3,612 research outputs found
Comparison between the lattice dynamics and molecular dynamics methods: Calculation results for MgSiO3 perovskite
The lattice dynamics (LD) and molecular dynamics (MD) methods have been used to calculate the structure, bulk modulus, and volume thermal expansivity of MgSiO3 perovskite, in order to investigate the reliability of the two simulation techniques over a wide range of temperature and pressure conditions. At an intermediate temperature of 500 K and zero pressure, the LD and MD values are in exellent agreement for both the structure and bulk modulus of MgSiO3 perovskite. At high temperatures and zero pressure, however, the LD method, which is based on the quasi-harmonic approximation, increasingly overestimates the molar volume of MgSiO3 perovskite because of the neglect of higher-order anharmonic terms. At the high temperatures and high pressures prevailing in the lower mantle, the errors in the LD values for both the molar volume and bulk modulus, relative to the MD values, are generally small or negligible. However, since anharmonicity decreases substantially with pressure but increases rapidly with temperature, the error in the LD simulated volume thermal expansivity is serious, especially in the lower pressure region
Temporomandibular joint prosthesis in cancer reconstruction preceding radiation therapy
Total joint prostheses are a viable treatment option after removal of malignancies invading the temporomandibular joint, even when adjuvant radiation therapy is required.publishedVersio
A multifaceted strategy using mobile technology to assist rural primary healthcare doctors and frontline health workers in cardiovascular disease risk management: protocol for the SMARTHealth India cluster randomised controlled trial
BACKGROUND: Blood Pressure related disease affected 118 million people in India in the year 2000; this figure will double by 2025. Around one in four adults in rural India have hypertension, and of those, only a minority are accessing appropriate care. Health systems in India face substantial challenges to meet these gaps in care, and innovative solutions are needed. METHODS: We hypothesise that a multifaceted intervention involving capacity strengthening of primary healthcare doctors and non-physician healthcare workers through use of a mobile device-based clinical decision support system will result in improved blood pressure control for individuals at high risk of a cardiovascular disease event when compared with usual healthcare. This intervention will be implemented as a stepped wedge, cluster randomised controlled trial in 18 primary health centres and 54 villages in rural Andhra Pradesh involving adults aged ≥40 years at high cardiovascular disease event risk (approximately 15,000 people). Cardiovascular disease event risk will be calculated based on World Health Organisation/International Society of Hypertension's region-specific risk charts. Cluster randomisation will occur at the level of the primary health centres. Outcome analyses will be conducted blinded to intervention allocation. EXPECTED OUTCOMES: The primary study outcome is the difference in the proportion of people meeting guideline-recommended blood pressure targets in the intervention period vs. the control period. Secondary outcomes include mean reduction in blood pressure levels; change in other cardiovascular disease risk factors, including body mass index, current smoking, reported healthy eating habits, and reported physical activity levels; self-reported use of blood pressure and other cardiovascular medicines; quality of life (using the EQ-5D); and cardiovascular disease events (using hospitalisation data). Trial outcomes will be accompanied by detailed process and economic evaluations. SIGNIFICANCE: The findings are likely to inform policy on a scalable strategy to overcome entrenched inequities in access to effective healthcare for under-served populations in low and middle income country settings. TRIAL REGISTRATION: Clinical Trial Registry India CTRI/2013/06/003753
Baryon Washout, Electroweak Phase Transition, and Perturbation Theory
We analyze the conventional perturbative treatment of sphaleron-induced
baryon number washout relevant for electroweak baryogenesis and show that it is
not gauge-independent due to the failure of consistently implementing the
Nielsen identities order-by-order in perturbation theory. We provide a
gauge-independent criterion for baryon number preservation in place of the
conventional (gauge-dependent) criterion needed for successful electroweak
baryogenesis. We also review the arguments leading to the preservation
criterion and analyze several sources of theoretical uncertainties in obtaining
a numerical bound. In various beyond the standard model scenarios, a realistic
perturbative treatment will likely require knowledge of the complete two-loop
finite temperature effective potential and the one-loop sphaleron rate.Comment: 25 pages, 9 figures; v2 minor typos correcte
Myocardial Perfusion Imaging After Severe COVID-19 Infection Demonstrates Regional Ischemia Rather Than Global Blood Flow Reduction
Background: Acute myocardial damage is common in severe COVID-19. Post-mortem studies have implicated microvascular thrombosis, with cardiovascular magnetic resonance (CMR) demonstrating a high prevalence of myocardial infarction and myocarditis-like scar. The microcirculatory sequelae are incompletely characterized. Perfusion CMR can quantify the stress myocardial blood flow (MBF) and identify its association with infarction and myocarditis. Objectives: To determine the impact of the severe hospitalized COVID-19 on global and regional myocardial perfusion in recovered patients. Methods: A case-control study of previously hospitalized, troponin-positive COVID-19 patients was undertaken. The results were compared with a propensity-matched, pre-COVID chest pain cohort (referred for clinical CMR; angiography subsequently demonstrating unobstructed coronary arteries) and 27 healthy volunteers (HV). The analysis used visual assessment for the regional perfusion defects and AI-based segmentation to derive the global and regional stress and rest MBF. Results: Ninety recovered post-COVID patients {median age 64 [interquartile range (IQR) 54-71] years, 83% male, 44% requiring the intensive care unit (ICU)} underwent adenosine-stress perfusion CMR at a median of 61 (IQR 29-146) days post-discharge. The mean left ventricular ejection fraction (LVEF) was 67 ± 10%; 10 (11%) with impaired LVEF. Fifty patients (56%) had late gadolinium enhancement (LGE); 15 (17%) had infarct-pattern, 31 (34%) had non-ischemic, and 4 (4.4%) had mixed pattern LGE. Thirty-two patients (36%) had adenosine-induced regional perfusion defects, 26 out of 32 with at least one segment without prior infarction. The global stress MBF in post-COVID patients was similar to the age-, sex- and co-morbidities of the matched controls (2.53 ± 0.77 vs. 2.52 ± 0.79 ml/g/min, p = 0.10), though lower than HV (3.00 ± 0.76 ml/g/min, p< 0.01). Conclusions: After severe hospitalized COVID-19 infection, patients who attended clinical ischemia testing had little evidence of significant microvascular disease at 2 months post-discharge. The high prevalence of regional inducible ischemia and/or infarction (nearly 40%) may suggest that occult coronary disease is an important putative mechanism for troponin elevation in this cohort. This should be considered hypothesis-generating for future studies which combine ischemia and anatomical assessment
Biofilm development by clinical isolates of Staphylococcus spp. from retrieved orthopedic prostheses
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Mood disorder in idiopathic pulmonary fibrosis: response to pulmonary rehabilitation
Supplementary materials are available online at https://openres.ersjournals.com/content/9/3/00585-2022.figures-only#fig-data-supplementary-materials .Copyright © The authors 2023. Background: Pulmonary rehabilitation improves mood disorder in COPD, but there are limited data in idiopathic pulmonary fibrosis (IPF). The aims of this cohort study were to investigate whether pulmonary rehabilitation reduces mood disorder in IPF, and estimate the minimal important difference (MID) of the Hospital Anxiety and Depression Scale (HADS).
Methods: HADS and core pulmonary rehabilitation outcomes were measured in 166 participants before and after an 8-week, in-person, outpatient pulmonary rehabilitation programme. Anchor- and distribution-based methods were used to calculate the MID of HADS-Anxiety (A) and HADS-Depression (D).
Results: Suggestive or probable anxiety and depression (HADS ≥8) were present in 35% and 37% of participants, respectively, at baseline, and this reduced significantly following pulmonary rehabilitation (post-pulmonary rehabilitation: HADS-A 23%, HADS-D 26%). Overall, there was a significant reduction in HADS-D (mean change −1.1, 95% CI −1.6– −0.5), but not HADS-A (−0.6, −1.3–0.15) with pulmonary rehabilitation. Subgroup analysis of those with HADS ≥8 revealed significant improvements in HADS domains (mean change: HADS-A −4.5, 95% CI −5.7– −3.4; median change: HADS-D −4.0, interquartile range −6.0– −1.0). The mean (range) MID estimates for HADS-A and HADS-D were −2 (−2.3– −1.7) and −1.2 (−1.9– −0.5), respectively.
Conclusion: In people with IPF and suggestive or probable mood disorder, pulmonary rehabilitation reduces anxiety and depression.National Institute for Health Research Doctoral Research Fellowship (2014-07-089); Medical Research Council New Investigator Research Grant (98576)
Intranasal Immunization with an Archaeal Lipid Mucosal Vaccine Adjuvant and Delivery Formulation Protects against a Respiratory Pathogen Challenge
Archaeal lipid mucosal vaccine adjuvant and delivery (AMVAD) is a safe mucosal adjuvant that elicits long lasting and memory boostable mucosal and systemic immune responses to model antigens such as ovalbumin. In this study, we evaluated the potential of the AMVAD system for eliciting protective immunity against mucosal bacterial infections, using a mouse model of intranasal Francisella tularensis LVS (LVS) challenge. Intranasal immunization of mice with cell free extract of LVS (LVSCE) adjuvanted with the AMVAD system (LVSCE/AMVAD) induced F. tularensis-specific antibody responses in sera and bronchoalveolar lavage fluids, as well as antigen-specific splenocyte proliferation and IL-17 production. More importantly, the AMVAD vaccine partially protected the mice against a lethal intranasal challenge with LVS. Compared to LVSCE immunized and naïve mice, the LVSCE/AMVAD immunized mice showed substantial to significant reduction in pathogen burdens in the lungs and spleens, reduced serum and pulmonary levels of proinflammatory cytokines/chemokines, and longer mean time to death as well as significantly higher survival rates (p<0.05). These results suggest that the AMVAD system is a promising mucosal adjuvant and vaccine delivery technology, and should be explored further for its applications in combating mucosal infectious diseases
Differentiating Prodromal Dementia with Lewy Bodies from Prodromal Alzheimer’s Disease: A Pragmatic Review for Clinicians
\ua9 The Author(s) 2024.This pragmatic review synthesises the current understanding of prodromal dementia with Lewy bodies (pDLB) and prodromal Alzheimer’s disease (pAD), including clinical presentations, neuropsychological profiles, neuropsychiatric symptoms, biomarkers, and indications for disease management. The core clinical features of dementia with Lewy bodies (DLB)—parkinsonism, complex visual hallucinations, cognitive fluctuations, and REM sleep behaviour disorder are common prodromal symptoms. Supportive clinical features of pDLB include severe neuroleptic sensitivity, as well as autonomic and neuropsychiatric symptoms. The neuropsychological profile in mild cognitive impairment attributable to Lewy body pathology (MCI-LB) tends to include impairment in visuospatial skills and executive functioning, distinguishing it from MCI due to AD, which typically presents with impairment in memory. pDLB may present with cognitive impairment, psychiatric symptoms, and/or recurrent episodes of delirium, indicating that it is not necessarily synonymous with MCI-LB. Imaging, fluid and other biomarkers may play a crucial role in differentiating pDLB from pAD. The current MCI-LB criteria recognise low dopamine transporter uptake using positron emission tomography or single photon emission computed tomography (SPECT), loss of REM atonia on polysomnography, and sympathetic cardiac denervation using meta-iodobenzylguanidine SPECT as indicative biomarkers with slowing of dominant frequency on EEG among others as supportive biomarkers. This review also highlights the emergence of fluid and skin-based biomarkers. There is little research evidence for the treatment of pDLB, but pharmacological and non-pharmacological treatments for DLB may be discussed with patients. Non-pharmacological interventions such as diet, exercise, and cognitive stimulation may provide benefit, while evaluation and management of contributing factors like medications and sleep disturbances are vital. There is a need to expand research across diverse patient populations to address existing disparities in clinical trial participation. In conclusion, an early and accurate diagnosis of pDLB or pAD presents an opportunity for tailored interventions, improved healthcare outcomes, and enhanced quality of life for patients and care partners
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