Solid-phase extraction of vanadium(V) from teainfusions and wines on immobilized nanometer titanium dioxide followed by ICP-OES analysis

Nanosized titanium dioxide immobilized on silica gel was synthesized and used as fixedbed phase for V(V) pre-concentration, followed by inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis. Three different sorbents were prepared by sol\u2013gel method starting from a mixture of titanium isopropoxide, 2-propanol and water, and characterized by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM) and BET analysis. V(V), the most stable and toxic oxidation state of the element, present in water and beverages samples, was selectively sorbed, pre-concentrated, quantitatively eluted by 0.1 M HCl and analyzed by ICP-OES. The effectiveness of the procedure was first assessed on tap water enriched with 1 lg L1 of V(V) obtaining recoveries up to 92% (n= 4). The pre-concentration step was then optimized for complex matrices such as tea infusions and red and white wines. The reliability of the procedure was assessed on the same beverages samples spiked with 20\u2013250 lg L1. Quantitative recoveries (82\u2013 95%, n= 4) were assured avoiding any sample pre-treatment, generally essential in such complex matrices, obtaining good precision (RSD< 12%, n= 3). The method was then applied to the determination of V(V) in commercial tea infusions and wines

miR-21: an oncomir on strike in prostate cancer

<p>Abstract</p> <p>Background</p> <p>Aberrant expression of microRNAs, small non-coding RNA molecules that post-transcriptionally repress gene expression, seems to be causatively linked to the pathogenesis of cancer. In this context, miR-21 was found to be overexpressed in different human cancers (e.g. glioblastoma, breast cancer). In addition, it is thought to be endowed with oncogenic properties due to its ability to negatively modulate the expression of tumor-suppressor genes (e.g. <it>PTEN</it>) and to cause the reversion of malignant phenotype when knocked- down in several tumor models. On the basis of these findings, miR-21 has been proposed as a widely exploitable cancer-related target. However, scanty information is available concerning the relevance of miR-21 for prostate cancer. In the present study, we investigated the role of miR-21 and its potential as a therapeutic target in two prostate cancer cell lines, characterized by different miR-21 expression levels and <it>PTEN </it>gene status.</p> <p>Results</p> <p>We provide evidence that miR-21 knockdown in prostate cancer cells is not sufficient <it>per se </it>i) to affect the proliferative and invasive potential or the chemo- and radiosensitivity profiles or ii) to modulate the expression of the tumor-suppressors PTEN and Pdcd4, which in other tumor types were found to be regulated by miR-21. We also show that miR-21 is not differently expressed in carcinomas and matched normal tissues obtained from 36 untreated prostate cancer patients subjected to radical prostatectomy.</p> <p>Conclusions</p> <p>Overall, our data suggest that miR-21 is not a central player in the onset of prostate cancer and that its single hitting is not a valuable therapeutic strategy in the disease. This supports the notion that the oncogenic properties of miR-21 could be cell and tissue dependent and that the potential role of a given miRNA as a therapeutic target should be contextualized with respect to the disease.</p

Solid-phase extraction of vanadium (V) from tea infusions and wines on immobilized nanometer titanium dioxide followed by ICP-OES analysis

Abstract Nanosized titanium dioxide immobilized on silica gel was synthesized and used as fixed-bed phase for V (V) pre-concentration, followed by inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis. Three different sorbents were prepared by sol- gel method starting from a mixture of titanium isopropoxide, 2-propanol and water, and characterized by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM) and BET analysis

Sunlight-promoted photocatalytic hydrogen gas evolution from water-suspended cellulose: a systematic study

Abstract This work presents a systematic study of cellulose (CLS) as a sacrificial biomass for photocatalytic H2 evolution from water. The idea is indeed to couple a largely available and not expensive biomass, and water, with a renewable energy like solar radiation. An aqueous CLS suspension irradiated either at 366 nm (UV-A) or under sunlight in the presence of Pt/TiO2 behaves as a H2 evolving system. The effects of irradiation time, catalyst and CLS concentrations, pH and water salinity are studied. Addition of CLS to the sample significantly improved H2 evolution from water splitting, with yields up to ten fold higher than those observed in neat water. The mechanism of the photocatalytic process relies on the TiO2-mediated CLS hydrolysis, under irradiation. The polysaccharide depolymerisation generates water-soluble species and intermediates, among them 5-hydroxymethylfurfural (HMF) was identified. These intermediates are readily oxidized following the glucose photoreforming, thus enhancing water hydrogen ion reduction to give gas-phase H2. The formation of "colored" by-products from HMF self-polymerization involves a sort of "in situ dye sensitization" that allows an effective photoreaction even under solar light. The procedure is evaluated and successfully extended on cellulosic biomasses, i.e. rice husk and alfalfa (Medicago sativa) stems, not previously investigated for this application

TiO< sub> 2</sub>-modified zeolites for fluoroquinolones removal from wastewaters and reuse after solar light regeneration

Abstract Adsorption and photocatalytic removal from water of marbofloxacin (MAR) and enrofloxacin (ENR), two fluoroquinolone (FQ) antibiotics widely present in surface waters, were investigated on zeolite Y derivatized with three different TiO 2 catalysts (P25 Degussa and TiO 2 obtained by optimization of a sol\u2013gel method). The prepared materials were characterized by X-rays powder diffraction (XRPD), scanning electron microscopy (SEM), BET analysis and diffuse reflectance spectroscopy (DRS). TiO 2-derivatization improved .

LEADeR role of miR-205 host gene as long noncoding RNA in prostate basal cell differentiation

Though miR-205 function has been largely characterized, the nature of its host gene, MIR205HG, is still completely unknown. Here, we show that only lowly expressed alternatively spliced MIR205HG transcripts act as de facto pri-miRNAs, through a process that involves Drosha to prevent unfavorable splicing and directly mediate miR-205 excision. Notably, MIR205HG-specific processed transcripts revealed to be functional per se as nuclear long noncoding RNA capable of regulating differentiation of human prostate basal cells through control of the interferon pathway. At molecular level, MIR205HG directly binds the promoters of its target genes, which have an Alu element in proximity of the Interferon-Regulatory Factor (IRF) binding site, and represses their transcription likely buffering IRF1 activity, with the ultimate effect of preventing luminal differentiation. As MIR205HG functions autonomously from (albeit complementing) miR-205 in preserving the basal identity of prostate epithelial cells, it warrants reannotation as LEADeR (Long Epithelial Alu-interacting Differentiation-related RNA)