Capillary Layer Research Articles

Biofabrication of Tobacco mosaic virus-nanoscaffolded supercapacitors via temporal capillary microfluidics

This paper reports the implementation of temporal capillary microfluidic patterns and biological nanoscaffolds in autonomous microfabrication of nanostructured symmetric electrochemical supercapacitors. A photoresist layer was first patterned on the substrate, forming a capillary microfluidics layer with two separated interdigitated microchannels. Tobacco mosaic virus (TMV) macromolecules suspended in solution are autonomously delivered into the microfluidics, and form a dense bio-nanoscaffolds layer within an hour. This TMV layer is utilized in the electroless plating and thermal oxidation for creating nanostructured NiO supercapacitor. The galvanostatic charge/discharge cycle showed a 3.6-fold increase in areal capacitance for the nanostructured electrode compared to planar structures. The rapid creation of nanostructure-textured microdevices with only simple photolithography and bionanostructure self-assembly can completely eliminate the needs for sophisticated synthesis or deposition processes. This method will contribute to rapid prototyping of wide range of nano-/micro-devices with enhanced performance.

The Unique Paired Retinal Vessels of the Gray Short-Tailed Opossum (Monodelphis domestica) and Their Relationship to Astrocytes and Microglial Cells.

In marsupials that possess a retinal vasculature, the arterial and venous segments, down to the smallest calibre capillaries, have been shown to occur in pairs. This pattern is seen in the marsupial central nervous system (CNS) but not in other tissues in this group or in any tissues in eutherian mammals. The present study aimed to determine if the gray short-tailed opossum (Monodelphis domestica), a south American marsupial, possesses double retinal vessels. Secondly, we investigated the relationship between vessels and astrocytes and microglia, which are known to play pivotal roles in the blood retinal barrier and immune surveillance respectively. Eyes from M. domestica between 2 months and 33 months of age were examined by bright field and fluorescein angiography, resin histology, and wholemount immunostaining. Retinal vessels in this marsupial always occur in closely related pairs with the arteriolar limb usually on the vitread aspect. Branches penetrate the retina to form layers of paired capillaries as far as the outer nuclear layer. Dense networks of GFAP+ astrocytes enveloped the vitread aspect of vessels. No particularly strong association with blood vessels and ramified Iba1+ and Ib4+ microglia was noted. M. domestica possessed the unusual paired vasculature and capillary loops arrangement previously described in the marsupial CNS. These observations in a small laboratory-friendly marsupial open up new frontiers to investigate the factors that regulate paired blood vessel development and the functional significance of this arrangement when compared to the anastomotic pattern observed in the retina of eutherian mammals. Anat Rec, 300:1391-1400, 2017. © 2017 Wiley Periodicals, Inc.

Evaluation of choroidal tumors with optical coherence tomography: enhanced depth imaging and OCT-angiography features.

AimTo describe the vascular features of choroidal tumors using enhanced depth imaging (EDI), optical coherence tomography (OCT), and OCT-angiography.MethodsIn this prospective study, we evaluated 116 Caucasian patients with choroidal tumors (60 eyes with choroidal nevi, 40 with choroidal melanoma, 6 with choroidal hemangioma, 2 with optic disc melanocytoma, 6 with choroidal osteoma, and 2 with retinal metastases). Patients underwent a complete ophthalmic examination including bulbar echography, EDI-OCT, OCT-angiography, and multicolor imaging. Sixteen patients also underwent fluorescein and indocyanine angiography.ResultsThe left eye was more involved than the right eye. The mean tumor thickness was 1.23±0.17 mm in the 60 eyes with choroidal nevi; 2.75±0.83 mm in the 40 eyes with choroidal melanoma; 3.28±0.78 mm in the 6 eyes with retinal angioma; 2.02±0.001 mm in the 2 eyes with optic disc melanocytoma; 2.40±0.31 mm in the 6 eyes with choroidal osteoma; and last, 3.49±0.001 mm in the 2 eyes with retinal metastases. OCT-angiography showed: (i) a lack of blood flow in the outer retinal layer (ORL) and a normal choroid capillary layer in choroidal nevi and optic disc melanocytomas; (ii) a lack of blood flow in the ORL of choroidal metastases; and (iii) a dense irregular vascular network in the ORL and choroid capillary layers of choroidal melanomas, choroidal hemangiomas, and choroidal osteomas.ConclusionsOCT-angiography is a noninvasive reliable method with which to evaluate the vascularization of small choroidal tumors and may improve the diagnosis of these tumors.

Hydrogeological Behaviour of Covers with Capillary Barrier Effects Made of Mining Materials

A laboratory study and numerical predictions were conducted to evaluate the effectiveness of a cover with capillary barrier effects (CCBE) made of mining materials in limiting the generation of acid mine drainage. The present study included the installation of three experimental laboratory columns as physical models of CCBEs. Each column was instrumented to monitor the hydrogeological behaviour of the different layers of the cover. In the moisture-retaining layer, which is made of desulphurized tailings, the degree of saturation (Sr) is usually maintained above 85%, while Sr in the two waste rock layers placed above and below the moisture-retaining layer (MRL) is typically between 5 and 15%. Suctions were usually lower than the air entry value for the desuphurized tailings layers, while suctions largely exceeded the water entry value of the mine waste rock in the two capillary break layers (CBLs). The oxygen flux was calculated using numerical modeling at the bottom of the MRL. Results confirm that the oxygen flux is low (between 0.34 and 3 g/m2/year). This study also confirms the potential of mine waste rocks to act as a substitute for natural granular soils in the CBL of a CCBE.

A preliminary study on macular retinal and choroidal thickness and blood flow change after posterior scleral reinforcement by optical coherence tomography angiography

Objective: To investigate macular retinal and choroidal thickness and blood flow change using optical coherence tomography angiography after posterior scleral reinforcement (PSR) surgery. Methods: Prospective study. Twenty eyes of 10 patients with high myopia were enrolled in this open-label, single-treatment group and prospective study. Radial lines and Angio retina (3 mm×3 mm) module were performed for 20 eyes using Angio-vue optical coherence tomography (Avanti, Optovue) without pupil dilation, and best corrected visual acuity, spherical equivalent and axial length were compared before and 60 days after surgery. Retinal and choroidal thickness was measured in the fovea, 1 mm superior, 1 mm inferior, 1 mm nasal and 1 mm temporal to the fovea. Flow area, flow density and flow index were recorded using self-provided software in the superficial retina layer, deep retina layer, outer retina layer and choroid capillary layer, respectively. Statistical analysis was performed using SPSS 16.0. Data that followed normal distribution were compared with paired two-sample t-test, while others were compared with Wilcoxon signed rank test. Results: Of the patients participating in this preliminary study, the mean age was (35.5±4.2) years, and 50% were female. No significant difference was found between before and 60 days after PSR surgery in best corrected visual acuity (t=0.99, P=0.33), spherical equivalent (t=-1.89, P=0.07) and axial length (t=0.2, P=0.08). The retinal thickness in the fovea was thinner (Z=-2.58, P=0.01), while there was no significant difference in the 1 mm superior (t=0.44, P=0.67) , 1 mm inferior (t=0.05, P=0.96) , 1 mm nasal (Z=0.87, P=0.64) and 1 mm temporal (Z=-0.78, P=0.99) to the fovea. No significant difference was found in choroidal thickness (t=-0.12, P=0.87; t=-0.25, P=0.81. t=0.53, P=0.61; t=-0.91, P=0.38. t=1.2, P=0.25) before and after surgery. The postoperative flow density in the superficial and deep retinal layers (48.18±4.56% and 31.47±5.11%) was significantly increased (t=2.66, P=0.02; t=3.16, P=0.01) compared with pre-operation (33.82±4.33% and 14.29±3.89%). The postoperative flow index in the superficial and deep retina layers (0.044±0.005 and 0.025±0.005) was significantly increased (t=2.59, P=0.02. t=2.95, P=0.01) compared with pre-operation (0.028±0.004 and 0.010±0.003). The other flow measurements showed no significant difference. Conclusion: Retinal thickness decreased, and flow density and index increased in the superficial and deep retinal layers after PSR surgery. This suggested blood flow improvement in the macular region after PSR surgery in high myopic eyes. (Chin J Ophthalmol, 2017, 53:39-45).

Hydrogeological behaviour of an inclined store-and-release cover experimental cell made with phosphate mine wastes

A field study was conducted at the Kettara mine site located in arid climatic conditions in Morocco. The goal was to assess the performance of an inclined store-and-release (SR) cover made with phosphate mine wastes to reduce water infiltration and control acid mine drainage (AMD). The SR cover was constructed using phosphate mine wastes (0.8 m) placed over a capillary break layer (CBL) made of coarse-grained materials. The SR cover had a slope inclination of 14.5°. The cover performance was monitored for a period of 1 year under natural and artificial conditions representing important rainfall events for the climatic conditions at the Kettara mine site. Performance was monitored using volumetric lysimeters, suction sensors, and volumetric water content sensors installed at four stations and at different depths. Under natural climatic conditions, the inclined SR cover limited water percolation by diverting and releasing water to the atmosphere through evaporation. However, the cover was unable to store and divert all the water at a precipitation rate >100 mm in 48 h, and percolation was observed in the lysimeters. Nevertheless, the results confirmed the suitability of phosphate mine wastes as cover material for a 31.5 m inclined (≈ 14.5°) SR cover placed over the Kettara mine wastes in natural climatic conditions and for precipitation events <100 mm in 48 h.

Low-threshold 1.9 µm Raman generation in microstructured hydrogen-filled hollow-core revolver fibre with nested capillaries

Efficient Raman laser based on the revolver hollow-core fibre (HCF) with a cladding formed by one layer of double nested capillaries was realized for the first time. Using hydrogen gas as a nonlinear medium we demonstrated single-pass single-stage 1064 nm–1907 nm Raman conversion with quantum efficiency as high as 40%. Improved mode confinement in the hollow core and low optical losses of the fibre enabled us to achieve Raman threshold as low as 270 W of peak power, which is 4–7 times improvement compared to previously reported results on 1.9 µm Raman generation in other types of HCFs. Further progress in revolver fibre technology could be a promising way to develop low-threshold, efficient, compact gas fibre lasers for various applications in the mid-infrared spectral range.

Retinal Hemodynamics Seen on Optical Coherence Tomography Angiography Before and After Treatment of Retinal Vein Occlusion.

This study evaluates the retinal hemodynamics using optical coherence tomography angiography (OCTA) before and after anti-vascular endothelial growth factor (VEGF) therapy in patients with macular edema associated with retinal vein occlusion (RVO). Twelve patients (23 eyes; mean age, 64 years) were included (eight eyes with branch RVO, four with central RVO, and 11 unaffected fellow eyes. The best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were measured before and 6 months after treatment. The foveal avascular zone (FAZ), nonperfused areas (NPAs), and flow area were evaluated with OCTA before and after treatment. The BCVA and CRT improved significantly after treatment. In eyes with RVO, the baseline FAZ in the retinal deep capillary layer was larger than in fellow eyes and enlarged in the retinal superficial and deep capillary layers after therapy; NPAs decreased after therapy, especially in the retinal deep capillary layer; and the baseline flow area was smaller than in fellow eyes and improved after therapy, especially in the retinal deep capillary layer. Optical coherence tomography angiography can evaluate the retinal hemodynamics in patients with RVOs. Anti-VEGF therapy reduced the NPA size and improved retinal blood flow, especially in the retinal deep layer. The current results suggested that anti-VEGF therapy might improve retinal deep ischemia in patients with RVO in the retinal deep layer, which is abundant in capillaries.

Optical Coherence Tomography Angiography in Diabetes.

Diabetic retinopathy is a progressive microvascular disease that leads to increased vessel permeability, retinal ischemia, and retinal neovascularization. Optical coherence tomography angiography (OCTA) is a novel angiography technique that has the capability to advance our understanding of diabetic eye disease by providing high-resolution images of retinal and choroidal microvasculature blood flow and structure. Using OCTA, the vascular changes of diabetic retinopathy including microaneurysms, retinal non-perfusion, intraretinal microvascular abnormalities, and neovascularization can be clearly visualized. OCTA offers several advantages over fluorescein angiography (FA) in that it is faster, safer, and non-invasive, allows better visualization of retinal vessels in both the superficial and deep capillary layers, and can provide quantitative measurements of areas of non-perfusion of the macula and nerve. OCTA capillary perfusion density maps and average perfusion density values provide an easy way to grade progressive vascular change. Despite these advantages, imaging with OCTA can only provide a limited view of the peripheral retina and is unable to demonstrate leakage, staining, or pooling. OCTA requires patients to maintain good fixation to obtain high-resolution images which can be a challenge for those with severe macular disease. In patients who cannot safely undergo FA, OCTA may serve as an alternative form of angiography that can be safely and more frequently performed for the management of diabetic retinopathy.

Optical coherence tomography angiography in age-related macular degeneration: persistence of vascular network in quiescent choroidal neovascularization.

Optical coherence tomography angiography in age-related macular degeneration: persistence of vascular network in quiescent choroidal neovascularization.

OCT angiography in Retinal Angiomatous Proliferation

SummaryRetinal Angiomatous Proliferations (RAP) have been described initially on ophthalmoscopy as a chorioretinal anastomosis in a late stage of AMD and of MACTEL. Fluorescein angiography evidences a dilated perimacular retinal capillary with late profuse leakage of dye. ICG angiography is instrumental to detect Retinal Angiomatous Proliferation at an early stage of development, especially in AMD. A localized effraction of the RPE on OCT evidences the communication between retinal and choroidal circulation with massive fluid infiltration of the retina. The basic idea of OCT angiography was to separate moving objects from static tissue. This new technic is suitable for 3D segmentation and reconstruction of the retinal capillary layers. There are a number of questions that OCTA may help to solve. What is the participation of the deep retinal capillary plexus to the clinically visible RAP? Is the portion perpendicular to the retinal plane a capillary of the intermediate layer? Does RAP involving only the deep retinal plexus exist? Is the PED part of the process? OCTA may be of great value to the understanding of the pathophysiology of the early stage of the disorder and may offer noninvasive monitoring of the disease progression and activity, aiding for each treatment assessment.

Choriocapillaris Flow Features Follow a Power Law Distribution: Implications for Characterization and Mechanisms of Disease Progression

To investigate flow characteristics of the choriocapillaris using optical coherence tomography angiography. Retrospective observational case series. Visualization of flow in individual choriocapillary vessels is below the current resolution limit of optical coherence tomography angiography instruments, but areas of absent flow signal, called flow voids, are resolvable. The central macula was imaged with the Optovue RTVue XR Avanti using a 10-μm slab thickness in 104 eyes of 80 patients who ranged in age from 24 to 99 years of age. Automatic local thresholding of the resultant raw data with the Phansalkar method was analyzed with generalized estimating equations. The distribution of flow voids vs size of the voids was highly skewed. The data showed a linear log-log plot and goodness-of-fit methods showed the data followed a power law distribution over the relevant range. A slope intercept relationship was also evaluated for the log transform and significant predictors for variables included age, hypertension, pseudodrusen, and the presence of late age-related macular degeneration (AMD) in the fellow eye. The pattern of flow voids forms a scale invariant pattern in the choriocapillaris starting at a size much smaller than a choroidal lobule. Age and hypertension affect the choriocapillaris, a flat layer of capillaries that may serve as an observable surrogate for the neural or systemic microvasculature. Significant alterations detectable in the flow pattern in eyes with pseudodrusen and in eyes with late AMD in the fellow eye offer diagnostic possibilities and impact theories of disease pathogenesis.

Negative curvature hollow core fibers for Raman lasing in the mid IR spectral range

In this paper we consider a problem of using negative curvature hollow-core fibers for creation of Raman lasers in the mid IR spectral range. New designs of this type of fibers with cladding formed by one layer of double nested capillaries are discussed and their optical properties are investigated numerically and experimentally. It will be shown that it is possible to reduce the Raman generation threshold by decreasing an effective mode area in such fibers using nested capillaries in the cladding.

Characteristics of fundus image in macular telangiectasia type 2

Objective To observe the fundus image characteristics of macular telangiectasia type 2 (MacTel type 2) patients. Methods A total of 8 patients (16 eyes) diagnosed of MacTel type 2 were included in this study. There were 4 males and 4 females, age ranged from 44 to 69 years old with a median age of (59.88±7.85) years. All patients received examination of best-corrected visual acuity (BCVA), slit lamp microscope, indirect ophthalmoscopy, fundus color photography, fundus autofluorescence (AF), fundus fluorescein angiography (FFA), spectral domain optical coherence tomography (OCT) and macular pigment optical density (MPOD). Four eyes of 2 patients received OCT angiography examination at the same time. Classification was made according to the Gass and Blodi′s criteria. The follow-up time was from 1 to 19 months with the average time of (11.00±8.91) months. The clinical characteristics were observed and analyzed. Results The BCVA was 0.07 - 0.8. There were 1 eye in stage 1, 1 eye in stage 2, 6 eyes in stage 3, 8 eyes in stage 4. The disease showed a bilateral appearance with a low progression. Fundus features included loss of retinal transparency (14 eyes, 87.5%), blunted retinal venule (15 eyes, 93.75%), pseudo-lamellar hole (5 eyes, 31.25%), pigment proliferation (9 eyes, 56.25%). FFA findings were telangiectatic capillaries predominantly temporal to the foveola in the early phase and a diffuse hyperfluorescence in the late phase. Spectral domain OCT features included depletion of the retinal inner, outer structures, cavity (7 eyes, 43.75%), and atrophy of the neurosensory retina (9 eyes, 56.25%). On AF, reduced foveal masking due to loss of macular pigment can be observed. The loss of macular pigment could also be seen on MPOD. OCTA showed the increased intervascular spaces, broken regular network of foveal avascular zone (FAZ), right-angled vessel dipping, dilatations, traction of superficial and deep capillary layers in both the superficial and deep layers, especially in the deep layer. Only one eye of one patient proceeded from stage 4 to stage 5. Conclusions Characteristic features of MacTel type 2 included cavities and outer retina atrophy on OCT; loss of MP on MPOD; broken regular network of FAZ, morphological and structural abnormalities of superficial and deep layers of perifoveal capillary network on OCTA. Key words: Retinal Diseases/diagnosis; Macula lutea/injuries; Disease attributes

Abstract 307: Apoa-1 Binding Protein Regulates Retinal Angiogenesis via Control of Notch Signaling

ApoA-1 binding protein (AIBP), a mediator of cholesterol efflux from endothelia cells to HDL, plays a vital role in zebrafish angiogenesis. Although it is evolutionary conserved from Drosophila to human, its role of angiogenesis in higher vertebrate has not been studied. Thus, we propose that the role of AIBP in angiogenesis is also conserved from zebrafish to mice to humans. Mouse models display tremendous power in the study of human cardiovascular disease as the murine and human vasculatures are highly similar. We therefore generated Aibp -/- mice, which are viable and fertile. We then compared retinal vasculature development in Aibp -/- mice and wild-type control mice by whole mount immunostaining. Our data show that AIBP deficiency in mice results in significantly enhanced angiogenesis, including an increase in the radial extension of vascular plexus, the development of a denser upper capillary layer, and more tip cells as well as filopodia in the retinas. Notch signaling pathway plays an essential role for proper angiogenesis. However, the role of cholesterol metabolism in the Notch pathway is poorly understood. We found the expressions of the Notch downstream targets Hes1, Hey1 and Hey2 were upregulated in Aibp -/- retinas compared to controls. Furthermore, the protein level of Notch intracellular domain (NICD) was decreased in Aibp -/- retinas. These results suggest that the activity of Notch signaling is decreased in retinas from Aibp -/- mice. Mechanistically, we found AIBP positively regulates Notch signaling by affect on γ-secretase activity. Moreover, we performed Matrigel plug assay. Comparing that of wild-type, Matrigel plugs from Aibp -/- mice has more VE-cadherin staining and higher VE-cadherin mRNA expression level; and shows lower Hey1 expression as well as decreased NICD protein levels. It indicates that Matrigel plugs from Aibp -/- mice expresses more blood vessels and show lower Notch signaling activity. Our study demonstrated that AIBP inhibits angiogenesis by activating the Notch pathway and are the first to connect AIBP, a cholesterol metabolism regulator, to Notch signaling.

Determining the imaging plane of a retinal capillary layer in adaptive optical imaging**Project supported by the National Natural Science Foundation of China (Grant Nos. 11174274, 11174279, 61205021, 11204299, 61475152, and 61405194).

Even in the early stage, endocrine metabolism disease may lead to micro aneurysms in retinal capillaries whose diameters are less than 10 μm. However, the fundus cameras used in clinic diagnosis can only obtain images of vessels larger than 20 μm in diameter. The human retina is a thin and multiple layer tissue, and the layer of capillaries less than 10 μm in diameter only exists in the inner nuclear layer. The layer thickness of capillaries less than 10 μm in diameter is about 40 μm and the distance range to rod&cone cell surface is tens of micrometers, which varies from person to person. Therefore, determining reasonable capillary layer (CL) position in different human eyes is very difficult. In this paper, we propose a method to determine the position of retinal CL based on the rod&cone cell layer. The public positions of CL are recognized with 15 subjects from 40 to 59 years old, and the imaging planes of CL are calculated by the effective focal length of the human eye. High resolution retinal capillary imaging results obtained from 17 subjects with a liquid crystal adaptive optics system (LCAOS) validate our method. All of the subjects’ CLs have public positions from 127 μm to 147 μm from the rod&cone cell layer, which is influenced by the depth of focus.

Optical Coherence Tomography Angiography in Central Retinal Vein Occlusion: Correlation Between the Foveal Avascular Zone and Visual Acuity.

To investigate the relationship between best-corrected visual acuity (BCVA) and the foveal avascular zone (FAZ) in patients with central retinal vein occlusion (CRVO) evaluated with optical coherence angiography (OCT-A). The study was a prospective consecutive case series including 24 patients with CRVO. All patients received either aflibercept or ranibizumab intravitreal injections prior to analysis. Best-corrected visual acuity and FAZ were evaluated in eyes without macular edema. The FAZ areas were evaluated with OCT-A in both the superficial and deep capillary plexus layers by using 3 × 3-mm images of the macula. Disruption of the ellipsoid zone (EZ) was also analyzed. The mean superficial FAZ area measured 0.76 mm2 (95% confidence interval [CI] 0.50-1.13). The mean deep FAZ area measured 1.12 mm2 (95% CI 0.77-1.47). In a multivariable analysis a negative correlation was found between the BCVA and the superficial FAZ area (r = -0.54, P = 0.03). The correlation between the BCVA and deep FAZ area did not meet statistical significance (r = -0.43, P = 0.09). In a multivariable analysis, disruption of the ellipsoid zone was significantly correlated to a larger superficial FAZ area (r = 0.68, P = <0.001) and poor visual acuity (r = 0.75, P < 0.001). Optical coherence tomography-A is a novel technique that allows segmented evaluation of the FAZ in patients with CRVO providing additional prognostic information. The FAZ areas were enlarged both in the superficial and the deep capillary networks. A significant correlation was found between BCVA and the FAZ area in CRVO patients without macular edema (ClinicalTrials.gov, number NCT02274259).

Wide-field optical coherence tomography angiography using extended field imaging technique to evaluate the nonperfusion area in retinal vein occlusion

PurposeOptical coherence tomography angiography (OCTA) is a newly developed technology which allows us to reconstruct the three-dimensional chorioretinal vasculature without dye injection. OCTA is a noninvasive, rapid, and reproducible method to assess retinal ischemia. However, one of its limitations is the size of scanning area. A novel yet simple technique to expand the scan length on optical coherence tomography has been reported as an extended field imaging (EFI) technique. It involves imaging the posterior pole through trial frames fitted with a +20 diopter lens. We applied this technique to OCTA to evaluate retinal vein occlusion.Materials and methodsTen eyes of nine patients with retinal vein occlusion were studied. The average age was 69.0 years (range: 49–93 years). We obtained OCTA images by using RTVue XR Avanti OCT with AngioVue®. The images of OCTA with scan size of 8×8 mm were obtained with and without EFI, and then they were compared.ResultsOCTA with EFI technique was performed successfully in all eyes. The nonperfusion area was well defined in superficial capillary plexus layer. The images with EFI were able to capture the larger area of the fundus by an average of 188.5% than those without EFI. The posterior pole inside the vascular arcade was well covered with this technique. The area of the fundus imaged by OCTA with EFI technique was even larger than that of fluorescein angiography using Heidelberg Retina Angiograph 2, which captured a 30° field.ConclusionOur results suggested that OCTA with EFI technique is very useful to evaluate the retinal ischemia in retinal vein occlusion.

Simulation and fabrication of micro-structured optical fibers with extruded tubes

Chalcogenide glass is fragile and devitrifiable to be fabricated into micro-structured optical fibers (MOFs). In this article, MOFs which have jacket tubes with inner hexagon are designed and fabricated. The optical properties, such as effective refractive index, electric field intensity, effective mode area, nonlinear coefficient and chromatic dispersion of the fundamental mode are simulated by using full-vectorial finite element method (FVFEM). The effects of structural parameters variation on these optical characteristics of the proposed MOFs are investigated. Furthermore, the As2S3 glass capillaries and jacket tubes are made by extrusion. The MOF with three layers of capillaries is fabricated by the “Stack & Draw” technique. The lowest attenuation of 6.34dB/m of the MOF is measured at the wavelength of 4.61μm using the cut-back method.

Pathology, immunohistochemistry, and ultrastructural findings associated with neurological sarcocystosis in cattle

Paraffin-embedded blocks of brain of a nine months old bull calf that died of neurological signs in 1982 in Germany were restudied. Numerous schizonts and merozoites were found associated with extensive but focal necrosis and severe meningoencephalitis. Developing stages of schizonts as well as free merozoites were identified. The schizonts were primarily in perivascular areas. Ultrastructurally, schizonts were seen both in capillaries and in extravascular space. Merozoites were often concentrated in adventitial layers of capillaries. Schizonts divided by endopolygeny, the nucleus became multi-lobed, and at the terminal stage nuclear lobes were incorporated into budding merozoites. Individual merozoites were seen in neurons, astrocytes, oligodendrocytes, leukocytes, and vascular endothelial cells. Occasionally merozoites were present in the nucleus of mononuclear cells. Individual merozoites were ovoid, 3–5×2–3μm in size, and contained a prominent nucleus, numerous micronemes, a conoid, but no rhoptries. Schizonts and merozoites did not react to polyclonal rabbit Neospora caninum, Toxoplasma gondii, and Sarcocystis neurona antibodies but did react to Sarcocystis cruzi antibodies. Because of morphological characteristics and the type of lesions, the parasite was likely due to an unidentified Sarcocystis species, different from S. cruzi.