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1.
J Chem Phys ; 145(3): 034702, 2016 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-27448899

RESUMO

We have investigated the charge transfer mechanism in single crystals of DTBDT-TCNQ and DTBDT-F4TCNQ (where DTBDT is dithieno[2,3-d;2',3'-d'] benzo[1,2-b;4,5-b']dithiophene) using a combination of near-edge X-ray absorption spectroscopy (NEXAFS) and density functional theory calculations (DFT) including final state effects beyond the sudden state approximation. In particular, we find that a description that considers the partial screening of the electron-hole Coulomb correlation on a static level as well as the rearrangement of electronic density shows excellent agreement with experiment and allows to uncover the details of the charge transfer mechanism in DTBDT-TCNQ and DTBDT-F4 TCNQ, as well as a reinterpretation of previous NEXAFS data on pure TCNQ. Finally, we further show that almost the same quality of agreement between theoretical results and experiment is obtained by the much faster Z+1/2 approximation, where the core hole effects are simulated by replacing N or F with atomic number Z with the neighboring atom with atomic number Z+1/2.

2.
J Phys Condens Matter ; 30(38): 385801, 2018 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-30113013

RESUMO

Single crystals of HoIr2Si2 with the body-centered ThCr2Si2-type structure (I4/mmm) were grown by Bridgman method from indium flux. Single crystal structure determination yielded a Si-z position of 0.378(1) in the structure. We excluded the presence of the high temperature phase with the primitive CaBe2Ge2-type structure (P4/nmm) by powder x-ray diffraction. Magnetic measurements on the single crystals yield a Néel temperature of [Formula: see text] K. In the inverse magnetic susceptibility a strong anisotropy with Weiss temperatures [Formula: see text] K and [Formula: see text] K occurs above T N. The effective magnetic moment [Formula: see text] and [Formula: see text] is close to the expected value for a free Ho3+ ion, [Formula: see text]. The field dependent magnetization shows a step-like behaviour due to crystalline electric field effects. The temperature and field dependence of the magnetization hint to the ordering of the magnetic moments along the c direction below T N.

4.
Dalton Trans ; 46(27): 8769-8773, 2017 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-28243656

RESUMO

The thermo-labile triazenide Na[tBu3SiNNNSiMe3] was prepared by the reaction of Me3SiN3 with Na(thf)2[SitBu3] in pentane at -78 °C. Treatment of Na[tBu3SiNNNSiMe3] with an excess of carbon dioxide in pentane at -78 °C yielded the imido carbonate (tBu3SiO)(Me3SiO)C[double bond, length as m-dash]N-SitBu3 and the carbamine acid (tBu3SiO)CONH2 along with other products. From the reaction solution we could isolate the imido carbonate (tBu3SiO)(Me3SiO)C[double bond, length as m-dash]N-SitBu3 and carbamine acid (tBu3SiO)CONH2. At first single crystals of the carbamine acid (tBu3SiO)CONH2 (triclinic, space group P1[combining macron]) were grown from this solution at room temperature. A second crop of crystals were obtained by concentrating the solution. The second charge consisted of the imido carbonate (tBu3SiO)(Me3SiO)C[double bond, length as m-dash]N-SitBu3 (monoclinic, space group P21/n).

5.
Biol Psychiatry ; 36(3): 180-8, 1994 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-7948455

RESUMO

In a randomized, parallel design, 19 patients with winter depression were treated with either a week of a white 1.5-hr dawn simulation peaking at 250 lux or a week of a red, 1.5-hr dawn signal peaking at 2 lux. The subjects were told that they would receive either a white or red dawn reaching in intensity that would be dimmer than standard bright light treatment. At the end of both the baseline week and the treatment week subjects were blindly assessed with the Hamilton Rating Scale for Depression (HDRS). Analysis of covariance was used to compare the two dawn treatments. The white, 1.5-hr, 250 lux dawn simulation resulted in significantly (p < 0.05) lower HDRS scores compared to the red, 1.5-hr, 2 lux dawn. This is the second controlled study which indicates that dawn simulation is an effective treatment for winter depression.


Assuntos
Fototerapia/métodos , Transtorno Afetivo Sazonal/terapia , Adulto , Ritmo Circadiano , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inventário de Personalidade , Transtorno Afetivo Sazonal/psicologia , Fases do Sono
6.
Biol Psychiatry ; 50(3): 205-16, 2001 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-11513820

RESUMO

BACKGROUND: Some small controlled studies have found that dawn simulation is effective in treating seasonal affective disorder (SAD). With a larger sample size and a longer duration of treatment, we compared dawn simulation with bright light therapy and a placebo condition in patients with SAD. METHOD: Medication-free patients with SAD were randomly assigned to one of three conditions: bright light therapy (10,000 lux for 30 min, from 6:00 AM to 6:30 AM), dawn simulation (1.5 hour dawn signal from 4:30 AM to 6:00 AM peaking at 250 lux), and a placebo condition, a dim red light (1.5 hour dawn signal from 4:30 am to 6:00 AM peaking at 0.5 lux.) Over the subsequent 6 weeks, the subjects were blindly rated by a psychiatrist using the Structured Interview Guide for the Hamilton Depression Rating-Seasonal Affective Disorder Version (SIGH-SAD). We modeled the profiles of the remissions (SIGH-SAD < or = 8) and response (> or =50% decrease in SIGH-SAD) to treatment over time using Cox proportional hazards models. RESULTS: The sample consisted of 95 subjects who were randomized to the three conditions: bright light (n = 33), dawn simulation (n = 31) and placebo (n = 31). Dawn simulation was associated with greater remission (p <.05) and response (p <.001) rates compared to the placebo. Bright light did not differ significantly from the placebo. Dawn simulation was associated with greater remission (p <.01) and response (p <.001) rates compared to the bright light therapy. The mean daily hours of sunshine during the week before each visit were associated with a significant increase in likelihood of both remission (p <.001) and response (p <.001). CONCLUSIONS: Dawn simulation was associated with greater remission and response rates compared to the placebo and compared to bright light therapy. The hours of sunshine during the week before each assessment were associated with a positive clinical response.


Assuntos
Ritmo Circadiano/fisiologia , Fototerapia , Transtorno Afetivo Sazonal/terapia , Adulto , Feminino , Humanos , Masculino , Estudos Retrospectivos
7.
Am J Psychiatry ; 150(1): 113-7, 1993 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8417552

RESUMO

OBJECTIVE: This study sought to determine whether dawn simulation was superior to a shorter dimmer "placebo" dawn signal in treating winter depression. METHOD: In a randomized, parallel design, 22 patients with winter depression were treated with either 1 week of a 2-hour dawn simulation peaking at 250 lux or 1 week of a 30-minute dawn simulation peaking at 0.2 lux. The subjects were told that they would receive either a "gradual" dawn or a "rapid" dawn reaching an intensity that would be dimmer than standard bright light treatment. At the end of both the baseline week and the treatment week, subjects were assessed in a blind manner with the Hamilton Rating Scale for Depression. Analysis of covariance was used to compare the two dawn treatments. RESULTS: The 2-hour, 250-lux dawn simulation resulted in Hamilton depression scale scores that were significantly lower than scores after the 30-minute, 0.2-lux dawn simulation. CONCLUSIONS: This study indicates that dawn simulation is an effective treatment for winter depression.


Assuntos
Fototerapia/métodos , Transtorno Afetivo Sazonal/terapia , Adulto , Ritmo Circadiano , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/psicologia , Transtorno Depressivo/terapia , Feminino , Humanos , Masculino , Placebos , Escalas de Graduação Psiquiátrica , Transtorno Afetivo Sazonal/diagnóstico , Transtorno Afetivo Sazonal/psicologia , Luz Solar
8.
Placenta ; 22(7): 639-45, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11504532

RESUMO

CD133 is a protein expressed on the cell membrane of a subfraction of haematopoietic stem and progenitor cells, as well as on some epithelial cells. Previously available antibodies against CD133 recognized only the glycosylated protein, localized to membrane protrusions or microvilli. Due to this, immature intracellular stages of the CD133 protein could not be visualized using these antibodies. We describe reactivity of a commercially available antibody against CD133, called AC133-2, with an intracellular protein in trophoblast. Both villous and extravillous cytotrophoblast, as well as syncytiotrophoblast were stained by AC133-2 in cryostat sections of first trimester and term placenta. Villous stroma was not stained. AC133-2 reactivity was seen in methanol-fixed primary trophoblast cells and trophoblast-derived cell lines, and was coexpressed with cytokeratin-7. CD133 messenger RNA was present in trophoblast and trophoblast-derived cell lines, but also in cells not displaying any reactivity with CD133 antibodies. AC133-2 recognized a 55-60 kDa protein on Western blots of cell extracts including trophoblast. The exact nature of this protein is not yet understood. However, AC133-2 is applicable as a positive marker for the characterization of all subtypes of trophoblast and for trophoblast cell lines.


Assuntos
Anticorpos Monoclonais/imunologia , Biomarcadores/análise , Glicoproteínas/análise , Peptídeos/análise , Proteínas/análise , Proteínas/imunologia , Trofoblastos/química , Antígeno AC133 , Especificidade de Anticorpos , Antígenos CD , Western Blotting , Linhagem Celular , Coriocarcinoma , Epitopos/imunologia , Feminino , Glicoproteínas/genética , Glicoproteínas/imunologia , Humanos , Células Híbridas , Imuno-Histoquímica , Queratina-7 , Queratinas/análise , Peptídeos/genética , Peptídeos/imunologia , Gravidez , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas
9.
J Clin Psychiatry ; 59(1): 36-42; quiz 43-4, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9491067

RESUMO

BACKGROUND: Recent data suggest that winter depression (seasonal affective disorder [SAD]) may be a subtype of affective disorder that is closely related to alcoholism. Dawn simulation has been shown in controlled trials to be effective in SAD. The present study examined the effectiveness of dawn simulation in abstinent alcoholics who met DSM-III-R criteria for major depression, or bipolar disorder, depressed with seasonal pattern. METHOD: All 12 subjects with winter depression had a history of either alcohol dependence or alcohol abuse according to DSM-III-R and had been abstinent from alcohol for at least 6 months. They also fulfilled criteria for SAD according to Rosenthal and were hypersomnic and drug free. After a 1-week baseline period, the subjects were randomly assigned to a 1-week treatment period at home with either a white 1.5-hour dawn from 4:30 a.m. to 6:00 a.m. peaking at 250 lux or a red 1.5-hour dawn from 4:30 a.m. to 6:00 a.m. peaking at 2 lux. The subjects were told that they would receive daily either a red or a white dawn reaching the same illuminance, an illuminance that would be much dimmer than standard bright light treatment. At the end of each week, the subjects were blindly assessed by a psychiatrist using the Structured Interview Guide for the Hamilton Depression Rating Scale-Seasonal Affective Disorder version (SIGH-SAD). RESULTS: For the 6 subjects completing the white dawn treatment, the mean SIGH-SAD score decreased from 33.0 at baseline to 15.8 after treatment. For the 6 subjects completing the dim red dawn treatment, the mean SIGH-SAD score decreased from 34.3 to 32.7. The mean post-dawn SIGH-SAD score was significantly lower after the white dawn treatment than after the dim red dawn treatment (ANCOVA with baseline SIGH-SAD as the covariate, F = 12.95, p < .01). Superiority of the white dawn was also found by analogous analyses for the Hamilton Rating Scale for Depression (HAM-D) (p < .01) and the SAD Subscale (p < .05). CONCLUSION: The present study suggest that dawn simulation may be helpful in decreasing depression in abstinent alcoholics with SAD. Further study is necessary to confirm these preliminary findings and to determine whether dawn simulation might be helpful in preventing relapse in abstinent alcoholics who have SAD.


Assuntos
Alcoolismo/complicações , Luz , Fototerapia/métodos , Transtorno Afetivo Sazonal/terapia , Adulto , Alcoolismo/psicologia , Alcoolismo/reabilitação , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/psicologia , Transtorno Bipolar/terapia , Ritmo Circadiano , Feminino , Humanos , Masculino , Placebos , Escalas de Graduação Psiquiátrica , Recidiva , Transtorno Afetivo Sazonal/diagnóstico , Transtorno Afetivo Sazonal/psicologia , Sono/fisiologia , Temperança , Resultado do Tratamento
10.
J Clin Psychiatry ; 53(10): 359-63, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1429475

RESUMO

BACKGROUND: Bright light therapy has been shown to be effective in treating winter depression. Dawn simulation, a low-illuminance light that gradually increases in intensity while the person sleeps, decreased depression in an uncontrolled study. The present study compares a gradual dawn signal with a hypothesized placebo condition, a rapid dawn signal. METHOD: In a 4-week, randomized crossover design, nine patients with winter depression were treated with a gradual, 2.5-hour dawn simulation for 1 week and a rapid, 10-minute dawn simulation for 1 week. Both dawns had a maximum illuminance of 275 lux. At the end of each baseline week and treatment week, blind raters assessed the level of depression. RESULTS: Hamilton Rating Scale for Depression mean scores significantly decreased for both the gradual dawn (17.7 to 5.9, p < .05) and the rapid dawn (17.2 to 7.0, p < .05) condition. The improvement was similar for both treatments. Early morning awakening was significantly (p < .01) more common with the gradual dawn (7/9) than with the rapid dawn (1/9) condition. CONCLUSION: Depression decreased under both dawn simulations. Because the degree of improvement was similar, a placebo effect rather than the efficacy of dawn simulation might explain the results. However, a mere placebo effect is an unlikely explanation. The degree of improvement was similar to that shown in studies of bright light therapy and clearly superior to previous "placebo" control conditions. The side effects from the gradual dawn may have obscured a potential superiority of the gradual dawn over the rapid dawn.


Assuntos
Ritmo Circadiano , Fototerapia/métodos , Transtorno Afetivo Sazonal/terapia , Adolescente , Adulto , Feminino , Humanos , Iluminação , Masculino , Pessoa de Meia-Idade , Efeito Placebo , Escalas de Graduação Psiquiátrica , Transtorno Afetivo Sazonal/diagnóstico , Transtorno Afetivo Sazonal/psicologia , Índice de Gravidade de Doença , Sono , Resultado do Tratamento , Vigília
11.
Behav Res Ther ; 32(7): 747-51, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7980361

RESUMO

We tested the hypothesis that the perceived availability of safety resources plays an influential role in fear prediction bias. Claustrophobic Ss (N = 37) completed a claustrophobic challenge under conditions of either low or high proximity to safety. Proximity to safety was operationalized as distance from the exit. We examined the effects of proximity to safety on Ss' predicted fear, actual fear, and discrepancy between predicted and actual fear (prediction bias). Consistent with prediction, the availability of safety resources had a more pronounced effect on Ss' actual fear than Ss' predicted fear. Moreover, subjects displayed a significant underprediction bias when proximity to safety was low and a slight (albeit nonsignificantly) overprediction bias when proximity to safety was high. Our results lend further support for the hypothesis that anxious Ss underutilize safety information when confronting perceived threats. Possible mechanisms underlying this tendency are discussed.


Assuntos
Medo , Transtornos Fóbicos/psicologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Modelos Psicológicos , Probabilidade
12.
Carbohydr Res ; 336(4): 297-308, 2001 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-11728398

RESUMO

Regioselective epoxide ring opening of 2(I),3(I)-(2(I)S)-anhydro-alpha-cyclodextrin (1) through intramolecular attack of hydroxyl groups of neighboring glucose rings occurs in diequatorial fashion to yield 3(I),2(II)-anhydro-alpha-cyclodextrin (3) with a rigid glucopyranose-dioxane-glucopyranose tricyclic ring system, the usual diaxial opening and the gluco/altro-configured stereoisomer 2 cannot be detected. Molecular dynamic simulations in water were used to analyze the conformations of 1-3 and the stereochemical implications of this reaction. Due to the contracted 2,3-OH side of the torus, 3 features an inverted conicity compared to the parent alpha-cyclodextrin. A crystallographic study on the bis-3.3 n-PrOH nonahydrate not only displays little variations between the solid-state and solution geometries of 3, but also provides a molecular picture of a unique inclusion complex in which three n-propanol molecules are distributed in the cavity of a dimeric unit of 3 (monoclinic, space group P2(1), a=14.257(1), b=22.623(2), c=16.644(1) A, beta=104.82(1) degrees, all 19,278 reflections with I>2 sigma(I) yield R(F)=0.1017).


Assuntos
Ciclodextrinas/química , Simulação por Computador , Cristalografia por Raios X , Compostos de Epóxi , Ligação de Hidrogênio , Modelos Moleculares , Estrutura Molecular , Movimento (Física) , Estereoisomerismo , Termodinâmica
13.
Psychiatr Serv ; 46(4): 347-52, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7788455

RESUMO

Despite the increasing demand for outcome assessment measures, no published reports have provided a standardized way to assess psychiatric inpatients that includes diagnosis and observer ratings of psychopathology. This paper reviews general principles for selecting outcome assessment measures, proposes a battery of instruments based on already available measures to assess clinical status in psychiatric inpatients, reviews methods of implementing the battery in an academic inpatient psychiatric setting, and presents preliminary data on its interrater reliability, construct validity, and range of response to acute hospitalization. Preliminary results suggest that the battery may be useful for resident and medical student education and for enhancing quality assurance and continuous quality improvement.


Assuntos
Transtornos Mentais/diagnóstico , Admissão do Paciente , Equipe de Assistência ao Paciente , Determinação da Personalidade/estatística & dados numéricos , Garantia da Qualidade dos Cuidados de Saúde , Comorbidade , Estudos de Viabilidade , Humanos , Transtornos Mentais/psicologia , Transtornos Mentais/terapia , Avaliação de Processos e Resultados em Cuidados de Saúde , Psicometria , Reprodutibilidade dos Testes
14.
Chemosphere ; 42(4): 361-6, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11100786

RESUMO

The transformation of 3-chlorophenol (3CP) photoinduced by iron(II) in aqueous solution has been investigated under monochromatic irradiation (lambda(exc) = 365 nm) representative of atmospheric solar emission. Hydroxyl radicals are formed via an intramolecular photoredox process in iron(III) excited hydroxy-complexes. Fe(OH)2+ is the most active complex in terms of HO* formation and according to our experiments and calculations, it appears that Fe(OH)2+ is the only iron(III) species involved in 3CP oxidation process. Hydroxyl radicals react very rapidly with 3CP, which is eliminated from the solution. The primary intermediates do not accumulate in the medium but rapidly degraded to non-absorbing compounds by a subsequent action of hydroxyl radicals.


Assuntos
Clorofenóis/química , Compostos Ferrosos/química , Hidrólise , Oxirredução , Fotoquímica , Soluções
15.
Chemosphere ; 41(3): 363-70, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11057598

RESUMO

The Fe(III)-photoinduced degradation of 4-dodecylbenzenesulphonate (DBS) in aqueous solution was investigated. The mixing of DBS (1 mm) and Fe(III) (1 mm) solutions immediately led to the formation of a precipitate that contained DBS and monomeric Fe(OH)2+, the predominant Fe(III) species. Both species were also present in the supernatant. Irradiation of the supernatant solution resulted in a photoredox process that yielded Fe(II) and *OH radicals. The disappearance of DBS was shown to involve only attack by *OH radicals; the quantum yield of DBS disappearance is similar to the quantum yield of *OH radical formation. A wavelength effect was also observed; the rate of DBS disappearance was higher for shorter wavelength irradiation. Five photoproducts, all containing the benzene sulphonate group, were identified. *OH radicals preferentially abstract hydrogen from the carbon in the alpha position of the aromatic ring. The results show that the Fe(III)-photoinduced degradation of DBS could be used as an alternative method for polluted water treatment.


Assuntos
Benzenossulfonatos/química , Compostos Férricos , Tensoativos/química , Poluentes Químicos da Água , Purificação da Água , Benzenossulfonatos/efeitos da radiação , Humanos , Fotoquímica , Soluções , Luz Solar , Tensoativos/efeitos da radiação , Água
16.
Chemosphere ; 40(4): 395-401, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10665405

RESUMO

The photoinduced degradation of an alcohol ethoxylate (AE) (Brij 30) by Fe(III) in aqueous solution has been investigated. The study was carried out with the major fraction of ethoxymers having an alkyl chain length of 12 carbon atoms and n ethoxy units E (C12En). The Fe(III) sensitised degradation of this fraction occurs efficiently at 365 nm. The rate of degradation depends on the concentration of Fe(OH)2+, the most photoreactive species in terms of .OH radical formation. Formate ethoxylates were identified as photoproducts and shortening of the ethoxylated chain all along the degradation process was observed. The mechanism of Brij 30 degradation implies a major .OH radicals attack on the polyethoxylated chain. For prolonged irradiations, the total degradation of Brij 30 and of the photoproducts is obtained. Consequently, the degradation photoinduced by iron (III) could be an efficient method of AEs removal in water.


Assuntos
Detergentes/química , Polietilenoglicóis/química , Poluentes Químicos da Água , Radical Hidroxila , Ferro , Cinética , Polidocanol , Soluções , Água
17.
Biotech Histochem ; 72(5): 243-8, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9408583

RESUMO

A procedure is presented for exact, detailed comparison of light and electron microscopic analyses of tissues with complex architecture. Earlier techniques require one to make drawings of tissue pieces to be analyzed by electron microscopy to permit rough localization of the origin of the tissue pieces. Specifically, exact analysis of fetal cartilage and bone is hampered by the complicated arrangement of both tissue components, severely limiting the assessment of electron microscopic analyses. The advantage of the technique described here is that it allows precise localization of the tissue sample in the original tissue area. Punches 1 min in diameter were obtained from femora and coxae with a syringe and embedded for light and electron microscopy. The remaining tissue with its exactly defined punctures is prepared for standard histology. Human fetal cartilage and bone tissue were used to demonstrate this technique, but this procedure may be used for other kinds of tissues.


Assuntos
Biópsia por Agulha/métodos , Osso e Ossos/ultraestrutura , Cartilagem/ultraestrutura , Biópsia por Agulha/instrumentação , Células da Medula Óssea/ultraestrutura , Osso e Ossos/citologia , Cartilagem/citologia , Feminino , Lâmina de Crescimento/citologia , Lâmina de Crescimento/ultraestrutura , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Luz , Microscopia , Microscopia Eletrônica , Microtomia , Inclusão do Tecido
18.
Ann Anat ; 182(5): 415-22, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11035635

RESUMO

The resorption of teeth in Ambystoma mexicanum during postembryonal ontogenesis and induced metamorphosis occurs by means of light-microscopic detectable giant-cells. These have morphological and functional characters similar to those of odontoclasts of other vertebrates. The multinucleated odontoclasts resorb not only the pedicel (base), but the stalk of the tooth, too. When active, the cells form a ruffled border and a sealing zone. In this way they are able to demineralize the hard tissues of teeth (dentin and mineral of the pedicel) and to dissolve the extracellular matrix. Resorption of enamel has not been observed. Marks of resorption resemble the Howship's lacunae of other tetrapods. TRAP as a typical enzyme of odontoclasts could not be detected histochemically. Dependence of PTH, which is supposed to be necessary for the formation and activation of odontoclasts as well as of thyroxine can be excluded, although the resorbing cells are functionally and cytologically identical with those of other vertebrates. This demands some other mechanism for the formation and regulation of the odontoclasts in A. mexicanum.


Assuntos
Ambystoma mexicanum/anatomia & histologia , Osteoclastos/citologia , Reabsorção de Dente , Ambystoma mexicanum/crescimento & desenvolvimento , Animais , Metamorfose Biológica , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Osteoclastos/ultraestrutura
19.
Ann Anat ; 178(1): 71-80, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8717330

RESUMO

The wall of the pulp cavity, fracture faces and the demineralized surfaces of teeth from larvae and adults of Ambystoma mexicanum were investigated by scanning electron microscopy (SEM). Calcium and phosphate contents were determined by microanalysis. The apical part of the tooth (crown, tooth apex) contains dentin canals. In the larva, these do not reach the enamel-dentin border but end below this border in front of a denser hard substance, possibly enameloid. The pedicel in the adult and the basal portion of the tooth in the larva (base) are without dentin canals. These parts of the teeth are characterized by longitudinally arranged collagen fibres as visualized on the demineralized surfaces. These observations indicate a congruency in early-larval and adult teeth between base and pedicel as well as apex and crown. This partition is also confirmed by the calcium and phosphate values which were identical in larvae and adults. Highest values are found in enamel and lowest values in the tooth-bearing bone. Calcium and phosphate content show a clear difference between dentin and the basal part of the tooth (pedicel and base). The ring-like dividing zone in the adult tooth is less well mineralized.


Assuntos
Ambystoma mexicanum/anatomia & histologia , Cálcio/análise , Polpa Dentária/química , Polpa Dentária/ultraestrutura , Fosfatos/análise , Dente/química , Dente/ultraestrutura , Animais , Dente Pré-Molar , Colágeno/análise , Esmalte Dentário/química , Esmalte Dentário/ultraestrutura , Dentina/química , Dentina/ultraestrutura , Microanálise por Sonda Eletrônica , Embrião não Mamífero , Microscopia Eletrônica de Varredura
20.
J Anim Sci ; 80(3): 609-16, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11890397

RESUMO

Our objective was to determine effects of dietary high-oleate (Oleate; 76% 18:1) or high-linoleate (Linoleate; 78% 18:2) safflower seeds on fatty acids in muscle and adipose tissue of feedlot lambs. White-faced ewe lambs (n = 36) were fed a beet pulp, oat hay, and soybean meal basal diet (Control), blocked by BW, and allotted randomly to dietary treatments. Cracked safflower seeds were used in isocaloric and isonitrogenous replacement of beet pulp, oat hay, and soybean meal so that Oleate and Linoleate diets contained 5.0% additional fat. Fatty acids were determined in semitendinosus, longissimus dorsi (longissimus), and adipose tissue from the tail head (tailhead adipose tissue), adjacent to the 12th rib (s.c. adipose tissue), and kidney and pelvic fat (KPH adipose tissue) depots. Fatty acid data were analyzed within muscle and adipose tissue as a split-block design. Single degree of freedom orthogonal contrasts were used to compare treatment effects. Average daily gain, feed efficiency, and carcass characteristics did not differ (P = 0.15 to 0.96) across dietary treatments. Adipose tissue saturated fatty acids were greater (P = 0.04) for Controls but were not different (P = 0.36) in muscle. Trans-vaccenic acid (18:1(trans-11)) increased (P < 0.0001) with safflower supplementation and was greater (P < 0.0001) in Linoleate than in Oleate for both tissue types. Linoleate lamb had greater (P < 0.0001) PUFA than Oleate lamb in muscle and adipose tissue. Conjugated linoleic acids (CLA; cis-9, trans-11 and trans-10, cis-12) were greater (P < 0.0001) in muscle and adipose tissue of lambs fed safflower seeds. Lambs fed Linoleate had greater (P < 0.0001) CLA in adipose tissue and muscle than lambs fed Oleate. Saturated fatty acids were greater (P < 0.0001) in s.c. adipose tissue than in tailhead adipose tissue. Mono- and polyunsaturated fatty acids were greater (P < 0.0001) in tailhead adipose tissue than in s.c. adipose tissue. Weight percentages of 18:1(trans-11) ranked tailhead adipose tissue = KPH adipose tissue > s.c. adipose tissue and semitendinosus > longissimus, whereas CLA ranked tailhead adipose tissue > s.c. adipose tissue > KPH adipose tissue and semitendinosus > longissimus. Feeding mono- and polyunsaturated fatty acids increased tissue 18:1(trans-11) and CLA, which is a favorable change in regard to current human dietary guidelines.


Assuntos
Ácidos Graxos/análise , Ácido Linoleico/administração & dosagem , Ácido Oleico/administração & dosagem , Ovinos/crescimento & desenvolvimento , Tecido Adiposo/química , Ração Animal , Animais , Composição Corporal , Ácidos Graxos/química , Humanos , Carne/normas , Músculo Esquelético/química , Política Nutricional , Distribuição Aleatória , Sementes , Ovinos/metabolismo
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