<Original Article> A Degradative Process Suggestive of Autophagic Death in Post-Senescent Cells of Yeast Observed by Light Microscopy

We previously reported that when virgin temperature-sensitive mutant edc28 cells of the yeast Saccharomyces cerevisiae were incubated at restrictive temperatures, they lost proliferative activity in 24 hr and thereafter cellular components became progressively degraded resulting in extensive fragmentation in 7 days in parallel with morphological changes suggestive of autophagocytosis. The process was named autophagic death. Here, to test whether yeast cells in the post-senescent life span undergo autophagic death, the edc28 cells were incubated at the permissive temperature and the cells that ceased the cell cycle during bud formation were observed by light microscopy for 7 days. Most cells that stopped the cell cycle produced an abnormally large bud. They accumulated vesicles within 24 hr after the arrest of the cell cycle and became shrunken and thin cytoplasm at day 7. A control strain without cdc mutation showed essentially the same morphological changes as the cdc28 senescent cells, suggesting that the biological process suggestive of autophagic death under light microscopy occurred in the post-senescence life span of the cells irrespective of cdc mutations.journal articl

Membrane Topology of the H+-Pyrophosphatase of Streptomycescoelicolor Determined by Cysteine-Scanning Mutagenesis

The H^+-translocating pyrophosphatase (H^+-PPase) is a proton pump that is found in a wide variety of organisms. It consists of a single polypeptide chain that is thought to possess between 14 and 17 transmembrane domains. To determine the topological arrangement of its conserved motifs and transmembrane domains, we carried out a cysteine-scanning analysis by determining the membrane topology of cysteine-substitution mutants of Streptomyces coelicolor H^+-PPase expressed in Escherichia coli, using chemical reagents. First, we prepared a synthetic DNA that encoded the enzyme and constructed a functional cysteine-less mutant by substituting the four cysteine residues. We then introduced cysteine residues individually into 42 sites in its hydrophilic regions, and N- and C-terminal segments. Thirtysix of the mutant enzymes retained both pyrophosphatase and H^+-translocating activities. Analysis of 29 of these mutant forms using membrane permeable and impermeable sulfhydryl reagents revealed that S. coelicolor H^+-PPase contains 17 transmembrane domains, and that several conserved segments, such as the substrate-binding domains, are exposed to the cytoplasm. Four essential serine residues that were located on the cytoplasmic side were also identified. A marked characteristic of the S. coelicolor enzyme is a long additional sequence, which includes a transmembrane domain at the C-terminus. We propose that the basic structure of H^+-PPases has 16 transmembrane domains with several large cytoplasmic loops containing functional motifs.journal articl

A study on photovoltaic power generation

We studied the characteristics of photovoltaic power generation and summarized as follows, 1.Very few ratio of solar power generation(0.4%)in total power generation in Japan. 2. The lowest annual utilization rate of photovoltaic power generation plant ( ～ 12 % ). 3. The beginning of drastic introduction in Japan and the further greater introduction of ~500MW/year. 4. The cost reduction is required for the introduction by large scale production and technology innovation.departmental bulletin pape

Improved measurement of CP-violation parameters sin⁡2ϕ1 and |λ|, B meson lifetimes, and B0-B̅0 mixing parameter Δmd

journal articl

私の体験談

一般雑誌記事 / Articlearticl

Chemical Imaging of Latent Fingerprints by Mass Spectrometry Based on Laser Activated Electron Tunneling

Identification of endogenous and exogenous chemicals contained in latent fingerprints is important for forensic science in order to acquire evidence of criminal identities and contacts with specific chemicals. Mass spectrometry has emerged as a powerful technique for such applications without any derivatization or fluorescent tags. Among these techniques, MALDI (Matrix Assisted Laser Desorption Ionization) provides small beam size but has interferences with MALDI matrix materials, which cause ion suppressions as well as limited spatial resolution resulting from uneven distribution of MALDI matrix crystals with different sizes. LAET (Laser Activated Electron Tunneling) described in this work offers capabilities for chemical imaging through electron-directed soft ionization. A special film of semiconductors has been designed for collection of fingerprints. Nanoparticles of bismuth cobalt zinc oxide were compressed on a conductive metal substrate (Al or Cu sticky tape) under 10 MPa pressure. Resultant uniform thin films provide tight and shining surfaces on which fingers are impressed. Irradiation of ultraviolet laser pulses (355 nm) on the thin film instantly generates photoelectrons that can be captured by adsorbed organic molecules and subsequently cause electron-directed ionization and fragmentation. Imaging of latent fingerprints is achieved by visualization of the spatial distribution of these molecular ions and structural information-rich fragment ions. Atomic electron emission together with finely tuned laser beam size improve spatial resolution. With the LAET technique, imaging analysis not only can identify physical shapes but also reveal endogenous metabolites present in females and males, detect contacts with prohibited substances, and resolve overlapped latent fingerprints

Knowledge and practices of vaccination for children with rheumatic diseases: A single-center study in China

Patients with pediatric rheumatic diseases (PRDs) have higher morbidity and mortality associated with infectious diseases. Vaccination is an effective way to prevent infection. This study aimed to understand the vaccination status, vaccination-related attitudes, and adverse reactions in patients with PRDs in one of the largest Pediatric Rheumatic and Immune centers in China. A cross-sectional study using an online questionnaire was conducted among the caregivers of patients with PRDs admitted to the Children’s Hospital of Chongqing Medical University. 189 valid questionnaires were collected. The most two common PRDs in this study were juvenile idiopathic arthritis (29.6%) and systemic lupus erythematosus (19.6%). Univariate analysis and multivariate logistic regression were used to identify potential factors associated with vaccination completion among these patients. Univariate analysis suggested that the age of onset, course of the disease, treatment duration, disease duration p p = .002) and caregiver concerns about vaccination before illness (OR, 0.600; 95% CI, 0.428–0.840; p = .003) independently influenced patients’ completion of scheduled vaccinations. This study suggests that rheumatic disease and treatment may influence age-appropriate vaccination. Appropriate education for patients and carers may improve vaccination cognition and attitudes.</p

Laser Activated Electron Tunneling Based Mass Spectrometric Imaging of Molecular Architectures of Mouse Brain Revealing Regional Specific Lipids

A comprehensive description of overall brain architecture at the molecular level is essential for understanding behavioral and cognitive processes in health and diseases. Although fluorescent labeling of target proteins has been successfully established to visualize a brain connectome, the molecular basis for diverse neurophysiological phenomena remains largely unknown. Here we report a brain-wide, molecular-level, and microscale imaging of endogenous metabolites, in particular, lipids of mouse brain by using laser activated electron tunneling (LAET) and mass spectrometry. In this approach, atomic electron emission along with finely tuned laser beam size provides high resolution that can be down to the sub-micrometer level to display spatial distribution of lipids in mouse brain slices. Electron-directed soft ionization has been achieved through exothermal capture of tunneling photoelectrons as well as unpaired electron-initiated chemical bond cleavages. Regionally specific lipids including saturated, mono-unsaturated, and poly-unsaturated fatty acids as well as other lipids, which may be implicated in neurological signaling pathways, have been discovered by using this laser activated electron tunneling based mass spectrometric imaging (LAET-MSI) technique

Table_1_Diagnostic value of cerebrospinal fluid human epididymis protein 4 for leptomeningeal metastasis in lung adenocarcinoma.xlsx

BackgroundThe diagnosis of lung adenocarcinoma (LUAD) leptomeningeal metastasis (LM) remains a clinical challenge. Human epididymis protein 4 (HE4) functions as a novel tumor biomarker for cancers. This study aimed to assess the diagnostic value of cerebrospinal fluid (CSF) HE4, and combined with CEACAM6, for LUAD LM.MethodsThe CSF HE4 protein level was measured in two independent cohorts by electrochemiluminescence. Test cohort included 58 LUAD LM patients, 22 LUAD patients without LM (Wiot-LM), and 68 normal controls. Validation cohort enrolled 50 LUAD LM patients and 40 normal controls, in parallel with Wiot-LM patients without brain metastases (19 Wiot-LM/BrM patients) or with BrM (26 BrM patients). The CSF level of CEA, CA125, CA153, CA199, CA724, NSE and ProGRP of these samples was measured by electrochemiluminescence, whereas the CSF CEACAM6 level was detected by enzyme-linked immunosorbent assay (ELISA). In addition, the serum level of these biomarkers was detected by same method as CSF.ResultsThe level of HE4 or CEACAM6 in CSF samples from LUAD LM patients was significantly higher than those from normal controls and Wiot-LM patients. The HE4 or CEACAM6 level in CSF was higher than that in serum of LM patient. The CSF HE4 or CEACAM6 level for distinguished LM from Wiot-LM showed good performance by receiver-operating characteristic analysis. The better discriminative power for LM was achieved when HE4 was combined with CEACAM6. In addition, the CSF HE4 and CEACAM6 level showed little or no difference between Wiot-LM/BrM and BrM patients, the BrM would not significantly influence the HE4 or CEACAM6 level in CSF. The diagnostic power of CSF CA125, CA153, CA199, CA724, NSE and ProGRP for LUAD LM were not ideal.ConclusionThe combination with HE4 and CEACAM6 has the promising application for the diagnosis of LUAD LM.</p

Direct Growth of Hexagonal Boron Nitride Nanofilms on Stainless Steel for Corrosion Protection

Protection of stainless steel from water, oxygen, and chloride ions is of crucial importance for diverse industrial fields; yet, it remains challenging to develop a proper solution with improved corrosion and oxidation resistance for long-term service durability. Here, we demonstrate the direct growth of hexagonal boron nitride (h-BN) nanofilms on the surface of stainless steel (ss304) by the magnetron sputtering method, serving as barrier coatings for protection in a corrosive environment. The obtained h-BN nanofilms are ∼200 nm in thickness, with a highly densified morphology, converting the hydrophilic surface of ss304 to a hydrophobic surface. These films exhibit excellent oxidation resistance at 600 °C in the atmosphere and enhanced anticorrosion performance as compared to the bare ss304. Moreover, they show robust and stable corrosion resistance when immersed in a 3.5 wt % NaCl electrolyte for over 10 weeks. The results suggest that the direct growth of h-BN nanofilms on ss304 holds great promise for corrosion inhibition and antioxidation of steel, therefore offering a feasible and effective route for long-term corrosion protection concerning practical applications of h-BN on industry-relevant surfaces