Predicting Co-59 NMR Chemical Shit using the NMR-DKH Basis Sets

The cobalt-59 nucleus is an NMR active nucleus with the nuclear spin I = 7/2 and has a natural abundance of 100 %. It is an important nucleus because it has ease of detectable NMR signals both liquid and solid-state. The Co-59 NMR chemical shift range is one of the largest known in NMR spectroscopy, spanning some 18,000 ppm or more. However, Co-59 NMR is an extremely sensitive technique to external factors such as pressure, temperature, and others. Therefore, predicting Co-59 NMR chemical shift might be useful to assist experimentalists in the structural characterization. In the present study, we propose a new NMR-DKH basis set for Co atom to predict NMR chemical shift in Co complexes. Besides, we proposed a computational protocol (Functional DFT/Co basis set/Ligands basis set) for the prediction of the structure and, later, for the prediction of the Co-59 NMR chemical shift using 6 Co complexes as model systems. The results show that the computational protocol (NMR/structure) GIAO-B3LYP/NMR-DKH/IEF-PCM(UFF)//CAM-B3LYP/LANL2DZ/jorge-DZP/IEF-PCM(UFF) presents a mean relative deviation (DRM) of 1.48% for the structure, a mean absolute deviation (MAD) of 101 ppm and a DRM of 1.2% for the Co-59 chemical shift. Finally, the protocol was corrected by a linear regression model giving a MAD and MRD of 57 ppm and 0.7%, respectively.

LeMMINGs – II. The e-MERLIN legacy survey of nearby galaxies. The deepest radio view of the Palomar sample on parsec scale

ABSTRACT We present the second data release of high-resolution (≤0.2 arcsec) 1.5-GHz radio images of 177 nearby galaxies from the Palomar sample, observed with the e-MERLIN array, as part of the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies Sample (LeMMINGs) survey. Together with the 103 targets of the first LeMMINGs data release, this represents a complete sample of 280 local active (LINER and Seyfert) and inactive galaxies (H ii galaxies and absorption line galaxies, ALG). This large program is the deepest radio survey of the local Universe, ≳1017.6 W Hz−1, regardless of the host and nuclear type: we detect radio emission ≳0.25 mJy beam−1 for 125/280 galaxies (44.6 per cent) with sizes of typically ≲100 pc. Of those 125, 106 targets show a core which coincides within 1.2 arcsec with the optical nucleus. Although we observed mostly cores, around one third of the detected galaxies features jetted morphologies. The detected radio core luminosities of the sample range between ∼1034 and 1040 erg s−1. LINERs and Seyferts are the most luminous sources, whereas H ii galaxies are the least. LINERs show FR I-like core-brightened radio structures while Seyferts reveal the highest fraction of symmetric morphologies. The majority of H ii galaxies have single radio core or complex extended structures, which probably conceal a nuclear starburst and/or a weak active nucleus (seven of them show clear jets). ALGs, which are typically found in evolved ellipticals, although the least numerous, exhibit on average the most luminous radio structures, similar to LINERs.

Cosmic rays from the nearby starburst galaxy NGC 253: the effect of a low-luminosity active galactic nucleus

ABSTRACT NGC 253 is a nearby starburst galaxy in the Sculptor group located at a distance of ∼3.5 Mpc that has been suggested by some authors as a potential site for cosmic ray acceleration up to ultrahigh energies. Its nuclear region is heavily obscured by gas and dust, which prevents establishing whether or not the galaxy harbours a supermassive black hole coexisting with the starburst. Some sources have been proposed in the literature as candidates for an active nucleus. In this work, we aim at determining the implications that the presence of a supermassive black hole at the nucleus of NGC 253 might have on cosmic ray acceleration. With this aim, we model the accretion flow on to the putative active nucleus, and we evaluate the feasibility of particle acceleration by the black hole dynamo mechanism. As a by-product, we explore the potential contribution from non-thermal particles in the accretion flow to the high-energy emission of the galaxy. We found that in the three most plausible nucleus candidates, the emission of the accretion flow would inhibit the black hole dynamo mechanism. To rule out completely the influence that a putative nucleus in NGC 253 might have in cosmic ray acceleration, a better clarification concerning the true nature of the nucleus is needed.

The Therapeutic and Diagnostic Value of Fluorine

Fluorine has a useful positron transmitting isotope and it enjoys broad application in the medical field. It is utilized in fluorinated agents,therapeutic sciences and steroid field. Fluorine incorporation viafluoroalkylation is a useful approach in the development of new functional materials and in drug design. Fluorine also plays its role as an anticancer agent and is a successful chemotherapeutic agent for certain sorts of malignant growth. 5-fluorouracil plays a vital role in the treatment of cancer. 18 Facts as a radio label tracer atom in PET imaging. 19 F has the second most sensitive and stable NMR-active nucleus.

Two-photon active nucleus-targeting carbon dots: enhanced ROS generation and photodynamic therapy for oral cancer

Novel conjugated carbon dots (CDs) were synthesized as two-photon active photosensitisers to unleash lethal reactive oxygen species (ROS) for nucleus-targeting photodynamic therapy (PDT).

Complex molecular gas kinematics in the inner 5 kpc of 4C12.50 as seen by ALMA

The nearby system 4C12.50, also known as IRAS 13451+1217 and PKS 1345+12, is a merger of gas-rich galaxies with infrared and radio activity. It has a perturbed interstellar medium (ISM) and a dense configuration of gas and dust around the nucleus. The radio emission at small (∼100 pc) and large (∼100 kpc) scales, as well as the large X-ray cavity in which the system is embedded, are indicative of a jet that could have affected the ISM. We carried out observations of the CO(1−0), (3−2), and (4−3) lines with the Atacama Large Millimeter Array (ALMA) to determine basic properties (i.e., extent, mass, and excitation) of the cold molecular gas in this system, including its already-known wind. The CO emission reveals the presence of gaseous streams related to the merger, which result in a small (∼4 kpc-wide) disk around the western nucleus. The disk reaches a rotational velocity of 200 km s−1, and has a mass of 3.8(±0.4) × 109 M⊙. It is truncated at a gaseous ridge north of the nucleus that is bright in [O III]. Regions with high-velocity CO emission are seen at signal-to-noise ratios of between 3 and 5 along filaments that radially extend from the nucleus to the ridge and that are bright in [O III] and stellar emission. A tentative wind detection is also reported in the nucleus and in the disk. The molecular gas speed could be as high as 2200 km s−1 and the total wind mass could be as high as 1.5(±0.1) × 109 M⊙. Energetically, it is possible that the jet, assisted by the radiation pressure of the active nucleus or the stars, accelerated clouds inside an expanding bubble.

Reflection geometries in absorbed and unabsorbed AGN

Context. The hard X-ray emission of active galactic nuclei (AGN), and in particular, the reflection component, is shaped by the innermost and outer regions of the galactic nucleus. Aims. Our main goal is to investigate the variation of the Compton hump amongst a population of sources and correlate it with other spectral properties to constrain the source geometry. Methods. We studied the NuSTAR hard X-ray spectra of a sample of 83 AGN and performed a detailed spectral analysis of each of them. Based on their spectral shape, we divided the sample into five categories and also studied their stacked spectra. Results. We found a stronger reflection in mildly obscured sources, which verifies the results reported in previous works. In addition, the reflection behaviour, and probably origin, varies with absorption. The accretion disc seems to be the main reflector in unabsorbed sources. A clumpy torus seems to produce most of the reflection in obscured sources. The filling factor of the clouds surrounding the active nucleus is a key parameter that drives the appearance of AGN. Finally, we found that the Fe line and the Compton hump are roughly correlated, as expected.

Multiwavelength campaign on Mrk 509

Aims. To elucidate the location, physical conditions, mass outflow rate, and kinetic luminosity of the outflow from the active nucleus of the Seyfert 1 galaxy Mrk 509, we used coordinated UV and X-ray spectral observations in 2012 to follow up our lengthier campaign conducted in 2009. Methods. We observed Mrk 509 with the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST) on 2012-09-03 and 2012-10-11 coordinated with X-ray observations using the High Energy Transmission Grating on the Chandra X-ray Observatory. Our far-ultraviolet spectra used grating G140L on COS to cover wavelengths from 920–2000 Å at a resolving power of ∼2000, and gratings G130M and G160M to cover 1160–1750 Å at a resolving power of ∼15, 000. Results. We detect variability in the blueshifted UV absorption lines on timescales spanning 3–12 years. The inferred densities in the absorbing gas are greater than log n cm−3 ∼ 3. For ionization parameters ranging over log U = −1.5 to −0.2, we constrain the distances of the absorbers to be closer than 220 pc to the active nucleus. Conclusions. The impact on the host galaxy appears to be confined to the nuclear region.