Emergence of metallic surface states and negative differential conductance in thin β\beta-FeSi2_2 films on Si(001)

The electronic properties of the surface of $\beta$-FeSi$_2$ have been debated for a long while. We studied the surface states of $\beta$-FeSi$_2$ films grown on Si(001) substrates using scanning tunnelling microscopy (STM) and spectroscopy (STS), with the aid of density functional theory (DFT) calculations. STM simulations using the surface model proposed by Romanyuk et al. [Phys. Rev. B 90, 155305 (2014)] reproduce the detailed features of experimental STM images. The result of STS showed metallic surface states in accordance with theoretical predictions. The Fermi level was pinned by a surface state that appeared in the bulk band gap of the $\beta$-FeSi$_2$ film, irrespective of the polarity of the substrate. We also observed negative differential conductance at $\sim$0.45 eV above the Fermi level in STS measurements performed at 4.5 K, reflecting the presence of an energy gap in the unoccupied surface states of $\beta$-FeSi$_2$.Comment: 16 pages, 5 figure

Metal cations modulate the bacteriochlorophyll–protein interaction in the light-harvesting 1 core complex from Thermochromatium tepidum

AbstractThe light-harvesting 1 reaction center (LH1-RC) complex from Thermochromatium (Tch.) tepidum exhibits unusual Qy absorption by LH1 bacteriochlorophyll-a (BChl-a) molecules at 915nm, and the transition energy is finely modulated by the binding of metal cations to the LH1 polypeptides. Here, we demonstrate the metal-dependent interactions between BChl-a and the polypeptides within the intact LH1-RC complexes by near-infrared Raman spectroscopy. The wild-type LH1-RC (B915) exhibited Raman bands for the C3-acetyl and C13-keto CO stretching modes at 1637 and 1675cm−1, respectively. The corresponding bands appeared at 1643 and 1673cm−1 when Ca2+ was biosynthetically replaced with Sr2+ (B888) or at 1647 and 1669cm−1 in the mesophilic counterpart, Allochromatium vinosum. These results indicate the significant difference in the BChl–polypeptide interactions between B915 and B888 and between B915 and the mesophilic counterpart. The removal of the original metal cations from B915 and B888 resulted in marked band shifts of the C3-acetyl/C13-carbonyl νCO modes to ~1645/~1670cm−1, supporting a model in which the metal cations are involved in the fine-tuning of the hydrogen bonding between the BChl-a and LH1-polypeptides. Interestingly, the interaction modes were almost identical between the Ca2+-depleted B915 and Sr2+-depleted B888 and between B915 and Ca2+-substituted B888, despite the significant differences in their LH1 Qy peak positions and the denaturing temperatures, as revealed by differential scanning calorimetry. These results suggest that not only the BChl–polypeptide interactions but some structural origin may be involved in the unusual Qy red-shift and the enhanced thermal stability of the LH1-RC complexes from Tch. tepidum

Bioorganic synthesis of a recombinant HIV-1 fusion inhibitor, SC35EK, with an N-terminal pyroglutamate capping group.

The bioorganic synthesis of an end-capped anti-HIV peptide from a recombinant protein was investigated. Cyanogen bromide-mediated cleavage of two Met-Gln sites across the target anti-HIV sequence generated an HIV-1 fusion inhibitor (SC35EK) analog bearing an N-terminal pyroglutamate (pGlu) residue and a C-terminal homoserine lactone (Hsl) residue. The end-capped peptide, pGlu-SC35EK-Hsl, had similar bioactivity and biophysical properties to the parent peptide, and an improved resistance to peptidase-mediated degradation was observed compared with the non-end-capped peptide obtained using standard recombinant technology

CT-based CTVHR for cervical brachytherapy

Our purpose was to develop recommendations for contouring the computed tomography (CT)-based high-risk clinical target volume (CTVHR) for 3D image-guided brachytherapy (3D-IGBT) for cervical cancer. A 15-member Japanese Radiation Oncology Study Group (JROSG) committee with expertise in gynecological radiation oncology initiated guideline development for CT-based CTVHR (based on a comprehensive literature review as well as clinical experience) in July 2014. Extensive discussions occurred during four face-to-face meetings and frequent email communication until a consensus was reached. The CT-based CTVHR boundaries were defined by each anatomical plane (cranial–caudal, lateral, or anterior–posterior) with or without tumor progression beyond the uterine cervix at diagnosis. Since the availability of magnetic resonance imaging (MRI) with applicator insertion for 3D planning is currently limited, T2-weighted MRI obtained at diagnosis and just before brachytherapy without applicator insertion was used as a reference for accurately estimating the tumor size and topography. Furthermore, utilizing information from clinical examinations performed both at diagnosis and brachytherapy is strongly recommended. In conclusion, these recommendations will serve as a brachytherapy protocol to be used at institutions with limited availability of MRI for 3D treatment planning

A subset of ocular adnexal marginal zone lymphomas may arise in association with IgG4-related disease

We previously suggested a relationship between ocular immunoglobulin (Ig)G4-related disease (IgG4-RD) and marginal zone lymphomas (MZLs). However, the cytokine background associated with these disorders and whether it differs between ocular adnexal MZLs with (IgG4-associated MZL) and without (IgG4-negative MZL) numerous IgG4+ plasma cells are unknown. In this study, we identified the mRNA expression pattern of Th2 and regulatory T-cell (Treg) cytokines in IgG4-RD and in IgG4-associated MZL and IgG4-negative MZL using real-time polymerase chain reaction analysis. Ocular IgG4-RD and IgG4-associated MZL exhibited significantly higher expression ratios of interleukin (IL)-4/β-actin, IL-10/β-actin, IL-13/β-actin, transforming growth factor (TGF) β1/β-actin, and FOXP3/β-actin than did IgG4-negative MZL (p < 0.05). This finding further supports our prior observations that a significant subset of ocular MZLs arises in the setting of IgG4-RD. Furthermore, the presence of a different inflammatory background in IgG4-negative MZLs suggests that IgG4-associated MZLs may have a different pathogenesis

Significance of measurement of tumor marker in primary breast cancer

We investigated a prognosis in the presence or absence of preoperative marker abnormality for 371 cases with primary breast cancer that we experienced in our department this time. 60 (16%) of 371 cases showed the abnormality of the tumor marker and 25 (41.7%) of 60 patients had a recurrence. The positive rate of the marker was 8.1% in CA 15 3, 6.7% in CEA, 4.1% in NCC ST 439, and each rate of recurrence was 56.7%, 48.0%, 33.3%. Rate of recurrence in the negative cases was 12.7%, 13.9, 15.0% respectively and recognized a significant difference statistically (p <0.001) . Of 11 cases (3.8%) shown CA 15 3 abnormal high level, 3 cases (27.2%) had recurrence when we examined in 0 3 metastases to lymph nodes according to markers. 281 cases (96.2%) was normal range in CA15 3. Only 15 cases (5%) had recurrence. It showed a significant difference statistically (p <0.05) . For the cases shown abnormality of the preoperative CA 15 3, careful serial observations are necessary

Disposition of protein-bound 3-nitrotyrosine in rat plasma analysed by a novel protocol for HPLC-ECD

金沢大学医薬保健研究域医学系3-Nitrotyrosine (NTyr) is considered as a biomarker of the generation of reactive nitrogen species (RNS). However, it is still difficult to determine its concentration in biological samples. To develop a reliable and high-throughput method, we optimized the conditions for high performance liquid chromatography and electrochemical detection (HPLC-ECD). The best separation of NTyr was achieved using a highly acidic mobile phase (pH 2.5). The concentration of protein-bound NTyr in plasma protein was 593.6 ± 53.8 fmol/mg in rats treated with lipopolysaccharide (LPS) and 114.4 ± 27.6 fmol/mg in control. After intravenous administration of in vitro-nitrated plasma protein, NTyr concentration decreased; the half-life was 63.4 ± 16.8 h. Consistently, protein-bound NTyr concentration in plasma after LPS treatment declined gradually, but was detectable for 1 week. Our protocol is reproducible and suitable for analysing multiple clinical samples to study RNS production in vivo. © 2007 The Japanese Biochemical Society

Physical properties of the Dome Fuji deep ice core (review)

Recent results of physical analyses of the Dome Fuji ice core are summarized with special attention to new methods introduced in the present studies. Microphysical processes which affect the ice core records are reviewed to better understand the paleoclimatic and paleoenvironmental signals stored

Degradation of Mutant Protein Aggregates within the Endoplasmic Reticulum of Vasopressin Neurons

Misfolded or unfolded proteins in the ER are said to be degraded only after translocation or isolation from the ER. Here, we describe a mechanism by which mutant proteins are degraded within the ER. Aggregates of mutant arginine vasopressin (AVP) precursor were confined to ER-associated compartments (ERACs) connected to the ER in AVP neurons of a mouse model of familial neurohypophysial diabetes insipidus. The ERACs were enclosed by membranes, an ER chaperone and marker protein of phagophores and autophagosomes were expressed around the aggregates, and lysosomes fused with the ERACs. Moreover, lysosome-related molecules were present within the ERACs, and aggregate degradation within the ERACs was dependent on autophagic-lysosomal activity. Thus, we demonstrate that protein aggregates can be degraded by autophagic-lysosomal machinery within specialized compartments of the ER