Two dimensional LiMgAs; a novel Topological Quantum Catalyst for Hydrogen Evolution Reaction

Quantum materials such as Topological Insulators (TI) have been promising due to diverse applications of their robust surface/edge states in the bulk (3D) and two-dimensional (2D) regime. Such conducting surface states in 3D systems, host "\textit{electron bath}" which are known to facilitate catalysis. However, the analogous effects in 2D scenarios wherein, conducting helical edge states giving rise to Fermionic accumulation has been scarcely addressed. Using density functional theory based \textit{first-principles} calculations, we demonstrate that, the conducting edge states in 2D TI such as LiMgAs can be exploited to facilitate excellent catalytic response towards Hydrogen evolution reactions. The Gibbs free energy in such cases was found to be as low as $-$0.02 eV which is quite superior as compared to other materials reported in literature. The concept presented herein can be extended to other well known 2D TI and used to realise novel topological quantum catalysts for ultra-high performance and efficient catalytic applications.Comment: 5 pages, 4 figure

The impact of pulmonary regurgitation on right ventricular size and function in patients with repaired tetralogy of Fallot and additional haemodynamic abnormalities

Purpose: Right ventricular (RV) outflow tract obstruction (RVOTO) was demonstrated to be protective against RV dilatation in patients with repaired tetralogy of Fallot and chronic pulmonary regurgitation (PR). We hypothesised that the presence of additional haemodynamic abnormalities (more than mild tricuspid regurgitation, residual ventricular septal defect) reduces this protective association. Accordingly, we aimed to assess the impact of PR on RV size and function in this population. Material and methods: Consecutive patients with additional haemodynamic abnormalities after tetralogy of Fallot (TOF) repair, who had undergone cardiovascular magnetic resonance, were included. Results: Out of 90 patients studied, 18 individuals (mean age 32.5 ± 10.7 years, 72.2% males) met the inclusion criteria. There were no differences in RV volumes and ejection fraction between patients with and without RVOTO. Neither PR fraction (PRF) nor PR volume (PRV) correlated with RV end-diastolic volume (r = 0.36; p = 0.15 and r = 0.37; p = 0.14, respectively, for PRF and PRV) or RV end-systolic volume (r = 0.2; p = 0.42 and r = 0.19; p = 0.45, respectively, for PRF and PRV). Similarly, no significant correlations were observed between PRF or PRV and RV ejection fraction (r = –0.04; p = 0.87 and r = –0.03; p = 0.9, respectively). Conclusions: Additional haemodynamic abnormalities are associated with the abolition of the protective effect of RVOTO on RV size. There was no significant relationship between measures of PR and RV volumes in patients after TOF repair with concomitant haemodynamic abnormalities. These abnormalities acted as confounding factors in the assessment of the impact of pulmonary regurgitation on RV size and function

Potential of lactoferrin to prevent antibiotic-induced Clostridium difficile infection

Objectives: C. difficile infection (CDI) is a global healthcare problem. Recent evidence suggests that the availability of iron may be important for C. difficile growth. This study evaluated the comparative effects of iron-depleted (1% Fe3+ saturated) bovine apo-lactoferrin (apo-bLf) and iron-saturated (85% Fe3+ saturated) bovine holo-lactoferrin (holo-bLf) in a human in vitro gut model that simulates CDI. Methods: Two parallel triple-stage chemostat gut models were inoculated with pooled human faeces and spiked with C. difficile spores (strain 027 210, PCR ribotype 027). Holo- or apo-bLf was instilled (5mg/mL, once daily) for 35 days. After 7 days, clindamycin was instilled (33.9mg/L, four times daily) to induce simulated CDI. Indigenous microflora populations, C. difficile total counts and spores , cytotoxin titres, short-chain fatty acids, biometals, lactoferrin, and iron content of lactoferrin were monitored daily. Results: In the apo-bLf model, germination of C. difficile spores occurred 6 days post-clindamycin, followed by rapid vegetative cell proliferation and detectable toxin. By contrast, in the holo-bLf model, only a modest vegetative cell population was observed until 16 days post-antibiotic. Notably, no toxin was detected in this model. In separate batch culture experiments, holo-bLf prevented C. difficile vegetative cell growth and toxin production, whereas apo-bLf and iron alone did not. Conclusions: Holo-bLf but not apo-bLf delayed C. difficile growth and prevented toxin production in a human gut model of CDI. This inhibitory effect may be iron-independent. These observations suggest that bLf in its iron-saturated state could be used as a novel preventative or treatment strategy for CDI

Threat of allergenic airborne grass pollen in Szczecin, NW Poland: the dynamics of pollen seasons, effect of meteorological variables and air pollution

The dynamics of Poaceae pollen season, in particularly that of the Secale genus, in Szczecin (western Poland) 2004–2008 was analysed to establish a relationship between the meteorological variables, air pollution and the pollen count of the taxa studied. Consecutive phases during the pollen season were defined for each taxon (1, 2.5, 5, 25, 50, 75, 95, 97.5, 99% of annual total), and duration of the season was determined using the 98% method. On the basis of this analysis, the temporary differences in the dynamics of the seasons were most evident for Secale in 2005 and 2006 with the longest main pollen season (90% total pollen). The pollen season of Poaceae started the earliest in 2007, when thermal conditions were the most favourable. Correlation analysis with meteorological factors demonstrated that the relative humidity, mean and maximum air temperature, and rainfall were the factors influencing the average daily pollen concentrations in the atmosphere; also, the presence of air pollutants such as ozone, PM10 and SO2 was statistically related to the pollen count in the air. However, multiple regression models explained little part of the total variance. Atmospheric pollution induces aggravation of symptoms of grass pollen allergy

Wpływ relacji społecznych na rozwój rolnictwa ekologicznego na przykładzie powiatu świdwińskiego

Subject and purpose of work: The article presents the role of social relations between organic farmers and organic farming environment (representatives of local government, non-governmental organizations) in the development of organic farming in the Świdwin County. The aim of the paper is to explore the role of local leader and social capital in the process of organic the farming development in selected geographical area. Materials and methods: The research is based on both the analysis of existing data and the results of the study (Individual In-depth Interviews - IDIs and Focus Group Interview - FGI) carried out in 2016 with organic farmers and organic farming stakeholders incl. representatives of local government and non-governmental organizations. Results: The study shows a positive correlation between high level of social capital and a strong sector of organic farming. The key significance is given to a local leader activity. Conclusions: The development of a close network of social relations between organic farmers, and between organic farmers and their environment (representatives of local government and non-governmental organizations) determines the development of a strong sector of organic farming in the area. An important condition for the organic farming development is also recognition of this type of resources by the local authorities.Przedmiot i cel pracy: Artykuł ukazuje wpływ relacji społecznych pomiędzy rolnikami prowadzącymi gospodarstwa ekologiczne i otoczeniem instytucjonalnym (przedstawicielami samorządu lokalnego, instytucji pozarządowych) na rozwój rolnictwa ekologicznego na terenie powiatu świdwińskiego. Celem jest ukazanie roli silnego lokalnego lidera oraz kapitału społecznego w rozwoju rolnictwa ekologicznego na wybranym obszarze. Materiały i metody: W opracowaniu wykorzystano zarówno dane zastane dotyczące badanego obszaru jak i wyniki badań własnych realizowanych w 2016 roku (indywidualnych wywiadów pogłębionych – ang. IDI, oraz grupowego wywiadu zogniskowanego – ang. FGI) z rolnikami prowadzącymi gospodarstwa ekologiczne oraz z przedstawicielami samorządu i instytucji pozarządowych. Wyniki: Z przeprowadzonych badań wynika, że istnieje pozytywna korelacja pomiędzy wysokim kapitałem społecznym a silnym sektorem rolnictwa ekologicznego. Duże znaczenie odgrywa lider lokalny. Wnioski: Wypracowanie gęstej sieci relacji społecznych pomiędzy rolnikami prowadzącymi gospodarstwa ekologiczne, a także rolnikami i przedstawicielami władz samorządowych i instytucji pozarządowych warunkuje rozwój silnego sektora rolnictwa ekologicznego na danym terenie. Ważnym warunkiem rozwoju rolnictwa ekologicznego jest również dostrzeżenie i docenienie tego typu zasobu przez lokalne władze

Assessment of standing balance in patients after ankle fractures

Purpose: The objective of the study is to evaluate the degree of balance disorders in patients with surgical treatment of ankle fractures with the use of stabilometric examinations.Methods: The subjects in the study were 21 patients with ankle fractures treated surgically, within one year of the procedure. The control group were 20 healthy subjects. The balance was evaluated with the use of force platform in standing posture in both single and double limb stance. The analysed parameters were the transition area of the centre of feet pressure (COP), the length of the COP path and the COP velocity. The range of movement in the ankle joint and the intensification of pain were also measured.Results: In the balance evaluation in double limb stance, there were no statistically significant differences. A significant difference was found in the attempts of single limb-stance An average value of COP transition area in the study group was 261.2 mm2 in single stance (on the right operated limb) and in the control group – 93.2 mm2, so the difference was statistically significant (p=0,0096). The presence of pain, the presence or the removal of anastomosis had no significant influence on the balance of the studied subjects. Also a significant correlation between the balance of the subjects and their age was found.Conclusions: The balance in single limb stance after an instable ankle fracture within one year of the surgical procedure is significantly poorer in comparison with healthy subjects. Elderly persons have significantly poorer balance control

Does the use of acetylsalicylic acid have an influence on our vision?

Katarzyna Michalska-Małecka,1,2 Agnieszka Regucka,2 Dorota Śpiewak,2 Magdalena Sosnowska-Pońska,2 Alfred Niewiem2 1Department of Ophthalmology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland; 2University Clinical Center, University Hospital Medical University of Silesia, Katowice, Poland Purpose: Acetylsalicylic acid (ASA) is one of the most commonly used drugs in the world due to its anti-inflammatory, analgesic, and antipyretic properties. This review aims to describe the relationship between acetylsalicylic acid and age-related macular degeneration (AMD) – a chronic disease that causes deterioration of visual acuity and is one of the most common ophthalmological diseases these days. Methods: Data presented in this review were collected from both research and review articles concerning ophthalmology and pharmacology. Results: The results of the studies analyzed in this review are not unambiguous. Moreover, the studies are not homogenous. They differed from one another in terms of the number of patients, the age criteria, the ASA dose, and the duration of control period. The reviewed studies revealed that ASA therapy, which is applied as a protection in cardiovascular diseases in patients with early forms of AMD and geographic atrophy, should not be discontinued. Conclusion: On the basis of the present studies, it cannot be unequivocally said whether ASA influences people’s vision and if people endangered with AMD progression or who are diagnosed with AMD should use this drug. It may increase the risk of AMD, but it can also reduce the risk of life-threatening conditions. The authors suggest that in order to avoid possible risks of AMD development, people who frequently take ASA should have their vision checked regularly. Keywords: acetylsalicylic acid, AMD, lipofuscin genesis, drusen genesis, retinal pigment epithelium cells, geographic atroph

First Principles Calculations of the Formation Energy of the Neutral Vacancy in Germanium

score: 0collation: 241-24