Simulation studies of Non-Ionising Energy Loss (NIEL) in silicon exposed to various types of hadron irradiation are presented. A simulation model of migration and clustering of the produced primary ...defects is developed. Although there are many uncertainties in the input parameters it is shown that the model is consistent with experimental observations on standard and oxygen-enriched silicon. However, the model makes the rather dramatic prediction that NIEL scaling of leakage current and effective doping concentration can be violated significantly even in standard silicon. Although there are possible shortcomings in the model which might account for this, it is shown that at the microscopic level there is, indeed, no obvious reason for an exact NIEL scaling. Furthermore, it is argued that, contrary to common belief, even a significant violation of NIEL scaling can still be consistent with experimental data.
The aim of this randomised, double-blind, placebo-controlled, clinical-field study was to evaluate the effect of dexmedetomidine oromucosal gel at subsedative doses in alleviation of noise-associated ...acute anxiety and fear in dogs. On New Year's Eve, 182 dogs with a history of acute anxiety and fear associated with fireworks received treatment as needed up to five times: 89 dogs received dexmedetomidine and 93 dogs received placebo. For the primary efficacy variables, dog owners assessed the overall treatment effect as well as signs and extent of anxiety and fear. The overall treatment effect was statistically significant (P<0.0001). An excellent or good treatment effect was reported for a higher proportion of dogs treated with dexmedetomidine (64/89, 72 per cent) than those receiving placebo (34/93, 37 per cent). Additionally, dexmedetomidine-treated dogs expressed significantly (P<0.0314) fewer signs of fear and anxiety despite the noise of fireworks. No local tolerance or clinical safety concerns occurred during the study. This study demonstrated that oromucosal dexmedetomidine at subsedative doses alleviates noise-associated acute anxiety and fear in dogs.
One source of experimental background in the CERN Large Hadron Collider (LHC) is particles entering the detectors from the machine. These particles are created in cascades, caused by upstream ...interactions of beam protons with residual gas molecules or collimators. We estimate the losses on the collimators with SixTrack and simulate the showers with FLUKA and MARS to obtain the flux and distribution of particles entering the ATLAS and CMS detectors. We consider some machine configurations used in the first LHC run, with focus on 3.5TeV operation as in 2011. Results from FLUKA and MARS are compared and a very good agreement is found. An analysis of logged LHC data provides, for different processes, absolute beam loss rates, which are used together with further simulations of vacuum conditions to normalize the results to rates of particles entering the detectors. We assess the relative importance of background from elastic and inelastic beam–gas interactions, and the leakage out of the LHC collimation system, and show that beam–gas interactions are the dominating source of machine-induced background for the studied machine scenarios. Our results serve as a starting point for the experiments to perform further simulations in order to estimate the resulting signals in the detectors.
•We simulate sources of machine-induced experimental background at the CERN LHC.•We focus on the ATLAS and CMS experiments.•The LHC machine conditions are analyzed to normalize the simulation results.•Beam–gas interactions is found to be the dominating source of particles entering the detectors.
Background
There is an unmet clinical need for a cat‐specific formulation of amlodipine to treat hypertensive cats.
Objectives
To assess the efficacy of chewable amlodipine tablets in reducing ...systolic blood pressure (SBP) in cats diagnosed with systemic arterial hypertension.
Animals
Seventy‐seven client‐owned cats with systemic hypertension were included (median age 14 years).
Methods
The study was randomized, double‐blinded, and placebo‐controlled. Forty‐two cats received 0.125–0.50 mg/kg amlodipine once daily for 28 days; 35 cats received placebo. After 28 days all cats continued with amlodipine for 2–3 months in an open‐label phase. Blood pressure was measured using high definition oscillometry. A responder was defined as a cat showing a decrease of SBP to <150 mmHg at 28 days or a decrease from baseline ≥15%.
Results
Sixty‐one cats completed the study. The responder rate was 63% in amlodipine group and 18% in placebo group. Cats receiving amlodipine were 7.9 (95% CI 2.6–24.1) times more likely to be classified as responders when compared to those receiving placebo (P < .001). From a mean (±SD) baseline value of 181 (±12) mmHg, SBP decreased to 154 (±17) mmHg with amlodipine and to 170 (±21) mmHg with placebo (P < .001). The voluntary acceptance rate of amlodipine formulation was 73%.
Conclusions and Clinical Importance
The chewable amlodipine tablet effectively reduced SBP compared with placebo in hypertensive cats, and was well‐tolerated. It can be used concomitantly with angiotensin‐converting enzyme inhibitors and in cats with chronic kidney disease.
The data produced at the particle physics experiments at the Large Hadron Collider (LHC) contain not only the signals from the collisions, but also a background component from proton losses around ...the accelerator. Understanding, identifying and possibly mitigating this machine-induced background is essential for an efficient data taking, especially for some new physics searches. Among the sources of background are hadronic and electromagnetic showers from proton losses on nearby collimators due to beam-halo cleaning. In this article, the first dedicated LHC measurements of this type of background are presented. Controlled losses of a low-intensity beam on collimators were induced, while monitoring the backgrounds in the ATLAS detector. The results show a clear correlation between the experimental backgrounds and the setting of the tertiary collimators (TCTs). Furthermore, the results are used to show that during normal LHC physics operation the beam halo contributes to the total beam-induced background at the level of a percent or less. A second measurement, where the collimator positions are tightened during physics operation, confirms this finding by setting a limit of about 10% to the contribution from all losses on the TCTs, i.e. the sum of beam halo and elastic beam-gas scattering around the ring. Dedicated simulations of the halo-related background are presented and good agreement with data is demonstrated. These simulations provide information about features that are not experimentally accessible, like correlations between backgrounds and the distributions of proton impacts on the collimators. The results provide vital information about the dependence between background and collimator settings, which is of central importance when optimizing the LHC optics for maximum peak luminosity.
We discuss the physics potential and the experimental challenges of an upgraded LHC running at an instantaneous luminosity of 1035 cm-2s-1. The detector R&D needed to operate ATLAS and CMS in a very ...high radiation environment and the expected detector performance are discussed. A few examples of the increased physics potential are given, ranging from precise measurements within the Standard Model (in particular in the Higgs sector) to the discovery reach for several New Physics processes.
We present a new method to estimate Single Event Upsets (SEU) in a hadron accelerator environment, which is characterized by a complicated radiation spectrum. Our method is based on first principles, ...i.e. an explicit generation and transport of nuclear fragments and detailed accounting for energy loss by ionization. However, instead of simulating also the behaviour of the circuit, we use a Weibull fit to experimental heavy-ion SEU data in order to quantify the SEU sensitivity of the circuit. Thus, in principle, we do not need to know details about the circuit and our method is almost free of adjustable parameters – we only need a reasonable guess for the Sensitive Volume (SV) size. We show by a comparison with experimental data that our method predicts the SEU cross sections for protons rather accurately. We then indicate with an example how our method could be applied to predict SEU rates at the forthcoming LHC experiments.
Alpha
2 agonist-induced pulmonary oedema in sheep might be related to alterations in pulmonary haemodynamics and/or activation of inflammatory processes. In seven sevoflurane-anaesthetized sheep ...pulmonary haemodynamics, arterial oxygen tensions, nitric oxide and prostaglandin E
2 concentrations were determined before and after intravenous dexmedetomidine (2
μg
kg
−1). In a second trial, lung tissue was sampled for histopathology and quantitative real-time PCR for IL-1β and iNOS mRNA in a control sheep and 2, 10 and 30
min after dexmedetomidine. Computer tomography of the lung under sevoflurane anaesthesia before and after dexmedetomidine was performed.
Two minutes after dexmedetomidine mean pulmonary artery pressure, pulmonary arterial occlusion pressure and estimated capillary pressurewere significantly increased to 34.5
mmHg, 22.2
mmHg and 27.1
mmHg, respectively. On computer tomography, lung density increased immediately after dexmedetomidine, with maximal density occurring between 9 and 12
min. Histopathology was consistent with vascular congestion followed by protein and erythrocyte extravasation into alveoli. Increased iNOS mRNA levels were detected in sevoflurane anaesthetized animals only. An IL-1β signal occurred after morphological changes had occurred in lung tissue.
These findings support hydrostatic stress as the underlying cause of alpha
2 agonist-induced pulmonary oedema in sheep.
AIMS To determine whether HLA-B27 typing helps the clinician in the diagnostic examination of uveitis in a HLA-B27 rich population and also whether the clinical picture of HLA-B27 positive unilateral ...acute or recurrent anterior uveitis (AAU) is distinguishable from the idiopathic negative form. METHODS During a 3 year period 220 consecutive patients with undetermined uveitis at onset were examined in the Helsinki University Eye Clinic. HLA-B27 antigen was tested for 85% of the patients. Other laboratory or x ray examinations were performed on the basis of the anatomical classification of uveitis and the biomicroscopic features characteristic of uveitis associated systemic diseases. RESULTS HLA-B27 antigen was found significantly more often in patients with anterior (71%) and acute/recurrent unilateral (79%) uveitis than in patients with intermediate, posterior panuveitis (7%), and chronic (7%) or bilateral (12%) forms. Of the 16 cases of HLA-B27 negative unilateral AAU, five showed biomicroscopic features representing uveitis entities. The remaining 11 cases did not differ in any respect from the cases of HLA-B27 positive unilateral AAU. CONCLUSION HLA-B27 antigen helps the clinician in the diagnostic examination of unilateral AAU. Positive test results serve as a clue to search for spondyloarthropathies, and negative results indicate the need to look for specific uveitis entities and other systemic diseases. The occurrence of HLA-B27 positivity in conjunction with uveitis entities other than unilateral AAU is of the same level or less than in the population of Finland in general.
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