Advanced neutron irradiation system using Texas A&M University Nuclear Science Center Reactor

A heavily filtered fast neutron irradiation system (FNIS) was developed for a variety of applications, including the study of long-term health effects of fast neutrons by evaluating the biological mechanisms of damage in cultured cells and living animals such as rats or mice. This irradiation system includes an exposure cave made with a lead-bismuth alloy, a cave positioning system, a gamma and neutron monitoring system, a sample transfer system, and interchangeable filters. This system was installed in the irradiation cell of the Texas A&M University Nuclear Science Center Reactor (NSCR). By increasing the thickness of the lead-bismuth alloy, the neutron spectra were shifted into lower energies by the scattering interactions of fast neutrons with the alloy. It is possible, therefore, by changing the alloy thickness, to produce distinctly different dose weighted neutron spectra inside the exposure cave of the FNIS. The calculated neutron spectra showed close agreement with the results of activation foil measurements, unfolded by SAND-II close to the cell window. However, there was a considerable less agreement for locations far away from the cell window. Even though the magnitude of values such as neutron flux and tissue kerma rates in air differed, the weighted average neutron energies showed close agreement between the MCNP and SAND-II since the normalized neutron spectra were in a good agreement each other. A paired ion chamber system was constructed, one with a tissue equivalent plastic (A-150) and propane gas for total dose monitoring, and another with graphite and argon for photon dose monitoring. Using the pair of detectors, the neutron to gamma ratio can be inferred. With the 20 cm-thick FNIS, the absorbed dose rates of neutrons measured with the paired ion chamber method and calculated with the SAND-II results were 13.7 ?? 0.02 Gy/min and 15.5 Gy/min, respectively. The absorbed dose rate of photons and the gamma contribution to total dose were 6.7??10-1 ?? 1.3??10-1 Gy/min and 4.7%, respectively. However, the estimated gamma contribution to total dose varied between 3.6 % to 6.6 % as the assumed neutron sensitivity to the graphite detector was changed from 0.01 to 0.03

The Use of Pluripotent Stem Cell for Personalized Cell Therapies against Neurological Disorders

Although there are a number of weaknesses for clinical use, pluripotent stem cells are valuable sources for patient-specific cell therapies against various diseases. Backed-up by a huge number of basic researches, neuronal differentiation mechanism is well established and pluripotent stem cell therapies against neurological disorders are getting closer to clinical application. However, there are increasing needs for standardization of the sourcing pluripotent stem cells by establishing stem cell registries and banking. Global harmonization will accelerate practical use of personalized therapies using pluripotent stem cells

Purification and characterization of microbial protease produced extracellularly from Bacillus subtilis FBL-1

An ammonium sulfate precipitation of fermentation broth produced by Bacillus subtilis FBL-1 resulted in 2.9-fold increase of specific protease activity. An eluted protein fraction from the column chromatographies using DEAE-Cellulose and Sephadex G-75 had 94.2- and 94.9-fold higher specific protease activity, respectively. An SDS-PAGE revealed a band of purified protease at approximately 37.6 kDa. Although purified protease showed the highest activity at 45°C and pH 9.0, the activity remained stable in temperature range from 30 to 50°C and pH range from 7.0 to 9.0. Protease activity was activated by metal ions such as Ca2+, Mg2+, Mn2+, Fe2+, Ca2+ and K+, but 10 mM Fe3+ significantly inhibited enzyme activity (53%). Protease activity was inhibited by 2 mM EDTA as a metalloprotease inhibitor, but it showed good stability against surfactants and organic solvents. The preferred substrates for protease activity were found to be casein (100%) and soybean flour (71.6%)

Current Researches on the Methods of Diagnosing Sasang Constitution: An Overview

Sasang constitution diagnosis has traditionally been conducted by a Sasang constitutional medicine (SCM) doctor who examines the external appearance, temperament and various symptoms of an individual and then collectively analyzes this information to determine their own constitutions. However, because this process is subjective and not quantitative, many researchers have been attempting to develop objective and reasonable methods of determining constitutions. In Korea, even though a wide range of research regarding SCM has been conducted, most of the work has not been revealed internationally. So in this review, the authors have searched the Journal of Sasang Constitutional Medicine, as well as other Korean domestic journal databases and Pubmed for research regarding modernized constitution diagnosis methods so to provide the understanding of current research state and outlook for future research

Primary Synovial Sarcoma of the Thyroid Gland

Synovial sarcoma is a rare but distinct soft tissue neoplasm, most commonly occurring in para-articular regions of the extremities of young adults and also occurring in the head and neck region. To the best of our knowledge, only one case of primary synovial sarcoma of the thyroid has been previously reported. Here, we report a 15-yr-old man who had a chief complaint of a palpable neck mass. The neck computed tomography revealed a relatively well-demarcated solid mass in the left thyroid gland. After fine needle aspiration cytology, total thyroidectomy and lymph node dissection were performed. Grossly, the mass was covered by the same capsule as the thyroid gland, measuring 6×5×5 cm in dimensions and weighing 78 gm. The cut surface showed a well demarcated, lobulated, grayish tan, and rubbery solid tumor. Histologically, this tumor was a biphasic synovial sarcoma. Immunohistochemical, ultrastructural, genetic studies, and cytologic findings were all consistent with synovial sarcoma. When synovial sarcomas arise in this unusual site, recognition and differential diagnosis become more difficult. The differential diagnosis of a spindle epithelial tumor with thymus-like differentiation is very difficult due to their similar clinical, histological, and immunohistochemical features. Ultrastructural and cytogenetic studies for synovial sarcoma are necessary to establish a definitive diagnosis

Dosimetric Selection for Helical Tomotherapy Based Stereotactic Ablative Radiotherapy for Early-Stage Non-Small Cell Lung Cancer or Lung Metastases

Background No selection criteria for helical tomotherapy (HT) based stereotactic ablative radiotherapy (SABR) to treat early stage non-small cell lung cancer (NSCLC) or solitary lung metastases has been established. In this study, we investigate the dosimetric selection criteria for HT based SABR delivering 70 Gy in 10 fractions to avoid severe toxicity in the treatment of centrally located lesions when adequate target dose coverage is desired. Materials and Methods 78 HT-SABR plans for solitary lung lesions were created to prescribe 70 Gy in 10 fractions to the planning target volume (PTV). The PTV was set to have ≥95% PTV receiving 70 Gy in each case. The cases for which dose constraints for ≥1 OAR could not be met without compromising the target dose coverage were compared with cases for which all target and OAR dose constraints were met. Results There were 23 central lesions for which OAR dose constraints could not be met without compromising PTV dose coverage. Comparing to cases for which optimal HT-based SABR plans were generated, they were associated with larger tumor size (5.72±1.96 cm vs. 3.74±1.49 cm, p\u3c0.0001), higher lung dose, increased number of immediately adjacent OARs ( 3.45±1.34 vs. 1.66±0.81, p\u3c0.0001), and shorter distance to the closest OARs (GTV: 0.26±0.22 cm vs. 0.88±0.54 cm, p\u3c0.0001; PTV 0.19±0.18 cm vs. 0.48±0.36 cm, p = 0.0001). Conclusion Delivery of 70 Gy in 10 fractions with HT to meet all the given OAR and PTV dose constraints are most likely when the following parameters are met: lung lesions ≤3.78 cm (11.98 cc), ≤2 immediately adjacent OARs which are ≥0.45 cm from the gross lesion and ≥0.21 cm from the PTV

Application of Helical Tomotherapy for Two Cases of Advanced Hepatocellular Carcinoma

The role of radiotherapy in the treatment of hepatocellular carcinoma (HCC) has been limited to date, because the liver has a low tolerance to radiation. However, reconstructing tumors and surrounding organs via a three-dimensional conformal planning system can avoid excess radiotherapy exposure to the rest of the liver and adjacent organs. Recently, the concept of "adaptive radiotherapy," such as with helical tomotherapy, has been introduced for treating HCC. Helical tomotherapy obtains an image from the computed tomography component, which allows targeted regions to be visualized prior to, during, and immediately after each treatment and delivers intensity-modulated radiation therapy. We report two patients with advanced HCC who underwent tomotherapy treatment. One was a patient afflicted with advanced HCC and a portal vein tumor thrombus, which was treated with tomotherapy combined with transarterial chemolipiodolization. The other was a patient afflicted with multiple pulmonary metastases treated with tomotherapy followed by systemic chemotherapy

Photo-patternable and transparent films using cellulose nanofibers for stretchable origami electronics

Substantial progress in flexible or stretchable electronics over the past decade has extensively impacted various technologies such as wearable devices, displays and automotive electronics for smart cars. An important challenge is the reliability of these deformable devices under thermal stress. Different coefficients of thermal expansion (CTE) between plastic substrates and the device components, which include multiple inorganic layers of metals or ceramics, induce thermal stress in the devices during fabrication processes or long-term operations with repetitions of thermal cyclic loading-unloading, leading to device failure and reliability degradation. Here, we report an unconventional approach to form photo-patternable, transparent cellulose nanofiber (CNF) hybrid films as flexible and stretchable substrates to improve device reliability using simultaneous electrospinning and spraying. The electrospun polymeric backbones and sprayed CNF fillers enable the resulting hybrid structure to be photolithographically patternable as a negative photoresist and thermally and mechanically stable, presenting outstanding optical transparency and low CTE. We also formed stretchable origami substrates using the CNF hybrid that are composed of rigid support fixtures and elastomeric joints, exploiting the photo-patternability. A demonstration of transparent organic light-emitting diodes and touchscreen panels on the hybrid film suggests its potential for use in next-generation electronics.ope