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Z H Wan

Publications and source records attributed to Z H Wan.

3 recordsLinked to original sources
PubMed2001

Electron crystallographic image-processing investigation and superstructure determination for (Pb0.5Sr0.3Cu0.2)Sr2(Ca0.6Sr0.4)Cu2Oy.

An electron crystallographic image-processing technique based on the combination of high-resolution electron microscopy and electron diffraction has been developed to investigate the commensurate structural modulation in the high-Tc superconductor (Pb0.5Sr0.3Cu0.2)Sr2(Ca0.6Sr0.4)Cu2Oy. After symmetry averaging, a structure image was obtained by image deconvolution at the resolution limited by that of the electron microscope. Then phase extension was employed to enhance the image resolution up to about 1.25 A by means of the electron diffraction data corrected with an empirical method. In the final projected potential map, the occupational and/or positional modulation is clearly observed for all atoms, including oxygen. The key points of determining superstructures by the technique are studied and discussed.

Journal Article↗
PubMed1995

[Role of afferent renal nerves in 2K2C Goldblatt hypertension].

In order to study the role of afferent renal nerves in 2K2C Goldblatt hypertension, the renal afferent nerves were selectively lesioned by bilateral T9-L2 spinal dorsal rhizotomy before clipping (internal diameter, 0.3 mm) of birenal arteries. Systolic blood pressure of the rat was measured by tail-cuff method. Concentrations of catecholamines, Ang II, and aldosterone were determined respectively by HPLC-EC and RIA, and vascular structural changes were measured by blood vessel micro-image analysis system coupled with a computer. The results showed that the concentrations of NE and E in medulla oblongata, adrenal gland and plasma, and of plasma Ang II and aldosterone as well as body weight of the rat were all significantly increased. The heart coefficient (heart wt/body wt), the media thickness, and the media thickness/lumen diameter in superior mesenteric arteries were also increased in 2K2C hypertensive rats (clipping, 6 wk) as compared with those in control rats. Bilateral rhizotomy delayed development of 2K2C hypertension and prevented above-mentioned vascular structural changes, the NE and E concentrations of medulla oblongata, adrenal gland and plasma were all decreased, hypothalamic NE and E were increased, and plasma Ang II level was not significantly changed. These results suggest that afferent renal nerves may play a partial role in the development of hypertension in 2K2C rats by activating sympathetic nervous system as a result of affecting metabolic activities of brain catecholaminergic neurons, and that high-plasma Ang II and aldosterone as well as heart hypertrophy and proliferation of vascular smooth muscle cells may also participate in the pathogenesis of hypertension in 2K2C rats.

Afferent Pathways↗