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Among the stimuli able to prevent early decreases in bone mineralization, exercise has a noticeable role per se as the source of mechanical stimulus or through lean tissue enlargement by its increasing of tensional stimulus. However, prevention strategies, including exercise, generally do not establish the moment in life when attention should begin to be paid to bone integrity, according to age group- and sex-related differences. Thus, this study analyzed the relationship between variables from the diagnosis of total and regional body composition, muscle strength, and bone mineral content (BMC) of femurs in young adult males. Thirty-four young Caucasian men (24.9 ± 8.6 years) had their body composition and bone density assessed by dual X-ray absorptiometry. The subjects performed a one-repetition maximum test (1-RM) in a bench press, front pulley, seated-row, push press, arm curl, triceps pulley, leg flexion, leg extension, and 45° leg press for the assessment of muscle strength in upper and lower limbs in single- and multi-joint exercises. Lean tissue mass in the trunk and upper and lower limbs were related to femoral BMC (Pearson coefficient ranging from 0.55 to 0.72, p < 0.01), and 1-RM values for different exercises involving both upper and lower limbs also correlated with femoral BMC (Pearson coefficients ranging from 0.34 to 0.46, p < 0.05). Taken together, these correlations suggest that muscle mass and strength are positively linked with the magnitude of femoral mass in men, even in early adulthood. Hence, the importance of an enhanced muscle mass and strength to the health of femoral bones in young adults was highlighted.
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Monoclonal antibodies have revolutionized the treatment of human diseases, which has made them the fastest-growing class of therapeutics, with global sales expected to reach $346.6 billion USD by 2028. Advances in antibody engineering and development have led to the creation of increasingly sophisticated antibody-based therapeutics (e.g. bispecific antibodies and chimeric antigen receptor T cells). However, approaches for antibody discovery have remained comparatively grounded in conventional yet reliable in vitro assays. Breakthrough developments in high-throughput single B-cell sequencing and immunoglobulin proteomic serology, however, have enabled the identification of high-affinity antibodies directly from endogenous B cells or circulating immunoglobulin produced in vivo. Moreover, advances in artificial intelligence offer vast potential for antibody discovery and design with large-scale repertoire datasets positioned as the optimal source of training data for such applications. We highlight advances and recent trends in how these technologies are being applied to antibody repertoire analysis.
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Anticorpos Biespecíficos , Proteômica , Humanos , Inteligência Artificial , Anticorpos MonoclonaisRESUMO
Incorrect limb position while lifting heavy weights might compromise athlete success during weightlifting performance, similar to the way that it increases the risk of muscle injuries during resistance exercises, regardless of the individual's level of experience. However, practitioners might not have the necessary background knowledge for self-supervision of limb position and adjustment of the lifting position when improper movement occurs. Therefore, the computerized analysis of movement patterns might assist people in detecting changes in limb position during exercises with different loads or enhance the analysis of an observer with expertise in weightlifting exercises. In this study, hidden Markov models (HMMs) were employed to automate the detection of joint position and barbell trajectory during back squat exercises. Ten volunteers performed three lift movements each with a 0, 50, and 75% load based on body weight. A smartphone was used to record the movements in the sagittal plane, providing information for the analysis of variance and identifying significant position changes by video analysis (p < 0.05). Data from individuals performing the same movements with no added weight load were used to train the HMMs to identify changes in the pattern. A comparison of HMMs and human experts revealed between 40% and 90% agreement, indicating the reliability of HMMs for identifying changes in the control of movements with added weight load. In addition, the results highlighted that HMMs can detect changes imperceptible to the human visual analysis.
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Treinamento Resistido , Humanos , Reprodutibilidade dos Testes , Treinamento Resistido/métodos , Levantamento de Peso/fisiologia , Postura , Extremidades , MovimentoRESUMO
Background: ABVD (doxorubicin, bleomycin, vinblastine, and dexamethasone) is a proven, curative regimen for Hodgkin lymphoma (HL). Prospective data describing HL treatment in sub-Saharan Africa are limited. We aimed to fill this knowledge gap, using data from Malawi. Methods: We report a prospective observational cohort of HL (aged ≥ 15) from a single, tertiary referral centre in Malawi. We enrolled patients with pathologicially confirmed Hodgkin lymphoma between June 1, 2013, and Dec 31, 2021 with follow-up censored on May 31, 2022. Patients were treated with ABVD and concurrent antiretroviral therapy if HIV-positive and were followed up for 5 years. The primary outcome was overall survival; secondary outcomes included progression-free survival, response assessment, and adverse events. Microcosting of HL diagnosis, treatment, and follow-up was embedded. Findings: We enrolled 38 patients with a median age of 27 years (interquartile range 19-46); eleven (28%) were HIV-positive. Of 35 patients treated with ABVD, 24 (71%) had stage III/IV, nine (26%) unfavourable limited stage, and two (6%) favourable limited stage. Among HIV-infected individuals, mean CD4 count at HL diagnosis was 179 cells/uL and ten (91%) had HIV RNA < 400 copies/mL. Grade 3/4 neutropenia occurred in 24 (68%) patients and caused treatment delay in 16 (46%). Of ten deaths, seven were due to HL, two possible treatment-related toxicity, and one uncertain. 2-year overall survival was 82% (95% CI 70-96%) and 2-year progression-free survival was 64% (95% CI 50-83%). PFS appeared better for HIV-positive patients (HR 0.23 (95% CI 0.05-1.02)) after controlling for stage and performance status (p = 0.05). We estimated $2708 (2022 USD) for HL diagnosis, treatment, and follow-up in our cohort. Interpretation: Our findings suggest that treatment with ABVD is safe, efficacious, and affordable for HL in Malawi. Outcomes are worse than in high-income countries due to HL progression. Future studies are needed to understand outcome inequities and to assess efficacy of therapies for patients with relapsed or refractory HL in Malawi. Funding: National Institutes of Health, Lineberger Comprehensive Cancer Center.
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Inquiries into properties of brain structure and function have progressed due to developments in magnetic resonance imaging (MRI). To sustain progress in investigating and quantifying neuroanatomical details in vivo, the reliability and validity of brain measurements are paramount. Quality control (QC) is a set of procedures for mitigating errors and ensuring the validity and reliability of brain measurements. Despite its importance, there is little guidance on best QC practices and reporting procedures. The study of hippocampal subfields in vivo is a critical case for QC because of their small size, inter-dependent boundary definitions, and common artifacts in the MRI data used for subfield measurements. We addressed this gap by surveying the broader scientific community studying hippocampal subfields on their views and approaches to QC. We received responses from 37 investigators spanning 10 countries, covering different career stages, and studying both healthy and pathological development and aging. In this sample, 81% of researchers considered QC to be very important or important, and 19% viewed it as fairly important. Despite this, only 46% of researchers reported on their QC processes in prior publications. In many instances, lack of reporting appeared due to ambiguous guidance on relevant details and guidance for reporting, rather than absence of QC. Here, we provide recommendations for correcting errors to maximize reliability and minimize bias. We also summarize threats to segmentation accuracy, review common QC methods, and make recommendations for best practices and reporting in publications. Implementing the recommended QC practices will collectively improve inferences to the larger population, as well as have implications for clinical practice and public health.
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This study sought to analyze the relationship between regional body composition, swimming performance, and aerobic and force profile determined through tethered swimming in well-trained swimmers. Eleven male and five female swimmers were involved in the study and underwent the following evaluations: (1) body composition, assessed by the dual-energy X-ray absorptiometry method (DXA); (2) swimming performance, determined for 200, 400, 800, and 1.500 m front-crawl swimming; (3) a tethered swimming force test to determine maximum and mean force (Fmax and Fmean); and (4) an incremental tethered swimming test for the aerobic profile determination of the swimmers. Oxygen uptake (VO2) was directly measured by an automatic and portable system (K4b2 Cosmed, Italy). The fat-free mass (lean mass + bone mineral content, LM+BMC) in lower and upper limbs (UL_LM+BMC: 6.74 ± 1.57 kg and LL_LM+BMC: 20.15 ± 3.84 kg) positively correlated with all indexes of aerobic conditioning level, showing higher coefficients to the indexes representing the ability to perform at high aerobic intensities (VO2max: 49.2 ± 5.9 mL·kg-1·min-1 and respiratory compensation point (RCP): 43.8 ± 6.0 mL·kg-1·min-1), which attained 0.82 and 0.81 (with VO2max), 0.81 and 0.80 (with RCP). The S200 (1.48 ± 0.13 m·s-1) was significantly correlated to Trunk_LM+BMC (r = 0.74), UL_LM+BMC (r = 0.72), Total_LM+BMC (r = 0.71), and LL_LM+BMC (r = 0.64). This study highlights that regional body composition plays an important role in swimming, and body segment analysis should be considered instead of the total body. Tethered swimming may represent a useful method for force and aerobic assessment, aiming at training control and performance enhancement.
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The current study analysed whether the osteogenic stimuli of exercises and sports have an independent effect on bone mineral density (BMD). Studies with a design having two different cohorts were searched and selected to distinguish the effect due to long-term involvement (i.e., athletes vs. non-active young with good bone health) and due to the planning of intervention (i.e., pre- vs. post-training) with exercises and sports. Moreover, only studies investigating the bone sites with a body-weight support function (i.e., lower limb, hip, and spine regions) were reviewed, since the osteogenic effects have incongruous results. A meta-analysis was performed following the recommendations of PRISMA. Heterogeneity (I2) was determined by combining Cochran's Q test with the Higgins test, with a significance level of α = 0.05. The studies reporting the effect of involvement in exercise and sports showed high heterogeneity for the lower limb, total hip, and spine (I2 = 90.200%, 93.334%, and 95.168%, respectively, with p < 0.01) and the effect size on sports modalities (Hedge's g = 1.529, 1.652, and 0.417, respectively, with p < 0.05) ranging from moderate to high. In turn, the studies reporting the effect of the intervention planning showed that there was no heterogeneity for the lower limb (I2 = 0.000%, p = 0.999) and spine (I2 = 77.863%, p = 0.000); however, for the hip, it was moderate (I2 = 49.432%, p = 0.054), with a low effect between the pre- and post-training moments presented only for the hip and spine (Hedge's g = 0.313 and 0.353, respectively, with p < 0.05). The current analysis supported the effect of involvement in exercise and sports by evidencing the effect of either weight-bearing or non-weight-bearing movements on BMD at the femoral, pelvic, and lumbar bones sites of the athletes when comparing to non-athletes or non-active peers with healthy bones. Moreover, the effect of different exercise and sports interventions highlighted the alterations in the BMD in the spine bone sites, mainly with long-term protocols (~12 months) planned with a stimulus with high muscle tension. Therefore, exercise and sport (mainly systematic long-term practice) have the potential to increase the BMD of bones with body-weight support beyond the healthy values reached during life phases of youth and adulthood.
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Perna (Membro) , Esportes , Adolescente , Humanos , Exercício Físico/fisiologia , Osso e Ossos , Densidade Óssea/fisiologia , Extremidade InferiorRESUMO
Purpose: This study aimed to evaluate the physiological responses associated with the stroke length (SL) and stroke rate (SR) changes as swimming velocity increases during an incremental step-test. Moreover, this study also aimed to verify if SL and SR relationships toward maximal oxygen uptake (VÌO2max), gas respiratory compensation point (RCP), exchange threshold (GET), and swimming cost can be applied to the management of endurance training and control aerobic pace. Methods: A total of 19 swimmers performed the incremental test until volitional exhaustion, with each stage being designed by percentages of the 400 m (%v400) maximal front crawl velocity. VÌO2max, GET, RCP, and the respective swimming velocities (v) were examined. Also, the stroke parameters, SL, SR, the corresponding slopes (SLslope and SRslope), and the crossing point (Cp) between them were determined. Results: GET and RCP corresponded to 70.6% and 82.4% of VÌO2max (4185.3 ± 686.1 mL min-1), and VÌO2 at Cp, SLslope, and SRslope were observed at 129.7%, 75.3%, and 61.7% of VÌO2max, respectively. The swimming cost from the expected VÌO2 at vSLslope (0.85 ± 0.18 kJ m-1), vSRslope (0.77 ± 0.17 kJ m-1), and vCp (1.09 ± 0.19 kJ m-1) showed correlations with GET (r = 0.73, 0.57, and 0.59, respectively), but only the cost at vSLslope and vCp correlated to RCP (0.62 and 0.69) and VÌO2max (0.70 and 0.79). Conclusion: SL and SR exhibited a distinctive pattern for the VÌO2 response as swimming velocity increased. Furthermore, the influence of SL on GET, RCP, and VÌO2max suggests that SLslope serves as the metabolic reference of heavy exercise intensity, beyond which the stroke profile defines an exercise zone with high cost, which is recommended for an anaerobic threshold and aerobic power training. In turn, the observed difference between VÌO2 at SRslope and GET suggests that the range of velocities between SL and SR slopes ensures an economical pace, which might be recommended to develop long-term endurance. The results also highlighted that the swimming intensity paced at Cp would impose a high anaerobic demand, as it is located above the maximal aerobic velocity. Therefore, SLslope and SRslope are suitable indexes of submaximal to maximal aerobic paces, while Cp's meaning still requires further evidence.
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This study aimed to apply an incremental tethered swimming test (ITT) with workloads (WL) based on individual rates of front crawl mean tethered force (Fmean) for the identification of the upper boundary of heavy exercise (by means of respiratory compensation point, RCP), and therefore to describe oxygen uptake kinetics (VO2k) and time limit (tLim) responses to WL corresponding to peak oxygen uptake (WLVO2peak). Sixteen swimmers of both sexes (17.6 ± 3.8 years old, 175.8 ± 9.2 cm, and 68.5 ± 10.6 kg) performed the ITT until exhaustion, attached to a weight-bearing pulley-rope system for the measurements of gas exchange threshold (GET), RCP, and VO2peak. The WL was increased by 5% from 30 to 70% of Fmean at every minute, with Fmean being measured by a load cell attached to the swimmers during an all-out 30 s front crawl bout. The pulmonary gas exchange was sampled breath by breath, and the mathematical description of VO2k used a first-order exponential with time delay (TD) on the average of two rest-to-work transitions at WLVO2peak. The mean VO2peak approached 50.2 ± 6.2 mL·kg-1·min-1 and GET and RCP attained (respectively) 67.4 ± 7.3% and 87.4 ± 3.4% VO2peak. The average tLim was 329.5 ± 63.6 s for both sexes, and all swimmers attained VO2peak (100.4 ± 3.8%) when considering the primary response of VO2 (A1' = 91.8 ± 6.7%VO2peak) associated with the VO2 slow component (SC) of 10.7 ± 6.7% of end-exercise VO2, with time constants of 24.4 ± 9.8 s for A1' and 149.3 ± 29.1 s for SC. Negative correlations were observed for tLim to VO2peak, WLVO2peak, GET, RCP, and EEVO2 (r = -0.55, -0.59, -0.58, -0.53, and -0.50). Thus, the VO2k during tethered swimming at WLVO2peak reproduced the physiological responses corresponding to a severe domain. The findings also demonstrated that tLim was inversely related to aerobic conditioning indexes and to the ability to adjust oxidative metabolism to match target VO2 demand during exercise.
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This study sought to assess the relationship between different jumping asymmetries and associated performance variables in high-level male senior and professional football players. Nineteen football players with at least 12 years of training experience (23.2 ± 3.1 years of age; 75.2 ± 4.8 kg of body mass and 181 ± 0.06 cm of height) participated in this study performing countermovement jump (CMJ), squat jump (SJ), single-leg CMJ and drop jump (DJ), associated performance variable eccentric utilization ratio (EUR), stretch-shortening cycle (SSC), bilateral deficit (BLD), and limb symmetry index (LSI) were determined. High correlations were observed between different methodologies of jump tests and associated performance indicators (SSC, BLD, EUR), except LSI. Moreover, CMJ and SJ results were different (p < 0.05), but no differences were found between interlimb in CMJ (p = 0.19) and DJ (p = 0.14). Between the same limbs and different jumps differences were detected in CMJ and DJ (p < 0.01), and it has also been found that the laterality effect size on strength was small in CMJ (ES = 0.30) and DJ (ES = 0.35). LSI between CMJ and DJ was not different despite higher mean values in CMJ, and although mean BLD was positive (>100%), the results highlight the need for individual evaluation since eight players scored negatively. An in-depth and accurate analysis of performance in preseason screening jump tests should be considered, aiming to detect injury risk, specifically evaluating different jumping test methodologies, and determining jumping associated performance variables for each test, namely EUR, SSC, BLD, and LSI. Specific muscle-strengthening exercises could be implemented based on this study results and outcomes, aiming to reduce injury risks and lower extremity asymmetries and to enhance individual football performance in high-level male senior and professional football players. Sports institutions should pay special attention regarding potential health problems in athletes exposed to daily high training loads.
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Glucocorticoids (GCs) administration, such as cortisol acetate (CA) and dexamethasone (DEXA), is used worldwide due to their anti-inflammatory, anti-allergic, and immunosuppressive properties. However, muscle atrophy is one of the primary deleterious induced responses from the chronic treatment with GCs since it stimulates muscle degradation inhibiting muscle protein synthesis. Animal models allow a better understanding of the molecular pathways involved in this process of gene modulation and production of hypertrophic and atrophic proteins. The treatment with GCs, such as DEXA, promotes the reduction of hypertrophic proteins such as serine/threonine tyrosine kinase (AKT), protein kinase mammalian target of rapamycin (mTOR), and ribosomal protein S6 kinase (p70S6K) and increased gene expression or production of atrophic proteins, such as myostatin, muscle atrophic F-box (atrogin-1), or muscle ring finger protein-1 (MuRF-1). In both continuous exercise (CE) and resistance exercise (RE) forms, exercise training is used to mitigate muscle atrophy induced by GCs. The CE attenuated muscle atrophy induced by CA or DEXA in the plantaris and extensor digitorum longus muscles, while RE mitigated the DEXA-induced atrophy in plantaris and flexor hallucis longus muscles. The RE response appears to have occurred by modulation of hypertrophic proteins through increased protein production or phosphorylated/total ratio of mTOR and p70S6K and decreased atrophic protein production of MuRF-1. CE needs future research to understand the molecular pathways of its protective response.
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Glucocorticoides , Proteínas Quinases S6 Ribossômicas 70-kDa , Animais , Glucocorticoides/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/farmacologia , Atrofia Muscular/metabolismo , Músculo Esquelético/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Exercício Físico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Mamíferos/metabolismoRESUMO
The proton is one of the main building blocks of all visible matter in the Universe1. Among its intrinsic properties are its electric charge, mass and spin2. These properties emerge from the complex dynamics of its fundamental constituents-quarks and gluons-described by the theory of quantum chromodynamics3-5. The electric charge and spin of protons, which are shared among the quarks, have been investigated previously using electron scattering2. An example is the highly precise measurement of the electric charge radius of the proton6. By contrast, little is known about the inner mass density of the proton, which is dominated by the energy carried by gluons. Gluons are hard to access using electron scattering because they do not carry an electromagnetic charge. Here we investigated the gravitational density of gluons using a small colour dipole, through the threshold photoproduction of the J/ψ particle. We determined the gluonic gravitational form factors of the proton7,8 from our measurement. We used a variety of models9-11 and determined, in all cases, a mass radius that is notably smaller than the electric charge radius. In some, but not all cases, depending on the model, the determined radius agrees well with first-principle predictions from lattice quantum chromodynamics12. This work paves the way for a deeper understanding of the salient role of gluons in providing gravitational mass to visible matter.
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INTRODUCTION: This study aimed to compare athletes practicing exercise in different environments with non-active young and elderly men and women regarding bone mineral density (BMD), hypothesizing that BMD values differ between athletes according to the environment of exercise practice, but those training in a low-gravitational environment have no different stimuli to BMD increasing if compared with healthy peers experiencing reduced exercise involvement, whatever the age group and sex. MATERIALS AND METHODS: 104 participants of both sexes were selected according to the environment of exercise practice [swimmers (N = 26) and judo fighters (N = 26)], and exercise level of involvement [non-active young (N = 26) and older adults (N = 26)]. Dual-energy X-ray absorptiometry provided BMD, lean mass, and fat mass (FM) for the whole body (WB), upper (UL), and lower limbs (LL). RESULTS: For the BMD in WB, UL and LL no effects of group and sex were observed (p > 0.05). Post-hoc analyses detected higher values of BMD in UL for female swimmers compared to non-active older adults (p < 0.05), while judo fighters showed higher BMD in WB, UL, and LL than other participants whatever the sex (p < 0.01). Lower FM was observed for WB, UL, and LL when swimmers and judo fighters were compared to non-active young and older female peers (p < 0.01). CONCLUSION: The findings emphasized that BMD stimuli with swimming are reduced when compared to judo, and despite the stimuli in swimming is not distinguishable from that affecting BMD in WB, UL and LL of non-active young, it is effective in differing BMD in UL among non-active older for women.
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Composição Corporal , Osso e Ossos , Masculino , Humanos , Feminino , Idoso , Densidade Óssea , Absorciometria de Fóton , Natação , MineraisRESUMO
INTRODUCTION: Currently, there is an increase in people practicing freediving (FD) both in competition and leisure. As a sports practice, its modalities are grouped into static, dynamic, and constant weight apnea. The aim of this systematic review and meta-analysis (PROSPERO-CRD42021230322) was to identify the training methods used to improve the static apnea time (AT) performance. EVIDENCE ACQUISITION: Ten training protocols were analyzed from eight studies published until March 09, 2022. The effect size (Hedge's g) and its confidence interval (CI
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Apneia , Mergulho , Masculino , Feminino , Humanos , Apneia/terapia , Suspensão da Respiração , Exercício Físico , Terapia por ExercícioRESUMO
The time sustained during exercise with oxygen uptake (VÌO2) reaching maximal rates (VÌO2peak) or near peak responses (i.e., above second ventilatory threshold [t@VT2) or 90% VÌO2peak (t@90%VÌO2peak)] is recognized as the training pace required to enhance aerobic power and exercise tolerance in the severe domain (time-limit, tLim). This study compared physiological and performance indexes during continuous and intermittent trials at maximal aerobic velocity (MAV) to analyze each exercise schedule, supporting their roles in conditioning planning. Twenty-two well-trained swimmers completed a discontinuous incremental step-test for VÌO2peak, VT2, and MAV assessments. Two other tests were performed in randomized order, to compare continuous (CT) vs. intermittent trials (IT100) at MAV until exhaustion, to determine peak oxygen uptake (Peak-VÌO2) and VÌO2 kinetics (VÌO2K). Distance and time variables were registered to determine the tLim, t@VT2, and t@90%VÌO2peak tests. Blood lactate concentration ([La-]) was analyzed, and rate of perceived exertion (RPE) was recorded. The tests were conducted using a breath-by-breath apparatus connected to a snorkel for pulmonary gas sampling, with pacing controlled by an underwater visual pacer. VÌO2peak (55.2 ± 5.6 ml·kg·min-1) was only reached in CT (100.7 ± 3.1 %VÌO2peak). In addition, high VÌO2 values were reached at IT100 (96.4 ± 4.2 %VÌO2peak). VÌO2peak was highly correlated with Peak-VÌO2 during CT (r = 0.95, p < 0.01) and IT100 (r = 0.91, p < 0.01). Compared with CT, the IT100 presented significantly higher values for tLim (1,013.6 ± 496.6 vs. 256.2 ± 60.3 s), distance (1,277.3 ± 638.1 vs. 315.9 ± 63.3 m), t@VT2 (448.1 ± 211.1 vs. 144.1 ± 78.8 s), and t@90%VÌO2peak (321.9 ± 208.7 vs. 127.5 ± 77.1 s). VÌO2K time constants (IT100: 25.9 ± 9.4 vs. CT: 26.5 ± 7.5 s) were correlated between tests (r = 0.76, p < 0.01). Between CT and IT100, tLim were not related, and RPE (8.9 ± 0.9 vs. 9.4 ± 0.8) and [La-] (7.8 ± 2.7 vs. 7.8 ± 2.8 mmol·l-1) did not differ between tests. MAV is suitable for planning swimming intensities requiring VÌO2peak rates, whatever the exercise schedule (continuous or intermittent). Therefore, the results suggest IT100 as a preferable training schedule rather than the CT for aerobic capacity training since IT100 presented a significantly higher tLim, t@VT2, and t@90%VÌO2peak (â¼757, â¼304, and â¼194 s more, respectively), without differing regards to [La-] and RPE. The VÌO2K seemed not to influence tLim and times spent near VÌO2peak in both workout modes.
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We report a precise measurement of the parity-violating (PV) asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{48}Ca. We measure A_{PV}=2668±106(stat)±40(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(q=0.8733 fm^{-1})=0.1304±0.0052(stat)±0.0020(syst) and the charge minus the weak form factor F_{ch}-F_{W}=0.0277±0.0055. The resulting neutron skin thickness R_{n}-R_{p}=0.121±0.026(exp)±0.024(model) fm is relatively thin yet consistent with many model calculations. The combined CREX and PREX results will have implications for future energy density functional calculations and on the density dependence of the symmetry energy of nuclear matter.
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Resistance training (RT) has been considered an intervention with effective stimulus on bone mineral formation and is, therefore, recommended to decrease the rate of bone morpho-functional proprieties loss with aging. Thus, this meta-analysis aimed to analyze the effectiveness of RT protocols in promoting changes in bone mineral density (BMD) in older adults. The systematic reviews and meta-analysis followed the PRISMA guidelines (PROSPERO CRD42020170859). The searches were performed in the electronic databases using descriptors according to the PICO strategy. The methodological quality and risk of bias were assessed with the PEDro scale, and the magnitude of the results was determined by Hedges' g. Seven studies involving 370 elderlies, with the RT planned as a unique exercise mode of intervention, showed designs with four to five exercises for upper- and lower-limbs musculature, two to three sets per exercise, eight to twelve repetitions to failure at 70-90% 1 RM, 60-120 s of rest between sets, and executed three times per week for 12-52 weeks. The RT protocols were classified between good and excellent and evidenced a positive effect on the BMD at the hip (0.64%) and spine (0.62%) but not in the femoral neck (-0.22%) regardless of the intervention length. The narrow range of either positive or negative changes in the BMD after the RT intervention support, at best, a preventive effect against the increasing risk of bone frailty in an older population, which is evident beyond 12 weeks of RT practice engagement.
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BACKGROUND: Older companion dogs naturally develop a dementia-like syndrome with biological, clinical and therapeutic similarities to Alzheimer disease (AD). Given there has been no new safe, clinically effective and widely accessible treatment for AD for almost 20 years, an all-new cell therapeutic approach was trialled in canine veterinary patients, and further modelled in aged rats for more detailed neurobiological analysis. METHODS: A Phase 1/2A veterinary trial was conducted in N = 6 older companion dogs with definitive diagnosis of Canine Cognitive Dysfunction (CCD). Treatment comprised direct microinjection of 250,000 autologous skin-derived neuroprecursors (SKNs) into the bilateral hippocampus using MRI-guided stereotaxis. Safety was assessed clinically and efficacy using the validated Canine Cognitive Dysfunction Rating Scale (CCDR) at baseline and 3-month post treatment. Intention to treat analysis imputed a single patient that had a surgical adverse event requiring euthanasia. Three dog brains were donated following natural death and histology carried out to quantify Alzheimer pathology as well as immature neurons and synapses; these were compared to a brain bank (N = 12) of untreated aged dogs with and without CCD. Further, an age-related memory dysfunction rat model (N = 16) was used to more closely evaluate intrahippocampal engraftment of canine SKN cells, focusing on mnemonic and synaptic effects as well as donor cell survival, neurodifferentation and electrophysiologic circuit integration in a live hippocampal slice preparation. RESULTS: Four out-of-five dogs improved on the primary clinical CCDR endpoint, three fell below diagnostic threshold, and remarkably, two underwent full syndromal reversal lasting up to 2 years. At post mortem, synaptic density in the hippocampus specifically was nine standard deviations above non-treated dogs, and intensity of new neurons also several fold higher. There was no impact on AD pathology or long-term safety signals. Modelling in aged rats replicated the main canine trial findings: hippocampally-dependent place memory deficits were reversed and synaptic depletion rescued. In addition, this model confirmed donor cell survival and migration throughout the hippocampus, neuronal differentiation in situ, and physiologically-correct integration into pyramidal layer circuits. CONCLUSIONS: With further development, SKN cell therapy may have potential for treating carefully chosen AD patients based on neurosynaptic restoration in the hippocampus.
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Doença de Alzheimer , Terapia Baseada em Transplante de Células e Tecidos , Doenças do Cão , Animais , Cães , Doença de Alzheimer/terapia , Doença de Alzheimer/veterinária , Doenças do Cão/terapia , Hipocampo/patologia , Células-Tronco Neurais/transplanteRESUMO
We report the first measurement of the parity-violating elastic electron scattering asymmetry on ^{27}Al. The ^{27}Al elastic asymmetry is A_{PV}=2.16±0.11(stat)±0.16(syst) ppm, and was measured at ⟨Q^{2}⟩=0.02357±0.00010 GeV^{2}, ⟨θ_{lab}⟩=7.61°±0.02°, and ⟨E_{lab}⟩=1.157 GeV with the Q_{weak} apparatus at Jefferson Lab. Predictions using a simple Born approximation as well as more sophisticated distorted-wave calculations are in good agreement with this result. From this asymmetry the ^{27}Al neutron radius R_{n}=2.89±0.12 fm was determined using a many-models correlation technique. The corresponding neutron skin thickness R_{n}-R_{p}=-0.04±0.12 fm is small, as expected for a light nucleus with a neutron excess of only 1. This result thus serves as a successful benchmark for electroweak determinations of neutron radii on heavier nuclei. A tree-level approach was used to extract the ^{27}Al weak radius R_{w}=3.00±0.15 fm, and the weak skin thickness R_{wk}-R_{ch}=-0.04±0.15 fm. The weak form factor at this Q^{2} is F_{wk}=0.39±0.04.
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We report precision determinations of the beam-normal single spin asymmetries (A_{n}) in the elastic scattering of 0.95 and 2.18 GeV electrons off ^{12}C, ^{40}Ca, ^{48}Ca, and ^{208}Pb at very forward angles where the most detailed theoretical calculations have been performed. The first measurements of A_{n} for ^{40}Ca and ^{48}Ca are found to be similar to that of ^{12}C, consistent with expectations and thus demonstrating the validity of theoretical calculations for nuclei with Z≤20. We also report A_{n} for ^{208}Pb at two new momentum transfers (Q^{2}) extending the previous measurement. Our new data confirm the surprising result previously reported, with all three data points showing significant disagreement with the results from the Z≤20 nuclei. These data confirm our basic understanding of the underlying dynamics that govern A_{n} for nuclei containing â²50 nucleons, but point to the need for further investigation to understand the unusual A_{n} behavior discovered for scattering off ^{208}Pb.