2,423 research outputs found
Flatness optimization of micro-injection moulded parts: The case of a PMMA microfluidic component
Micro-injection moulding (µ-IM) has attracted a lot of interest because of its potential for the production of low-cost, miniaturized parts in high-volume. Applications of this technology are, amongst others, microfluidic components for lab-on-a-chip devices and micro-optical components. In both cases, the control of the part flatness is a key aspect to maintaining the component's functionality. The objective of this work is to determine the factors affecting the flatness of a polymer part manufactured by µ-IM and to control the manufacturing process with the aim of minimizing the in-process part deformation. As a case study, a PMMA microfluidic substrate with overall dimensions of 10 mm diameter and 1 mm thickness was investigated by designing a µ-IM experiment having flatness as the experimental response. The part flatness was measured using a micro-coordinate measuring machine. Finite elements analysis was also carried out to study the optimal ejection pin configuration. The results of this work show that the control of the µ-IM process conditions can improve the flatness of the polymer part up to about 15 µm. Part flatness as low as 4 µm can be achieved by modifying the design of the ejection system according to suggested guideline
Seismic vulnerability maps of Timisoara historical center based on fragility curves
The seismic vulnerability assessment on a territorial scale requires the application of simplified
procedures. Data collection is usually carried out by adopting external inspections; for this reason the
knowledge gained for the considered buildings is usually not complete and lack of information has to be managed.
The definition of a methodology which takes into account these aspects is one of the aims of this paper.
Another goal is the extension of the obtained results to buildings not directly surveyed on site, whose characteristics
are similar to those of the analyzed buildings.
The case study of Timisoara (Romania) is presented. A rapid survey of the historical center is performed and
recurring typologies are identified. Analyses of the most significant local mechanisms of collapse are implemented,
taking into account possible parameters variation. Fragility curves for each typology are then obtained
allowing the definition of vulnerability maps for the whole historical center
The Measurement of Suicide Assessment and the Development of a Treatment Strategy for Elders: Durkheim an Approach
The purpose of this study was to develop and validate Durkheim Suicide Assessment (DSA).The DSA was designed to measure suicide risk among older adults. Despite a major influence of Durkheim' theory in understanding suicide, little effort has been made to apply such theory in gerontological practice. Data were drawn from a survey of 380 older adults over the age of 65. Principal component analysis was conducted with the 80 items of the original DSA, which yielded the 26 items of the DSA. Furthermore we performed explore factor analyses to assess the factor structures of the DSA. Internal consistency reliability was examined using Cronbach's alpha. The results show that the DSA is a psychometrically sound measurement. Health care professionals can use the DSA to assess suicide potential and develop an effective treatment strategy based on the type of suicide in which the elder has the highest probability of pursuing
Multi-wavelength visibility measurements of the red giant R Doradus
We present visibility measurements of the nearby Mira-like star R Doradus
taken over a wide range of wavelengths (650--990 nm). The observations were
made using MAPPIT (Masked APerture-Plane Interference Telescope), an
interferometer operating at the 3.9-m Anglo-Australian Telescope. We used a
slit to mask the telescope aperture and prism to disperse the interference
pattern in wavelength. We observed in R Dor strong decreases in visibility
within the TiO absorption bands. The results are in general agreement with
theory but differ in detail, suggesting that further work is needed to refine
the theoretical models.Comment: 8 pages; SPIE Conf. 4006 "Interferometry in Optical Astronomy
Cationic carbosilane dendrimers and oligonucleotide binding: an energetic affair
GENERATION 2 CATIONIC CARBOSILANE DENDRIMERS HOLD GREAT PROMISE AS INTERNALIZING AGENTS FOR GENE THERAPY AS THEY PRESENT LOW TOXICITY AND RETAIN AND INTERNALIZE GENETIC MATERIAL AS OLIGONUCLEOTIDE OR SIRNA. IN THIS WORK WE CARRIED OUT A COMPLETE IN SILICO STRUCTURAL AND ENERGETICAL CHARACTERIZATION OF THE INTERACTIONS OF A SET OF 2G CARBOSILANE DENDRIMERS, SHOWING DIFFERENT AFFINITY TOWARDS TWO SINGLE STRAND OLIGONUCLEOTIDE (ODN) SEQUENCES IN VITRO. OUR SIMULATIONS PREDICT THAT THESE FOUR DENDRIMERS AND THE RELEVANT ODN COMPLEXES ARE CHARACTERIZED BY SIMILAR SIZE AND SHAPE, AND THAT THE MOLECULE-SPECIFIC ODN BINDING ABILITY CAN BE RATIONALIZED ONLY CONSIDERING A CRITICAL MOLECULAR DESIGN PARAMETER: THE NORMALIZED EFFECTIVE BINDING ENERGY \u394GBIND,EFF/NEFF I.E., THE PERFORMANCE OF EACH ACTIVE INDIVIDUAL DENDRIMER BRANCH DIRECTLY INVOLVED IN A BINDING INTERACTIO
Towards Bidirectional Ratcheted Key Exchange
Ratcheted key exchange (RKE) is a cryptographic technique used in instant messaging systems like Signal and the WhatsApp messenger for attaining strong security in the face of state exposure attacks. RKE received academic attention in the recent works of Cohn-Gordon et al. (EuroS&P 2017) and Bellare et al. (CRYPTO 2017). While the former is analytical in the sense that it aims primarily at assessing the security that one particular protocol does achieve (which might be weaker than the notion that it should achieve), the authors of the latter develop and instantiate a notion of security from scratch, independently of existing implementations. Unfortunately, however, their model is quite restricted, e.g. for considering only unidirectional communication and the exposure of only one of the two parties.In this article we resolve the limitations of prior work by developing alternative security definitions, for unidirectional RKE as well as for RKE where both parties contribute. We follow a purist approach, aiming at finding strong yet convincing notions that cover a realistic communication model with fully concurrent operation of both participants. We further propose secure instantiations (as the protocols analyzed or proposed by Cohn-Gordon et al. and Bellare et al. turn out to be weak in our models). While our scheme for the unidirectional case builds on a generic KEM as the main building block (differently to prior work that requires explicitly Diffie–Hellman), our schemes for bidirectional RKE require a stronger, HIBE-like component
Topiramate versus carbamazepine monotherapy for epilepsy: an individual participant data review.
Epilepsy is a common neurological condition in which abnormal electrical discharges from the brain cause recurrent unprovoked seizures. It is believed that with effective drug treatment, up to 70% of individuals with active epilepsy have the potential to become seizure-free and go into long-term remission shortly after starting drug therapy, the majority of which may be able to achieve remission with a single antiepileptic drug (AED).The correct choice of first-line antiepileptic therapy for individuals with newly diagnosed seizures is of great importance. It is important that the choice of AED for an individual is based on the highest-quality evidence available regarding the potential benefits and harms of various treatments. It is also important to compare the efficacy and tolerability of AEDs appropriate to given seizure types.Topiramate and carbamazepine are commonly used AEDs. Performing a synthesis of the evidence from existing trials will increase the precision of results of outcomes relating to efficacy and tolerability, and may help inform a choice between the two drugs.To assess the effects of topiramate monotherapy versus carbamazepine monotherapy for epilepsy in people with partial-onset seizures (simple or complex partial and secondarily generalised) or generalised onset tonic-clonic seizures (with or without other generalised seizure types).We searched the Cochrane Epilepsy Group Specialized Register (14 April 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) (14 April 2016) and MEDLINE (Ovid, 1946 to 14 April 2016). We imposed no language restrictions. We also contacted pharmaceutical companies and trial investigators.Randomised controlled trials in children or adults with partial-onset seizures or generalised-onset tonic-clonic seizures with or without other generalised seizure types with a comparison of monotherapy with either topiramate or carbamazepine.This was an individual participant data (IPD) review. Our primary outcome was 'time to withdrawal of allocated treatment', and our secondary outcomes were 'time to first seizure post randomisation', 'time to 6-month remission, 'time to 12-month remission' and incidence of adverse events. We used Cox proportional hazards regression models to obtain trial-specific estimates of hazard ratios (HRs) with 95% confidence intervals (CIs), and used the generic inverse variance method to obtain the overall pooled HRs and 95% CIs.IPD were available for 1151 of 1239 eligible individuals from two of three eligible studies (93% of the potential data). A small proportion of individuals recruited into these trials had 'unclassified seizures;' for analysis purposes, these individuals are grouped with those with generalised onset seizures. For remission outcomes, a HR < 1 indicated an advantage for carbamazepine, and for first seizure and withdrawal outcomes, a HR < 1 indicated an advantage for topiramate.The main overall results, given as pooled HR adjusted for seizure type (95% CI) were: for time to withdrawal of allocated treatment 1.16 (0.98 to 1.38); time to first seizure 1.11 (0.96 to 1.29); and time to 6-month remission 0.88 (0.76 to 1.01). There were no statistically significant differences between the drugs. A statistically significant advantage for carbamazepine was shown for time to 12-month remission: 0.84 (0.71 to 1.00).The results of this review are applicable mainly to individuals with partial-onset seizures; 85% of included individuals experienced seizures of this type at baseline. For individuals with partial-onset seizures, a statistically significant advantage for carbamazepine was shown for time to withdrawal of allocated treatment (HR 1.20, 95% CI 1.00 to 1.45) and time to 12-month remission (HR 0.84, 95% CI 0.71 to 1.00). No statistically significant differences were apparent between the drugs for other outcomes and for the limited number of individuals with generalised-onset tonic-clonic seizures with or without other generalised seizure types or unclassified seizures.The most commonly reported adverse events with both drugs were drowsiness or fatigue, 'pins and needles' (tingling sensation), headache, gastrointestinal disturbance and anxiety or depression The rate of adverse events was similar across the two drugs.We judged the methodological quality of the included trials generally to be good; however, there was some evidence that the open-label design of the larger of the two trials may have influenced the withdrawal rate from the trial. Hence, we judged the evidence for the primary outcome of treatment withdrawal to be moderate for individuals with partial-onset seizures and low for individuals with generalised-onset seizures. For efficacy outcomes (first seizure, remission), we judged the evidence from this review to be high for individuals with partial-onset seizures and moderate for individuals with generalised-onset or unclassified seizures.For individuals with partial-onset seizures, there is evidence that carbamazepine is less likely to be withdrawn and that 12-month remission will be achieved earlier than with topiramate. No differences were found between the drugs in terms of the outcomes measured in the review for individuals with generalised tonic-clonic seizures with or without other seizure types or unclassified epilepsy; however, we encourage caution in the interpretation of these results due to the small numbers of participants with these seizure types.We recommend that future trials should be designed to the highest quality possible and take into consideration masking, choice of population, classification of seizure type, duration of follow-up, choice of outcomes and analysis, and presentation of results
Qualitative study of paramedics' experiences of managing seizures: A national perspective from England
Objectives: The UK ambulance service is expected to now manage more patients in the community and avoid unnecessary transportations to hospital emergency departments (ED). Most people it attends who have experienced seizures have established epilepsy, have experienced uncomplicated seizures and so do not require the full facilities of an ED. Despite this, most are transported there. To understand why, we explored paramedics experiences of managing seizures. Design and setting: Semistructured interviews were conducted with a purposive sample of paramedics from the English ambulance service. Interviews were transcribed and thematically analysed. Participants: A diverse sample of 19 professionals was recruited from 5 different ambulance NHS trusts and the College of Paramedics. Results: Participants confirmed how most seizure patients attended to do not clinically require an ED. They explained, however, that a number of factors influence their care decisions and create a momentum for these patients to still be taken. Of particular importance was the lack of access paramedics have to background medical information on patients. This, and the limited seizure training paramedics receive, meant paramedics often cannot interpret with confidence the normality of a seizure presentation and so transport patients out of precaution. The restricted time paramedics are expected to spend on scene due to the way the ambulance services performance is measured and that are few alternative care pathways which can be used for seizure patients also made conveyance likely. Conclusions: Paramedics are working within a system that does not currently facilitate nonconveyance of seizure patients. Organisational, structural, professional and educational factors impact care decisions and means transportation to ED remains the default option. Improving paramedics access to medical histories, their seizure management training and developing performance measures for the service that incentivise care that is cost-effective for all of the health service might reduce unnecessary conveyances to ED
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