5,560 research outputs found

    The Merging of Traditional Chinese Medicine and Western Medicine in China: Old Ideas Cross-Culturally Communicated Through New Perspectives

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    The People\u27s Republic of China is engaged in reforms which involve development of its economic, cultural, educational, and political processes. The need for reform has been realized as China has fallen behind the development of the western world in many areas. China closed its doors to the outside world in 1949, and it experienced limited interaction with the outside world until reform began in 1979

    Effects of niacin restriction on sirtuin and PARP responses to photodamage in human skin.

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    Sirtuins (SIRTs) and poly(ADP-ribose) polymerases (PARPs), NAD(+)-dependent enzymes, link cellular energy status with responses to environmental stresses. Skin is frequently exposed to the DNA damaging effects of UV irradiation, a known etiology in skin cancer. Thus, understanding the defense mechanisms in response to UV, including the role of SIRTs and PARPs, may be important in developing skin cancer prevention strategies. Here, we report expression of the seven SIRT family members in human skin. SIRTs gene expressions are progressively upregulated in A431 epidermoid carcinoma cells (SIRTs1 and 3), actinic keratoses (SIRTs 2, 3, 5, 6, and 7) and squamous cell carcinoma (SIRTs 1-7). Photodamage induces dynamic changes in SIRT expression with upregulation of both SIRT1 and SIRT4 mRNAs. Specific losses of SIRT proteins occur early after photodamage followed by accumulation later, especially for SIRT4. Niacin restriction, which decreases NAD(+), the sirtuin substrate, results in an increase in acetylated proteins, upregulation of SIRTs 2 and 4, increased inherent DNA damage, alterations in SIRT responses to photodamage, abrogation of PARP activation following photodamage, and increased sensitivity to photodamage that is completely reversed by repleting niacin. These data support the hypothesis that SIRTs and PARPs play important roles in resistance to photodamage and identify specific SIRTs that respond to photodamage and may be targets for skin cancer prevention

    Isospin singlet (pn) pairing and quartetting contribution to the binding energy of nuclei

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    Isospin singlet (pn) pairing as well as quartetting in nuclei is expected to arise near the symmetry line N=ZN=Z. Empirical values can be deduced from the nuclear binding energies applying special filters. Within the local density approximation, theoretical estimates for finite nuclei are obtained from results for the condensation energy of asymmetric nuclear matter. It is shown that the isospin singlet condensation energy drops down abruptly for |N-Z|~4 for medium nuclei in the region A=40. Furthermore, alpha-like quartetting and the influence of excitations are discussed.Comment: 19 pages, 19 figures, submitted to PR

    Le Cong Co: A Vietnamese Legacy of Ethical Leadership

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    Unconventional superconducting pairing symmetry induced by phonons

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    The possibility of non-s-wave superconductivity induced by phonons is investigated using a simple model that is inspired by Sr2_2RuO4_4. The model assumes a two-dimensional electronic structure, a two-dimensional spin-fluctuation spectrum, and three-dimensional electron-phonon coupling. Taken separately, each interaction favors formation of spin-singlet pairs (of s symmetry for the phonon interaction and dx2y2_{x^2-y^2} symmetry for the spin interaction), but in combination, a variety of more unusual singlet and triplet states are found, depending on the interaction parameters. This may have important implications for Sr2_2RuO4_4, providing a plausible explanation of how the observed spin fluctuations, which clearly favor dx2y2_{x^2-y^2} pairing, may still be instrumental in creating a superconducting state with a different (e.g., p-wave) symmetry. It also suggests an interpretation of the large isotope effect observed in Sr2_2RuO4_4. These results indicate that phonons could play a key role in establishing the order-parameter symmetry in Sr2_2RuO4_4, and possibly in other unconventional superconductors.Comment: 6 pages, 5 figures, submitted to Phys. Rev.
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