In situ observation of the dissolution kinetics of Al_(2)O_(3) particles in CaO–Al_(2)O_(3)–SiO_(2) slags using laser confocal scanning microscopy

The dissolution kinetics of Al_(2)O_(3) in CaO-Al_(2)O_(3) SiOslags was studied using a high-temperature confocal scanning laser microscope at 1773 to 1873 K.The results show that the controlling step during the Al_(2)O_(3) dissolution was the diffusionin molten slag.It was found that the dissolution curves of Al_(2)O_(3) particles were hardly agreed with the traditional boundary layer diffusion model with the increase of the CaO/Al_(2)O_(3) ratio of slag.A modified diffusion equation considering slag viscosity was developed to study the dissolution mechanism of Al_(2)O_(3) in slag.Diffusion coefficients of Al_(2)O_(3) in slag were calculated as 2.8×10to 4.1×10m~2/s at the temperature of 1773-1873 K.The dissolution rate of Al_(2)O_(3) increased with higher temperature,CaO/Al_(2)O_(3),and particle size.A new model was shown to be v_(Al_(2)O_(3))=0.16×r_(0)^(1.58)×x^(3.52)×(T-T_(mp))^(1.11)to predict the dissolution rate and the total dissolution time of Al_(2)O_(3) inclusions with various sizes,where vAl_(2)O_(3) is the dissolution rate of Al_(2)O_(3) in volume,μm^(3)/s;x is the value of CaO/Al_(2)O_(3) mass ratio;R_(0) is the initial radius of Al_(2)O_(3),μm;T is the temperature,K;T_(mp) is the melting point of slag,K.

Application of Scanning Acoustic Microscopy for Detection of Dental Caries Lesion

Introduction: A scanning acoustic microscope (SAM) is an apparatus for imaging acoustic properties. This apparatus can non-invasively and rapidly evaluate the hardness of materials in the elastic region. This device shows great potential for the diagnosis of dental caries in the clinical setting. However, since the tissue elastic modulus measured using a SAM is a property of the elastic region and the Knoop hardness is a property of the plastic region, the hardness properties differ completely. Therefore, we investigated whether the acoustic impedance measured using a SAM is related to the Knoop hardness, which is used as the standard for removal of carious dentin. Method: Polished sections were prepared from 20 extracted carious wisdom teeth. The acoustic impedance and Knoop hardness were measured for each section. In addition to comparing carious and healthy dentin in SAM images, we evaluated the difference between the carious and healthy dentin in terms of the acoustic impedance and Knoop hardness. We also evaluated the correlation between the Knoop hardness and acoustic impedance. Results: The SAM images were visualized as two-dimensional color images based on the acoustic impedance values. The mean acoustic impedance of carious dentin was significantly lower than that of healthy dentin, showing a similar trend as Knoop hardness. A strong correlation was observed between the two. Discussion: The acoustic impedance values obtained through acoustic microscopy differed significantly between carious and sound dentin. Both types of dentins were visualized using two-dimensional color images. A strong correlation was observed between the acoustic impedance value, which indicates the hardness of the elastic region, and the Knoop hardness, which indicates the hardness of the plastic region. The results of the present study indicate that acoustic impedance accurately reflects the hardness of dentin.

Chalkiness Characters and Scanning Electron Microscope Observation of Rice Grain Endosperm of Japonica Varieties in Southern Henan

Chalkiness characters affect not only the grain appearance,milling,eating and cooking qualities but also the grain nutritional quality in rice,thus it is one of the most important traits in rice. It is very important for us to investigate the relation of the chalkiness formation and the development of endosperm structure and starch granule of different rice varieties. Here,we have investigated the chalkiness characters such as chalkiness rate,chalkiness degree and chalkiness area in 15 japonica rice varieties from southern Henan. Furthermore,the endosperm structure and starch granules of rice grain were also observed with scanning electron microscope. The results showed that the 15 japonica varieties have a significantly linear relationship between the chalkiness rate and chalkiness degree. Among the varieties,the biggest difference is the chalkiness rate,the second is the chalkiness area,and the last is the chalkiness degree. Moreover,there is a certain correlation between the distribution of starch granules,the arrangement of endosperm cells and the occurrence of grain chalkiness in the different rice varieties. For the same variety,the starch granules of chalky and non-chalky grains have obvious difference,while the starch granules from the transparent part of chalky rice and non-chalky rice do not have significant difference. The results would provide useful references for the improvement of grain quality in rice.

A stage-scanning laser confocal microscope and protocol for DNA methylation sequencing

Recent understanding of the role of epigenetic regulation in health and disease has necessitated the development of newer and efficient methods to map the methylation pattern of target gene. In this article we report construction of a stage-scanning laser confocal microscope (SLCM) and associated protocol that determines the methylation status of target gene. We have adapted restricted Sanger’s sequencing where fluorescine labeled primers and dideoxy guanine fraction alone are used for target amplification and termination at cytosine positions. Amplified ssDNA bands are separated in 6% denaturing PAGE and scanned using SLCM to sequence the positions of methylated cytosines. We demonstrate that our me- thodology can detect < 100 femtomoles of DNA, and resolve the position of cytosine within ± 2 nucleotide. In a calibration run using a designer DNA of 99 bases, our methodology had resolved all the 11 cytosine positions of the DNA. We have further demonstrated the utility of apparatus by mapping methylation status in the Exon-1 region of a gene, E-Cadherin, in the plasma DNA sample of a healthy subject. We believe our approach constitute a low cost alternative to conventional DNA sequencers and can help develop methylation based DNA biomarkers for the diagnosis of disease and in therapeutics.

A novel phase-sensitive scanning near-field optical microscope

Phase is one of the most important parameters of electromagnetic waves. It is the phase distribution that determines the propagation, reflection, refraction, focusing, divergence, and coupling features of light, and further affects the intensity distribution. In recent years, the designs of surface plasmon polariton （SPP） devices have mostly been based on the phase modulation and manipulation. Here we demonstrate a phase sensitive multi-parameter heterodyne scanning near-field opti- cal microscope （SNOM） with an aperture probe in the visible range, with which the near field optical phase and amplitude distributions can be simultaneously obtained. A novel architecture combining a spatial optical path and a fiber optical path is employed for stability and flexibility. Two kinds of typical nano-photonic devices are tested with the system. With the phase-sensitive SNOM, the phase and amplitude distributions of any nano-optical field and localized field generated with any SPP nano-structures and irregular phase modulation surfaces can be investigated. The phase distribution and the interference pattern will help us to gain a better understanding of how light interacts with SPP structures and how SPP waves generate, localize, convert, and propagate on an SPP surface. This will be a significant guidance on SPP nano-structure design and optimization.

Confocal Laser Scanning Microscope Evaluation of Early Bacterial Colonization on Zirconium Oxide and Titanium Surfaces:An in vivo Study

To investigate the bacterial colonization on zirconium oxide and titanium surfaces in vivo quantitatively using a confocal laser scanning microscope （CLSM）. Ten samples of zirconium oxide ceramic and commercially pure titanium were fabricated and polished using silicon carbide abrasive paper. One sample from each group was evaluated topographic pattern under a scanning electron microscope. One sample from each group was to evaluate roughness using a profilometer. Eight volunteers were selected. The samples were cemented at the buccal surfaces of upper first molars. All samples were removed after 48 hours, immersed in SYTO-9 and propidium iodide fluorescent to stain for adherent bacteria and obseIved with CLSM. Fewer bacteria were observed in zirconia group than titanium group. However, there was no statistical difference between two groups. The experimental results demonstrate that zirconium oxide may be considered as a promising material for dental implant abutments.

Scanning tunnelling microscope studies of growth of RuO2（110） thin layer on Ru（0001）

This paper reports that the growth of RuO2（110） thin layer growth on Ru（0001） has been investigated by means of scanning tunnelling microscope （STM）. The STM images showed a domain structure with three rotational domains of RuO2（110） rotated by an angle of 120°. The as-grown RuO2（110） thin layer is expanded from the bulk-truncated RuO2（110） due to the large mismatch between RuO2（110） and the Ru（0001） substrate. The results also indicate that growth of RuO2（110） thin layer on the Ru（0001） substrate by oxidation tends first to formation of the Ru-O （oxygen） chains in the [001] direction of RuO2 （110）.

Fabrication of grating-like polystyrene latex monolayer structure as three-dimensional calibration standards for scanning probe microscope

This paper illuminates the preparation of grating-like polystyrene latex monolayer structure, which can minimize the effects of the size deviation of spheres and the defect transfer on the accuracy as calibration samples for micro-scopes. The latex films are grown on freshly cleaved mica substrates by vertical deposition method. The concentration dependence of the structure and the topography of latex films is characterized by optical microscope, ultraviolet- visible transmission spectrum and scanning probe microscope. The origination of such a grating-like structure is also discussed.

Quantum Dots as Fluorescent Labels for Detection of Heat Shock Protein in Tumor Tissue Using Laser Scanning Confocal Microscope

A new Quantum Dots（Qdots） nanocrystal composed of semiconductor core and zinc sulfide shell, and its feasibility as labels in immunofluorescence analysis for the imaging of tumor biomarkers by laser scanning confocal microscope（LSCM） was investigated. Qdots taged by mercaptoacetic acid were conjugated with second antibody, then imaging differences of Heat Shock Proteins 70（HSP70） in renal carcinoma tissure sections with immunofluorescence analysis method using Qdots bioconjugates and conventional organic dye FITC were observed by LSCM to assess the brightness and opticalstability of Qdots. The experimental results showed Qdots bioconjugates achieved the better results in demonstrating HSP70 with more brighter color and more clear picture than FITC labels. Moreover, the label signals of Qdots did not fade clearly after continued exposure to a 488 nm laser for 1 h. The Qdots bioconjugates have good feasibility in immunofluorescence analysis for the bioimaging by LSCM.

Vibration Compensation for Scanning Tunneling Microscope

The influence of vibration is already one of main obstacles for improving the nano measuring accuracy.The techniques of anti-vibration,vibration isolation and vibration compensation become an important branch in nano measuring field.Starting with the research of sensitivity to vibration of scanning tunneling microscope(STM),the theory,techniques and realization methods of nano vibration sensor based on tunnel effect are initially investigated,followed by developing the experimental devices.The experiments of the vibration detection and vibration compensation are carried out.The experimental results show that vibration sensor based on tunnel effect is characterized by high sensitivity,good frequency characteristic and the same vibratory response characteristic consistent with STM.

Qualitative analysis of re mineralized carious lesions subjected to fluoride supplement through confocal laser scanning microscope

Aim: 1] Comparative evaluation of the linear depth of induced remineralized lesions after subjecting to fluoride supplements and 2] To assess the average fluorescence at both the demineralized and the remi-neralized zones in all the three study groups under confocal laser scanning microscope. Method: Forty five sound human premolars extracted for orthodon-tic reasons were decoronated 1 mm below the ce-mento-enamel junction and coated with nail varnish except for a 3 × 3 mm window on the buccal surface. The samples were placed in 50 ml of de mineralizing solution at pH 4.6 for 96 hours. Following deminera-lization, the lower half of the 3 × 3 mm window in all the samples were covered with nail varnish to serve as control. The samples were randomly divided into three groups of fifteen teeth each (n = 15) and speci-mens in group A[Nfd] were remineralized using non-fluoridated dentifrice [control], those in groups B [Fd5] and group C [Fd10] using 500 ppm and 1000 ppm of fluoride containing dentifrice, respectively. The specimens were subjected to a 20 day reminera-lization treatment regimen and were sectioned into 100 μm thick sections and two images were captured on the buccal surface from either side of the midpoint of occluso-cervical length using confocal laser scan-ning microscope [CLSM]. Results: were tabulated and statistically analyzed by Anova. Study concluded that 1000 ppm fluoridated dentifrice showed a greater degree of remineralization than other groups and confocal laser scanning microscopes gives promising results in the diagnosis of early enamel lesions over the conventional methods.

BAINITE STRUCTURE IN Cu-Zn-Al ALLOY OBSERVED BY SCANNING TUNNELING MICROSCOPE

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Gill surface architecture of mullet, Mugil soiuy (Basilewsky) : A scanning electron microscope study

Specimens of Mugil soiuy were collected from the coastal waters of Bohai Sea in Tianjin. The gillfilaments were cut with fine scissors and soaked for 24h in a fixative consisting of 2.5% glutaralde-hyde in 0.1 mol lphosporic acid buffer. After three washes in a buffer solution the tissue was fixedin a mixture of 1% osmium tetraoxide at 4℃ for 1h. The tissue was dehydrated in graded ethandethanols and dried. The tissue was examined and photographed with an SEM at an accelerating voltage

Optical micro-scanning location calibration of thermal microscope imaging system

A method of micro-scanning location adaptive calibration was proposed, which was real- ized by the digital image micro-displacement estimation. With geometric calculation, this calibration method used the displacement estimation of two thermal microscope images to get the size and direc- tion of each scanning location calibration angle. And each location calibration process was repeated according to the offset given by the system beforehand. The comparison experiments of sequence oversampling reconstruction before and after the micro-scanning location calibration were done. The results showed that the calibration method effectively improved the thermal microscope imaging qual- ity.

Multi-mode Scanning Near-field Optical Microscope

A scanning near-field optical microscope using uncoated fiber tip is described, which can work in transmission and reflection configurations, both capable of working in illumination and collection-mode, so that either transparent or opaque sample can be investigated. Depending on different applications, either constant-gap or constant-height images can be achieved. A compact homemade translator permits to select interested area of sample in the range of 4 mm×4 mm. Working in the constant-height as well as transmission and collection-mode configuration, several kinds of samples such as holographic grating, liposome and zeolite were investigated. The experimental results revealed the dependence of the optical resolution of the SNOM on the tip-sample separation.

Observations of Wood Cell Walls with a Scanning Probe Microscope

Scanning Probe Microscopes (SPMs) observe specimen surfaces with probes by detecting the physical amount of a material between the cantilever and the surface. SPMs have a high resolution and can measure mechanical characteristics such as stiffness, adsorptive properties, and viscoelasticity. These features make it easy to identify the surface structure of complex materials;therefore, the use of SPMs has increased in recent years. Wood cell walls are primarily composed of cellulose, hemicellulose, and lignin. It is believed that hemicellulose and lignin surround the cellulose framework;however, their detailed formation remains unknown. Therefore, we observed wood cell walls via scanning probe microscopy to try to reveal the formation of the cellulose framework. We determined that the size of the cellulose microfibril bundle and hemicellulose lignin module composite was 18.48 nm based on topography and that the size of the cellulose microfibril bundle was 15.33 nm based on phase images. In the viscoelasticity image, we found that the viscoelasticities of each cell wall of the same cell were not the same. This is because the cellulose microfibrils in each cell wall lean in different directions. The angle between the leaning of the cellulose microfibril and the cantilever affects the viscoelasticity measurement.

Micro-Scanning Error Correction Technique for an Optical Micro-Scanning Thermal Microscope Imaging System

An error correction technique for the micro-scanning instrument of the optical micro-scanning thermal microscope imaging system is proposed. The technique is based on micro-scanning technology combined with the proposed second-order oversampling reconstruction algorithm and local gradient image reconstruction algorithm. In this paper, we describe the local gradient image reconstruction model, the error correction technique, down-sampling model and the error correction principle. In this paper, we use a Lena original image and four low-resolution images obtained from the standard half-pixel displacement to simulate and verify the effectiveness of the proposed technique. In order to verify the effectiveness of the proposed technique, two groups of low-resolution thermal microscope images are collected by the actual thermal microscope imaging system for experimental study. Simulations and experiments show that the proposed technique can reduce the optical micro-scanning errors, improve the imaging effect of the system and improve the system's spatial resolution. It can be applied to other electro-optical imaging systems to improve their resolution.

STUDY ON THE SCANNING PROBE MICROSCOPE WITH WIDE MEASURING RANGE

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Experimental Study on Meiotic Spindles and Chromosomes of Mouse Mature (MⅡ) Stage Oocytes under Laser Scanning Confocal Microscopy

Taking the mouse as a model, the experimental method of observing the morphology of meiotic spindles and chromosomes in mature oocytes were investigated in order to evaluate the effects of various interventions on the quality of oocytes accurately and rapidly. Laser scanning confocal microscope （LSCM） was used to examine the meiotic spindles and chromosomes by the technologies of optical section and three-dimensional （3D） image reconstruction. The results showed that the configurations of meiotic spindles and chromosomes could be observed clearly by LSCM. The normal rate of meiotic spindles and chromosomes was 82% and 86% respectively. It was concluded that the LSCM was a valid instrument to observe the meiotic spindles and chromosomes of mature oocytes and could be used as a valid method to evaluate the quality of MⅡocytes.