494 research outputs found

    Kinetic-growth self-avoiding walks on small-world networks

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    Kinetically-grown self-avoiding walks have been studied on Watts-Strogatz small-world networks, rewired from a two-dimensional square lattice. The maximum length L of this kind of walks is limited in regular lattices by an attrition effect, which gives finite values for its mean value . For random networks, this mean attrition length scales as a power of the network size, and diverges in the thermodynamic limit (large system size N). For small-world networks, we find a behavior that interpolates between those corresponding to regular lattices and randon networks, for rewiring probability p ranging from 0 to 1. For p < 1, the mean self-intersection and attrition length of kinetically-grown walks are finite. For p = 1, grows with system size as N^{1/2}, diverging in the thermodynamic limit. In this limit and close to p = 1, the mean attrition length diverges as (1-p)^{-4}. Results of approximate probabilistic calculations agree well with those derived from numerical simulations.Comment: 10 pages, 7 figure

    Microstructure and precipitation behavior of advanced RAFM steels for high-temperature applications on fusion reactors

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    The composition of new eigth 9% Cr reduced activation ferritic/martensitioc steels (RAFMs) has been finely tuned in order to increase the amount of fine MX precipitates and reduce coarse M23_{23}C6_{6} carbides through the application of thermomechanical treatments. The microstructural investigations by TEM/STEM and EELS have shown M23_{23}C6_{6}, M2_{2}X (Cr2_{2}N), and MX (Ta, V, and Ti-rich) precipitates after tempering at 750 °C/2 h. Higher N contens (0.04–0.03 wt%) seems to favored M2_{2}X precipitation over MX with V contents round 0.2 wt%. MX-Ti rich presents sizes larger than MX (Ta or V rich). EELS anlysis have shown that the MX (Ta, V and Ti rich) precipitated after tempering at 750 °C/2 h are mainly carbo-nitrides. Composition, size, number density and carbon and nitrogen content on MX and M2_{2}X is discussed in terms of the composition of each Alloy

    Cost-effectiveness of two dry needling interventions for plantar heel pain: A secondary analysis of an rct

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    Plantar heel pain is a common cause of foot pain that affects patients’ quality of life and represents a significant cost for the healthcare system. Dry needling and percutaneous needle electrolysis are two minimally invasive treatments that were shown to be effective for the management of plantar heel pain. The aim of our study was to compare these two treatments in terms of health and economic consequences based on the results of a published randomized controlled trial. For this, we evaluated the costs from the point of view of the hospital and we carried out a cost-effectiveness study using quality of life as the main variable according to the Eq-5D-5L questionnaire. The cost of the complete treatment with dry needling (DN) was €178.86, while the percutaneous needle electrolysis (PNE) was €200.90. The quality of life of patients improved and was translated into +0.615 quality-adjusted life years (QALYs) for DN and +0.669 for PNE. PNE presented an average incremental cost-effectiveness ratio (ICER) of €411.34/QALY against DN. These results indicate that PNE had a better cost-effectiveness ratio for the treatment of plantar heel pain than DN

    Cost-effectiveness of upper extremity dry needling in the rehabilitation of patients with stroke

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    Introduction: Dry needling (DN) has been shown to be effective for the treatment of upper extremity hypertonia in patients with stroke. Purpose: To evaluate the cost-effectiveness of DN in patients with stroke. Methods: A cost-effectiveness analysis was performed in a research study conducted at a Spanish public hospital where patients were classified into two groups with or without DN. Hypertonia was measured using the Modified Modified Ashworth Scale (MMAS), and quality of life (QOL) was assessed using the EuroQoL 5-dimension questionnaire. Data regarding the effects and costs of physiotherapy were presented by calculating the mean and 95% confidence interval. The health outcomes were evaluated considering the rate of responders to the treatment based on the MMAS. Spanish preference weights were used to estimate quality-adjusted life years (QALYs). The incremental cost-effectiveness ratio (ICER) and incremental cost-utility ratio (ICUR) were calculated to determine the economic value of DN. Results: Eighty patients with stroke in the subacute stage of recovery were selected to participate in this study. Based on the rate of responders, the ICER of the DN group was very low. Despite the sensitivity analysis performed, the results of the ICUR were not encouraging. Discussion: Cost-effectiveness with responder rate results were favourable for the DN group and were confirmed by the sensitivity analysis according to levels of care. In addition, our findings revealed that 4 weeks of treatment could be more cost-effective than 8 weeks. DN treatment of the upper extremity appears to be cost-effective based on the rate of responders measured using the MMAS scale. © The Author(s) 2021

    Comparing two dry needling interventions for plantar heel pain: a randomised controlled trial

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    OBJECTIVES: To compare the effectiveness of dry needling (DN) versus percutaneous needle electrolysis (PNE) for improving the level of pain, function and quality of life (QoL) of patients suffering from plantar heel pain (PHP) provoked by myofascial trigger points. DESIGN: A prospective, parallel-group, randomised controlled trial with blinded outcome assessment. SETTING: A single treatment facility in the State of Kuwait. PARTICIPANTS: 118 participants were screened for eligibility. Of these, 102 participants were enrolled (30 men (49.5±8.9 years) and 72 women (48.1±8.8 years)) and 68 of them completed the trial. INTERVENTIONS: Two parallel groups, one study arm received DN and a stretching protocol whereas the other arm received percutaneous needling electrolysis with a stretching protocol. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome measure was the Foot Pain domain of the Foot Health Status Questionnaire, with 13 questions related to foot health-related domains. Secondary outcome measures included the 0-10 numerical rating scale pain visual analogue scale (VAS) scores, performed before and after each treatment session. In addition, QoL was measured using the EuroQoL-5 dimensions. All measurements were taken at baseline, at 4, 8, 12, 26 and 52 weeks. RESULTS: Foot Pain domain improved at all time points for DN group (p<0.001; 29.7 (17.8 to 41.5)) and percutaneous needling electrolysis group (p<0.001; 32.7 (18.3 to 47.0)), without significant differences between groups. Pain VAS scores decreased at all time points for both DN (p<0.001; -2.6 (-4.0 to -1.2)) and percutaneous needling electrolysis group (p<0.001; -3.0 (-4.5 to -1.6)). QoL improved at 4 weeks for both DN (p<0.01; 0.15 (0.5 to 0.25)) and percutaneous needling electrolysis group (p<0.01; 0.09 (0.01 to 0.17)) and at 8 and 52 weeks for the PNE group (p<0.01; 0.10 (0.02 to 0.18)), with significant differences between groups for the QoL at 52 weeks (p<0.05; 0.10 (0.01 to 0.18)). There were two small haematomas in the PNE group and one in the DN group. No serious adverse events were reported. CONCLUSIONS: Both PNE and DN were effective for PHP management, reducing mean and maximum pain since the first treatment session, with long lasting effects (52 weeks) and significant differences between groups in the case of QoL at 52 weeks in favour of the PNE group

    Reaction pathways and textural aspects of the replacement of anhydrite by calcite at 25 °C

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    The replacement of sulfate minerals by calcium carbonate polymorphs (carbonation) has important implications in various geological processes occurring in Earth surface environments. In this paper we report the results of an experimental study of the interaction between anhydrite (100), (010), and (001) surfaces and Na₂CO₃ aqueous solutions under ambient conditions. Carbonation progress was monitored by glancing incidence X-ray diffraction (GIXRD) and scanning electron microscopy (SEM). We show that the reaction progresses through the dissolution of anhydrite and the simultaneous growth of calcite. The growth of calcite occurs oriented on the three anhydrite cleavage surfaces and its formation is accompanied by minor vaterite. The progress of the carbonation always occurs from the outer-ward to the inner-ward surfaces and its rate depends on the anhydrite surface considered, with the (001) surface being much more reactive than the (010) and (100) surfaces. The thickness of the formed carbonate layer grows linearly with time. The original external shape of the anhydrite crystals and their surface details (e.g., cleavage steps) are preserved during the carbonation reaction. Textural characteristics of the transformed regions, such as the gradation in the size of calcite crystals, from ~2 μm in the outer region to ~17 μm at the calcite-anhydrite interface, the local preservation of calcite crystalographic orientation with respect to anhydrite and the distribution of the microporosity mainly within the carbonate layer without development of any significant gap at the calcite-anhydrite interface. Finally, we compare these results on anhydrite carbonation with those on gypsum carbonation and can explain the differences on the basis of four parameters: (1) the molar volume change involved in the replacement process in each case, (2) the lack/existence of epitactic growth between parent and product phases, (3) the kinetics of dissolution of the different surfaces, and (4) the chemical composition (amount of structural water) of the parent phases

    Dolores óseos y debilidad en miembros inferiores

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    Multiple myeloma oligosecretory constitutes 1% of all cases of multiple myeloma and more than 10% of hema- tological malignancies. It is characterized by clonal progression of malignant plasma cells in the bone marrow microenvironment that secrete a monoclonal protein in blood or urine, associated with organ dysfunction.El mieloma múltiple oligosecretor constituye el 1% de todos los casos de mieloma múltiple y más del 10% de las neoplasias hematológicas. Se caracteriza por la progresión clonal de células plasmáticas malignas en el microambiente de la médula ósea, que segregan una proteína monoclonal en sangre u orina, asociada a disfunción orgánica

    Self-avoiding walks and connective constants in small-world networks

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    Long-distance characteristics of small-world networks have been studied by means of self-avoiding walks (SAW's). We consider networks generated by rewiring links in one- and two-dimensional regular lattices. The number of SAW's unu_n was obtained from numerical simulations as a function of the number of steps nn on the considered networks. The so-called connective constant, μ=limnun/un1\mu = \lim_{n \to \infty} u_n/u_{n-1}, which characterizes the long-distance behavior of the walks, increases continuously with disorder strength (or rewiring probability, pp). For small pp, one has a linear relation μ=μ0+ap\mu = \mu_0 + a p, μ0\mu_0 and aa being constants dependent on the underlying lattice. Close to p=1p = 1 one finds the behavior expected for random graphs. An analytical approach is given to account for the results derived from numerical simulations. Both methods yield results agreeing with each other for small pp, and differ for pp close to 1, because of the different connectivity distributions resulting in both cases.Comment: 7 pages, 5 figure

    Height difference between the vestibular and palatal walls and palatal width: a cone beam computed tomography approach

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    Background: The objective of this study was to measure two parameters involved in tri-dimensional implant plan‑ ning: the position of the buccal and palatal bone wall and the palatal thickness. Methods: Cone beam computed tomography (CBCT) images (Planmeca ProMax 3D) of 403 teeth (208 upper teeth and 195 lower teeth) were obtained from 49 patients referred to the Dental School of Seville from January to Decem‑ ber 2014. The height diference between the palatal and buccal walls was measured on the most coronal point of both walls. The thickness of the palatal wall was measured 2 mm from the most coronal point of the palatal wall. Results: The mean values in the maxilla were 1.7±0.9 mm for central and lateral incisors, 2.2±1.7 mm for canines, 1.6±0.9 mm for premolars and 1.9±1.5 mm for molars. In the lower jaw, the mean values were 1.3±0.8 mm for inci‑ sors, 1.7±1.2 mm for canines, 2.3±1.3 mm for premolars, and 2.6±1.7 mm for molars. In the upper jaw, more than 55% of maxillary teeth (excluding second premolars and molars) presented mean height diferences greater than 1 mm. In the mandible, more than 60% of incisors showed a buccal bone thickness of 1 mm from the apical to lingual aspect. All teeth except the second premolar presented a buccal wall located more than 1 mm more apically than the lingual bone wall. Conclusions: The buccal bone wall is located more apically (greater than 1 mm) than the palatal or lingual table in most of the cases assessed. The thickness of the palatal or lingual table is also less than 2 mm in the maxilla and man‑ dible, except in the upper canines and premolars and the lower molars
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