Multiple Spots Research Articles

Blind After a Binge: Purtscher-like Retinopathy in Acute Alcoholic Pancreatitis

ABSTRACTPurtscher-like retinopathy is an occlusive microvasculopathy that causes sudden onset vision loss of varying severity. The condition is a rare complication of acute pancreatitis and is scarcely documented in the literature. In addition, it is vision-threatening, and there are no evidence-based therapies available. We report a 37-year-old woman presenting with abdominal pain and nausea in the setting of heavy alcohol use. She was diagnosed with acute pancreatitis. During hospitalization, she developed acute visual disturbance and was found to have significantly diminished visual acuity. A dilated funduscopic examination demonstrated multiple retinal cotton wool spots bilaterally and macular edema. The patient was diagnosed with Purtscher-like retinopathy in the setting of acute pancreatitis. Although the prognosis for her vision was guarded, given the ischemic nature of the insult, she had subjective improvement in visual acuity during the remainder of the hospital course with symptomatic management.

Alopecia universalis successfully treated with kenchuto groups in a pediatric patient

ABSTRACTCaseThe patient was an initially healthy girl aged 1 year and 5 months. She developed alopecia when she was 11 months old. At hospital visit, she was found to have alopecia universalis. Her hands and feet were cold, and her nails appeared dry.OutcomeHer symptoms were considered to indicate blood deficiency, and she received tokikenchuto. Six months later, multiple spots of alopecia were noted. Nine months later, the alopecia spots decreased and her nails were normalized and we changed tokikenchuto to shokenchuto. One year and 7 months later, the alopecia spots were no longer prominent.ConclusionFor alopecia in children, regional immunotherapy has been recommended in the treatment guidelines. However, the condition can recur after discontinuation of treatment and there is no treatment uniformity. The present findings suggest that Kampo medicine might be appropriate for alopecia universalis considering treatment continuity and safety.

Quantitative and qualitative evaluation of recovery process of a 1064 nm laser on laser-induced skin injury: in vivo experimental research

Laser biological effects are a hot topic in laser medicine. In this study, to explore the quantitative biological effect of laser-induced wound healing and to provide guidance for expanding the clinical application of laser therapy, the injury effects and repair characteristics of skin tissue are studied through infrared laser irradiation of the skin of miniature pigs. Live pig skin was irradiated at multiple spots one time by using a grid-array method with a 1064 nm laser at different power outputs. The skin injury reaction was observed immediately after laser irradiation from low to high doses. The incidence of skin injury was calculated quantitatively. The healing and pathological changes after laser-induced skin injury were observed dynamically within 6 h and for 28 d after laser irradiation. With the increase of irradiation dose, laser-induced skin injuries ranging from mild to severe appeared in turn. The damage threshold of laser irradiation ED50 is 47.4 J cm−2 with the laser; from 3 d to 28 d after irradiation, the pathological results showed that wound healing tended to be different in all groups, but this trend weakened with the increase in laser irradiation intensity. With the increased irradiation dose, skin injury appears as different types of injury plaques, ranging from mild to severe. Skin injury is worsened and the tissue repair trend is weakened with the increase in laser irradiation dose, producing a good dose-effect and time-effect relationship.

Surface water circulation develops seasonally changing patterns of floating litter accumulation in the Mediterranean Sea. A modelling approach

Marine litter and, particularly, plastics are a growing concern at global scale. The Mediterranean Sea is among the zones in the world with the highest concentration of floating plastic debris. However, our knowledge remains limited on the spatial distribution of litter across this basin. Here, a set of different numerical model simulations were conducted to examine the dynamic conditions of the surface layer of the Mediterranean and how this drives the circulation and accumulation of floating litter. Seasonal dynamics of surface water circulation led to contrasting distribution patterns of floating litter along the year. Multiple hot spots of litter zones appeared across the basin in summer, while litter disperses and moves towards the Eastern Mediterranean and nearshore waters in winter. Taking into account such seasonal variability in the spatial patterns of litter in the Mediterranean seems to be key in the design of further sampling surveys and management strategies.

Rough contacting surfaces with elevated contact areas

We consider two elastic half-spaces contacting along multiple contact spots. In order to provide contact, these spots should be somewhat elevated; moreover, they may take the form of “columns” that connect the half-spaces. The effect of this factor on the overall compliances (normal and shear) is examined in 3-D setting, as function of the shape of the “columns”. This effect is found to be strong, and it is quite sensitive to the mentioned shape. The extent of coupling between the shape of the “columns” and interactions between them, and of the elastic contrast between the “columns” and the main material are also examined.

1372 A Rare Case of Purtscher's Retinopathy in the Setting of Acute Alcoholic Pancreatitis

INTRODUCTION: Purtscher's retinopathy (PUR) is a rare condition first described in 1910. Occlusive microvasculopathy is characterized by sudden visual loss with multiple areas of retinal whitening in the posterior pole. Associated with acute pancreatitis, connective tissue disorders, renal failure, childbirth, bone marrow transplantation. Proteases like trypsin activate the complement system cascade causing coagulation and leukoembolization of the retinal precapillary arterioles. The emboli lodge in the arterioles producing the clinical appearance of PUR with impaired visual acuity and visual field loss. We present a case of a young female with repeat acute pancreatitis who developed sudden visual changes seconday to PUR. CASE DESCRIPTION/METHODS: 28 yo F with PMH of Etoh abuse, gastritis, Mallory-Weiss tear and prior admissions for pancreatitis presented to ED with emesis and abdominal pain for one day. Exam revealed a diffusely tender abdomen. Labs included lipase (939 U/L) (aspartate aminotransferase = 351 U/L, alanine aminotransferase = 179 U/L, alkaline phosphatase = 133 U/L) and hyperbilirubinemia (1.8 mg/dL). Abdominal U/S showed peripancreatic edema correlating acute pancreatitis along with hepatomegaly and steatosis. On day 1 of admission pt complained of visual disturbances upon awakening. Acute visual changes included blurriness, flashes and floaters which completely resolved by the evening. Bedside ophthalmologic exam revealed multiple cotton wool spots bilaterally. Ophthalmology evaluation revealed macular edema and neurosensory detachment of the macula bilaterally secondary to PUR. Visual field testing showed loss of central field bilaterally with preserved peripheral vision. Acuity was 20/200 bilaterally and received intraocular steroid injections with weekly follow up. Exam at 8 weeks demonstrated improvement to visual acuity to 20/40 bilaterally. DISCUSSION: Purtscher Flecken are variable, polyglonal regions of retinal whitening with a clear zone and are pathognomonic. The treatment for the ocular complications of PuR have not been proven and prognosis depends on the areas of the retina that are affected. Isolated case reports have shown rapid improvement in vision with high dose IV steroids. Steroids help preserve the neuronal membrane and suppress granulocyte aggregation caused by complement activation. Patient's complaining of changes in vision following an episode of acute pancreatitis should undergo eye examination in order to rule out Purtscher-like retinopathy.

Performance and Emission Parameters of Homogeneous Charge Compression Ignition (HCCI) Engine: A Review

Strict emission regulations and demand for better fuel economy are driving forces for finding advanced engines that will be able to replace the conventional internal combustion engines in the near future. Homogeneous charge compression ignition (HCCI) engines use a different combustion technique; there are no spark plugs or injectors to assist the combustion. Instead, when the mixtures reach chemical activation energy, combustion auto-ignites in multiple spots. The main objective of this review paper is to study the engine performance and emission characteristics of HCCI engines operating in various conditions. Additionally, the impact of different fuels and additives on HCCI engine performance is also evaluated. The study also introduces a potential guideline to improve engine performance and emission characteristics. Compared to conventional compression ignition and spark ignition combustion methods, the HCCI combustion mode is noticeably faster and also provides better thermal efficiency. Although a wide range of fuels including alternative and renewable fuels can be used in the HCCI mode, there are some limitation/challenges, such as combustion limited operating range, phase control, high level of noise, cold start, preparation of homogeneous charge, etc. In conclusion, the HCCI combustion mode can be achieved in existing spark ignition (SI) engines with minor adjustments, and it results in lower oxides of nitrogen (NOx) and soot emissions, with practically a similar performance as that of SI combustion. Further improvements are required to permit extensive use of the HCCI mode in future.

Bat algorithm-enabled binary optimization for scattered light focusing

We introduce a novel global optimization algorithm–bat algorithm (BA) for wavefront shaping to focus light through highly scattered media. Compared with the well-known genetic algorithm, BA-based binary wavefront shaping achieves a higher enhancement with less time in noisy environments, which is validated by simulation and experiment. Using a high-speed digital micromirror device, the BA enables quick formation of single or multiple focal spots through a highly scattering layer. The BA offers a competitive algorithm for wavefront shaping in turbid media, which might benefit biomedical imaging in deep tissues.

Study of the Compression of a Condensed Deuterated Target Installed on the Wire Array Axis

The implosion of combined loads consisting of an outer wire (fiber) array and inner cylindrical target was studied experimentally at the Angara-5-1 facility (3.5 MA, 100 ns) at currents of up to 3.5 MA. The experiments were carried out with 12- and 20-mm-diameter outer arrays made of 15-μm-diameter aluminum wires, composite arrays made of aluminum wires and 25-μm-diameter kapron fibers, and arrays made of kapron fibers with a 1-μm-thick aluminum coating. The number of wires varied from 10 to 40. The targets were made of agar-agar or low-density deuterated polyethylene. The parameters of the Z-pinch plasma were determined using the Angara-5-1 diagnostic complex, which included optical streak cameras, X-ray frame cameras, X-ray detectors, X-ray pinhole cameras, neutron detectors, and a mica-crystal X-ray spectrograph. It is established that the plasma compression dynamics and the formation of local plasma structures generating neutrons depend on the load configuration: the array diameter, the number of wires (fibers), and the diameter and density of the target. The most efficient compression and the highest plasma parameters (the compression ratio and plasma temperature), as well as the highest neutron yield, were achieved in experiments with 12-mm-diameter aluminum wire arrays inside which a 1-mm-diameter deuterated target with a mass density of 0.3 g/cm3 was installed As a result of collision of the bulk of the array mass with the inner target, a compact pinch with a diameter of ≈0.5 mm forms. The pinch formation is accompanied by the generation of a soft X-ray pulse. The development of MHD instabilities in the pinch plasma results in the formation of multiple hot spots (HSs) on the pinch axis with a typical size of 200–300 μm and an electron temperature of 0.4–0.7 keV. The HS formation is accompanied by emission of neutrons with a mean energy of 2.7 ± 0.2 MeV. The maximum neutron yield achieved in these experiments was 2.6 × 1010 neutrons/shot.

Commissioning of pencil beam and Monte Carlo dose engines for non-isocentric treatments in scanned proton beam therapy

This work describes the dosimetric commissioning of the treatment planning system (TPS) RayStation v6.1 from RaySearch Laboratories (Stockholm, Sweden) for a synchrotron-based scanned proton beam delivery with isocentric and non-isocentric setups at MedAustron. Focus was on the comparison of the pencil beam (PBv4.1) and Monte Carlo (MCv4.0) calculation algorithms.Commissioning of dose calculations was done first for 1D/2D dose delivery where the performance of the beam model in reproducing dosimetric properties for the delivery of single static pencil beams and mono-energetic layers with multiple spots was evaluated. The commissioning for 3D beam delivery employed test cases with increasing complexity: from box-shaped fields in homogeneous phantoms to the introduction of oblique incidences and inhomogeneities. Dose calculations were compared to the measured data for different air gaps and using beams with and without range shifter (RaShi).Depth-dose curves and spot shape comparisons showed good agreement of the results obtained with PBv4.1 and MCv4.0 algorithms at isocentric setup for open beam configurations (without RaShi). Comparison of transverse dose profiles for lateral heterogeneities at different depths showed better performance of the MCv4.0 algorithm in comparison to the PBv4.1 algorithm. In the case of 3D delivery comparisons of measured and TPS-calculated dose with MCv4.0 algorithm in box-shaped fields in water showed an average agreement within 2%. The results for dose calculations with the PBv4.1 algorithm showed larger deviations for beams with RaShi at all evaluated air gaps (from 64.8 cm to 14.8 cm).Our results suggest that the MCv4.0 algorithm shall be used in clinics for final dose calculation when beams with RaShi are used especially in the presence of large air gaps, inclined patient surface and lateral inhomogeneities. The detailed stepwise methodology implemented for the RayStation commissioning in this work could serve as further guidance for other facilities introducing a new TPS for proton beam therapy.

N2O emission in full-scale wastewater treatment: Proposing a refined monitoring strategy

Nitrous oxide (N2O) emissions from wastewater treatment contribute significantly to greenhouse gas emissions. They have been shown to exhibit a strong seasonal and daily profile in previously conducted monitoring campaigns. However, only two year-long online monitoring campaigns have been published to date. Based on three monitoring campaigns on three full-scale wastewater treatment plants (WWTPs) with different activated sludge configurations, each of which lasted at least one year, we propose a refined monitoring strategy for long-term emission monitoring with multiple flux chambers on open tanks. Our monitoring campaigns confirm that the N2O emissions exhibited a strong seasonal profile and were substantial on all three plants (1–2.4% of the total nitrogen load). These results confirm that N2O is the most important greenhouse gas emission from wastewater treatment. The temporal variation was more distinct than the spatial variation within aeration tanks. Nevertheless, multiple monitoring spots along a single lane are crucial to assess representative emission factors in flow-through systems. Sequencing batch reactor systems were shown to exhibit comparable emissions within one reactor but significant variation between parallel reactors. The results indicate that considerable emission differences between lanes are to be expected in cases of inhomogeneous loading and discontinuous feeding. For example, N2O emission could be shown to depend on the amount of treated reject water: lanes without emitted <1% of the influent load, while parallel lanes emitted around 3%. In case of inhomogeneous loading, monitoring of multiple lanes is required. Our study enables robust planning of monitoring campaigns on WWTPs with open tanks. Extensive full-scale emission monitoring campaigns are important as a basis for reliable decisions about reducing the climate impact of wastewater treatment. More specifically, such data sets help us to define general emission factors for wastewater treatment plants and to construct and critically evaluate N2O emission models.

Adaptive multi-scale electrothermal model of REBCO coated conductors embedded in a commercial power system transient simulator

High temperature superconducting coated conductors (CCs) are wires with ideal nonlinear properties for use as resistive superconducting fault current limiters (rSFCLs) for power systems. However, choosing a conductor architecture that can survive all types of excitations occurring in a specific power system is a big challenge. Firstly, the non-uniformity of the critical current along the length of commercial CCs makes them prone to hot spots. Secondly, the current flowing in a CC-based rSFCL is determined by the specific dynamics of the power system in which it is installed. In order to correctly design the CC architecture, one must be able to compute the electrothermal bevahiour of CCs submitted to realistic power system excitations. This requires coupling a physically-representative CC model with a suitable commercial power system simulator. In this paper, an example of such coupling is presented, with the particularity that the numerical method used to simulate CCs can account for realistic lengths used in rSFCLs (hundreds of meters of CCs), while still being able to track hot spot developments on the micrometer scale, thanks to a dynamic adaptive meshing strategy. The coupling is realized within the EMTP-RV environment through a dynamic link library that contains the physical CC model. A few examples of applications are presented, in which propagation of multiple hot spots triggered by the power system are simulated in very moderate computation times. Besides helping rSFCL manufacturers to better select a proper CC architecture, the proposed model can also be used in regular power system simulations as an accurate rSFCL device model, which is expected to greatly help power system engineers to better plan their integration in the grid.

Fluorescence in Situ Hybridization (FISH) for Detecting Anaplastic Lymphoma Kinase (ALK) Rearrangement in Lung Cancer: Clinically Relevant Technical Aspects

In 2011, the Vysis Break Apart ALK fluorescence in situ hybridization (FISH) assay was approved by the United States Food and Drug Administration as a companion diagnostic for detecting ALK rearrangement in lung cancer patients who may benefit from treatment of tyrosine kinase inhibitor therapy. This assay is the current “gold standard”. According to updated ALK testing guidelines from the College of American Pathologists, the International Association for the Study of Lung Cancer and the Association for Molecular Pathology published in 2018, ALK immunohistochemistry is formally an alternative to ALK FISH, and simultaneous detection of multiple hot spots, including, at least, ALK, ROS1, RET, MET, ERBB2, BRAF and KRAS genes is also recommended while performing next generation sequencing (NGS)-based testing. Therefore, ALK status in a specimen can be tested by different methods and platforms, even in the same institution or laboratory. In this review, we discuss several clinically relevant technical aspects of ALK FISH, including pros and cons of the unique two-step (50- to 100-cell) analysis approach employed in the Vysis Break Apart ALK FISH assay, including: the preset cutoff value of ≥15% for a positive result; technical aspects and biology of discordant results obtained by different methods; and incidental findings, such as ALK copy number gain or amplification and co-existent driver mutations. These issues have practical implications for ALK testing in the clinical laboratory following the updated guidelines.

Tight focusing properties of phase modulated azimuthally polarized doughnut Gaussian vortex beam by high NA parabolic mirror

The intensity distribution in the focal region of a high NA parabolic mirror for the incident azimuthally polarized doughnut Gaussian vortex beam (DGVB) transmitted through a multi belt complex phase filter (MBCF) is studied using vector diffraction theory. By properly designing the phase of the incident beam using MBCF and by tuning the beam parameters of a DGVB, it is possible to switch the focal spot with sub wavelength dimension and long focal depth in to multiple focal spots suitable for particle acceleration, atom optical experiments, and near-field scanning optical microscopy.

Hybrid Numerical Simulation of High-Current Vacuum Arc Taking Into Account Secondary Plasma Generation

This paper is devoted to the further development of a numerical model for the simulation of high-current vacuum arcs (HCVA) with cathode attachment in the form of multiple cathode spots. The model allows one to simulate different modes of HCVA and the transition between them. It is shown that the secondary plasma, arising from the anodic sputtering and nonadherence of the incident ions, affects the constriction of the plasma and the transition between the HCVA modes.

Functional Fluorescence Microscopy Imaging: Quantitative Scanning-Free Confocal Fluorescence Microscopy for the Characterization of Fast Dynamic Processes in Live Cells.

Functional fluorescence microscopy imaging (fFMI), a time-resolved (21 μs/frame) confocal fluorescence microscopy imaging technique without scanning, is developed for quantitative characterization of fast reaction-transport processes in solution and in live cells. The method is based on massively parallel fluorescence correlation spectroscopy (FCS). Simultaneous excitation of fluorescent molecules in multiple spots in the focal plane is achieved using a diffractive optical element (DOE). Fluorescence from the DOE-generated 1024 illuminated spots is detected in a confocal arrangement by a matching matrix detector comprising 32 × 32 single-photon avalanche photodiodes (SPADs). Software for data acquisition and fast auto- and cross-correlation analysis by parallel signal processing using a graphic processing unit (GPU) allows temporal autocorrelation across all pixels in the image frame in 4 s and cross-correlation between first- and second-order neighbor pixels in 45 s. We present here this quantitative, time-resolved imaging method with single-molecule sensitivity and demonstrate its usefulness for mapping in live cell location-specific differences in the concentration and translational diffusion of molecules in different subcellular compartments. In particular, we show that molecules without a specific biological function, e.g., the enhanced green fluorescent protein (eGFP), exhibit uniform diffusion. In contrast, molecules that perform specialized biological functions and bind specifically to their molecular targets show location-specific differences in their concentration and diffusion, exemplified here for two transcription factor molecules, the glucocorticoid receptor (GR) before and after nuclear translocation and the Sex combs reduced (Scr) transcription factor in the salivary gland of Drosophila ex vivo.

High-throughput smFRET analysis of freely diffusing nucleic acid molecules and associated proteins.

Single-molecule Förster resonance energy transfer (smFRET) is a powerful technique for nanometer-scale studies of single molecules. Solution-based smFRET, in particular, can be used to study equilibrium intra- and intermolecular conformations, binding/unbinding events and conformational changes under biologically relevant conditions without ensemble averaging. However, single-spot smFRET measurements in solution are slow. Here, we detail a high-throughput smFRET approach that extends the traditional single-spot confocal geometry to a multispot one. The excitation spots are optically conjugated to two custom silicon single photon avalanche diode (SPAD) arrays. Two-color excitation is implemented using a periodic acceptor excitation (PAX), allowing distinguishing between singly- and doubly-labeled molecules. We demonstrate the ability of this setup to rapidly and accurately determine FRET efficiencies and population stoichiometries by pooling the data collected independently from the multiple spots. We also show how the high throughput of this approach can be used o increase the temporal resolution of single-molecule FRET population characterization from minutes to seconds. Combined with microfluidics, this high-throughput approach will enable simple real-time kinetic studies as well as powerful molecular screening applications.

Inducing lasing in organic materials with low optical gain by three-dimensional plasmonic nanocavity arrays.

Lasing in organic media with very low gain has been pursued for a long time in optoelectronics. Here, we experimentally demonstrate that plasmonic lasing in the visible regime at room temperature can be achieved by hybridizing active media of very low optical gain such as ionic liquid and polymethylmethacrylate with three-dimensional (3D) plasmonic metamaterials. The 3D nanostructure consists of a double-layer N-shaped silver wire-hole array with strongly coupled multiple hot spots densely packed in each unit cell. These hot spots overlap perfectly with the gain media, allowing efficient gain-plasmon coupling in subwavelength volumes. The periodic arrangement of hot spots, as the metal and dielectric are distributed in an alternate manner along both transverse and vertical directions, results in ultrastrong suppression of scattering losses. In addition, the lasing characteristics, including threshold, intensity and polarization can be controlled by the lattice constant and geometry of metamaterials. Such a plasmonic nanolaser proves to be of low threshold and low gain requirement, providing an essential step towards easy-processing organic based optoelectronics.

Optical coherence tomography angiography in Purtscher-like retinopathy associated with dermatomyositis: a case report

PurposeTo describe a multimodal imaging diagnosis of retinopathy in dermatomyositis.Case presentationA 21-year-old white woman with a history of fatigue and a cutaneous rash complained of visual impairment in her left eye. A funduscopic examination showed multiple confluent cotton-wool spots in both eyes. Swept source-optical coherence tomography presented macular edema in both eyes; optical coherence tomography angiography revealed superficial and deep capillary occlusion in all areas affected by cotton-wool spots; and fluorescein angiography showed vascular walls enhancement, veins dilatation, and capillary leakage. After large doses of intravenously administered glucocorticoid therapy, followed by a cyclophosphamide regimen, best corrected visual acuity returned to 20/20 in both eyes.ConclusionsThis case report presents optical coherence tomography angiography clinical findings in a rare case of dermatomyositis-associated retinopathy, remarking the importance of a multi-imaging approach for a correct diagnosis and treatment of eye injuries, in order to avoid serious complications and permanent sequelae.

CORRELATION BETWEEN VISUAL FUNCTIONS AND OPTICAL COHERENCE TOMOGRAPHY, FUNDUS AUTO FLUORESCENCE AND FUNDUS FLUORESCEIN ANGIOGRAPHY FINDINGS IN TREATMENT-NAIVE DIABETIC MACULAR EDEMA

Background: Diabetic macular edema (DME) is a sightthreatening consequence of diabetic retinopathy. So, identifyingreliable methods for DME prognosis is actually very helpful. Multimodal retinal imaging tools provide us with these predictive prognostic biomarkers Aim of the Work: To correlate between visual functions (visual acuity and color vision) with macular features of OCT, FAF and FFA in patients with untreated (treatment naive) DME as a guide for visualprognosis of these patients. Patients and Methods: Fifty eyes of35 diabetic patients with untreated clinically significant macular edema (CSME)underwent best corrected visual acuity (BCVA) determination (logMAR), fluoresce in angiography(FFA;FAZ size, macular leakage pattern, areas of capillary dropout)optical coherence tomography (OCT; central point foveal thickness [CPFT], volume, outer and inner retinal layers integrity[ONL,INL],hyper-reflective foci[HRF], subfoveal choroidal thickness[SFCT]); fundus auto fluorescence (Hyper FAF; absent or increased (FAF, single or multiple spots). Linear correlation and three-way analysis of covariance were used for statistics. Results: In OCT, we found that CPFT & ORL integrity is significantly well correlated to visual function (BCVA, color vision).However, CSFT was only correlated to visual acuity but not color vision. Regarding FFA parameters, especially (FAZ size, areas of capillary drop out), we found that these parameters are correlated significantly to visual acuity but not color vision. On the other hand,we found that the presence of hyper FAF spots was not related significantly to visual acuity but related to a significant level to color vision. However, a number of spots were not correlated to visual acuity or color vision. There was significant correlation between retinal thickness in OCT and type of leakage in FFA. Also, large cystoid spaces and FAF spots in the fovea were significantly correlated together. Conclusions: Integration between different retinal imaging tools in DME helps to find alternative and less invasive way in diagnosis.FAF is new, simple non-invasive imaging mode to assess RPE function with evolving application in DME.