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1.
J Appl Microbiol ; 130(2): 450-463, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32544275

RESUMO

AIMS: Reproduction can induce maternal oxidative stress, and resveratrol is able to alleviate oxidative stress. This study aimed to investigate the protective effects of resveratrol supplementation in mice during pregnancy and lactation. METHODS AND RESULTS: Pregnant mice were randomly divided into three groups: (i) Pure water (Con); (ii) Cellulose sodium dissolves with 20 mg kg-1 resveratrol (R1) and (iii) Cellulose sodium dissolves with 40 mg kg-1 resveratrol (R2). The experiment starts at pregnancy and ends at weaning. The results showed that resveratrol increased mammary cell proliferation and the mRNA expressions of UDP glucuronosyltransferase family 1 member A1 (UGT1A1) and cytochrome P450 proteins (CYP1A1), while decreased superoxide dismutase, extracellular (SOD3) in the mammary gland. Further study showed that resveratrol promoted the mRNA expressions of genes involved in mitophagy, such as transcription factor Eß (Tfeß), Bcl1lc3ß, homosapiens microtubule-associated protein 1 light-chain 3 beta (Map1lc3ß), Parkin, sequestosome1 (p62), autophagy-related protein (Atg5) and Beclin-1 (Becn1) in the mammary gland. Moreover, resveratrol increased the abundances of some intestinal microbial species. 40 mg kg-1 resveratrol significantly increased the contents of Acidobacteri, unidentified acidbacteria, Bacilales, Staphylococcaceae and Staphylococcus at phylum, class, order, family and genus level respectively. CONCLUSION: Our results indicate that resveratrol supplementation may promote mammary cell proliferation and antioxidant ability through mitophagy and regulating gut microbiota in pregnant mice. SIGNIFICANCE AND IMPACT OF THE STUDY: Current study proved that resveratrol could affect mammary cell proliferation and antioxidation capacity during pregnancy and lactation in mice for the first time. The underlying mechanisms may be related to mitophagy and gut microbiota.


Assuntos
Antioxidantes/farmacologia , Proliferação de Células/efeitos dos fármacos , Lactação/efeitos dos fármacos , Glândulas Mamárias Animais/efeitos dos fármacos , Resveratrol/farmacologia , Animais , Antioxidantes/administração & dosagem , Feminino , Microbioma Gastrointestinal/efeitos dos fármacos , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/metabolismo , Camundongos , Mitofagia/efeitos dos fármacos , Mitofagia/genética , Gravidez , Resveratrol/administração & dosagem
2.
J Appl Microbiol ; 128(2): 574-583, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31562837

RESUMO

AIMS: Leucine supplementation promotes intestinal health, but the mechanism is largely unknown. This study aimed to elucidate the mechanisms underlying the beneficial effects of leucine on intestinal homeostasis. METHODS AND RESULTS: Female ICR mice (6-week-old) were randomly assigned into three groups: (i) mice received a basal diet; (ii) mice received a dietary 0·5% crystalline l-leucine supplementation; and (iii) mice received a dietary 1·0% crystalline l-leucine supplementation. Our results showed that leucine supplementation stimulated the secretion of SIgA in mice ileum and expression of cytokines related to SIgA production. Moreover, leucine supplementation improved the expression of mTOR and p70S6K1 expression. Further study showed that leucine supplementation markedly decreased microbiota richness and induced a shift in the Firmicutes : Bacteroidetes ratio in favour of Firmicutes. CONCLUSIONS: Therefore, our data suggested that leucine supplementation could enhance intestinal health through the regulation of mTOR pathway and promoting SIgA secretion in the mouse intestine, which might be associated with intestinal microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: The present study found that dietary leucine supplementation of mice could improve intestinal health by enhancing intestinal SIgA secretion via a nonexclusive mechanism, which might include T cell-dependent pathway, T cell-independent pathway and gut microbiota.


Assuntos
Imunoglobulina A Secretora/metabolismo , Mucosa Intestinal/metabolismo , Leucina/administração & dosagem , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Citocinas/metabolismo , Suplementos Nutricionais/análise , Feminino , Microbioma Gastrointestinal/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/microbiologia , Camundongos , Camundongos Endogâmicos ICR
3.
Eur Rev Med Pharmacol Sci ; 28(3): 899-906, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38375696

RESUMO

OBJECTIVE: The pathogenesis of Parkinson's disease (PD) is associated with abnormal iron accumulation. Magnetic resonance imaging (MRI) studies have shown that patients with Parkinson's disease have an increased amount of iron in their substantia nigra (SN). We have undertaken a meta-analysis of studies using MRI in PD, to explore the potential role of MRI in diagnosing PD using abnormal iron deposition in SN as a candidate biomarker. MATERIALS AND METHODS: Searches of PubMed, Embase, and Medline databases revealed 16 studies that compared PD patients and healthy controls (HC). A sensitivity analysis and subgroup analysis were performed to evaluate the reliability of our results. Estimates were pooled by the fixed-effects model. As an expression of I2, we computed the proportion of variation due to heterogeneity. RESULTS: We included 16 studies with sample sizes of 435 PD and 355 HC in our meta-analysis. Results showed that SN iron deposition was significantly elevated (p<0.00001) in patients with PD compared to HC ones (SMD=0.72, 95% confidence interval 0.57 to 0.87, p<0.00001). CONCLUSIONS: Our findings, based on a homogeneous group-level analysis, suggest that MRI-based SN iron deposition could be used to distinguish PD from HC. For a more rigorous investigation of SN iron deposition in PD, larger cohort studies are needed.


Assuntos
Doença de Parkinson , Humanos , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/metabolismo , Reprodutibilidade dos Testes , Substância Negra/diagnóstico por imagem , Substância Negra/metabolismo , Imageamento por Ressonância Magnética/métodos , Ferro/metabolismo
4.
Science ; 263(5153): 1590-3, 1994 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-17744787

RESUMO

Sound velocities in fluid and crystalline hydrogen were measured under pressure to 24 gigapascals by Brillouin spectroscopy in the diamond anvil cell. The results provide constraints on the intermolecular interactions of dense hydrogen and are used to construct an intermolecular potential consistent with all available data. Fluid perturbation theory calculations with the potential indicate that sound velocities in hydrogen at conditions of the molecular layer of the Jovian planets are lower than previously believed. Jovian models consistent with the present results remain discrepant with recent free oscillation spectra of the planet by 15 percent. The effect of changing interior temperatures, the metallic phase transition depth, and the fraction of high atomic number material on Jovian oscillation frequencies is also investigated with the Brillouin equation of state. The present data place strong constraints on sound velocities in the Jovian molecular layer and provide an improved basis for interpreting possible Jovian oscillations.

5.
Science ; 239(4844): 1131-4, 1988 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-17791973

RESUMO

The crystal structure and equation of state of solid hydrogen have been determined directly to 26.5 gigapascals at room temperature by new synchrotron x-ray diffraction techniques. Solid hydrogen remains in the hexagonal close-packed structure under these pressure-temperature conditions and exhibits increasing structural anisotropy with pressure. The pressure-volume curve determined from the x-ray data represents the most accurate experimental measurement of the equation of state to date in this pressure range. The results remove the discrepancy between earlier indirect determinations and provide a new experimental constraint on the molecular-to-atomic transition predicted at higher pressures.

6.
J Med Chem ; 42(9): 1537-45, 1999 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-10229624

RESUMO

Comparative molecular field analysis (CoMFA), a 3-D QSAR technique, is widely used to correlate biological activity with observed differences in steric and electrostatic fields. In this study, CoMFA was employed to generate a model, based upon 14 structurally diverse 5-phenylhydantoin analogues, to delineate structural and electrostatic features important for enhanced sodium channel binding. Correlation by partial least squares (PLS) analysis of in vitro sodium channel binding activity (expressed as log IC50) and the CoMFA descriptor column generated a final non-cross-validated model with R2 = 0.988 for the training set. The final CoMFA model explained the data better than a simpler correlation with log P (R2 = 0.801) for the same training set. The CoMFA steric and electrostatic maps described two general features that result in enhanced binding to the sodium channel. These include a preferred 5-phenyl ring orientation and a favorable steric effect resulting from the C5-alkyl chain. This model was then utilized to accurately predict literature sodium channel activities for hydantoins 14-20, which were not included in the training set. Finally the hydantoin CoMFA model was used to design the structurally novel alpha-hydroxy-alpha-phenylamide 21. Synthesis and subsequent sodium channel evaluation of compound 21 (predicted IC50 = 9 microM, actual IC50 = 9 microM), a good binder to the sodium channel, established that the intact hydantion ring is not necessary for efficient binding to this site. Thus alpha-hydroxy-alpha-phenylamides may represent a new class of ligands that bind with increased potency to the sodium channel.


Assuntos
Amidas/síntese química , Anticonvulsivantes/metabolismo , Hidantoínas/metabolismo , Neurônios/metabolismo , Canais de Sódio/metabolismo , Amidas/química , Amidas/farmacologia , Animais , Córtex Cerebral/metabolismo , Córtex Cerebral/ultraestrutura , Hidantoínas/química , Ativação do Canal Iônico , Análise dos Mínimos Quadrados , Ligantes , Modelos Moleculares , Conformação Molecular , Ratos , Relação Estrutura-Atividade , Sinaptossomos/metabolismo
7.
Zhonghua Fu Chan Ke Za Zhi ; 31(6): 345-7, 1996 Jun.
Artigo em Zh | MEDLINE | ID: mdl-9206168

RESUMO

OBJECTIVE: To evaluate the role of fetal cerebral and umbilical blood flow for predicting intrauterine fetal growth retardation (IUGR). METHODS: Doppler ultrasonography was used to study pulsatility indexes (PI) of the fetal middle cerebral artery (MCA) and umbilical artery (UA) in 84 normal late pregnancies and 31 IUGR cases. RESULTS: MCA PI were significantly lower in IUGR fetuses than that of normal fetuses (P < 0.01). UA PI and UA PI/MCA PI ratio were higher in IUGR group than that of normal group (P < 0.01). The sensitivities of MCA PI, UA PI and UA PI/MCA PI ratio for predicting IUGR were 80.64%, 70.96% and 87.09% respectively at the cut off level with 2 standard deviation (SD). The specificities were 94.05%, 88.90% and 97.61% respectively. CONCLUSIONS: Doppler ultrasonography for predicting IUGR was a practical and sensitive method.


Assuntos
Doenças Fetais/diagnóstico por imagem , Retardo do Crescimento Fetal/diagnóstico por imagem , Ultrassonografia Pré-Natal , Adulto , Velocidade do Fluxo Sanguíneo , Artérias Cerebrais/embriologia , Artérias Cerebrais/fisiopatologia , Feminino , Humanos , Gravidez , Ultrassonografia Doppler , Artérias Umbilicais/fisiopatologia
8.
J Phys Condens Matter ; 26(2): 026004, 2014 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-24334442

RESUMO

In this study, we have deposited an 57Fe sensor layer at the upper interface, i.e. the interface between the oxide barrier and the upper electrode in selected magnetic tunnel junctions (MTJs), in order to perform nuclear resonant scattering with the aim of obtaining direct information on the magnetic properties and quality of this interface. This is a unique approach as it makes use of this powerful technique to give information at the atomic level, and specifically from the interface where the sensor layer is deposited. By varying sample tunnel barrier thicknesses and oxidation times in the preparation of this barrier, we have observed that longer oxidation time results in not only an increase of the magnetic hyperfine fields, but also causes an interesting crystallization and smoothing of the interface. We also observed that boron atoms diffuse away from the lower part of the upper FeCoB electrode toward the capping layer. An important observation, which has a crucial effect in tunnel magnetoresistance values, is the absence of any magnetically dead FeO layer at the interface. Another finding is that the deposition of Fe on MgO is much smoother than the deposition of MgO on Fe.

9.
J Phys Condens Matter ; 25(13): 135302, 2013 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-23470360

RESUMO

Lower interfaces in magnetic tunnel junctions (MTJs), which are the basic components in many spintronic devices such as magnetoresistive random access memories, have crucial effects on the performance of these devices. To obtain more insight into such interfaces, we have introduced an ultrathin sensor layer of (57)Fe at the interface between the lower electrode and the oxide barrier in selected MTJs. This allowed us to perform nuclear resonant scattering measurements, which provide direct information on the magnetic properties and quality of the interfaces. The application of nuclear resonant scattering to study interfaces in MTJs is a unique approach in the sense that it gives information at the atomic level, and specifically from the interface where the sensor layer is deposited. Samples with different tunnel barrier thicknesses and varied oxidation times in the preparation of this barrier have been studied. These show that oxidation can not only increase the magnetic hyperfine fields but also cause an interesting smoothing and crystallizing of the interface. Another interesting finding is the observation of boron diffusion into the lower part of the FeCoB lower electrode towards the Ta seed layer.

10.
11.
Bull Environ Contam Toxicol ; 79(5): 524-8, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17924049

RESUMO

The organochlorine insecticide aldrin is commonly used in intensive agriculture, and demonstrates estrogenic activity. Rotifers such as Brachionus calyciflorus are favored test animals in aquatic toxicology because of their more sensitivity to most toxicants. In the tested concentration range of 0.04-1.28 mg/L, aldrin shortened significantly the durations of embryonic development. Lower concentrations of aldrin had an intriguing effect on the reproduction of the rotifers and are beneficial to their survival. Different endpoints of both development and reproduction had different sensitivity to aldrin. The reproductive endpoint of the rotifers is more sensitive to aldrin than the developmental endpoint.


Assuntos
Aldrina/toxicidade , Inseticidas/toxicidade , Rotíferos/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Longevidade , Reprodução/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade
12.
Nat Mater ; 4(12): 922-7, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16284620

RESUMO

Nanometre-sized inorganic dots, wires and belts have a wide range of electrical and optical properties, and variable mechanical stability and phase-transition mechanisms that show a sensitive dependency on size, shape and structure. The optical properties of the semiconductor ZnS in wurtzite structures are considerably enhanced, but the lack of structural stability limits technological applications. Here, we demonstrate that morphology-tuned wurtzite ZnS nanobelts show a particular low-energy surface structure dominated by the +/-[210] surface facets. Experiments and calculations show that the morphology of ZnS nanobelts leads to a very high mechanical stability to approximately 6.8 GPa, and also results in an explosive mechanism for the wurtzite-to-sphalerite phase transformation together with in situ fracture of the nanobelts. ZnS wurtzite nanobelts provide a model that is useful not only for understanding the morphology-tuned stability and transformation mechanism, but also for improving synthesis of metastable nanobelts with quantum effects for electronic and optical devices.


Assuntos
Nanoestruturas/química , Nanotecnologia , Sulfetos/química , Compostos de Zinco/química , Pressão Atmosférica , Nanoestruturas/ultraestrutura , Teoria Quântica , Semicondutores , Espectrometria por Raios X , Propriedades de Superfície , Termodinâmica , Difração de Raios X
13.
Proc Natl Acad Sci U S A ; 97(25): 13494-9, 2000 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-11095719

RESUMO

We have studied the elasticity and pressure-density equation of state of MgO in diamond cells to 55 GPa and have doubled the previous pressure limit of accurate elasticity determinations for crystals. Integrating single-crystal velocity data from Brillouin scattering measurements and density data from polycrystalline x-ray diffraction, we obtained the three principal elastic tensor elements (C(11), C(12), and C(44)) and various secondary elasticity parameters, including single-crystal elastic anisotropy, Cauchy relation, aggregate sound velocities, and Poisson's ratio, as functions of pressure. The present study also provides a direct determination of pressure without recourse to any prior pressure standard, thus creating a primary pressure scale. The commonly used ruby fluorescence pressure scale has thus been improved to 1% accuracy by the new MgO scale.

14.
Biophys J ; 85(5): 3202-13, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14581220

RESUMO

Quasilongitudinal sound velocities and the second-order elastic moduli of tetragonal hen egg-white lysozyme crystals were determined as a function of relative humidity (RH) by Brillouin scattering. In hydrated crystals the measured sound velocities in the [110] plane vary between 2.12 +/- 0.03 km/s along the [001] direction and 2.31 +/- 0.08 km/s along the [110] direction. Dehydration from 98% to 67% RH increases the sound velocities and decreases the velocity anisotropy in (110) from 8.2% to 2.0%. A discontinuity in velocity and an inversion of the anisotropy is observed with increasing dehydration providing support for the existence of a structural transition below 88% RH. Brillouin linewidths can be described by a mechanical model in which the phonon is coupled to a relaxation mode of hydration water with a single relaxation time of 55 +/- 5 ps. At equilibrium hydration (98% RH) the longitudinal moduli C(11) + C(12) + 2C(66) = 12.81 +/- 0.08 GPa, C(11) = 5.49 +/- 0.03 GPa, and C(33) = 5.48 +/- 0.05 GPa were directly determined. Inversion of the measured sound velocities in the [110] plane constrains the combination C(44) + (1/2)C(13) to 2.99 +/- 0.05 GPa. Further constraints on the elastic tensor are obtained by combining the Brillouin quasilongitudinal results with axial compressibilities determined from high-pressure x-ray diffraction. We constrain the adiabatic bulk modulus to the range 2.7-5.3 GPa.


Assuntos
Cristalografia/métodos , Interferometria/métodos , Muramidase/química , Análise Espectral/métodos , Água/química , Acústica , Anisotropia , Proteínas do Ovo/química , Elasticidade , Umidade , Substâncias Macromoleculares , Conformação Proteica , Estresse Mecânico
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