Pure Mg wires with a maximum cumulative area reduction of 98% were obtained by successful cold drawing. Mechanical properties, microstructures and texture evolution of the as-drawn wires were investigated by tensile t...Pure Mg wires with a maximum cumulative area reduction of 98% were obtained by successful cold drawing. Mechanical properties, microstructures and texture evolution of the as-drawn wires were investigated by tensile tests, transmission electron microscopy (TEM) and electron backscattering diffraction (EBSD). Depended on the mechanical properties and microstructure evolution, continuous dynamic recrystallization (DRX) had taken place during the cold drawing process. DRX during cold deformation has not been reported in other literatures before.展开更多
Diagnosis of Trypanosoma brucei rhodesiense human African trypanosomiasis requires demonstration of parasites in body fluids by microscopy. The microscopy methods that are routinely used are difficult to deploy in res...Diagnosis of Trypanosoma brucei rhodesiense human African trypanosomiasis requires demonstration of parasites in body fluids by microscopy. The microscopy methods that are routinely used are difficult to deploy in resource-limited settings due to practical challenges, including lengthy and tedious procedures, and the need for specific equipment to centrifuge samples in glass capillary tubes. We report here on a study that was conducted in a rural region of eastern Uganda to evaluate new methods that take advantage of a field-deployable LED fluorescence microscope. Examination of acridine orange-stained blood smears by LED fluorescence microscopy resulted in a diagnostic accuracy that was similar to that of routine methods, while the time needed to identify parasites was shortened significantly. These findings make these new microscopy methods attractive alternatives to procedures that are currently used for diagnosis of T. b. rhodesiense human African trypanosomiasis.展开更多
Background: Confirmatory diagnosis of Trypanosoma brucei gambiense human African trypanosomiasis (HAT) is based on demonstration of parasites by microscopy. However, the sensitivity of routine microscopy methods is ve...Background: Confirmatory diagnosis of Trypanosoma brucei gambiense human African trypanosomiasis (HAT) is based on demonstration of parasites by microscopy. However, the sensitivity of routine microscopy methods is very low, and many cases are missed and left untreated. A clinical study was conducted in the Democratic Republic of the Congo to evaluate the accuracy of improved microscopy methods in diagnosis of HAT. These included examination by fluorescence microscopy (FM) of acridine orange (AO) stained smears of whole blood and smears made following a new procedure for concentrating trypanosomes by selective lysis of red blood cells (RBC). Methodology/Principal Findings: Venous blood was collected from 213 HAT cases, 101 HAT suspects and 95 controls and used to determine the accuracy of four microscopy methods: bright field microscopy of Giemsa-stained thick blood smears, FM of AO-stained thick blood smears, FM of AO-stained thick blood smears prepared after RBC lysis and concentration, and FM of AO-stained thin blood smears prepared after RBC lysis and concentration. The sensitivity of FM using thick blood smears stained with AO was 3 times higher than bright field microscopy using Giemsa-stained thick blood smears [19.7% (95% CI: 14.9% - 25.6%) versus 6.1% (95% CI: 3.6% - 10.2%)]. When the RBC lysis and concentration procedure was included, sensitivity of the test was further enhanced to 23.0% (95% CI: 17.9% - 29.1%) with thick blood smears and 34.3% (95% CI: 28.2% - 40.9%) with thin blood smears. Specificity of all four microscopy methods was 100% (95% CI: 96.1% - 100.0%). However, the miniature anion exchange chromatography technique (mAECT) and capillary tube centrifugation (CTC) method remained more sensitive. Conclusions: These new methods have practical advantages, including shorter staining time, ease of demonstration of parasites, and the possibility of archiving slides. They could, therefore, be alternative methods to improve case detection where concentration procedures such as mAECT or CTC are not performed.展开更多
Melanosomes, isolated by centrifugal separation from culture broth of B16 melanoma cells derived from mouse, were observed by scanning electron microscopy (SEM), and by transmission electron microscopy (TEM). Some int...Melanosomes, isolated by centrifugal separation from culture broth of B16 melanoma cells derived from mouse, were observed by scanning electron microscopy (SEM), and by transmission electron microscopy (TEM). Some interesting structural features were found inside and outside of the melanosomes. By SEM observation, the melanosomes were ellipsoid shape, their surface was not smooth and was covered with rough substructure, 10 to 20 nm particles. By TEM, uneven structure and micro particles were observed in the melanosomes. Furthermore, three-dimensional analysis was tried by using the ultra-high voltage electron microscopy(UHVEM). Micrographs of the melanosomes were taken at various tilted angles by UHVEM, after preparing 500 nm thickness specimens stained with lead citrate. From the micrographs collected, the three-dimensional structures were reconstructed by using i-mode software. Melanin stained by lead and non stained parts was clearly observed in the reconstructed structure. Non stained parts were round, regular size, and distributed widely in the melanosomes.展开更多
In the present study, histopathology of three varieties of sesame TS 3, TS 5 and SG 27 infected with Alternaria alternata was carried out to understand the mechanism of fungal infection and penetration in sesame plant...In the present study, histopathology of three varieties of sesame TS 3, TS 5 and SG 27 infected with Alternaria alternata was carried out to understand the mechanism of fungal infection and penetration in sesame plant as well as to determine the histological manifestation in sesame cells by light microscopy. Fungus was identified in infected tissues as a dark bluish black with toluidine blue O staining. Light microscopic examination of sesame stem showed that the fungus was present in epidermis, hypodermis and cortical parenchyma tissue as the symptoms became visible by naked eye ten days after inoculation (DAI). As the disease progress, the fungus moved from cortical parenchyma to vascular bundle, xylem and phloem. Later on, it completely overlapped the vascular bundle and entered in pith. When necrotic lesion appeared, fungus was present abundantly in epidermis, hypodermis, cortical parenchyma, vascular bundles and in pith. Due to its excessive growth and complete overlapping of cells, disorganization or destruction of cells of sesame took place. It was concluded that the Alternaria alternata was not a tissue limited pathogen instead of this it spread in to all tissues of stem from epidermis to pith.展开更多
The Scanning Electron Microscopy (SEM) and Optical Microscopy (OM) with integrated digital camera are techniques that are used in the present investigation, for the morphological characterization of a new composite ma...The Scanning Electron Microscopy (SEM) and Optical Microscopy (OM) with integrated digital camera are techniques that are used in the present investigation, for the morphological characterization of a new composite material called “organic polymer concrete” in which microparticles added fibers and polyethylene terephthalate (PET) recycling mechanically (RM). Polymer concrete (PC) is a new composite material (MC) in the application considered as an alternative material of construction in which reinforcement particles are recycled polymers which have approximately the same dimensions in all directions. Therefore, the particles can be rods, spheres, chips and many other shapes whose appearance reasons are about 10 microns. These MC, the size, shape and distribution and the ratio and the modulus of the particles affect the properties of the material.展开更多
Solid polymer electrolytes (SPEs) of polyacrylamide-co-acrylic acid (PAA) as the polymer host and zinc acetate (ZnA) as an ionic dopant were prepared using a single solvent by the solution casting technique. The amorp...Solid polymer electrolytes (SPEs) of polyacrylamide-co-acrylic acid (PAA) as the polymer host and zinc acetate (ZnA) as an ionic dopant were prepared using a single solvent by the solution casting technique. The amorphous and crystalline structures of film were investigated by X-ray diffraction (XRD). The surface morphology of samples was examined by scanning electron microscopy (SEM). The composition and complex formation of films were characterized by Fourier transform infrared (FTIR) spectroscopy. The conductivity of the PAA-ZnA films was determined by electrochemical impedance spectroscopy. According to the XRD and FTIR analyses, all electrolyte films were in amorphous state and the existence of interaction between Zn2+ cations and the PAA structure confirms that the film was successfully prepared. The SEM observations reveal that the electrolyte films appeared to be rough and flat with irregularly shaped surfaces. The highest ionic conductivity (σ) of 1.82 × 10-5 Scm-1 was achieved at room temperature (303 K) for the sample containing 10 wt % ZnA.展开更多
Urea-formaldehyde (UF) resin is widely used as an adhesive for the manufacture of a range of wood and fiber based products. Although the microstructure of this resin has been examined at high resolution by field-emiss...Urea-formaldehyde (UF) resin is widely used as an adhesive for the manufacture of a range of wood and fiber based products. Although the microstructure of this resin has been examined at high resolution by field-emission scanning electron microscopy and atomic force microscopy, transmission electron microscopy (TEM) has thus far not been used, perhaps because of difficulties in ultrathin sectioning this resin in cured (polymerized) state. In the technical note presented here, a novel sample preparation method is described which enabled us to examine the microstructural morphology of UF resin by transmission electron microscopy in ultrathin sections, revealing the presence of spherical particles within the resin. Our initial attempt to ultrathin section the resin directly was not successful as it was too brittle to trim blocks for sectioning. Then, we developed a sample preparation technique that involved impregnation ofPinus radiatawood tissues with the UF resin, and then embedding of resin impregnated wood tissues with Spurr’s low viscosity embedding medium, which has been widely employed in plant and wood ultrastructure work. The TEM images illustrated and the information on the microstructural morphology of the UF resin presented are based on this novel sample preparation approach.展开更多
An epitaxial SixGey layer on a silicon substrate was quantitatively evaluated using rocking curve (RC) and reciprocal space map (RSM) obtained by powder X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (E...An epitaxial SixGey layer on a silicon substrate was quantitatively evaluated using rocking curve (RC) and reciprocal space map (RSM) obtained by powder X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) in conjunction with transmission electron microscopy (TEM), and EDS in conjunction with scanning electron microscopy (SEM). To evaluate the relative deviation of the quantitative analysis results obtained by the RC, RSM, SEM/EDS, and TEM/EDS methods, a standard sample comprising a Si0.7602Ge0.2398 layer on a Si substrate was used. The correction factor (K-factor) for each technique was determined using multiple measurements. The average and standard deviation of the atomic fraction of Ge in the Si0.7602Ge0.2398 standard sample, as obtained by the RC, RSM, TEM/EDS, and SEM/EDS methods, were 0.2463 ± 0.0016, 0.2460 ± 0.0015, 0.2350 ± 0.0156, and 0.2433 ± 0.0059, respectively. The correction factors for the RC, RSM, TEM/EDS, and SEM/EDS methods were 0.9740, 0.9740, 1.0206, and 0.9856, respectively. The SixGey layer on a silicon substrate was quantitatively evaluated using the RC, RSM, and EDS/TEM methods. The atomic fraction of Ge in the epitaxial SixGey layer, as evaluated by the RC and RSM methods, was 0.1833 ± 0.0007, 0.1792 ± 0.0001, and 0.1631 ± 0.0105, respectively. After evaluating the results of the atomic fraction of Ge in the epitaxial layer, the error was very small, i.e., less than 3%. Thus, the RC, RSM, TEM/EDS, and SEM/EDS methods are suitable for evaluating the composition of Ge in epitaxial layers. However, the thickness of the epitaxial layer, whether the layer is strained or relaxed, and whether the area detected in the TEM and SEM analyses is consistent must be considered.展开更多
Transmission electron microscopy (TEM) is a very powerful technique for materials characteriza-tion, providing information relating to morphology, composition, and crystal structure. Selected area diffraction patterns...Transmission electron microscopy (TEM) is a very powerful technique for materials characteriza-tion, providing information relating to morphology, composition, and crystal structure. Selected area diffraction patterns (SADPs) are crystallographic data that can be obtained using a TEM in-strument. Conventional identification through SADP/TEM is tricky and tedious, thereby increasing the difficulty of phase identification. To establish a procedure for phase identification of known and unknown phases, in this study we examined two samples: one, a known phase, was Si with alignment;the other, unknown, was the TixOy phase at the 96.4Au-3Ni-0.6Ti interlayer/ yttria-stabilized zirconia (YSZ) interface of a steel/96.4Au-3Ni-0.6Ti interlayer/YSZ joint. The procedures for phase identification of the known and unknown phases are described herein using a series of SADPs and energy dispersive spectrometry within TEM that would be useful for general researchers.展开更多
Acid rain (AR) has been reported to induce stress in plants affecting its productivity, growth, flowering and physiology. The molecular changes induced in plants due to the effect of acid rain or acid induced orientat...Acid rain (AR) has been reported to induce stress in plants affecting its productivity, growth, flowering and physiology. The molecular changes induced in plants due to the effect of acid rain or acid induced orientation or chloroplast streaming remains largely unknown. Therefore, in the current study we report for the first time the static and permanent changes in the cell of the medicinal plant Bacopa monnieri L. due to sulphur-simulated acid rain (S-SiAR). AR induced effects witnessed by the reduction of the size of starch granules and chloroplast, amount of the granules per unit area, dissolving cell walls, breaking the normal fiber, salt-induced strain in the various components of the cell. Effect of starch granule and chloroplast due to S-SiAR was analyzed using light, confocal and scanning electron microscopic techniques. The elements viz. potassium and magnesium present in the chloroplasts reveal acidic pH due to effect of S-SiAR observed by the ionization of Mg and K (to Mg2+ and K+), in which K+ induced by the effects of S-SiAR revealed a net negative Nernst potential of about -87.55 mV. Calcium is mainly present on the cell walls and responsible for binding of starch granules become ionized to Ca2+ on interacting with AR indicated by the altered Nernst potential of +137.04 mV. A net potential difference may cause the above streaming of chloroplast towards the large starch granules. From this study, we report AR-induced physiological changes in medicinal plant Bacopa monnieri L. for the first time.展开更多
The procedure to measure liposome in aqueous solution has been examined using atomic force microscope (AFM). We concluded a chemical modified silicon wafer (substrate for AFM observation of liposome) with 3-aminopropy...The procedure to measure liposome in aqueous solution has been examined using atomic force microscope (AFM). We concluded a chemical modified silicon wafer (substrate for AFM observation of liposome) with 3-aminopropyltrieth-oxysilane (APTES) which enabled us to scan anionic liposome softly in water because they were keeping structures as vesicles and stably adsorbed on the substrate by electrostatic force. From captured AFM topographic images, we counted the amount of liposome and analyzed the distribution of mean diameters, which were corrected by an approximated curve of the tip shape. We discussed the method of effective evaluation as practical analysis and its problems for robust analysis.展开更多
In this contribution, an experimental setup to investigate the defect luminescence between 0.72 - 0.85 eV of single defects in Silicon by optical microscopy is introduced. For this purpose, an optical microscope is eq...In this contribution, an experimental setup to investigate the defect luminescence between 0.72 - 0.85 eV of single defects in Silicon by optical microscopy is introduced. For this purpose, an optical microscope is equipped with an InGaAs CCD detector and a longpass filter with a cut-off wavelength at 1450 nm in order to filter out the band-to-band luminescence at around 1.1 eV. Grain boundaries showing homogeneous distributed defect luminescence can be localized at a μm-scale.展开更多
Bulk Czochralski silicon crystals were decorated with Cu and characterized by transmission electron microscopy (TEM) with energy-dispersive spectroscopy (EDS), atomic force microscopy (AFM), optical microscopy (OM), s...Bulk Czochralski silicon crystals were decorated with Cu and characterized by transmission electron microscopy (TEM) with energy-dispersive spectroscopy (EDS), atomic force microscopy (AFM), optical microscopy (OM), scanning electron microscopy (SEM), and photoluminescence spectroscopy (PL). The vacancy-type core, oxidation-induced stacking faults (OISF) ring, nearly defect-free ring, and self-interstitial-type rich outer ring were delineated in the Si crystal wafer. At the surface of the Si crystal, vertical-horizontal line (V-H line) defects and windmill defects (W-defects) were formed instead of OISF. The families of growth planes and directions were expressed as {011} and for the V-H line and {010} and for W-defects, respectively. In addition to V-H line defects and W-defects, pits or voids and Si oxide with dissolved Cu were found in the Si crystal wafer.展开更多
Muscle biopsies from two female patients with systemic sclerosis (SS) and an inflammatory myopathy were studied ultrastructurally in relation to the possible presence of apoptosis in skeletal muscle fibers. Undergoing...Muscle biopsies from two female patients with systemic sclerosis (SS) and an inflammatory myopathy were studied ultrastructurally in relation to the possible presence of apoptosis in skeletal muscle fibers. Undergoing apoptosis showed characteristic morphological features of this process, including chromatin aggregation as well as nuclear and sarcoplasmic partition into membrane bound-vacuoles (apoptotic bodies) which contained autophagosomes, mitochondria, isolated myofilaments and nuclear material. Vacuoles exhibited different diameters and were covered by single membranes, appearing beneath basement membrane. Apoptosis occurred in some fiber segments as in necrosis or included whole atrophied fibers. These results indicate that apoptosis coexists with necrosis in the inflammatory myopathy of SS.展开更多
In the present study, the morphological and ultrastructural characteristics of mesenchymal stem cells (MSCs) induced towards osteogenic, adipogenic, and chondrogenic lineages were investigated. The main objective of t...In the present study, the morphological and ultrastructural characteristics of mesenchymal stem cells (MSCs) induced towards osteogenic, adipogenic, and chondrogenic lineages were investigated. The main objective of this paper was to focus on the differentiation capacity of ovine [oMSCs] and equine MSCs [eMSCs]. Bone marrow [BM] MSCs were isolated from ovine and equine patients, expanded in monolayer culture and induced into osteogenic, adipogenic and chondrogenic differentiation. For chondrogenic differentiation, cells were cultured in micromass culture. Also, their ultrastructural phenotypes were studied by transmission electron microscopy [TEM]. This study was aimed to provide an indepth morphological description of BM-derived ovine and equine MSCs induced towards three lineages, it demonstrated that TEM analysis is useful in elucidating detailed structural information.展开更多
The skin contains various populaions of stem cells, but its characterization has been hampered by lack of markers and unclear location. The hair follicle has a niche for stem cells called a “bulge” which acts as a r...The skin contains various populaions of stem cells, but its characterization has been hampered by lack of markers and unclear location. The hair follicle has a niche for stem cells called a “bulge” which acts as a reservoir of multipotent stem cells. In the study reported here, an immunohistochemical and immunofluorescence analysis was performed on mouse and human tissues in order to determine the possible presence of stem cells of hair follicle through cytokeratin 15 (CK15), CD34, and CD200 markers identified as crucial to the stem cells and to identify the bulge region. Mouse (n = 7) and human (n = 7) skin samples were used. The expression of proteins was determined by the indirect immunoperoxidase technique and a secondary antibody bound to a fluorochrome. The specificity of staining was evaluated by negative controls. The results revealed that the stem cells associated with CD34 and CD200 antibodies were differentially expressed in the interfollicular epidermis, sebaceous glands, and bulge region, indicating that, in mice, CD34 and, in humans, CD200 are more specific than CK15 in detecting bulge cells. It also suggests that CD34 is specific for mouse bulge cells, while CD200 might have specificity for progenitor cells and partially differentiated cells in humans.展开更多
Provisional prosthetic restoration materials are exposed to oral cavity producing on the surface biofilm where different factors such as surface roughness and porosity can condition their formation and organization an...Provisional prosthetic restoration materials are exposed to oral cavity producing on the surface biofilm where different factors such as surface roughness and porosity can condition their formation and organization and can create stagnation areas that promote the bonding of organic particles, thus facilitating the formation and maturation of the biofilm. The purpose of this study was to compare surface roughness of two provisional prosthetic restorations materials and their bacterial susceptibility. In this study, two provisional restoration materials were used in two groups, A polymethyl methacrylate acrylic (NicTone MDC DENTAL) and B bis-acryl resin (Protemp 4 ESPE 3M). A total of 80 samples (40 samples of each material) were in thick plates of 10 × 10 mm and 2 mm high. 20 samples of each material were polished, while 20 were left unpolished. Subsequently, the samples were observed by Atomic Force Microscopy for their evaluation of surface roughness. The values were analyzed with t-test, Mann-Whitney U test and Kruskal Wallis test. The samples were microbiologically inoculated with the strains obtained and identified from a provisional polymethyl methacrylate acrylic restoration in a patient, in order to observe bacterial adhesion using a Scanning Electron Microscope. Two strains, Enterococcus faecalis and Pseudomona luteola, were identified. The presence of the microorganisms was observed on the surface of both materials, either polished or unpolished, with a lower level of microorganism adhesion found on the bis-acrylic resin. There was a significant difference about surface roughness in the groups A and B with p -8). We found that the polished bis-acrylic resin showed lower surface roughness and bacterial adhesion in comparison with the polymethyl methacrylate.展开更多
The aim of this study is to evaluate the maximum and minimum distances between the model and the cast crown of three techniques using Scanning Electron Microscopy (SEM). Three technique groups were used for this study...The aim of this study is to evaluate the maximum and minimum distances between the model and the cast crown of three techniques using Scanning Electron Microscopy (SEM). Three technique groups were used for this study: group A (control), traditional manual wax patterns;group B, dipping wax patterns;group C, resin patterns made with CAD/CAM. For each group, 10 samples were made using the same model, and then metal cast. Marginal accuracies of the samples were evaluated by performing gap measurements using SEM with a magnification of 1200× (minimum distance). The data were statistically analyzed using the one-way analysis of variance (ANOVA) at the 0.05 significance level. The average (standard deviation) of the minimum distance [μm] was 22.5 (12.1), 9.9 (4.3), and 14.7 (6.6), in groups A, B, and C, respectively. The average standard deviation of gap area [μm2] was 21667.2 (3476.4), 9906.4 (1512.1), and 16048.8 (8123). In the minimum distance comparison, groups A and B (p = 0.006) showed statistically significant results. In the gap area comparison, there was no statistical significance among groups A, B, and C (p = 0.174). The marginal adaptations of all three techniques were within a reported clinically acceptable range of margin.展开更多
Objectives: To compare the distribution of chemical elements among the carious and normal enamel layers on teenagers, using energy dispersive X ray spectrometer (EDS Rx). Materials and Methods: The EDS Rx analyzer is ...Objectives: To compare the distribution of chemical elements among the carious and normal enamel layers on teenagers, using energy dispersive X ray spectrometer (EDS Rx). Materials and Methods: The EDS Rx analyzer is integrated to scanner electron microscope. The macro and mi-croelements were made in 30 premolars of teenager: 14 carious enamel layers and 16 normal enamel layers. Results: The quantitative and qualitative microanalyses of macro and microele-ments were found between the enamel layers of carious and normal premolar in term of variation and concentration expressed in percentage atomic weight. The statistical data analysis of ANOVA showed that the macroelements [C, Ca, P] and the microelements [Al, Cl, Mg, Na] were significantly different (P < 0.05) while, the macro [O] and the microelements [In, Si, W, S] were not significantly different (P < 0.05) among the carious and normal enamel layers. Moreover, the microelements Sb, Ba, Br, I, Ir, K, Pt, Sc, Sr, Sn and Yb were absent in carious enamel layers and present in normal enamel layers. Conclusion: The macro and microelements differ in composition and variation from the external to the internal enamel layers between the carious and the normal premolars. However, the deficiency or excess of these elements in the enamel layers determines the degree of susceptibility to carious and other dental disease. Clinical Relevance: The carious enamel in dental structure could be a major dental problem due to the deficiency or excess of macro and microele-ments which are responsible for secondary or recurrent caries, discoloration, pulpal inflammation, re-infection, abscess in jaw bone and dental disease.展开更多
文摘Pure Mg wires with a maximum cumulative area reduction of 98% were obtained by successful cold drawing. Mechanical properties, microstructures and texture evolution of the as-drawn wires were investigated by tensile tests, transmission electron microscopy (TEM) and electron backscattering diffraction (EBSD). Depended on the mechanical properties and microstructure evolution, continuous dynamic recrystallization (DRX) had taken place during the cold drawing process. DRX during cold deformation has not been reported in other literatures before.
文摘Diagnosis of Trypanosoma brucei rhodesiense human African trypanosomiasis requires demonstration of parasites in body fluids by microscopy. The microscopy methods that are routinely used are difficult to deploy in resource-limited settings due to practical challenges, including lengthy and tedious procedures, and the need for specific equipment to centrifuge samples in glass capillary tubes. We report here on a study that was conducted in a rural region of eastern Uganda to evaluate new methods that take advantage of a field-deployable LED fluorescence microscope. Examination of acridine orange-stained blood smears by LED fluorescence microscopy resulted in a diagnostic accuracy that was similar to that of routine methods, while the time needed to identify parasites was shortened significantly. These findings make these new microscopy methods attractive alternatives to procedures that are currently used for diagnosis of T. b. rhodesiense human African trypanosomiasis.
文摘Background: Confirmatory diagnosis of Trypanosoma brucei gambiense human African trypanosomiasis (HAT) is based on demonstration of parasites by microscopy. However, the sensitivity of routine microscopy methods is very low, and many cases are missed and left untreated. A clinical study was conducted in the Democratic Republic of the Congo to evaluate the accuracy of improved microscopy methods in diagnosis of HAT. These included examination by fluorescence microscopy (FM) of acridine orange (AO) stained smears of whole blood and smears made following a new procedure for concentrating trypanosomes by selective lysis of red blood cells (RBC). Methodology/Principal Findings: Venous blood was collected from 213 HAT cases, 101 HAT suspects and 95 controls and used to determine the accuracy of four microscopy methods: bright field microscopy of Giemsa-stained thick blood smears, FM of AO-stained thick blood smears, FM of AO-stained thick blood smears prepared after RBC lysis and concentration, and FM of AO-stained thin blood smears prepared after RBC lysis and concentration. The sensitivity of FM using thick blood smears stained with AO was 3 times higher than bright field microscopy using Giemsa-stained thick blood smears [19.7% (95% CI: 14.9% - 25.6%) versus 6.1% (95% CI: 3.6% - 10.2%)]. When the RBC lysis and concentration procedure was included, sensitivity of the test was further enhanced to 23.0% (95% CI: 17.9% - 29.1%) with thick blood smears and 34.3% (95% CI: 28.2% - 40.9%) with thin blood smears. Specificity of all four microscopy methods was 100% (95% CI: 96.1% - 100.0%). However, the miniature anion exchange chromatography technique (mAECT) and capillary tube centrifugation (CTC) method remained more sensitive. Conclusions: These new methods have practical advantages, including shorter staining time, ease of demonstration of parasites, and the possibility of archiving slides. They could, therefore, be alternative methods to improve case detection where concentration procedures such as mAECT or CTC are not performed.
文摘Melanosomes, isolated by centrifugal separation from culture broth of B16 melanoma cells derived from mouse, were observed by scanning electron microscopy (SEM), and by transmission electron microscopy (TEM). Some interesting structural features were found inside and outside of the melanosomes. By SEM observation, the melanosomes were ellipsoid shape, their surface was not smooth and was covered with rough substructure, 10 to 20 nm particles. By TEM, uneven structure and micro particles were observed in the melanosomes. Furthermore, three-dimensional analysis was tried by using the ultra-high voltage electron microscopy(UHVEM). Micrographs of the melanosomes were taken at various tilted angles by UHVEM, after preparing 500 nm thickness specimens stained with lead citrate. From the micrographs collected, the three-dimensional structures were reconstructed by using i-mode software. Melanin stained by lead and non stained parts was clearly observed in the reconstructed structure. Non stained parts were round, regular size, and distributed widely in the melanosomes.
文摘In the present study, histopathology of three varieties of sesame TS 3, TS 5 and SG 27 infected with Alternaria alternata was carried out to understand the mechanism of fungal infection and penetration in sesame plant as well as to determine the histological manifestation in sesame cells by light microscopy. Fungus was identified in infected tissues as a dark bluish black with toluidine blue O staining. Light microscopic examination of sesame stem showed that the fungus was present in epidermis, hypodermis and cortical parenchyma tissue as the symptoms became visible by naked eye ten days after inoculation (DAI). As the disease progress, the fungus moved from cortical parenchyma to vascular bundle, xylem and phloem. Later on, it completely overlapped the vascular bundle and entered in pith. When necrotic lesion appeared, fungus was present abundantly in epidermis, hypodermis, cortical parenchyma, vascular bundles and in pith. Due to its excessive growth and complete overlapping of cells, disorganization or destruction of cells of sesame took place. It was concluded that the Alternaria alternata was not a tissue limited pathogen instead of this it spread in to all tissues of stem from epidermis to pith.
文摘The Scanning Electron Microscopy (SEM) and Optical Microscopy (OM) with integrated digital camera are techniques that are used in the present investigation, for the morphological characterization of a new composite material called “organic polymer concrete” in which microparticles added fibers and polyethylene terephthalate (PET) recycling mechanically (RM). Polymer concrete (PC) is a new composite material (MC) in the application considered as an alternative material of construction in which reinforcement particles are recycled polymers which have approximately the same dimensions in all directions. Therefore, the particles can be rods, spheres, chips and many other shapes whose appearance reasons are about 10 microns. These MC, the size, shape and distribution and the ratio and the modulus of the particles affect the properties of the material.
文摘Solid polymer electrolytes (SPEs) of polyacrylamide-co-acrylic acid (PAA) as the polymer host and zinc acetate (ZnA) as an ionic dopant were prepared using a single solvent by the solution casting technique. The amorphous and crystalline structures of film were investigated by X-ray diffraction (XRD). The surface morphology of samples was examined by scanning electron microscopy (SEM). The composition and complex formation of films were characterized by Fourier transform infrared (FTIR) spectroscopy. The conductivity of the PAA-ZnA films was determined by electrochemical impedance spectroscopy. According to the XRD and FTIR analyses, all electrolyte films were in amorphous state and the existence of interaction between Zn2+ cations and the PAA structure confirms that the film was successfully prepared. The SEM observations reveal that the electrolyte films appeared to be rough and flat with irregularly shaped surfaces. The highest ionic conductivity (σ) of 1.82 × 10-5 Scm-1 was achieved at room temperature (303 K) for the sample containing 10 wt % ZnA.
文摘Urea-formaldehyde (UF) resin is widely used as an adhesive for the manufacture of a range of wood and fiber based products. Although the microstructure of this resin has been examined at high resolution by field-emission scanning electron microscopy and atomic force microscopy, transmission electron microscopy (TEM) has thus far not been used, perhaps because of difficulties in ultrathin sectioning this resin in cured (polymerized) state. In the technical note presented here, a novel sample preparation method is described which enabled us to examine the microstructural morphology of UF resin by transmission electron microscopy in ultrathin sections, revealing the presence of spherical particles within the resin. Our initial attempt to ultrathin section the resin directly was not successful as it was too brittle to trim blocks for sectioning. Then, we developed a sample preparation technique that involved impregnation ofPinus radiatawood tissues with the UF resin, and then embedding of resin impregnated wood tissues with Spurr’s low viscosity embedding medium, which has been widely employed in plant and wood ultrastructure work. The TEM images illustrated and the information on the microstructural morphology of the UF resin presented are based on this novel sample preparation approach.
文摘An epitaxial SixGey layer on a silicon substrate was quantitatively evaluated using rocking curve (RC) and reciprocal space map (RSM) obtained by powder X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) in conjunction with transmission electron microscopy (TEM), and EDS in conjunction with scanning electron microscopy (SEM). To evaluate the relative deviation of the quantitative analysis results obtained by the RC, RSM, SEM/EDS, and TEM/EDS methods, a standard sample comprising a Si0.7602Ge0.2398 layer on a Si substrate was used. The correction factor (K-factor) for each technique was determined using multiple measurements. The average and standard deviation of the atomic fraction of Ge in the Si0.7602Ge0.2398 standard sample, as obtained by the RC, RSM, TEM/EDS, and SEM/EDS methods, were 0.2463 ± 0.0016, 0.2460 ± 0.0015, 0.2350 ± 0.0156, and 0.2433 ± 0.0059, respectively. The correction factors for the RC, RSM, TEM/EDS, and SEM/EDS methods were 0.9740, 0.9740, 1.0206, and 0.9856, respectively. The SixGey layer on a silicon substrate was quantitatively evaluated using the RC, RSM, and EDS/TEM methods. The atomic fraction of Ge in the epitaxial SixGey layer, as evaluated by the RC and RSM methods, was 0.1833 ± 0.0007, 0.1792 ± 0.0001, and 0.1631 ± 0.0105, respectively. After evaluating the results of the atomic fraction of Ge in the epitaxial layer, the error was very small, i.e., less than 3%. Thus, the RC, RSM, TEM/EDS, and SEM/EDS methods are suitable for evaluating the composition of Ge in epitaxial layers. However, the thickness of the epitaxial layer, whether the layer is strained or relaxed, and whether the area detected in the TEM and SEM analyses is consistent must be considered.
文摘Transmission electron microscopy (TEM) is a very powerful technique for materials characteriza-tion, providing information relating to morphology, composition, and crystal structure. Selected area diffraction patterns (SADPs) are crystallographic data that can be obtained using a TEM in-strument. Conventional identification through SADP/TEM is tricky and tedious, thereby increasing the difficulty of phase identification. To establish a procedure for phase identification of known and unknown phases, in this study we examined two samples: one, a known phase, was Si with alignment;the other, unknown, was the TixOy phase at the 96.4Au-3Ni-0.6Ti interlayer/ yttria-stabilized zirconia (YSZ) interface of a steel/96.4Au-3Ni-0.6Ti interlayer/YSZ joint. The procedures for phase identification of the known and unknown phases are described herein using a series of SADPs and energy dispersive spectrometry within TEM that would be useful for general researchers.
文摘Acid rain (AR) has been reported to induce stress in plants affecting its productivity, growth, flowering and physiology. The molecular changes induced in plants due to the effect of acid rain or acid induced orientation or chloroplast streaming remains largely unknown. Therefore, in the current study we report for the first time the static and permanent changes in the cell of the medicinal plant Bacopa monnieri L. due to sulphur-simulated acid rain (S-SiAR). AR induced effects witnessed by the reduction of the size of starch granules and chloroplast, amount of the granules per unit area, dissolving cell walls, breaking the normal fiber, salt-induced strain in the various components of the cell. Effect of starch granule and chloroplast due to S-SiAR was analyzed using light, confocal and scanning electron microscopic techniques. The elements viz. potassium and magnesium present in the chloroplasts reveal acidic pH due to effect of S-SiAR observed by the ionization of Mg and K (to Mg2+ and K+), in which K+ induced by the effects of S-SiAR revealed a net negative Nernst potential of about -87.55 mV. Calcium is mainly present on the cell walls and responsible for binding of starch granules become ionized to Ca2+ on interacting with AR indicated by the altered Nernst potential of +137.04 mV. A net potential difference may cause the above streaming of chloroplast towards the large starch granules. From this study, we report AR-induced physiological changes in medicinal plant Bacopa monnieri L. for the first time.
文摘The procedure to measure liposome in aqueous solution has been examined using atomic force microscope (AFM). We concluded a chemical modified silicon wafer (substrate for AFM observation of liposome) with 3-aminopropyltrieth-oxysilane (APTES) which enabled us to scan anionic liposome softly in water because they were keeping structures as vesicles and stably adsorbed on the substrate by electrostatic force. From captured AFM topographic images, we counted the amount of liposome and analyzed the distribution of mean diameters, which were corrected by an approximated curve of the tip shape. We discussed the method of effective evaluation as practical analysis and its problems for robust analysis.
文摘In this contribution, an experimental setup to investigate the defect luminescence between 0.72 - 0.85 eV of single defects in Silicon by optical microscopy is introduced. For this purpose, an optical microscope is equipped with an InGaAs CCD detector and a longpass filter with a cut-off wavelength at 1450 nm in order to filter out the band-to-band luminescence at around 1.1 eV. Grain boundaries showing homogeneous distributed defect luminescence can be localized at a μm-scale.
文摘Bulk Czochralski silicon crystals were decorated with Cu and characterized by transmission electron microscopy (TEM) with energy-dispersive spectroscopy (EDS), atomic force microscopy (AFM), optical microscopy (OM), scanning electron microscopy (SEM), and photoluminescence spectroscopy (PL). The vacancy-type core, oxidation-induced stacking faults (OISF) ring, nearly defect-free ring, and self-interstitial-type rich outer ring were delineated in the Si crystal wafer. At the surface of the Si crystal, vertical-horizontal line (V-H line) defects and windmill defects (W-defects) were formed instead of OISF. The families of growth planes and directions were expressed as {011} and for the V-H line and {010} and for W-defects, respectively. In addition to V-H line defects and W-defects, pits or voids and Si oxide with dissolved Cu were found in the Si crystal wafer.
文摘Muscle biopsies from two female patients with systemic sclerosis (SS) and an inflammatory myopathy were studied ultrastructurally in relation to the possible presence of apoptosis in skeletal muscle fibers. Undergoing apoptosis showed characteristic morphological features of this process, including chromatin aggregation as well as nuclear and sarcoplasmic partition into membrane bound-vacuoles (apoptotic bodies) which contained autophagosomes, mitochondria, isolated myofilaments and nuclear material. Vacuoles exhibited different diameters and were covered by single membranes, appearing beneath basement membrane. Apoptosis occurred in some fiber segments as in necrosis or included whole atrophied fibers. These results indicate that apoptosis coexists with necrosis in the inflammatory myopathy of SS.
文摘In the present study, the morphological and ultrastructural characteristics of mesenchymal stem cells (MSCs) induced towards osteogenic, adipogenic, and chondrogenic lineages were investigated. The main objective of this paper was to focus on the differentiation capacity of ovine [oMSCs] and equine MSCs [eMSCs]. Bone marrow [BM] MSCs were isolated from ovine and equine patients, expanded in monolayer culture and induced into osteogenic, adipogenic and chondrogenic differentiation. For chondrogenic differentiation, cells were cultured in micromass culture. Also, their ultrastructural phenotypes were studied by transmission electron microscopy [TEM]. This study was aimed to provide an indepth morphological description of BM-derived ovine and equine MSCs induced towards three lineages, it demonstrated that TEM analysis is useful in elucidating detailed structural information.
文摘The skin contains various populaions of stem cells, but its characterization has been hampered by lack of markers and unclear location. The hair follicle has a niche for stem cells called a “bulge” which acts as a reservoir of multipotent stem cells. In the study reported here, an immunohistochemical and immunofluorescence analysis was performed on mouse and human tissues in order to determine the possible presence of stem cells of hair follicle through cytokeratin 15 (CK15), CD34, and CD200 markers identified as crucial to the stem cells and to identify the bulge region. Mouse (n = 7) and human (n = 7) skin samples were used. The expression of proteins was determined by the indirect immunoperoxidase technique and a secondary antibody bound to a fluorochrome. The specificity of staining was evaluated by negative controls. The results revealed that the stem cells associated with CD34 and CD200 antibodies were differentially expressed in the interfollicular epidermis, sebaceous glands, and bulge region, indicating that, in mice, CD34 and, in humans, CD200 are more specific than CK15 in detecting bulge cells. It also suggests that CD34 is specific for mouse bulge cells, while CD200 might have specificity for progenitor cells and partially differentiated cells in humans.
文摘Provisional prosthetic restoration materials are exposed to oral cavity producing on the surface biofilm where different factors such as surface roughness and porosity can condition their formation and organization and can create stagnation areas that promote the bonding of organic particles, thus facilitating the formation and maturation of the biofilm. The purpose of this study was to compare surface roughness of two provisional prosthetic restorations materials and their bacterial susceptibility. In this study, two provisional restoration materials were used in two groups, A polymethyl methacrylate acrylic (NicTone MDC DENTAL) and B bis-acryl resin (Protemp 4 ESPE 3M). A total of 80 samples (40 samples of each material) were in thick plates of 10 × 10 mm and 2 mm high. 20 samples of each material were polished, while 20 were left unpolished. Subsequently, the samples were observed by Atomic Force Microscopy for their evaluation of surface roughness. The values were analyzed with t-test, Mann-Whitney U test and Kruskal Wallis test. The samples were microbiologically inoculated with the strains obtained and identified from a provisional polymethyl methacrylate acrylic restoration in a patient, in order to observe bacterial adhesion using a Scanning Electron Microscope. Two strains, Enterococcus faecalis and Pseudomona luteola, were identified. The presence of the microorganisms was observed on the surface of both materials, either polished or unpolished, with a lower level of microorganism adhesion found on the bis-acrylic resin. There was a significant difference about surface roughness in the groups A and B with p -8). We found that the polished bis-acrylic resin showed lower surface roughness and bacterial adhesion in comparison with the polymethyl methacrylate.
文摘The aim of this study is to evaluate the maximum and minimum distances between the model and the cast crown of three techniques using Scanning Electron Microscopy (SEM). Three technique groups were used for this study: group A (control), traditional manual wax patterns;group B, dipping wax patterns;group C, resin patterns made with CAD/CAM. For each group, 10 samples were made using the same model, and then metal cast. Marginal accuracies of the samples were evaluated by performing gap measurements using SEM with a magnification of 1200× (minimum distance). The data were statistically analyzed using the one-way analysis of variance (ANOVA) at the 0.05 significance level. The average (standard deviation) of the minimum distance [μm] was 22.5 (12.1), 9.9 (4.3), and 14.7 (6.6), in groups A, B, and C, respectively. The average standard deviation of gap area [μm2] was 21667.2 (3476.4), 9906.4 (1512.1), and 16048.8 (8123). In the minimum distance comparison, groups A and B (p = 0.006) showed statistically significant results. In the gap area comparison, there was no statistical significance among groups A, B, and C (p = 0.174). The marginal adaptations of all three techniques were within a reported clinically acceptable range of margin.
文摘Objectives: To compare the distribution of chemical elements among the carious and normal enamel layers on teenagers, using energy dispersive X ray spectrometer (EDS Rx). Materials and Methods: The EDS Rx analyzer is integrated to scanner electron microscope. The macro and mi-croelements were made in 30 premolars of teenager: 14 carious enamel layers and 16 normal enamel layers. Results: The quantitative and qualitative microanalyses of macro and microele-ments were found between the enamel layers of carious and normal premolar in term of variation and concentration expressed in percentage atomic weight. The statistical data analysis of ANOVA showed that the macroelements [C, Ca, P] and the microelements [Al, Cl, Mg, Na] were significantly different (P < 0.05) while, the macro [O] and the microelements [In, Si, W, S] were not significantly different (P < 0.05) among the carious and normal enamel layers. Moreover, the microelements Sb, Ba, Br, I, Ir, K, Pt, Sc, Sr, Sn and Yb were absent in carious enamel layers and present in normal enamel layers. Conclusion: The macro and microelements differ in composition and variation from the external to the internal enamel layers between the carious and the normal premolars. However, the deficiency or excess of these elements in the enamel layers determines the degree of susceptibility to carious and other dental disease. Clinical Relevance: The carious enamel in dental structure could be a major dental problem due to the deficiency or excess of macro and microele-ments which are responsible for secondary or recurrent caries, discoloration, pulpal inflammation, re-infection, abscess in jaw bone and dental disease.
