759 research outputs found
Antibiotic repeat prescriptions: are patients not re-filling them properly?
Objective: This study aimed to explore patients’ utilization of repeat prescriptions for antibiotics indicated in upper respiratory tract infections (URTI). An emphasis was placed on whether the current system of repeat prescriptions contributes to patients self-diagnosing infections and if so, identify the common reasons for this. Methods: This is a prospective study of self-reported use of repeat antibiotic prescriptions by pharmacy consumers presenting with repeat prescriptions for antibiotics commonly indicated in URTIs. Data were collected via self-completed surveys in Perth metropolitan pharmacies. Results: A total of 123 respondents participated in this study from 19 Perth metropolitan pharmacies. Of the respondents, approximately a third of them (33.9%) presented to the pharmacy to fill their antibiotic repeat prescription one month or more from the time the original prescription was written (i.e. time when original diagnosis was made by a doctor). Over two thirds of respondents indicated to not have consulted their doctor prior to presenting to the pharmacy to have their antibiotic repeat prescription dispensed (i.e. 68.3%). The most common reasons for this were that their ‘doctor had told them to take the second course’ (38%), followed by potential self-diagnosis (29%), i.e. ‘they had the same symptoms as the last time they took the antibiotics’. Approximately one third (33.1%) of respondents indicated they ‘were not told what the repeat prescription was needed for’ when they were originally prescribed the antibiotic. Respondents who presented to fill their repeat prescription more than 2 weeks after the original prescription written were more likely not have consulted their doctor (p = 0.006, 95% CI [1.16, 2.01]) and not to know why their repeat was needed (p = 0.010, 95% CI [1.07,2.18]).Conclusions: Findings of this study suggested that the current 12 month validity of antibiotics repeat prescriptions is potentially contributing to patients’ self-diagnosis of URTIs and therefore potential misuse of antibiotics. This may be contributing to the rise of antimicrobial resistance. The study also outlines some common reasons for patients potentially self-diagnosing URTIs when using repeat prescriptions. Larger Australian studies are needed to confirm these findings
Implications of a Modified Higgs to Diphoton Decay Width
Motivated by recent results from Higgs searches at the Large Hadron Collider,
we consider possibilities to enhance the diphoton decay width of the Higgs
boson over the Standard Model expectation, without modifying either its
production rate or the partial widths in the WW and ZZ channels. Studying
effects of new charged scalars, fermions and vector bosons, we find that
significant variations in the diphoton width may be possible if the new
particles have light masses of the order of a few hundred GeV and sizeable
couplings to the Higgs boson. Such couplings could arise naturally if there is
large mass mixing between two charged particles that is induced by the Higgs
vacuum expectation value. In addition, there is generically also a shift in the
Z + Gamma partial width, which in the case of new vector bosons tends to be of
similar magnitude as the shift in the diphoton partial width, but smaller in
other cases. Therefore simultaneous measurements in these two channels could
reveal properties of new charged particles at the electroweak scale.Comment: 29 pages, 8 figures; v2: updated references and minor improvements in
presentations; v3: sign of the scalar contribution to Z+Gamma amplitudes
fixed. Related figures update
Systematic review and meta-analysis of the reliability and discriminative validity of cartilage compositional MRI in knee osteoarthritis.
OBJECTIVE: To assess reliability and discriminative validity of cartilage compositional magnetic resonance imaging (MRI) in knee osteoarthritis (OA). DESIGN: The study was carried out per PRISMA recommendations. We searched MEDLINE and EMBASE (1974 - present) for eligible studies. We performed qualitative synthesis of reliability data. Where data from at least two discrimination studies were available, we estimated pooled standardized mean difference (SMD) between subjects with and without OA. Discrimination analyses compared controls and subjects with mild OA (Kellgren-Lawrence (KL) grade 1-2), severe OA (KL grade 3-4) and OA not otherwise specified (NOS) where not possible to stratify. We assessed quality of the evidence using Quality Appraisal of Diagnostic Reliability (QAREL) and Quality Assessment of Diagnostic Accuracy (QUADAS-2) tools. RESULTS: Fifty-eight studies were included in the reliability analysis and 26 studies were included in the discrimination analysis, with data from a total of 2,007 knees. Intra-observer, inter-observer and test-retest reliability of compositional techniques were excellent with most intraclass correlation coefficients >0.8 and coefficients of variation <10%. T1rho and T2 relaxometry were significant discriminators between subjects with mild OA and controls, and between subjects with OA (NOS) and controls (P < 0.001). T1rho showed best discrimination for mild OA (SMD [95% CI] = 0.73 [0.40 to 1.06], P < 0.001) and OA (NOS) (0.60 [0.41 to 0.80], P < 0.001). Quality of evidence was moderate for both parts of the review. CONCLUSIONS: Cartilage compositional MRI techniques are reliable and, in the case of T1rho and T2 relaxometry, can discriminate between subjects with OA and controls
Theoretical Constraints on the Higgs Effective Couplings
We derive constraints on the sign of couplings in an effective Higgs
Lagrangian using prime principles such as the naturalness principle, global
symmetries, and unitarity. Specifically, we study four dimension-six operators,
O_H, O_y, O_g, and O_gamma, which contribute to the production and decay of the
Higgs boson at the Large Hadron Collider (LHC), among other things. Assuming
the Higgs is a fundamental scalar, we find: 1) the coefficient of O_H is
positive except when there are triplet scalars, resulting in a reduction in the
Higgs on-shell coupling from their standard model (SM) expectations if no other
operators contribute, 2) the linear combination of O_H and O_y controlling the
overall Higgs coupling to fermion is always reduced, 3) the sign of O_g induced
by a new colored fermion is such that it interferes destructively with the SM
top contribution in the gluon fusion production of the Higgs, if the new
fermion cancels the top quadratic divergence in the Higgs mass, and 4) the
correlation between naturalness and the sign of O_gamma is similar to that of
O_g, when there is a new set of heavy electroweak gauge bosons. Next
considering a composite scalar for the Higgs, we find the reduction in the
on-shell Higgs couplings persists. If further assuming a collective breaking
mechanism as in little Higgs theories, the coefficient of O_H remains positive
even in the presence of triplet scalars. In the end, we conclude that the gluon
fusion production of the Higgs boson is reduced from the SM rate in all
composite Higgs models. Our study suggests a wealth of information could be
revealed by precise measurements of the Higgs couplings, providing strong
motivations for both improving on measurements at the LHC and building a
precision machine such as the linear collider.Comment: 37 pages, one figure; v2: improved discussion on dispersion relation
and other minor modifications; version accepted for publication
Characterisation of mechanical and thermal properties in flax fabric reinforced geopolymer composites
This paper presents the mechanical and thermal properties of flax fabric reinforced fly ash based geopolymer composites. Geopolymer composites reinforced with 2.4, 3.0 and 4.1 wt% woven flax fabric in various layers were fabricated using a hand lay-up technique and tested for mechanical properties such as flexural strength, flexural modulus, compressive strength, hardness, and fracture toughness. All mechanical properties were improved by increasing the flax fibre contents, and showed superior mechanical properties over a pure geopolymer matrix. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) studies were carried out to evaluate the composition and fracture surfaces of geopolymer and geopolymer/flax composites. The thermal behaviour of composites was studied by thermogravimetric analysis (TGA) and the results showed significant degradation of flax fibres at 300 °C
Charged hadrons in local finite-volume QED+QCD with C⋆ boundary conditions
In order to calculate QED corrections to hadronic physical quantities by means of lattice simulations, a coherent description of electrically-charged states in finite volume is needed. In the usual periodic setup, Gauss's law and large gauge transformations forbid the propagation of electrically-charged states. A possible solution to this problem, which does not violate the axioms of local quantum field theory, has been proposed by Wiese and Polley, and is based on the use of C* boundary conditions. We present a thorough analysis of the properties and symmetries of QED in isolation and QED coupled to QCD, with C* boundary conditions. In particular we learn that a certain class of electrically-charged states can be constructed in this setup in a fully consistent fashion, without relying on gauge fixing. We argue that this class of states covers most of the interesting phenomenological applications in the framework of numerical simulations. We also calculate finite-volume corrections to the mass of stable charged particles and show that these are much smaller than in non-local formulations of QED
Discovery of a bright quasar without a massive host galaxy
Quasars are thought to be powered by the infall of matter onto a supermassive
black hole at the centre of massive galaxies. As the optical luminosity of
quasars exceeds that of their host galaxy, disentangling the two components can
be difficult. This led in the 1990's to the controversial claim of the
discovery of 'naked' quasars. Since then, the connection between quasars and
galaxies has been well established. Here we report on the observation of a
quasar lying at the edge of a gas cloud, whose size is comparable to that of a
small galaxy, but whose spectrum shows no evidence for stars. The gas cloud is
excited by the quasar itself. If a host galaxy is present, it is at least six
times fainter than would normally be expected for such a bright quasar. The
quasar is interacting dynamically with a neighbouring galaxy - which matter
might be feeding the black hole.Comment: 5 figures, published in Natur
Bmcc1s, a Novel Brain-Isoform of Bmcc1, Affects Cell Morphology by Regulating MAP6/STOP Functions
The BCH (BNIP2 and Cdc42GAP Homology) domain-containing protein Bmcc1/Prune2 is highly enriched in the brain and is involved in the regulation of cytoskeleton dynamics and cell survival. However, the molecular mechanisms accounting for these functions are poorly defined. Here, we have identified Bmcc1s, a novel isoform of Bmcc1 predominantly expressed in the mouse brain. In primary cultures of astrocytes and neurons, Bmcc1s localized on intermediate filaments and microtubules and interacted directly with MAP6/STOP, a microtubule-binding protein responsible for microtubule cold stability. Bmcc1s overexpression inhibited MAP6-induced microtubule cold stability by displacing MAP6 away from microtubules. It also resulted in the formation of membrane protrusions for which MAP6 was a necessary cofactor of Bmcc1s. This study identifies Bmcc1s as a new MAP6 interacting protein able to modulate MAP6-induced microtubule cold stability. Moreover, it illustrates a novel mechanism by which Bmcc1 regulates cell morphology
Quantum surface-response of metals revealed by acoustic graphene plasmons
A quantitative understanding of the electromagnetic response of materials is essential for the precise engineering of maximal, versatile, and controllable light-matter interactions. Material surfaces, in particular, are prominent platforms for enhancing electromagnetic interactions and for tailoring chemical processes. However, at the deep nanoscale, the electromagnetic response of electron systems is significantly impacted by quantum surface-response at material interfaces, which is challenging to probe using standard optical techniques. Here, we show how ultraconfined acoustic graphene plasmons in graphene-dielectric-metal structures can be used to probe the quantum surface-response functions of nearby metals, here encoded through the so-called Feibelman d-parameters. Based on our theoretical formalism, we introduce a concrete proposal for experimentally inferring the low-frequency quantum response of metals from quantum shifts of the acoustic graphene plasmons dispersion, and demonstrate that the high field confinement of acoustic graphene plasmons can resolve intrinsically quantum mechanical electronic length-scales with subnanometer resolution. Our findings reveal a promising scheme to probe the quantum response of metals, and further suggest the utilization of acoustic graphene plasmons as plasmon rulers with angstrom-scale accuracy. Knowledge of the quantum response of materials is essential for designing light-matter interactions at the nanoscale. Here, the authors report a theory for understanding the impact of metallic quantum response on acoustic graphene plasmons and how such response could be inferred from measurements.N.A.M. is a VILLUM Investigator supported by VILLUM FONDEN (Grant No. 16498) and Independent Research Fund Denmark (Grant No. 7026-00117B). The Center for Nano Optics is financially supported by the University of Southern Denmark (SDU 2020 funding). The Center for Nanostructured Graphene (CNG) is sponsored by the Danish National Research Foundation (Project No. DNRF103). This work was partly supported by the Army Research Office through the Institute for Soldier Nanotechnologies under Contract No. W911NF-18-2-0048. N.M.R.P. acknowledges support from the European Commission through the project "Graphene-Driven Revolutions in ICT and Beyond" (No. 881603, Core 3), COMPETE 2020, PORTUGAL 2020, FEDER and the Portuguese Foundation for Science and Technology (FCT) through project POCI-01-0145-FEDER028114 and through the framework of the Strategic Financing UID/FIS/04650/2019. F.H. L.K. acknowledges financial support from the Government of Catalonia through the SGR grant and from the Spanish Ministry of Economy and Competitiveness (MINECO) through the Severo Ochoa Programme for Centres of Excellence in R&D (SEV-20150522), support by Fundacio Cellex Barcelona, Generalitat de Catalunya through the CERCA program, and the MINECO grants Plan Nacional (FIS2016-81044-P) and the Agency for Management of University and Research Grants (AGAUR) 2017 SGR 1656. Furthermore, the research leading to these results has received funding from the European Union's Horizon 2020 program under the Graphene Flagship Grant Agreements No. 785219 (Core 2) and no. 881603 (Core 3), and the Quantum Flagship Grant No. 820378. This work was also supported by the ERC TOPONANOP (Grant No. 726001)
An evaluation of classification systems for stillbirth
<p>Abstract</p> <p>Background</p> <p>Audit and classification of stillbirths is an essential part of clinical practice and a crucial step towards stillbirth prevention. Due to the limitations of the ICD system and lack of an international approach to an acceptable solution, numerous disparate classification systems have emerged. We assessed the performance of six contemporary systems to inform the development of an internationally accepted approach.</p> <p>Methods</p> <p>We evaluated the following systems: Amended Aberdeen, Extended Wigglesworth; PSANZ-PDC, ReCoDe, Tulip and CODAC. Nine teams from 7 countries applied the classification systems to cohorts of stillbirths from their regions using 857 stillbirth cases. The main outcome measures were: the ability to retain the important information about the death using the <it>InfoKeep </it>rating; the ease of use according to the <it>Ease </it>rating (both measures used a five-point scale with a score <2 considered unsatisfactory); inter-observer agreement and the proportion of unexplained stillbirths. A randomly selected subset of 100 stillbirths was used to assess inter-observer agreement.</p> <p>Results</p> <p><it>InfoKeep </it>scores were significantly different across the classifications (<it>p </it>≤ 0.01) due to low scores for Wigglesworth and Aberdeen. CODAC received the highest mean (SD) score of 3.40 (0.73) followed by PSANZ-PDC, ReCoDe and Tulip [2.77 (1.00), 2.36 (1.21), 1.92 (1.24) respectively]. Wigglesworth and Aberdeen resulted in a high proportion of unexplained stillbirths and CODAC and Tulip the lowest. While <it>Ease </it>scores were different (<it>p </it>≤ 0.01), all systems received satisfactory scores; CODAC received the highest score. Aberdeen and Wigglesworth showed poor agreement with kappas of 0.35 and 0.25 respectively. Tulip performed best with a kappa of 0.74. The remainder had good to fair agreement.</p> <p>Conclusion</p> <p>The Extended Wigglesworth and Amended Aberdeen systems cannot be recommended for classification of stillbirths. Overall, CODAC performed best with PSANZ-PDC and ReCoDe performing well. Tulip was shown to have the best agreement and a low proportion of unexplained stillbirths. The virtues of these systems need to be considered in the development of an international solution to classification of stillbirths. Further studies are required on the performance of classification systems in the context of developing countries. Suboptimal agreement highlights the importance of instituting measures to ensure consistency for any classification system.</p
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