Search

In order to study the relationship between the macro-bending loss characteristics of the single-mode fiber and the temperature change, the thermo-optical effect and thermal expansion effect are corrected according to the theoretical formula proposed by Faustini L. Based on this formula, the macro-bending loss of SMF28 and 1060XP single-mode fiber with core-cladding-infinite coating structure under the influence of temperature is simulated and analyzed. The influence of temperature, wavelength, bending radius and other factors on the macro-bending loss of SMF28 single-mode fiber is explored, and the linear fitting results between the temperature and the two kinds of single-mode fibers are obtained. The results show that the macrobending loss increases with the decrease of bending radius, and the increase of wavelength. The loss also decreases with the increase of temperature. Under certain bending radius and wavelength, the macro-bending loss and temperature are in monotonic relationship, which means increasing the number of bending turns can effectively increase the sensitivity to temperature.

Six compounds were isolated from the stems and leaves of Arachis hypogaea, including a new norsesquiterpene, arahyside A (1), and five known compounds, 4-(2-methoxyethyl)benzene-1,2-diol (2), (1(R,S),2(R,S))-1-phenylpropane-1,2-diol (3), tachioside (4), 1,3-benzenediol (5), demethylmedicarpin (6). Extensive spectroscopic methods, containing HR-EI-MS, NMR and ECD were used for structural elucidation of this new compound 1. Furthermore, its cytotoxicity was evaluated by MTT assay. [ABSTRACT FROM AUTHOR]

Carney complex is a syndrome characterized by skin pigmentation abnormalities, myxomas, endocrine tumors/overactivity, and schwannomas. It is caused by a mutation in the PRKAR1A gene that encodes the enzyme protein kinase A regulatory subunit type 1 alpha. A 23-year old male was diagnosed with Carney complex on the basis of spotty skin lentigines on his face and lips, multiple thyroid neoplasms, a right ventricular myxoma, and bilateral testicular tumors. A total bilateral orchectomy was performed and the pathological findings revealed Leydig's cell tumors on one side and a Sertoli cell tumor on the other side. When his first-degree relatives were examined, his mother was found to have Carney complex as well. This is the first reported case of familial Carney complex in China.

Density functional theory has been applied to study the influences of alpha-substituents in aliphatic aldehydes on the enantioselectivities of the (S)-proline-catalyzed direct aldol reactions. Reaction scenarios of three kinds of aliphatic aldehydes were investigated. Four transition states associated with the stereocontrolling step of each reaction have been obtained. They are corresponding to the syn and anti arrangements of enamine intermediates and the si and re attacks to the carbonyl group of an aldehyde. The solvent effect of DMSO was investigated using self-consistent reaction field method based on the polarizable continuum model. The computed energies of transition states explain the origin of the catalysis and enantioselectivities for these (S)-proline-catalyzed aldol reactions and reveal the influences of alpha-substituents in aliphatic aldehydes on the enantioselectivities of these reactions., ((c) 2007 Wiley-Liss, Inc.)