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1.
Tech Coloproctol ; 28(1): 145, 2024 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-39480607

RESUMEN

BACKGROUND: The International Anorectal Physiology Working Group (IAPWG) suggests a standardized protocol to perform high-resolution anorectal manometry. The applicability and possible limitations of the IAPWG protocol in performing three-dimensional high-definition anorectal manometry (3D-ARM) have still to be extensively evaluated. METHODS: The IAPWG protocol was applied in performing 3D-ARM. Anorectal manometry (ARM) and a balloon expulsion test (BET) were performed according to IAPGW protocol in 290 patients. KEY RESULTS: A total of 84 males and 206 females (mean age 57.1 ± 15.7 years) were enrolled in six Italian centers. The reasons for which the patients were sent to perform 3D-ARM were: constipation (53.1%), fecal incontinence (26.9%), anal pain (3.1%), postsurgical (3.8%) and presurgical evaluation (4.8%), prolapse (3.4%), anal fissure (2.8%), and other (2.1%). Due to organic and functional conditions (low rectal anterior resections, rectal prolapses, and J-pouch after colectomy), we were unable to perform a complete 3D-ARM on six patients. Overall, a complete 3D-ARM and BET following IAPWG protocol was carried out in 284 patients (97.9%). The following were recorded: rest pressure (81.9 ± 32.0 mmHg) and length of the anal sphincter (37.0 ± 6.2 cm), maximum anal squeeze pressure (201.6 ± 81.3 mmHg), squeeze duration (22.0 ± 8.8 s), maximum rectal (48.7 ± 41.0 mmHg) and minimum anal pressure (73.3 ± 36.5 mmHg) during push, presence/absence of a dyssynergic pattern, cough reflex and rectal sensations (first constant sensation 48.4 ± 29.5 mL, desire to defecate 83.7 ± 52.1 mL, and maximum tolerated volume 149.5 ± 72.6 mL), and presence/absence of rectoanal inhibitory reflex. Mean 3D-ARM registration time was 14 min 7 s ± 3 min 12 s. CONCLUSIONS: This is the first multicentric study that evaluates the applicability of the IAPWG protocol in 3D-ARM performed in different manometric laboratories (both gastroenterological and surgical). The IAPWG protocol was easy to perform and was not time consuming. A diagnosis according to the London Classification was easily obtained in most patients in which 3D-ARM was carried out. No clear limitations to the applicability of the IAPWG protocol were detected.


Asunto(s)
Canal Anal , Estudios de Factibilidad , Manometría , Recto , Humanos , Manometría/métodos , Masculino , Persona de Mediana Edad , Femenino , Italia , Estudios Prospectivos , Canal Anal/fisiopatología , Anciano , Adulto , Imagenología Tridimensional/métodos , Enfermedades del Recto/cirugía , Enfermedades del Recto/fisiopatología , Protocolos Clínicos
2.
Phys Rev Lett ; 129(20): 207201, 2022 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-36461990

RESUMEN

Spinons are well known as the elementary excitations of one-dimensional antiferromagnetic chains, but means to realize spinons in higher dimensions is the subject of intense research. Here, we use resonant x-ray scattering to study the layered trimer iridate Ba_{4}Ir_{3}O_{10}, which shows no magnetic order down to 0.2 K. An emergent one-dimensional spinon continuum is observed that can be well described by XXZ spin-1/2 chains with a magnetic exchange of ∼55 meV and a small Ising-like anisotropy. With 2% isovalent Sr doping, magnetic order appears below T_{N}=130 K along with sharper excitations in (Ba_{1-x}Sr_{x})_{4}Ir_{3}O_{10}. Combining our data with exact diagonalization calculations, we find that the frustrated intratrimer interactions effectively reduce the system into decoupled spin chains, the subtle balance of which can be easily tipped by perturbations such as chemical doping. Our results put Ba_{4}Ir_{3}O_{10} between the one-dimensional chain and two-dimensional quantum spin liquid scenarios, illustrating a new way to suppress magnetic order and realize fractional spinons.

3.
Phys Rev Lett ; 122(10): 106401, 2019 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-30932648

RESUMEN

The electronic states of many Mott insulators, including iridates, are often conceptualized in terms of localized atomic states such as the famous "J_{eff}=1/2 state." Although orbital hybridization can strongly modify such states and dramatically change the electronic properties of materials, probing this process is highly challenging. In this Letter, we directly detect and quantify the formation of dimer orbitals in an iridate material Ba_{5}AlIr_{2}O_{11} using resonant inelastic x-ray scattering. Sharp peaks corresponding to the excitations of dimer orbitals are observed and analyzed by a combination of density functional theory calculations and theoretical simulations based on an Ir-Ir cluster model. Such partially delocalized dimer states lead to a redefinition of the angular momentum of the electrons and changes in the magnetic and electronic behaviors of the material. We use this to explain the reduction of the observed magnetic moment with respect to predictions based on atomic states. This study opens new directions to study dimerization in a large family of materials, including solids, heterostructures, molecules, and transient states.

4.
J Endocrinol Invest ; 41(5): 583-590, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29090431

RESUMEN

PURPOSE: To evaluate the efficacy of alpha-lipoic acid (ALA) administration on hormonal and metabolic parameters of obese PCOS patients. METHODS: A group of 32 obese PCOS patients were selected after informed consent. 20 patients referred to have first grade relatives with diabetes type I or II. Hormonal and metabolic parameters as well as OGTT were evaluated before and after 12 weeks of ALA integrative administration (400 mg per os every day). RESULTS: ALA administration significantly decreased insulin, glucose, BMI and HOMA index. Hyperinsulinemia and insulin response to OGTT decreased both as maximal response (Δmax) and as AUC. PCOS with diabetes relatives showed the decrease also of triglyceride and GOT. Interestingly in all PCOS no changes occurred on all hormonal parameters involved in reproduction such as LH, FSH, and androstenedione. CONCLUSIONS: ALA integrative administration at a low dosage as 400 mg daily improved the metabolic impairment of all PCOS patients especially in those PCOS with familiar diabetes who have a higher grade of risk of NAFLD and predisposition to diabetes.


Asunto(s)
Antioxidantes/administración & dosificación , Diabetes Mellitus/tratamiento farmacológico , Resistencia a la Insulina , Obesidad/tratamiento farmacológico , Síndrome del Ovario Poliquístico/tratamiento farmacológico , Ácido Tióctico/administración & dosificación , Adulto , Índice de Masa Corporal , Diabetes Mellitus/patología , Femenino , Estudios de Seguimiento , Humanos , Obesidad/complicaciones , Obesidad/patología , Síndrome del Ovario Poliquístico/complicaciones , Síndrome del Ovario Poliquístico/patología , Pronóstico , Adulto Joven
5.
Exp Parasitol ; 192: 12-18, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30026113

RESUMEN

Cutaneous leishmaniasis is the most common form of leishmaniasis and the available chemotherapy causes serious side effects, justifying the search for new therapies. This study investigated the antileishmanial activity of bovine serum albumin (BSA) nanoparticles containing amphotericin B (AmB) against Leishmania amazonensis. The antiproliferative activity against promastigotes and amastigotes was assessed and the cytotoxicity was determined and compared to commercial AmB-deoxycholate (AmB-D). In vivo antileishmania activity was evaluated in murine cutaneous leishmaniasis model. BSA nanoparticles showed spherical shape, mean size about 180 nm, zeta potential of ≈ -45 mV and AmB encapsulation efficiency >95%. AmB-D was effective in promastigote and amastigote forms, while AmB-loaded BSA nanoparticles were more effective against amastigotes than promastigotes. AmB-D was more effective than AmB-loaded BSA nanoparticles in both forms, however, the lowest cytotoxicity against macrophages was achieved by AmB-nanoparticles. BALB/c mice treated with AmB-D or AmB-loaded BSA nanoparticles showed a significant decrease in the lesion thickness at the infected footpad. Histopathological analysis after 3 weeks of treatment revealed AmB-D-related toxicity in heart, spleen, lung, liver and kidneys, while treatment with AmB-loaded BSA nanoparticles did not reveal tissue toxicity. The antileishmanial efficacy and the reduced toxicity become BSA nanoparticles containing AmB a potential candidate for treating cutaneous leishmaniasis.


Asunto(s)
Anfotericina B/administración & dosificación , Antiprotozoarios/administración & dosificación , Leishmania mexicana/efectos de los fármacos , Leishmaniasis Cutánea/tratamiento farmacológico , Nanopartículas/uso terapéutico , Albúmina Sérica Bovina , Análisis de Varianza , Animales , Línea Celular , Portadores de Fármacos , Concentración 50 Inhibidora , Riñón/patología , Hígado/patología , Pulmón/patología , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/parasitología , Masculino , Ratones , Ratones Endogámicos BALB C , Microscopía Electrónica de Transmisión , Miocardio/patología , Nanopartículas/ultraestructura , Tamaño de la Partícula , Bazo/patología
6.
Nat Mater ; 15(6): 601-5, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27159018

RESUMEN

Measuring how the magnetic correlations evolve in doped Mott insulators has greatly improved our understanding of the pseudogap, non-Fermi liquids and high-temperature superconductivity. Recently, photo-excitation has been used to induce similarly exotic states transiently. However, the lack of available probes of magnetic correlations in the time domain hinders our understanding of these photo-induced states and how they could be controlled. Here, we implement magnetic resonant inelastic X-ray scattering at a free-electron laser to directly determine the magnetic dynamics after photo-doping the Mott insulator Sr2IrO4. We find that the non-equilibrium state, 2 ps after the excitation, exhibits strongly suppressed long-range magnetic order, but hosts photo-carriers that induce strong, non-thermal magnetic correlations. These two-dimensional (2D) in-plane Néel correlations recover within a few picoseconds, whereas the three-dimensional (3D) long-range magnetic order restores on a fluence-dependent timescale of a few hundred picoseconds. The marked difference in these two timescales implies that the dimensionality of magnetic correlations is vital for our understanding of ultrafast magnetic dynamics.


Asunto(s)
Iridio/química , Campos Magnéticos , Simulación de Dinámica Molecular , Estroncio/química , Superconductividad
7.
Phys Rev Lett ; 118(2): 027202, 2017 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-28128620

RESUMEN

We use resonant elastic and inelastic x-ray scattering at the Ir-L_{3} edge to study the doping-dependent magnetic order, magnetic excitations, and spin-orbit excitons in the electron-doped bilayer iridate (Sr_{1-x}La_{x})_{3}Ir_{2}O_{7} (0≤x≤0.065). With increasing doping x, the three-dimensional long range antiferromagnetic order is gradually suppressed and evolves into a three-dimensional short range order across the insulator-to-metal transition from x=0 to 0.05, followed by a transition to two-dimensional short range order between x=0.05 and 0.065. Because of the interactions between the J_{eff}=1/2 pseudospins and the emergent itinerant electrons, magnetic excitations undergo damping, anisotropic softening, and gap collapse, accompanied by weakly doping-dependent spin-orbit excitons. Therefore, we conclude that electron doping suppresses the magnetic anisotropy and interlayer couplings and drives (Sr_{1-x}La_{x})_{3}Ir_{2}O_{7} into a correlated metallic state with two-dimensional short range antiferromagnetic order. Strong antiferromagnetic fluctuations of the J_{eff}=1/2 moments persist deep in this correlated metallic state, with the magnon gap strongly suppressed.

8.
Scand J Med Sci Sports ; 27(1): 66-74, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26643874

RESUMEN

Stress-inducible Hsp72 is a potential biomarker to track risk of exertional heat illness during exercise/environmental stress. Characterization of extracellular (eHsp72) vs cellular Hsp72 (iHsp72) responses is required to define the appropriate use of Hsp72 as a reliable biomarker. In each of four repeat visits, participants (n = 6 men, 4 trials; total n = 24): (a) passively dehydrated overnight, (b) exercised (2 h) with no fluid in a hot, humid environmental chamber, (c) rested and rehydrated (1 h), (d) maximally exercised for 0.5 h, and (e) returned after 24 h of at-home recovery and rehydration. We measured rectal temperature, hydration status (% body mass loss, urine markers, serum osmolality), and Hsp72 (ELISA, flow cytometry. eHsp72 (circulating) and iHsp72 (CD3+ PBMCs) correlated (P < 0.05) with markers of heat, exercise, and dehydration stresses. eHsp72 immediately post-exercise (>15% above baseline, P < 0.05) decreased back to baseline levels by 1 h post-exercise, but iHsp72 expression continued to rise and remained elevated 24 h post-exercise (~2.5-fold baseline, P < 0.05). These data suggest that in addition to the classic physiological biomarkers of exercise heat stress, using cellular Hsp72 as an indicator of lasting effects of stress into recovery may be most appropriate for determining long-term effects of stress on risk for exertional heat illness.


Asunto(s)
Temperatura Corporal , Deshidratación/metabolismo , Ejercicio Físico/fisiología , Proteínas del Choque Térmico HSP72/metabolismo , Trastornos de Estrés por Calor/metabolismo , Calor , Humedad , Estrés Fisiológico/fisiología , Adulto , Biomarcadores/metabolismo , Espacio Extracelular/metabolismo , Humanos , Masculino , Concentración Osmolar , Distribución Aleatoria , Adulto Joven
9.
Phys Rev Lett ; 114(12): 126401, 2015 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-25860761

RESUMEN

We combine resonant inelastic x-ray scattering and model calculations in the Kondo lattice compound YbInCu_{4}, a system characterized by a dramatic increase in Kondo temperature and associated valence fluctuations below a first-order valence transition at T≃42 K. The bulk-sensitive, element-specific, and valence-projected charge excitation spectra reveal an unusual quasigap in the Yb-derived state density which drives an instability of the electronic structure and renormalizes the low-energy effective Hamiltonian at the transition. Our results provide long-sought experimental evidence for a link between temperature-driven changes in the low-energy Kondo scale and the higher-energy electronic structure of this system.

10.
Scand J Med Sci Sports ; 25 Suppl 1: 229-39, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25943674

RESUMEN

Immediate treatment with cold water immersion (CWI) is the gold standard for exertional heatstroke. In the field, however, treatment is often delayed due to delayed paramedic response and/or inaccurate diagnosis. We examined the effect of treatment (reduction of rectal temperature to 37.5 °C) delays of 5, 20, and 40 min on core cooling rates in eight exertionally heat-stressed (40.0 °C rectal temperature) individuals. We found that rectal temperature was elevated above baseline (P < 0.05) at the end of all delay periods (5 min: 40.08 ± 0.32; 20 min: 39.92 ± 0.40; 40 min: 39.57 ± 0.29 °C). Mean arterial pressure was reduced (P < 0.05) below baseline (92 ± 1.8 mm Hg) after all delay periods (5 min: 75 ± 2.6; 20 min: 74 ± 1.7; 40 min: 70 ± 2.1 mm Hg; P > 0.05). Rectal core cooling rates were similar among conditions (5 min: 0.20 ± 0.01; 20 min: 0.17 ± 0.02; 40 min: 0.17 ± 0.01 °C/min; P > 0.05). The rectal temperature afterdrop following CWI was similar across conditions (5 min: 35.95; 20 min: 35.61; 40 min: 35.87 °C; P > 0.05). We conclude that the effectiveness of 2 °C CWI as a treatment for exertional heat stress remains high even when applied with a delay of 40 min. Therefore, our results support that CWI is the most appropriate treatment for exertional heatstroke as it is capable of quickly reversing hyperthermia even when treatment is commenced with a significant delay.


Asunto(s)
Crioterapia/métodos , Ejercicio Físico/fisiología , Fiebre/terapia , Trastornos de Estrés por Calor/terapia , Calor/efectos adversos , Inmersión , Agua , Adulto , Temperatura Corporal/fisiología , Fiebre/etiología , Fiebre/fisiopatología , Trastornos de Estrés por Calor/etiología , Trastornos de Estrés por Calor/fisiopatología , Humanos , Masculino , Esfuerzo Físico/fisiología , Factores de Tiempo , Resultado del Tratamiento
11.
Phys Rev Lett ; 112(14): 147201, 2014 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-24766006

RESUMEN

We report x-ray resonant magnetic scattering and resonant inelastic x-ray scattering studies of epitaxially strained Sr2IrO4 thin films. The films were grown on SrTiO3 and (LaAlO3)0.3(Sr2AlTaO6)0.7 substrates, under slight tensile and compressive strains, respectively. Although the films develop a magnetic structure reminiscent of bulk Sr2IrO4, the magnetic correlations are extremely anisotropic, with in-plane correlation lengths significantly longer than the out-of-plane correlation lengths. In addition, the compressive (tensile) strain serves to suppress (enhance) the magnetic ordering temperature TN, while raising (lowering) the energy of the zone-boundary magnon. Quantum chemical calculations show that the tuning of magnetic energy scales can be understood in terms of strain-induced changes in bond lengths.

12.
Phys Rev Lett ; 110(4): 047003, 2013 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-25166195

RESUMEN

We report an Fe Kß x-ray emission spectroscopy study of local magnetic moments in the rare-earth doped iron pnictide Ca(1-x)RE(x)Fe(2)As(2) (RE = La, Pr, and Nd). In all samples studied the size of the Fe local moment is found to decrease significantly with temperature and goes from ∼ 0.9 µ(B) at T = 300 K to ∼ 0.45 µ(B) at T = 70 K. In the collapsed tetragonal phase of Nd- and Pr-doped samples (T<70 K) the local moment is quenched, while the moment remains unchanged for the La-doped sample, which does not show lattice collapse. Our results show that Ca(1-x)RE(x)Fe(2)As(2) (RE = Pr and Nd) exhibits a spin-state transition and provide direct evidence for a nonmagnetic Fe(2+) ion in the collapsed tetragonal phase; spin state as predicted by Yildirim. We argue that the gradual change of the spin state over a wide temperature range reveals the importance of multiorbital physics, in particular the competition between the crystal field split Fe 3d orbitals and the Hund's rule coupling.

13.
Phys Rev Lett ; 111(5): 057202, 2013 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-23952439

RESUMEN

We report a combined experimental and theoretical study of the unusual ferromagnetism in the one-dimensional copper-iridium oxide Sr(3)CuIrO(6). Utilizing Ir L(3) edge resonant inelastic x-ray scattering, we reveal a large gap magnetic excitation spectrum. We find that it is caused by an unusual exchange anisotropy generating mechanism, namely, strong ferromagnetic anisotropy arising from antiferromagnetic superexchange, driven by the alternating strong and weak spin-orbit coupling on the 5d Ir and 3d Cu magnetic ions, respectively. From symmetry consideration, this novel mechanism is generally present in systems with edge-sharing Cu(2+)O(4) plaquettes and Ir(4+)O(6) octahedra. Our results point to unusual magnetic behavior to be expected in mixed 3d-5d transition-metal compounds via exchange pathways that are absent in pure 3d or 5d compounds.

14.
Phys Rev Lett ; 110(7): 076402, 2013 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-25166387

RESUMEN

The electronic structure of the honeycomb lattice iridates Na(2)IrO(3) and Li(2)IrO(3) has been investigated using resonant inelastic x-ray scattering (RIXS). Crystal-field-split d-d excitations are resolved in the high-resolution RIXS spectra. In particular, the splitting due to noncubic crystal fields, derived from the splitting of j(eff)=3/2 states, is much smaller than the typical spin-orbit energy scale in iridates, validating the applicability of j(eff) physics in A(2)IrO(3). We also find excitonic enhancement of the particle-hole excitation gap around 0.4 eV, indicating that the nearest-neighbor Coulomb interaction could be large. These findings suggest that both Na(2)IrO(3) and Li(2)IrO(3) can be described as spin-orbit Mott insulators, similar to the square lattice iridate Sr(2)IrO(4).

15.
Phys Rev Lett ; 108(17): 177003, 2012 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-22680895

RESUMEN

We used resonant inelastic x-ray scattering to reveal the nature of magnetic interactions in Sr2IrO4, a 5d transition-metal oxide with a spin-orbit entangled ground state and J(eff)=1/2 magnetic moments. The magnon dispersion in Sr2IrO4 is well-described by an antiferromagnetic Heisenberg model with an effective spin one-half on a square lattice, which renders the low-energy effective physics of Sr2IrO4 much akin to that in superconducting cuprates. This point is further supported by the observation of exciton modes in Sr2IrO4, whose dispersion is strongly renormalized by magnons, which can be understood by analogy to hole propagation in the background of antiferromagnetically ordered spins in the cuprates.

16.
Phys Rev Lett ; 109(15): 157402, 2012 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-23102367

RESUMEN

Using resonant inelastic x-ray scattering, we observe in the bilayer iridate Sr3Ir2O7, a spin-orbit coupling driven magnetic insulator with a small charge gap, a magnon gap of ≈92 meV for both acoustic and optical branches. This exceptionally large magnon gap exceeds the total magnon bandwidth of ≈70 meV and implies a marked departure from the Heisenberg model, in stark contrast to the case of the single-layer iridate Sr2IrO4. Analyzing the origin of these observations, we find that the giant magnon gap results from bond-directional pseudodipolar interactions that are strongly enhanced near the metal-insulator transition boundary. This suggests that novel magnetism, such as that inspired by the Kitaev model built on the pseudodipolar interactions, may emerge in small charge-gap iridates.

17.
Phys Rev Lett ; 109(15): 157401, 2012 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-23102366

RESUMEN

The electronic structure of Sr3CuIrO6, a model system for the 5d Ir ion in an octahedral environment, is studied through a combination of resonant inelastic x-ray scattering and theoretical calculations. Resonant inelastic x-ray scattering spectra at the Ir L3 edge reveal an Ir t(2g) manifold that is split into three levels, in contrast to the expectations of the strong spin-orbit-coupling limit. Effective Hamiltonian and ab inito quantum chemistry calculations find a strikingly large noncubic crystal field splitting comparable to the spin-orbit coupling, which results in a strong mixing of the j(eff)=1/2 and j(eff)=3/2 states and modifies the isotropic wave functions on which many theoretical models are based.

18.
Nat Commun ; 13(1): 913, 2022 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-35177583

RESUMEN

Excitonic insulators are usually considered to form via the condensation of a soft charge mode of bound electron-hole pairs. This, however, presumes that the soft exciton is of spin-singlet character. Early theoretical considerations have also predicted a very distinct scenario, in which the condensation of magnetic excitons results in an antiferromagnetic excitonic insulator state. Here we report resonant inelastic x-ray scattering (RIXS) measurements of Sr3Ir2O7. By isolating the longitudinal component of the spectra, we identify a magnetic mode that is well-defined at the magnetic and structural Brillouin zone centers, but which merges with the electronic continuum in between these high symmetry points and which decays upon heating concurrent with a decrease in the material's resistivity. We show that a bilayer Hubbard model, in which electron-hole pairs are bound by exchange interactions, consistently explains all the electronic and magnetic properties of Sr3Ir2O7 indicating that this material is a realization of the long-predicted antiferromagnetic excitonic insulator phase.

19.
J Athl Train ; 2021 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-33626130

RESUMEN

CONTEXT: Exertional heat stroke (EHS) deaths can be prevented by adhering to best practices. OBJECTIVE: We investigated the adoption of policies and procedures for the recognition and treatment of EHS and the factors influencing the adoption of a comprehensive policy. DESIGN: Cross Sectional. SETTING: Online questionnaire. PATIENTS OR OTHER PARTICIPANTS: Athletic trainers (ATs) practicing in the high school (HS) setting. MAIN OUTCOME MEASURE(S): Using the NATA Position Statement: Exertional Heat Illness, an online questionnaire was developed and distributed to ATs to ascertain their schools' current written policies for the use of rectal temperature and cold-water immersion (CWI). The Precaution Adoption Process Model (PAPM), allowed for responses to be presented across the various health behavior stages ("Unaware if have the policy", "Unaware for the need for the policy", "Unengaged", "Undecided", "Decided Not to Act", "Decided to Act", "Acting", and "Maintaining"). Additional questions included perceptions of facilitators and barriers. Data are presented as proportions. RESULTS: A total of 531 ATs completed this questionnaire. Overall, 16.9% (n=62) report adoption of all components for proper recognition and treatment of EHS. The policy component with the highest adoption was "cool first transport second" with 74.1% (n=110) of ATs reporting "Acting" or "Maintaining." The most variability in the PAPM responses was for a rectal temperature policy, with 28.7% (n=103) of ATs reporting "Decided not to Act" and 20.1% (n=72) reporting "Maintaining." The most commonly reported facilitator and barrier for rectal temperature included state mandate from state HS athletics association (n=274,51.5%) and resistance or apprehension from parents or legal guardians (n=311,58.5%), respectively. CONCLUSIONS: ATs in the HS setting appear to be struggling to adopt a comprehensive EHS strategy, with rectal temperature continuing to appear as the biggest undertaking. Tailored strategies based on health behavior, facilitators and barriers may aid in changing this paradigm.

20.
Sci Rep ; 9(1): 4263, 2019 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-30862782

RESUMEN

Fundamental control of magnetic coupling through heterostructure morphology is a prerequisite for rational engineering of magnetic ground states. We report the tuning of magnetic interactions in superlattices composed of single and bilayers of SrIrO3 inter-spaced with SrTiO3 in analogy to the Ruddlesden-Popper series iridates. Magnetic scattering shows predominately c-axis antiferromagnetic orientation of the magnetic moments for the bilayer, as in Sr3Ir2O7. However, the magnetic excitation gap, measured by resonant inelastic x-ray scattering, is quite different between the two structures, evidencing a significant change in the stability of the competing magnetic phases. In contrast, the single layer iridate hosts a more bulk-like gap. We find these changes are driven by bending of the c-axis Ir-O-Ir bond, which is much weaker in the single layer, and subsequent local environment changes, evidenced through x-ray diffraction and magnetic excitation modeling. Our findings demonstrate how large changes in the magnetic interactions can be tailored and probed in spin-orbit coupled heterostructures by engineering subtle structural modulations.

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