Computational Modelling of the Interaction of Gold Nanoparticle with Lung Surfactant Monolayer

Copyright © Materials Research Society 2019. Lung surfactant (LS), a thin layer of phospholipids and proteins inside the alveolus of the lung is the first biological barrier to inhaled nanoparticles (NPs). LS stabilizes and protects the alveolus during its continuous compression and expansion by fine-Tuning the surface tension at the air-water interface. Previous modelling studies have reported the biophysical function of LS monolayer and its role, but many open questions regarding the consequences and interactions of airborne nano-sized particles with LS monolayer remain. In spite of gold nanoparticles (AuNPs) having a paramount role in biomedical applications, the understanding of the interactions between bare AuNPs (as pollutants) and LS monolayer components still unresolved. Continuous inhalation of NPs increases the possibility of lung ageing, reducing the normal lung functioning and promoting lung malfunction, and may induce serious lung diseases such as asthma, lung cancer, acute respiratory distress syndrome, and more. Different medical studies have shown that AuNPs can disrupt the routine lung functions of gold miners and promote respiratory diseases. In this work, coarse-grained molecular dynamics simulations are performed to gain an understanding of the interactions between bare AuNPs and LS monolayer components at the nanoscale. Different surface tensions of the monolayer are used to mimic the biological process of breathing (inhalation and exhalation). It is found that the NP affects the structure and packing of the lipids by disordering lipid tails. Overall, the analysed results suggest that bare AuNPs impede the normal biophysical function of the lung, a finding that has beneficial consequences to the potential development of treatments of various respiratory diseases

Soret and Dufour effects on MHD viscoelastic fluid flow through a vertical flat plate with constant suction

© 2016 Author(s). An attempt is made to represent the numerical solution of magnetohydrodynamics (MHD) viscoelastic fluid flow through an infinite vertical flat plate with constant suction in the presence of Soret and Dufour effects. The expressions of non-dimensional, coupled partial momentum, energy and concentration differential equations are obtained with the help of the usual non-dimensional variables. Implicit finite difference method is imposed to obtain the non-dimensional equations. Also the stability conditions and convergence criteria are analyzed. The effects of the various parameters entering into the problem on shear stress, Nusselt number, and Sherwood number are demonstrated graphically with physical interpretation

Polydisperse Aerosol Transport and Deposition in Upper Airways of Age-Specific Lung

A comprehensive understanding of airflow characteristics and particle transport in the human lung can be useful in modelling to inform clinical diagnosis, treatment, and management, including prescription medication and risk assessment for rehabilitation. One of the difficulties in clinical treatment of lung disorders lies in the patients' variable physical lung characteristics caused by age, amongst other factors, such as different lung sizes. A precise understanding of the comparison between different age groups with various flow rates is missing in the literature, and this study aims to analyse the airflow and aerosol transport within the age-specific lung. ANSYS Fluent solver and the large-eddy simulation (LES) model were employed for the numerical simulation. The numerical model was validated with the available literature and the computational results showed airway size-reduction significantly affected airflow and particle transport in the upper airways. This study reports higher deposition at the mouth-throat region for larger diameter particles. The overall deposition efficiency (DE) increased with airway size reduction and flow rate. Lung aging effected the pressure distribution and a higher pressure drop was reported for the aged lung as compared to the younger lung. These findings could inform medical management through individualised simulation of drug-aerosol delivery processes for the patient-specific lung

Stakeholder analysis for the development of a community pharmacy service aimed at preventing cardiovascular disease

© 2016 Elsevier Inc. Background Participatory approaches involving stakeholders across the health care system can help enhance the development, implementation and evaluation of health services. These approaches may be particularly useful in planning community pharmacy services and so overcome challenges in their implementation into practice. Conducting a stakeholder analysis is a key first step since it allows relevant stakeholders to be identified, as well as providing planners a better understanding of the complexity of the health care system. Objectives The main aim of this study was to conduct a stakeholder analysis to identify those individuals and organizations that could be part of a leading planning group for the development of a community pharmacy service (CPS) to prevent cardiovascular disease (CVD) in Australia. Methods An experienced facilitator conducted a workshop with 8 key informants of the Australian health care system. Two structured activities were undertaken. The first explored current needs and gaps in cardiovascular care and the role of community pharmacists. The second was a stakeholder analysis, using both ex-ante and ad-hoc approaches. Identified stakeholders were then classified into three groups according to their relative influence on the development of the pharmacy service. The information gathered was analyzed using qualitative content analysis. Results The key informants identified 46 stakeholders, including (1) patient/consumers and their representative organizations, (2) health care providers and their professional organizations and (3) institutions and organizations that do not directly interact with patients but organize and manage the health care system, develop and implement health policies, pay for health care, influence funding for health service research or promote new health initiatives. From the 46 stakeholders, a core group of 12 stakeholders was defined. These were considered crucial to the service's development because they held positions that could drive or inhibit progress. Secondary results of the workshop included: a list of needs and gaps in cardiovascular care (n = 6), a list of roles for community pharmacists in cardiovascular prevention (n = 12) and a list of potential factors (n = 7) that can hinder the integration of community pharmacy services into practice. Conclusions This stakeholder analysis provided a detailed picture of the wide range of stakeholders across the entire health care system that have a stake in the development of a community pharmacy service aimed at preventing CVD. Of these, a core group of key stakeholders, with complementary roles, can then be approached for further planning of the service. The results of this analysis highlight the relevance of establishing multilevel stakeholder groups for CPS planning

Comprehensive care of a patient with obesity of BMI >70 kg/m2

A 31-year-old woman, with a body mass index of 70.31 kg/m2 , presented with progressive worsening of dyspnoea for 3 days. She had multiple comorbidities, including obesity hypoventilation syndrome. The patient developed type II respiratory failure with respiratory acidosis along with multiorgan failure. She was intubated and put on a mechanical ventilator and treated with intravenous diuretics, subcutaneous low-molecularweight heparin and other supportive measures. Later, she was on noninvasive, continuous positive airway pressure ventilation overnight. She was prescribed a very-lowcalorie diet along with physiotherapy and exercise. The patient underwent bariatric surgery 2 months after resolution of acute illness. Ten months after surgery, her body weight reduced from 180 kg to 121 kg, and her general condition improved. Successful management before and after surgical intervention depends on multidisciplinary teamwork, which includes the dietician, physiotherapist, endocrinologist, pulmonologist, nursing care and other supportive care

Why could Electron Spin Resonance be observed in a heavy fermion Kondo lattice?

We develop a theoretical basis for understanding the spin relaxation processes in Kondo lattice systems with heavy fermions as experimentally observed by electron spin resonance (ESR). The Kondo effect leads to a common energy scale that regulates a logarithmic divergence of different spin kinetic coefficients and supports a collective spin motion of the Kondo ions with conduction electrons. We find that the relaxation rate of a collective spin mode is greatly reduced due to a mutual cancelation of all the divergent contributions even in the case of the strongly anisotropic Kondo interaction. The contribution to the ESR linewidth caused by the local magnetic field distribution is subject to motional narrowing supported by ferromagnetic correlations. The developed theoretical model successfully explains the ESR data of YbRh2Si2 in terms of their dependence on temperature and magnetic field.Comment: 5pages, 1 Figur

Malaria Prevalence in Endemic Districts of Bangladesh

BACKGROUND: Following the 1971 ban of DDT in Bangladesh, malaria cases have increased steadily. Malaria persists as a major health problem in the thirteen south-eastern and north-eastern districts of Bangladesh. At present the national malaria control program, largely supported by the Global Fund for AIDS, Tuberculosis and Malaria (GFATM), provides interventions including advocacy at community level, Insecticide Treated Net (ITN) distribution, introduction of Rapid Diagnostic Tests (RDT) and combination therapy with Coartem. It is imperative, therefore, that baseline data on malaria prevalence and other malaria indicators are collected to assess the effectiveness of the interventions and rationalize the prevention and control efforts. The objective of this study was to obtain this baseline on the prevalence of malaria and bed net use in the thirteen malaria endemic districts of Bangladesh. METHODS AND PRINCIPAL FINDINGS: In 2007, BRAC and ICDDR,B carried out a malaria prevalence survey in thirteen malaria endemic districts of Bangladesh. A multi-stage cluster sampling technique was used and 9750 blood samples were collected. Rapid Diagnostic Tests (RDT) were used for the diagnosis of malaria. The weighted average malaria prevalence in the thirteen endemic districts was 3.97%. In five south-eastern districts weighted average malaria prevalence rate was 6.00% and in the eight north-eastern districts weighted average malaria prevalence rate was (0.40%). The highest malaria prevalence was observed in Khagrachari district. The majority of the cases (90.18%) were P. falciparum infections. Malaria morbidity rates in five south-eastern districts was 2.94%. In eight north-eastern districts, morbidity was 0.07%. CONCLUSION AND SIGNIFICANCE: Bangladesh has hypoendemic malaria with P. falciparum the dominant parasite species. The malaria situation in the five north-eastern districts of Bangladesh in particular warrants urgent attention. Detailed maps of the baseline malaria prevalence and summaries of the data collected are provided along with the survey results in full, in a supplemental information

Topological crossovers near a quantum critical point

We study the temperature evolution of the single-particle spectrum $\epsilon(p)$ and quasiparticle momentum distribution $n(p)$ of homogeneous strongly correlated Fermi systems beyond a point where the necessary condition for stability of the Landau state is violated, and the Fermi surface becomes multi-connected by virtue of a topological crossover. Attention is focused on the different non-Fermi-liquid temperature regimes experienced by a phase exhibiting a single additional hole pocket compared with the conventional Landau state. A critical experiment is proposed to elucidate the origin of NFL behavior in dense films of liquid $^3$He.Comment: 7 pages, 6 figure

Discovery of charge order and corresponding edge state in kagome magnet FeGe

Kagome materials often host exotic quantum phases, including spin liquids, Chern gap, charge order, and superconductivity. Existing scanning microscopy studies of the kagome charge order have been limited to non-kagome surface layers. Here we tunnel into the kagome lattice of FeGe to uncover features of the charge order. Our spectroscopic imaging identifes a 2x2 charge order in the magnetic kagome lattice, resembling that discovered in kagome superconductors. Spin-mapping across steps of unit-cell-height demonstrates that this charge order emerges from spin-polarized electrons with an antiferromagnetic stacking order. We further uncover the correlation between antiferromagnetism and charge order anisotropy, highlighting the unusual magnetic coupling of the charge order. Finally, we detect a pronounced edge state within the charge order energy gap, which is robust against the irregular shape of the kagome lattice edges. We discuss our results with the theoretically considered topological features of the kagome charge order including orbital magnetism and bulk-boundary correspondence