Nomarski Differential Interference Contrast Research Articles

Morphological and Molecular Characterization of Two New Species of Ceratomyxa Thélohan, 1892 (Cnidaria: Myxosporea) from the Marine Ornamental Fish Zanclus cornutus (Linnaeus, 1758) off Lakshadweep Islands, Arabian Sea.

The present study provides the complete morphological and molecular description of two new species of myxosporeans, Ceratomyxa zancli n. sp. and Ceratomyxa cornuti n. sp. infecting the gallbladder of Zanclus cornutus from the Lakshadweep Islands, Arabian Sea. Zanclus cornutus were screened for the presence of myxosporeans, and the recovered myxospores were morphologically characterized using Nomarski Differential Interference Contrast (DIC) optics. The sequences of SSU rDNA were employed for molecular and phylogenetic studies. Both the parasites exhibited a prevalence of 21% each. C. zancli n. sp. is characterized by broadly cresentic myxospores with convex anterior and slightly concave to straight posterior margins and rounded ends. Spore valves two, unequal, measured 9.6 ± 0.7μm × 25.2 ± 1.3μm. Polar capsules two, unequal, spherical, measured 4 ± 0.6μm × 3.5 ± 0.6μm. Polar filament exceptionally long and arranged irregularly. Myxospores of C. cornuti n. sp. are elongated with convex anterior and slightly concave to straight posterior margins. Spore valves two, unequal, measured 7.00 ± 0.4μm × 26.56 ± 1.8μm. Polar capsules spherical, unequal, measured 3.52 ± 0.2 × 3.36 ± 0.35. Molecular analysis of C. zancli n. sp. (ON818297) and C. cornuti n. sp. (ON818298) resulted in 1469 and 1491bp long SSU rDNA sequences, respectively. Molecularly C. zancli n. sp. is close to C. diplodae and C. barnesi with 91.39% similarity, while C. cornuti n. sp. appears closer to C. robertsthomsoni with 97.46% similarity. In phylogenetic analyses, C. zancli n. sp. branched separately within the Ceratomyxa clade while C. cornuti n. sp. clustered with C. robertsthomsoni and C. thalassomae. Based on the differences in morphological, morphometric, molecular, and phylogenetic characteristics, as well as differences in the host and geographic location, the above two species of myxosporeans are considered novel. The study forms the first report of a species of Ceratomyxa from Z. cornutus.

A spatial carrier dynamic quantitative differential phase imaging method

Differential interference contrast (DIC) microscopy is an important method for quantitative phase imaging (QPI) due to its high compatibility regarding to partial coherent light illumination and excellent optical sectioning ability. However, limited by the on-axis interferometric configuration of Nomarski DIC microscopic imaging system, it is difficult to achieve single-shot phase retrieval. Here, we propose a simple and efficient method for dynamic quantitative differential phase imaging (QDPI) by introducing a spatial carrier device into DIC microscope. A Wollaston prism (WP) is placed on the imaging plane of DIC microscope and then projected by a 4f imaging system, so two orthogonally polarized imaging beams with a certain shearing amount will interfere on the conjugate plane of the 4f imaging system and form a spatial carrier DIC image, thus the QDPI can be conveniently realized. Importantly, the system not only possesses high temporal phase stability provided by the common-path geometries and low spatial phase noise due to partially coherent light illumination, but also the advantages of simple optical implementation, no additional phase distortion, high light energy utilization efficiency, and high signal-to-noise ratio. The experimental result demonstrates that using the proposed method, the phase measurement sensitivity reaches 0.003 rad, the corresponding applicability is verified by a polystyrene microsphere crown and biological cells.

Morphological and Molecular Characterization of Myxobolus planilizae n. sp. (Cnidaria; Myxosporea; Myxobolidae) Infecting the Largescale Mullet Planiliza macrolepis (Smith, 1846) Collected From Cochin Backwaters, India.

Myxobolus planilizae n. sp. is described from the intestinal muscles of the largescale mullet Planiliza macrolepis from Cochin backwaters, Kerala, India. Host fishes inhabiting Cochin backwaters were collected using Chinese nets/gill nets. The morphometry and morphological studies were carried out using Nomarski differential interference contrast (DIC) optics, followed by molecular and phylogenetic analyses of the small subunit ribosomal DNA gene (SSU rDNA). Plasmodia small, pale white, and infect the muscles of the intestine; measured 0.13-0.22 (0.17) × 0.09-0.14 (0.13) mm. Mature myxospores pyriform in valvular view, and biconvex in sutural and apical views with a short anterior extension, and measured 7.45-8.75 (8.40) × 6.04-6.86 (6.25) µm. Shell valves with sutural ornamentations. Polar capsules two, equal, pyriform, measured 3.96-4.54 (4.45) × 2.22-2.94 (2.52) µm. Polar filament arranged in five coils, measured 24.41-34.44 (28.52) µm when extruded. In morphological and morphometric analysis, the present species exhibit remarkable variations from other species of the genus Myxobolus. In molecular analysis, the present species revealed the highest identity of 91.85% and divergence of 9.95% with related species, underlining its molecular uniqueness. In phylogenetic analysis, species of Myxobolus infecting mullets appeared as a separate clade and the present species was positioned distinctly with a high bootstrap value. Based on morphology, morphometry, and molecular and phylogenetic analyses, along with tissue/host specificities and geographic location, the present parasite is treated as new and is reported here as M. planilizae n. sp.

Sphaeromyxa cornuti n. sp., a New Species of Myxosporean Infecting the Gallbladder of the Moorish Idol, Zanclus cornutus (Linnaeus, 1758) from Lakshadweep Waters.

The present study describes a new species of myxosporean, Sphaeromyxa cornuti n. sp. infecting the gallbladder of the Moorish idol, Zanclus cornutus (Linnaeus 1758) collected from Lakshadweep waters of the Arabian Sea. Fish were collected using traps and cages. The morphology of mature spores recovered from the gallbladder of Z. cornutus was studied under Nomarski Differential Interference Contrast (DIC) optics. The molecular and phylogenetic analyses were based on SSU rDNA. Sphaeromyxa cornuti n. sp. is characterized by arcuate myxospores with tapering extremities and round ends in valvular, and slightly sigmoid in sutural views (19.2-24.7 µm × 4.1-5.7µm). The two polar capsules are unequally elongate-ovoid in shape and positioned at opposite ends of the spore (6.2-9.7µm × 1.7-2.6µm). Each encloses an irregularly folded, ribbon-like polar tubule, which is oriented parallel to polar capsule axis. In molecular and phylogenetic analyses, the present myxosporean revealed significant differences with related forms and clustered together with S. hellandi within the 'incurvata' group of the Sphaeromyxa clade with high nodal support. Morphological, morphometric, molecular and phylogenetic differences between our material and previously described species of Sphaeromyxa, along with host and geographic variations indicate that the present myxosporean is unique and the name Sphaeromyxa cornuti n. sp. is proposed. This forms the first report of a myxosporean parasite-infecting Z. cornutus.

Assessment of Neuronal Cell Death in Caenorhabditis elegans.

The nematode Caenorhabditis elegans is a powerful experimental platform for cell biology studies. The molecular mechanisms that mediate cell death and neurodegeneration have been characterized extensively in the nematode. In addition, the availability of a wide arsenal of genetic and molecular tools and methodologies renders C. elegans an organism of choice for modeling human neurodegenerative diseases. Indeed, neuronal necrosis can readily be observed and examined in vivo, in the worm. In this chapter, we describe the two main approaches that are routinely used for monitoring and quantifying neuronal cell death in C. elegans. The first is based on direct visualization of dying cells via Nomarski differential interference contrast (DiC) microscopy, and the second on the assessment of neuronal survival by fluorescence microscopy.

Statistical image processing quantifies the changes in cytoplasmic texture associated with aging in Caenorhabditis elegans oocytes

BackgroundOocyte quality decreases with aging, thereby increasing errors in fertilization, chromosome segregation, and embryonic cleavage. Oocyte appearance also changes with aging, suggesting a functional relationship between oocyte quality and appearance. However, no methods are available to objectively quantify age-associated changes in oocyte appearance.ResultsWe show that statistical image processing of Nomarski differential interference contrast microscopy images can be used to quantify age-associated changes in oocyte appearance in the nematode Caenorhabditis elegans. Max–min value (mean difference between the maximum and minimum intensities within each moving window) quantitatively characterized the difference in oocyte cytoplasmic texture between 1- and 3-day-old adults (Day 1 and Day 3 oocytes, respectively). With an appropriate parameter set, the gray level co-occurrence matrix (GLCM)-based texture feature Correlation (COR) more sensitively characterized this difference than the Max–min Value. Manipulating the smoothness of and/or adding irregular structures to the cytoplasmic texture of Day 1 oocyte images reproduced the difference in Max–min Value but not in COR between Day 1 and Day 3 oocytes. Increasing the size of granules in synthetic images recapitulated the age-associated changes in COR. Manual measurements validated that the cytoplasmic granules in oocytes become larger with aging.ConclusionsThe Max–min value and COR objectively quantify age-related changes in C. elegans oocyte in Nomarski DIC microscopy images. Our methods provide new opportunities for understanding the mechanism underlying oocyte aging.

Live Animal Imaging and Cell Sorting Methods for Investigating Neurodegeneration in a C. elegans Excitotoxic Necrosis Model.

Excitotoxic necrosis is a leading form of neurodegeneration. This process of regulated necrosis is triggered by the synaptic accumulation of the neurotransmitter glutamate, and the excessive stimulation of its postsynaptic receptors. However, information on the subsequent molecular events that culminate in the distinct neuronal swelling morphology of this type of neurodegeneration is lacking. Other aspects, such as changes in specific subcellular compartments, or the basis for the differential cellular vulnerability of distinct neuronal subtypes, remain under-explored. Furthermore, a range of factors that come into play in studies that use in vitro or ex vivo preparations might modify and distort the natural progression of this form of neurodegeneration. It is therefore important to study excitotoxic necrosis in live animals by monitoring the effects of interventions that regulate the extent of neuronal necrosis in the genetically amenable and transparentmodel system of the nematode Caenorhabditis elegans. This protocol describes methods of studying excitotoxic necrosis in C. elegans neurons, combining optical, genetic, and molecular analysis. To induce excitotoxic conditions in C. elegans, aknockout of a glutamate transporter gene (glt-3) is combined with a neuronal sensitizing genetic background (nuls5 [Pglr-1::GαS(Q227L)]) to produce glutamate receptor hyperstimulation and neurodegeneration. Nomarski differential interference contrast (DIC), fluorescent, and confocal microscopy in live animals are methods used to quantify neurodegeneration, follow subcellular localization of fluorescently labeled proteins, and quantify mitochondrial morphology in the degenerating neurons. Neuronal Fluorescence Activated Cell Sorting (FACS) is used to distinctly sort at-risk neurons for cell-type specific transcriptomic analysis of neurodegeneration. A combination of live imaging and FACS methods as well as the benefits of the C. elegans model organism allow researchers to leverage this system to obtain reproducible data with a large sample size. Insights from these assays could translate to novel targets for therapeutic intervention in neurodegenerative diseases.

Biomineralization Capacities of Chlorodendrophyceae: Correlation Between Chloroplast Morphology and the Distribution of Micropearls in the Cell

Several species of the genus Tetraselmis (Chlorodendrophyceae, Chlorophyta) were recently discovered to possess unsuspected biomineralization capacities: they produce multiple intracellular inclusions of amorphous calcium carbonate (ACC), called micropearls. Early light-microscopists had spotted rows of refractive granules in some species, although without identifying their mineral nature. Scanning electron microscope (SEM) observations showed that the distribution of the micropearls in the cell forms a pattern, which appears to be characteristic for a given species. The present study shows that this pattern correlates with the shape of the chloroplast, which differs between Tetraselmis species, because micropearls align themselves along the incisions between chloroplast lobes. This was observed both by SEM and in live cells by light microscopy (LM) using Nomarski differential interference contrast. Additionally, molecular phylogenetic analyses, of rbcL and ITS2 gene sequences from diverse strains of Chlorodendrophyceae, corroborated the morphological observations by identifying two groups among nominal Tetraselmis spp. that differ in chloroplast morphology, micropearl arrangement, and ITS2 RNA secondary structure.

Genetic Dissection of Apomixis in Dandelions Identifies a Dominant Parthenogenesis Locus and Highlights the Complexity of Autonomous Endosperm Formation.

Apomixis in the common dandelion (Taraxacum officinale) consists of three developmental components: diplospory (apomeiosis), parthenogenesis, and autonomous endosperm development. The genetic basis of diplospory, which is inherited as a single dominant factor, has been previously elucidated. To uncover the genetic basis of the remaining components, a cross between a diploid sexual seed parent and a triploid apomictic pollen donor was made. The resulting 95 triploid progeny plants were genotyped with co-dominant simple-sequence repeat (SSR) markers and phenotyped for apomixis as a whole and for the individual apomixis components using Nomarski Differential Interference Contrast (DIC) microscopy of cleared ovules and seed flow cytometry. From this, a new SSR marker allele was discovered that was closely linked to parthenogenesis and unlinked to diplospory. The segregation of apomixis as a whole does not differ significantly from a three-locus model, with diplospory and parthenogenesis segregating as unlinked dominant loci. Autonomous endosperm is regularly present without parthenogenesis, suggesting that the parthenogenesis locus does not also control endosperm formation. However, the high recovery of autonomous endosperm is inconsistent with this phenotype segregating as the third dominant locus. These results highlight the genetic complexity underlying apomixis in the dandelion and underline the challenge of introducing autonomous apomixis into sexual crops.

Detecting Gold-Labeled Cells

Colloidal gold particles bind tightly but not covalently to proteins at pH values that are around the protein's pI. Colloidal gold particles conjugated with a wide range of anti-immunoglobulin antibodies, Protein A, or streptavidin are available commercially. Gold labels were developed originally for electron microscopic studies, but they also work well at the level of the light microscope. They give higher resolution than enzyme-based methods and avoid the problems of substrate preparation and endogenous enzyme activity. Until recently, the gold labels lacked sensitivity at the level of light microscopy, but the recent development of the photochemical silver method of amplification, described here, has overcome this problem. Unamplified gold labels can be detected under the light microscope using bright-field illumination in which the label ranges from pale pink to deep red, depending on the strength of the reaction. Nomarski differential interference contrast microscopy makes the label appear dark red to black. With the silver enhancement method, the gold particles become coated in metallic silver and yield a black-brown label, best visualized by bright-field optics. Gold labeling methods are compatible with many histochemical stains. Gold labeling reactions are very readily controlled, because the appearance of staining can be monitored directly and continuously under the microscope.

On the optimum off-cut angle for the growth on InP(111)B substrates by molecular beam epitaxy

InGaAs and InAlAs epilayers were grown on InP(111)B substrates by molecular beam epitaxy. Rather than focusing on a specific off-cut angle, the growths were done on rounded wafer edges, which expose a broad spectrum of vicinal surfaces with varying off-cut angle and off-cut azimuth. The epilayers were grown at several different growth conditions by varying the growth temperature, growth rate, and arsenic (As) overpressure. The epitaxial layers were characterized at the center and the edge of the wafers using Nomarski differential interference contrast microscopy and atomic force microscopy. It was shown that a minimum misorientation angle of ∼0.4° should be used in order to avoid pyramidal hillocks. At higher misorientations, 1.7°–3°, step bunching can lead to surface roughening.

Growth and optical characteristics of Tm-doped AlGaN layer grown by organometallic vapor phase epitaxy

We report on the growth and optical properties of Tm-doped AlGaN layers by organometallic vapor phase epitaxy (OMVPE). The morphological and optical properties of Tm-doped GaN (GaN:Tm) and Tm-doped AlGaN (AlGaN:Tm) were investigated by Nomarski differential interference contrast microscopy and photoluminescence (PL) characterization. Nomarski images reveal an increase of surface roughness upon doping Tm into both GaN and AlGaN layers. The PL characterization of GaN:Tm shows emission in the near-infrared range originating from intra-4f shell transitions of Tm3+ ions. In contrast, AlGaN:Tm also exhibits blue light emission from Tm3+ ions. In that case, the wider band gap of the AlGaN host allows energy transfer to higher states of the Tm3+ ions. With time-resolved PL measurements, we could distinguish three types of luminescent sites of Tm3+ in the AlGaN:Tm layer, having different decay times. Our results confirm that Tm ions can be doped into GaN and AlGaN by OMVPE, and show potential for the fabrication of novel high-color-purity blue light emitting diodes.

Quantitative estimate of interstitial clays in sandstones using Nomarski differential interference contrast (DIC) microscopy and image analysis

The Nomarski differential interference contrast (DIC) microscopy in the reflected–light visualizes a virtual surface relief of rock components through varying resistance to grinding and polishing of different mineral phases. In the case of sandstones, illustrated here with an example of the Cergowa sandstones (Lower Oligocene) from the Flysch Carpathians, the used analytical technique depicts a homogeneity with no or very weak relief in the surface morphology of all components besides clay particles, where a virtual relief is observed. Thereby, the Nomarski DIC imaging proved to be very useful in a distinction between an interstitial matrix and other binders of sedimentary rocks. Such separation with standard petrographic examinations is often far from clear which causes usually an overstatement of the matrix content and an incorrect rock classification.Such monotonous picture of sandstones as from the Nomarski DIC microscopy seems to be easy to apply in an image analysis. In the case of the Cergowa sandstones, an automatic extraction of clay matrix in an image analysis was disturbed by numerous replacements of some minerals (especially feldspars) by clay minerals that were detected as a matrix with an illusory relief. The applied manual approach in the ImageJ analysis programme pointed out: two of six analysed images were overestimated by means of the polarising microscopy. In both cases, the matrix content was estimated >15%, whilst in the Nomarski DIC images showed contents of 10.5% and 10.2%, what classifies them as arenites, not wackes.The presence of clay matrix in sandstones has a great influence on their petrophysical properties, including the most important porosity and permeability, a sufficient amount of which permits to accumulate crude oil or natural gas under adequate trapping conditions. Therefore, their correct extraction and measurement is so substantial.

Automated Photoreceptor Cell Identification on Nonconfocal Adaptive Optics Images Using Multiscale Circular Voting.

PurposeAdaptive optics scanning light ophthalmoscopy (AOSLO) has enabled quantification of the photoreceptor mosaic in the living human eye using metrics such as cell density and average spacing. These rely on the identification of individual cells. Here, we demonstrate a novel approach for computer-aided identification of cone photoreceptors on nonconfocal split detection AOSLO images.MethodsAlgorithms for identification of cone photoreceptors were developed, based on multiscale circular voting (MSCV) in combination with a priori knowledge that split detection images resemble Nomarski differential interference contrast images, in which dark and bright regions are present on the two sides of each cell. The proposed algorithm locates dark and bright region pairs, iteratively refining the identification across multiple scales. Identification accuracy was assessed in data from 10 subjects by comparing automated identifications with manual labeling, followed by computation of density and spacing metrics for comparison to histology and published data.ResultsThere was good agreement between manual and automated cone identifications with overall recall, precision, and F1 score of 92.9%, 90.8%, and 91.8%, respectively. On average, computed density and spacing values using automated identification were within 10.7% and 11.2% of the expected histology values across eccentricities ranging from 0.5 to 6.2 mm. There was no statistically significant difference between MSCV-based and histology-based density measurements (P = 0.96, Kolmogorov-Smirnov 2-sample test).ConclusionsMSCV can accurately detect cone photoreceptors on split detection images across a range of eccentricities, enabling quick, objective estimation of photoreceptor mosaic metrics, which will be important for future clinical trials utilizing adaptive optics.

Threading dislocations in MBE grown AlInSb metamorphic buffers: Revealed and counted

The authors compare four methods to investigate the threading dislocations (TDs) observed in metamorphic buffers used in the growth of InSb quantum well on GaAs (001) substrates. Three types of buffers with varying number of Al0.24In0.76Sb interlayers (N = 0, 1, and 3) were studied. Cross-sectional scanning transmission electron microscopy (STEM) revealed an effective dislocation filtering by the interlayers. Individual TDs were identified with atomic-force microscopy (AFM) as distinct morphological features of dislocation outcrops on the surface. Threading dislocation density (TDD) is reduced by 1 order of magnitude with three interlayers, consistent with the STEM observation. TDD measured with a scanning electron microscope in electron channeling contrast imaging (ECCI) mode agrees closely with the AFM analysis, except for the N = 0 buffer where the ECCI gives TDD lower by more than a factor of two. The etch pit density of N = 3 buffer, measured with a Nomarski differential interference contrast microscope after defect selective etching (DSE), is almost 1 order of magnitude lower than the TDD measured by AFM and ECCI. Due to the large pit size, the used etching recipe only works well for samples with TDD lower than 107 cm−2. AFM, ECCI, and DSE are excellent alternatives to transmission electron microscopy in the process of metamorphic buffer optimization. The AFM technique offers the additional advantage of high vertical resolution morphology mapping. Such capability is of great importance for the optimization of metamorphic buffers from the perspective of surface smoothness improvement.

Cytotoxic activity of genistein-8-C-glucoside form Lupinus luteus L. and genistein against human SK-OV-3 ovarian carcinoma cell line

Genistein belongs to isoflavones, which are a subclass of flavonoids, a large group of polyphenolic compounds widely distributed in plants. Numerous in vitro studies suggest that isoflavones, particularly genistein, have both chemopreventive and chemotherapeutic potential in multiple tumor types. However, the molecular and cellular mechanisms of genistein effects on human ovarian cancer cells are still little known. In the present study, we investigated anticancer activity of genistein and its natural glucoside, genistein-8-C-glucoside isolated from flowers of Lupinus luteus L. We examined the effects of the two isoflavones alone or in combination on cultured human SK-OV-3 ovarian carcinoma cells. The cells were exposed to genistein and genistein-8-C-glucoside at various concentrations (1–90 µM) for 24 and 48 h. The cytotoxic and apoptotic properties of compounds were studied by the colorimetric 3-[4,5-2-yl]-2-5-diphenyltetrazolium bromide assay and the acridine orange/ethidium bromide staining technique. The morphological features of SK-OV-3 cells were examined by Nomarski differential interference contrast combined with a confocal laser scanning microscope. The level of ROS was evaluated with fluorescence probes: dichlorofluorescein-diacetate by flow cytometry. Changes in mitochondrial membrane potential were determined using 5,5,6,6-tetrachloro-1,1,3,3-tetraethylbenzimidazolcarbocyanine iodide. Genistein-treatment and genistein-8-C-glucoside-treatment resulted in the inhibition of cell proliferation, induction of apoptotic cell death and loss of mitochondrial membrane potential. The present data provide the first evidence in vitro that genistein-8-C-glucoside and combination genistein-genistein-8-C-glucoside could be a potential chemotherapeutic candidate for ovarian cancer therapy.

Faster and more accurate improved rescue ICSI by observing changing size and position of chromosome and spindle using polarization microscope and differential contrast microscope

Unfertilization after conventional IVF is confirmed by the existence of Metaphase-II (M-II) chromosome and first polar body. Spindle examination in unfertilized eggs using the polarization microscope is useful to assist rescue ICSI. However it has limitations since this apparatus observes only the existence of spindle not the stage of nuclear maturation (M-II, Anaphase-II or Telophase-II). Nomarski differential interference contrast microscopy clarifies each stage of second meiotic cell division. We performed this retrospective study to investigate the usefulness of this new improved technique. Retrospective cohort study for development of rescue ICSI. 425 Oocytes from 38 patients who agreed to participate in this study were observed 4 hours after insemination from January 2015 to December 2015. Unfertilized oocytes were identified by the normal width of chromosomes at M-II stage without extrusion of second polar body or white colored spindle with full length adjacent to the cytoplasmic membrane. Fertilized oocytes showed half width of chromosome in a line and shortening spindle 2-3 hours after the start of the fertilization (Anaphase-II). As fertilization was proceeding, M-II chromosomes became aggregated and divided into second polar body with spindle crossing the membrane 3-4 hours later. About 4 hours after insemination, second polar body extruded with remaining round M-II chromosomes and spindle was observed close to the perivitelline space (Telophase-II). 5-6 hours later small female pronucleus appeared just below the second polar body without the spindle. 1. The 425 freshly ovulated M-II oocytes were examined. The proportion of unfertilized oocytes that remained at M-II stage was 20.4% (87/425), fertilized oocytes after completion of second meiosis was 79.5% (338/425). 2. The fertilization, cleavage, blastocyst stage rates, pregnancy and miscarriage rates in fertilized oocytes (A) and unfertilized oocytes followed by new rescue ICSI (B) are listed in Table. No 1PN or 3PN oocytes could be observed both in group A and B. Not all of M-II oocytes could be identified as having completed second meiosis after insemination. Some chromosomes were scattered or degenerated. Whether oocyte was fertilized or unfertilized was more easily and quickly identified with the combination of Nomarski differential interference contrast microscopy and polarization microscope. The early and accurate identification of fertilization is beneficial for rescue unfertilized oocytes following conventional IVF.Tabled 1Clinical outcome following new rescue ICSIFertilization rates (%)Cleavage rates (%)Blastocyst rates (%)Pregnancy rates (%)Miscarriage rates (%)A(n=328)78.564.545.333.420.5B(n=87)52.462.333.225.525.6 Open table in a new tab

EVALUATION OF ESCHERICHIA COLI INFECTION CONTROL AS THE MOST PREVALENT ISOLATE AFFECTING SPERM PARAMETERS

Genital tract infection and inflammationhavebeenassociatedto8-35%ofmaleinfertilitycases.E.colicausesagglutination of human spermatozoa and thus, leading to infertility. This study aim to evaluate if the negative influenceofEscherichiacoli on the motility of human spermatozoa is a consequence of E. coli adhesion or some soluble factor from E. coli are involved. Highly motile preparation of spermatozoa from normozoospermic patients were obtained by ‘swim up’ procedure the. Study was carried out in three parts. Motility parameters were analysed by light microscopy and Nomarski differential interference contrast microscopy directly, and after 30 min; 2, 4, 6 hs and overnight after inoculation. In The second series of experiments, bacterial replication was inhibited by addition of fiveantibioticsamoxicillin,ciprofloxacin,erythromycin,gentamycinandpenicillin G. The effect of E. coli culture filtratesonspermmotilitywasinvestigated.FinallyInathirdseries,E.coligrowthwassuppressed by heating at high temperature (100 oC) for 30 min. E. coli decreased the sperm motility and viability by agglutination immediately after inoculation and effect increases as the time of incubation Period increases.Amazingly , both culture media in which E. coli growth was inhibited by either (antibiotic and heating), was not able to cause any change in motility and viability. Further more, completion of incubation at Period up to 6 hs the percentage of motile spermatozoa left is 11% that is very low as compared to control. This shows that E. coli may be carrying some adhesion sites through which it binds to human spermatozoa and causes agglutination. And hence infartility

Probing patterned defects on graphene using differential interference contrast observation

We present here a simple optical-imaging technique for observing patterned defects on graphene. Photolithography was performed to limit areas on graphene that would be exposed to an oxygen plasma when it was introduced to generate defects on the graphene. The patterned defects were systematically characterized using conventional Nomarski differential interference contrast (DIC) observations with a nematic liquid crystal in conjunction with micro-Raman spectroscopy, which showed that the defects on graphene increased with increasing durations of oxygen-plasma treatment. Distinct differences in reflected-light Nomarski DIC were observed in the regions with defects. The combination of the DIC imaging and micro-Raman spectroscopy provides a fast, direct, and scalable method to evaluate the defects on graphene.

Effect of water regime and vegetation on initial granite weathering in a glacier forefield: Evidences from CL, SEM, and Nomarski DIC microscopy

Glacier forefields are characterised by high spatial variability in water availability, solar radiation, and vegetation, as well as weathering processes. The aim of this study is to improve the understanding of initial weathering of granite material with respect to the water regime (availability and residence time of the water) and the vegetation cover. Samples of granite powder were buried in four selected sites at the Damma glacier forefield for one year. A combined application of cathodoluminescence (CL) microscopy and spectroscopy, scanning electron microscopy (SEM), and Nomarski differential interference contrast (Nomarski DIC) microscopy was used to investigate the initial stage of weathering. The examination of the initial weathering stage revealed that the exposed mineral grains were strongly characterised by intra-variations. A clear change in particle shape and surface morphology could not be observed within the relatively short exposure period of one year. However, the grains from the lake sediment exhibited a clearly rounded shape, caused by mechanical abrasion during transport processes. The combination of several microscopic methods revealed (i) a strong influence of vegetation in the case of plagioclase-oligoclase alteration, (ii) a mutual effect of water and vegetation in the case of biotite delamination, and (iii) alterations of potassium feldspar independent of local environments. Investigations with cathodoluminescence microscopy showed the suppression of blue luminescence and developed brown luminescence and confirmed a new insight in potassium feldspar weathering.