviral drug, was studied. N-Boc substitution on the diene precursor changes the site of insertion of the metathesis catalyst and, consequently, the kinetic model of the ring closing metathesis (RCM), enabling a further increase in the macrocyclization efficiency under simulated high dilution (SHD) conditions. NMR of the inserted species of both first and second generation RCM catalysts are reported and discussed.


Asunto(s)
Antivirales/farmacología , Péptido Hidrolasas/metabolismo , Inhibidores de Proteasas/farmacología , Simeprevir/farmacología , Antivirales/síntesis química , Antivirales/química , Ciclización , Hepacivirus/efectos de los fármacos , Hepacivirus/enzimología , Hepatitis C/tratamiento farmacológico , Humanos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/química , Simeprevir/síntesis química , Simeprevir/química
4.
J Med Chem ; 62(6): 2974-2987, 2019 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-30810314

RESUMEN

In Alzheimer's disease, the density and spread of aggregated tau protein track well with neurodegeneration and cognitive decline, making the imaging of aggregated tau a compelling biomarker. A structure-activity relationship exploration around an isoquinoline hit, followed by an exploration of tolerated fluorination positions, allowed us to identify 9 (JNJ-64326067), a potent and selective binder to aggregated tau with a favorable pharmacokinetic profile and no apparent off-target binding. This was confirmed in rat and monkey positron emission tomography studies using [18F]9.


Asunto(s)
Descubrimiento de Drogas , Radioisótopos de Flúor/metabolismo , Isoquinolinas/farmacocinética , Tomografía de Emisión de Positrones , Piridinas/farmacocinética , Proteínas tau/metabolismo , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/metabolismo , Animales , Células Cultivadas , Femenino , Radioisótopos de Flúor/química , Radioisótopos de Flúor/farmacocinética , Hepatocitos/metabolismo , Humanos , Isoquinolinas/química , Macaca mulatta , Masculino , Piridinas/química , Ratas , Ratas Wistar , Relación Estructura-Actividad
5.
Nature ; 513(7518): 394-7, 2014 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-25162527

RESUMEN

Most massive galaxies are thought to have formed their dense stellar cores in early cosmic epochs. Previous studies have found galaxies with high gas velocity dispersions or small apparent sizes, but so far no objects have been identified with both the stellar structure and the gas dynamics of a forming core. Here we report a candidate core in the process of formation 11 billion years ago, at redshift z = 2.3. This galaxy, GOODS-N-774, has a stellar mass of 100 billion solar masses, a half-light radius of 1.0 kiloparsecs and a star formation rate of solar masses per year. The star-forming gas has a velocity dispersion of 317 ± 30 kilometres per second. This is similar to the stellar velocity dispersions of the putative descendants of GOODS-N-774, which are compact quiescent galaxies at z ≈ 2 (refs 8-11) and giant elliptical galaxies in the nearby Universe. Galaxies such as GOODS-N-774 seem to be rare; however, from the star formation rate and size of this galaxy we infer that many star-forming cores may be heavily obscured, and could be missed in optical and near-infrared surveys.

6.
Chem Commun (Camb) ; (15): 1928-9, 2003 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-12932037

RESUMEN

Acid zeolites like H-Beta are efficient heterogeneous catalysts for racemization of benzylic alcohols in water; by combination of the racemization with an enzymatic kinetic resolution in a two-phase system, enantiomerically pure esters were obtained in high yield via a dynamic kinetic resolution.


Asunto(s)
Alcoholes Bencílicos/química , Enzimas/química , Zeolitas/química , Catálisis , Química Orgánica/métodos , Cinética , Solventes/química , Estereoisomerismo
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