An electroanalytical application of 2-aminothiazole-modified silica gel after adsorption and separation of Hg(II) from heavy metals in aqueous solution

2-Aminothiazole covalently attached to a silica gel surface was prepared in order to obtain an adsorbent for Hg(II) ions having the following characteristics: good sorption capacity, chemical stability under conditions of use, and, especially, high selectivity. The accumulation voltammetry of mercury(II) was investigated at a carbon paste electrode chemically modified with silica gel functionalized with 2-aminothiazole (SIAMT-CPE). The repetitive cyclic voltammogram of mercury(II) solution in the potential range -0.2 to + 0.6 V versus Ag/AgCl (0.02 mol L-1 KNO3; V = 20 mV s(-1)) show two peaks one at about 0.1 V and other at 0.205 V. The anodic wave peak at 0.205 V is well defined and does not change during the cycles and it was therefore further investigated for analytical purposes using differential pulse anodic stripping voltammetry 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 0.02 and 0.20 mg L-1 Hg(II) was 4.1 and 3.5% (relative standard deviation), respectively. The detection limit was estimated as 0.10 mu g L-1 mercury(II) by means of 3:1 current-to-noise ratio in connection with the optimization of the various parameters involved and using the highest-possible analyser sensitivity. (c) 2006 Elsevier Ltd. All rights reserved.

Efeito da interação genótipo × ambiente sobre o peso ao nascimento, aos 205 e aos 550 dias de idade de bovinos da raça Nelore na Região Sul do Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for scalar leptoquarks and T-odd quarks in the acoplanar jet topology using 2.5 fb(-1) of p(p)over-bar collision data at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização estrutural da cerâmica Ti x(Sm0,2Ce0,8)1-xO 2-delta pelo método de Rietveld

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

Synthesis, characterization and thermal studies on solid compounds of 2-chlorobenzylidenepyruvate of heavier trivalent lanthanides and yttrium(III)

Solid-state compounds of general formula LnL(3)center dot nH(2)O, where Ln represents heavier lanthanides and yttrium and L is 2-chlorobenzylidenepyruvate, have been synthesized. Chemical analysis, simultaneous thermogravimetry-differential analysis (TG-DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, elemental analysis and infrared spectroscopy have been employed to characterize and to study the thermal behaviour of these compounds in dynamic air atmosphere.On heating these compounds decompose in four (Gd, Tb, Ho to Lu, Y) or five (Eu, Dy) steps. They lose the hydration water in the first step and the thermal decomposition of the anhydrous compounds up to 1200 degrees C occurs with the formation of the respective oxide, Tb4O7 and Ln(2)O(3) (Ln=Eu, Gd, Dy to Lu and Y) as final residue. The dehydration enthalpies found for these compounds (Eu, to Lu and Y) were: 65.77, 55.63, 86.89, 121.65, 99.80, 109.59, 131.02, 119.78, 205.46 and 83.11 kJ mol(-1), respectively.

Interface formation of nanostructured heterojunction SnO 2:Eu/GaAs and electronic transport properties

Thin films of tin dioxide (SnO2) are deposited by the sol-gel-dip-coating technique, along with GaAs layers, deposited by the resistive evaporation technique. The as-built heterojunction has potential application in optoelectronic devices, combining the emission from the rare-earth doped transparent oxide (Eu3+-doped SnO2 presents very efficient red emission) with a high mobility semiconductor. The advantage of this structure is the possibility of separation of the rare-earth emission centers from the electron scattering, leading to a strongly indicated combination for electroluminescence. Electrical characterization of the heterojunction SnO2:Eu/GaAs shows a significant conductivity increase when compared to the conductivity of the individual films, and the monochromatic light irradiation (266 nm) at low temperature of the heterojunction GaAs/SnO2:Eu leads to intense conductivity increase. Scanning electron microscopy (SEM) of the heterojunction cross section shows high adherence and good morphological quality of the interfaces substrate/SnO2 and SnO2/GaAs, even though the atomic force microscopy (AFM) image of the GaAs surface shows disordered particles, which increases with sample thickness. On the other hand, the good morphology of the SnO2:Eu surface, shown by AFM, assures the good electrical performance of the heterojunction. The observed improvement on the electrical transport properties is probably related to the formation of short conduction channels at the semiconductors interface, which may exhibit two-dimensional electron gas (2DEG) behavior. © 2012 Elsevier B.V. All rights reserved.

A implantação da reforma do ensino de 1º e 2º graus no estado de São Paulo nas páginas da imprensa (1971-1982)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Síntese, caracterização e estudo do comportamento térmico dos 2-clorobenzalpiruvatos de lantânio (III), lantanídios (III) e de ítrio (III), no estado sólido

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Magnetocrystalline interactions and oxidation state determination of Mn(2-x)V(1+x)O4 (x=0, 1/3 and 1) magnetorresistive spinel family

Oxidation states of transition metal cations in spinels-type oxides are sometimes extremely difficult to determine by conventional spectroscopic methods. One of the most complex cases occurs when there are different cations, each one with several possible oxidation states, as in the case of the magnetoresistant Mn(2-x)V(1+x)O4 (x=0, 1/3 and 1) spinel-type family. In this contribution we describe the determination of the oxidation state of manganese and vanadium in Mn(2-x)V(1+x)O4 (x=0, 1/3,1) spinel-type compounds by analyzing XANES and high-resolution K beta X-ray fluorescence spectra. The ionic models found are Mn22+V4+O4, Mn5/32+V4/33.5+O4 and Mn2+V23+O4. Combination of the present results with previous data provided a reliable cation distribution model. For these spinels, single magnetic electron paramagnetic resonance (EPR) lines are observed at 480 K showing the interaction among the different magnetic ions. The analysis of the EPR parameters show that g-values and relative intensities are highly influenced by the concentration and the high-spin state of Mn2+. EPR broadening linewidth is explained in terms of the bottleneck effect, which is due to the presence of the fast relaxing V3+ ion instead of the weak Mn2+ (S state) coupled to the lattice. The EPR results, at high temperature, are well explained assuming the oxidation states of the magnetic ions obtained by the other spectroscopic techniques. (c) 2013 Elsevier Inc. All rights reserved.

Efficacy and safety of ovarian stimulation before chemotherapy in 205 cases

Ovarian stimulation and cryopreservation of fertilized oocytes before cancer therapy is the best established and efficient fertility preservation technique and should still be considered before chemotherapy. Within a short time frame of 2 weeks, between 8.6 (18-25 y) and 5.1 (36-40 y) fertilized oocytes can be cryopreserved.

Immunopathology of postprimary tuberculosis: increased T-regulatory cells and DEC-205-positive foamy macrophages in cavitary lesions.

Postprimary tuberculosis occurs in immunocompetent people infected with Mycobacterium tuberculosis. It is restricted to the lung and accounts for 80% of cases and nearly 100% of transmission. Little is known about the immunopathology of postprimary tuberculosis due to limited availability of specimens. Tissues from 30 autopsy cases of pulmonary tuberculosis were located. Sections of characteristic lesions of caseating granulomas, lipid pneumonia, and cavitary stages of postprimary disease were selected for immunohistochemical studies of macrophages, lymphocytes, endothelial cells, and mycobacterial antigens. A higher percentage of cells in lipid pneumonia (36.1%) and cavitary lesions (27.8%) were positive for the dendritic cell marker DEC-205, compared to granulomas (9.0%, P < .05). Cavities contained significantly more T-regulatory cells (14.8%) than found in lipid pneumonia (5.2%) or granulomas (4.8%). Distribution of the immune cell types may contribute to the inability of the immune system to eradicate tuberculosis.

Na 1 Nachlass Max Horkheimer, 1 - Korrespondenzen u.a. mit Franz Alexander (p. I 1, 1-205)

1 Brief von Max Horkheimer an Abel, 16.03.1936; 3 Briefe zwischen Hubert Abrahamsohn und Max Horkheimer, 1935-1936, 21.12.1936; 2 Briefe zwischen Emanuel Adler und Max Horkheimer, 12.04.1946, 26.04.1946; 2 Briefe zwischen Max Adler und Max Horkheimer, 16.03.1935, 29.03.1935; 1 Brief von Eva Ahamson an Max Horkheimer, 01.11.1944; 2 Briefe der Aircraft Warning Service Brentwood an Max Horkheimer, Mai 1942; 6 Briefe zwischen Librairie Félix Alcan und Max Horkheimer, 1935, 18.12.1935; 11 Briefe zwischen Franz Alexander und Max Horkheimer, 1938-1940; 2 Briefe zwischen der American Historical Review New York und Max Horkheimer, 01.04.1941, 07.04.1941; 1 Brief von Paul Reiwald an Max Horkheimer, 18.10.1940; 2 Briefe zwischen Helen Manice Alexander und Max Horkheimer, 1936; 2 Briefe zwischen Bernardine Allen und Max Horkheimer, 17.06.1938, 24.06.1938; 1 Brief der Alumni Federation of Columbia University an Max Horkheimer, 21.07.1942; 1 Brief der American Friends Service Comittee an Max Horkheimer, 10.12.1940; 3 Briefe zwischen der American Academy of Political and Social Science Philadelphia und Max Horkheimer, 1939,1940, 16.01.1939; 1 Brief der American Automobile Association Washington an Max Horkheimer, 22.03.1938; 1 Brief der American Association for the Advancement of Science Washington an Max Horkheimer, 16.08.1937; 2 Briefe von Max Horkheimer an den American Consulate General Berlin, 1939; 1 Brief von Max Horkheimer an den American Consulate General Havana, 03.03.1941; 4 Briefe von Max Horkheimer an den American Consul London, 1939-1941; 2 Briefe von Max Horkheimer an den American Consulate General Stuttgart, 1939-1941; 1 Brief von Max Horkheimer an den American Consul Zürich, 1939; 1 Brief von Friedrich Pollock an den American Council of Learned Society, Washington, 27.06.1941; 2 Briefe von Max Horkheimer an die American Friends of German Freedom New York, 1941; 4 Briefe der American Historical Association Washington an Max Horkheimer, 1937-1938; 1 Brief von Max Horkheimer an den American Red Cross Westwood Office, 21.06.1943; 18 Briefe zwschen der American Society for the Prevention of Cruelty to Animals New York und Max Horkheimer, 1936-1941; 1 Brief von Max Horkheimer an die American Women's Volunteer Service Pacific Palisades, 27.07.1942; 23 Briefe zwischen Eugene Anderson und Max Horkheimer, 1937-1941; 2 Briefe zwischen Norah Andreae und Max Horkheimer, 27.10.1944, 09.09.1946; 1 Brief von Rosa Nebel-Schenk, 04.03.1946; 1 Brief von der National Catholic Welfare Conference, 14.08.1944; 12 Briefe zwischen Werner Andreae und Max Horkheimer, 1945-1954; 1 Brief von Julius Marx an Werner Andreae, 10.05.1946, 11.05.1950; 2 Briefe von Josef Messinger an Werner Andreae, 23.10.1946, ohne Datum; 3 Briefe zwischen dem Advokatenbüro Hodler und Max Horkheimer, 1946, 09.05.1946;