Comparison among composite methods on the calculation of proton and electron affinities in molecular systems

The CBS-4M, CBS-QB3, G2, G2(MP2), G3 and G3(MP2) model chemistry methods have been used to calculate proton and electron affinities for a set of molecular and atomic systems. Agreement with the experimental value for these electronic properties is quite good considering the uncertainty in the experimental data. A comparison among the six theories using statistical analysis (average value, standard deviation and root-mean-square) showed a better performance of CBS-QB3 to obtain these properties.195202Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Comparação entre métodos compostos no cálculo de afinidades por próton e elétron em sistemas moleculares

The CBS-4M, CBS-QB3, G2, G2(MP2), G3 and G3(MP2) model chemistry methods have been used to calculate proton and electron affinities for a set of molecular and atomic systems. Agreement with the experimental value for these electronic properties is quite good considering the uncertainty in the experimental data. A comparison among the six theories using statistical analysis (average value, standard deviation and root-mean-square) showed a better performance of CBS-QB3 to obtain these properties

Filamentous fungi in drinking water tanks of a water supply system in Recife-PE, Brazil

Drinking water reservoirs are widely used in various building constructions in Brazil for as a source of potable water for users. However, they are susceptible to the growth of microorganisms such as fungi. From these, several negative factors may ensue, namely, unpleasant odors and flavours, pigments, biofilm formation and mycotoxins. This is caused fungal resistance to treatment and disinfection. Brazilian law and those of other countries offer no encouragement for the research of the species of fungi that cause these problems. There are no legal limits as to the presence in drinking water. This study assesses the occurrence of filamentous fungi in drinking water reservoirs connected to the Alto do Céu distribution system located in Recife, Pernambuco, Brazil. Four monthly collections were carried out, in triplicate, at two fixed points in the network, at the same treatment area, and another 2.0 km away from this site. For water physicochemical characterization at the time of collection, pH, temperature and free residual chlorine were analyzed. Filamentous fungi were quantified by filtration through cellulose nitrate membrane with a 0.45 μm porosity. All strains were grown in Petri dishes containing Peptone Glucose, Rose Bengal Agar (PGRBA) and were incubated at 30°C for 48h. Fungal occurrence was quantified as colony forming units (CFU) per litre. Twenty-four samples were analyzed, and these accounted for 807 CFU. Considering the potential for water spreading diseases, and the high toxicity of fungi into account it is intended that this work may prompt the creation of acceptable parameters as to the presence of fungi in drinking water networks

Filamentous fungi in biofilms of water tanks in a supply system in Recife-PE, Brazil

Fungi cause detrimental organoleptic effects in water, and their presence may facilitate the occurrence of infections, allergic reactions and harmful effects from mycotoxins. Despite the lack of knowledge on the biological structure of filamentous fungi in biofilms, it is known that they can contribute with bacteria, yeasts, protozoa and viruses. Hence, this study analyzed, in situ, filamentous fungi in biofilms found in drinking water reservoirs of the distribution network in Alto do Céu, Recife, Pernambuco, Brazil. Biofilms were collected, in triplicate from samplers consisting of a polyethylene plate (4.0cm x 1.5cm) established in drinking water reservoirs. Four monthly collections were carried out between August and November 2011 at two fixed points. Polyethylene samplers were taken to the laboratory and washed with sterile water and transferred to Petri dishes containing medium Peptone, Glucose, Rose Bengal Agar (PGRBA). The plates were incubated at 30°C for 48h. The occurrence of fungi was reported as CFU/L. Fifty three colony forming units of fungi were quantified. For water physicochemical characterization at the time of collection, pH, temperature and free residual chlorine were analyzed. For detection of biofilms, a combination of two fluorescent techniques was used: (A) Fluorescent “in situ” hybridization (FISH) using a rDNA universal probe EUK516 (ACCAGACTTGCCCTCC 5’-3’, MWG Biotech, Ebersberg, Germany) labeled with cyanine Cy3 at the 5’ end and (B) Calcofluor White M2R (CW). After FISH and CW, the samples were observed under an epifluorescent microscope. Fungal filaments which formed biofilms in the distribution network were observed establishing biofilm formation. These results confirm the presence and relevance of filamentous fungi in structuring biofilms

Antibacterial activity of nitric oxide releasing silver nanoparticles

Silver nanoparticles (AgNPs) are well known potent antimicrobial agents. Similarly, the free radical nitric oxide (NO) has important antibacterial activity, and due to its instability, the combination of NO and nanomaterials has been applied in several biomedical applications. The aim of this work was to synthesize, characterize and evaluate the antibacterial activity of a new NO-releasing AgNPs. Herein, AgNPs were synthesized by the reduction of silver ions (Ag+) by catechin, a natural polyphenol and potent antioxidant agent, derived from green tea extract. Catechin acts as a reducing agent and as a capping molecule on the surface of AgNPs, minimizing particle agglomeration. The as-synthesized nanoparticles were characterized by different techniques. The results showed the formation of AgNPs with average hydrodynamic size of 44 nm, polydispersity index of 0.21, and zeta potential of -35.9 mV. X-ray diffraction and Fourier transform infrared spectroscopy revealed the presence of the AgNP core and cathecin as capping agent. The low molecular weight mercaptosuccinic acid (MSA), which contain free thiol group, was added on the surface of catechin-AgNPs, leading to the formation of MSA-catechin-AgNPs (the NO precursor nanoparticle). Free thiol groups of MSA-catechin-AgNPs were nitrosated leading to the formation of S-nitroso-mercaptosuccinic acid (S-nitroso-MSA), the NO donor. The amount of 342 +/- 16 mu mol of NO was released per gram of S-nitroso-MSA-catechin-AgNPs. The antibacterial activities of catechin-AgNPs, MSA-catechinAgNPs, and S-nitroso-MSA-catechin-AgNPs were evaluated towards different resistant bacterial strains. The results demonstrated an enhanced antibacterial activity of the NO-releasing AgNP. For instance, the minimal inhibitory concentration values for Pseudomonas aeruginosa (ATCC 27853) incubated with AgNPs-catechin, AgNPs-catechin-MSA, and AgNPs-catechin-S-nitroso-MSA were found to be 62, 125 and 3 mu g/mL, respectively. While in the case of Klebsiella pneumoniae (ATCC 700603) the minimum bactericidal concentration values for treatments with AgNPs-catechin, AgNPs-catechin-MSA, and AgNPs-catechin-Snitroso- MSA were found to be 1000, 500, and 125 mu g/mL, respectively. The antibacterial actions of the NO-releasing nanoparticle were superior in comparison with the antibacterial effects of AgNPs, in most of the tested antibiotic resistant bacteria strains. These results highlight the promising uses of NO-releasing AgNPs against resistant bacteria in several biomedical applications.Brazilian Network on Nanotoxicology (MCTI/CNPq)Laboratory of Nanostructure Synthesis and Biosystem Interactions-NANOBIOSS (MCTI)FONDECYTCONICYT REDESUniv Fed ABC, Ctr Nat & Human Sci, Santo Andre, SP, BrazilUniv Fed Sao Paulo, Exact & Earth Sci Dept, Diadema, SP, BrazilUniv La Frontera, Chem Engn Dept, Temuco, ChileUniv Estadual Campinas, Inst Biol, Trop Dis Lab, Campinas, SP, BrazilUniv Estadual Campinas, Biol Chem Lab, Inst Chem, Campinas, SP, BrazilLNNano CNPEM, Campinas, SP, BrazilUniv Fed Sao Paulo, Exact & Earth Sci Dept, Diadema, SP, BrazilBrazilian Network on Nanotoxicology (MCTI/CNPq): 552120/2011-1Laboratory of Nanostructure Synthesis and Biosystem Interactions-NANOBIOSS (MCTI): 402280-2013FONDECYT: 1130854CONICYT REDES: 140053Web of Scienc

In situ evaluation of fluoride-, stannous- and polyphosphate-containing solutions against enamel erosion

Objective To evaluate the anti-erosive effect of solutions containing sodium fluoride (F: 225 ppm of fluoride), sodium fluoride + stannous chloride (F + Sn: 225 ppm of fluoride + 800 ppm of stannous), sodium fluoride + stannous chloride + sodium linear polyphosphate (F + Sn + LPP: 225 ppm of fluoride + 800 ppm of stannous + 2% of sodium linear polyphosphate), and deionized water (C: control), using a four-phase, single-blind, crossover in situ clinical trial. Methods In each phase, 12 volunteers wore appliances containing 4 enamel specimens, which were submitted to a 5-day erosion-remineralization phase that consisted of 2 h of salivary pellicle formation with the appliance in situ, followed by 2 min extra-oral immersion in 1% citric acid (pH 2.4), 6x/day, with 90 min of exposure to saliva in situ between the challenges. Treatment with the test solutions was performed extra-orally for 2 min, 2x/day. At the end of the experiment, surface loss (SL, in μm) was evaluated by optical profilometry. Data were analyzed using ANOVA and Tukey tests (α = 0.05). The surface of additional specimens was evaluated by x-ray diffraction after treatments (n = 3). Results C (mean SL ± standard-deviation: 5.97 ± 1.70) and F (5.36 ± 1.59) showed the highest SL, with no significant difference between them (p > 0.05). F + Sn (2.68 ± 1.62) and F + Sn + LPP (2.10 ± 0.95) did not differ from each other (p > 0.05), but presented lower SL than the other groups (P < 0.05). Apatite and stannous deposits on specimen surfaces were identified in the x-ray analysis for F + Sn and F + Sn + LPP. Conclusions Sodium fluoride solution exhibited no significant anti-erosive effect. The combination between sodium fluoride and stannous chloride reduced enamel erosion, irrespective of the presence of linear sodium polyphosphate. Clinical significance Under highly erosive conditions, sodium fluoride rinse may not be a suitable alternative to prevent enamel erosion. A rinse containing sodium fluoride and stannous chloride was shown to be a better treatment option, which was not further improved by addition of the sodium linear polyphosphate

Discovery of a cluster of galaxies behind the Milky Way: X-ray and optical observations

We report the discovery of Cl 2334+48, a rich cluster of galaxies in the Zone of Avoidance, identified in public images from the XMM-Newton archive. We present the main properties of this cluster using the XMM-Newton X-ray data, along with new optical spectroscopic and photometric observations. Cl 2334+48 is located at z = 0.271 +/- 0.001, as derived from the optical spectrum of the brightest member galaxy. Such redshift agrees with a determination from the X-ray spectrum (z = 0.263 (+0.012/-0.010)), in which an intense emission line is matched to the rest wavelength of the Fe Kalpha complex. Its intracluster medium has a plasma temperature of 4.92 (+0.50/-0.48) keV, sub-solar abundance (0.38 +/- 0.12 Zsun), and a bolometric luminosity of 3.2 x 10^44 erg/s. A density contrast delta = 2500 is obtained in a radius of 0.5 Mpc/h70, and the corresponding enclosed mass is 1.5 x 10^14 Msun. Optical images show an enhancement of g'-i' > 2.5 galaxies around the central galaxy, as expected if these were cluster members. The central object is a luminous E-type galaxy, which is displaced ~ 40 kpc/h70 from the cluster X-ray center. In addition, it has a neighbouring arc-like feature (~ 22" or 90 kpc/h70 from it), probably due to strong gravitational lensing. The discovery of Cl 2334+48 emphasises the remarkable capability of the XMM-Newton to reveal new clusters of galaxies in the Zone of Avoidance.Comment: 9 pages, 11 figures, Accepted for publication in A&A (on July 12, 2006

Comparative chromosome painting discloses homologous Segments in distantly related mammals

Comparative chromosome painting, termed ZOO-FISH, using DNA libraries from flow sorted human chromosomes 1,16,17 and X, and mouse chromosome 11 discloses the presence of syntenic groups in distantly related mammalian Orders ranging from primates (Homo sapiens), rodents (Mus musculus), even-toed ungulates (Muntiacus muntjak vaginalis and Muntiacus reevesi) and whales (Balaenoptera physalus). These mammalian Orders have evolved separately for 55-80 million years (Myr). We conclude that ZOO-FISH can be used to generate comparative chromosome maps of a large number of mammalian species

Identification by MALDI-TOF MS of Sporothrix brasiliensis isolated from a subconjunctival infiltrative lesion in an immunocompetent patient

Sporotrichosis is a globally distributed subcutaneous fungal infection caused by dimorphic fungi belonging to the Sporothrix species complex that affects the skin of limbs predominantly, but not exclusively. A rare case of ocular sporotrichosis in an immunocompetent Brazilian patient from the countryside of Rio de Janeiro State is reported. A 68-year-old woman presented with a subconjunctival infiltrative lesion in the right eye with pre-auricular lymphadenopathy of onset 4 months ago that evolved to suppurative nodular lesions on the eyelids. Conjunctival secretion was evaluated by histopathological examination and inoculated on Sabouraud Dextrose Agar (SDA). Histopathology showed oval bodies within giant cells and other mononucleated histiocytes. Fungus grown on SDA was identified as Sporothrix sp. by morphological observations. The isolated strain was finally identified by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) associated with an in-house database enriched with reference Sporothrix complex spectra. The strain presented a MALDI spectrum with the ion peaks of the molecular mass profile of S. brasiliensis. The patient was adequately treated with amphotericin B subsequently replaced by itraconazole. Due to scars left by the suppurative process, the patient presented poor final visual acuity. The present work presents an overview of ocular sporotrichosis and discusses the diagnostic difficulty that can lead to visual sequelae in these cases.Financial support for this work by Fundação de Amparo à Pesquisa do Rio de Janeiro [FAPERJ] (Grants: INST E-26/010.001784/2016; JCNE E-26/203.301/2017), by Conselho Nacional de Desenvolvimento Científico e Tecnológico [CNPq] (Grant Proc. 409227/2016-1). This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES). MALDI-TOF MS analyses were partially developed using equipment funded by CONICYT/Chile through the project Fondequip EQM160054 2016. The Universidad de La Frontera (Temuco, Chile) partially funded this work through the Project DIUFRO PIA19-0001. Furthermore, this study was also supported by FCT under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Efficient fluorescence collection and ion imaging with the "tack" ion trap

Trapped, laser-cooled ions produce intense fluorescence. Detecting this fluorescence enables efficient measurement of quantum state of qubits based on trapped atoms. It is desirable to collect a large fraction of the photons to make the detection faster and more reliable. Additionally, efficient fluorescence collection can improve speed and fidelity of remote ion entanglement and quantum gates. Here we show a novel ion trap design that incorporates metallic spherical mirror as the integral part of the trap itself, being its RF electrode. The mirror geometry enables up to 35% solid angle collection of trapped ion fluorescence; we measure a 25% effective solid angle, likely limited by imperfections of the mirror surface. We also study properties of the images of single ions formed by the mirror and apply aberration correction. Owing to the simplicity of its design, this trap structure can be adapted for micro-fabrication and integration into more complex trap architectures.Comment: 9 pages, 6 figure