Efficient Identification of the MYC Regulator with the Use of the CRISPR Library and Context-Matched Database Screenings

MYC is a major oncogene that plays an important role in cell proliferation in human cancers. Therefore, the mechanism behind MYC regulation is a viable therapeutic target for the treatment of cancer. Comprehensive and efficient screening of MYC regulators is needed, and we had previously established a promoter screening system using fluorescent proteins and the CRISPR library. For the efficient identification of candidate genes, a database was used, for which mRNA expression was correlated with MYC using datasets featuring “Similar” and “Not exactly similar” contexts. INTS14 and ERI2 were identified using datasets featuring the “Similar” context group, and INTS14 and ERI2 were capable of enhancing MYC promoter activity. In further database analysis of human cancers, a higher expression of MYC mRNA was observed in the INTS14 mRNA high-expressing prostate and liver cancers. The knockdown of INTS14 in prostate cell lines resulted in decreased MYC mRNA and protein expression and also induced G0/1 arrest. This study confirmed that CRISPR screening combined with context-matched database screening is effective in identifying genes that regulate the MYC promoter. This method can be applied to other genes and is expected to be useful in identifying the regulators of other proto-oncogenes.     

Dynamic contrast-enhanced MR imaging of the entire breast with spectral-selective inversion fast three dimensional sequence

Dynamic contrast-enhanced images with high spatial and temporal resolutions were acquired with a fast 3D spoiled gradient echo (SPGR) sequence using spectral selective inversion recovery (IR) pulse. Five healthy volunteers and 12 patients with 14 pathologically proven breast lesions were studied. Fat suppressed volume image data covering the entire breast were obtained with a sufficient spatial resolution (0.9×1.5×3.0 mm³) and an imaging time of 57 s. By using the criteria including peripheral enhancement and presence of spiculation, sensitivity, specificity, and accuracy in detecting malignant lesions were 88.9, 80.0 and 85.%, respectively. Although the C/N and S/N ratios were approximately 30% less than those of the conventional fat suppressed 3D technique, fast 3D SPGR imaging with spectral IR method demonstrated sufficient image quality for both time intensity analysis and morphological evaluation of the breast lesions with a data acquisition time less than half of the conventional method. This technique can substantially improve spatial and temporal resolutions of dynamic MR images of the breast and will be useful in evaluating malignant and benign breast lesions.     

Performance of single‐ and double‐effect operable mechanical vapor recompression desalination system adaptable to variable wind energy

This paper deals with the development and operation of a mechanical vapor recompression (MVR) desalination system with improved energy efficiency in harnessing wind energy, which is non‐dispatchable. Its design, construction, and operation details are presented in this paper. Especially, the main focus of developing the system was on the operation of the system in conjunction with variable loads of new and renewable power sources, in particular, varying wind power. That is, the present work has been carried out to assess the feasibility of its operation in light of capacity modulation to match the power generated under various wind speeds. Optimal operation modes of the system were studied, in which single‐ and double‐effect operations were analyzed for their improvement in energy efficiency. The compression ratio of the proposed MVR system was 1.55 at an inverter speed of 55 Hz, which agreed well with its design value. Operation of the main heat exchanger remained stable within the limits of its operable range, although the temperature differences in the main heat exchanger did not remain constant because of the pressure variations in the evaporator. The daily freshwater yield was between 28 and 51 tons. The power consumption per ton of freshwater produced was about 43 kW for a single effect and about 23 kW for a double effect, which is about twice as efficient.     

Tangential stress range-compressive stress range diagram for fretting fatigue design curve

Fretting fatigue strength can be effectively predicted regardless of pad geometry, rigidity, contact pressure and slip amplitude based on the tangential stress range-compressive stress range diagram. However, the tangential stress range-compressive stress range diagram is a material property and applicable only to the material concerned. In the present study, a new approach for predicting fretting fatigue strength irrespective of material has been proposed based on a generalized tangential stress range-compressive stress range diagram. The generalized tangential stress range-compressive stress range diagram was obtained by normalizing the tangential stress range and compressive stress range values by tensile strength of each material. It was found that the generalized tangential stress range-compressive stress range diagrams for all the steels merged to one line and could be applicable for predicting fretting fatigue strength of wide range of steels.     

Transient Crack Growth Behavior Under Cycle/Time-Dependent Step Loading for Pb-Containing and Pb-Free Solders

In the present study, fatigue crack growth tests of Pb-containing [Sn-37Pb (wt.%)] and Pb-free [Sn-3.0Ag-0.5Cu (wt.%)] solders were performed under cycle/time-dependent step loading at a constant J-integral range (ΔJ). The C ^* parameter was also estimated for discussing time-dependent crack growth behavior. The experimental results indicated that acceleration of the crack growth rate at the beginning of the second loading step was induced when the C ^* value for the first loading step was high, regardless of time- or cycle-dependent crack growth and for both Sn-37Pb and Sn-3.0Ag-0.5Cu solders. The length of the acceleration region of the crack growth rate for both solders was in good agreement with the creep damage zone size estimated by the creep zone model proposed by Riedel and Rice.     

Large Closed-Circuit Seebeck Current in Quaternary (Ti,Zr)NiSn Heusler Alloys

In the (Ti _x ,Zr _y )Ni _w Sn _z quaternary system with a composition near (x + y):w:z = 1:1:1 the existence of the half-Heusler (HH) phase has been confirmed, where Ti and Zr occupy one of the three lattice positions substitutionally. The goal of this study is to characterize the thermoelectric (TE) properties of such materials. TE properties were measured at large temperature differences up to ΔT = 800 K, exhibiting Seebeck voltages of about ±50 mV corresponding to Seebeck coefficients above 0.07 mV/K, with the highest value measured for the (Ti_0.4Zr_0.6)Ni_0.9Sn_1.1 composition. Fe and Mn doping could not improve these values further. Measurements under closed-circuit conditions showed very high currents of 0.4 mA for specimens at this particular composition. According to the composition, interfaces between full-Heusler and HH phases are responsible for an electron pull-out phenomenon due to the electric field at their interfaces. First-principle calculations of the electronic band structure confirm this explanation for why (TiZr)NiSn and CrNiSn are p-type TEs whereas NbNiSn is an n-type TE. These considerations will be useful in the search for other such systems.     

Physical properties and tactile sensory perception of microtextured molded plastics

We developed molded plastic samples with microscale textured features, and investigated the relationship between the tactile sensory response and the physical properties of the surfaces. Samples with various pitch features, and features with various height protrusions were prepared. Changes in the tactile sensory perception of the surfaces were correlated with the magnitude of the fluctuation in the coefficients of friction that occurred as a fingerprint moved across the surface, caused by the intrusion of the features of the textured surface into the grooves of the fingerprint. This occurred when the pitch of the features on the textured surface approached that of the pattern of the fingerprint; the height of the features was not significant. A change in the tactile perception of the surfaces occurred when the pitch of the features at the surface was approximately 100 μm.     

Development of an Evaluation Methodology for Fuel Discharge in Core Disruptive Accidents of Sodium-Cooled Fast Reactors

The purpose of the present study is to develop a methodology to evaluate fuel discharge through the CRGT （control-rod guide tube） during CDAs （core-disruptive accidents） of SFRs （sodium-cooled fast reactors）, since fuel discharge will decrease the core reactivity and CRGTs have a potential to provide an effective discharge path. Fuel discharge contains multi-component fluid dynamics with phase changes, and, in the present study, the SFR safety analysis code SIMMER （Sn, implicit, multifield, multicomponent, Eulerian recriticality） was utilized as a technical basis. First, dominant phenomena affecting fuel discharge through the CRGT are identified based on parametric calculations by the SIMMER code. Next, validations on the code models closely relating to these phenomena were carried out based on experimental data. It was shown that the SIMMER code with some model modifications could reproduce the experimental results appropriately. Through the present study, the evaluation methodology for the molten-fuel discharge through the CRGT was successfully developed.     

Effect of sedimentary facies and geological properties on thermal conductivity of Pleistocene volcanic sediments in Tokyo,central Japan

When ground source heat pump systems are installed underground, an estimate of the thermal conductivity is required to determine the desired total length of the heat exchanger (U-tube). Many large cities in Asia are built on Quaternary sediments, but the thermal conductivity of these sediments is not well understood. To measure the thermal conductivity of Pleistocene volcanic sediments in Tokyo, Japan, we discuss methods of measuring thermal conductivity and factors influencing the thermal conductivity of volcanic sediment, which has low quartz content. The results obtained from experiments using a drill core, borehole data and artificial sediment samples are as follows: (1) values of thermal conductivity predicted using water content, porosity or sand content can be underestimated in volcanic sediment or sediments with large amounts of magnetic minerals; (2) magnetic minerals have a higher thermal conductivity than quartz, so there is a relationship between magnetic susceptibility and thermal conductivity: (3) comparison of thermal conductivity measurements performed using box- and needle-type probes showed that the values measured using the former are comparatively larger. This decrease in thermal conductivity is explained by formation of air-filled cracks when the needle penetrates the sediment, as air has a lower thermal conductivity than sediment.