The SUPERCOLD-CGM survey: \\ I. Probing the extended CO(4-3) Emission of the Circumglactic medium in a sample of 10 Enormous Lyα\alpha Nebulae at z∼2z\sim2

To understand how massive galaxies at high-$z$ co-evolve with enormous reservoirs of halo gas, it is essential to study the coldest phase of the circum-galactic medium (CGM), which directly relates to stellar growth. The SUPERCOLD-CGM survey is the first statistical survey of cold molecular gas on CGM scales. We present ALMA+ACA observations of CO(4-3) and continuum emission from 10 Enormous Ly$\alpha$ Nebula (ELANe) around ultraluminous type-I QSOs at $z\sim2$. We detect CO(4-3) in 100$\%$ of our targets, with 60$\%$ showing extended CO on scales of 15$-$100 kpc. Q1228+3128 reveals the most extended CO(4-3) reservoir of $\sim$100 kpc and is the only radio-loud target in our sample. The CO reservoir is located along the radio axis, which could indicate a link between the inner radio-jet and cold halo gas. For the other five radio-quiet ELANe, four of them show extended CO(4-3) predominantly in the direction of their companions. These extended CO(4-3) reservoirs identify enrichment of the CGM, and may potentially contribute to widespread star formation. However, there is no evidence from CO(4-3) for diffuse molecular gas spread across the full extent of the Ly$\alpha$ nebulae. One target in our sample (Q0107) shows significant evidence for a massive CO disk associated with the QSO. Moreover, 70$\%$ of our QSO fields contain at least one CO companion, two of which reveal extended CO emission outside the ELANe. Our results provide insight into roles of both the cold CGM and companions in driving the early evolution of massive galaxies.Comment: Accepted for publication in ApJ. 27 pages, 16 figure

Threat of allergenic airborne grass pollen in Szczecin, NW Poland: the dynamics of pollen seasons, effect of meteorological variables and air pollution

The dynamics of Poaceae pollen season, in particularly that of the Secale genus, in Szczecin (western Poland) 2004–2008 was analysed to establish a relationship between the meteorological variables, air pollution and the pollen count of the taxa studied. Consecutive phases during the pollen season were defined for each taxon (1, 2.5, 5, 25, 50, 75, 95, 97.5, 99% of annual total), and duration of the season was determined using the 98% method. On the basis of this analysis, the temporary differences in the dynamics of the seasons were most evident for Secale in 2005 and 2006 with the longest main pollen season (90% total pollen). The pollen season of Poaceae started the earliest in 2007, when thermal conditions were the most favourable. Correlation analysis with meteorological factors demonstrated that the relative humidity, mean and maximum air temperature, and rainfall were the factors influencing the average daily pollen concentrations in the atmosphere; also, the presence of air pollutants such as ozone, PM10 and SO2 was statistically related to the pollen count in the air. However, multiple regression models explained little part of the total variance. Atmospheric pollution induces aggravation of symptoms of grass pollen allergy

Dynamically Reversible Iron Oxide Nanoparticle Assemblies for Targeted Amplification of T1-Weighted Magnetic Resonance Imaging of Tumors

Smart magnetic resonance (MR) contrast agents, by which MR contrast can be selectively enhanced under acidic tumor microenvironment, are anticipated to significantly improve the diagnostic accuracy. Here, we report pH-sensitive iron oxide nanoparticle assemblies (IONAs) that are cross-linked by small-molecular aldehyde derivative ligands. The dynamic formation and cleavage of hydrazone linkages in neutral and acidic environments, respectively, allow the reversible response of the nanoassemblies to pH variations. At neutral pH, IONAs are structurally robust due to the cross-linking by the strong hydrazone bonds. In acidic tumor microenvironment, the hydrazone bonds are cleaved so that the IONAs are quickly disassembled into a large number of hydrophilic extremely small-sized iron oxide nanoparticles (ESIONs). As a result, significantly enhanced T1MR contrast is achieved, as confirmed by the measurement of r1 values at different pH conditions. Such acidity-targeting MR signal amplification by the pH-sensitive IONAs was further validated in vivo, demonstrating a novel T1 magnetic resonance imaging (MRI) strategy for highly sensitive imaging of acidic tumors. Copyright © 2019 American Chemical Society11sciescopu

Genome-wide DNA methylation profiling reveals cancer-associated changes within early colonic neoplasia.

Colorectal cancer (CRC) is characterized by genome-wide alterations to DNA methylation that influence gene expression and genomic stability. Less is known about the extent to which methylation is disrupted in the earliest stages of CRC development. In this study, we have combined laser-capture microdissection with reduced representation bisulfite sequencing to identify cancer-associated DNA methylation changes in human aberrant crypt foci (ACF), the earliest putative precursor to CRC. Using this approach, methylation profiles have been generated for 10 KRAS-mutant ACF and 10 CRCs harboring a KRAS mutation, as well as matched samples of normal mucosa. Of 811 differentially methylated regions (DMRs) identified in ACF, 537 (66%) were hypermethylated and 274 (34%) were hypomethylated. DMRs located within intergenic regions were heavily enriched for AP-1 transcription factor binding sites and were frequently hypomethylated. Furthermore, gene ontology analysis demonstrated that DMRs associated with promoters were enriched for genes involved in intestinal development, including homeobox genes and targets of the Polycomb repressive complex 2. Consistent with their role in the earliest stages of colonic neoplasia, 75% of the loci harboring methylation changes in ACF were also altered in CRC samples, though the magnitude of change at these sites was lesser in ACF. Although aberrant promoter methylation was associated with altered gene expression in CRC, this was not the case in ACF, suggesting the insufficiency of methylation changes to modulate gene expression in early colonic neoplasia. Altogether, these data demonstrate that DNA methylation changes, including significant hypermethylation, occur more frequently in early colonic neoplasia than previously believed, and identify epigenomic features of ACF that may provide new targets for cancer chemoprevention or lead to the development of new biomarkers for CRC risk. Oncogene 2017 Aug 31; 36(35):5035-5044

Toxicological Risk Assessments of Iron Oxide Nanocluster- and Gadolinium-Based T1MRI Contrast Agents in Renal Failure Rats

© 2019 American Chemical Society.Gadolinium-based contrast agents (GBCAs) are widely used for T1-weighted magnetic resonance imaging (MRI) in clinic diagnosis. However, a major drawback of GBCAs is that they can increase the toxicological risk of nephrogenic systemic fibrosis (NSF) in patients with advanced renal dysfunction. Hence, safer alternatives to GBCAs are currently in demand, especially for patients with renal diseases. Here we investigated the potential of polyethylene glycol (PEG)-stabilized iron oxide nanoclusters (IONCs) as biocompatible T1MRI contrast agents and systematically evaluated their NSF-related risk in rats with renal failure. We profiled the distribution, excretion, histopathological alterations, and fibrotic gene expressions after administration of IONCs and GBCAs. Our results showed that, compared with GBCAs, IONCs exhibited dramatically improved biosafety and a much lower risk of causing NSF, suggesting the feasibility of substituting GBCAs with IONCs in clinical MRI diagnosis of patients with renal diseases11sci