Synthesis and solid-state structural characterization of bis (thiocyanatemercury)tetracarbonyliron

The bis (thiocyanatemercury)tetracarbonyliron, [Fe(CO)4(HgSCN)2], was prepared from [Fe(CO) 5] and Hg(SCN)2, and studied by IR spectroscopy and X-ray diffraction. The compound crystallizes in the tetragonal space group I4,1/a. The unit cell, with dimensions of a = 13.778(3), c = 13.234(3) Å, V = 2512.3(9) Å3, contains four molecules. The iron atom is octahedrally coordinated by four carbonyl groups and two mercury atoms in cis positions. The coordination of the mercury atoms is distorted square-planar, since, besides mercury-iron and mercury-sulphur bonds, there are also mercury-mercury and mercury-nitrogen interactions. The FeHg distance is 2.506(5)Å and the HgFeHg angle is 78.0(1)°. © 1987.

Effects of fibrin adhesive material (Tissucol) on alveolar healing in rats under stress.

The effects of Tissucol on alveolar healing following stress were evaluated histologically, comparing three groups of 28 male albino rats each. Stress was applied and their right upper incisors were extracted. Group A served as an empty control site. In Group B, Tissucol was applied into the alveolar cavity. Group C received local antifibrinolytic treatment (alveolar irrigation with epsilon-aminocaproic acid solution) before implant of Tissucol into the tooth socket. Four animals in each group were killed at 1, 3, 6, 9, 15, 21 and 24 days after surgery. Results showed that: 1) Tissucol did not interfere with connective and osseous tissue formation; 2) Tissucol allowed new bone formation; 3) Tissucol residues in Group B in sections of 24-day specimens did not impair healing; 4) Tissucol was usually completely resorbed and healing was complete 24 days after surgery in Group C.

Crystal structures and magnetic properties of CuX2(pdmp)2 complexes (X = Br, Cl)

We report the synthesis and the structural and magnetic characterization of two new compounds: dibromobis-(pdmp)copper(II), CuBr2C22H24N4 (1), and dichlorobis(pdmp)copper(II), CuCl2C22H24N4 (2), where pdmp = 1-phenyl-3,5-dimethylpyrazole. The structures were refined by full-matrix least-squares techniques to R1 = 0.0620 and 0.0777, respectively. Compound 1 belongs to the space group P21/n with a = 8.165(5) Å, b = 10.432(3) Å, c = 13.385(4) Å, β = 100.12(4)̊, and Z = 2. Compound 2 belongs to the space group P21/c with a = 8.379(2) Å, b = 22.630(2) Å, c = 12.256(2) Å, β= 98.43(3)°, and Z = 4. It has the same molecular formula as a compound reported previously but a different crystal structure. Detailed single-crystal EPR measurements were performed for single-crystal samples of 1 and 2 at 9 and 35 GHz and at room temperature. The positions and line widths of the EPR lines were measured as a function of the magnetic field orientation in three orthogonal planes. The data were used to study the electronic properties of the copper ions and to evaluate the exchange interactions between them. Our results are discussed in terms of the electronic pathways for superexchange between copper ions, which are provided by the stacking of pyrazole and phenyl rings of neighboring molecules and by hydrogen-halogen bonds. © 1999 American Chemical Society.

Comparison of the shear bond strengths of conventional mesh bases and sandblasted orthodontic bracket bases

This study aimed to compare in vitro the shear bond strength between metallic brackets (Abzil) with conventional mesh bases and metallic brackets with bases industrially sandblasted with aluminum oxide using three adhesive systems, in order to assess the influence of sandblasting on adhesiveness and to compare 3 different bonding systems. Two hundred and forty bovine incisors were used and randomly divided into 6 groups (40 teeth in each group), according to the bracket base and to the bonding system. The brackets were direct-bonded in bovine teeth with 3 adhesive systems: System A - conventional Transbond™ XT (3M -Unitek); System B - Transbond™ Plus Self Etching Primer + Transbond™ XT (3M - Unitek) and System C - Fuji ORTHO LC resin-reinforced glass ionomer cement in capsules (GC Corp.). Shear bond strength tests were performed 24 hours after bonding, in a DL-3000 universal testing machine (EMIC), using a load cell of 200 kgf and a speed of 1 mm/min. The results were submitted to statistical analysis and showed no significant difference between conventional and sandblasted bracket bases. However, comparison between the bonding systems presented significantly different results. System A (14.92 MPa) and system C (13.24 MPa) presented statistically greater shear bond strength when compared to system B (10.66 MPa). There was no statistically significant difference between system A and system C.

Caracterização de alterações radiográficas na articulação metacarpofalângia de cavalos de três tambores

Pós-graduação em Medicina Veterinária - FMVZ

Estudo teórico - experimental do titanato de cálcio - 'CA''TI''OIND.3'

Pós-graduação em Química - IQ

Comparação da resistência ao cisalhamento de bráquetes com e sem tratamento na base utilizando três sistemas de colagem

Pós-graduação em Odontologia - FOA

Cicatrização óssea de defeitos de tamanho crítico tratados com Aspirado de Medula Óssea, Laser em Baixa Intensidade ou a associação de ambas as terapias: estudo histológico e histométrico em calvárias de ratos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização dos dejetos de novilhos superprecoces: reciclagem energética e de nutrientes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação do reparo ósseo de defeitos de tamanho crítico tratados com plasma rico em plaquetas ou com fibrina rica em plaquetas: estudo histomorfométrico e imunoistoquímico em calvárias de ratos

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

Effect of Sodium Ascorbate on Dentin Bonding After Two Bleaching Techniques

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

The use of stable isotopes to investigate the effects of supplemental lysine and methionine on protein turnover and amino acid utilization in pacu, Piaractus mesopotamicus, juveniles

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of litter manipulation in a tropical Eucalyptus plantation on leaching of mineral nutrients, dissolved organic nitrogen and dissolved organic carbon

Although many studies have shown that soil solution chemistry can be a reliable indicator of biogeochemical cycling in forest ecosystems, the effects of litter manipulations on the fluxes of dissolved elements in gravitational soil solutions have rarely been investigated. We estimated the fluxes of NH4-N, NO3-N, K, Ca, Mg, Na, Cl, dissolved organic nitrogen (DON) and dissolved organic carbon (DOC) over the first two years after re-planting Eucalyptus trees in the coastal area of Congo. Two treatments were replicated in two blocks after clear-cutting 7-year-old stands: in treatment R, all the litter above the mineral soil was removed before planting, and in a double slash (DS) treatment, the amount of harvest residues was doubled. The soil solutions were sampled down to a depth of 4 m and the water fluxes were estimated using the Hydrus 1D model parameterized from soil moisture measurements in 4 plots. Isotopic and spectroscopic analytical techniques were used to assess the changes in dissolved organic matter (DOM) properties throughout the transfer in the soil. The first year after planting, the fluxes of NH4-N, K, Ca, Mg, Na, Cl and DOC in the topsoil of the DS treatment were 2-5 times higher than in R, which showed that litter was a major source of dissolved nutrients. Nutrient fluxes in gravitational solutions decreased sharply in the second year after planting, irrespective of the soil depth, as a result of intense nutrient uptake by Eucalyptus trees. Losses of dissolved nutrients were noticeably low in these Eucalyptus plantations despite a low cation exchange capacity, a coarse soil texture and large amounts of harvest residues left on-site at the clear cut in the DS treatment. All together, these results clarified the strong effect of litter manipulation observed on eucalypt growth in Congolese sandy soils. DOM fluxes, as well as changes in delta C-13, C:N and aromaticity of DOM throughout the soil profile showed that the organic compounds produced in the litter layer were mainly consumed by microorganisms or retained in the topsoil. Below a depth of 15 cm, most of the DOC and the DON originated from the first 2 cm of the soil and the exchanges between soil solutions and soil organic matter were low. (C) 2014 Elsevier B.V. All rights reserved.

Comparison of Nonmesonic Hypernuclear Decay Rates Computed in Laboratory and Center-of-Mass Coordinates

In this work we compute the one-nucleon-induced nonmesonic hypernuclear decay rates of He-5(Lambda), C-12(Lambda) and C-13(Lambda) using a formalism based on the independent particle shell model in terms of laboratory coordinates. To ascertain the correctness and precision of the method, these results are compared with those obtained using a formalism in terms of center-of-mass coordinates, which has been previously reported in the literature. The formalism in terms of laboratory coordinates will be useful in the shell-model approach to two-nucleon-induced transitions.

Organic farm does not improve neither soil, or water quality in rural watersheds from southeastern Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)