173 research outputs found
Planetary Systems in Binaries. I. Dynamical Classification
Many recent observational studies have concluded that planetary systems
commonly exist in multiple-star systems. At least ~20% of the known extrasolar
planetary systems are associated with one or more stellar companions. The
orbits of stellar binaries hosting planetary systems are typically wider than
100 AU and often highly inclined with respect to the planetary orbits. The
effect of secular perturbations from such an inclined binary orbit on a coupled
system of planets, however, is little understood theoretically. In this paper
we investigate various dynamical classes of double-planet systems in binaries
through numerical integrations and we provide an analytic framework based on
secular perturbation theories. Differential nodal precession of the planets is
the key property that separates two distinct dynamical classes of multiple
planets in binaries: (1) dynamically-rigid systems in which the orbital planes
of planets precess in concert as if they were embedded in a rigid disk, and (2)
weakly-coupled systems in which the mutual inclination angle between initially
coplanar planets grows to large values on secular timescales. In the latter
case, the quadrupole perturbation from the outer planet induces additional
Kozai cycles and causes the orbital eccentricity of the inner planet to
oscillate with large amplitudes. The cyclic angular momentum transfer from a
stellar companion propagating inward through planets can significantly alter
the orbital properties of the inner planet on shorter timescales. This
perturbation propagation mechanism may offer important constraints on the
presence of additional planets in known single-planet systems in binaries.Comment: 14 pages, 14 figures, to appear in Ap
Body Temperature Regulation During Exercise and Hyperthermia in Diabetics
Thermoregulatory function, that is, heat dissipative responses such as skin blood flow (SkBF) and sweating to an increased body temperature, is critical during physical work or exercise in warm and hot conditions and during hyperthermia. Thermoregulatory function is associated with individual somatotype, fitness level, normal aging, and physiological status and diseases. Individuals with type 2 diabetes have decreased thermoregulatory responses compared with healthy counterparts, characterized by decreased SkBF and sweating. The decreased SkBF and sweating would be associated with the reduction in nitric oxide bioavailability and endothelial functions in skin vasculatures, also with central mechanisms, and so on. Aerobic exercise training and/or acclimation to the heat improve heat dissipative responses in healthy subjects. The effects of exercise training in type 2 diabetics on glycemic control are well established while it remains unclear that high levels of aerobic fitness or exercise training in diabetics improve thermoregulatory function during heat stress
Influence of Ultrasonic-Shot Peening on Bending Fatigue of TiNi Shape Memory Alloy
The fatigue property of shape memory alloy (SMA) is one of the most important subjects in view of evaluating functional characteristics of SMA elements. In the present study,ultrasonic shot peening (USP) was applied to induce compressive residual stress on the surface layer of TiNi SMA tape and the influence of USP on the bending fatigue life was investigated. The fatigue life of USP-treated tape is longer than that of the as-received tape. The fatigui life of the tape USP-treated with high coverage is longer than that with low coverage. The fatigue life of the USP-treated tape increases in proportion to the hardness on the surface of the tape
A display of pH-sensitive fusogenic GALA peptide facilitates endosomal escape from a Bio-nanocapsule via an endocytic uptake pathway
BACKGROUND: An affibody-displaying bio-nanocapsule (Z(HER2)-BNC) with a hepatocyte specificity derived from hepatitis B virus (HBV) was converted into an affibody, Z(HER2), that recognizes HER2 receptors. This affibody was previously reported to be the result of the endocytosis-dependent specific uptake of proteins and siRNA into target cancer cells. To assist the endosomal escape of inclusions, a helper lipid with pH-sensitive fusogenic ability (1,2-dioleoyl-sn-glycero-3-phos phoethanolamine; DOPE) was conjugated with a Z(HER2)-BNC. FINDINGS: In this study, we displayed a pH-sensitive fusogenic GALA peptide on the surface of a particle in order to confer the ability of endosomal escape to a Z(HER2)-BNC. A GALA-displaying Z(HER2)-BNC purified from yeast uneventfully formed a particle structure. Furthermore, endosomal escape of the particle was facilitated after endocytic uptake and release of the inclusions to the cytoplasm without the cell toxicity. CONCLUSION: The genetic fusion of a GALA peptide to the virus-like particle confers the ability of endosomal escape
Bending Fatigue Property in Nitrogen Ion-Implanted TiNi Shape Memory Alloy Tape
A shape memory alloy (SMA) is expected to be applied as intelligent or smart material since it shows the functional characteristics of the shape memory effect and superelasticity. Most SMA elements,with these characteristics, perform cyclic motions. In these cases,the fatigue property of SMA is one of the most important subjects in view of evaluating functional characteristics of SMA elements. the fatigue properties are complex since they depend on stress,strain,temperature and their hysteresis. If SMA is implanted by high energy ions,the thermomechanical properties of the material may change,resulting in long fatigue life. In the present study, the nitrogen ion implantation was applied to modify the surface of a TiNi SMA tape and the influence of implantation treatment on the bending fatigue properties was investigated
Asymmetric Synthesis of N-Fmoc-(S)-7-aza-tryptophan via Alkylation of Chiral Nucleophilic Glycine Equivalent
Ni(II)-complexes, derived from glycine Schiff bases with chiral tridentate ligands, have been used as powerful tools for the synthesis of structurally diverse tailor-made amino acids. In this manuscript, asymmetric alkylation reaction between chiral nucleophilic glycine derived Ni-complex and 3-(chloromethyl)-1H-pyrrolo[2,3-b]pyridine has been developed under convenient conditions, which affords the corresponding alkylated Ni-complex in 74 % yield and excellent diastereoselectivity (only one isomer). This reaction features convenient conditions and completely controlled diastereoselectivity, which provides a highly valuable approach for asymmetric synthesis of 7-aza-tryptophan
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