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Identifying indicators of non-functional overreaching during periods of increased training volume and/or intensity is particularly relevant for understanding the detrimental impacts incurred, as well as how these factors contribute to heightened injury risks among exposed athletes. This study aimed to compare the effects of a congested training period versus a standard training period on the strength levels and landing forces of female young aerobic gymnastics athletes. A prospective cohort study design was implemented, spanning four weeks. Fifty athletes (aged 16.2 ± 1.1 years old) at a trained/developmental level, competing at the regional level, were observed throughout the study. During two of these weeks (specifically weeks 2 and 3), half of the group was subjected to a congested training period consisting of six sessions per week (HTF), while the other half continued with their regular four sessions per week (STF). During each week of observation, participants underwent evaluation using the countermovement jump test (CMJ), squat jump test (SJ), and the leg land and hold test (LHT), with measurements taken on a force platform. The main outcomes repeatedly observed over the four weeks were CMJ peak landing force, CMJ peak power, SJ peak power, SJ maximum negative displacement, LHT time to stabilization, and LHT peak drop landing force. Significant interactions (time*group) were observed in CMJ peak power (p < 0.001), CMJ peak landing force (p < 0.001), SJ peak power (p < 0.001), SJ maximum negative displacement (p < 0.001), LHT time to stabilization (p < 0.001), and LHT peak drop landing force (p < 0.001). Furthermore, the results of the final assessment revealed significantly lower CMJ peak power (p = 0.008) and SJ peak power (p = 0.002) in the HTF group compared to the STF group. Additionally, significantly higher values of CMJ peak landing force (p = 0.041), SJ maximum negative displacement (p = 0.015), and LHT peak drop landing force (p = 0.047) were observed in the HTF group compared to the STF group. In conclusion, the increase in training frequency over two weeks significantly contributed to declines in neuromuscular power performance and peak landing forces. This indicates that intensified training periods may acutely expose athletes not only to performance drops but also to an increased risk of injury due to reduced capacity to absorb landing forces.
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Central venous catheter (CVC) insertion is a routine procedure in the management of critically ill patients. We report a clinical case of inadvertent placement of an internal jugular vein CVC into the right pleural cavity, despite employing clinical and imaging-based techniques to ensure proper catheter positioning. Infusion of fluids and vasopressors through this misplaced catheter led to hypertensive pleural effusion and subsequent cardiorespiratory arrest. Return of spontaneous circulation was achieved after two cycles of cardiopulmonary resuscitation. While multiple imaging modalities are recommended for confirming appropriate CVC placement, each method has inherent limitations. This case highlights the imperative need for a high index of suspicion to avert such complications and pretends to review some of each method's limitations.
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Orthotic devices play an important role in medical treatment, addressing various pathologies and promoting patient recovery. Customization of orthoses to fit individual patient morphologies and needs is essential for optimal functionality and patient comfort. The advent of additive manufacturing has revolutionized the biomedical field, offering advantages such as cost reduction, increased personalization, and enhanced dimensional adaptability for orthotics manufacturing. This research focuses on the impact strength of nine polymeric materials printed by additive manufacturing, including an evaluation of the materials' performance under varying conditions comprising different printing directions (vertical and horizontal) and exposure to artificial sweat for different durations (0 days, 24 days, and 189 days). The results showed that Nylon 12 is good for short-term (24 days) immersion, with absorbed energies of 78 J and 64 J for the vertical and horizontal directions, whereas Polycarbonate (PC) is good for long-term immersion (189 days), with absorbed energies of 66 J and 78 J for the vertical and horizontal directions. Overall, the findings contribute to a better understanding of the suitability of these materials for biomedical applications, considering both short-term and long-term exposure to physiological and environmental conditions.
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The study presented herein concerns the mechanical properties of two common polymers for potential biomedical applications, PLA and PETG, processed through fused filament fabrication (FFF)-Material Extrusion (ME). For the uniaxial tension tests carried out, two printing orientations-XY (Horizontal, H) and YZ (Vertical, V)-were considered according to the general principles for part positioning, coordinates, and orientation typically used in additive manufacturing (AM). In addition, six specimens were tested for each printing orientation and material, providing insights into mechanical properties such as Tensile Strength, Young's Modulus, and Ultimate Strain, suggesting the materials' potential for biomedical applications. The experimental results were then compared with correspondent mechanical properties obtained from the literature for other polymers like ASA, PC, PP, ULTEM 9085, Copolyester, and Nylon. Thereafter, fatigue resistance curves (S-N curves) for PLA and PETG, printed along 45°, were determined at room temperature for a load ratio, R, of 0.2. Scanning electron microscope observations revealed fibre arrangements, compression/adhesion between layers, and fracture zones, shedding light on the failure mechanisms involved in the fatigue crack propagation of such materials and giving design reference values for future applications. In addition, fractographic analyses of the fatigue fracture surfaces were carried out, as well as X-ray Computed Tomography (XCT) and Thermogravimetric (TGA)/Differential Scanning Calorimetric (DSC) tests.
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BACKGROUND: Sleep disorders are common among patients admitted to intensive care units (ICUs). This study aimed to assess the perceptions of sleep quality, anxiety, depression, and stress reported by ICU patients and the relationships between these perceptions and patient variables. METHODS: This cross-sectional study used consecutive non-probabilistic sampling to select participants. All patients admitted for more than 72 hours of ICU hospitalization at a Portuguese hospital between March and June 2020 were asked to complete the "Richard Campbell Sleep Questionnaire" and "Anxiety, depression, and Stress Assessment Questionnaire." The resulting data were analyzed using descriptive statistics, Pearson's correlation coefficient, Student t-tests for independent samples, and analysis of variance. The significance level for rejecting the null hypothesis was set to α ≤0.05. RESULTS: A total of 52 patients admitted to the ICU for at least 72 hours was recruited. The mean age of the participants was 64 years (standard deviation, 14.6); 32 (61.5%) of the participants were male. Approximately 19% had psychiatric disorders. The prevalence of self-reported poor sleep was higher in women (t[50]=2,147, P=0.037) and in participants with psychiatric problems, although this difference was not statistically significant (t[50]=-0.777, P=0.441). Those who reported having sleep disorders before hospitalization had a worse perception of their sleep. CONCLUSIONS: Sleep quality perception was worse in female ICU patients, those with psychiatric disorders, and those with sleep alterations before hospitalization. Implementing early interventions and designing nonpharmacological techniques to improve sleep quality of ICU patients is essential.
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The aim of this study was to compare the effects of jumping interval training (JIT) and running high-intensity interval training (HIIT) on the aerobic, anaerobic and jumping performances of youth female aerobic gymnasts. A randomized controlled study was conducted over an 8-week period, involving 73 youth female athletes (16.2 ± 1.3 years old) of aerobic gymnastics. The study comprised two experimental groups (JIT and HIIT) and a control group. Participants in the experimental groups engaged in two additional training sessions per week alongside their regular training regimen, while the control group followed their usual training routine. Before and after the intervention period, gymnasts were assessed for their performance in the countermovement jump test (CMJ), the specific aerobic gymnastics anaerobic test (SAGAT) and the 20-m multistage fitness test. Significant interactions time × group were found in SAGAT (p < 0.001; = 0.495), CMJ (p < 0.001; = 0.338) and 20-m multistage fitness test (p < 0.001; = 0.500). The time × group analysis post-intervention revealed significantly lower scores in SAGAT for the control group compared to the JIT (p = 0.003) and HIIT (p = 0.034). Additionally, significantly higher scores were observed for the JIT group in the CMJ test compared to the HIIT (p = 0.020) and control (p = 0.028) groups following the intervention. Finally, the 20 m multistage fitness test post-intervention revealed significantly lower scores for the control group compared to JIT (p < 0.001) and HIIT (p < 0.001). Both JIT and HIIT are recommended training strategies to adopt in aerobic gymnastics for significantly improving the aerobic and anaerobic performances of athletes. However, JIT may be particularly relevant to use as it offers additional benefits in improving vertical jumping performances.
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Rendimiento Atlético , Gimnasia , Entrenamiento de Intervalos de Alta Intensidad , Humanos , Femenino , Gimnasia/fisiología , Entrenamiento de Intervalos de Alta Intensidad/métodos , Rendimiento Atlético/fisiología , Adolescente , Prueba de Esfuerzo , Ejercicio Pliométrico/métodos , Carrera/fisiologíaRESUMEN
The low-pressure die casting (LPDC) process was experimentally and numerically studied to produce AlSi7Mg0.3 components such as steering knuckles. Steering knuckles are important safety components in the context of a vehicle's suspension system, serving as the mechanical interface that facilitates the articulation of the steering to control the front wheel's orientation, while simultaneously bearing the vertical load imposed by the vehicle's weight. This work focuses on the development of a numerical model in ProCAST®, replicating the production of the aforementioned part. The model analyses parameters such as the filling dynamics, solidification process, and presence of shrinkage porosities. For the purpose of evaluating the quality of the castings, six parts were produced and characterised, both mechanically (tensile and hardness tests) and microstructurally (porosity and optical microscopy analysis). When correlating simulation results with the available experimental data, it is possible to conclude that the usage of the LPDC process is a viable alternative to the use of steels and other metals for the production of very high-quality castings while using lighter alloys such as aluminium and magnesium in more demanding applications.
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This study examined relationships among players' physical characteristics, match external loads, and heart rate recovery (HRR) during match substitutions in a congested fixture of an overseas futsal training camp. Eleven under-20 national futsal players' anthropometric characteristics (age, body height, body mass, % fat, and % muscle) and physical fitness [HRmax, VO2max, maximal aerobic speed (MAS) during the 30-15 intermittent fitness test (IFT)] were determined. Additionally, locomotion profiles during field play and HRR sitting on the bench were recorded during five matches. A repeated-measures analysis of variance and Pearson's correlation coefficient were used for statistical analysis. The results revealed that the overall observed correlations among anthropometry, body composition, physical fitness, and HRR were inconsistent across all the matches and substitutions. However, the numbers of moderate (1.00-1.99 m/s2), moderate-to-high (2.00-2.99 m/s2), and high (3.00-50.00 m/s2) intensities of acceleration presented negative correlations in the last match (r < -0.76; p < 0.05). HRR during match substitutions may have been influenced by uncontrolled factors across all the match play and recovery. HRR measures may be affected mainly by fatigue caused by the accumulation of accelerations throughout a congested fixture during a congested-schedule of a futsal training camp.
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BACKGROUND: Inherited retinal diseases (IRDs) are a group of rare degenerative disorders of the retina that can lead to blindness from birth to late middle age. Knowing the target population and its resources is essential to better plan support measures. The aim of this study was to evaluate the socioeconomic characteristics of regions in Portugal where IRD patients reside to inform the planning of vision aid and rehabilitation intervention measures. RESULTS: This study included 1082 patients from 973 families, aged 3 to 92 years, with a mean age of 44.8 ± 18.1 years. Patients living with an IRD were identified in 190 of the 308 municipalities. According to this study, the estimated IRD prevalence in Portugal was 10.4 per 100,000 inhabitants, and by municipalities, it ranged from 0 to 131.2 per 100,000 inhabitants. Overall, regions with a higher prevalence of IRD have a lower population density (r=-0.371, p < 0.001), a higher illiteracy rate (r = 0.404, p < 0.001) and an overall older population (r = 0.475, p < 0.001). Additionally, there is a lower proportion of doctor per capita (r = 0.350, p < 0.001), higher social security pensions beneficiaries (r = 0.439, p < 0.001), worse water quality for human consumption (r=-0.194, p = 0.008), fewer audiences at the cinema (r=-0.315, p < 0.001) and lower proportion of foreign guests in tourist accommodations (r=-0.287, p < 0.001). CONCLUSION: The number of identified patients with IRD varied between regions. Using data from national statistics (PORDATA), we observed differences in socioeconomic characteristics between regions. Multiple targeted aid strategies can be developed to ensure that all IRD patients are granted full clinical and socioeconomic support.
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Enfermedades de la Retina , Persona de Mediana Edad , Humanos , Adulto , Portugal/epidemiología , Enfermedades de la Retina/epidemiología , Retina , Factores SocioeconómicosRESUMEN
BACKGROUND: Ankle-foot orthoses (AFOs) are vital in gait rehabilitation for patients with stroke. However, many conventional AFO designs may not offer the required precision for optimized patient outcomes. With the advent of 3D scanning and printing technology, there is potential for more individualized AFO solutions, aiming to enhance the rehabilitative process. OBJECTIVE: This nonrandomized trial seeks to introduce and validate a novel system for AFO design tailored to patients with stroke. By leveraging the capabilities of 3D scanning and bespoke software solutions, the aim is to produce orthoses that might surpass conventional designs in terms of biomechanical effectiveness and patient satisfaction. METHODS: A distinctive 3D scanner, complemented by specialized software, will be developed to accurately capture the biomechanical data of leg movements during gait in patients with stroke. The acquired data will subsequently guide the creation of patient-specific AFO designs. These personalized orthoses will be provided to participants, and their efficacy will be compared with traditional AFO models. The qualitative dimensions of this experience will be evaluated using the Quebec User Evaluation of Satisfaction With Assistive Technology (QUEST) assessment tool. Feedback from health care professionals and the participants will be considered throughout the trial to ensure a rounded understanding of the system's implications. RESULTS: Spatial-temporal parameters will be statistically compared using paired t tests to determine significant differences between walking with the personalized orthosis, the existing orthosis, and barefoot conditions. Significant differences will be identified based on P values, with P<.05 indicating statistical significance. The Statistical Parametric Mapping method will be applied to graphically compare kinematic and kinetic data across the entire gait cycle. QUEST responses will undergo statistical analysis to evaluate patient satisfaction, with scores ranging from 1 (not satisfied) to 5 (very satisfied). Satisfaction scores will be presented as mean and SD values. Significant variations in satisfaction levels between the personalized and existing orthosis will be assessed using a Wilcoxon signed rank test. The anticipation is that the AFOs crafted through this innovative system will either match or outperform existing orthoses in use, with higher patient satisfaction rates. CONCLUSIONS: Embracing the synergy of technology and biomechanics may hold the key to revolutionizing orthotic design, with the potential to set new standards in patient-centered orthotic solutions. However, as with all innovations, a balanced approach, considering both the technological possibilities and individual patient needs, will be paramount to achieving optimal outcomes. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/52365.
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Wolcott-Rallison Syndrome (WRS) is the most common cause of permanent neonatal diabetes mellitus among consanguineous families. The diabetes associated with WRS is non-autoimmune, insulin-requiring and associated with skeletal dysplasia and growth retardation. The therapeutic options for WRS patients rely on permanent insulin pumping or on invasive transplants of liver and pancreas. WRS has a well identified genetic cause: loss-of-function mutations in the gene coding for an endoplasmic reticulum kinase named PERK (protein kinase R-like ER kinase). Currently, WRS research is facilitated by cellular and rodent models with PERK ablation. While these models have unique strengths, cellular models incompletely replicate the organ/system-level complexity of WRS, and rodents have limited scalability for efficiently screening potential therapeutics. To address these challenges, we developed a new in vivo model of WRS by pharmacologically inhibiting PERK in zebrafish. This small vertebrate displays high fecundity, rapid development of organ systems and is amenable to highly efficient in vivo drug testing. PERK inhibition in zebrafish produced typical WRS phenotypes such as glucose dysregulation, skeletal defects, and impaired development. PERK inhibition in zebrafish also produced broad-spectrum WRS phenotypes such as impaired neuromuscular function, compromised cardiac function and muscular integrity. These results show that zebrafish holds potential as a versatile model to study WRS mechanisms and contribute to the identification of promising therapeutic options for WRS.
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In recent years, the stacking and twisting of atom-thin structures with matching crystal symmetry has provided a unique way to create new superlattice structures in which new properties emerge1,2. In parallel, control over the temporal characteristics of strong light fields has allowed researchers to manipulate coherent electron transport in such atom-thin structures on sublaser-cycle timescales3,4. Here we demonstrate a tailored light-wave-driven analogue to twisted layer stacking. Tailoring the spatial symmetry of the light waveform to that of the lattice of a hexagonal boron nitride monolayer and then twisting this waveform result in optical control of time-reversal symmetry breaking5 and the realization of the topological Haldane model6 in a laser-dressed two-dimensional insulating crystal. Further, the parameters of the effective Haldane-type Hamiltonian can be controlled by rotating the light waveform, thus enabling ultrafast switching between band structure configurations and allowing unprecedented control over the magnitude, location and curvature of the bandgap. This results in an asymmetric population between complementary quantum valleys that leads to a measurable valley Hall current7, which can be detected by optical harmonic polarimetry. The universality and robustness of our scheme paves the way to valley-selective bandgap engineering on the fly and unlocks the possibility of creating few-femtosecond switches with quantum degrees of freedom.
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The valley degree of freedom1-4 of electrons in materials promises routes towards energy-efficient information storage with enticing prospects for quantum information processing5-7. Current challenges in utilizing valley polarization are symmetry conditions that require monolayer structures8,9 or specific material engineering10-13, non-resonant optical control to avoid energy dissipation and the ability to switch valley polarization at optical speed. We demonstrate all-optical and non-resonant control over valley polarization using bulk MoS2, a centrosymmetric material without Berry curvature at the valleys. Our universal method utilizes spin angular momentum-shaped trefoil optical control pulses14,15 to switch the material's electronic topology and induce valley polarization by transiently breaking time and space inversion symmetry16 through a simple phase rotation. We confirm valley polarization through the transient generation of the second harmonic of a non-collinear optical probe pulse, depending on the trefoil phase rotation. The investigation shows that direct optical control over the valley degree of freedom is not limited to monolayer structures. Indeed, such control is possible for systems with an arbitrary number of layers and for bulk materials. Non-resonant valley control is universal and, at optical speeds, unlocks the possibility of engineering efficient multimaterial valleytronic devices operating on quantum coherent timescales.
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The purpose of this study was three-fold: (i) to compare total distance, high-speed running (HSR) distance, and sprint distance covered per 5-minute epoch by players acting as both starters and substitutes; (ii) to compare the locomotor demands between the moments the players entered the match (45-60, 60-75 and 75-90 minutes); and (iii) to compare the locomotor demands of the players between the variations of the within- and between-playing positions. Twenty-one male professional soccer players competing in the Professional Premier League of one of the European countries were observed over sixteen official matches. The players were monitored during all matches using a Global Navigation Satellite System. The measures collected were total distance (TD; m), distance in HSR, sprint distance, HSR, and sprint counts. Considering the comparisons between the splits over the second half of match play, a significant difference between the starters and the substitutes was observed only for sprint distance in the 90-95 minute split (Z = -2.023; p = 0.043). Moreover, no substantial differences were found between the moment the substitute player entered the match regarding total distance (H = 2.650; p = 0.266), HSR distance (H = 1.738; p = 0.419), and sprint distance (H = 0.048; p = 0.976). However, the comparison of between-playing positions revealed considerable differences in total distance (H = 29.246; p < 0.001), and HSR distance (H = 12.153; p = 0.002) covered by the players acting as starters. In contrast, for substitute players, such differences were reported in HSR distance (H = 27.892; p < 0.001) and sprint distance (H = 15.879; p < 0.001). In conclusion, this study suggests that acting as a starter or a substitute does not significantly affect the intensity of effort except during the last periods of match play. However, the contextual factor of performing in a specific playing position plays a significant role both for starters and substitutes.
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This descriptive study aimed to investigate the current practices of Portuguese and Brazilian soccer coaches in the design and implementation of small-sided games (SSGs) in soccer. A total of 187 male coaches participated in the online survey, consisting of 82 Portuguese and 105 Brazilian individuals. These coaches held various positions within the technical staff, with 63 serving as head coaches, 38 as assistant coaches, 38 as physical trainers, and 48 in other roles related to the technical staff. Additionally, the participants represented both youth (n = 102) and adult competitive levels (n = 59), along with some who were not currently associated with a specific group. The survey consisted of 32 questions divided into three main sections: (i) the timing of SSG application, (ii) the methods used for applying SSGs, and (iii) the reasons for applying SSGs. The Chi-square test revealed a statistically significant association between nationality and the frequency of SSGs used in training sessions during the pre-season (p = 0.039) and in-season (p < 0.001). Moreover, significant association between nationality and the time allocated to employing SSGs for targeting aerobic training (p < 0.001) was found. There was a significant association between nationality and the weekly frequency of SSGs use for targeting sprint training (p = 0.019). The Chi-square test identified significant associations between nationality and the use of SSGs for targeting technical training (p = 0.002), as well as for tactical training (p = 0.002). In summary, this study underscores that SSGs are primarily employed to enhance aerobic fitness, change of direction, technical skills, and tactical behaviors. Coaches generally favor employing SSGs two to three times a week, with typical sessions lasting between 16 to 30 minutes. Notably, the major discrepancies between nationalities lie in the importance assigned to the use of SSGs. However, in practice, the formats and objectives for implementing SSGs remain relatively similar.
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Purpose: This study aimed to: (i) analyze the changes in physical fitness and body composition following a 4-month intervention of small-sided games (SSG) training; and (ii) analyze the association between internal and external training loads and the observed changes in physical fitness and body composition among sedentary young adults. Methods: Sixty sedentary individuals (males: 30; females: 30) participated in this randomized controlled trial study. Physical fitness and body composition parameters were assessed at the 1st, 8th weeks, and 16th weeks after a SSG intervention. Results: Significant main effects of time and gender on overall physical fitness parameters, with a notable time-group interaction were observed. For body composition measures, we found significant main effects of time, group, and gender. Furthermore, we identified significant correlations between shuttle run, handgrip, and vertical jump performance, and the time spent at VO2max (TVO2max) during SSG (r = -0.779, p = 0.001; r = -0.788, p = 0.001; r = 0.692, p = 0.004, respectively). Handgrip strength exhibited significant correlations with heat exhaustion (HE) and total distance (TD) during SSG (r = -0.616, p = 0.014; r = -0.629, p = 0.012). Similarly, we observed significant correlations between hip perimeter (HP), skinfolds (SF), waist-to-hip ratio (W:H), and TVO2max (r = 0.624, p = 0.013; r = 0.663, p = 0.007; r = 0.535, p = 0.040, respectively). Conclusion: This study indicates that the intensity achieved during SSG plays a crucial role in fostering positive adaptations in aerobic capacity, maximal strength, and jumping performance in recreational soccer. Therefore, practitioners should ensure that SSG formats generate the required stimulus to sustain prolonged periods within VO2max zones.
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When a limb suffers a fracture, rupture, or dislocation, it is traditionally immobilized with plaster. This may induce discomfort in the patient, as well as excessive itching and sweating, which creates the growth of bacteria, leading to an unhygienic environment and difficulty in keeping the injury clean during treatment. Furthermore, if the plaster remains for a long period, it may cause lesions in the joints and ligaments. To overcome all of these disadvantages, orthoses have emerged as important medical devices to help patients in rehabilitation, as well as for self-care of deficiencies in clinics and daily life. Traditionally, these devices are produced manually, which is a time-consuming and error-prone method. From another point of view, it is possible to use imageology (X-ray or computed tomography) to scan the human body; a process that may help orthoses manufacturing but which induces radiation to the patient. To overcome this great disadvantage, several types of 3D scanners, without any kind of radiation, have emerged. This article describes the use of various types of scanners capable of digitizing the human body to produce custom orthoses. Studies have shown that photogrammetry is the most used and most suitable 3D scanner for the acquisition of the human body in 3D. With this evolution of technology, it is possible to decrease the scanning time and it will be possible to introduce this technology into clinical environment.
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Fracturas Óseas , Aparatos Ortopédicos , Humanos , Tomografía Computarizada por Rayos X , Tecnología , ExtremidadesRESUMEN
The primary objective of this study was to systematically investigate the physiological and physical fitness adaptations resulting from small-sided games (SSGs) training programs in basketball players competing at youth competitive levels, as compared to other training approaches and/or control groups. To achieve this, we conducted a literature search on PubMed, Scopus, SPORTDiscus, and Web of Science, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. From the initial 626 studies retrieved, five were considered eligible for the current study. Among the five included articles, four conducted comparisons between the effects of SSGs and running-based high-intensity interval training. Regarding this, the four studies revealed a significant improvement in the final velocity during the 30-15 Intermittent Fitness Test, ranging from 4.07% to 7.29% following SSG-based interventions. This improvement was not significantly different from the comparator group. Additionally, two studies indicated that the SSGs group showed a significant advantage in change-of-direction time, with improvements ranging from -2.11% to 6.69% after interventions, and these results were not significantly different from the comparator group. However, the effects on repeated sprint ability yielded contradictory findings; two studies reported significant improvements ranging from -5.00% to -2.16%, while two others did not show significant effects following SSGs-based interventions. Similarly, in the linear sprint, the results of SSGs-based interventions were inconsistent. In summary, based on the available research, it can be concluded that SSG-based training is effective in significantly enhancing aerobic performance and change of direction, comparable to alternative approaches. However, the effects on repeated sprint ability and sprint performance are not consistently demonstrated.
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Baloncesto , Acondicionamiento Físico Humano , Adolescente , Humanos , Baloncesto/fisiología , Ejercicio Físico , Adaptación FisiológicaRESUMEN
Objective: To reduce liver and lung dose during right breast irradiation while maintaining optimal dose to the target volume. This dose reduction has the potential to decrease acute side effects and long-term toxicity. Materials and Methods: 16 patients treated with radiation therapy for localized carcinoma of the right breast were included retrospectively. For the planning CT, each patient was immobilised on an indexed board with the arms placed above the head. CT scans were acquired in free-breathing (FB) as well as with deep inspiration breath hold (DIBH). Both scans were acquired with the same length. Planning target volumes (PTV's) were created with a 5 mm margin from the respective clinical target volumes (CTV's) on both CT datasets. The liver was outlined as scanned. Dose metrics evaluated were as follows: differences in PTV coverage, dose to the liver (max, mean, V90%, V50%, V30%), dose to lung (mean, V20Gy, relative electron density) and dose to heart (Dmax). The p-values were calculated using Wilcoxon signed-rank tests. A p-value was significant when <0.05. Results: Differences in PTV coverage between plans using FB and DIBH were less than 2 %. Maximum liver dose was significantly less using DIBH: 17.5 Gy versus FB: 40.3 Gy (p < 0.001). The volume of the liver receiving 10 % of the dose was significantly less using DIBH with 1.88 cm3 versus 72.2 cm3 under FB (p < 0.001). The absolute volume receiving 20 Gy in the right lung was larger using DIBH: 291 cm3 versus 230 cm3 under FB (p < 0.001) and the relative volume of lung receiving dose greater than 20 Gy was smaller with DIBH: 11.5 % versus 14 % in FB (p = 0.007). The relative electron density of lung was significantly less with DIBH: 0.59 versus 0.62 with FB, (p < 0.001). This suggests that the lung receives less dose due to its lower density when using DIBH. Conclusion: Radiation of the right breast using DIBH spares liver and lung tissue significantly and thus carries the potential of best practice for right sided breast cancer.
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Ever since its discovery1, the notion of the Berry phase has permeated all branches of physics and plays an important part in a variety of quantum phenomena2. However, so far all its realizations have been based on a continuous evolution of the quantum state, following a cyclic path. Here we introduce and demonstrate a conceptually new manifestation of the Berry phase in light-driven crystals, in which the electronic wavefunction accumulates a geometric phase during a discrete evolution between different bands, while preserving the coherence of the process. We experimentally reveal this phase by using a strong laser field to engineer an internal interferometer, induced during less than one cycle of the driving field, which maps the phase onto the emission of higher-order harmonics. Our work provides an opportunity for the study of geometric phases, leading to a variety of observations in light-driven topological phenomena and attosecond solid-state physics.