27,522 research outputs found
Multidimensional en-face OCT imaging of the retina.
Fast T-scanning (transverse scanning, en-face) was used to build B-scan or C-scan optical coherence tomography (OCT) images of the retina. Several unique signature patterns of en-face (coronal) are reviewed in conjunction with associated confocal images of the fundus and B-scan OCT images. Benefits in combining T-scan OCT with confocal imaging to generate pairs of OCT and confocal images similar to those generated by scanning laser ophthalmoscopy (SLO) are discussed in comparison with the spectral OCT systems. The multichannel potential of the OCT/SLO system is demonstrated with the addition of a third hardware channel which acquires and generates indocyanine green (ICG) fluorescence images. The OCT, confocal SLO and ICG fluorescence images are simultaneously presented in a two or a three screen format. A fourth channel which displays a live mix of frames of the ICG sequence superimposed on the corresponding coronal OCT slices for immediate multidimensional comparison, is also included. OSA ISP software is employed to illustrate the synergy between the simultaneously provided perspectives. This synergy promotes interpretation of information by enhancing diagnostic comparisons and facilitates internal correction of movement artifacts within C-scan and B-scan OCT images using information provided by the SLO channel
Physical space description of decorated quasicrystals
In this paper the systematic method of dealing with the arbitrary decorations
of quasicrystals is presented. The method is founded on the average unit cell
formalism and operates in the physical space only, where each decorating atom
manifests itself just by an additional component of the displacement density
function in the average unit cell. Such approach allows us to use almost all
classical crystallography algorithms for structure refining based on
experimental data and may meaningly decrease the number of parameters which
have to be fit. Further help for such analysis may be the use of proposed
recently average Patterson function, here applied to decorated sets. As an
example we present a description of a class of decorated quasicrystals based on
Sturmian sequence of two interatomic spacings: we calculate explicitly
structure factor, the shape of average Patterson function and give an algorithm
for pattern analysis.Comment: 17 pages, 5 figure
Distribution of skates and sharks in the North Sea: 112 years of change
How have North Sea skate and shark assemblages changed since the early 20th century when bottom trawling became widespread, whilst their environment became increasingly impacted by fishing, climate change, habitat degradation and other anthropogenic pressures? This article examines long-term changes in the distribution and occurrence of the elasmobranch assemblage of the southern North Sea, based on extensive historical time series (1902–2013) of fishery-independent survey data. In general, larger species (thornback ray, tope, spurdog) exhibited long-term declines, and the largest (common skate complex) became locally extirpated (as did angelshark). Smaller species increased (spotted and starry ray, lesser-spotted dogfish) as did smooth-hound, likely benefiting from greater resilience to fishing and/or climate change. This indicates a fundamental shift from historical dominance of larger, commercially valuable species to current prevalence of smaller, more productive species often of low commercial value. In recent years, however, some trends have reversed, with the (cold-water associated) starry ray now declining and thornback ray increasing. This shift may be attributed to (i) fishing, including mechanised beam trawling introduced in the 1960s–1970s, and historical target fisheries for elasmobranchs; (ii) climate change, currently favouring warm-water above cold-water species; and (iii) habitat loss, including potential degradation of coastal and outer estuarine nursery habitats. The same anthropogenic pressures, here documented to have impacted North Sea elasmobranchs over the past century, are likewise impacting shelf seas worldwide and may increase in the future; therefore, parallel changes in elasmobranch communities in other regions are to be expected
Nephrectomy for a case of intrarenal dermoid cyst: was it an appropriate decision?
Dermoid cyst in a kidney is rarely seen. We report a case of intrarenal dermoid cyst which mimics malignant renal tumour and discuss the dilemma in managing this disease
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Study on thermal conductivity of gas phase in nano-porous aerogel
This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Nano-porous aerogel has an ultra low thermal conductivity and is usually used as the super
insulator. To evaluate the insulation performance of the aerogel, we focus on studying the thermal
conductivity of gas phase in the aerogel. We present a modified model to take into account the effect of nonuniform
pore-size distribution on the gaseous thermal conductivity, and the present model predicts more
agreement results with available data than the existing models. The gaseous thermal conductivity of the
aerogel at high temperature gradient condition is also numerically studied. We also study the effect of the
thermal transpiration flow on the gaseous thermal conductivity, and the results shows that the thermal
transpiration flow effect leads to a reduction of the gaseous thermal conductivity
Qualitative and quantitative changes of essential composition in the flowers of some populations of Elaeagnus angustifolia
Background and aims: Elaeagnus angustifolia L. is a member of the Elaeagaceae family; different parts of it, especially fruits have been used for the treatment of several diseases in traditional medicine. The aim of this study was to isolate and determine essential oil composition of flowers of E. angustifolia collected from different ecological areas of East-Azarnayjan in Iran. Methods: In this experimental study, the essential oils of the flower were isolated by hydrodistillation method and analyzed by GC and GC/MS. Results: The number of compounds in the essential oil isolated from the population of Ahar, Marand and Hashtroud were 22, 17 and 14, respectively. The major component of all of the populations was ethylcinnamate; Ahar (47.59), Marand (69.99) and Hashtroud (85.49). It was observed that the oil number of E. angustifolia decreases from 22 to 14 when the altitude increases from 1344-1750 m. Conclusion:Chemical composition of the essential oils of E. angustifolia L. such as esters and aromatic acids contents were increased while the ketone content was decreased with increasing altitude
Common fixed point theorems in modular G-metric spaces
The purpose of this paper is to prove the existence of the unique common fixed point theorems of a pair of weakly compatible mappings satisfying -maps in modular G-metric spaces
The effect of Satureja khuzestanica on triglyceride, glucose, creatinine and alkaline phosphatase activity in rat
زمینه و هدف: مرزه یا ساتوریا خوزستانیکا (Satureja khuzestanica) از گیاهان بومی ایران می باشد که به طور گسترده ای در نواحی جنوبی کشور به ویژه استان لرستان وجود دارد و در طب سنتی دارای مصارف پزشکی، از جمله فعالیت ضد درد و عفونت می باشد. در مطالعات قبلی مشاهده گردید که این گیاه باعث کاهش معنی دار وزن در موشهای مورد آزمایش شده است. بر همین اساس بر آن شدیم اثرات دم کرده و اسانس روغنی این گیاه را روی وزن بدن، دریافت غذا و فاکتورهای لیپیدی، قندی، پروتئینی، الکترولیت ها و آنزیم های کبدی در رت بررسی کنیم. روش بررسی: این مطالعه تجربی است که در سال 1382 در مرکز تحقیقات گیاهان دارویی دانشگاه علوم پزشکی لرستان انجام شد. دم کرده گیاه مزبور به مقادیر 75، 150 و 250 میلی گرم بر کیلوگرم از راه خوراکی به مدت سه هفته به ترتیب برای حیوانات در سه گروه تجویز شد و در گروه چهارم، اسانس روغنی گیاه در آب خوراکی به میزانppm 1000 حل و تجویز گردید. در عین حال برای گروه کنترل هیچگونه گیاهی تجویز نشد. وزن حیوانات و میزان دریافت آب و غذای آنها بصورت روزانه ثبت گردید و در پایان 3 هفته فاکتورهای خونی و آنزیم های کبدی در سرم این حیوانات اندازه گیری شد. داده ها با آزمون ANOVA یکطرفه و بدنبال آن آزمون Tukey با یکدیگر مقایسه گردید و در بعضی گروهها که توزیع داده ها نرمال نبود از آزمون من ویتنی استفاده شد. یافته ها: میزان تری گلیسرید سرمی در گروه اسانس روغنی )92/3±15/43 میلی گرم بر دسی لیتر) نسبت به گروه کنترل (03/8±99/89 میلی گرم بر دسی لیتر) تفاوت معنی دار داشت (001/0
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Parameter estimation for a morphochemical reaction-diffusion model of electrochemical pattern formation
The process of electrodeposition can be described in terms of a reaction-diffusion PDE system that models the dynamics of the morphology profile and the chemical composition. Here we fit such a model to the different patterns present in a range of electrodeposited and electrochemically modified alloys using PDE constrained optimization. Experiments with simulated data show how the parameter space of the model can be divided into zones corresponding to the different physical patterns by examining the structure of an appropriate cost function. We then use real data to demonstrate how numerical optimization of the cost function can allow the model to fit the rich variety of patterns arising in experiments. The computational technique developed provides a potential tool for tuning experimental parameters to produce desired patterns
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