5,610 research outputs found
The Merging of Traditional Chinese Medicine and Western Medicine in China: Old Ideas Cross-Culturally Communicated Through New Perspectives
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.
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
Isospin singlet (pn) pairing as well as quartetting in nuclei is expected to
arise near the symmetry line . 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
Unconventional superconducting pairing symmetry induced by phonons
The possibility of non-s-wave superconductivity induced by phonons is
investigated using a simple model that is inspired by SrRuO. 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 d 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 SrRuO, providing a plausible explanation of
how the observed spin fluctuations, which clearly favor d 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 SrRuO. These results indicate that phonons
could play a key role in establishing the order-parameter symmetry in
SrRuO, and possibly in other unconventional superconductors.Comment: 6 pages, 5 figures, submitted to Phys. Rev.
- …