Influence of l-Dopa adsorption time and concentration on Au nanorods aggregation for SERS quantitative analysis

Oliveira Tatiana A.,Martin Cibely S.,Rubira Rafael J.G.,de Barros Anerise,Mazali Italo O.,Constantino Carlos J.L. 한국물리학회 2023 Current Applied Physics Vol.54 No.-

Levodopa (l-Dopa) is an important neurotransmitter from the amino acid family and is also associated with the treatment of Parkinson's disease. The obtention of the l-Dopa SERS signal in colloid is a challenge due to the zwitterionic charge promoting repulsion from nanoparticle surface and leading to poor or not active SERS signal. In this work, SERS signal of l-Dopa was successfully obtained using Au nanorods (AuNRs) covered with a cationic lipid bilayer and using the 785 nm laser line. The UV–Vis extinction, dynamic light scattering, and zeta potential results indicated an influence of l-Dopa adsorption time and l-Dopa concentration on AuNRs aggregation. The SERS signal followed this time dependence, being the characteristic l-Dopa band observed only after 30 min. The l-Dopa quantitative analysis using the standard addition method presented a linear SERS signal at 439 cm−1 with a limit of detection of 6.7 × 10−7 mol L−1 for peak intensity, and 7.9 × 10−7 mol L−1 for band integrated area.

Characterization of odourous compounds in air, leachate, stream and well in and around Taju-Bello Dumpsite, Lagos, Nigeria

Azeez, L.,Oyedeji, O.A.,Abdulsalami, I.O.,Adewuyi, S.O. Techno-Press 2013 Advances in environmental research Vol.2 No.2

This study investigated the concentrations of odourous compounds in air, leachate, stream and well in and around Taju-Bello dumpsite. Meteorological parameters (temperature, relative humidity, wind velocity) and six odour families comprising sulphur ($H_2S$), ammonia ($NH_3$), aromatic (benzene, toluene, ethylbenzene, styrene, p-xylene, m-xylene), aliphatic (hexane), oxygenated (formaldehyde, acetaldehyde) and halogenated (tetrachloroethene, trichloroethene, carbontetrachloride) compounds were measured. Meteorological parameters suggested low dispersal of pollutants at L1 with possible perspiration and suffocation from exposure to high temperature, relative humidity and low wind velocity. The trend of abundance of odourous compounds at studied locations is of the order dumpsite (L1) > leachate (L4) > 100 m away from dumpsite (L2) > 200 m away from dumpsite (L3) > stream (L5) > well (L6). $H_2S$, Oxygenated and aromatic compounds were the major contributors to odour strength in these locations. Correlation, factor and cluster analyses of the data revealed similarities of sources as biogenics and xenobiotics inherent in the wastes as the main sources of these odourous compounds.

Natural Products from Garcinia brasiliensis as Leishmania Protease Inhibitors

Ivan O. Pereira,Diego M. Assis,Maria A. Juliano,Rodrigo L.O.R. Cunha,Clara L. Barbieri,Luis V.S. do Sacramento,Marcos J. Marques,Marcelo H. dos Santos 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.6

The infections by protozoans of the genus Leishmania are a major worldwide health problem, with high endemicity in developing countries. The drugs of choice for the treatment of leishmaniasis are the pentavalent antimonials, which cause renal and cardiac toxicity. As part of a search for new drugs against leishmaniasis, we evaluated the in vitro Leishmania protease inhibition activity of extracts (hexanic, ethyl-acetate, and ethanolic) and fukugetin, a bioflavonoid purified from the ethyl-acetate extract of the pericarp of the fruit of Garcinia brasiliensis, a tree native to Brazilian forests. The isolated compound was characterized by using spectral analyses with nuclear magnetic resonance, mass spectroscopy, ultraviolet, and infrared techniques. The ethyl-acetate extract and the compound fukugetin showed significant activity as inhibitors of Leishmania's proteases, with mean (±SD) IC50 (50% inhibition concentration of protease activity) values of 15.0±1.3 μg/mL and 3.2±0.5 μM/mL, respectively, characterizing a bioguided assay. In addition, this isolated compound showed no activity against promastigote and amastigote forms of L. (L.) amazonensis and mammalian cells. These results suggest that fukugetin is a potent protease inhibitor of L. (L.) amazonensis and does not cause toxicity in mammalian or Leishmania cells in vitro. This study provides new perspectives on the development of novel drugs that have leishmanicidal activity obtained from natural products and that target the parasite's proteases.

The effect of Sn on the electronic state of M/γ-Al₂O₃(M = Pd, Pt) catalysts and the influence in the catalytic combustion of methane

Grisel Corro,O. Vázquez-Cuchillo,F. Bañuelos,A. Cruz-López,J.L.G. Fierro 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.6

Pd-Sn and Pt-Sn catalysts supported on γ-Al2O3 were prepared by co-precipitation and the Pt characterized dispersion of reduced samples was determined by H2 chemisorption for Pt and Pt-Sn catalysts, The Pd dispersion was determined by CO adsorption on Pd and Pd-Sn catalysts. The catalysts were characterized by the electron binding energy values determined by XPS. The results are explained on the basis of the Pt and Pd species electron binding energy changes due to the electronic properties of Sn. The catalytic activity in methane oxidation under lean burn conditions was measured. The results reveal that the tin addition causes a change in the catalytic activity of the supported catalysts, showing a greater catalytic activity on the CH4-O2 reaction for the bimetallic Pd-Sn/ γ-Al2O3. Pd-Sn and Pt-Sn catalysts supported on γ-Al2O3 were prepared by co-precipitation and the Pt characterized dispersion of reduced samples was determined by H2 chemisorption for Pt and Pt-Sn catalysts, The Pd dispersion was determined by CO adsorption on Pd and Pd-Sn catalysts. The catalysts were characterized by the electron binding energy values determined by XPS. The results are explained on the basis of the Pt and Pd species electron binding energy changes due to the electronic properties of Sn. The catalytic activity in methane oxidation under lean burn conditions was measured. The results reveal that the tin addition causes a change in the catalytic activity of the supported catalysts, showing a greater catalytic activity on the CH4-O2 reaction for the bimetallic Pd-Sn/ γ-Al2O3.

DHS-21, a dicarbonyl/l-xylulose reductase (DCXR) ortholog, regulates longevity and reproduction in Caenorhabditis elegans

Son, L.T.,Ko, K.M.,Cho, J.H.,Singaravelu, G.,Chatterjee, I.,Choi, T.W.,Song, H.O.,Yu, J.R.,Park, B.J.,Lee, S.K.,Ahnn, J. North-Holland Pub ; Elsevier Science Ltd 2011 FEBS letters Vol.585 No.9

Dicarbonyl/l-xylulose reductase (DCXR) converts l-xylulose into xylitol, and reduces various α-dicarbonyl compounds, thus performing a dual role in carbohydrate metabolism and detoxification. In this study, we identified DHS-21 as the only DCXR ortholog in Caenorhabditis elegans. The dhs-21 gene is expressed in various tissues including the intestine, gonadal sheath cells, uterine seam (utse) cells, the spermathecal-uterus (sp-ut) valve and on the plasma membrane of spermatids. Recombinant DHS-21 was shown to convert l-xylulose to xylitol using NADPH as a cofactor. Dhs-21 null mutants of C. elegans show defects in longevity, reproduction and egg-laying. Knock-down of daf-16 and elt-2 transcription factors affected dhs-21 expression. These results suggest that DHS-21 is a bona fide DCXR of C. elegans, essential for normal life span and reproduction.

Crystal structure and second harmonic generation in Bi₂TeO₅: An X-N study from synchrotron and neutron diffraction data

Ló,pez, C.A.,Bâ,ati, E.,Ferná,ndez-Dí,az, M.T.,Saouma, F.O.,Jang, J.I.,Alonso, J.A. Academic Press 2019 Journal of solid state chemistry Vol.276 No.-

<P><B>Abstract</B></P> <P>Bi<SUB>2</SUB>TeO<SUB>5</SUB> has been obtained in polycrystalline form via solid state reaction and structurally characterized from both synchrotron and neutron powder diffraction data, enabling the precise determination of the atomic positions. The crystal structure is defined in the acentric <I>Amb</I>2 space group, containing three crystallographically unequivalent Bi atoms. The position of the stereochemically active electron lone pairs of both Bi<SUP>3+</SUP> and Te<SUP>4+</SUP> ions is inferred to be opposite to the strongly covalent BiO and TeO chemical bonds; the global electron polarization arises from the non-compensated Bi<SUP>3+</SUP> lone electron pairs. Additionally, from difference Fourier maps between synchrotron and neutron diffraction data (X-N technique) it was possible to observe experimental evidence of the lone electron pair for Bi<SUP>3+</SUP>. Nonlinear optical measurements display highly active second harmonic generation response, comparable to that of reference AgGaSe<SUB>2</SUB>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The crystal structure is defined in the non-centrosymmetric <I>Amb</I>2 space group. </LI> <LI> Fourier maps between synchrotron and neutron diffraction data (X-N technique). </LI> <LI> Experimental evidence of Bi<SUP>3+</SUP>lone electron pair from X-N study. </LI> <LI> Nonlinear optical measurements display highly active SHG response. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Global emissions of HFC-143a (CH3CF3) and HFC-32 (CH2F2) from in situ and air archive atmospheric observations

O&,apos,Doherty, S.,Rigby, M.,Mü,hle, J.,Ivy, D. J.,Miller, B. R.,Young, D.,Simmonds, P. G.,Reimann, S.,Vollmer, M. K.,Krummel, P. B.,Fraser, P. J.,Steele, L. P.,Dunse, B.,Salameh, P. K.,Harth, Copernicus GmbH 2014 Atmospheric chemistry and physics Vol.14 No.17

<P>Abstract. High-frequency, in situ observations from the Advanced Global Atmospheric Gases Experiment (AGAGE), for the period 2003 to 2012, combined with archive flask measurements dating back to 1977, have been used to capture the rapid growth of HFC-143a (CH3CF3) and HFC-32 (CH2F2) mole fractions and emissions into the atmosphere. Here we report the first in situ global measurements of these two gases. HFC-143a and HFC-32 are the third and sixth most abundant hydrofluorocarbons (HFCs) respectively and they currently make an appreciable contribution to the HFCs in terms of atmospheric radiative forcing (1.7 ± 0.04 and 0.7 ± 0.02 mW m−2 in 2012 respectively). In 2012 the global average mole fraction of HFC-143a was 13.4 ± 0.3 ppt (1σ) in the lower troposphere and its growth rate was 1.4 ± 0.04 ppt yr−1; HFC-32 had a global mean mole fraction of 6.2 ± 0.2 ppt and a growth rate of 1.1 ± 0.04 ppt yr−1 in 2012. The extensive observations presented in this work have been combined with an atmospheric transport model to simulate global atmospheric abundances and derive global emission estimates. It is estimated that 23 ± 3 Gg yr−1 of HFC-143a and 21 ± 11 Gg yr−1 of HFC-32 were emitted globally in 2012, and the emission rates are estimated to be increasing by 7 ± 5% yr−1 for HFC-143a and 14 ± 11% yr−1 for HFC-32. </P>

Characterization and application of a coating of starch extracted from avocado (Persea americana L. cv. Hass) seeds as an alternative to reduce acrylamide content in French fries

O. Vega-Castro,M. Ramírez,L. Blandón-Mena,J. Contreras-Calderón,M. Mesías,C. Delgado-Andrade,F. J. Morales,D. Granda-Restrepo 한국식품과학회 2022 Food Science and Biotechnology Vol.31 No.12

The starch extracted from avocado (Persea americana L. cv. Hass) seeds was characterized and used in the preparation of an edible coating to reduce the oil uptake and acrylamide content in French fries. Starch characterization was carried out using Differential Scanning Calorimetry, Fourier transform infrared spectrophotometry, gelatinization, and scanning electron microscopy. Uncoated (UFF) and coated (CFF) French fries were compared and evaluated for moisture, water activity (Aw), fat, color, firmness, acrylamide content, and sensorial analysis. The extracted starch presented a high crystalline structure and good stability to mechanical work and heat treatments. The CFF French fries showed significantly higher Aw, color parameter a*, but lower luminosity and acrylamide content than UFF samples. Similarly, the CFF samples tended to decrease the fat content, although without statistical differences. Avocado seed starch can be an economical and technically feasible alternative to the food industry as an effective coating to reduce acrylamide content in French fries.

PRPF8 increases the aggressiveness of hepatocellular carcinoma by regulating FAK/AKT pathway via fibronectin 1 splicing

López-Cánovas Juan L.,Hermán-Sánchez Natalia,del Rio-Moreno Mercedes,Fuentes-Fayos Antonio C.,Lara-López Araceli,Sánchez-Frias Marina E.,Amado Víctor,Ciria Rubén,Briceño Javier,de la Mata Manuel,Casta 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Hepatocellular carcinoma (HCC) pathogenesis is associated with alterations in splicing machinery components (spliceosome and splicing factors) and aberrant expression of oncogenic splice variants. We aimed to analyze the expression and potential role of the spliceosome component PRPF8 (pre-mRNA processing factor 8) in HCC. PRPF8 expression (mRNA/protein) was analyzed in a retrospective cohort of HCC patients (n = 172 HCC and nontumor tissues) and validated in two in silico cohorts (TCGA and CPTAC). PRPF8 expression was silenced in liver cancer cell lines and in xenograft tumors to understand the functional and mechanistic consequences. In silico RNAseq and CLIPseq data were also analyzed. Our results indicate that PRPF8 is overexpressed in HCC and associated with increased tumor aggressiveness (patient survival, etc.), expression of HCC-related splice variants, and modulation of critical genes implicated in cancer-related pathways. PRPF8 silencing ameliorated aggressiveness in vitro and decreased tumor growth in vivo. Analysis of in silico CLIPseq data in HepG2 cells demonstrated that PRPF8 binds preferentially to exons of protein-coding genes, and RNAseq analysis showed that PRPF8 silencing alters splicing events in multiple genes. Integrated and in vitro analyses revealed that PRPF8 silencing modulates fibronectin (FN1) splicing, promoting the exclusion of exon 40.2, which is paramount for binding to integrins. Consistent with this finding, PRPF8 silencing reduced FAK/AKT phosphorylation and blunted stress fiber formation. Indeed, HepG2 and Hep3B cells exhibited a lower invasive capacity in membranes treated with conditioned medium from PRPF8-silenced cells compared to medium from scramble-treated cells. This study demonstrates that PRPF8 is overexpressed and associated with aggressiveness in HCC and plays important roles in hepatocarcinogenesis by altering FN1 splicing, FAK/AKT activation and stress fiber formation.

Three‐dimensional Simulations of MHD Jet Propagation through Uniform and Stratified External Environments

O’Neill, S. M.,Tregillis, I. L.,Jones, T. W.,Ryu, Dongsu IOP Publishing 2005 The Astrophysical journal Vol.633 No.2