Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Clin Anat ; 31(5): 734-741, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28960445

RESUMO

Cutaneous nerves have branches called vascular branches (VBs) that reach arteries. VBs are thought to be involved in arterial constriction, and this is the rationale for periarterial sympathectomy as a treatment option for Raynaud's disease. However, the branching patterns and distribution areas of the VBs remain largely unclear. The aim of the present study was to investigate the anatomical structures of the VBs of the cutaneous nerves. Forty hands and forearms were examined to assess the branching patterns and distribution areas of the VBs of the superficial branch of the radial nerve (SBRN), the lateral antebrachial cutaneous nerve (LACN), the medial antebrachial cutaneous nerve (MACN), and the palmar cutaneous branch of the ulnar nerve (PCUN). VBs reaching the radial and ulnar arteries were observed in all specimens. The branching patterns were classified into six types. The mean distance between the radial styloid process and the point where the VBs reached the radial artery was 34.3 ± 4.8 mm in the SBRN and 38.5 ± 15.8 mm in the LACN. The mean distance between the ulnar styloid process and the point where the VBs reached the ulnar artery was 60.3 ± 25.9 mm in the MACN and 43.8 ± 26.0 mm in the PCUN. This study showed that the VBs of the cutaneous nerves have diverse branching patterns. The VBs of the SBRN had a more limited distribution areas than those of the other nerves. Clin. Anat. 31:734-741, 2018. © 2017 Wiley Periodicals, Inc.


Assuntos
Antebraço/irrigação sanguínea , Mãos/irrigação sanguínea , Artéria Radial/inervação , Artéria Ulnar/inervação , Idoso , Idoso de 80 Anos ou mais , Feminino , Antebraço/inervação , Mãos/inervação , Humanos , Masculino , Doença de Raynaud/cirurgia
2.
Folia Morphol (Warsz) ; 81(2): 493-502, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33634835

RESUMO

BACKGROUND: The incidence of an elongated styloid process (SP) and average length and diameter of SP have not been reported using Japanese cadavers. Data on the female-to-male ratio of an elongated SP vary. We calculated the average length and diameter of SP in Japanese cadavers and compared SP lengths between sexes. MATERIALS AND METHODS: Twenty-seven sides (right and left of bodies) in males and 51 sides in females were analysed. Measurements were obtained from the inferior external acoustic meatus to the distal tip of the SP. SP diameters at the proximal base, midpoint, and distal tip were measured. SP > 30 mm was considered elongated. We used Welch's t-test for the statistical analysis. Fisher's exact two-tailed test was also performed to analyse the female-to-male elongation ratio. A p-value < 0.05 was considered statistically significant. RESULTS: Styloid process elongation prevalence was 29.5% in our sample. The average full length was 27.04 ± 7.88 mm overall; the average diameters were 5.41 ± 1.77 mm at the proximal base and 2.21 ± 1.22 mm at the distal tip. The average SP measurement was 26.81 ± 5.92 mm in males and 27.16 ± 8.79 mm in females (p = 0.74). The female-to-male ratio of SP elongation was 1:2 (p = 0.041). Females had longer full lengths of non-elongated SPs than males (p = 0.004). Males had wider diameters at the proximal base of elongated SPs than females (p = 0.017). CONCLUSIONS: The average length of SP was 27.04 mm in the Japanese population and about 30% of the Japanese presented SP ≥ 30 mm. Male had significantly higher rate than female among the SP ≥ 30 mm, and female had significantly longer SPs than male among the SP < 30 mm. Anatomically, the SP gets narrow as distally goes. Our anatomical findings would be beneficial to creating treatment plans, diagnosis, and surgery.


Assuntos
Ossificação Heterotópica , Osso Temporal , Cadáver , Feminino , Humanos , Japão , Masculino , Osso Temporal/anormalidades , Osso Temporal/anatomia & histologia
3.
Folia Morphol (Warsz) ; 80(2): 324-330, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32488854

RESUMO

BACKGROUND: A gonadal artery originates as a branch of the abdominal aorta and renal artery inferior to the level of origin of the renal arteries. Variations in multiple right testicular arteries (RTAs) arising from the abdominal aorta are common. We aimed to re-evaluate the unusual courses of gonadal arteries with a single common trunk in relation to the inferior vena cava and left renal vein and explain the developmental anatomy. MATERIALS AND METHODS: The observational cross-sectional study was performed on 54 Japanese adult cadavers (29 men and 25 women). We examined the literature and developed embryological hypotheses on the single common trunk of the gonadal artery. RESULTS: The gonadal artery, testicular artery, and ovarian artery arose from the abdominal aorta in 93.1%, 96.3%, and 89.6% of cases, respectively, and from the renal artery in 4.9%, 3.7%, and 6.3% of cases, respectively. We found two rare variations in the RTAs observed during the routine dissection of two male cadavers; in these two cases, a single common trunk of the RTAs originated from the abdominal aorta. A single common trunk was found in 3.7% of cadavers, 2.0% of sides, and 2.0% of arteries in the gonadal artery and in 6.9% of cadavers, 3.8% of sides, and 3.7% of arteries in the testicular artery. All cases of the single common trunk, including those in past reports, were observed only in men. CONCLUSIONS: Knowledge of the variations in RTAs has important clinical consequences for invasive and non-invasive arterial procedures. In addition, this variation provides a new interpretation of the embryology of the gonadal artery. Variations similar to our findings have not been previously reported. Therefore, different variations concerning the RTA should be considered during surgical and non-surgical evaluations.


Assuntos
Artéria Renal , Testículo , Adulto , Aorta Abdominal , Cadáver , Estudos Transversais , Feminino , Humanos , Masculino , Veias Renais
4.
J Phys Condens Matter ; 19(31): 315219, 2007 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-21694119

RESUMO

The transition metal (TM) chalcogenides of the form TMX(2) (X = S or Se) have been studied for decades due to their interesting electronic and magnetic properties such as metamagnetism and metal-insulator transitions. In particular, the Co(1-x)Fe(x)S(2) alloys were the subject of investigation in the 1970s due to general interest in itinerant ferromagnetism. In recent years (2000-present) it has been shown, both by electronic structure calculations and detailed experimental investigations, that Co(1-x)Fe(x)S(2) is a model system for the investigation of highly spin polarized ferromagnetism. The radically different electronic properties of the two endpoint compounds (CoS(2) is a narrow bandwidth ferromagnetic metal, while FeS(2) is a diamagnetic semiconductor), in a system forming a substitutional solid solution allows for composition control of the Fermi level relative to the spin split bands, and therefore composition-controlled conduction electron spin polarization. In essence, the recent work has shown that the concept of 'band engineering' can be applied to half-metallic ferromagnets and that high spin polarization can be deliberately engineered. Experiments reveal tunability in both sign and magnitude of the spin polarization at the Fermi level, with maximum values obtained to date of 85% at low temperatures. In this paper we review the properties of Co(1-x)Fe(x)S(2) alloys, with an emphasis on properties of relevance to half-metallicity. Crystal structure, electronic structure, synthesis, magnetic properties, transport properties, direct probes of the spin polarization, and measurements of the total density of states at the Fermi level are all discussed. We conclude with a discussion of the factors that influence, or even limit, the spin polarization, along with a discussion of opportunities and problems for future investigation, particularly with regard to fundamental studies of spintronic devices.

5.
Chem Commun (Camb) ; 53(82): 11298-11301, 2017 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-28920592

RESUMO

A simple and fast one-step fabrication method of silver nanoparticles (AgNPs) on a polydimethylsiloxane (PDMS) film and their improvement as highly sensitive surface enhanced Raman scattering (SERS) substrates via atomically thin Au coatings is demonstrated. The thin Au layer provides oxidation resistivity while maintaining the broad spectral range SERS sensitivity of Ag nanoparticles.

6.
Transplant Proc ; 48(4): 1288-91, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27320606

RESUMO

Cellular survival and death are at least partially regulated by the phosphorylation of proteins. A chaperon protein, 14-3-3ζ, regulates the activity of many proteins by covering the phosphorylation site within a 14-3-3 binding motif. Therefore, regulation of 14-3-3ζ activity may affect the fate of cells subjected to cold preservation and/or hypothermic oxygenated conditions. The present study assessed whether 14-3-3ζ protects cells from hypothermic oxygenation-induced injury and clarified its role in mitochondrial functions. Human renal tubular cell line HK-2 or 14-3-3ζ-overexpressed HK-2 (ζHK-2) cells were subjected to 72 hours of normoxic cold preservation in UW solution with or without antioxidants and hydroperoxides. Cellular death, adenosine triphosphate (ATP) content, and MTT catabolism were evaluated. Deferoxamine treatment reduced cellular death and augmented ATP content in both cell types. These indices were higher in ζHK-2, regardless of deferoxamine treatment. Exposure to hydroperoxides did not affect cellular death in either cell type, whereas hydroperoxide supplementation significantly reduced ATP content, except for low-dose hydrogen peroxide in HK-2 cells. MTT assay at normal state showed higher values in ζHK-2 cells, whereas it was impaired by hydroperoxides in both cell types. These results suggest that accumulation of hydroperoxides as a byproduct of the augmented oxidative phosphorylation by 14-3-3ζ overexpression causes mitochondrial dysfunction. In conclusion, despite possessing many potentially protective functions, 14-3-3ζ exacerbates cellular injury under hypothermic oxygenated conditions. 14-3-3ζ accelerates mitochondrial functions together with iron-dependent oxidative damage. Although further investigations are necessary, upregulation of 14-3-3ζ could be a method to maintain mitochondrial function under hypothermic oxygenated conditions, as shown in hypothermic machine preservation of renal grafts, when appropriate antioxidant treatment is administered.


Assuntos
Proteínas 14-3-3/fisiologia , Túbulos Renais/fisiologia , Proteínas 14-3-3/metabolismo , Adenosina/farmacologia , Alopurinol/farmacologia , Antioxidantes/farmacologia , Soluções Cardioplégicas/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Criopreservação/métodos , Desferroxamina/farmacologia , Glutationa/farmacologia , Humanos , Insulina/farmacologia , Túbulos Renais/citologia , Túbulos Renais/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/fisiologia , Preservação de Órgãos/métodos , Soluções para Preservação de Órgãos/farmacologia , Fosforilação Oxidativa , Estresse Oxidativo/fisiologia , Rafinose/farmacologia , Sideróforos/farmacologia
7.
Protein Sci ; 10(11): 2393-400, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11604544

RESUMO

The binding of a nitroxide spin-labeled analog of N-acetyllactosamine to galectin-3, a mammalian lectin of 26 kD size, is studied to map the binding sites of this small oligosaccharide on the protein surface. Perturbation of intensities of cross-peaks in the (15)N heteronuclear single quantum coherence (HSQC) spectrum of full-length galectin-3 owing to the bound spin label is used qualitatively to identify protein residues proximate to the binding site for N-acetyllactosamine. A protocol for converting intensity measurements to a more quantitative determination of distances between discrete protein amide protons and the bound spin label is then described. This protocol is discussed as part of a drug design strategy in which subsequent perturbation of chemical shifts of distance mapped amide cross-peaks can be used effectively to screen a library of compounds for other ligands that bind to the target protein at distances suitable for chemical linkage to the primary ligand. This approach is novel in that it bypasses the need for structure determination and resonance assignment of the target protein.


Assuntos
Oligossacarídeos/química , Proteínas/química , Amino Açúcares/química , Antígenos de Diferenciação/química , Sítios de Ligação , Óxidos N-Cíclicos , Desenho de Fármacos , Galectina 3 , Ligantes , Espectroscopia de Ressonância Magnética/métodos , Mapeamento de Interação de Proteínas , Marcadores de Spin
8.
FEBS Lett ; 418(1-2): 76-82, 1997 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-9414099

RESUMO

Investigation of the width of the minor groove using 500 MHz NMR spectroscopy in three closely related 11-mer B-DNA duplexes shows that the minor groove is narrow in a GC rich oligonucleotide, and that a narrow minor groove is not something endemic to DNAs with persistent repetitions of adenine nucleotides (A-tract DNA). The width of the groove is dictated by local sequence contexts and independent of neighboring A-tract DNA.


Assuntos
DNA/química , Conformação de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Composição de Bases , Sequência de Bases , Citosina , Guanina , Ressonância Magnética Nuclear Biomolecular
9.
J Biochem ; 111(2): 249-58, 1992 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1569049

RESUMO

We analyzed the structure and the expression of Kunitz chymotrypsin inhibitor (WCI) genes in winged bean. WCI was encoded by a multigene family which comprised at least seven members. From their primary structures, four genes (WCI-2, WCI-3a, WCI-3b, and WCI-x) were expected to be functional ones and the other three (WCI-P1, WCI-P2, and WCI-P3) to be pseudogenes. The nucleotide sequences of the WCI-3a and WCI-3b genes were nearly identical, and they encoded the WCI-3 protein, the major chymotrypsin inhibitor in seeds. The WCI-2 gene also encoded the chymotrypsin inhibitor found in seeds and the WCI-x gene was expected to encode an unidentified chymotrypsin inhibitor. WCI messenger RNA and protein accumulated mainly in developing seeds and tuberous roots, small amounts of WCI mRNA being present in stems and pericarps. In seeds, transient accumulation of WCI mRNA was observed during the seed maturation period. These results suggest that the expression of WCI genes is regulated organ-specifically and developmentally in winged bean.


Assuntos
Quimotripsina/antagonistas & inibidores , Proteínas de Plantas/genética , Sequência de Aminoácidos , Sequência de Bases , Fabaceae/química , Dados de Sequência Molecular , Proteínas de Plantas/química , Plantas Medicinais
10.
J Dent Res ; 81(7): 482-6, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12161461

RESUMO

The hydrolytic stability of a group of experimental composite materials was evaluated. Seven distinct composites were formed by the mixing of a resin monomer mixture with silica filler that had been pre-treated with one of 7 different ethanol solutions. In one case, the filler was treated with an ethanol solution that contained only 3-methacryloyloxypropyltrimethoxysilane. In 5 cases, it was treated with solution containing a mixture of 3-methacryloyloxypropyltrimethoxysilane and one of the following hydrophobic fluoroalkyltrimethoxysilanes: trifluoropropyl-, nonafluorohexyl-, tridecafluorooctyl-, heptadecafluorodecyl-, and henicosafluorododecyl-trimethoxysilane. The tensile strength, after being immersed in water for 1800 days, of 2 of the experimental composites, whose pre-treatment regimen had included a fluoroalkyltrimethoxysilane, was significantly higher than that of the composite whose pre-treatment regimen had not included a fluoroalkyltrimethoxysilane. Moreover, there was no significant difference between the tensile strength of fresh samples of these 2 composites and the tensile strength of identically produced samples that had remained under water for 1800 days or that had been subjected to 30,000 cycles of thermal stress.


Assuntos
Resinas Compostas/química , Materiais Dentários/química , Silanos/química , Absorção , Alcanos/química , Análise de Variância , Etanol/química , Humanos , Hidrólise , Interações Hidrofóbicas e Hidrofílicas , Imersão , Teste de Materiais , Metacrilatos/química , Dióxido de Silício/química , Óleos de Silicone/química , Solventes/química , Estatística como Assunto , Propriedades de Superfície , Resistência à Tração , Termodinâmica , Fatores de Tempo , Água/química , Molhabilidade
11.
J Biomol Struct Dyn ; 6(3): 593-608, 1988 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3271541

RESUMO

The detailed binding mechanism of wheat germ agglutinin (WGA) with N-acetylglucosamine (GlcNAc) was investigated using intermolecular 1H-1H nuclear Overhauser effect (NOE) and atomic pair potential (APP) calculations. Negative NOE was observed on the 1H spectrum of 1-O-methyl derivative of GlcNAc in a solution containing WGA, when the aromatic region of the WGA spectrum was irradiated. Analyses of the time dependence of NOE revealed that H2 and the N-acetyl methyl protons of the sugar are in close proximity to the aromatic protons of WGA in the bound state. This was confirmed and further elucidated by the APP calculations. According to the calculation, the major binding force comes from a hydrogen-bonding between C3-OH of sugar and an acidic residue present in each of the two binding sites of WGA: Glu115 in site 1 and Asp29 in site 2. The binding is further assisted by the N-acetyl group which interacts with a few more polar amino acid residues in the binding sites. The optimized binding mode suggested by the APP calculations supports the NMR results in that H2 and a part of the N-acetyl methyl protons are within 4.5 A distance from protons of both Tyr64 and Tyr73 in site 1 and of Tyr159 in site 2.


Assuntos
Acetilglucosamina , Glucosamina , Aglutininas do Germe de Trigo , Glucosamina/análogos & derivados , Espectroscopia de Ressonância Magnética/métodos , Estrutura Molecular , Conformação Proteica , Teoria Quântica
12.
J Biomol Struct Dyn ; 9(6): 1131-53, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1322143

RESUMO

The oligonucleotide d(G5T5) can in principle form a fully matched duplex with G.T pairing and/or a tetraplex. Non-denaturing gel electrophoresis, circular dichroism and NMR experiments show that the tetraplex is exclusively formed by this oligomer in solution. In the presence of its complementary strand d(A5C5) at low temperature, d(G5T5) forms the tetraplex over the normally expected Watson-Crick duplex. However, when d(G5T5) and d(A5C5) are mixed together in equimolar amounts and heated for several minutes at 85 degrees C, and then allowed to cool, the product was essentially the Watson-Crick duplex. The lack of resolution in the 500 MHz 1H NMR spectra and the presence of extensive spin diffusion do not allow us to derive a quantitative structure for the tetraplex from the NMR data. However, we find good qualitative agreement between the NOESY and MINSY data and a theoretically derived stereochemically sound structure in which the G's and T's are part of a parallel tetraplex.


Assuntos
DNA/química , Espectroscopia de Ressonância Magnética , Conformação de Ácido Nucleico , Sequência de Bases , Ligação de Hidrogênio , Dados de Sequência Molecular , Ácidos Nucleicos Heteroduplexes/química , Prótons , Soluções , Estereoisomerismo , Difração de Raios X
13.
J Biomol Struct Dyn ; 8(3): 461-82, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2100514

RESUMO

When the oligodeoxynucleotides d(A)6 and d(T)6 are mixed together in a 1:1 ratio (in 100 mM NaCl), the NH signals in the NMR spectrum gave a typical signature of Watson-Crick paired (WC) and Hoogsteen paired (H) AT base pairs. The observation indicates two schemes: Scheme I, WC and H duplexes in slow equilibrium, i.e., WC in equilibrium with H, Scheme II, the WC helix formed is unstable and that it disproportionates into a triple helix (TR) and free d(A)6. We show that (i) addition of extra d(A)6 does not change the helix composition, (ii) addition of a minor-groove specific drug Dst2 (a distamycin analogue) results in an exclusive WC helix-drug duplex, while it does not destabilize triple helix in a 1:2 mixture. In addition we have compared the melting profile, 31P NMR spectra, 1H NMR spectra and the salt dependence of the 1:1 mixture and that of a pure triple helix. All the data from the above experiments overwhelmingly favor Scheme I. However Scheme II cannot be categorically excluded. Based on 1D/2D NMR studies, we have characterized the structural properties of the Hoogsteen double helix in terms of nucleotide conformations. In addition, we computationally demonstrate that the relative stability of the WC over the H duplexes increases with increasing chain length.


Assuntos
Composição de Bases , DNA/química , Adenina/química , Distamicinas , Cloreto de Magnésio , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Conformação de Ácido Nucleico , Cloreto de Sódio , Soluções , Temperatura , Timina/química
14.
Int J Biol Macromol ; 17(3-4): 227-35, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7577822

RESUMO

Molecular dynamics (MD) simulations of methyl N,N'-diacetyl-beta-D-chitobioside (GlcNAc beta-(1-->4)GlcNAc beta-OMe) have been performed both in vacuo and in aqueous solution with the explicit inclusion of the solvent water molecules. The beta-(1-->4) glycosidic linkage fluctuates considerably, over a range of +/- 10 degrees, in each of the MD simulations in vacuo and in aqueous solution. The intra- and inter-residue hydrogen bonds in vacuo are replaced by intermolecular hydrogen bonds with the solvent water molecules in aqueous solution. Multiple conformations (gg and gt) exist for the exocyclic hydroxymethyl groups. The results of the MD simulations are compared with those of 1H-1H nuclear Overhauser effect measurements.


Assuntos
Dissacarídeos/química , Configuração de Carboidratos , Sequência de Carboidratos , Simulação por Computador , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Dados de Sequência Molecular , Software , Soluções , Solventes , Fatores de Tempo
15.
Dent Mater J ; 14(2): 135-42, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8940552

RESUMO

Mixed salines, 3-methacryloxypropylsilytriisocyanate and 3-mercaptopropyltrimethoxysilane, were used as primers for adhesion of poly(methyl methacrylate) to porcelain teeth, precious alloys and nonprecious alloys. After thermocycle testing, the mean bond strength of the resin to porcelain, silver alloys and stainless steel were excellent. The fracture patterns of porcelain teeth after thermocycling followed by adherent testing were similar to those of specimens subjected to 48-hour water immersion at 37 degrees C. Two specimens failed cohesively in the porcelain and the other specimens failed in the resin. The mixed primer had no effect on cobalt-chromium alloy specimens.


Assuntos
Ligas Dentárias , Colagem Dentária , Cimentos Dentários/química , Porcelana Dentária , Silanos/química , Compostos de Boro , Ligas de Cromo , Ligas de Ouro , Teste de Materiais , Metacrilatos/química , Metilmetacrilatos , Prata , Aço Inoxidável , Resistência à Tração
16.
Dent Mater J ; 16(1): 21-30, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9549998

RESUMO

To improve the water sorption of poly(methyl methacrylate), new hydrophobic monomers, such as norbonyl and phenyl methacrylate, were studied to determine the resin with lower water sorption with no decrease in mechanical property. Water sorption of the copolymers of the hydrophobic monomers and MMA decreased with the increase in the concentration of the monomers. Compressive and bending strength of the copolymers were higher than that of PMMA, and the elastic modulus in bending was the same as that of PMMA. In addition, the transverse-deflection values satisfied ADA specifications. Dynamic mechanical thermal analysis of the copolymers showed a similar tendency to that of PMMA in spite of the introduction of bulky groups, such as norbonyl and phenyl, in the polymer molecule. The polymerization shrinkage in volume was in the following order: norbonyl < phenyl < methyl methacrylate.


Assuntos
Bases de Dentadura , Polimetil Metacrilato/química , Força Compressiva , Análise Diferencial Térmica , Elasticidade , Hidrólise , Teste de Materiais , Metacrilatos/química , Polímeros/química , Resistência à Tração , Molhabilidade
17.
Dent Mater J ; 12(1): 29-35, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8306603

RESUMO

To diminish the effect of water on the adhesive durability of lining cement, an experimental lining cement using a hydrophobic polymer as the cement liquid was studied. The polymers were styrene-butadien-alkyl acrylate copolymer (SBA copolymer) and carboxylated styrene-butadien-alkyl acrylate copolymer (CSBA copolymer) and were used as aqueous emulsions. The cement powder consisted of alkaline silicate and calcium disilicate. The pH values of the immersion water of the cement prepared from emulsion of SBA copolymer (SBA cement) was almost the same as that of calcium hydroxide cement. The compressive and diametral tensile strengths of SBA cement gradually increased over time in water. The bond strengths of cement prepared from the CSBA copolymer emulsion containing five percent carboxyl groups by weight were superior to those of calcium hydroxide cement.


Assuntos
Resinas Acrílicas/química , Colagem Dentária , Forramento da Cavidade Dentária , Cimentos Dentários/química , Poliestirenos/química , Animais , Bovinos , Concentração de Íons de Hidrogênio , Teste de Materiais , Resistência à Tração , Água
18.
Kyobu Geka ; 45(7): 644-6, 1992 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-1619832

RESUMO

A male neonate, two days of age, was admitted with cyanosis and tachypnea. Chest roentgenograms showed massive cardiomegaly and decreased pulmonary vasculatures. Echocardiographic and the right ventriculographic findings were interpreted as showing primary pulmonary atresia with secondary tricuspid incompetence. At a Brock operation, however, there was no resistance in passing the instrument through the pulmonary valve. The baby died twelve hours after surgery. Postmortem examination showed that the tricuspid regurgitation was a cause of the functional pulmonary atresia (FPA). It is important to distinguish FPA from pure pulmonary atresia because conservative therapy is the first choice for the FPA.


Assuntos
Valva Pulmonar/anormalidades , Diagnóstico Diferencial , Ecocardiografia , Humanos , Recém-Nascido , Masculino , Valva Pulmonar/diagnóstico por imagem , Valva Pulmonar/patologia , Insuficiência da Valva Tricúspide/complicações
19.
J Phys Condens Matter ; 26(3): 035402, 2014 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-24351274

RESUMO

We present a genetic algorithm (GA) for structural search that combines the speed of structure exploration by classical potentials with the accuracy of density functional theory (DFT) calculations in an adaptive and iterative way. This strategy increases the efficiency of the DFT-based GA by several orders of magnitude. This gain allows a considerable increase in the size and complexity of systems that can be studied by first principles. The performance of the method is illustrated by successful structure identifications of complex binary and ternary intermetallic compounds with 36 and 54 atoms per cell, respectively. The discovery of a multi-TPa Mg-silicate phase with unit cell containing up to 56 atoms is also reported. Such a phase is likely to be an essential component of terrestrial exoplanetary mantles.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA