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1.
Eur Rev Med Pharmacol Sci ; 28(2): 542-555, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38305631

RESUMO

OBJECTIVE: Osteoporosis (OP) is closely associated with gut microbiota (GM), yet the nature of their causal relationship remains elusive. Therefore, this study aims to reverse causality between GM and OP by using population cohorts and two-sample MR (TSMR) analysis. MATERIALS AND METHODS: In this study, we conducted an extensive genome-wide association study (GWAS) using publicly accessible summary statistics data for GM and OP. Employing rigorous criteria (p < 1*e-5), we identified independent genetic loci that exhibited significant associations with GM relative abundances as instrumental variables (IVs). A causal evaluation was primarily carried out using the inverse variance-weighted (IVW) method, supplemented by additional analyses such as MR-Egger, weighted median, simple mode, and weighted mode. RESULTS: We unveiled that increased abundances of the family Pasteurellaceae, order Pasteurellales, and genus Ruminococcaceae UCG004 were linked to an increased risk of OP. Conversely, the family Oxalobacteraceae, unknown family id.1000006161, genus Lachnospiraceae NK4A136 group, unknown genus id.1000006162, and order NB1n were associated with a reduced risk of OP. To ensure the reliability of our findings, we conducted quality assessments through Cochrane's Q test and a leave-one-out analysis. Furthermore, the stability and consistency of the results were confirmed by the MR-Egger intercept test, Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) global test, and sensitivity analysis (p > 0.05). Our study reveals the causal relationships between 211 GM taxa and OP, pinpointing specific GM taxa associated with the risk of OP. This research sheds light on the genetic mechanisms that underlie GM-mediated OP and opens up promising avenues for identifying valuable biomarkers and potential therapeutic targets in future OP research. CONCLUSIONS: This study establishes a substantial GM-OP link with specific taxa being identified, offering biomarkers for early detection, tailored interventions, and improved patient education. These findings enhance OP diagnosis, prevention, and treatment, promising more effective, individualized care and inspiring future research.


Assuntos
Microbioma Gastrointestinal , Osteoporose , Humanos , Microbioma Gastrointestinal/genética , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Reprodutibilidade dos Testes , Osteoporose/genética , Biomarcadores
2.
Phys Rev E ; 102(5-1): 053307, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33327126

RESUMO

A lattice Boltzmann (LB) model is proposed to track the interface of binary fluid system based on the conservative-form Allen-Cahn (A-C) equation for phase field. Utilizing an equilibrium distribution function and a modified LB equation, this model is able to correctly recover the conservative A-C equation through the Chapman-Enskog analysis. A series of two-dimensional (2D) and three-dimensional (3D) phase-capturing benchmark tests have been conducted for validation, which include the diagonal translation of a circular interface, the rigid-body rotation of a Zalesak disk, and the deformation of 2D circular interface and 3D spherical interface in shear flows, all illustrating better accuracy and stability of the proposed model than the previous models tested. By coupling the incompressible hydrodynamic equation, a stationary droplet, a spinodal decomposition, and the Rayleigh-Taylor instability are simulated as well, showing the satisfying performance of the model in dealing with complex interfaces of binary fluid systems.

3.
Sci Rep ; 7(1): 5988, 2017 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-28729693

RESUMO

The charge-trapping memory devices with a structure Pt/Al2O3/(Ta2O5) x (TiO2) 1-x /Al2O3/p-Si (x = 0.9, 0.75, 0.5, 0.25) were fabricated by using rf-sputtering and atomic layer deposition techniques. A special band alignment between (Ta2O5) x (TiO2) 1-x and Si substrate was designed to enhance the memory performance by controlling the composition and dielectric constant of the charge-trapping layer and reducing the difference of the potentials at the bottom of the conduction band between (Ta2O5) x (TiO2) 1-x and Si substrate. The memory device with a composite charge storage layer (Ta2O5) 0.5 (TiO2) 0.5 shows a density of trapped charges 3.84 × 1013/cm2 at ± 12 V, a programming/erasing speed of 1 µs at ± 10 V, a 8% degradation of the memory window at ± 10 V after 104 programming/erasing cycles and a 32% losing of trapped charges after ten years. The difference among the activation energies of the trapped electrons in (Ta2O5) x (TiO2) 1-x CTM devices indicates that the retention characteristics are dominated by the difference of energy level for the trap sites in each TTO CTM device.

4.
Nat Mater ; 3(8): 529-32, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15258574

RESUMO

Metal oxides are emerging as important materials for their versatile properties such as high-temperature superconductivity, ferroelectricity, ferromagnetism, piezoelectricity and semiconductivity. Metal-oxide films are conventionally grown by physical and chemical vapour deposition. However, the high cost of necessary equipment and restriction of coatings on a relatively small area have limited their potential applications. Chemical-solution depositions such as sol-gel are more cost-effective, but many metal oxides cannot be deposited and the control of stoichiometry is not always possible owing to differences in chemical reactivity among the metals. Here we report a novel process to grow metal-oxide films in large areas at low cost using polymer-assisted deposition (PAD), where the polymer controls the viscosity and binds metal ions, resulting in a homogeneous distribution of metal precursors in the solution and the formation of uniform metal-organic films. The latter feature makes it possible to grow simple and complex crack-free epitaxial metal-oxides.


Assuntos
Cristalização/métodos , Teste de Materiais/métodos , Metalurgia/métodos , Nanotecnologia/métodos , Polímeros/química , Titânio/química , Adsorção , Cristalografia/métodos , Estudos de Viabilidade , Gases/química , Manufaturas , Membranas Artificiais , Metais/química , Conformação Molecular , Óxidos/química , Propriedades de Superfície
5.
Phytochemistry ; 47(5): 707-13, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9542166

RESUMO

The simulated structures of the enolases of Arabidopsis and the common ice plant contain a pair of Cys residues in the correct orientation to form a disulphide bond. Formation of this disulphide might be expected to affect the positioning of several residues in the active site. The enzyme in crude extracts of these two plants is activated by oxidation. Apparently formation of the disulphide crosslink enhances catalysis. The enolases from tomato leaves, maize roots and castor bean embryos lack one of these Cys residues and are not redox sensitive. It seems possible that enolase is redox-regulated by a cytosolic thioredoxin system in a limited number of plant species including ice plant and Arabidopsis.


Assuntos
Arabidopsis/enzimologia , Dissulfetos/química , Fosfopiruvato Hidratase/química , Proteínas de Plantas/química , Sequência de Aminoácidos , Sítios de Ligação , Dissulfetos/metabolismo , Ativação Enzimática , Dados de Sequência Molecular , Oxirredução , Fosfopiruvato Hidratase/metabolismo , Proteínas de Plantas/metabolismo , Plantas/enzimologia , Estrutura Terciária de Proteína , Homologia de Sequência de Aminoácidos
6.
Plant Physiol ; 115(3): 1201-9, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9390445

RESUMO

A cDNA fragment coding for the pea (Pisum sativum L.) chloroplastic glyceraldehyde-3-P dehydrogenase (EC 1.2.1.13) B-subunit and a truncated form corresponding in length to the A-subunit have been cloned into an expression vector, expressed in the absence of the A-subunit in a gap- Escherichia coli strain, purified, and studied. Like the isolated enzyme from higher plant chloroplasts, the recombinant enzymes have dual specificity for NADPH and NADH. The recombinant glyceraldehyde-3-P dehydrogenases have the same optimal pH as the enzyme isolated from pea chloroplasts. Like the native chloroplast enzyme, the recombinant B-subunit has a marked tendency to form large aggregates, whereas the truncated B-subunit exists as the tetramer. The recombinant B-subunit glyceraldehyde 3-P dehydrogenase is more sensitive to dithiothreitol than its truncated form. It seems likely that a different pair of cysteines is responsible for the redox sensitivity of the activity of the enzyme composed of B-subunits than the cysteine residues implicated in the modulation of the activity of the enzyme composed of A-subunits by previous work in this laboratory.


Assuntos
Cloroplastos/enzimologia , Gliceraldeído-3-Fosfato Desidrogenases/genética , Pisum sativum/enzimologia , Sequência de Aminoácidos , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Ativação Enzimática , Escherichia coli/genética , Gliceraldeído-3-Fosfato Desidrogenases/isolamento & purificação , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Dados de Sequência Molecular , NAD/metabolismo , NADP/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Especificidade da Espécie
7.
Plant J ; 10(3): 553-60, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8811868

RESUMO

In the stimulated three-dimensional structure of the Chlamydomonas reinhardtii sedoheptulose bisphosphatase (EC 3.1.3.37) there are two cysteine residues close enough to one another to form a redox-sensitive disulfide bond which would cross-link the nucleotide and carbon substrate domains. Examination of the redox modulation of this sedoheptulose bisphosphatase confirms that it resembles the higher plant enzyme in being activated by reduction. In the wheat and Arabidopsis enzymes, for which there is sequence information and which, like the Chlamydomonas enzyme, can be modeled, both redox-sensitive Cys residues appear to be located on the regulatory nucleotide-binding domain. Apparently different Cys residues are involved in modulation in the algal and higher plant sedoheptulose bisphosphatases.


Assuntos
Chlamydomonas reinhardtii/enzimologia , Dissulfetos/química , Monoéster Fosfórico Hidrolases/química , Sequência de Aminoácidos , Animais , Cisteína/química , Ditiotreitol/farmacologia , Ativação Enzimática , Frutose-Bifosfatase/química , Magnésio/farmacologia , Mercaptoetanol/farmacologia , Modelos Moleculares , Dados de Sequência Molecular , Oxirredução , Monoéster Fosfórico Hidrolases/metabolismo , Filogenia , Estrutura Terciária de Proteína , Substâncias Redutoras/farmacologia , Alinhamento de Sequência , Reagentes de Sulfidrila/farmacologia , Suínos
8.
Sov Med ; (11): 27-9, 1991.
Artigo em Russo | MEDLINE | ID: mdl-1767307

RESUMO

The paper presents the results of intracavitary chemotherapy with deposited cytostatics of advanced ovarian cancer as well experimental, morphological, biochemical and pharmacological data. Intraabdominal introduction of microspheres filled with cyclophosphamide, 5-fluorouracil, doxorubicin can be a variant of drug therapy in multimodality treatment of ovarian cancer. Combination of intracavitary chemotherapy with a systemic one has the advantage of local and regional effect which is not inhibited by mediated action of the deposited cytostatics via the systemic blood flow. The method is indicated in residual tumor dissemination after cytoreductive surgery and ovarian cancer with ascites.


Assuntos
Ciclofosfamida/administração & dosagem , Cistadenocarcinoma/tratamento farmacológico , Doxorrubicina/administração & dosagem , Fluoruracila/administração & dosagem , Microesferas , Neoplasias Ovarianas/tratamento farmacológico , Adulto , Celulose/análogos & derivados , Estudos de Avaliação como Assunto , Feminino , Humanos , Pessoa de Meia-Idade
9.
Eksp Onkol ; 10(1): 52-5, 1988.
Artigo em Russo | MEDLINE | ID: mdl-3371247

RESUMO

An increase of doxorubicin concentration in different organs and tissues and its decrease in the peripheral blood were observed when studying pharmacokinetics of this drug administered in the 10% solution of polyvinylpyrrolidone. A prolonged and stable release of carminomycin from glue composition MK-10-0 "carminacryl" confirms an expediency of alpha-cyanoacrylate use for deposition of anthracycline antibiotics with the aim of loco-regional chemotherapy.


Assuntos
Carrubicina/farmacocinética , Cianoacrilatos/administração & dosagem , Daunorrubicina/análogos & derivados , Doxorrubicina/farmacocinética , Povidona/administração & dosagem , Animais , Carrubicina/administração & dosagem , Doxorrubicina/administração & dosagem , Avaliação Pré-Clínica de Medicamentos , Injeções Intraperitoneais , Injeções Subcutâneas , Masculino , Veículos Farmacêuticos , Coelhos , Ratos , Ratos Endogâmicos
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