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1.
Medicina (Kaunas) ; 59(4)2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-37109676

RESUMO

Myalgic encephalomyelitis/chronic fatigue (ME/CFS) is a post-infectious, chronic disease that can lead to severe impairment and, even, total disability. Although the disease has been known for a long time, and has been coded in the ICD since 1969 (G93.3), medical research has not yet been able to reach a consensus regarding its physiological basis and how best to treat it. Against the background of these shortcomings, psychosomatic disease models have been developed and psychotherapeutic treatments have been derived from them, but their empirical testing has led to sobering results. According to the current state of research, psychotherapy and psychosomatic rehabilitation have no curative effect in the treatment of ME/CFS. Nevertheless, we see numerous patients in practices and outpatient clinics who suffer severely as a result of their illness and whose mental well-being and coping strategies would benefit from psychotherapeutic help. In this article, we outline a psychotherapeutic approach that serves this need, taking into account two basic characteristics of ME/CFS: firstly, the fact that ME/CFS is a physical illness and that curative treatment must therefore be physical; and secondly, the fact that post exertional malaise (PEM) is a cardinal symptom of ME/CFS and thus warrants tailored psychotherapeutic attention.


Assuntos
Síndrome de Fadiga Crônica , Humanos , Síndrome de Fadiga Crônica/terapia , Psicoterapia
2.
Palliat Med ; 36(1): 105-113, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34479451

RESUMO

BACKGROUND: The COVID-19 pandemic has posed significant challenges for healthcare systems to meet patients' and families' complex care needs, including spiritual care needs. Little data are available about spiritual care delivery in light of the pandemic. AIM: This study examined the impact of COVID-19 on spiritual care by healthcare chaplains in the United States. DESIGN: An online survey of 563 board-certified chaplains was conducted from March to July 2020. The survey, designed to identify chaplains' roles in facilitating conversations about goals of care, included an open-ended question asking how COVID-19 affected chaplaincy practices; 236 chaplains responded. Quantitative data and written qualitative responses were analyzed using descriptive analysis and content analysis, respectively. SETTING/PARTICIPANTS: Majority of participants were white (88%), female (59%), Protestant (53%), and employed full time (86%). Almost half were working in community hospitals (45%) and designated to one or more special units (48%) including ICU, palliative care, and oncology. RESULTS: Three major themes emerged from chaplains' qualitative responses: (1) COVID-19-related risk mitigation and operational changes; (2) impact of social distancing guidelines; and (3) increased need for and provision of psychosocial and spiritual support. CONCLUSIONS: Chaplains reported that COVID-19 challenges contributed to greater social isolation, and mental health concerns for patients, families, and healthcare staff, and substantially changed the way healthcare chaplains provided spiritual care. With evolving healthcare contexts, developing safer, more creative modes of spiritual care delivery while offering systematic support for chaplains can help meet the increasing psychosocial and spiritual needs of patients, families, and healthcare team members.


Assuntos
COVID-19 , Serviço Religioso no Hospital , Assistência Religiosa , Terapias Espirituais , Clero , Atenção à Saúde , Feminino , Humanos , Pandemias , SARS-CoV-2 , Estados Unidos
3.
Palliat Support Care ; : 1-8, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36373502

RESUMO

OBJECTIVES: Advance care planning (ACP) conversations require the consideration of deeply held personal values and beliefs and the discussion of uncertainty, fears, and hopes related to current and future personal healthcare. However, empirical data are limited on how such spiritual concerns and needs are supported during ACP. This study explored board-certified healthcare chaplains' perspectives of patients' spiritual needs and support in ACP conversations. METHODS: An online survey of 563 board-certified chaplains was conducted from March to July 2020. The survey included 3 open-ended questions about patients' hopes and fears and about how the chaplains addressed them during ACP conversations. Written qualitative responses provided by 244 of the chaplains were examined with content analysis. RESULTS: The majority of the 244 chaplains were White (83.6%), female (59%), Protestant (63.1%), and designated to one or more special care units (89.8%). Major themes on patients' hopes and fears expressed during ACP were (1) spiritual, religious, and existential questions; (2) suffering, peace, and comfort; (3) focus on the present; (4) hopes and fears for family; and (5) doubt and distrust. Major themes on how chaplains addressed them were (1) active listening to explore and normalize fears, worries, and doubts; (2) conversations to integrate faith, values, and preferences into ACP; and (3) education, empowerment, and advocacy. SIGNIFICANCE OF RESULTS: ACP conversations require deep listening and engagement to address patients' spiritual needs and concerns - an essential dimension of engaging in whole-person care - and should be delivered with an interdisciplinary approach to fulfill the intended purpose of ACP.

4.
Psychosom Med ; 83(7): 756-766, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34297004

RESUMO

OBJECTIVE: High cardiovascular reactions to psychological stress are associated with the development of hypertension, systemic atherosclerosis, and cardiovascular disease. However, it has become apparent that low biological stress reactivity also may have serious consequences for health, although less is known about the mechanisms of this. The objectives of this narrative review and opinion article are to summarize and consider where we are now in terms of the usefulness of the reactivity hypothesis and reactivity research, given that both ends of the reactivity spectrum seem to be associated with poor health, and to address some of the key criticisms and future challenges for the research area. METHODS: This review is authored by the members of a panel discussion held at the American Psychosomatic Society meeting in 2019, which included questions such as the following: How do we measure high and low reactivity? Can high reactivity ever indicate better health? Does low or blunted reactivity simply reflect less effort on task challenges? Where does low reactivity originate from, and what is a low reactor? RESULTS: Cardiovascular (and cortisol) stress reactivity are used as a model to demonstrate an increased understanding of the different individual pathways from stress responses to health/disease and show the challenges of how to understand and best use the reconstruction of the long-standing reactivity hypothesis given recent data. CONCLUSIONS: This discussion elucidates the gaps in knowledge and key research issues that still remain to be addressed in this field, and that systematic reviews and meta-analyses continue to be required.


Assuntos
Sistema Cardiovascular , Hipertensão , Humanos , Hidrocortisona , Estresse Psicológico
5.
J Shoulder Elbow Surg ; 30(12): 2839-2844, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34118420

RESUMO

BACKGROUND: Decreases in bone density of the scapula due to age and disease can make orthopedic procedures such as arthroplasty and fracture fixation challenging. There is limited information in the literature regarding the effect of age and sex on the patterns of these density changes across the bone. Characterizing these changes could assist the surgeon in planning optimal instrumentation placement. METHODS: Ninety-seven 3-dimensional models of the scapula were segmented from routine clinical computed tomography scans, and an opportunistic quantitative computed tomography approach was used to obtain detailed calibrated bone density measurements for each bone model. The effects of age and sex on cortical and trabecular bone density were assessed for the entire scapula. Specific regions (eg, scapular spine) where these factors had a significant effect were identified. Three-dimensional models were generated to allow clear visualization of the changes in density patterns. RESULTS: Cortical bone loss averaged 1.0 mg/cm3 and 0.3 mg/cm3 per year for female and male subjects, respectively, and trabecular bone loss averaged 1.6 mg/cm3 and 1.2 mg/cm3, respectively. However, several regions had loss rates several times greater. Areas that were significantly affected by age included the acromion, scapular spine, base of the coracoid, inferior glenoid neck, and glenoid vault. Areas that were significantly affected by sex were the scapular spine and body. CONCLUSIONS: These findings provide evidence that the bone density distribution across the scapula changes non-uniformly because of factors including sex and age. Despite overall trends of bone loss, there remains significant variability between individuals, and subject-specific tools for planning surgical procedures in which scapular fixation is required may be beneficial.


Assuntos
Densidade Óssea , Articulação do Ombro , Acrômio , Feminino , Humanos , Masculino , Escápula/diagnóstico por imagem , Ombro
6.
J Strength Cond Res ; 34(4): 1176-1183, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32213785

RESUMO

Malone, S, Hughes, B, Roe, M, Mangan, S, and Collins, K. Factors that influence session-rating of perceived exertion in elite Gaelic football. J Strength Cond Res 34(4): 1176-1183, 2020-The current investigation examined the relationships between external training load (TL) measures and the session rating of perceived exertion (s-RPE) within Gaelic football players. Furthermore, we examined the effect that player experience, playing position, and 1-km time trial (TT) performance had on perception of TL. Physical performance (total distance, high-speed distance, very high-speed distance, max velocity, total accelerations, and maximal velocity exposures) and perceived TL (s-RPE) data were collected from 45 elite intercounty Gaelic football players (mean ± SD age of 24.2 ± 2.9 years; height: 180 ± 7 cm; mass: 81 ± 7 kg) over a 1-year period this resulted in 4,095 individual training session data being collected. There were moderate to very large associations between s-RPE and distance measures. Post hoc analysis revealed that the 0-1-year group had a higher s-RPE TL than the 2-3-year (d = 0.84 ± 0.33, small), 4-6-year (d = 0.91 ± 0.30, small), and 7+ year (d = 0.81 ± 0.30, small) groups. Midfielders reported higher s-RPE when compared with all positions (d = 1.21 ± 0.21, moderate). Half-backs (d = 0.81 ± 0.30, small), and half-forwards (d = 0.84 ± 0.31, small) had a higher s-RPE TL than the full-backs and full-forwards when external TL was accounted for (d = 1.21 ± 0.58, moderate). When aerobic fitness was considered, a 1.2% AU increase in s-RPE TL per 1 second increase in TT time (90% confidence limits: 1.07-2.64) when external TL was held constant was observed. The current investigation has shown moderate to very large associations between s-RPE and distance measures. When experience and fitness were considered as potential moderators of TL, it was observed that a given external TL may result in different internal responses between athletes. This potentially leaves individuals at risk of overtraining or failing to elicit positive adaptation. It is therefore vital that coaches and trainers give consideration to these mediators of s-RPE TL.


Assuntos
Desempenho Atlético , Condicionamento Físico Humano , Esforço Físico , Aptidão Física , Adulto , Humanos , Masculino , Aceleração , Desempenho Atlético/fisiologia , Irlanda , Percepção , Condicionamento Físico Humano/métodos , Esforço Físico/fisiologia , Aptidão Física/fisiologia , Aptidão Física/psicologia , Esportes de Equipe
7.
J Strength Cond Res ; 34(1): 225-234, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29985218

RESUMO

Malone, S, Hughes, B, Collins, K, and Akubat, I. Methods of monitoring training load and their association with changes across fitness measures in hurling players. J Strength Cond Res 34(1): 225-234, 2020-The aim of the current investigation was to assess the dose-response relationship for various methods of monitoring training load (TL) and changes in aerobic and anaerobic fitness in hurling players. Training and match load measures were collected from 30 hurling players (speed at different blood lactate [vLT, vOBLA], maximal oxygen uptake [VO2max], speed at VO2max [vVO2max], peak treadmill velocity [PTV] running economy [RE] Yo-Yo intermittent recovery test (Yo-YoIR1, Yo-YoIR2), speed at 5, 10 , 20 m, and repeated sprint ability [6 × 35 m]) before and after during a 12-week in-season period. Mean weekly training and match loads as determined by s-RPE, bTRIMP, luTRIMP, eTRIMP, iTRIMP, and gTRIMP were correlated with each other, percentage change in VO2max, vVO2max, RE, PTV, the speed at blood lactate concentrations of 2 mmol·L (vLT) and 4 mmol·L (vOBLA), and YoYoIR1, Yo-YoIR2 performance. iTRIMP showed a trivial association with s-RPE and a small to moderate association with other heart rate-based methods. Small to large changes (effect size: 0.38-1.12) were observed in aerobic and anaerobic fitness measures were observed across the 12-week period. Trivial to very large associations (r = 0.11-0.78) were observed between TL variables and changes in fitness depending on the variable analyzed. iTRIMP was shown to have large to very large associations with changes in vOBLA {r = 0.78 (95% confidence interval [CI]: 0.71-0.88)}, VO2max (r = 0.77 [95% CI: 0.68-0.82]), RE (r = 0.77 [95% CI: 0.67-0.82]), Yo-YoIR1 (r = 0.69 [95% CI: 0.51-0.72]), and RSAb (r = 0.66 [95% CI: 0.60-0.72]) with moderate associations reported between iTRIMP and other variables. All other measures of TL showed trivial to moderate associations (r = 0.11-0.66). The current investigation shows that fully individualized training load (iTRIMP) measures may potentially offer a better understanding of dose-response relationships when compared with subjective and nonindividualized measures of TL to changes in aerobic and anaerobic fitness in team sports athletes; as such, it may be suggested that practitioners should use individualized measures of TL assessment within their day-to-day practices.


Assuntos
Condicionamento Físico Humano/métodos , Esforço Físico , Aptidão Física/fisiologia , Esportes/fisiologia , Adulto , Teste de Esforço , Frequência Cardíaca , Humanos , Ácido Láctico/sangue , Consumo de Oxigênio , Corrida , Adulto Jovem
9.
Glob Chang Biol ; 25(12): 4105-4115, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31554025

RESUMO

Commercial shellfish aquaculture is vulnerable to the impacts of ocean acidification driven by increasing carbon dioxide (CO2 ) absorption by the ocean as well as to coastal acidification driven by land run off and rising sea level. These drivers of environmental acidification have deleterious effects on biomineralization. We investigated shell biomineralization of selectively bred and wild-type families of the Sydney rock oyster Saccostrea glomerata in a study of oysters being farmed in estuaries at aquaculture leases differing in environmental acidification. The contrasting estuarine pH regimes enabled us to determine the mechanisms of shell growth and the vulnerability of this species to contemporary environmental acidification. Determination of the source of carbon, the mechanism of carbon uptake and use of carbon in biomineral formation are key to understanding the vulnerability of shellfish aquaculture to contemporary and future environmental acidification. We, therefore, characterized the crystallography and carbon uptake in the shells of S. glomerata, resident in habitats subjected to coastal acidification, using high-resolution electron backscatter diffraction and carbon isotope analyses (as δ13 C). We show that oyster families selectively bred for fast growth and families selected for disease resistance can alter their mechanisms of calcite crystal biomineralization, promoting resilience to acidification. The responses of S. glomerata to acidification in their estuarine habitat provide key insights into mechanisms of mollusc shell growth under future climate change conditions. Importantly, we show that selective breeding in oysters is likely to be an important global mitigation strategy for sustainable shellfish aquaculture to withstand future climate-driven change to habitat acidification.


Assuntos
Biomineralização , Ostreidae , Animais , Calcificação Fisiológica , Concentração de Íons de Hidrogênio , Água do Mar
10.
Nano Lett ; 18(3): 1826-1830, 2018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29420900

RESUMO

Recent developments in spin-orbit torques allow for highly efficient current-driven domain wall (DW) motion in nanowires with perpendicular magnetic anisotropy. Here, we show that chiral DWs can be driven into nonequilibrium states that can persist over tens of nanoseconds in Y-shaped magnetic nanowire junctions that have an input and two symmetric outputs. A single DW that is injected into the input splits and travels at very different velocities in the two output branches until it reaches its steady-state velocity. We find that this is due to the disparity between the fast temporal evolution of the spin current derived spin-orbit torque and a much-slower temporal evolution of the DMI-derived torque. Changing the DW polarity inverts the velocity asymmetry in the two output branches, a property that we use to demonstrate the sorting of domains.

11.
Nano Lett ; 18(7): 4074-4080, 2018 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-29905078

RESUMO

Three-terminal spintronic memory devices based on the controlled manipulation of the proximate magnetization of a magnetic nanoelement using spin-orbit torques (SOTs) have attracted growing interest recently. These devices are nonvolatile, can operate at high speeds with low error rates, and have essentially infinite endurance, making them promising candidates for high-speed cache memory. Typically, the magnetization and spin polarization in these devices are collinear to one another, leading to a finite incubation time associated with the switching process. While switching can also be achieved when the magnetization easy axis and spin polarization are noncollinear, this requires the application of an external magnetic field for deterministic switching. Here, we demonstrate a novel SOT scheme that exploits non-uniform micromagnetic states to achieve deterministic switching when the spin polarization and magnetic moment axis are noncollinear to one another in the absence of external magnetic field. We also explore the use of a highly efficient SOT generator, oxygen-doped tungsten in the three-terminal device geometry, confirming its -50% spin Hall angle. Lastly, we illustrate how this scheme may potentially be useful for nanomagnetic logic applications.

12.
J Strength Cond Res ; 33(1): 180-187, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28277429

RESUMO

Malone, S, Hughes, B, and Collins, K. The influence of exercise-to-rest ratios on physical and physiological performance during hurling-specific small-sided games. J Strength Cond Res 33(1): 180-187, 2019-The current study examined the impact of different exercise-to-rest ratios on hurling-specific small-sided games (SSG). Thirty-four (n = 34) hurling players were monitored during an in-season training period. Heart rate (Polar Electro Oy, Kempele, Finland) and global positioning system technology (4-Hz; VX Sport, Lower Hutt, New Zealand) were used to analyze the physical and physiological differences between exercise-to-rest ratios across bouts of SSG. Total distance (m), high-speed distance (m) (≥17 km·h), very high-speed distance (≥22 km·h) (m), total accelerations (n), acceleration distance (m), peak velocity (km·h), and % maximum heart rate (%HRmax) were measured. Exercise-to-rest ratios of 2:1 (d = 0.65 ± 0.12; moderate), and 1:1 (d = 0.43 ± 0.12; small), resulted in significant reductions in high-speed distance, very high-speed distance, and acceleration distance. Exercise-to-rest ratios of 1:2 (d = 0.63 ± 0.21; moderate), and 1:3 (d = 1.23 ± 0.22; large), resulted in increased high-speed distance, very high-speed distance, and acceleration distance, but only after the third bout. The first bout of SSG resulted in the lowest %HRmax when compared with all other bouts (d = 0.63 ± 0.22; moderate). A significant bout-to-bout increase in %HRmax independent of exercise-to-rest ratio (d = 0.25 ± 0.04; small) was observed. Exercise-to-rest ratios of 2:1 (d = 0.65 ± 0.14; moderate), and 1:1 (d = 0.65 ± 0.24; moderate), resulted in significantly higher %HRmax during all SSG bouts; however, exercise-to-rest ratios of 1:2 (d = 0.25 ± 0.04; small), and 1:3 (d = 0.15 ± 0.04; trivial), resulted in lower %HRmax during SSG. Coaches should be aware that reducing the rest between bouts of SSGs (2:1 and 1:1 exercise-to-rest ratios) increases the physiological response (%HRmax) with reduced high-speed running performances. Coaches now have data to allow them tp best prepare for session needs with regard to specific SSG exercise-to-rest ratios.


Assuntos
Desempenho Atlético/fisiologia , Exercício Físico/fisiologia , Descanso , Esportes/fisiologia , Aceleração , Adulto , Comportamento Competitivo , Sistemas de Informação Geográfica , Frequência Cardíaca , Humanos , Masculino , Monitorização Fisiológica , Corrida/fisiologia , Adulto Jovem
13.
J Strength Cond Res ; 33(3): 825-830, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28570496

RESUMO

Malone, S, Hughes, B, and Collins, K. Effect of training load distribution on aerobic fitness measures in hurling players. J Strength Cond Res 33(3): 825-830, 2019-The aim of the current investigation was to quantify the training intensity distribution of hurling players and their association with changes in aerobic fitness measures within hurling players. Thirty hurling players (n = 30; age 26.5 ± 3.2 years; height 178.9 ± 3.2 cm; body mass 81.5 ± 4.5 kg) were observed during the pre-championship training period (12 weeks). Aerobic fitness measures (V[Combining Dot Above]O2max), peak treadmill velocity (km·h), heart rates (HRs) at 2 and 4 mmol·L blood lactate concentrations, and Yo-Yo intermittent recovery test performance (Yo-YoIR1) were assessed before and after the training period. Training intensities were categorized using 3 individualized HR zones based on the following criteria: low intensity (≤HR 2 mmol·L), moderate intensity (between HR 2 and 4 mmol·L), and high intensity (≥HR 4 mmol·L). Analysis of 1,025 individual training sessions showed that players spent 58.1 ± 2.5%, 24.3 ± 2.9%, and 17.6 ± 1.3% of time in the low-, moderate-, and high-intensity zones, respectively. The training time spent at high intensity (Zone 3) showed moderate-to-large associations with improvements in S2 (r = 0.80; p = 0.04) and S4 (r = 0.58; p = 0.03). Similar trends were observed for time spent in high intensity and improvements in V[Combining Dot Above]O2max (r = 0.77; p = 0.001) and Yo-YoIR1 performance (r = 0.65; p = 0.05). Hurling players have been shown to spend the majority of training time in low (≤ HR 2 mmol·L) to moderate intensity (between HR 2 and 4 mmol·L) training. However, only the time spent at high intensity (≥90% of maximal HR) was related to changes in aerobic fitness. These results support the usefulness of the quantification of aerobic training load using HR. The study also supports the efficacy of spending elements of training time within the high-intensity zone to increase hurling player's aerobic fitness characteristics.


Assuntos
Aptidão Cardiorrespiratória/fisiologia , Treinamento Intervalado de Alta Intensidade/métodos , Esportes/fisiologia , Adulto , Teste de Esforço , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Consumo de Oxigênio/fisiologia , Aptidão Física/fisiologia , Adulto Jovem
14.
J Strength Cond Res ; 33(9): 2513-2522, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29401193

RESUMO

McGuinness, A, Malone, S, Hughes, B, and Collins, K. Physical activity and physiological profiles of elite international female field hockey players across the quarters of competitive match play. J Strength Cond Res 33(9): 2513-2522, 2019-The aim of the current investigation was to quantify the physical and physiological demands of elite international female field hockey across the quarters of match-play. Twenty-seven elite international female field hockey outfield players (23 ± 3 years; 162.6 ± 13.0 cm; 66.0 ± 6.0 kg) participated in the current observational study during the 2016-2017 season. Participants were monitored using global positioning system technology and HR monitors. Players were categorized based on 3 different playing positions. Activity was categorized into total distance (in meters), relative total distance (m·min), low-, moderate-, and high-intensity distance (m), maximum velocity (km·h), and percentage maximal velocity (%). Physiological demands were quantified through players peak heart rate (HRPeak), which was classified based on the player's individual HRmax determined using a Yo-Yo intermittent recovery level 1 test. Players spent on average 38 ± 8 minutes in match play. The total distance covered was 4,847 ± 583 m (127.6 ± 15.6 m·min). Defenders covered a greater total distance across all 3 positions (p = ≤ 0.05). The midfielders covered a greater moderate-intensity distance (p ≤ 0.001), whereas the forwards covered more high-intensity distance (p ≤ 0.001). The HRpeak of the players was 198 ± 4 b·min with a mean exercise intensity of 95 ± 1% HRmax. The time spent >70% HRmax decreased significantly across the quarters (p = 0.01, η = 0.03). Defenders were found to spend more time >85% HRmax when compared with other positions (p ≤ 0.001, η = 0.28). The current study provides normative data that coaches should consider when developing training drills to better optimize the positional physical and physiological activity profiles that best replicate match play.


Assuntos
Desempenho Atlético/fisiologia , Hóquei/fisiologia , Esforço Físico/fisiologia , Corrida/fisiologia , Adulto , Feminino , Sistemas de Informação Geográfica , Frequência Cardíaca , Humanos , Adulto Jovem
16.
Regul Toxicol Pharmacol ; 92: 128-137, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29162533

RESUMO

Di 2-ethylhexyl cyclohexane-1,4-dicarboxylate (DEHCH, CAS 84731-70-4) is an ester of polycarboxylic acid assessed in a variety of mammalian toxicity assays as a substitute for phthalate ester-type plasticizers. An OECD 422 combined systemic toxicity study with a reproductive/developmental toxicity screening test in SD rats found minimal effects on the liver, spleen, and thyroid and no indication that DEHCH is a developmental or reproductive toxicant. In a 90-day feeding study in SD rats, no toxicologically relevant effects were noted. Low genotoxic potential of DEHCH is indicated by the lack of mutagenicity or clastogenicity in vitro. No studies assessing mode of action were identified. Where data gaps exist for DEHCH, a read-across approach was used to assess other toxicological endpoints of interest. Di-ethylhexyl terephthalate (DEHT, CAS 6422-86-2) and 1,2-cyclohexane dicarboxylic acid, diisononyl ester (DINCH, CAS 474919-59-0) have higher tiered studies to supplant the data lacking for health-based standard setting. DEHT and DINCH were chosen as the source substances due to similar physical/chemical properties and thus anticipated metabolism and toxicological characteristics. An oral reference dose (RfD) for DEHCH was calculated using the human equivalent NOAEL from the OECD 422 study. A total uncertainty factor of 100 was comprised of interspecies (3x), intraspecies (10x), subchronic to chronic (1x), LOAEL to NOAEL uncertainty (1x) and database uncertainty (3x) factors, resulting in an RfD of 0.3 mg/kg-day.


Assuntos
Ácidos Dicarboxílicos/administração & dosagem , Dietilexilftalato/administração & dosagem , Ácidos Ftálicos/administração & dosagem , Plastificantes/administração & dosagem , Administração Oral , Animais , Feminino , Humanos , Masculino , Mutagênicos/administração & dosagem , Nível de Efeito Adverso não Observado , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Testes de Toxicidade/métodos
17.
Proc Natl Acad Sci U S A ; 112(21): 6585-90, 2015 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-25971730

RESUMO

Spin-polarized charge currents induce magnetic tunnel junction (MTJ) switching by virtue of spin-transfer torque (STT). Recently, by taking advantage of the spin-dependent thermoelectric properties of magnetic materials, novel means of generating spin currents from temperature gradients, and their associated thermal-spin torques (TSTs), have been proposed, but so far these TSTs have not been large enough to influence MTJ switching. Here we demonstrate significant TSTs in MTJs by generating large temperature gradients across ultrathin MgO tunnel barriers that considerably affect the switching fields of the MTJ. We attribute the origin of the TST to an asymmetry of the tunneling conductance across the zero-bias voltage of the MTJ. Remarkably, we estimate through magneto-Seebeck voltage measurements that the charge currents that would be generated due to the temperature gradient would give rise to STT that is a thousand times too small to account for the changes in switching fields that we observe.

18.
J Strength Cond Res ; 32(5): 1342-1351, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28557851

RESUMO

Malone, S, Mendes, B, Hughes, B, Roe, M, Devenney, S, Collins, K, and Owen, A. Decrements in neuromuscular performance and increases in creatine kinase impact training outputs in elite soccer players. J Strength Cond Res 32(5): 1342-1351, 2018-The aim of the current investigation was to understand the impact of pretraining neuromuscular performance and creatine kinase (CK) status on subsequent training performance in elite soccer players. Thirty soccer players (age: 25.3 ± 3.1 years; height: 183 ± 7 cm; mass: 72 ± 7 kg) were involved in this observational study. Each morning before training, players completed assessments for neuromuscular performance (countermovement jump; CMJ) and CK levels. Global positioning technology provided external load: total distance, high-speed distance, sprint distance, accelerations, decelerations, average metabolic power, explosive distance, and high metabolic power distance (>25.5 W·kg). Mixed-effect linear models revealed significant effects for CK and CMJ Z-score on total high-speed distance, very high-speed distance, accelerations, decelerations, explosive distance, and maximal velocity. Effects are reported with 90% confidence limits. A CK Z-score of +1 corresponded to a -5.5 ± 1.1, -3.9 ± 0.5, -4.3 ± 2.9%, -4.1 ± 2.9%, -3.1 ± 2.9%, and -4.6 ± 1.9%, reduction in total high-speed distance, very high-speed distance, accelerations, decelerations, explosive distance, and maximal velocity, respectively. Countermovement jump Z-score of -1 corresponded to a -3.5 ± 1.1, -2.9 ± 0.5, -2.1 ± 1.4, -5.3 ± 2.9%, -3.8 ± 2.9%, -1.1 ± 2.9%, and -5.6 ± 1.2% reduction in these external load measures. Magnitude-based analysis revealed that the practical size of the effect of a pretraining CMJ Z-score of -1 and CK Z-score of +1 would have on total high-speed distance, very high-speed distance, high metabolic power distance (>25.5 W·kg), accelerations, decelerations, explosive distance, and maximal velocity was likely negative. The results of this study suggest that systematic pretraining monitoring of neuromuscular and muscle stress within soccer cohorts can provide coaches with information about the training output that can be expected from individual players during a training session.


Assuntos
Desempenho Atlético/fisiologia , Creatina Quinase/sangue , Corrida/fisiologia , Futebol/fisiologia , Aceleração , Adulto , Desaceleração , Humanos , Modelos Lineares , Masculino , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Estudos Prospectivos , Adulto Jovem
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