ABSTRACT
Knowledge of magnetic symmetry is vital for exploiting nontrivial surface states of magnetic topological materials. EuIn2As2 is an excellent example, as it is predicted to have collinear antiferromagnetic order where the magnetic moment direction determines either a topological-crystalline-insulator phase supporting axion electrodynamics or a higher-order-topological-insulator phase with chiral hinge states. Here, we use neutron diffraction, symmetry analysis, and density functional theory results to demonstrate that EuIn2As2 actually exhibits low-symmetry helical antiferromagnetic order which makes it a stoichiometric magnetic topological-crystalline axion insulator protected by the combination of a 180∘ rotation and time-reversal symmetries: [Formula: see text]. Surfaces protected by [Formula: see text] are expected to have an exotic gapless Dirac cone which is unpinned to specific crystal momenta. All other surfaces have gapped Dirac cones and exhibit half-integer quantum anomalous Hall conductivity. We predict that the direction of a modest applied magnetic field of µ0H ≈ 1 to 2 T can tune between gapless and gapped surface states.
ABSTRACT
Objective: Minimal risk weight loss tools are needed. This study's objective was to confirm Food and Drug Administration submissions of the SmartByte™ System's safety and efficacy. Methods: This 16-week, prospective, single-arm, four-centre, observational study assessed the oral device in combination with a video-delivered lifestyle programme in adults aged 18-49 years with body mass index 27 to <35 kg m-2. Results: Seventy-six subjects received the device and video lifestyle instruction. The prespecified per protocol (PP) population (N = 40) required sensor-verified use of the device ≥7 times per week for 14 of 16 weeks, overall device usage rate of ≥33% and study completion. At week 16, 12 (30%) achieved ≥5% weight loss, 16 (40%) achieved ≥4% and 21 (52.5%) achieved ≥3%. Week 16 mean loss for the PP population was 2.93%, and among 36 participants who did not meet PP criteria, it was 1.45%. Among 76 intent-to-treat subjects, two subjects reported three mild to moderate device-related adverse events, resolving spontaneously (one hard palate abrasion and two tongue lacerations). Conclusion: The System, a minimal risk tool, can help individuals achieve meaningful weight loss, when used with a lifestyle video. More frequent device use was associated with more weight loss, on average, and greater chance of achieving ≥4% or ≥5% weight loss.
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We have determined the magnetic structures of GdCuSn, GdAgSn and GdAuSn using a combination of [Formula: see text]Gd Mössbauer spectroscopy and neutron powder diffraction. Each compound shows the same antiferromagnetic ordering of the Gd sublattice. The magnetic cell is doubled along the crystallographic a-axis (propagation vector [Formula: see text]) with the moments aligned along the hexagonal c-axis, forming alternating ferromagnetic sheets of up/down Gd moments along the a-axis.
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Polycrystalline samples of Ln2CoGe4O12 (Ln = Gd, Tb, Dy, Ho or Er) and LnBCoGe4O12 (B = Sc or Lu) have been prepared and characterised by a combination of magnetometry, 155Gd Mössbauer spectroscopy and, in the case of Tb2CoGe4O12 and TbScCoGe4O12, neutron diffraction. The holmium- and erbium-containing compositions remain paramagnetic down to 2 K, those containing dysprosium behave as spin glasses and the terbium and gadolinium-containing compounds show long-range magnetic order with transition temperatures below 4 K in all cases. The data can be rationalized qualitatively in terms of the interplay between magnetic anisotropy and crystal field effects.
ABSTRACT
Neutron powder diffraction patterns measured above T C have been used to determine the location of the excess Mn in MnxGa (1.15 ≤ x ≤ 1.8). This information has then been used to constrain the fits to neutron powder diffraction patterns measured at ambient temperature and so determine unambiguously the Mn moments in this system. We find that Mn randomly occupies the two Ga sites (2a and 2b) in the I4/mmm structure and propose that it is more appropriate to use a simpler structure based on the P4/mmm space group with a reduced unit cell. In this structure the two Ga sites are formally equivalent (they occupy the 1a site while Mn occupies the 1d site). Our experimental observations are supported by DFT calculations. Below T C we find that the Mn(1d) moment is constant at 2.45(3) µ B , while Mn on the 1a site carries a slightly larger moment (~3 µ B ) that is coupled antiparallel to the Mn(1d) moments, leading to the observed drop in magnetisation with increasing Mn content in MnxGa.
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To assess the association of markers for dietary protein intake, measures of dietary adherence and demographic variables with weight loss in the POUNDS Lost study over the first 6 months and again between 6 and 24 months using data from those who completed each period. This is a secondary analysis of pooled data on completers assigned to one of four diets: 65%C/15%P/20%F (AP/LF), 55%C/25%P/20%F (HP/LF), 45%C/15%P/40%F (AP/HF) or 35%C/25%P40%F (HP/HF) in the POUNDS Lost study. Urinary nitrogen excretion, dietary adherence measured by 24-h recall and attendance at sessions, age (above and below 50 years), gender, race/ethnicity and activity by pedometry were analysed. Increased spread between protein intake at baseline and protein at 6 or 24 months, assessed by urinary nitrogen excretion, was associated with greater weight loss from baseline to 2 years. At 6 and 24 months, older age, male gender, body mass index > 30 kg m-2 and adherence to the fat and protein diets were associated with more weight loss. None of these variables was associated with a regain from 6 to 24 months. Weight regain for women in the highest carbohydrate (65%) group was significantly greater (-4.4 kg [95% CI: -5.9, -3.0]) than for women in the lowest carbohydrate group (-1.8 kg [95% CI: -3.2, -0.4 kg]) (P for interaction = 0.012). An increased spread in the difference between baseline and follow-up protein intake was associated with greater weight loss, consistent with the 'protein spread theory'. Women eating the highest carbohydrate diet regained more weight from 6 to 24 months.
Subject(s)
Dietary Proteins/metabolism , Obesity/diet therapy , Adult , Aged , Biomarkers/metabolism , Body Mass Index , Dietary Fats/analysis , Dietary Fats/metabolism , Dietary Proteins/analysis , Female , Humans , Middle Aged , Obesity/metabolism , Obesity/physiopathology , Obesity/psychology , Patient Compliance , Weight LossABSTRACT
(151)Eu Mössbauer spectroscopy and neutron powder diffraction are combined to show that the tetragonal (I4mm #107) compound EuNiGe3 orders magnetically below [Formula: see text] K and adopts a complex incommensurate helicoidal magnetic structure at 3.6 K, with a propagation vector [Formula: see text] and a Eu moment of 7.1(2) [Formula: see text]. On warming through 6 K an incommensurate sinusoidal modulation develops and dominates the magnetic order by 12 K.
ABSTRACT
The antiferromagnetic structures of both the manganese and europium sublattices in EuMn2Ge2 have been determined using thermal neutron diffraction. T(N)(Mn) = 714(5) K with the 3.35(5) µ(B) (at 285 K) Mn moments ordering according to the I4'/m'm'm space group. The Eu order is incommensurate with the 6.1(2) µ(B) (at 3.6 K) Eu moments oriented parallel to the c-axis with a propagation vector of k = [0.153(2) 0 0]. Both neutron diffraction and (151)Eu Mössbauer spectroscopy reveal evidence of magnetic short-range ordering of the Eu sublattice around and above T(N)(Eu) â¼ 10 K. The ordering temperature of the Eu sublattice is strongly affected by the sample's thermal history and rapid quenching from the melting point may lead to a complete suppression of that ordering.
ABSTRACT
Magnetization measurements have been carried out on a series of carefully prepared single-phase Mn(1+x)Ga (0
ABSTRACT
Antiferromagnetic ordering of EuCu2Sb2 which forms in the tetragonal CaBe2Ge2-type structure (space group P4/nmm #129) has been studied using neutron powder diffraction and (151)Eu Mössbauer spectroscopy. The room temperature (151)Eu isomer shift of -12.8(1) mm s(-1) shows the Eu to be divalent, while the (151)Eu hyperfine magnetic field (B(hf)) reaches 28.7(2) T at 2.1 K, indicating a full Eu(2+) magnetic moment. B(hf)(T) follows a smooth S = 7/2 Brillouin function and yields an ordering temperature of 5.1(1) K. Refinement of the neutron diffraction data reveals a collinear A-type antiferromagnetic arrangement with the Eu moments perpendicular to the tetragonal c-axis. The refined Eu magnetic moment at 0.4 K is 7.08(15) µ(B) which is the full free-ion moment expected for the Eu(2+) ion with S = 7/2 and a spectroscopic splitting factor of g = 2.
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We have determined the magnetic structure of the intermetallic compound Gd2Fe2Si2C using neutron powder diffraction, (155)Gd and (57)Fe Mössbauer spectroscopy. This compound crystallizes in a monoclinic (C2/m) structure and its magnetic structure is characterized by antiferromagnetic order of the Gd sublattice along the b-axis, with cell-doubling along the c-axis. The propagation vector is k = [0 0 ½]. At 3.6 K the Gd moment reaches 6.2(2) µ(B). Finally, (57)Fe Mössbauer spectroscopy shows no evidence of magnetic ordering of the Fe sublattice.
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OBJECTIVE: To formulate clinical practice guidelines for the pharmacological management of obesity. PARTICIPANTS: An Endocrine Society-appointed Task Force of experts, a methodologist, and a medical writer. This guideline was co-sponsored by the European Society of Endocrinology and The Obesity Society. EVIDENCE: This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to describe the strength of recommendations and the quality of evidence. CONSENSUS PROCESS: One group meeting, several conference calls, and e-mail communications enabled consensus. Committees and members of the Endocrine Society, the European Society of Endocrinology, and The Obesity Society reviewed and commented on preliminary drafts of these guidelines. Two systematic reviews were conducted to summarize some of the supporting evidence. CONCLUSIONS: Weight loss is a pathway to health improvement for patients with obesity-associated risk factors and comorbidities. Medications approved for chronic weight management can be useful adjuncts to lifestyle change for patients who have been unsuccessful with diet and exercise alone. Many medications commonly prescribed for diabetes, depression, and other chronic diseases have weight effects, either to promote weight gain or produce weight loss. Knowledgeable prescribing of medications, choosing whenever possible those with favorable weight profiles, can aid in the prevention and management of obesity and thus improve health.(AU)
Subject(s)
Humans , Depression/etiology , Diabetes Mellitus/etiology , Obesity/drug therapy , Phentermine/therapeutic use , Dopamine Agents/therapeutic use , Norepinephrine/therapeutic use , Bupropion/therapeutic use , Serotonin Agents/therapeutic use , Glucagon-Like Peptide 1/agonists , Naltrexone/therapeutic useABSTRACT
AIM: To investigate the race-specific trend in attainment of the American Diabetes Association cardiovascular risk factor control goals (HbA1c <53 mmol/mol (7.0%), blood pressure <130/80 mmHg and LDL cholesterol <2.6mmol/l) by patients with Type 2 diabetes. METHODS: The study sample included 14 946 African-American and 12 758 white patients who were newly diagnosed with Type 2 diabetes between 2001 and 2009 in the Louisiana State University Hospital system. The race-specific percentages of patients' attainment of American Diabetes Association goals were calculated using the baseline and follow-up measurements of HbA1c , blood pressure, and LDL cholesterol levels. Logistic regression was used to test the difference between African-American and white patients. RESULTS: The percentage of patients who met all three American Diabetes Association goals increased from 8.2% in 2001 to 10.2% in 2009 (increased by 24.4%) in this cohort. Compared with African-American patients, white patients had better attainment of the following American Diabetes Association goals: HbA1c (61.4 vs. 55.1%), blood pressure (25.8 vs. 20.4%), LDL cholesterol (40.1 vs. 37.7%) and all three goals (7.3 vs. 5.1%). African-American and white patients generally had a better cardiovascular disease risk factor profile during follow-up when we assessed attainment of the American Diabetes Association goals by means of HbA1c , blood pressure and LDL cholesterol. CONCLUSIONS: During 2001-2009, the present low-income cohort of people with Type 2 diabetes generally experienced improved control of cardiovascular disease risk factors. White patients had better attainment of the American Diabetes Association cardiovascular risk factor control goals than their African-American counterparts.
Subject(s)
Cardiovascular Diseases/prevention & control , Diabetes Mellitus, Type 2/therapy , Diabetic Angiopathies/prevention & control , Diabetic Cardiomyopathies/prevention & control , Healthcare Disparities , Medically Uninsured , Adult , Black or African American , Aged , Cardiovascular Diseases/complications , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/ethnology , Cohort Studies , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/economics , Diabetes Mellitus, Type 2/ethnology , Diabetic Angiopathies/economics , Diabetic Angiopathies/epidemiology , Diabetic Angiopathies/ethnology , Diabetic Cardiomyopathies/economics , Diabetic Cardiomyopathies/epidemiology , Diabetic Cardiomyopathies/ethnology , Female , Healthcare Disparities/economics , Healthcare Disparities/ethnology , Hospitals, State , Hospitals, University , Humans , Longitudinal Studies , Louisiana/epidemiology , Male , Medically Uninsured/ethnology , Middle Aged , Prospective Studies , Risk Factors , Sex Factors , White PeopleABSTRACT
The a-FexHf100-x system is used to explore the application of TDPAC (the time differential perturbed γ-γ angular correlation technique) to non-trivial anisotropic magnetic relaxation. The effect of fluctuations in this system is primarily to cause a decay of the zero-frequency component, which is characterized by the phenomenological decay rate λ. The zero-field magnetic phase diagram, constructed from both static and dynamic features of the data, and the temperature dependence of λ are both fully consistent with the physics of partial bond frustration. The results demonstrate that the magnetic fluctuations are meaningfully characterized by simple spectrum features, and are not obscured by large static fields or severe disorder.
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The effects of iron substitution on the structural and magnetic properties of the GdCo(12-x)Fe(x)B6 (0 ≤ x ≤ 3) series of compounds have been studied. All of the compounds form in the rhombohedral SrNi12B6-type structure and exhibit ferrimagnetic behaviour below room temperature: T(C) decreases from 158 K for x = 0 to 93 K for x = 3. (155)Gd Mössbauer spectroscopy indicates that the easy magnetization axis changes from axial to basal-plane upon substitution of Fe for Co. This observation has been confirmed using neutron powder diffraction. The axial to basal-plane transition is remarkably sensitive to the Fe content and comparison with earlier (57)Fe-doping studies suggests that the boundary lies below x = 0.1.
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Few well-controlled trials have evaluated the effects that macronutrient composition has on changes in food cravings during weight loss treatment. The present study, which was part of the Preventing Overweight Using Novel Dietary Strategies (POUNDS LOST) trial, investigated whether the fat and protein content of four different diets affected changes in specific food cravings in overweight and obese adults. A sample of 811 adults were recruited across two clinical sites, and each participant was randomly assigned to one of four macronutrient prescriptions: 1) low fat (20% of energy), average protein (15% of energy); 2) moderate fat (40%), average protein (15%); 3) low fat (20%), high protein (25%); 4) moderate fat (40%), high protein (25%). With few exceptions, the type of diet that participants were assigned did not differentially affect changes in specific food cravings. Participants assigned to the high-fat diets, however, had reduced cravings for carbohydrates at month 12 (p<0.05) and fruits and vegetables at month 24. Also, participants assigned to high-protein diets had increased cravings for sweets at month 6 and month 12 (ps<0.05). Participants in all four dietary conditions reported significant reductions in food cravings for specific types of foods (i.e., high fat foods, fast food fats, sweets, and carbohydrates/starches; all ps<0.05). Cravings for fruits and vegetables, however, were increased at month 24 (p<0.05). Calorically restricted diets (regardless of their macronutrient composition) yielded significant reductions in cravings for fats, sweets, and starches whereas cravings for fruits and vegetables were increased.
Subject(s)
Caloric Restriction , Diet, Reducing , Dietary Carbohydrates/administration & dosage , Dietary Fats/administration & dosage , Food Preferences , Overweight/diet therapy , Weight Loss , Adult , Age Factors , Aged , Biomarkers/blood , Body Mass Index , Dietary Proteins/administration & dosage , Feeding Behavior , Female , Follow-Up Studies , Humans , Male , Middle Aged , Obesity/diet therapy , Self Report , Sex Factors , Surveys and Questionnaires , Treatment OutcomeABSTRACT
The TiNiSi-type structure, antiferromagnetic ordering and divalent state of europium in EuPdSn have been confirmed by neutron powder diffraction. The Néel temperature is 16.2(3) K. The magnetic diffraction peaks can be indexed with a propagation vector k = [0, 0.217, q(z)] (q(z) ≤ 0.02) at 13.2 K, and k = [0, 0.276, 0] at 3.6 K, indicating an incommensurate antiferromagnetic structure at both temperatures. At 13.2 K, the best refinement is obtained with a sinusoidally modulated magnetic structure and europium magnetic moments oriented in the (a,b) plane with an azimuthal angle Ï of 66(4)°relative to the a-axis. By 3.6 K, the magnetic structure of EuPdSn has transformed to an (a,b) planar helimagnetic structure (a 'flat spiral').
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BACKGROUND: Weight loss reduces energy expenditure, but the contribution of different macronutrients to this change is unclear. HYPOTHESIS: We tested the hypothesis that macronutrient composition of the diet might affect the partitioning of energy expenditure during weight loss. DESIGN: A substudy of 99 participants from the Preventing Overweight Using Novel Dietary Strategies (POUNDS LOST) trial had total energy expenditure (TEE) measured by doubly labeled water, and resting energy expenditure (REE) measured by indirect calorimetry at baseline and repeated at 6 months in 89 participants. Participants were randomly assigned to one of four diets with either 15 or 25% protein and 20 or 40% fat. RESULTS: TEE and REE were positively correlated with each other and with fat-free mass and body fat, at baseline and 6 months. The average weight loss of 8.1 ± 0.65 kg (least-square mean ± s.e.) reduced TEE by 120 ± 56 kcal per day and REE by 136 ± 18 kcal per day. A greater weight loss at 6 months was associated with a greater decrease in TEE and REE. Participants eating the high-fat diet (HF) lost significantly more fat-free mass (1.52 ± 0.55 kg) than the low-fat (LF) diet group (P<0.05). Participants eating the LF diet had significantly higher measures of physical activity than the HF group. CONCLUSION: A greater weight loss was associated with a larger decrease in both TEE and REE. The LF diet was associated with significant changes in fat-free body mass and energy expenditure from physical activity compared with the HF diet.
Subject(s)
Diet, Fat-Restricted , Diet, High-Fat , Energy Metabolism , Obesity/diet therapy , Adult , Aged , Body Fat Distribution , Female , Humans , Los Angeles/epidemiology , Male , Massachusetts/epidemiology , Middle Aged , Obesity/epidemiology , Obesity/physiopathology , Rest , Weight LossABSTRACT
GdAgSb(2) has been studied using (155)Gd Mössbauer spectroscopy and neutron powder diffraction at a wavelength of 2.3672(1) Å. Commensurate antiferromagnetic order develops below T(N) = 13.8(4) K with the 6.2(3) µ(B) Gd moments lying in the ab-plane of the tetragonal cell. The magnetic ordering is characterized by a [½ 0 0] propagation vector (i.e. the magnetic cell is doubled along one of the crystallographic basal plane axes) with the Gd moments oriented perpendicular to the doubled direction. These results are fully consistent with an earlier determination by x-ray resonant magnetic exchange scattering.