5,806 research outputs found
Achieving hip fracture surgery within 36 hours: an investigation of risk factors to surgical delay and recommendations for practice
BACKGROUND: The UK hip fracture best practice tariff (BPT) aims to deliver hip fracture surgery within 36 h of admission. Ensuring that delays are reserved for conditions which compromise survival, but are responsive to medical optimisation, would help to achieve this target. We aimed to identify medical risk factors of surgical delay, and assess their impact on mortality. MATERIALS AND METHODS: Prospectively collected patient data was obtained from the National Hip Fracture Database (NHFD). Medical determinants of surgical delay were identified and analysed using a multivariate regression analysis. The mortality risk associated with each factor contributing to surgical delay was then calculated. RESULTS: A total 1361 patients underwent hip fracture surgery, of which 537 patients (39.5 %) received surgery within 36 h of admission. Following multivariate analyses, only hyponatraemia was deduced to be a significant risk factor for delay RR = 1.24 (95 % CI 1.06-1.44). However, following a validated propensity score matching process, a Pearson chi-square test failed to demonstrate a statistical difference in mortality incidence between the hypo- and normonatraemic patients [χ (2) (1, N = 512) = 0.10, p = 0.757]. CONCLUSIONS: Hip fracture surgery should not be delayed in the presence of non-severe and isolated hyponatraemia. Instead, surgical delay may only be warranted in the presence of medical conditions which contribute to mortality and are optimisable. LEVEL OF EVIDENCE: III
Magnetic Transition in the Kondo Lattice System CeRhSn2
Our resistivity, magnetoresistance, magnetization and specific heat data
provide unambiguous evidence that CeRhSn2 is a Kondo lattice system which
undergoes magnetic transition below 4 K.Comment: 3 pages text and 5 figure
Inter-organisational coordination of H1N1 outbreak: data collection, and analyses of a pilot field study
Improving effectiveness in response to H1N1 outbreaks requires us to understand how different organisations within the outbreak coordination network work collectively to share information needed to operate at optimal level. Research for developing reliable framework for the collection of inter-organisational coordinated response data and its impact on decision-making and support system for disease outbreak is lacking to date. We introduce a pilot field study using social networks based approach to capture H1N1 inter-organisational coordination data by introducing qualitative questionnaire and quantitative survey, which resulted in discovering the hidden social networks of coordination. Here, we propose a schema that can be used to classify the quantitative data collection and preparation for further empirical analysis, and suggest that lessons learned from this can be applied to explore possible data collection and analysis for other types of natural and man made crises.postprin
Dirac Point and Edge States in a Microwave Realization of Tight-Binding Graphene-like Structures
We present a microwave realization of finite tight-binding graphene-like
structures. The structures are realized using discs with a high index of
refraction. The discs are placed on a metallic surface while a second surface
is adjusted atop the discs, such that the waves coupling the discs in the air
are evanescent, leading to the tight-binding behavior. In reflection
measurements the Dirac point and a linear increase close to the Dirac point is
observed, if the measurement is performed inside the sample. Resonances due to
edge states are found close to the Dirac point if the measurements are
performed at the zigzag-edge or at the corner in case of a broken benzene ring.Comment: 4 pages, 6 figure
Total chemical synthesis of a heterodimeric interchain Bis-Lactam-linked peptide: application to an analogue of human insulin-like peptide 3
Nonreducible cystine isosteres represent important peptide design elements in that they can maintain a near-native tertiary conformation of the peptide while simultaneously extending the in vitro and in vivo half-life of the biomolecule. Examples of these cystine mimics include dicarba, diselenide, thioether, triazole, and lactam bridges. Each has unique physicochemical properties that impact upon the resulting peptide conformation. Each also requires specific conditions for its formation via chemical peptide synthesis protocols. While the preparation of peptides containing two lactam bonds within a peptide is technically possible and reported by others, to date there has been no report of the chemical synthesis of a heterodimeric peptide linked by two lactam bonds. To examine the feasibility of such an assembly, judicious use of a complementary combination of amine and acid protecting groups together with nonfragment-based, total stepwise solid phase peptide synthesis led to the successful preparation of an analogue of the model peptide, insulin-like peptide 3 (INSL3), in which both of the interchain disulfide bonds were replaced with a lactam bond. An analogue containing a single disulfide-substituted interchain lactam bond was also prepared. Both INSL3 analogues retained significant cognate RXFP2 receptor binding affinity.John Karas, Fazel Shabanpoor, Mohammed Akhter Hossain, James Gardiner, Frances Separovic, John D. Wade and Denis B. Scanlo
Background independent quantization and the uncertainty principle
It is shown that polymer quantization leads to a modified uncertainty
principle similar to that obtained from string theory and non-commutative
geometry. When applied to quantum field theory on general background
spacetimes, corrections to the uncertainty principle acquire a metric
dependence. For Friedmann-Robertson-Walker cosmology this translates to a scale
factor dependence which gives a large effect in the early universe.Comment: 6 page
Sex Variability in Pediatric Leukemia Survival: Large Cohort Evidence
Purpose. Sex disparities in pediatric leukemia have been previously reported, and male children continue to present with poorer survival. However, the observed disparities are not fully understood. This current study sought to examine disparities in survival by the sex, and to determine if tumor prognostic factors impact on these disparities. Patients and Methods. We used the Surveillance Epidemiology and End Results dataset of pediatric leukemia patients (ages 0–19 years) diagnosed in the United States from 1973 to 2006. There were 15,215 patients of whom 8,622 (65.7%) were boys and 6,593 (43.3%) were girls. The Kaplan-Meier survival estimates, log rank test, and Cox proportional hazard methods were used to assess the data. Results. The overall (both sexes) five-year survival rate was 67.9%. Girls had a survival rate of 70.1%, while the rate was 66.3% in boys. Girls had a significant 14% decreased risk of dying relative to boys, hazard ratio (HR) = 0.86, 99% CI = 0.80–0.93. There were significant differences between boys and girls with respect to tumor cell type, race, age at diagnosis, year of diagnosis, and number of primaries, P < 0.001. After controlling for these factors, the sex differences in survival persisted, with girls still less likely to die from leukemia compared to boys, adjusted HR (AHR) = 0.85, 99% CI = 0.72–1.00, P < 0.01. Conclusion. In a large population-based pediatric leukemia study, boys continued to show poorer survival. These disparities were not completely explained by treatment received, tumor prognostic or socio-demographic factors
Modeling galactic halos with predominantly quintessential matter
This paper discusses a new model for galactic dark matter by combining an
anisotropic pressure field corresponding to normal matter and a quintessence
dark energy field having a characteristic parameter such that
. Stable stellar orbits together with an attractive
gravity exist only if is extremely close to , a result
consistent with the special case studied by Guzman et al. (2003). Less
exceptional forms of quintessence dark energy do not yield the desired stable
orbits and are therefore unsuitable for modeling dark matter.Comment: 12 pages, 1 figur
An analysis on decentralized adaptive MAC protocols for Cognitive Radio networks
The scarcity of bandwidth in the radio spectrum has become more vital since the demand for more and more wireless applications has increased. Most of the spectrum bands have been allocated although many studies have shown that these bands are significantly underutilized most of the time. The problem of unavailability of spectrum and inefficiency in its utilization has been smartly addressed by the Cognitive Radio (CR) Technology which is an opportunistic network that senses the environment, observes the network changes, and then using knowledge gained from the prior interaction with the network, makes intelligent decisions by dynamically adapting their transmission characteristics. In this paper some of the decentralized adaptive MAC protocols for CR networks have been critically analyzed and a novel adaptive MAC protocol for CR networks, DNG-MAC which is decentralized and non-global in nature, has been proposed. The results show the DNG-MAC out performs other CR MAC protocols in terms of time and energy efficiency
Two Gaps Make a High Temperature Superconductor?
One of the keys to the high-temperature superconductivity puzzle is the
identification of the energy scales associated with the emergence of a coherent
condensate of superconducting electron pairs. These might provide a measure of
the pairing strength and of the coherence of the superfluid, and ultimately
reveal the nature of the elusive pairing mechanism in the superconducting
cuprates. To this end, a great deal of effort has been devoted to investigating
the connection between the superconducting transition temperature Tc and the
normal-state pseudogap crossover temperature T*. Here we present a review of a
large body of experimental data that suggests a coexisting two-gap scenario,
i.e. superconducting gap and pseudogap, over the whole superconducting dome.Comment: Related material can be found at
http://www.physics.ubc.ca/~quantmat/ARPES/PUBLICATIONS/articles.htm
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