488 research outputs found
Worldwide Incidence and Surgical Costs of Tendon Injuries: A Systematic Review and Meta-Analysis
3d printing and testing of rose thorns or limpet teeth inspired anchor device for tendon tissue repair
Purposes: Advancements in medical technology have enabled medical specialists to resolve significant problems concerning tendon
injuries. However, despite the latest improvements, surgical tendon repair remains challenging. This study aimed to explore the capabilities of the current state-of-the-art technologies for implantable devices. Methods: After performing extensive patent landscaping and
literature review, an anchored tissue fixation device was deemed the most suitable candidate. This design was firstly investigated numerically, realizing a Finite Element Model of the device anchored to two swine tendons stumps, to simulate its application on a severed
tendon. Two different hook designs, both bio-inspired, were tested while retaining the same device geometry and anchoring strategy.
Then, the applicability of a 3D-printed prototype was tested on swine tendons. Finally, the device-tendon stumps ensemble was subjected
to uniaxial tensile tests. Results: The results show that the investigated device enables a better load distribution during the immobilized
limb period in comparison to standard suture-based approaches, yet it still presents several design flaws. Conclusions: The current implantable solutions do not ensure an optimal result in terms of strength recovery. This and other weak points of the currently available
proposals will serve as a starting point for future works on bio-inspired implantable devices for tendon repair
Nutrição e alimentação de peixes.
Introdução. Hábitos alimentares. Rações para peixes. Alimentação. Exigências nutricionais. Outros componentes da dieta. Ingredientes para a formulação de dietas para peixes. Armazenamento de rações e ingredientes secos. Índices de desempenho e eficiência alimentar
Canonical Analysis of the Jackiw-Teitelboim Model in the Temporal Gauge. I. The Classical Theory
As a preparation for its quantization in the loop formalism, the
2-dimensional gravitation model of Jackiw and Teitelboim is analysed in the
classical canonical formalism. The dynamics is of pure constraints as it is
well-known. A partial gauge fixing of the temporal type being performed, the
resulting second class constraints are sorted out and the corresponding Dirac
bracket algebra is worked out. Dirac observables of this classical theory are
then calculated.Comment: 15 pages, Latex. Misprint correction
Discrete embedded solitons
We address the existence and properties of discrete embedded solitons (ESs),
i.e., localized waves existing inside the phonon band in a nonlinear
dynamical-lattice model. The model describes a one-dimensional array of optical
waveguides with both the quadratic (second-harmonic generation) and cubic
nonlinearities. A rich family of ESs was previously known in the continuum
limit of the model. First, a simple motivating problem is considered, in which
the cubic nonlinearity acts in a single waveguide. An explicit solution is
constructed asymptotically in the large-wavenumber limit. The general problem
is then shown to be equivalent to the existence of a homoclinic orbit in a
four-dimensional reversible map. From properties of such maps, it is shown that
(unlike ordinary gap solitons), discrete ESs have the same codimension as their
continuum counterparts. A specific numerical method is developed to compute
homoclinic solutions of the map, that are symmetric under a specific reversing
transformation. Existence is then studied in the full parameter space of the
problem. Numerical results agree with the asymptotic results in the appropriate
limit and suggest that the discrete ESs may be semi-stable as in the continuous
case.Comment: A revtex4 text file and 51 eps figure files. To appear in
Nonlinearit
Long time black hole evaporation with bounded Hawking flux
The long time behavior of an evaporating Schwarzschild black hole is studied
exploiting that it can be described by an effective theory in 2D, a particular
dilaton gravity model.
A crucial technical ingredient is Izawa's result on consistent deformations
of 2D BF theory, while the most relevant physical assumption is boundedness of
the asymptotic matter flux during the whole evaporation process.
An attractor solution, the endpoint of the evaporation process, is found. Its
metric is flat. However, the behavior of the dilaton field is nontrivial: it is
argued that during the final flicker a first order phase transition occurs from
a linear to a constant dilaton vacuum, thereby emitting a shock wave with a
total energy of a fraction of the Planck mass. Another fraction of the Planck
mass may reside in a cold remnant. [Note: More detailed abstract in the paper]Comment: 34 pages, 6 figures, v2: included new references and 2 new footnotes;
v3: mayor revisions (extended intro, included pedagogical example, rearranged
presentation, extended discussion on information paradox, updated
references); v4: updated refs. (+ new ones), added comments, mostly on
dilaton evaporation, rewrote abstract (short for arXiv, long for journal),
moved pedagogic sec. to ap
Comprehensive evaluation of the pharmacological and toxicological effects of γ-valerolactone as compared to γ-hydroxybutyric acid: Insights from in vivo and in silico models
Γ-valerolactone (GVL), marketed online as "Tranquilli-G" and "excellent Valium", is used as a legal substitute for γ-hydroxybutyric acid (GHB); however, until now, GVL has only been connected to one Drug-Facilitated Sexual Assault (DFSA) case. Moreover, the pharmaco-toxicological effects of GVL are poorly studied. The aim of this study was to investigate the 1) in vivo effects of gavage administration of GVL (100-3000 mg/kg) on neurological (myoclonia, convulsions), sensorimotor (visual, acoustic, and overall tactile) responses, righting reflex, thermoregulation, motor activity (bar, drag, and accelerod test) and cardiorespiratory changes (heart rate, breath rate, oxygen saturation, and pulse distension) in CD-1 male mice and the 2) in silico ADMET profile of GVL in comparison to GHB and the open active form γ-hydroxyvaleric acid (GHV). The present study demonstrates that GVL inhibits, in a dose-dependent manner, sensorimotor and motor responses and induces cardiorespiratory depression (at a dose of 3000 mg/kg) in mice. The determination of the ED50 in sensorimotor and motor responses revealed that GVL is about 4-5 times less potent than GHB. In silico prediction of ADMET profiles revealed toxicokinetic similarities between GHB and GHV, and differences with GVL. These results suggest that GVL could be used as a substitute for GHB and should be added to forensic toxicology screenings
Influência da embalagem e do período de armazenamento no teor residual de SO2 em banana passa
No presente trabalho foram determinados os teores residuais de SO2 em passas elaboradas com bananas tratadas com solução de metabisulfito de potássio a 2%, acondicionadas em alumínio,, celofane, polietileno e alumínio+polietileno ("combinado") e armazenadas de 15 a 105 dias à temperatura ambiente. A determinação de SO2 foi realizada com medida potenciométrica em eletrodo com separação de ar (em sistema de fluxo contínuo). Constatou-se que: a) o produto perde SO2 após processamento; b) o celofane proporciona, relativamente aos demais materiais testados, uma maior retenção de anidrido sulfuroso nas passas; c) os teores de SO2 encontrados nas passas de banana desde os 15 dias até os 105 dias de armazenamento não ultrapassam o limite estabelecido pela Comissão Nacional de Normas e Padrões para Alimentos.In the present work residual SO2 in banana figs was determined after treatment with 2% potassium metabisulfite solution, packaging in aluminum foil, cellophane, polyetylene film or aluminum foil+polyetylene and stores from 15 to 105 days at room temperature. It is concluded that: a) the product loses SO2 after processing; b) the cellophane a continuous flow system. It is concluded that: a) the product loses SO2 after processing; b) the cellophane retains more SO2 in the banana figs, than aluminum foil or polyetylene film; c) the amounts of SO2 found in the banana figs at any time after 15 days of storage were below the limit established by the CNNPA (National Commission for Food Standards and Regulations)
Crescimento da tambatinga de 1,5 a 130 gramas de peso vivo em pisciculturas familiares na região de Divinópolis (TO).
O desenvolvimento da piscicultura familiar na região dos municípios de Divinópolis e Abreulândia, no estado do Tocantins, foi observado como uma oportunidade de compreender o processo produtivo e identificar demandas tecnológicas de produções familiares da região, a fim de subsidiar ações de pesquisa que possam colaborar com o desenvolvimento da atividade. Nesse sentido, oito unidades produtivas de peixe estão sendo monitoradas quanto à qualidade de água e índices de desempenho zootécnico. O presente trabalho apresenta os dados de crescimento da tambatinga referentes a três meses de cultivo em viveiros escavados de 200 a 800 m2
IDEST: International Database of Emotional Short Texts
We introduce a database (IDEST) of 250 short stories rated for valence, arousal, and comprehensibility in two languages. The texts, with a narrative structure telling a story in the first person and controlled for length, were originally written in six different languages (Finnish, French, German, Portuguese, Spanish, and Turkish), and rated for arousal, valence, and comprehensibility in the original language. The stories were translated into English, and the same ratings for the English translations were collected via an internet survey tool (N = 573). In addition to the rating data, we also report readability indexes for the original and English texts. The texts have been categorized into different story types based on their emotional arc. The texts score high on comprehensibility and represent a wide range of emotional valence and arousal levels. The comparative analysis of the ratings of the original texts and English translations showed that valence ratings were very similar across languages, whereas correlations between the two pairs of language versions for arousal and comprehensibility were modest. Comprehensibility ratings correlated with only some of the readability indexes. The database is published in osf.io/9tga3, and it is freely available for academic research.</p
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