Explore the vast range of titles available.

The influence of organic C quantity and quality on denitrification in riparian environments is poorly understood. We measured denitrification potential (DNP), organic matter, and several fractions of organic C in surface soils and subsurface sediments in a river riparian zone. Surface soils in conifer forest peat, mixed forest, and marsh sites had similar DNP, although mean organic matter ranged from 9.4% (marsh) to 19.6% (mixed forest) and 36.6% (peat). These soils also differed widely in organic C, water-extractable C, and anaerobic mineralizable C. Mean DNP in peat at depths of 0.8 to 1.4 m was four times lower than in the surface peat. Mean organic matter and organic C were significantly greater in the deep peat than at the surface, whereas the other C fractions were similar. Mean organic matter content of buried channel sediments at depths of 2 to 3 m was 3.6%; however, mean DNP was 75 to 80 times lower than in the surface mixed forest and marsh soils. When the three surface soil sites were considered separately, anaerobic mineralizable C showed the highest correlation with DNP in the marsh soils (r = 0.87) and the conifer peat soil (r = 0.82). Water-extractable C was also highly correlated with DNP in the marsh soils (r = 0.81). Correlations between DNP and either organic matter or the three C fractions were not significant in the deep peat, whereas the former channel sediments showed a significant relationship between DNP and both organic matter (r = 0.81) and water-extractable C (r = 0.81). These results show that C quantity and quality influence DNP, but no single index was a good predictor for all soil types. [PUBLICATION ABSTRACT]

Gastrointestinal (GI) cancers cause one-third of all cancer-related deaths worldwide. Natural compounds are emerging as alternative or adjuvant cancer therapies given their distinct advantage of manipulating multiple pathways to both suppress tumor growth and alleviate cancer comorbidities; however, concerns regarding efficacy, bioavailability, and safety are barriers to their development for clinical use. Emodin (1,3,8-trihydroxy-6-methylanthraquinone), a Chinese herb-derived anthraquinone, has been shown to exert anti-tumor effects in colon, liver, and pancreatic cancers. While the mechanisms underlying emodin’s tumoricidal effects continue to be unearthed, recent evidence highlights a role for mitochondrial mediated apoptosis, modulated stress and inflammatory signaling pathways, and blunted angiogenesis. The goals of this review are to (1) highlight emodin’s anti-cancer properties within GI cancers, (2) discuss the known anti-cancer mechanisms of action of emodin, (3) address emodin’s potential as a treatment complementary to standard chemotherapeutics, (4) assess the efficacy and bioavailability of emodin derivatives as they relate to cancer, and (5) evaluate the safety of emodin.

For the first time, the sulphur abundance relative to hydrogen (S/H) in the Narrow Line Regions of a sample of Seyfert 2 nuclei (Sy 2s) has been derived via direct estimation of the electron temperature. Narrow emission line intensities from the SDSS DR17 [in the wavelength range 3000 < \\(\\lambda\\) < 9100] and from the literature for a sample of 45 nearby (\\(z\\) < 0.08) Sy 2s were considered. Our direct estimates indicate that Sy 2s have similar temperatures in the gas region where most of the S+ ions are located in comparison with that of star-forming regions (SFs). However, Sy 2s present higher temperature values (\\(\\sim\\)10000 K) in the region where most of the S++ ions are located relative to that of SFs. We derive the total sulphur abundance in the range of 6.2 < 12 + log(S/H) < 7.5, corresponding to 0.1-1.8 times the solar value. These sulphur abundance values are lower by \\(\\sim\\)0.4 dex than those derived in SFs with similar metallicity, indicating a distinct chemical enrichment of the ISM for these object classes. The S/O values for our Sy 2 sample present an abrupt (\\(\\sim\\)0.5 dex) decrease with increasing O/H for the high metallicity regime [12 + log(O/H) > 8.7)], what is not seen for the SFs. However, when our Sy 2 estimates are combined with those from a large sample of star-forming regions, we did not find any dependence between S/O and O/H.

Actinium-225 (225Ac) prostate-specific membrane antigen (PSMA) radioligand therapy (RLT) is a novel therapy for metastatic castration-resistant prostate cancer (mCRPC). We aimed to report the safety and antitumour activity of 225Ac-PSMA RLT of mCRPC in a large cohort of patients treated at multiple centres across the world. This retrospective study included patients treated at seven centres in Australia, India, Germany, and South Africa. We pooled data of consecutive patients of any age and Eastern Cooperative Oncology Group performance status with histopathologically confirmed adenocarcinoma of the prostate who were treated with one or more cycles of 8 MBq 225Ac-PSMA RLT administered intravenously for mCRPC. Previous lines of mCRPC treatment included taxane-based chemotherapy, androgen-receptor-axis inhibitors, lutetium-177 (177Lu) PSMA RLT, and radium-223 dichloride. The primary outcomes were overall survival and progression-free survival. Between Jan 1, 2016, and May 31, 2023, 488 men with mCRPC received 1174 cycles of 225Ac-PSMA RLT (median two cycles, IQR 2–4). The mean age of the patients was 68·1 years (SD 8·8), and the median baseline prostate-specific antigen was 169·5 ng/mL (IQR 34·6–519·8). Previous lines of treatment were docetaxel in 324 (66%) patients, cabazitaxel in 103 (21%) patients, abiraterone in 191 (39%) patients, enzalutamide in 188 (39%) patients, 177Lu-PSMA RLT in 154 (32%) patients, and radium-223 dichloride in 18 (4%) patients. The median follow-up duration was 9·0 months (IQR 5·0–17·5). The median overall survival was 15·5 months (95% CI 13·4–18·3) and median progression-free survival was 7·9 months (6·8–8·9). In 347 (71%) of 488 patients, information regarding treatment-induced xerostomia was available, and 236 (68%) of the 347 patients reported xerostomia after the first cycle of 225Ac-PSMA RLT. All patients who received more than seven cycles of 225Ac-PSMA RLT reported xerostomia. Grade 3 or higher anaemia occurred in 64 (13%) of 488 patients, leukopenia in 19 (4%), thrombocytopenia in 32 (7%), and renal toxicity in 22 (5%). No serious adverse events or treatment-related deaths were recorded. 225Ac-PSMA RLT shows a substantial antitumour effect in mCRPC and represents a viable therapy option in patients treated with previous lines of approved agents. Xerostomia is a common side-effect. Severe bone marrow and renal toxicity are less common adverse events. None.

The ionizing source of Low Ionization Nuclear Emission Regions (LINERs) is uncertain. Because of this, an empirical relation to determine the chemical abundances of these objects has not been proposed. In this work, for the first time, we derived two semi-empirical calibrations based on photoionization models to estimate the oxygen abundance of LINERS as a function of the \\(N2\\) and \\(O3N2\\) emission-line intensity ratios. These relations were calibrated using oxygen abundance estimations obtained by comparing the observational emission-line ratios of 43 LINER galaxies (taken from the MaNGA survey) and grids of photoionization models built with the {\\sc Cloudy} code assuming post-Asymptotic Giant Branch (post-AGB) stars with different temperatures. We found that the oxygen abundance of LINERs in our sample is in the \\(\\rm 8.48 <~ 12+log(O/H) <~ 8.84\\) range, with a mean value of \\(\\rm 12+\\log(O/H)=8.65\\). We recommend the use of the \\(N2\\) index to estimate the oxygen abundances of LINERs, since the calibration with this index presented a much smaller dispersion than the \\(O3N2\\) index. In addition, the estimated metallicities are in good agreement with those derived by extrapolating the disk oxygen abundance gradients to the centre of the galaxies showing that the assumptions of the models are suitable for LINERs. We also obtained a calibration between the logarithm of the ionization parameter and the [OIII]/[OII] emission-line ratio.

We build detailed composite models of photoionization and shock ionization based on the SUMA code to reproduce emission lines emitted from the Narrow Line Regions (NLR) of Seyfert 2 nuclei. The aim of this work is to investigate diagram AGN positions according to shock parameters, shock effects on the gas temperature and ionization structures and derive a semi-empirical abundance calibration based on emission-line ratios little sensitive to the shock presence. The models were used to reproduce optical (3000 < A < 7000) emission line intensities of 244 local (z < 0.4) Seyfert 2s, whose observational data were selected from Sloan Digital Sky Survey DR7. Our models suggest that shocks in Seyfert 2 nuclei have velocities in the range of 50-300 km/s and imply a narrower metallicity range (0.6 < (Z/Z) < 1.6) than those derived using pure photoionization models. Our results indicate that shock velocity in AGNs can not be estimated using standard optical line ratio diagrams, based on integrated spectra. Our models predict a different temperature structure and O+/O and O2+/O fractional abundances throughout the NLR clouds than those derived from pure photoionization models, mainly in shock-dominated objects. This suggests that, in order to minimize the shock effects, the combination of emission-lines emitted by ions with similar intermediate ionization potential could be good metallicity indicators. Finally, we derive two calibrations between the N/O abundance ratio and the N2O2=log([N II]6584/[O II]3727) and N2=log([N II]6584/H{\\alpha}) indexes which agree with that derived from pure photoionization models.

We present a detailed analysis of all the X-ray data taken by the XMM-Newton satellite of a small sample of five Seyfert 1 galaxies: ESO 359-G19, HE 1143-1810, CTS A08.12, Mkn 110, and UGC 11763. Our aim is to characterize the different components of the material that print the absorption and emission features in the X-ray spectra of these objects. The continuum emission was studied through the EPIC spectra taking advantage of the spectral range of these cameras. The high resolution RGS spectra were analyzed in order to characterize the absorbing features and the emission line features that arise in the spectra of these sources.

For the first time, neon abundance has been derived in the narrow line region from a sample of Seyfert~2 nuclei. In view of this, we compiled from the literature fluxes of optical and infrared (IR) narrow emission lines for 35 Seyfert 2 nuclei in the local universe (\\(z < 0.06\\)). The relative intensities of emission lines were used to derive the ionic and total neon and oxygen abundances through electron temperature estimations (\\(T_e\\)-method). For the neon, abundance estimates were obtained by using both \\(T_e\\)-method and IR-method. Based on photoionization model results, we found a lower electron temperature [\\(t_e([Ne III])\\)] for the gas phase where the Ne\\(^2+\\) is located in comparison with \\(t_3\\) for the O\\(^2+\\) ion. We find that the differences (D) between Ne\\(^2+\\)/H\\(^+\\) ionic abundances calculated from IR-method and \\(T_e-\\)method (assuming \\(t_3\\) in the Ne\\(^2+\\)/H\\(^+\\) derivation) are similar to the derivations in star-forming regions (SFs) and they are reduced by a mean factor of \\(3\\) when \\(t_e([Ne III])\\) is considered. We propose a semi-empirical Ionization Correction Factor (ICF) for the neon, based on [Ne II]12.81\\(\\)m, [ıonNeiii]15.56\\(\\)m and oxygen ionic abundance ratios. We find that the average Ne/H abundance for the Seyfert 2s sample is nearly 2 times higher than similar estimate for SFs. Finally, for the very high metallicity regime (i.e. [\\(12+log(O/H) > 8.80\\)]) an increase in Ne/O with O/H is found, which likely indicates secondary stellar production for the neon.

We investigate the discrepancy between oxygen abundance estimations for narrow-line regions (NLRs) of Active Galactic Nuclei (AGNs) type Seyfert 2 derived by using direct estimations of the electron temperature (Te-method) and those derived by using photoionization models. In view of this, observational emission-line ratios in the optical range (3000 < \\lambda(\\AA) < 7000) of Seyfert 2 nuclei compiled from the literature were reproduced by detailed photoionization models built with the Cloudy code. We find that the derived discrepancies are mainly due to the inappropriate use of the relations between temperatures of the low (t2) and high (t3) ionization gas zones derived for H II regions in AGN chemical abundance studies. Using a photoionization model grid, we derived a new expression for t2 as a function of t3 valid for Seyfert 2 nuclei. The use of this new expression in the AGN estimation of the O/H abundances based on Te-method produces O/H abundances slightly lower (about 0.2 dex) than those derived from detailed photoionization models. We also find that the new formalism for the Te-method reduces by about 0.4 dex the O/H discrepancies between the abundances obtained from strong emission-line calibrations and those derived from direct estimations.