A new method for the chemical determination of radium in sea water

In a method for the determination of radium in sea water, radium is coprecipitated with calcium carbonate from the sea water and redissolved in dilute hydrochloric acid; it is then isolated by precipitation with barium rhodizonate, followed by separation on an ion exchange column. The radium compound is then dried and ignited on a platinum disk, and its radioactivity is measured with an α-spectrometer. The average recovery of radium from sea water is 94.0 ± 2.0%

Chemical Etching of Silicon Assisted by Graphene Oxide in an HF–HNO₃ Solution and Its Catalytic Mechanism

Chemical etching of silicon assisted by various types of carbon materials is drawing much attention for the fabrication of silicon micro/nanostructures. We developed a method of chemical etching of silicon that utilizes graphene oxide (GO) sheets to promote the etching reaction in a hydrofluoric acid–nitric acid (HF–HNO₃) etchant. By using an optimized composition of the HF–HNO₃ etchant, the etching rate under the GO sheets was 100 times faster than that of our HF–H₂O₂ system used in a previous report. Kinetic analyses showed that the activation energy of the etching reaction was almost the same at both the bare silicon and GO-covered areas. We propose that adsorption sites for the reactant in the GO sheets enhance the reaction frequency, leading to a deeper etching in the GO areas than the bare areas. Furthermore, GO sheets with more defects were found to have higher catalytic activities. This suggests that defects in the GO sheets function as adsorption sites for the reactant, thereby enhancing the etching rate under the sheets

Formation of submicron-sized silica patterns on flexible polymer substrates based on vacuum ultraviolet photooxidation

Formation of precise and high-resolution silica micropatterns on polymer substrates is of importance in surface structuring for flexible device fabrication of optics, microelectronic, and biotechnology. To achieve that, substrates modified with affinity-patterns serve as a strategy for site-selective deposition. In the present paper, vacuum ultraviolet (VUV) treatment is utilized to achieve spatially-controlled surface functionalization on a cyclo-olefin polymer (COP) substrate. An organosilane, 2, 4, 6, 8-tetramethylcyclotetrasiloxane (TMCTS), preferentially deposits on the functionalized regions. Well-defined patterns of TMCTS are formed with a minimum feature of ∼500 nm. The secondary VUV/(O)-treatment converts TMCTS into SiOx, meanwhile etches the bare COP surface, forming patterned SiOx/COP microstructures with an average height of ∼150 nm. The resulting SiOx patterns retain a good copy of TMCTS patterns, which are also consistent with the patterns of photomask used in polymer affinity-patterning. The high quality SiOx patterns are of interests in microdevice fabrication, and the hydrophilicity contrast and adjustable heights reveal their potential application as a “stamp” for microcontact printing (μCP) techniques

Fundamental and higher eigenmodes of qPlus sensors with a long probe for vertical-lateral bimodal atomic force microscopy

The detection of vertical and lateral forces at the nanoscale by atomic force microscopy (AFM) reveals various mechanical properties on surfaces. The qPlus sensor is a widely used force sensor, which is built from a quartz tuning fork (QTF) and a sharpened metal probe, capable of high-resolution imaging in viscous liquids such as lubricant oils. Although a simultaneous detection technique of vertical and lateral forces by using a qPlus sensor is required in the field of nanotribology, it has still been difficult because the torsional oscillations of QTFs cannot be detected. In this paper, we propose a method to simultaneously detect vertical and lateral force components by using a qPlus sensor with a long probe. The first three eigenmodes of the qPlus sensor with a long probe are theoretically studied by solving a set of equations of motion for the QTF prong and probe. The calculation results were in good agreement with the experimental results. It was found that the tip oscillates laterally in the second and third modes. Finally, we performed friction anisotropy measurements on a polymer film by using a bimodal AFM utilizing the qPlus sensor with a long probe to confirm the lateral force detection

Guideline-based Treatment of Glucocorticoid-induced Osteoporosis in Patients with Rheumatoid Arthritis: A Retrospective Study with the AORA Registry

Glucocorticoid-induced osteoporosis (GIOP) is one of the side effects associated with glucocorticoid (GC) therapy. In 2014, the Japanese Society for Bone and Mineral Research (JSBMR) provided new guidelines for the management and treatment of GIOP. The aim of the present study was to clarify the prevalence of patients with rheumatoid arthritis (RA) requiring treatment according to the new guidelines and to identify risk factors associated with lack of treatment in these patients. Patients in the 2018 Akita Orthopedic group on Rheumatoid Arthritis (AORA) database were enrolled. Of 2,234 patients with RA in the database, 683 (30.6%) met the 2014 JSBMR guideline treatment criteria, and 480 (70.3%) had been treated. The untreated group included a larger number of males, younger patients, and patients treated in clinics rather than hospital (p<0.001, p=0.015, and p<0.001, respectively). Multivariate analyses found that male sex, younger age, and clinic-based RA care were significant risk factors associated with lack of treatment (p<0.001, p=0.013, and p<0.001, respectively). Thus, male sex, younger age, and clinic-based care were identified as risk factor

Molecular packing density of a self-assembled monolayer formed from N-(2-aminoethyl)-3-aminopropyltriethoxysilane by a vapor phase process.

The molecular density of an aminosilane self-assembled monolayer formed from N-(2-aminoethyl)-3-aminopropyltriethoxysilane (AEAPS) by a vapor phase method has been estimated to be about 3 AEAPS molecules per nm(2) based on chemical labeling, optical absorption spectroscopy and X-ray photoelectron spectroscopy

Revaluation of equilibrium quotient between titanium ions and metallic titanium in NaCl–KCl equimolar molten salt

In this study, the effect of oxide ion on the equilibrium between titanium ions and metallic titanium was investigated in NaCl–KCl equimolar molten salt. The soluble species containing Ti^[3+] and O^[2−] was not confirmed in the molten salt by absorption spectroscopy. The result of XRD for the solidified sample containing Ti^[3+] and O^[2−] implies that O2− reacts with Ti^[3+] and Cl^− to form TiOCl(s). The concentration quotient of the equilibrium between titanium ions (Ti^[2+], Ti^[3+]) and metallic Ti, Kc, was revaluated at 740℃ as follows:3Ti^[2+]⇄2Ti^[3+]+Ti, Kc=8.0×10^[−2] mol L−1=1.2×10^[−1] mol kg^[−1]. In addition, the solubility product of TiOCl(s) in NaCl–KCl equimolar molten salt, Ksp, at 700℃ was determined using the results of absorption spectra, Ksp=1.2×10^[−2] mol^2 L−2=5.1×10^[−3] mol^2 kg^[−2]

Absence of germline mono-allelic promoter hypermethylation of the CDH1 gene in gastric cancer patients

<p>Abstract</p> <p>Background</p> <p>Germline mono-allelic promoter hypermethylation of the <it>MLH1 </it>or <it>MSH2 </it>gene in families with hereditary nonpolyposis colorectal cancer has recently been reported. The purpose of this study was to evaluate if germline promoter hypermethylation of the tumor suppressor gene <it>CDH1 </it>(<it>E-cadherin</it>) might cause predisposition to gastric cancer.</p> <p>Methods</p> <p>We prepared two groups of samples, a group of blood samples from 22 patients with familial gastric cancer or early-onset gastric cancer selected from among 39 patients, and a group of non-cancerous gastric tissue samples from 18 patients with sporadic gastric cancer showing loss of CDH1 expression selected from among 159 patients. We then investigated the allele-specific methylation status of the <it>CDH1 </it>promoter by bisulfite sequencing of multiple clones.</p> <p>Results</p> <p>Although there was a difference between the methylation level of the two alleles in some samples, there was no mono-allelic promoter hypermethylation in any of the samples.</p> <p>Conclusion</p> <p>These results suggest that germline mono-allelic hypermethylation of the <it>CDH1 </it>promoter is not a major predisposing factor for gastric cancer.</p

The CRKL gene encoding an adaptor protein is amplified, overexpressed, and a possible therapeutic target in gastric cancer

<p>Abstract</p> <p>Background</p> <p>Genomic DNA amplification is a genetic factor involved in cancer, and some oncogenes, such as <it>ERBB2</it>, are highly amplified in gastric cancer. We searched for the possible amplification of other genes in gastric cancer.</p> <p>Methods and Results</p> <p>A genome-wide single nucleotide polymorphism microarray analysis was performed using three cell lines of differentiated gastric cancers, and 22 genes (including <it>ERBB2</it>) in five highly amplified chromosome regions (with a copy number of more than 6) were identified. Particular attention was paid to the <it>CRKL</it> gene, the product of which is an adaptor protein containing Src homology 2 and 3 (SH2/SH3) domains. An extremely high <it>CRKL</it> copy number was confirmed in the MKN74 gastric cancer cell line using fluorescence <it>in situ</it> hybridization (FISH), and a high level of CRKL expression was also observed in the cells. The RNA-interference-mediated knockdown of CRKL in MKN74 disclosed the ability of CRKL to upregulate gastric cell proliferation. An immunohistochemical analysis revealed that CRKL protein was overexpressed in 24.4% (88/360) of the primary gastric cancers that were analyzed. The <it>CRKL</it> copy number was also examined in 360 primary gastric cancers using a FISH analysis, and <it>CRKL</it> amplification was found to be associated with CRKL overexpression. Finally, we showed that MKN74 cells with <it>CRKL</it> amplification were responsive to the dual Src/BCR-ABL kinase inhibitor BMS354825, likely via the inhibition of CRKL phosphorylation, and that the proliferation of MKN74 cells was suppressed by treatment with a CRKL-targeting peptide.</p> <p>Conclusion</p> <p>These results suggested that CRKL protein is overexpressed in a subset of gastric cancers and is associated with <it>CRKL</it> amplification in gastric cancer. Furthermore, our results suggested that CRKL protein has the ability to regulate gastric cell proliferation and has the potential to serve as a molecular therapy target for gastric cancer.</p