Effective separation of the actinides Am(III) and Cm(III) by electronic modulation of bis-(1,2,4-triazin-3-yl)phenanthrolines

It has been shown that modification of the phenanthroline backbone of CyMe4-BTPhen leads to subtle electronic modulation, permitting differential ligation of Am(III) and Cm(III) resulting in separation factors up to 7.

Hydrophilic sulfonated bis-1,2,4-triazine ligands are highly effective reagents for separating actinides(iii) from lanthanides(iii) via selective formation of aqueous actinide complexes

We report the first examples of hydrophilic 6,6′-bis(1,2,4-triazin-3-yl)-2,2′-bipyridine (BTBP) and 2,9-bis(1,2,4-triazin-3-yl)-1,10-phenanthroline (BTPhen) ligands, and their applications as actinide(III) selective aqueous complexing agents. The combination of a hydrophobic diamide ligand in the organic phase and a hydrophilic tetrasulfonated bis-triazine ligand in the aqueous phase is able to separate Am(III) from Eu(III) by selective Am(III) complex formation across a range of nitric acid concentrations with very high selectivities, and without the use of buffers. In contrast, disulfonated bis-triazine ligands are unable to separate Am(III) from Eu(III) in this system. The greater ability of the tetrasulfonated ligands to retain Am(III) selectively in the aqueous phase than the corresponding disulfonated ligands appears to be due to the higher aqueous solubilities of the complexes of the tetrasulfonated ligands with Am(III). The selectivities for Am(III) complexation observed with hydrophilic tetrasulfonated bis-triazine ligands are in many cases far higher than those found with the polyaminocarboxylate ligands previously used as actinide-selective complexing agents, and are comparable to those found with the parent hydrophobic bis-triazine ligands. Thus we demonstrate a feasible alternative method to separate actinides from lanthanides than the widely studied approach of selective actinide extraction with hydrophobic bis-1,2,4-triazine ligands such as CyMe4-BTBP and CyMe4-BTPhen.

Synthesis and evaluation of a novel hydrophilic 6,6′-bis(1,2,4-triazin-3-yl)-2,2′-bipyridine ligand for separating actinide(III) from lanthanide(III)

We report the synthesis and evaluation of a novel hydrophilic 6,6′-bis(1,2,4-triazin-3-yl)-2,2′-bipyridine (BTBP) ligand containing carboxylate groups as a selective aqueous complexing agent for the minor actinides over lanthanides. The novel ligand is able to complex and separate Am(III) from Eu(III) in alkaline solutions selectively.

Lead(II)-induced formation and coordination of 3,4-dihydro-3-thioxo-1,2,4-triazin-5(2H)-one

Cyclization of (n)butyl glyoxylate thiosemicarbazone (HBuTSC) under reflux in the presence of Pb(OAc)(2) led to tile formation of the complex [Pb(HTz)(2)] (H(2)Tz = 3,4-dihydro-3-thioxo-1,2,4-triazin-5(2H)-one), which after recrystallization from DMSO afforded the polymer [Pb(Tz)](n), the first example of a Tz(2-) metal complex. (C) 2008 Elsevier B.V. All rights reserved.

New insights on surface-enhanced Raman scattering based on controlled aggregation and spectroscopic studies, DFT calculations and symmetry analysis for 3,6-bi-2-pyridyl-1,2,4,5-tetrazine adsorbed onto citrate-stabilized gold nanoparticles

Asystematic study on the surface-enhanced Raman scattering (SERS) for 3,6-bi-2-pyridyl-1,2,4,5-tetrazine (bptz) adsorbed onto citrate-modified gold nanoparticles (cit-AuNps) was carried out based on electronic and vibrational spectroscopy and density functional methods. The citrate/bptz exchange was carefully controlled by the stepwise addition of bptz to the cit-AuNps, inducing flocculation and leading to the rise of a characteristic plasmon coupling band in the visible region. Such stepwise procedure led to a uniform decrease of the citrate SERS signals and to the rise of characteristic peaks of bptz, consistent with surface binding via the N heterocyclic atoms. In contrast, single addition of a large amount of bptz promoted complete aggregation of the nanoparticles, leading to a strong enhancement of the SERS signals. In this case, from the distinct Raman profiles involved, the formation of a new SERS environment became apparent, conjugating the influence of the local hot spots and charge-transfer (CT) effects. The most strongly enhanced vibrations belong to a(1) and b(2) representations, and were interpreted in terms of the electromagnetic and the CT mechanisms: the latter involving significant contribution of vibronic coupling in the system. Copyright (C) 2010 John Wiley & Sons, Ltd.

Ultrasound promoted greener synthesis of 2-(3,5-diaryl-4,5-dihydro-1H-pyrazol-1-yl)-4-phenylthiazoles

A rapid and cleaner procedure for the synthesis of a series of 2-(3,5-diaryl-45-dihydro-1H-pyrazol-1-yl)-4-phenylthiazoles under ultrasonic irradiation in ethanol is described. (C) 2010 Elsevier B.V. All rights reserved.

Perspective: LaGuardia Community College Newsletter Vol. 1, No. 4

"A newsletter published periodically to keep the faculty, students, staff, and community informed about the activities taking place on the campus of LaGuardia Community College." No date [1973]; Vol. 1, No. 4; 3 pages; Color (green, black & white); black & white photographs. Cover article: “Another LaGuardia First, Distinguished Professor John A. Willliams.” Other entries include: “DEAN HAMILTON WELCOMES NEW FRESHMEN.”

July 2012: Volume 1 Issue 4

In this Issue: Progress at the LibraryDacus Library of Winthrop UniversityProgress of Construction, Main Floor, Dacus Library

Currículo para formação de professores de 1. a 4. séries do 1. grau: proposta metodológica

A formação de professores para as quatro primeiras séries do 1o Grau, realizada em cursos a nível de 2o grau, apresenta graves distorções, não atingindo os objetivos propostos pela política educacional do País. Os princípios da ciência contemporânea podem e devem ser mobilizados para a solução desse problema. O estudo das estruturas cognitivas de senvolvido por Jean Piaget e seus colaboradores nos mostra que elas são conquistadas num processo operatório de açao sobre os objetos, sendo as operações formais somente possíveis de serem conquistadas a partir da adolescência, após o domínio das operações concretas. Paralelamente, a clientela das escolas estaduais vem apresentando graves limitações no desenvolvimento da linguagem falada e escrita, o que reverte progressivamente em novas dificuldades à medida que os alunos não conseguem decodificar a linguagem do professor. Procurando minorar tais dificuldades propõe-se a reformulação do currículo de For mação de Professores da la. a 4a. séries do 1o grau para as escolas de 2o grau da rede oficial do Estado do Rio de Janeiro . A metodologia que fundamenta a nova proposta curricular é desenvolvida experimentalmente numa das escolas da rede, no município do Rio de Janeiro. Analisam-se as relações teoria-prática a partir dos resultados do primeiro ano do experimento.

A concepção de professores do ensino fundamental (1ª e 4ª) sobre a saúde do escolar

Com a criação dos Parâmetros Curriculares Nacional (PCNs), a saúde passou a ser um tema transversal que deve ser trabalhado por todos os níveis de ensino em toda a escola, principalmente pelos professores do ensino fundamental, os quais têm uma grande responsabilidade no processo de formação dos valores e de condutas dos escolares. Com o objetivo de investigar a concepção dos professores de ensino fundamental (1ª a 4ª séries) sobre a saúde do escolar, este estudo teve como amostra 45 professoras lotadas em 04 escolas públicas e 04 escolas privadas no município de Natal/RN. Para a coleta dos dados foi utilizado um questionário semi-estruturado, sendo os mesmos analisados por meio da análise temática. A faixa etária com maior prevalência foi a superior a 40 anos, com 58% de professoras. Com relação ao grau de formação acadêmica das docentes investigadas, 47% delas tem o terceiro grau completo e, 40% possuem apenas formação no magistério. No que se refere ao tema transversal saúde, 27% das professoras não realizaram estudos sobre o mesmo e, 40% das docentes não se sentiam preparadas para desenvolver esse conteúdo, apontando como principal fator limitante à falta de conhecimento mais profundo sobre saúde e a falta de material didático adequado. Sobre a importância em se trabalhar a saúde, 29% das respostas referiram-se aos cuidados com a saúde, e 20% em prevenir e conhecer doenças. Pode-se concluir que é necessária uma capacitação específica referente à temática em questão, o que deve ser acompanhada de políticas públicas que incentivem o profissional da educação e ofereça estrutura ao ambiente escolar

Immunomodulatory Effects of Palladium(II) Complexes of 1,2,4-Triazole on Murine Peritoneal Macrophages

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação imuno-histoquímica das galectinas-1, -3, -4 e -7 em carcinoma epidermóide de língua.

Several studies are carried out with aim to establish parameters to determine biologic behavior of oral squamous cell carcinoma, in order this neoplasm presents high rates of morbidity and mortality. The purpose of present research was to performe a clinic, morphologic and immunohistochemical analysis by the expression of galectins 1, 3, 4 and 7 in 65 cases of tongue squamous cell carcinoma, correlating this expression with clinics (outcome of the disease, metastasis and clinical staging) and morphologic parameters (malignancy histologic gradation system). The clinical and morphologic parameters analysed and expression of galectins 1, 3, 4 and 7 were submitted to statistical analysis (Qui2 test), observing that can be utilized as indicators of the biological behavior of the tongue squamous cell carcinoma. The galectin 1 was expressed in 87,7% of cases studied and it exhibit statistically significant correlation with metastasis (p=0,033) and clinical staging (p=0,016), it is located mostly in the citoplasm of the stomal cells. The immunoexpression of galectin 3 in 87,7% of cases was correlated with the presence of metastasis (p=0,033) and malignancy histological gradation system (p=0,031), observed, mostly of cases, in tongue squamous cell carcinoma of malignancy high grading. The galectin 4 showed no statistical significance to any of the parameters evaluated. The expression of galectin 7 in 73,8% of cases showed statistically significant correlation with the malignancy histologic grading (p=0,005), which is marking exclusively found in neoplastic epithelial cells, in the mostly of cases, it is found in cytoplasm and membrane (50%). The expressive immunopositivy of the galectins 1, 3 and 7, observed in this research, leads us to suggest a broad participation of these proteins in oral carcinogenesis, and its possible use as markers of biological behavior and tumor progression in cases of squamous cell carcinoma of the tongue

A simplified and higher dynamic range version of the J(1) ... J(4) method for optical phase measurements

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Study of copper complexes adsorbed on a silica gel surface chemically modified with 2-amino-1,3,4-thiadiazole

The isotherms of adsorption of CuX2 (X=Cl-, Br-, ClO4-) by silica gel chemically modified with 2-amino-1,3,4-thiadiazole were studied in acetone and ethanol solutions: at 298 K. The following equilibria constants (in 1 mol(-1)) were determined: (a) CuCl2: 3.5 x 10(3) (ac), 2.0 x 10(3) (eth); (b) CuBr2: 2.8 x 10(3) (ac), 2.0 x 10(3) (eth); (c) Cu(ClO4)(2): 1.8 x 10(3) (ac), 1.0 x 10(3) (eth); ac = acetone, eth = ethanol. The electron spin resonance spectra of the surface complexes indicated a tetragonal distorted structure in the case of lower degrees of metal loading on the chemically modified surface. The d-d electronic transition spectra showed that for the ClO4-, complex, the peak of absorption did not change for any degree of metal loading, and for Cl- and Br- complexes, the peak maxima shifted to a higher energy region with a lower metal loading. (C) 1998 Elsevier B.V. B.V. All rights reserved.

Stripping voltammetry of mercury(II) with a chemically modified carbon paste electrode containing silica gel functionalized with 2,5-dimercapto-1,3,4-thiadiazole

The accumulation voltammetry of mercury(II) was investigated at a carbon paste electrode chemically modified with silica gel functionalized with 2,5-dimercapto-1,3,4-thiadiazole (DTTPSG-CPE). The repetitive cyclic voltammogram of mercury(II) solution in the potential range -0.2 to +0.8 V (vs. Ag/AgCl), (0.02 mol L-1 KNO3; nu=20 mV s(-1)) show two peaks one at about 0.0 V and other at 0.31 V. However, the cathodic wave peak, around 0.0 V, is irregular and changes its form in each cycle. This peak at about 0.0 V is the reduction current for mercury(II) accumulated in the DTTPSG-CPE. The anodic wave peak at 0.31 V is well-defined and does not change during the cycles. The resultant material was characterized by cyclic and differential pulse anodic stripping voltammetry performed with the electrode in differents supporting electrolytes. The mercury response was evaluated with respect to pH, electrode composition, preconcentration time, mercury concentration, cleaning solution, possible interferences and other variables. The precision for six determinations (n=6) of 0.05 and 0.20 mg (L)-(1) Hg(II) was 2.8 and 2.2% (relative standard deviation), respectively. The method was satisfactory and used to determine the concentration of mercury(II) in natural waters contaminated by this metal.