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.

Solidification process of conventional superalloy by confocal scanning laser microscope

The solidification process of a conventional superalloy, IN718, was investigated by confocal scanning laser microscope （CSLM）. The liquid fraction during solidification was obtained as a function of real time and temperature in reference with the in-situ observation. The characteristics of L→γ transformation were analyzed and the γ growing rate of each stage was also calculated. Scheil equation was employed to predict the segregation behavior, and the predict results are in consistence with the experimental results. As a result, the confocal scanning laser microscope shows a great potential for solidification process research.

Obsevation for Epidermal Ultrastructure of Nostoc sphaeroides Kutzing under Scanning Electron Microscope

[Objective]The experiment aimed to explore a new way for observing surface structure of Nostoc sphaeroides Kutzing. [Method] The scanning electron microscope was used to observe the epidermal ultrastructure of wild and cultured Nostoc sphaeroides Kutzing. [ Result] The epidermis of wild and cultured Nostoc sphaeroides Kutzing showed mixture structure of fibril colloid which was reticular arranged. The difference between wild and cultured Nostoc sphaeroides Kutzing was that the outer epidermis of cultured Nostoc sphaeroides Kutzing had trichome distribution but the wild Nostoc sphaeroides Kutzing did not has such distribution. The obsevation results of under smaller than 10 μm by scanning electron microscope was touched thick and showed many folds and distortions. [ Conclusion] The scanning electron microscope was an effective way to study development of Nostoc sphaeroides Kutzing colony and it was worth popularizing.

Observation of Helicotylenchus digonicus by Scanning Electron Microscope

[ Objective] The paper was to observe Helicotylenchus digonicus by scanning electron microscope （SEM）. [ Method ] H. digonicus collected from Changxing of Zhejiang Province was observed under scanning electron microscope, and its morphological structure was confmned under optical microscope. [ Resuit]The nematode specimens fixed by glutaraldehyde and osmium tetroxide and prepared by critical point drying were unmodified and unshrinkable with clear mor- phological structure, which could be scanned very well by scanning electron microscope. [ Conclusion ] The study provided reference for study and control of H. digonicus.

Multi-mode Scanning Near-field Optical Microscope

A scanning near-field optical microscope using uncoated fiber tipis described, which can work in transmission and reflectionconfigurations, both capable of working in illumination andcollection-mode, so that either transparent of opaque sample can beinvestigated. Depending on different applications, eitherconstant-gap or constant-height images can be achieved. A compacthomemade translator permits to elect interested area of sample in therange of 4 mm×4 mm.

A Highly Stable Electrochemical Scanning Tunneling Microscope

We demonstrate a home-built electrochemical scanning tunneling microscope （ECSTM）. The ECSTM exhibits highly stable performance. The drifting rates in XY and Z directions of the ECSTM are about 67 and 55.6 pm/min, respectively. Moreover, a specially designed scanner unit successfully solves the well-known problem of large leakage current in high humidity atmosphere. The mechanical structure of the ECSTM is described in detail. The excellent performances of the system are demonstrated by the measured STM images （in copper sulfate solution）, including clean and well-ordered large area morphology of Au（111） and the atomically resolved image of highly oriented pyrolytic graphite.

Compact Scanning Tunneling Microscope with Large Scale Searching Capability for Mmultidisciplinary Applications

We present the design and performance of a home-built scanning tunneling microscope （STM）, which is compact （66 mm tall and 25 mm in diameter）, yet equipped with a 3D atomic precision piezoelectric motor in which the Z coarse approach relies on a high simplic-ity friction-type walker （of our own invention） driven by an axially cut piezoelectric tube. The walker is vertically inserted in a piezoelectric scanner tube （PST） with its brim laying at on the PST end as the inertial slider （driven by the PST） for the XZ （sample plane） motion. The STM is designed to be capable of searching rare microscopic targets （defects, dopants, boundaries, nano-devices, etc.） in a macroscopic sample area （square millimeters） under extreme conditions （low temperatures, strong magnetic elds, etc.） in which it ts. It gives good atomic resolution images after scanning a highly oriented pyrolytic graphite sample in air at room temperature.

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 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.

A Simple,Compact and Rigid Scanning Tunneling Microscope

We present a homebuilt scanning tunneling microscope(STM)which employs an inner-wall polished sapphire guiding tube as a rail for the scanner to form a short tip-sample mechanical loop.The scanner is mounted on a square rod which is housed in the guiding tube and held by a spring strip.The stiff sapphire guiding tube allows the STM body to be made in a simple,compact and rigid form.Also the material of sapphire improves the thermal stability of the STM for its good thermal conductivity.To demonstrate the performance of the STM,high quality atomic-resolution STM images of high oriented pyrolytic graphite were given.

Retrieving analog images from a scanning electron microscopewith a synchronous data acquisition method

In this work,an old scanning electron microscope(SEM)is refurbished to enhance its image processing capability.How to digitally sample and process an analog image is also presented.An NI PCI-6259 multiple input/output data acquisition(DAQ)board is used to acquire signals originally being sent to an analog display,and then convert the signals into a digital image.Two output channels are used for raster scan of the horizontal and verticle axes of the image buffer,while one input channel is used to read the brightness signals at various coordinate points.Synchronous method is used to maximize the DAQ speed.Finally,the digitally buffered images are read out to display and saved in a hard drive.The hardware and software designs of this work are explained in great detail,which can serve as a very good example for fast synchronous DAQ,advanced virtual instrument design and structural driver programming with LabVIEW.

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.

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.

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.

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）.

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.

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

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.

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.