Search

A study was conducted to analyze the deposition of perpendicular magnetic recording Co-Cr layers with nanosize domains utilizing a plasma improved type of sputtering equipment. The specimen films were deposited on polyimide sheets and glass disks by sputtering Co76Cr24 targets. Experimental results indicated that the ferromagnetic lower C(sub Cr) areas of 3 nm in diameter were formed to be spatially separated by paramagnetic higher C(sub Cr) areas in the surface region of the 50-nm-thick films.

Acquisition of pluripotency by somatic cells is a striking process that enables multicellular organisms to regenerate organs. This process includes silencing of genes to erase original tissue memory and priming of additional cell type specification genes, which are then poised for activation by external signal inputs. Here, through analysis of genome-wide histone modifications and gene expression profiles, we show that a gene priming mechanism involving LYSINE-SPECIFIC DEMETHYLASE 1-LIKE 3 (LDL3) specifically eliminates H3K4me2 during formation of the intermediate pluripotent cell mass known as callus derived from Arabidopsis root cells. While LDL3-mediated H3K4me2 removal does not immediately affect gene expression, it does facilitate the later activation of genes that act to form shoot progenitors when external cues lead to shoot induction. These results give insights into the role of H3K4 methylation in plants, and into the primed state that provides plant cells with high regenerative competency.

Plants have a remarkable regenerative capacity, but it varies widely among species and tissue types. Whether plant cells/tissues initiate regeneration largely depends on the extent to which they are constrained to their original tissue fate. Once cells start the regeneration program, they acquire a new fate, form meristems, and develop into organs. During these processes, the cells must continuously overcome various barriers to the progression of the regeneration program until the organ (or whole plant) is complete. Recent studies have revealed key factors and signals affecting cell fate during plant regeneration. Here, we review recent research on: (i) environmental signal inputs and physical stimuli that act as initial triggers of regeneration; (ii) epigenetic and transcriptional cellular responses to those triggers leading to cellular reprograming; and (iii) molecules that direct the formation and development of the new stem cell niche. We also discuss differences and similarities between regeneration and normal development., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Somatic embryogenesis is one of the best examples of the remarkable developmental plasticity of plants, in which committed somatic cells can dedifferentiate and acquire the ability to form an embryo and regenerate an entire plant. In Arabidopsis thaliana, the shoot apices of young seedlings have been reported as an alternative tissue source for somatic embryos (SEs) besides the widely studied zygotic embryos taken from siliques. Although SE induction from shoots demonstrates the plasticity of plants more clearly than the embryo-to-embryo induction system, the underlying developmental and molecular mechanisms involved are unknown. Here we characterized SE formation from shoot apex explants by establishing a system for time-lapse observation of explants during SE induction. We also established a method to distinguish SE-forming and non-SE-forming explants prior to anatomical SE formation, enabling us to identify distinct transcriptome profiles of these two explants at SE initiation. We show that embryonic fate commitment takes place at day 3 of SE induction and the SE arises directly, not through callus formation, from the base of leaf primordia just beside the shoot apical meristem (SAM), where auxin accumulates and shoot-root polarity is formed. The expression domain of a couple of key developmental genes for the SAM transiently expands at this stage. Our data demonstrate that SE-forming and non-SE-forming explants share mostly the same transcripts except for a limited number of embryonic genes and root genes that might trigger the SE-initiation program. Thus, SE-forming explants possess a mixed identity (SAM, root and embryo) at the time of SE specification., (Copyright © 2018. Published by Elsevier Inc.)

A 54-year-old man had received low anterior resection for rectal carcinoma and extended right hepatectomy for a metastatic liver tumor. One year later, imaging studies disclosed a metastatic liver tumor in segment 2 of the liver. The residual left hepatic vein was completely invaded by the tumor from the root of the hepatic vein to the confluence of several branches by intraoperative ultrasonography. To resect partial liver with the involved hepatic vein was deemed impossible. Microwave coagulation therapy was performed on the tumor and the involved hepatic vein, as we had established the safety of microwave irradiation to the main hepatic vein without interference of the hepatic venous flow in an experimental study. The patient remains well 40 months after the surgery without recurrent signs. The hepatic venous flow of the irradiated hepatic vein is maintained well according to serial examination of Doppler ultrasonography.

A 72-year-old man was referred with an endoscopic diagnosis of Borrmann 2 type advanced gastric cancer. Further examination revealed tumor thrombus in the splenic vein and high serum level of alpha-fetoprotein without liver disease. Intraoperative ultrasonography revealed that tumor thrombus originated from gastric cancer extended to the splenic vein through the left gastric vein. Total gastrectomy combined with distal pancreatectomy and splenectomy was done to obtain complete resection of cancer and tumor thrombus. Tumor and its thrombus in the splenic vein were diagnosed as a poorly differentiated adenocarcinoma that produced alpha-fetoprotein. We report the case, and discuss about the gastric cancer with portal tumor thrombus and high serum levels of alpha-fetoprotein.

The Advanced Earth Observation Satellite (ADEOS), launched in the summer of 1996, has a high-resolution infrared Fourier transform spectrometer, with the interferometric monitor for greenhouse gases (IMG) onboard. The IMG has a high spectral resolution of 0.1 cm(-1) for the purpose of retrieving greenhouse gas profile maps of the Earth. To meet the requirements of the retrieval algorithms for greenhouse gas profiles, atmospheric emission spectra must be calibrated to better than 1 K accuracy. Prior to the launch of the ADEOS with the IMG, we developed an airborne simulator called the tropospheric infrared interferometric sounder (TIIS). We explain the calibration procedure for the TIIS, which determines the points with the same optical path difference on interferograms for complex Fourier transformation, using the retained phase term on the calibrated spectrum. The downward atmospheric radiation, measured with the TIIS, was well calibrated using this algorithm. Furthermore, calibration of the spectra obtained from the IMG initial checkout mission observation was carried out.