High Sensitivity Sensors Made of Perforated Waveguides

Sensors based on surface plasmons or waveguide modes are at the focus of interest for applications in biological or environmental chemistry. Waveguide-mode spectra of 1 μm-thick pure and perforated silica films comprising isolated nanometric holes with great aspect ratio were measured before and after adhesion of streptavidin at concentrations of 500 nM. The shift of the angular position for guided modes was nine times higher in perforated films than in bulk films. Capturing of streptavidin in the nanoholes is at the origin of that largely enhanced shift in the angular position as the amplitude of the guided mode in the waveguide perfectly overlaps with the perturbation caused by the molecules. Hence, the device allows for strongly confined modes and their strong perturbation to enable ultra-sensitive sensor applications

Acetylcholinesterase Secretion by Brugia pahangi in vitro

The experiment was designed to demonstrate acetylcholinesterase (AChE) secretion by Brugia pahangi in vitro. Seventy five B. pahangi adult female worms were cultured in 2 ml of Eagle\u27s minimal essential medium (MEM), and the culture fluid was measured for AChE activity by the colorimetric method of Ellman et al. (1961). The enzymic activity increased by the incubation time during the first 24 hours of culture. In an experiment where 25-150 female worms were cultured for 24 hours, higher enzymic activity was detected in the culture fluid where the larger number of worms were cultured. Since AChE activity was not detected in the culture fluid where 100,000 microfilariae were cultured, the results showed that the AChE was secreted by B. pahangi adult female worms. The adult male worms did not have enzyme secreting potential. The secreted AChE was identified as a single protein by disc electrophoresis and possessed the characteristics of the true AChE for its substrate specificity and inhibition by eserine

Major Causes of Death among Older Adults after the Great East Japan Earthquake : A Retrospective Study

This retrospective study investigated the 3-year impact of the Great East Japan Earthquake (GEJE) of 2011 on deaths due to neoplasm, heart disease, stroke, pneumonia, and senility among older adults in the primarily affected prefectures compared with other prefectures, previous investigations having been more limited as regards mortality causes and geographic areas. Using death certificates issued between 2006 and 2015 (n = 7,383,253), mortality rates (MRs) and risk ratios (RRs) were calculated using a linear mixed model with the log-transformed MR as the response variable. The model included interactions between the area category and each year of death from 2010 to 2013. The RRs in the interaction significantly increased to 1.13, 1.17, and 1.28 for deaths due to stroke, pneumonia, and senility, respectively, in Miyagi Prefecture in 2011, but did not significantly increase for any of the other areas affected by the GEJE. Moreover, increased RRs were not reported for any of the other years. The risk of death increased in 2011; however, this was only significant for single-year impact. In 2013, decreased RRs of pneumonia in the Miyagi and Iwate prefectures and of senility in Fukushima Prefecture were observed. Overall, we did not find evidence of strong associations between the GEJE and mortality

Elongation of gold nanoparticles in silica glass by irradiation with swift heavy ions

We examined the mechanism whereby nanoparticles of gold embedded in silica become elongated and oriented parallel to each other on ion irradiation. Elongation occurred for gold particles with radii smaller than 25 nm. The process was simulated by using a thermal spike model. For small-radius nanoparticles, ion irradiation raises the temperature above the melting points of both gold and silica, whereas for larger nanoparticles neither the gold nanoparticle nor the surrounding silica matrix is melted

The Effect of Praziquantel on Patterns of Schistosoma mansoni Eggshell Hatching Breaks

The break of the eggshell formed by water- and praziquantel (PZQ)-induced hatching of Schistosoma mansoni eggs was observed by scanning electron microscopy. The break most frequently formed on the long axis of the eggshell opposite the spine, and less frequently along spine side, parallel or oblique to the long axis of the lateral side of the egg-shell. An outwardly-curled lip of shell lined the external margins of the hatching orifice. The shell itself was of uniform thickness and fairly smooth. No significant difference was observed in the position breaks between water- and PZQ-hatched eggs. However, PZQ hatching produced smaller hatching orifices and the miracidium frequently failed to escape

Functional Overload Enhances Satellite Cell Properties in Skeletal Muscle

Skeletal muscle represents a plentiful and accessible source of adult stem cells. Skeletal-muscle-derived stem cells, termed satellite cells, play essential roles in postnatal growth, maintenance, repair, and regeneration of skeletal muscle. Although it is well known that the number of satellite cells increases following physical exercise, functional alterations in satellite cells such as proliferative capacity and differentiation efficiency following exercise and their molecular mechanisms remain unclear. Here, we found that functional overload, which is widely used to model resistance exercise, causes skeletal muscle hypertrophy and converts satellite cells from quiescent state to activated state. Our analysis showed that functional overload induces the expression of MyoD in satellite cells and enhances the proliferative capacity and differentiation potential of these cells. The changes in satellite cell properties coincided with the inactivation of Notch signaling and the activation of Wnt signaling and likely involve modulation by transcription factors of the Sox family. These results indicate the effects of resistance exercise on the regulation of satellite cells and provide insight into the molecular mechanism of satellite cell activation following physical exercise

Usefulness of Choline-PET for the detection of residual hemangiopericytoma in the skull base: comparison with FDG-PET

<p>Abstract</p> <p>Background</p> <p>Choline is a new PET tracer that is useful for the detection of malignant tumor. Choline is a precursor of the biosynthesis of phosphatidylcholine, a major phospholipid in the cell membrane of eukaryotic cells. Malignant tumors have an elevated level of phosphatidylcholine in cell membrane. Thus, choline is a marker of tumor malignancy.</p> <p>Method</p> <p>The patient was a 51-year-old man with repeated recurrent hemangiopericytoma in the skull base. We performed Choline-PET in this patient after various treatments and compared findings with those of FDG-PET.</p> <p>Results</p> <p>Choline accumulated in this tumor, but FDG did not accumulate. We diagnosed this tumor as residual hemangiopericytoma and performed the resection of the residual tumor. FDG-PET is not appropriate for skull base tumor detection because uptake in the brain is very strong.</p> <p>Conclusion</p> <p>We emphasize the usefulness of Choline-PET for the detection of residual hemangiopericytoma in the skull base after various treatments, compared with FDG-PET.</p

Microfluidic chips for forward blood typing performed with a multichannel waveguide-mode sensor

We designed a microfluidic chip for use with an evanescent field optical sensor to conduct simultaneous measurements for ABO and Rh(D) forward blood typing. The microfluidic chip was designed to include multiplexed mixers for blood-reagent mixing and chambers for optical measurements. To achieve simple and rapid mixing in the microfluidic channels, holes containing freeze-dried reagents were employed as mixers. In addition, capillary stop valve-based multiplexing of the measurement chambers was used to effectively fill the chambers with samples without empty spaces or leaks. The five-channel microfluidic chip was designed and tested, including the mixing holes and measurement chambers. A multi-channel waveguide-mode sensor was used for optical measurement. Forward blood typing tests using human whole blood samples and anti-A, anti-B, anti-D, and Rh control reagents were conducted on the microfluidic chip. Simultaneous measurements were successfully performed using 40 μL of diluted blood samples, and ABO and Rh(D) blood types could be determined within 5 min. Keywords: Immunoassay, Hemagglutination, Blood typing, Microfluidic channel, Waveguide-mode senso

Waveguide-Mode Sensors as Aptasensors

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