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It is previously known that under inflation alone a spherical rubber membrane balloon may bifurcate into a pear shape when the tension in the membrane reaches a maximum, but the existence of such a maximum depends on the material model used: the maximum exists for the Ogden model, but does not exist for the neo-Hookean, Mooney–Rivlin or Gent model. This paper discusses how such a situation is changed when a pressurized dielectric elastomer balloon is subjected to additional electric actuation. A similar bifurcation condition is first deduced and then verified numerically by computing the bifurcated solutions explicitly. It is shown that when the material is an ideal dielectric elastomer, bifurcation into a pear shape is possible for all material models, and similar results are obtained when a typical non-ideal dielectric elastomer is considered. It is further shown that whenever a pear-shaped configuration is possible it has lower total energy than the co-existing spherical configuration. [ABSTRACT FROM AUTHOR]

Nd was produced by irradiation of an enriched target of Ru with a Ar beam and studied by using a helium-jet fast tape transport system in combination with X- $ \gamma$ and $ \gamma$ - $ \gamma$ coincidence measurements. A 2.6s isomer of Nd was observed for the first time and tentatively proposed to be the configuration of 1/2[411]. [ABSTRACT FROM AUTHOR]

Our previous experimental method and results of (EC+β+) decay for the medium-heavy nuclei 153Er, 157Yb, 209Fr, 128Ce, 130Ce, 128Pr, 130Pm and 140Tb have been briefly summarized. The observed low-lying states in their daughter nuclei and a 11/2- isomeric state in 133Pr have been reviewed in a systematic way and compared with different model calculations. Finally, some questions have been put forward for further study and discussion. [ABSTRACT FROM AUTHOR]

The proton-rich isotope 133Sm was produced via the fusion evaporation reaction 40Ca + 96Ru. Its β-delayed proton decay was studied by p-γ coincidence in combination with a He-jet tape transport system, and half-lives, proton energy spectra, γ-transitions following the proton emission, as well as β-delayed proton branching ratios to the low-lying states in the grand-daughter nucleus were determined. Comparing the observed β-delayed proton branching ratios with statistical model calculations, the best agreement is found assuming that only one level with the spin of 3/2 in 133Sm decays or two levels with the spins of 1/2 and 5/2 decay with similar half-lives. The configuration-constrained nuclear potential energy surfaces of 133Sm were calculated using the Woods-Saxon-Strutinsky method, which suggests a 1/2- ground state and a 5/2+ isomer with an excitation energy of 120keV. Therefore, the simple (EC+β+) decay scheme of 133Sm in Eur. Phys. J. A 11, 277 (2001) has been revised. In addition, our previous experimental data on the β-delayed proton decay of 149Yb reported in Eur. Phys. J. A 12, 1 (2001) was also analyzed using the same method. The spin-parity of 149Yb is suggested to be 1/2-. [ABSTRACT FROM AUTHOR]

Statins block de novo synthesis of cholesterol by inhibiting the enzyme, HMG CoA reductase. The product of this reaction, mevalonic acid, is also a precursor of isoprenoids, molecules required for the activation of signaling G-proteins, such as Ras. Signal transduction pathways involving Ras are important for cell survival and this may be why statins induce apoptotic death of several cell types. Given that statins are used to treat vascular disease, surprisingly no studies have been conducted on vascular endothelial cells. Here we show that fluvastatin (FS), at concentrations from 1–2 μM, blocks growth and induces apoptosis of the endothelial cell line, EA.hy 926. Considerable redundancy is known to exist in cell signaling and in vivo toxicity of FS might be prevented by other signaling pathways, like those activated by adrenal or sex steroids. RT-PCR analysis revealed the expression of the androgen and glucocorticoid receptor in EA.hy 926 cells. Although the androgen, dihydrotestesterone (DHT) had no effect, the glucocorticoid, dexamethasone (Dex), blocked FS-induced apoptosis. Cell cycle analysis revealed that 24 h exposure to FS prevented cells from leaving G1 and 24–48 h later a marked sub-G1 peak was observed. Dex was able to reduce the sub-G1 peak, but it failed to block accumulation of cells in G1, indicating that it’s effect was specific for blockade of apoptosis, and not specific to an effect on FS alone. This study strongly suggests that glucocorticoids have a role to play in preventing vascular injury and they may provide the reason why statins are not inherently toxic to vascular endothelial cells, in vivo. [Copyright &y& Elsevier]

The very neutron-deficient nuclide 129Pm was produced via the 92Mo(40Ca, p2n) reaction and identified for the first time by using the X-γ coincidence in combination with a He jet tape transport system. According to the decay curve of a 99 keV γ-ray which corresponds to the known &frac52; → ½ transition in the daughter nucleus 129Nd of the 129Pm decay, the half-life of 129Pm was determined to be 2.4(9) s. Based on the nuclear potential energy surface (PES) calculations, the ground-state spin-parity of 129Pm was predicted as &frac52; which is favorable to feed a &frac52; low-lying state in the daughter nucleus 129Nd via the (EC 1β+) decay. [ABSTRACT FROM AUTHOR]

Bio-inspired tunable lenses are composed of soft dielectric elastomer membranes, clear liquids and rigid frames. Being a new type of optical lens, its focus can be adjusted by the applied voltage. For this type of micro-lens to be practically used in real life, the functional relationship between the voltage and the focus needs to be determined, together with the impact of lens parameters such as the pre-stretching of soft dielectric elastomer membranes, the scale and the volume of liquids on this relationship, as well as on the maximum change of lens focus. In this paper, a compact computational model is proposed based on the assumption of homogeneous deformation and application of energy methods. The model results fit well with the experimental data. By using this model, the relationship curve between the applied voltage and the focus has been given, and it has been verified that such lens will not fail in operation. Finally, by analyzing the three parameters of lens, we can also demonstrate that the pre-stretching of dielectric membranes and the scale affect the relationship between the applied voltage and the focus the most, with the volume of liquids having the least impact. [ABSTRACT FROM AUTHOR]

Samples of La[sub 0.6]Sr[sub 0.4]Fe[sub 3-δ] with varying oxygen vacancy contents were prepared by heating them in different gas flows. Magnetization measurement showed that samples with low oxygen vacancies have a magnetic ordering temperature in the range of 300-325 K while those with 9%-12% oxygen vacancies have a magnetic ordering temperature of 800 K and higher. Mössbauer spectra at 300 K exhibit paramagnetic or weak magnetic characteristics for the N[sub 2], O[sub 2], and air-quenched samples, whereas an average hyperfine field of 52 T is found for the CO/CO[sub 2] reduced samples. The heat treatment in the reducing atmosphere creates oxygen vacancies and increases unit cell volume. However, the Fe-O bond length remains nearly constant, resulting in distortion/rotation of the oxygen octahedra which increases the Fe-O-Fe bond angle as much as 12 degrees. This dramatically affects the Fe-O-Fe superexchange coupling and plays a key role in the increase of the Nèel temperatures. [ABSTRACT FROM AUTHOR]

Pneumatic actuation offers a convenient way to tune pattern formation in periodically porous elastomers. In this paper, we study deflation-induced buckling in periodically porous elastomers using both an analytical approach and the finite element method. By applying the Euler–Bernoulli beam model, an analytical bifurcation condition is derived using the energy approach, from which the critical buckling load can be identified analytically. Furthermore, the theoretical results are qualitatively validated by the corresponding finite element ones. It is noted that a unit cell will be assigned in finite element simulations, and usually, such a choice can be varied. In order to ensure the consistency of different unit cells in finite element simulations, we assign two representative cases and identify the proper boundary conditions that should be applied. By applying the same solution procedure, we carry out a stability analysis and analytically reveal the effect of an initial geometrical imperfection on the buckling behavior. Finally, the variation of band gaps in pneumatically activated periodic elastomers is studied by means of the finite-element method. It is hoped that the present analysis could provide useful insight not only into pattern formation in periodically porous elastomers under deflation but also into the choice of the unit cell in numerical simulations. • We theoretically analyzed the bifurcation of a periodically porus elatomer under pneumatic actuation. • We performed a finite element simulation, also clarified two misunderstandings in the existing literature. • We conducted stability and bistability analysis based on the derived analytical model. • An analysis on the tunable band gaps of the structure with the variation of hole diameter is conducted. [ABSTRACT FROM AUTHOR]

In order to achieve rapid and efficient decomposition of organic pollutants, semiconductor materials with heterostructure are applied because of the effective electron hole pair separation via the interfacial junction. Among the semiconductor materials, TiO2 and boron doped diamond (BDD) with unique excellent properties are ideal building blocks to form heterojunction structure, which can be used in waste water treatment. In this work, the TiO2 nanorods (NRs) with different morphology have been deposited on BDD films with a ZnO buffer layer via hydrothermal method. It is demonstrated that the reaction temperature has a great effect on the morphology and crystallinity of the TiO2 NRs on BDD film. The crystallinity of TiO2 NRs can be improved by increasing the reaction temperature. Experimentally, it shows that the TiO2 NRs/ZnO/BDD heterojunction shows enhanced photocatalytic activity with respect to TiO2 NRs/ZnO and TiO2 NRs/BDD heterojunctions respectively. [ABSTRACT FROM AUTHOR]

Males who have sex with men (MSM) are considered at high risk of blood-borne and sexually transmitted infections (STIs), mainly due to the practice of unsafe sex, often combined with drug use and needle-sharing. A cross-sectional study was designed for the detection of genital mycoplasmas during the period from March 2009 to May 2010 in Jiangsu province. This work was approved by the Research ethics Committee of Jiangsu Centers for Diseases Prevention and Control (CDC), and written consent was obtained from all participants. In total, 243 human immunodeficiency virus-1 (HIV-1)-infected MSM were screened in this study. Over half of them reported a history of sexual activity with females (65.0 %), and 26.3 % reported a history of sexually transmitted diseases (STDs) other than HIV. 44.0 % of patients were in the first 2 years of their HIV infection, and 72.4 % were still in HIV progression. Of the 243 analyzed samples, all were positive for at least one kind of mycoplasma. The infection rates of Mycoplasma genitalium, M. fermentans, M. penetrans, and M. pirum were 25.5, 9.9, 2.5, and 18.5 %, respectively. The M. genitalium infection was associated with a history of sexual activity with females, and those who had sex with females showed higher infection rates. Six M. penetrans-positive patients were still in HIV infection progression and did not receive highly active antiretroviral therapy (HAART). Men who perform this particular behavior are at higher risk of Mycoplasma infections. Further molecular and epidemiological cohort studies with larger populations are needed in order to identify the role of Mycoplasma infections in HIV-1-infected MSM. [ABSTRACT FROM AUTHOR]