Measurement of human red blood cell deformability using a single micropore on a thin Si3N4 film

The filtration method for the evaluation of the RBC deformability has been further refined to simulate the deformations encountered in the recticuloendothelial system (in particular the spleen), a recognized site of aged and sickled cells removal. The core of the developed measuring system is a very thin (0.4 micron thick) filter that consists of single micropore (diameters down to 1 micron) on a Si3N4 film which has been constructed using silicon microfabrication techniques. Individual RBC's deformability is quantified measuring the cell pore passage time. From one blood sample 200 passage times are analyzed by a computer, displaying mean and median values as deformability indexes, and class and cumulative histograms for studying the passage times distribution. In this paper the effectiveness of the developed system as a routine clinical evaluation tool is demonstrated by studying several factors that are known to affect the RBC deformability, such as temperature, addition of diamide and glutaraldehyde, and blood storage conditions. In addition, it is experimentally demonstrated that the human RBC can traverse a pore with a diameter as small as 1 micron when the pore length is very short, thus broadening the experimental conditions under which the RBC deformability (fluidity) can be studied.     

The weather dependence of particle size distribution of indoor radioactive aerosol associated with radon decay products

This study was performed to measure the activity size distribution of aerosol particles associated with short-lived radon decay products in indoor air at Nagoya University, Nagoya, Japan. The measurements were performed using a low pressure Andersen cascade impactor under variable meteorological conditions. The results showed that the greatest activity fraction was associated with aerosol particles in the accumulation size range (100-1000 nm) with a small fraction of nucleation mode (10-100 nm). Regarding the influence of the weather conditions, the decrease in the number of accumulation particles was observed clearly after rainfall without significant change in nucleation particles, which may be due to a washout process for the large particles.     

The study of activity median aerodynamic diameter using imaging plate technique for assessment of effective dose from radon and its decay products

The indoor workplace environment was evaluated for exposure to radon and its decay products at two Universities in two metropolises of Japan. The mean radon concentrations in Nagoya University (NU) and Hokkaido University (HU) were 16.7 Bq m(-3) and 18.0 Bq m(-3), respectively. Activity median aerodynamic diameter (AMAD) of particles at NU ranged from 172 nm approximately 205 nm and at HU from 186 nm approximately 300 nm. Estimated effective doses for five usual sites of NU by ICRP approach was 0.15 mSvy(-1) approximately 0.76 mSvy(-1) and by UNSCEAR approach was 0.05 mSvy(-1) approximately 0.24 mSvy(-1). The effective dose for the same of HU by ICRP 66 approach was 0.16 mSvy(-1) approximately 0.79 mSvy(-1) and by UNSCEAR 2000 approach was 0.05 mSv y(-1) to 0.26 mSv y(-1). The two approaches differs on an average by a factor 2.3- approximately 4.7. The AMAD of obtained particle size distribution at NU has an average total deposition of 23% in human respiratory tract and 20% at HU.     

Lipopolysaccharide induces manganese superoxide dismutase in the rat pancreas: its role in caerulein pancreatitis

Intraperitoneal injection of lipopolysaccharide (LPS) at a dose of 50 micrograms/kg increased the activity and the mRNA level of manganese superoxide dismutase (Mn-SOD) but did not change those of copper/zinc-SOD (Cu/Zn-SOD) in the rat pancreas. Both the formation of pancreatic edema and the elevation of serum amylase during caerulein pancreatitis were significantly relieved in the rats pretreated with LPS (50 micrograms/kg) compared with the rats without the pretreatment. These results support the view that superoxides play a key role in the pathogenesis of caerulein pancreatitis, and that Mn-SOD in the pancreas may work as a defense against the development of this disease.     

Precise measurement of SAW velocity using SAW delay line

A method of nondestructive evaluation (NDE) by measuring the acoustic properties of materials using a surface-acoustic-wave (SAW) delay line is presented. A SAW delay line with three interdigital transducers (IDTs) deposited on a piezoelectric substrate is used to measure the SAW velocity of the sample material, using a fluid couplant. The SAW velocity is obtained from the frequency dependence of the delay line, and movement in the z-direction is not required. Measurements have been made for an anisotropic material at frequencies from 35 to 55 MHz. The experimental results agree well with the theoretical results. Moreover, it has been found that the focused SAW excited from a Fresnel-phase-plate IDT is suitable for mapping the two-dimensional variation of SAW velocity on an anisotropic sample surface.     

Spatial distributions of atmospheric concentrations of radionuclides on 15 March 2011 discharged by the Fukushima Dai-Ichi Nuclear Power Plant Accident estimated from NaI(Tl) pulse height distributions measured in Ibaraki Prefecture

ABSTRACT

A hybrid method for estimation of atmospheric concentrations of multiple radionuclides was developed and applied to NaI(Tl) pulse height records measured in Ibaraki Prefecture in the morning of 15 March 2011 when three radioactive plumes from the Fukushima Dai-Ichi Nuclear Power Plant Accident passed. The method is based on the simple principle for separation from deposited radionuclides’ contribution and the concentration estimation for multiple radionuclides. Difficulty in the concentration estimation due to complexity of surrounding terrains and geometry was overcome to obtain spatiotemporal variations in atmospheric concentrations of Xe-133, Te-132, I-131, I-132 and I-133 in the three plumes at 21 monitoring stations. The plume axis with higher I-131 concentration of 5.40 kBq m-3 than the previous estimations during the second plume was found in the northwestern inland area. A substantially lower Xe-133/I-131 concentration ratio of the first plume than those of the others was again recognized. The details of non-uniform spatial distribution of the radionuclide composition were found for each of the three plumes.