Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Molecules ; 27(6)2022 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-35335354

RESUMO

The impact of the charge transfer complex on the dielectric relaxation processes in free poly(methyl methacrylate) (PMMA) polymer sheets was investigated. The frequency dependence of dielectric properties was obtained over the frequency range 0.1 Hz-1 MHz at temperatures ranging between 303 K and 373 K for perylene dye and acceptors (picric acid (PA) and chloranilic acid (CLA)) in an in situ PMMA polymer. The TG/dTG technique was used to investigate the thermal degradation of the synthesized polymeric sheets. Additionally, the kinetic parameters have been assessed using the Coats-Redfern relation. The dielectric relaxation spectroscopy of the synthesized polymeric sheets was analyzed in terms of complex dielectric constant, dielectric loss, electrical modulus, electrical conductivity, and Cole-Cole impedance spectroscopy. α- and ß-relaxation processes were detected and discussed. The σ(ω) dispersion curves of the synthesized polymeric sheets show two distinct regions with increasing frequency. The impedance data of the synthesized polymeric sheets can be represented by the equivalent circuit (parallel RC).

2.
Reprod Toxicol ; 9(4): 379-87, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7496094

RESUMO

Technical grade methoxychlor (MXC) is an estrogenic pesticide currently used for pest control in the US. To determine the long-term effects of technical MXC on ovaries and estrous cycles, neonatal mice received 14 daily intraperitoneal injections of sesame oil only, 10.0 micrograms estradiol-17 beta, or 0.05 mg, 0.1 mg, 0.5 mg, or 1.0 mg of technical MXC. At 3, 6, and 12 months, vaginal smears were examined for 12 d and ovaries collected. All technical MXC doses and estradiol increased the duration of vaginal cornification but only estradiol, 0.5, or 1.0 mg technical MXC induced ovarian atrophy, relative ovarian weight loss, and depletion of corpora lutea. Technical MXC doses of 0.05 or 0.1 mg produced the opposite effects; the ovaries remained heavy, large, and filled with corpora lutea. On the other hand, follicular cysts were recorded in all groups, except the 1.0 mg MXC group. These augmentary and inhibitory effects of MXC at low and high doses mimic the estrogen effects at low and high doses, and were probably due to the altered hypothalamic-hypophyseal function.


Assuntos
Animais Recém-Nascidos/fisiologia , Inseticidas/toxicidade , Metoxicloro/toxicidade , Ovário/patologia , Animais , Peso Corporal/efeitos dos fármacos , Estradiol/farmacologia , Estro/efeitos dos fármacos , Feminino , Camundongos , Tamanho do Órgão/efeitos dos fármacos , Gravidez , Vagina/patologia
3.
Artigo em Inglês | MEDLINE | ID: mdl-21514212

RESUMO

The optimized geometry and vibrational frequencies of P-N,N-dimethylaminobenzylidenemalononitrile (DBM) were obtained by ab initio HF and DFT/B3LYP levels with complete relaxation in the potential energy surface using 6-31++G(d,p) and 6-311++G(d,p) basis sets. The Fourier-transform infrared (FT-IR) spectrum of DBM has been recorded in the region 4000-400 cm(-1). The harmonic vibrational frequencies were calculated and the scaled values have been compared with experimental FT-IR spectrum. The calculated frequencies are in good agreement with the experimental frequencies.


Assuntos
Compostos de Benzilideno/química , Nitrilas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Modelos Moleculares , Teoria Quântica
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 79(5): 1499-504, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21640638

RESUMO

P-N,N-dimethylaminobenzylidenemalononitrile (DBM) dye belongs to a class of organic compounds known as molecular rotors. Its optimized geometry and frontier molecular orbitals (FMOs), before and after ultraviolet (UV) irradiation, were obtained by DFT/B3LYP level with complete relaxation in the potential energy surface using 6-311++G(d,p) basis set. It is found that the length of C-C bonds of the DBM molecule increases after the UV irradiation, which leads to an increase in its dipole moment making it as a promising material for solar cell applications. Also, its HOMO-LUMO gap decreased from 3.46 to 3.34 eV. From the cyclic voltammetry measurements the value of HOMO-LUMO gap is equal to 3.21 eV. This means that B3LYP/6-311++G(d,p) level of theory is the best one for calculations.


Assuntos
Compostos de Benzilideno/química , Modelos Químicos , Modelos Teóricos , Nitrilas/química , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular , Teoria Quântica
5.
Dev Biol Stand ; 56: 573-8, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6489632

RESUMO

Blood and urine samples were collected from 50 patients with febrile splenomegaly suspected to be Malta fever in Sharkia fever hospitals, Egypt. Blood samples were subjected to isolation of Brucellae; blood counts and erythrocyte sedimentation rate. Urine analysis. Four strains of brucella were isolated. Two of these isolated first from the 50 patients and typed as Br. melitensis Biotype I and the others were recovered secondly and thirdly from serologically positive patients and typed as Br. abortus Biotype I. All the strains from positive serology, titre ranging from 1/160-1/640. Br. melitensis is more readily isolated from the blood than Br. abortus. Blood picture of serologically positive Malta fever showed three patients with mild leukopenia; two with relative lymphocytosis; two with secondary anaemia and three with accelerated erythrocyte sedimentation rate. Urine analysis revealed five patients with albuminuria.


Assuntos
Brucella/isolamento & purificação , Brucelose/microbiologia , Brucella/classificação , Brucelose/sangue , Brucelose/urina , Humanos , Esplenomegalia/microbiologia
6.
Dev Biol Stand ; 56: 565-72, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6436114

RESUMO

50 Blood samples were collected from in-patients with febrile splenomegaly suspected to be Malta fever, in Sharkia fever hospitals; Egypt. The samples were subjected to serological tests (tube agglutination, Widal & Coombs) for diagnosis of brucellosis. The results of tube agglutination (TAT) revealed that 5 (10%) were positive; the titre ranging from 1/80-1/320, 3 doubtful (1/40) and 42 negative (1/20, 1/10 and no agglutination). Results of the Coombs test on negative and doubtful of TAT showed that out of 45 patients; 3 (6.66%) were positive; the titre ranging from 1/80-1/160, one doubtful and 41 negative. Coombs test improved the titre of one positive case of TAT from 1/320-1/640. Results of serological tests (TAT & Coombs) for MALTA fever were 8 (16%); the titre ranging from 1/80-1/640, one doubtful (1/40) and 41 negative. Results of the Widal test to detect Enteric fever in the way of differential diagnosis were 7 (14%) positive out of 50 patients examined; the titre ranging from 1/80-1/160. Five of them agglutinated typhoid (O&M) suspensions. One of the sera agglutinated paratyphi A (H) suspension, the remaining one serum agglutinated paratyphi. B(H) suspension and none of the sera agglutinated paratyphi. C(H) suspension. All the positive Coombs and negative Widal cases were obtained against typhoid (O) suspension and none against any of the (H) suspensions; Coombs test was positive in two (4.65) of 43 patients negative to Widal; no improvement of titre in the positive Widal. Results of Widal & Coombs to detect Enterica were 9 (18%) positive and 41 negative.


Assuntos
Brucelose/diagnóstico , Anticorpos Antibacterianos/análise , Brucella abortus/imunologia , Diagnóstico Diferencial , Humanos , Salmonella paratyphi A/imunologia , Salmonella paratyphi B/imunologia , Salmonella paratyphi C/imunologia , Salmonella typhi/imunologia , Testes Sorológicos , Esplenomegalia/diagnóstico , Febre Tifoide/diagnóstico
7.
Anat Rec ; 247(2): 189-98, 1997 02.
Artigo em Inglês | MEDLINE | ID: mdl-9025998

RESUMO

BACKGROUND: The occurrence of encapsulated sensory receptors in extrinsic ocular muscles differs among and within orders of mammals. Beyond indications that neuromuscular and neurotendinous spindles are present in extraocular muscles of the family Camilidae, little is known of their distributional characteristics. In fact there appear to be no distribution maps for any animal that show both major types of encapsulated muscle receptor in a full set of intraorbital skeletal muscles. METHOD: Serial histological sections of all skeletal muscles from one orbit of an adult, one-humped camel (Camelus dromedarius) were examined for encapsulated receptors. RESULTS: Encapsulated receptors were apparent in all the intraorbital skeletal muscles. Muscle spindles outnumbered tendon organs in the fleshy part of each muscle. For all muscles, spindles were most abundant in the half of the muscle near the origin; levator palpebrae superioris had a more even distribution of spindles along its length than did extraocular muscles. These longitudinal patterns of distribution for muscle spindles related in a general way to the nerve entry zone. Tendon organs occurred anywhere along a muscle's length, but they tended to be more frequent on either side of the major concentration of muscle spindles. Both types of encapsulated receptors were generally located nearer the perimeter than the center of cross sections through muscles. CONCLUSIONS: Encapsulated receptors of classic appearance are plentiful and have distinctive configurations within intraorbital skeletal muscles of the adult dromedary. When analyzed in conjunction with other studies, the present data give rise to testable explanations for the variability among genera in the number of encapsulated receptors in extraocular muscles.


Assuntos
Camelus/anatomia & histologia , Mecanorreceptores/citologia , Fusos Musculares/citologia , Músculo Esquelético/anatomia & histologia , Órbita , Animais , Tamanho Celular , Masculino , Tamanho do Órgão
8.
Fundam Appl Toxicol ; 17(4): 733-45, 1991 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1778360

RESUMO

Adult male Sprague-Dawley rats (100 days of age) were given single oral doses of the fungicide benomyl (methyl 1-(butylcarbamoyl)-2- benzimidazolecarbamate) in dosages ranging from 25 to 800 mg/kg body weight. The testis and excurrent ducts were examined at 2 and 70 days posttreatment to determine the chemical effects on spermatogenesis and the epididymis. Primary effects seen at 2 days postexposure were testicular swelling and occlusions of the efferent ductules. Mean testis weight peaked with 400 mg/kg. Premature release of germ cells (sloughing), detected even with the lowest dosage (25 mg/kg), was the most sensitive short-term response to benomyl. Sloughing was found primarily in Stage VII of the spermatogenic cycle at the lower dosages, but at higher dosages sloughing extended into all stages except for Stages VIII-XI. Occlusions of the efferent ductules of the testis were dose-dependent and correlated with testis weight. Sperm and sloughed germ cells were compacted in the ductal lumen of occluded ductules, which were surrounded by two to four layers of polymorphonuclear leukocytes and other inflammatory cells. Although the caput epididymidis contained sloughed germ cells and appeared swollen, evidence of permanent occlusion was not found. The long-term (70 days) effects of benomyl were decreased testis weight (at 400 mg/kg), dose-dependent increases in seminiferous tubular atrophy, and increases in the number of reproductive tracts containing occluded efferent ductules. Fibrosis, granulomas, and abnormal growth were long-term consequences of occluded ductules, which were present 100% of the time in testes containing 26-100% seminiferous tubular atrophy. Only a few testes were found to be completely regressed. Occlusion of efferent ductules and disruption of the seminiferous epithelium by sloughing of germ cells are overlapping dose-dependent mechanisms responsible for short- and long-term effects of benomyl on the rat testis.


Assuntos
Benomilo/toxicidade , Células Germinativas/efeitos dos fármacos , Túbulos Seminíferos/efeitos dos fármacos , Doenças Testiculares/induzido quimicamente , Animais , Atrofia/induzido quimicamente , Atrofia/patologia , Epididimo/efeitos dos fármacos , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Endogâmicos , Túbulos Seminíferos/patologia , Espermatogênese/efeitos dos fármacos , Doenças Testiculares/patologia , Doenças Testiculares/fisiopatologia , Testículo/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA