Pentagonal nanowires: a first-principles study of atomic and electronic structure

We performed an extensive first-principles study of nanowires in various pentagonal structures by using pseudopotential plane wave method within the density functional theory. Our results show that nanowires of different types of elements, such as alkali, simple, transition and noble metals and inert gas atoms, have a stable structure made from staggered pentagons with a linear chain perpendicular to the planes of the pentagons and passing through their centers. This structure exhibits bond angles close to those in the icosahedral structure. However, silicon is found to be energetically more favorable in the eclipsed pentagonal structure. These quasi one dimensional pentagonal nanowires have higher cohesive energies than many other one dimensional structures and hence may be realized experimentally. The effect of magnetic state are examined by spin-polarized calculations. The origin of the stability are discussed by examining optimized structural parameters, charge density and electronic band structure, and by using analysis based on the empirical Lennard-Jones type interaction. Electronic band structure of pentagonal wires of different elements are discussed and their effects on quantum ballistic conductance are mentioned. It is found that the pentagonal wire of silicon exhibits metallic band structure.Comment: 4 figures, accepted for publication in Phys. Rev.

Provision of a comprehensive medicines review is associated with lower mortality risk for residents of aged care facilities: a retrospective cohort study

Background: no studies have examined the impact of residential medication management review (RMMR, a 24-year government subsidised comprehensive medicines review program) in Australian residential aged care facilities (RACFs) on hospitalisation or mortality. Objective: to examine associations between RMMR provision in the 6–12 months after RACF entry and the 12-month risk of hospitalisation and mortality among older Australians in RACFs. Design retrospective cohort study. Subjects: individuals aged 65–105 years taking at least one medicine, who entered an RACF in three Australian states between 1 January 2012 and 31 December 2015 and spent at least 6 months in the RACF (n = 57,719). Methods: Cox regression models estimated adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) for associations between RMMR provision and mortality. Adjusted subdistribution hazard ratios were estimated for associations between RMMR provision and next (i) emergency department (ED) presentation or unplanned hospitalisation or (ii) fall-related ED presentation or hospitalisation. Results: there were 12,603 (21.8%) individuals who received an RMMR within 6–12 months of RACF entry, of whom 22.2% (95%CI 21.4–22.9) died during follow-up, compared with 23.3% (95%CI 22.9–23.7) of unexposed individuals. RMMR provision was associated with a lower risk of death due to any cause over 12-months (aHR 0.96, 95%CI 0.91–0.99), but was not associated with ED presentations or hospitalisations for unplanned events or falls. Conclusions: provision of an RMMR in the 6–12 months after RACF entry is associated with a 4.4% lower mortality risk over 12-months but was not associated with changes in hospitalisations for unplanned events or falls.Janet K Sluggett, Gillian E Caughey, Tracy Air, Max Moldovan, Catherine Lang, Grant Martin, Stephen R Carter, Shane Jackson, Andrew C Stafford, Steve L Wesselingh, Maria C Inaci

International consensus recommendations on the management of people with haemophilia B

Haemophilia B is a rare X-linked genetic deficiency of coagulation factor IX (FIX) that, if untreated, can cause recurrent and disabling bleeding, potentially leading to severe arthropathy and/or life-threatening haemorrhage. Recent decades have brought significant improvements in haemophilia B management, including the advent of recombinant FIX and extended half-life FIX. This therapeutic landscape continues to evolve with several non-factor replacement therapies and gene therapies under investigation. Given the rarity of haemophilia B, the evidence base and clinical experience on which to establish clinical guidelines are relatively sparse and are further challenged by features that are distinct from haemophilia A, precluding extrapolation of existing haemophilia A guidelines. Due to the paucity of formal haemophilia B-specific clinical guidance, an international Author Group was convened to develop a clinical practice framework. The group comprised 15 haematology specialists from Europe, Australia, Japan, Latin America and North America, covering adult and paediatric haematology, laboratory medicine and biomedical science. A hybrid approach combining a systematic review of haemophilia B literature with discussion of clinical experience utilized a modified Delphi format to develop a comprehensive set of clinical recommendations. This approach resulted in 29 recommendations for the clinical management of haemophilia B across five topics, including product treatment choice, therapeutic agent laboratory monitoring, pharmacokinetics considerations, inhibitor management and preparing for gene therapy. It is anticipated that this clinical practice framework will complement existing guidelines in the management of people with haemophilia B in routine clinical practice and could be adapted and applied across different regions and countries

Medicines use before and after comprehensive medicines review among residents of long-term care facilities: a retrospective cohort study

Background: Residential Medication Management Review (RMMR) is a subsidized comprehensive medicines review program for individuals in Australian residential aged care facilities (RACFs). This study examined weekly trends in medicines use in the four months before and after an RMMR and among a comparison group of residents who did not receive an RMMR. Methods: This retrospective cohort study included individuals aged 65 to 105 years who first entered permanent care between 1/1/2012 and 31/12/2016 in South Australia, Victoria, or New South Wales, and were taking at least one medicine. Individuals with an RMMR within 12 months of RACF entry were classified into one of three groups: (i) RMMR within 0 to 3 months, (ii) 3 to 6 months, or (iii) within 6 to 12 months of RACF entry. Individuals without RMMRs were included in the comparison group. Weekly trends in the number of defined daily doses per 1000 days were determined in the four months before and after the RMMR (or assigned index date in the comparison group) for 14 medicine classes. Results: 113909 individuals from 1979 RACFs were included, of whom 55021 received an RMMR. Across all three periods examined, decreased use of statins and proton pump inhibitors was observed post-RMMR in comparison to those without RMMRs. Decreases in calcium channel blockers, benzodiazepines/zopiclone, and antidepressants were observed following RMMR provision in the 3–6 and 6–12 months after RACF entry. Negligible changes in antipsychotic use were also observed following an RMMR in the 6–12 months after RACF entry by comparison to those without RMMRs. No changes in use of opioids, ACE inhibitors/sartans, beta blockers, loop diuretics, oral anticoagulants, or medicines for osteoporosis, diabetes or the cognitive symptoms of dementia were observed post-RMMR. Conclusions: For six of the 14 medicine classes investigated, modest changes in weekly trends in use were observed after the provision of an RMMR in the 6–12 months after RACF entry compared to those without RMMRs. Findings suggest that activities such as medicines reconciliation may be prioritized when an RMMR is provided on RACF entry, with deprescribing more likely after an RMMR the longer a resident has been in the RACF.Janet K. Sluggett, Gillian E. Caughey, Tracy Air, Max Moldovan, Catherine Lang, Grant Martin, Stephen R. Carter, Shane Jackson, Andrew C. Stafford, Steve L. Wesselingh, and Maria C. Inaci