1,965 research outputs found
Characterising Australian memory clinics: current practice and service needs informing national service guidelines
Background: Memory clinics (MCs) play a key role in accurate and timely diagnoses and treatment of dementia and mild cognitive impairment. However, within Australia, there are little data available on current practices in MCs, which hinder international comparisons for best practice, harmonisation efforts and national coordination. Here, we aimed to characterise current service profiles of Australian MCs. Methods: The âAustralian Dementia Network Survey of Expert Opinion on Best Practice and the Current Clinical Landscapeâ was conducted between August-September 2020 as part of a larger-scale Delphi process deployed to develop national MC guidelines. In this study, we report on the subset of questions pertaining to current practice including wait-times and post-diagnostic care. Results: Responses were received from 100 health professionals representing 60 separate clinics (45 public, 11 private, and 4 university/research clinics). The majority of participants were from clinics in metropolitan areas (79%) and in general were from high socioeconomic areas. While wait-times varied, only 28.3% of clinics were able to offer an appointment within 1-2 weeks for urgent referrals, with significantly more private clinics (58.3%) compared to public clinics (19.5%) being able to do so. Wait-times were less than 8 weeks for 34.5% of non-urgent referrals. Only 20.0 and 30.9% of clinics provided cognitive interventions or post-diagnostic support respectively, with 7.3% offering home-based reablement programs, and only 12.7% offering access to group-based education. Metropolitan clinics utilised neuropsychological assessments for a broader range of cases and were more likely to offer clinical trials and access to research opportunities. Conclusions: In comparison to similar countries with comprehensive government-funded public healthcare systems (i.e., United Kingdom, Ireland and Canada), wait-times for Australian MCs are long, and post-diagnostic support or evidence-based strategies targeting cognition are not common practice. The timely and important results of this study highlight a need for Australian MCs to adopt a more holistic service of multidisciplinary assessment and post-diagnostic support, as well as the need for the number of Australian MCs to be increased to match the rising number of dementia cases
Conclusive quantum steering with superconducting transition edge sensors
Quantum steering allows two parties to verify shared entanglement even if one
measurement device is untrusted. A conclusive demonstration of steering through
the violation of a steering inequality is of considerable fundamental interest
and opens up applications in quantum communication. To date all experimental
tests with single photon states have relied on post-selection, allowing
untrusted devices to cheat by hiding unfavourable events in losses. Here we
close this "detection loophole" by combining a highly efficient source of
entangled photon pairs with superconducting transition edge sensors. We achieve
an unprecedented ~62% conditional detection efficiency of entangled photons and
violate a steering inequality with the minimal number of measurement settings
by 48 standard deviations. Our results provide a clear path to practical
applications of steering and to a photonic loophole-free Bell test.Comment: Preprint of 7 pages, 3 figures; the definitive version is published
in Nature Communications, see below. Also, see related experimental work by
A. J. Bennet et al., arXiv:1111.0739 and B. Wittmann et al., arXiv:1111.076
Stage-Specific Inhibition of MHC Class I Presentation by the Epstein-Barr Virus BNLF2a Protein during Virus Lytic Cycle
gamma-herpesvirus Epstein-Barr virus (EBV) persists for life in infected individuals despite the presence of a strong immune response. During the lytic cycle of EBV many viral proteins are expressed, potentially allowing virally infected cells to be recognized and eliminated by CD8+ T cells. We have recently identified an immune evasion protein encoded by EBV, BNLF2a, which is expressed in early phase lytic replication and inhibits peptide- and ATP-binding functions of the transporter associated with antigen processing. Ectopic expression of BNLF2a causes decreased surface MHC class I expression and inhibits the presentation of indicator antigens to CD8+ T cells. Here we sought to examine the influence of BNLF2a when expressed naturally during EBV lytic replication. We generated a BNLF2a-deleted recombinant EBV (ÎBNLF2a) and compared the ability of ÎBNLF2a and wild-type EBV-transformed B cell lines to be recognized by CD8+ T cell clones specific for EBV-encoded immediate early, early and late lytic antigens. Epitopes derived from immediate early and early expressed proteins were better recognized when presented by ÎBNLF2a transformed cells compared to wild-type virus transformants. However, recognition of late antigens by CD8+ T cells remained equally poor when presented by both wild-type and ÎBNLF2a cell targets. Analysis of BNLF2a and target protein expression kinetics showed that although BNLF2a is expressed during early phase replication, it is expressed at a time when there is an upregulation of immediate early proteins and initiation of early protein synthesis. Interestingly, BNLF2a protein expression was found to be lost by late lytic cycle yet ÎBNLF2a-transformed cells in late stage replication downregulated surface MHC class I to a similar extent as wild-type EBV-transformed cells. These data show that BNLF2a-mediated expression is stage-specific, affecting presentation of immediate early and early proteins, and that other evasion mechanisms operate later in the lytic cycle
Simplified mathematical model of proton exchange membrane fuel cell based on horizon fuel cell stack
This paper presents a simplified zero-dimensional mathematical model for a self-humidifying proton exchange membrane (PEM) fuel cell stack of 1 kW. The model incorporates major electric and thermodynamic variables and parameters involved in the operation of the PEM fuel cell under different operational conditions. Influence of each of these parameters and variables upon the operation and the performance of the PEM fuel cell are investigated. The mathematical equations are modeled by using MatlabâSimulink tools in order to simulate the operation of the developed model with a commercial available 1 kW horizon PEM fuel cell stack (H-1000), which is used for the purposes of model validation and tuning of the developed model. The model can be extrapolated to higher wattage fuel cells of similar arrangements. New equation is presented to determine the impact of using air to supply the PEM fuel cell instead of pure oxygen upon the concentration losses and the output voltage when useful current is drawn from it
Uneventful Disappearance of a Large Left Atrial Ball Thrombus with Enoxaparin in a Patient with Mitral Stenosis Associated with Pregnancy
An atrial thrombus is a relatively common echocardiographic finding in patients with mitral valve stenosis (MVS) and atrial fibrillation (AF). However, a âball thrombusâ or floating thrombus in the left atrium is a rare and specific entity associated with MVS. A 24-year-old woman with rheumatic MVS presented with complaints of progressive dyspnea and inferior limbs edema that began 23 days earlier after a caesarean operation for stillbirth carried out at 8 months of pregnancy. At the time of hospitalization, she was in New York Heart Association functional class III and the ECG showed sinus rhythm. Transthoracic color-flow Doppler echocardiography revealed a thick, stenotic mitral valve with a valvular area of 0.9 cm2, and an echogenic large left-atrial mass diagnosed as a free-floating left-atrial thrombus that was corroborated by transesophageal echocardiography. She refused surgery and was treated medically, and low molecular weight heparin (LMWH) (enoxaparin 80 mg/12 h) was given for 14 days and was discharged uneventfully on coumarin. Two days before discharge, a transthoracic and transesophageal ecocardiography showed disappearance of the ball thrombus uneventfully leaving spontaneous echo contrast inside the left atrium. To the best of our knowledge, this is the first case showing disappearance of a giant left atrial ball thrombus with LMWH treatment in a patient with severe MVS during sinus rhythm associated with pregnancy
Treatment of chronic anterior shoulder dislocation by open reduction and simultaneous Bankart lesion repair
<p>Abstract</p> <p>Background</p> <p>Untreated chronic shoulder dislocation eventually leads to functional disability and pain. Open reduction with different fixation methods have been introduced for most chronic shoulder dislocation. We hypothesized that open reduction and simultaneous Bankart lesion repair in chronic anterior shoulder dislocation obviates the need for joint fixation and leads to better results than previously reported methods.</p> <p>Methods</p> <p>Eight patients with chronic anterior dislocation of shoulder underwent open reduction and capsulolabral complex repair after an average delay of 10 weeks from injury. Early motion was allowed the day after surgery in the safe position and the clinical and radiographic results were analyzed at an average follow-up of one year.</p> <p>Results</p> <p>The average Rowe and Zarin's score was 86 points. Four out of eight shoulders were graded as excellent, three as good and one as fair (Rowe and Zarins system). All patients were able to perform their daily activities and they had either mild or no pain. Anterior active forward flexion loss averaged 18 degrees, external active rotation loss averaged 17.5 degrees and internal active rotation loss averaged 3 vertebral body levels. Mild degenerative joint changes were noted in one patient.</p> <p>Conclusion</p> <p>The results show that the overall prognosis for this method of operation is more favorable than the previously reported methods and we recommend concomitant open reduction and capsulolabral complex repair for the treatment of old anterior shoulder dislocation.</p> <p>Level of Evidence</p> <p>Therapeutic study, Level IV (case series [no, or historical, control group])</p
Earthquake lubrication and healing explained by amorphous nanosilica
During earthquake propagation, geologic faults lose their strength, then strengthen as slip slows and stops. Many slip-weakening mechanisms are active in the upper-mid crust, but healing is not always well-explained. Here we show that the distinct structure and rate-dependent properties of amorphous nanopowder (not silica gel) formed by grinding of quartz can cause extreme strength loss at high slip rates. We propose a weakening and related strengthening mechanism that may act throughout the quartz-bearing continental crust. The action of two slip rate-dependent mechanisms offers a plausible explanation for the observed weakening: thermally-enhanced plasticity, and particulate flow aided by hydrodynamic lubrication. Rapid cooling of the particles causes rapid strengthening, and inter-particle bonds form at longer timescales. The timescales of these two processes correspond to the timescales of post-seismic healing observed in earthquakes. In natural faults, this nanopowder crystallizes to quartz over 10sâ100s years, leaving veins which may be indistinguishable from common quartz veins
Severe vitamin D deficiency in 6 Canadian First Nation formula-fed infants
Background. Rickets was first described in the 17th century and vitamin D deficiency was recognized as the underlying cause in the early 1900s. Despite this long history, vitamin D deficiency remains a significant health concern. Currently, vitamin D supplementation is recommended in Canada for breast fed infants. There are no recommendations for supplementation in formula-fed infants. Objective. The objective of this report is to bring attention to the risk of severe vitamin D deficiency in high risk, formula fed infants. Design. A retrospective chart review was used to create this clinical case series. Results. Severe vitamin D deficiency was diagnosed in six formula-fed infants over a two-and-a-half year period. All six infants presented with seizures and they resided in First Nation communities located at latitude 54 in the province of Manitoba. While these infants had several risk factors for vitamin D deficiency, they were all receiving cow's milk based formula supplemented with 400 IU/L of vitamin D. Conclusion. This report suggests that current practice with regards to vitamin D supplementation may be inadequate, especially for high-risk infants. Health care professionals providing service to infants in a similar situation should be aware of this preventable condition. Hopefully this would contribute to its prevention, diagnosis and management
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