155 research outputs found
Strain and slackness of achilles tendon during passive joint mobilization via imaging ultrasonography
Background: In vivo study of the mechanical behavior of tendons may bring advances in evaluating the impact of intervention programs for flexibility and strength, in clinical practice and sports. Objective: The aim of this study was to quantify the relative strain and slackness of achilles tendons during passive mobilization, for four ankle joint angles and two knee angles. Methods: The displacement of the muscle-tendon junction was quantified by means of ultrasound images acquired during passive ankle mobilization, with the aid of an electrogoniometer and an electromyograph to ensure the achievement of the required angles and muscle inactivity, respectively. Results: The strain values ranged from 4.28%±2.37 to -0.94%±1.58 for the fully extended knee, and from 2.38%±1.63 to -2.32%±2.16% for the flexed knee. Conclusions: The values found in this study confirm those in the literature and demonstrate how the Achilles tendon participates in length changes in the muscle-tendon unit during passive movement. These results suggest that the mechanical properties of tendinous tissues affect the relationship between the length of muscle fibers and the joint angle, even during this type of movement
Some extremal functions in Fourier analysis, III
We obtain the best approximation in , by entire functions of
exponential type, for a class of even functions that includes
, where , and , where . We also give periodic versions of these results where the
approximating functions are trigonometric polynomials of bounded degree.Comment: 26 pages. Submitte
Efectos del proceso de secado sobre la composición en ácidos grasos, perfil fenólico, tocoferoles y actividad antioxidante de almendras barú (Dipteryx alata Vog.)
This study carried out a chromatographic and spectrophotometric characterization of the bioactive compounds, antioxidants, phenolics, tocopherols, sterols and fatty acids of baru almonds “in natura” and submitted to drying processes. It was determined that baru “in natura” almonds presented high levels of phenolic compounds, vitamin C, antioxidants, phenolics, sterols, total monounsaturated fatty acids and low thrombogenic, and atherogenic indexes. During the process of drying it at 65 °C for 30 minutes, a decrease was noted in the levels of caffeic acid, chlorogenic acid, anthocyanins, p-coumaric acid, ferulic acid, o-coumaric acid, quercetin, and polyunsaturated fatty acids. The same condition resulted in an increase in the levels of gallic acid, rutin, catechin, trans-cinnamic acid, vanillin, m-coumaric acid, tocopherols, monounsaturated fatty acids and antioxidant activity (ORAC and DPPH). When submitted to a temperature of 105 ºC for 30 minutes the same behavior was seen with a reduction in the vitamin C and ORAC contents and increased presence of flavonoids.Este estudio realizó una caracterización cromatográfica y espectrofotométrica de la presencia de compuestos bioactivos, antioxidantes, fenólicos, tocoferoles, esteroles y ácidos grasos en almendras del tipo baru “in natura” y sometidos a procesos de secado. Se detectó, en la almendra de baru “in natura”, altos contenidos de compuestos fenólicos, vitamina C, antioxidantes fenólicos, esteroles, ácidos grasos monoinsaturados totales y bajos índices de trombogénicos y aterogénicos. Durante el proceso de secado a 65 °C durante 30 minutos, se observó una disminución en los niveles de ácido cafeíco, ácido clorogénico, antocianinas, ácido p-cumárico, ácido ferúlico, ácido o-cumárico, quercetina y ácidos grasos poliinsaturados. De la misma manera se observó un aumento en los niveles de ácido gálico, rutina, catequina, ácido trans-cinámico, vanilina, ácido m-cumárico, tocoferoles, ácidos grasos monoinsaturados y actividad antioxidante (ORAC y DPPH). Cuando se sometió a una temperatura de 105 °C durante 30 minutos, presentó el mismo comportamiento, sin embargo, influyó en la reducción del contenido de vitamina C y ORAC y aumentó la presencia de flavonoides
Superconducting Coherence and the Helicity Modulus in Vortex Line Models
We show how commonly used models for vortex lines in three dimensional
superconductors can be modified to include k=0 excitations. We construct a
formula for the k=0 helicity modulus in terms of fluctuations in the projected
area of vortex loops. This gives a convenient criterion for the presence of
superconducting coherence. We also present Monte Carlo simulations of a
continuum vortex line model for the melting of the Abrikosov vortex lattice in
pure YBCO.Comment: 4 pages RevTeX, 2 eps figures included using eps
Universal corrections to the Fermi-liquid theory
We show that the singularities in the dynamical bosonic response functions of
a generic 2D Fermi liquid give rise to universal, non-analytic corrections to
the Fermi-liquid theory. These corrections yield a term in the specific
heat, terms in the effective mass and the uniform spin susceptibility
, and term in . The existence of these
terms has been the subject of recent controversy, which is resolved in this
paper. We present exact expressions for all non-analytic terms to second order
in a generic interaction and show that only U(0) and matter.Comment: references added, a typo correcte
IKKβ targeting reduces KRAS-induced lung cancer angiogenesis in vitro and in vivo: A potential anti-angiogenic therapeutic target
Objectives: The ability of tumor cells to drive angiogenesis is an important cancer hallmark that positively correlates with metastatic potential and poor prognosis. Therefore, targeting angiogenesis is a rational therapeutic approach and dissecting proangiogenic pathways is important, particularly for malignancies driven by oncogenic KRAS, which are widespread and lack effective targeted therapies. Based on published studies showing that oncogenic RAS promotes angiogenesis by upregulating the proangiogenic NF-κB target genes IL-8 and VEGF, that NF-κB activation by KRAS requires the IKKβ kinase, and that targeting IKKβ reduces KRAS-induced lung tumor growth in vivo, but has limited effects on cell growth in vitro, we hypothesized that IKKβ targeting would reduce lung tumor growth by inhibiting KRAS-induced angiogenesis. Materials and methods: To test this hypothesis, we targeted IKKβ in KRAS-mutant lung cancer cell lines either by siRNA-mediated transfection or by treatment with Compound A (CmpdA), a highly specific IKKβ inhibitor, and used in vitro and in vivo assays to evaluate angiogenesis. Results and conclusions: Both pharmacological and siRNA-mediated IKKβ targeting in lung cells reduced expression and secretion of NF-κB-regulated proangiogenic factors IL-8 and VEGF. Moreover, conditioned media from IKKβ-targeted lung cells reduced human umbilical vein endothelial cell (HUVEC) migration, invasion and tube formation in vitro. Furthermore, siRNA-mediated IKKβ inhibition reduced xenograft tumor growth and vascularity in vivo. Finally, IKKβ inhibition also affects endothelial cell function in a cancer-independent manner, as IKKβ inhibition reduced pathological retinal angiogenesis in a mouse model of oxygen-induced retinopathy. Taken together, these results provide a novel mechanistic understanding of how the IKKβ pathway affects human lung tumorigenesis, indicating that IKKβ promotes KRAS-induced angiogenesis both by cancer cell-intrinsic and cancer cell-independent mechanisms, which strongly suggests IKKβ inhibition as a promising antiangiogenic approach to be explored for KRAS-induced lung cancer therapy
Towards a quantum universe
In this short review we study the state of the art of the great problems in
cosmology and their interrelationships. The reconciliation of these problems
passes undoubtedly through the idea of a quantum universe.Comment: 7 pages, Accepted for publication in Astrophysics & Space Scienc
Fósforo da biomassa microbiana e atividade de fosfatases ácidas durante a diminuição do fósforo disponível no solo
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