External Flow of an Acoustically Levitated Droplet

One of the major recent advances for experiments in containerless processing is acoustic levitation. Although there are a lot of previous studies for acoustic levitation, characteristic of external flow of an acoustically levitated droplet is not experimentally examined enough. In this study, external flow field has been observed by using high speed camera and Particle Image Velocimetry. In the case of any levitated droplet at a velocity antinode of standing wave, toroidal vortex are generated around levitated droplet. It is found that toroidal vortex around a levitated droplet is strongly affected by viscosity of levitated samples and input voltage. In terms of water droplet, as input voltage is decreased, location of toroidal vortex is moved from bottom to top of levitated samples.     

Second-generation maskless photolithography device for surface micropatterning and microfluidic channel fabrication

We have previously reported on a maskless photolithography device for surface micropatterning and microfabrication by modifying a commercially available liquid crystal display projector. For the prototype, 10-microm resolution was achieved by downsizing the image on a 0.7-in. liquid crystal display panel to an area of 8 x 6 mm and projecting it on a fixed stage. Here, we report on a second-generation maskless photolithography device having two novel features. First, the sliding lens system with variable focal distances and exchangeable objective lenses achieves a variable resolution of 2-8 mum. Second, the synchronous control of displayed images generated by a personal computer and the movement of a XY-positioning stage allows for the fabrication of micropatterns over a larger area (over 50 x 50 mm). Here, we show examples fabricated with the two novel features.     

The distribution of T lymphocytes,B lymphocytes,and dendritic‐like cells of the anal tonsil in the laboratory shrew,Suncus murinus

We investigated the distribution of T lymphocytes, B lymphocytes, and S‐100 protein‐immunoreactive dendritic‐like in the anal tonsil of the laboratory shrew, Suncus murinus. In adult animals, T lymphocytes were located mainly at the periphery of the anal tonsil, especially around small blood vessels. B lymphocytes were located in the central and subepithelial region of the anal tonsil, which includes primary lymphoid follicles, and in which there are small numbers of scattered T lymphocytes. B and T lymphocytes were distributed over 72.7 and 27.3% of the tonsillar area, respectively. However, their areas of distribution were not clearly distinguished. The areas containing B lymphocytes were enriched in S‐100 protein antibody‐immunoreactive cells, which exhibited a dendritic shape. These S‐100‐positive cells appeared to be identical to the follicular dendritic cells (FDC) seen in the follicles of lymphoid organs. These results suggest that the anal tonsils constitute one of the gut‐associated lymphoid tissues (GALT), and that a function of the anal tonsil includes the capture of intruding antigens that would generate protective antibody responses. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.     

Single-shot surface profiling by local model fitting

A new surface profiling algorithm called the local model fitting (LMF) method is proposed. LMF is a single-shot method that employs only a single image, so it is fast and robust against vibration. LMF does not require a conventional assumption of smoothness of the target surface in a band-limit sense, but we instead assume that the target surface is locally constant. This enables us to recover sharp edges on the surface. LMF employs only local image data, so objects covered with heterogeneous materials can also be measured. The LMF algorithm is simple to implement and is efficient in computation. Experimental results showed that the proposed LMF method works very well.     

Novel method for estimating viable Salmonella cell counts using real-time PCR

A novel method for estimating viable Salmonella Enteritidis cell counts with 5'-nuclease real-time PCR was developed in this study. Our method was based on the increase kinetics of the target DNA region (invA) of the microorganism growing in a food/clinical sample in a culture medium during incubation. The index of increase in the target DNA region studied here was threshold cycle, CT. A test Salmonella strain was grown in buffered peptone water at the optimal temperature (39 degrees C). As Salmonella cells were grown, the value of CT decreased with time, generating a downward sigmoidal curve. The slope of the curve was constant at various initial cell concentrations. With higher initial cell concentration, the CT value evaluated from the slope at a given time was lower. With this relationship, a novel method for estimating the initial viable cell concentration of a sample was developed. Dead Salmonella cells or bacteria other than the target cell caused deviation in the CT curve. Incubation in a selective media suppressed the deviation caused by other bacterial cells. We think that this method could be applied to many other microorganisms cultivable in a suitable medium.