25 research outputs found
Chiral azabicyclo-N-oxyls mediated enantioselective electrooxidation of sec-alcohols
Enantiomerically pure azabicyclo-N-oxyls were prepared from l-hydroxyproline. They mediated enantioselective electrooxidation of racemic sec-alcohols to afford optically active sec-alcohols with moderate to high s value (up to 21)
The seasonal variations of atmospheric 134,137Cs activity and possible host particles for their resuspension in the contaminated areas of Tsushima and Yamakiya, Fukushima, Japan
A large quantity of radionuclides was released by the Fukushima Daiichi Nuclear Power Plant accident in March 2011, and those deposited on ground and vegetation could return to the atmosphere through resuspension processes. Although the resuspension has been proposed to occur with wind blow, biomass burning, ecosystem activities, etc., the dominant process in contaminated areas of Fukushima is not fully understood. We have examined the resuspension process of radiocesium (134,137Cs) based on long-term measurements of the atmospheric concentration of radiocesium activity (the radiocesium concentration) at four sites in the contaminated areas of Fukushima as well as the aerosol characteristic observations by scanning electron microscopy (SEM) and the measurement of the biomass burning tracer, levoglucosan.The radiocesium concentrations at all sites showed a similar seasonal variation: low from winter to early spring and high from late spring to early autumn. In late spring, they showed positive peaks that coincided with the wind speed peaks. However, in summer and autumn, they were correlated positively with atmospheric temperature but negatively with wind speed. These results differed from previous studies based on data at urban sites. The difference of radiocesium concentrations at two sites, which are located within a 1 km range but have different degrees of surface contamination, was large from winter to late spring and small in summer and autumn, indicating that resuspension occurs locally and/or that atmospheric radiocesium was not well mixed in winter/spring, and it was opposite in summer/autumn. These results suggest that the resuspension processes and the host particles of the radiocesium resuspension changed seasonally. The SEM analyses showed that the dominant coarse particles in summer and autumn were organic ones, such as pollen, spores, and microorganisms. Biological activities in forest ecosystems can contribute considerably to the radiocesium resuspension in these seasons. During winter and spring, soil, mineral, and vegetation debris were predominant coarse particles in the atmosphere, and the radiocesium resuspension in these seasons can be attributed to the wind blow of these particles. Any proofs that biomass burning had a significant impact on atmospheric radiocesium were not found in the present study
Clinical Outcome of Patients with Pelvic and Retroperitoneal Bone and Soft Tissue Sarcoma : A Retrospective Multicenter Study in Japan
This study aimed to retrospectively analyze the clinical outcomes of patients with pelvic and retroperitoneal bone and soft tissue sarcoma (BSTS). Overall, 187 patients with BSTS in the pelvis and retroperitoneal region treated at 19 specialized sarcoma centers in Japan were included. The prognostic factors related to overall survival (OS), local control (LC), and progression-free survival (PFS) were evaluated. The 3-year OS and LC rates in the 187 patients were 71.7% and 79.1%, respectively. The 3-year PFS in 166 patients without any distant metastases at the time of primary tumor diagnosis was 48.6%. Osteosarcoma showed significantly worse OS and PFS than other sarcomas of the pelvis and retroperitoneum. In the univariate analyses, larger primary tumor size, soft tissue tumor, distant metastasis at the time of primary tumor diagnosis, P2 location, chemotherapy, and osteosarcoma were poor prognostic factors correlated with OS. Larger primary tumor size, higher age, soft tissue tumor, chemotherapy, and osteosarcoma were poor prognostic factors correlated with PFS in patients without any metastasis at the initial presentation. Larger primary tumor size was the only poor prognostic factor correlation with LC. This study has clarified the epidemiology and prognosis of patients with pelvic and retroperitoneal BSTS in Japan
A Novel Signaling Pathway Mediated by the Nuclear Targeting of C-Terminal Fragments of Mammalian Patched 1
Background: Patched 1 (Ptc1) is a polytopic receptor protein that is essential for growth and differentiation. Its extracellular domains accept its ligand, Sonic Hedgehog, while the function of its C-terminal intracellular domain is largely obscure. Principal Findings: In this study, we stably expressed human Ptc1 protein in HeLa cells and found that it is subjected to proteolytic cleavage at the C-terminus, resulting in the generation of soluble C-terminal fragments. These fragments accumulated in the nucleus, while the N-terminal region of Ptc1 remained in the cytoplasmic membrane fractions. Using an anti-Ptc1 C-terminal domain antibody, we provide conclusive evidence that C-terminal fragments of endogenous Ptc1 accumulate in the nucleus of C3H10T1/2 cells. Similar nuclear accumulation of endogenous C-terminal fragments was observed not only in C3H10T1/2 cells but also in mouse embryonic primary cells. Importantly, the C-terminal fragments of Ptc1 modulate transcriptional activity of Gli1. Conclusions: Although Ptc1 protein was originally thought to be restricted to cell membrane fractions, our findings sugges
The Effect of Trialkyl Phosphites and Other Oil Additives on the Boundary Lubrication of Ceramics: Friction of Silicon-Based Ceramics
Convenient synthesis of an enantiomerically pure bicyclic proline and its N-oxyl derivatives
An enantiomerically pure bicyclic proline derivative was prepared by cis-selective allylation and diastereospecific intramolecular alkylation starting from d-pipecolinic acid. In addition, enantiomerically pure azabicyclo N-oxyls derived from the bicyclic proline worked well as catalysts for the enantioselective electrooxidation of racemic sec-alcohols to afford optically active sec-alcohols in moderate enantiomeric purity
Convenient synthesis of an enantiomerically pure bicyclic proline and its N-oxyl derivatives
Preorganized Cyclic Ξ±,Ξ±-Disubstituted Ξ±βAmino Acids Bearing Functionalized Side Chains That Act as Peptide-Helix Inducers
Preorganized
cyclic Ξ±,Ξ±-disubstituted Ξ±-amino
acids (dAA) bearing functionalized side chains that acted as peptide-helix
inducers, which could be used for solid-phase peptide synthesis, were
designed and synthesized. Furthermore, a helical octapeptide with
the following amino acid sequence was prepared, and its preferred
conformation was analyzed based on its CD spectra: Ac-X<sup>1</sup>EYSAX<sup>2</sup>KA-NH<sub>2</sub> (<b>11</b>: X<sup>1</sup> = Api<sup>C4N3</sup>, X<sup>2</sup> = Ac<sub>6</sub>c). The side-chain
azido functional group of peptide <b>11</b> was efficiently
converted to various 1,2,3-triazole groups via Huisgen 1,3-dipolar
cycloaddition reactions involving different types of alkynes. The
new cyclic dAA derivatives, which combine the advantages of conformational
preorganization and side-chain functional groups, should prove to
be a useful tool for the further development of biologically active
peptides