A novel way to facilely degrade organic pollutants with the tail-gas derived from PHP (phosphoric acid plus hydrogen peroxide) pretreatment of lignocellulose.

The abundantly released tail-gas from lignocellulose pretreatment with phosphoric acid plus hydrogen peroxide (PHP) was found to accelerate the aging of latex/silicone textural accessories of the pretreatment device. Inspired by this, tail-gas was utilized to control organic pollutants. Methylene blue (MB), as a model pollutant, was rapidly decolorized by the tail-gas, and oxidative degradation was substantially proven by full-wavelength scanning with a UV-visible spectrometer. The tail-gas from six typical lignocellulosic feedstocks produced 68.0-98.3% MB degradation, suggesting its wide feedstock compatibility. Three other dyes, including rhodamine B, methyl orange and malachite green, obtained 97.5-99.5% degradation; moreover, tetracycline, resorcinol and hexachlorobenzene achieved 73.8-93.7% degradation, suggesting a superior pollutant compatibility. In a cytotoxicity assessment, the survival rate of the degraded MB was 103.5% compared with 80.4% for the untreated MB, implying almost no cytotoxicity after MB degradation. Mechanism investigations indicated that the self-exothermic reaction in PHP pretreatment drove the self-generated peroxy acids into tail-gas. Moreover, it heated the pollutant solution and thermally activated peroxy acids as free radicals for efficient pollutant degradation. Here, a brand-new technique for degrading organic pollutants with a "Win-Win-Win" concept was purposed for lignocellulose valorization, pollutant control by waste tail-gas, and biofuel production.

Self-assembled nanostructures of phosphomolybdate, nucleobase and metal ions synthesis and their in vitro cytotoxicity studies on cancer cell lines.

The ability of the multidentate nucleobases, adenine and thymine, to coordinate polyoxometalate and metal ions leading to the formation of self-assembled nanostructures and their strong cytotoxicity toward cancer cell lines have been demonstrated. A unique synthetic approach is developed to make a series of functional nanoscale hybrid materials consisting of nucleobases (adenine and thymine) and phosphomolybdic acid (PMA) through solid state chemical reaction and self-assembly process. Adenine was protonated through its ring nitrogen, while the ketone group in thymine was protonated during the addition of PMA to these nucleobases. The self-assembled nanostructures formed as a result of the electrostatic interaction between the protonated nucleobases and polyanionic PMA. To promote the base pairing between the nucleobases, chloroaurate ions and silver ions were added to each PMA/adenine and PMA/thymine nanostructures. The complexation between the nucleobases and the added metal ions was found to drive the formation of subsequent self-assembled nanostructures. All the materials were screened for their anticancer activity against breast (MDAMB-231) and prostate (PC-3) cancer cells, and non-cancerous keratinocyte cells HaCaT. PMA/adenine/[AuCl4]- and PMA/thymine/Ag+ nanostructures were found to have strong anti-cancer activity, while PMA/adenine/Ag+, PMA/thymine/[AuCl4]-, and PMA/pdenine, PMA/thymine nanostructures did not exhibit such activity. The unique redox properties of these materials and the self-assembly of the PMA and metal ions were the major factors responsible for the cytotoxicity. This unique approach of making functional nanomaterials incorporate the nucleobase, PMA and metal ions using solid state self-assembly and their anti-cancer applications are considered to be an effective approach for the development of inorganic nucleoside analogue bio-pharmaceutical agents.

Polyphosphoric acid capping radioactive/upconverting NaLuF4:Yb,Tm,153Sm nanoparticles for blood pool imaging in vivo.

Nanoparticles that circulate in the bloodstream for a prolonged period of time have important biomedicine applications. However, no example of lanthanide-based nanoparticles having a long-term circulation bloodstream has been reported to date. Herein, we report on difunctional radioactive and upconversion nanoparticles (UCNP) coated with polyphosphoric acid ligand, that is ethylenediamine tetramethylenephosphonic acid (EDTMP), for an application in single-photon emission computed tomography (SPECT) blood pool imaging. The structure, size and zeta-potential of the EDTMP-coated nanoparticles (EDTMP-UCNP) are verified using transmission electron microscopy and dynamic light scattering. Injection of radioisotope samarium-153-labeled EDTMP-UCNP (EDTMP-UCNP:(153)Sm) into mice reveal superior circulation time compared to control nanoparticles coated with citric acid (cit-UCNP:(153)Sm) and (153)Sm complex of EDTMP (EDTMP-(153)Sm). The mechanism for the extended circulation time may be attributed to the adhesion of EDTMP-UCNP on the membrane of red blood cells (RBCs). In vivo toxicity results show no toxicity of EDTMP-UCNP at the dose of 100 mg/kg, validating its safety as an agent for blood pool imaging. Our results provide a new strategy of nanoprobe for a long-term circulation bloodstream by introducing polyphosphoric acid as surface ligand.

Radionuclide concentrations in raw and purified phosphoric acids from Brazil and their processing wastes: implications for radiation exposures.

Radionuclides from the U and Th natural series are present in alkaline rocks, which are used as feedstock in Brazil for the production of raw phosphoric acid, which can be considered as a NORM (naturally occurring radioactive material). As a result of the purification of raw phosphoric acid to food-grade phosphoric acid, two by-products are generated, i.e., solid and liquid wastes. Taking this into account, the main aim of this study was to evaluate the fluxes of natural radionuclide in the production of food-grade phosphoric acids in Brazil, to determine the radiological impact caused by ingestion of food-grade phosphoric acid, and to evaluate the solid waste environmental hazards caused by its application in crop soils. Radiological characterization of raw phosphoric acid, food-grade phosphoric acid, solid waste, and liquid waste was performed by alpha and gamma spectrometry. The (238)U, (234)U, (226)Ra, and (232)Th activity concentrations varied depending on the source of raw phosphoric acid. Decreasing radionuclides activity concentrations in raw phosphoric acids used by the producer of the purified phosphoric acid were observed as follows: Tapira (raw phosphoric acid D) > Catalão (raw phosphoric acids B and C) > Cajati (raw phosphoric acid A). The industrial purification process produces a reduction in radionuclide activity concentrations in food-grade phosphoric acid in relation to raw phosphoric acid produced in plant D and single raw phosphoric acid used in recent years. The most common use of food-grade phosphoric acid is in cola soft drinks, with an average consumption in Brazil of 72 l per person per year. Each liter of cola soft drink contains 0.5 ml of food-grade phosphoric acid, which gives an annual average intake of 36 ml of food-grade phosphoric acid per person. Under these conditions, radionuclide intake through consumption of food-grade phosphoric acid per year per person via cola soft drinks is not hazardous to human health in Brazil. Considering these annual additions of (238)U, (226)Ra, (232)Th and (40)K, and since these radionuclide should be homogeneously distributed in the upper 10 cm of soils with an assumed apparent density of 1.5 g/cm(3), a maximum increase of 0.19 ± 0.03 Bq kg(-1) of soil is expected for (238)U and (234)U. Thus, the addition of solid waste as phosphate fertilizers to Brazilian agricultural soils does not represent a hazard to the ecosystem or to human health.

Phosphoramidate prodrugs of 2'-C-methylcytidine for therapy of hepatitis C virus infection.

The application of a phosphoramidate prodrug approach to 2'-C-methylcytidine (NM107), the first nucleoside inhibitor of the hepatitis C virus (HCV) NS5B polymerase, is reported. 2'-C-Methylcytidine, as its valyl ester prodrug (NM283), was efficacious in reducing the viral load in patients infected with HCV. Several of the phosphoramidates prepared demonstrated a 10- to 200-fold superior potency with respect to the parent nucleoside in the cell-based replicon assay. This is due to higher levels of 2'-C-methylcytidine triphosphate in the cells. These prodrugs are efficiently activated and converted to the triphosphate in hepatocytes of several species. Our SAR studies ultimately led to compounds that gave high levels of NTP in hamster and rat liver after subcutaneous dosing and that were devoid of the toxic phenol moiety usually found in ProTides.