Search PubMed⌕ Search

Biomedical subjects

P Qian

Publications and source records attributed to P Qian.

9 recordsLinked to original sources
PubMed2001

Time-dependent changes in the carotenoid composition and preferential binding of spirilloxanthin to the reaction center and anhydrorhodovibrin to the LH1 antenna complex in Rhodobium marinum.

Carotenoids were isolated from the cells of Rhodobium marinum, and their structures were determined by mass spectrometry and 1H nuclear magnetic resonance spectroscopy; the carotenoids include lycopene, rhodopin, anhydrorhodovibrin, rhodovibrin and spirilloxanthin. Time-dependent changes in the carotenoid composition in the reaction center (RC) and the light-harvesting complex 1 (LH1) were traced by high-performance liquid chromatography analysis of the extracts. The carotenoid composition changed according to the spirilloxanthin biosynthetic pathway. However, spirilloxanthin having the longest conjugated chain was always preferentially bound to the RC, and anhydrorhodovibrin and other precursors to the LH1.

Alphaproteobacteria↗
PubMed2001

[Raman analysis of SiGe films grown by UHV/CVD].

This paper presents a Raman method, which is no deconstructed, to measure Ge content and strain in SiGe alloy films and some samples, which is grown by UHV/CVD with different Ge content and thickness, have been tested by above method. Two samples among them were measured by DCXRD, the results tested by DCXRD are consistent with Raman results that proves that the method in this paper is reliable and accurate. The SiGe PHMOSFET has been fabricated by the samples, the transconductance reaches 112 ms.mm-1 for the device with 0.5 micron channel.

Alloys↗
PubMed2000

Altered enteroendocrine cell expression in T cell receptor alpha chain knock-out mice.

Mice lacking T cell receptor alpha chain (TCRalpha(-/-)) develop inflammation of the colon. We have examined the effect of this inflammation on the colonic epithelium by studying markers of epithelial cuff, enteroendocrine, and immune cell differentiation. Using immunohistochemical techniques, colons were compared in normal C57/BL6 and murine TCR alpha(-/-) mice aged 2 and 3 weeks and 3-11 months. TCR alpha(-/-) mice aged 3-11 months had histologic evidence of inflammation with increased expression of CD45, CD4+, CD8+, and B220+ cells and a decrease in expression of IgA+ cells. There was a decrease in the number of cholecystokinin, serotonin, and neurotensin enteroendocrine expressing cells in the colon of TCR alpha(-/-) mice. These changes were not present in 2-3-week-old suckling/weaning mice. In contrast, peptide tyrosine tyrosine (PYY), glucagon-like peptide-1, and gastrin expression did not change and small intestinal enteroendocrine cells remained unaltered. The change in colonic enteroendocrine cell expression appears to be a specific response, since only a subset of these cells was altered, and the epithelium was intact by histologic analysis. The absence of functional T cells in TCR alpha(-/-) colon has a marked effect on differentiation of a specific subpopulation of enteroendocrine cells, prior to loss of integrity of the epithelium.

Age Factors↗
PubMed2000

On-line computer aided multi-component analysis using organic elemental analyzer

A computer program of on-line multi-component analysis for an organic elemental analyzer was described. Under the control of the proposed program, an elemental analyzer can perform both normal elemental analysis (EA) and multi-component analysis automatically. Eight mixtures of standard samples and nine synthetic copolymers were performed to check the reliability of program. The analytical results of styrene-N,N'-diisopropylacrylamide copolymer samples were compared with the determined results obtained from ultraviolet visible derivative spectroscopic (DS) method. The results show that the deviations for the mixtures of standard samples are < 2% for two and three components samples. In the case of synthetic copolymers, the average deviation between the two methods is 1.96%. It indicates that the proposed program is applicable for the combustion-GC type organic elemental analyzer.

Journal Article↗
PubMed2000

Isolation and purification of the reaction center (RC) and the core (RC-LH1) complex from Rhodobium marinum: the LH1 ring of the detergent-solubilized core complex contains 32 bacteriochlorophylls.

The reaction center (RC) and the core (RC-LH1) complex were isolated and purified from Rhodobium marinum; together with the LH1 complex [Meckenstock et al. (1992a) FEBS Lett. 311: 128], a complete set of RC, LH1 and RC-LH1 from the same wild-type strain of a purple photosynthetic bacterium can therefore now be made. Comparison of the BChl a/BPhe a ratio (determined by HPLC) between the RC and the RC-LH1 complexes lead us to the determination of the number of BChls in the LH1 ring to be 32.06+/-2.90, indicating that the LH1 ring from Rh. marinum consists of 16 alphabeta subunits.

Bacteria↗
PubMed2000

[Effects of vitamin E and vitamin C on nonenzymatic glycation and peroxidation in experimental diabetic rats].

SD rats were peritoneally injected with streptozotocin (STZ) to establish diabetic animal model. The changes of nonenzymatic glycation and peroxidation in rats supplemented with vitamin C and/or vitamin E during five weeks were investigated. It was found that the glycated hemoglobin, glycated LDL, renal cortical AGEs and MDA in sera and renal cortex significantly decreased after supplementation of vitamins E and C jointly. It was also observed that the MDA in serum and the cortex of kidney but not glycated hemoglobin, glycated LDL and AGEs significantly decreased in the groups supplemented with vitamin C or vitamin E separately. The results suggested that joint supplementation of vitamin C and vitamin E could inhibit nonenzymatic glycation obviously and peroxidation in diabetic rats and protect the kidney from damage under hyperglycemia.

Animals↗
PubMed1995

Chinese character operating system of traditional Chinese medicine and pharmacology (TCMP).

With the development in research, teaching and literature work in traditional Chinese medicine and pharmacology (TCMP) by means of computers, it has been found that the existing Chinese character operative systems cannot meet the need of carrying out information processing and software development in this field, since these systems do not include many of the common and special terms in TCMP. This makes it inconvenient to exchange academic thoughts in information processing in this field with our colleagues at home and abroad and greatly affects the sharing of the literature data in TCMP. It is therefore necessary to develop a Chinese character operating system applicable to the use of computers in the research of TCMP. Recently, we have developed jointly a Chinese character operating system of TCMP. This system is based on the original GB2312-80 Chinese character international code, to which are added 1,150 Chinese characters commonly used in TCMP. The five-stroke code, which make input possible according to word forms, are used for the input of expanded words. Besides, the system also provides the codes of a number of common names of Chinese materia medica, acupoint names, common terms in traditional Chinese medicine (TCM), TCM disease names, names of classic TCM works, etc. It also provides a convenient character-creating software. We hope that our work will lead to discussions concerning the difficult problems in computer processing of TCMP literature, i.e. the Chinese character.

Database Management Systems↗
PubMed1987

A comparison of different photosensitizing dyes with respect to uptake C3H-tumors and tissues of mice.

Nine dyes, all potential sensitizers for photodynamic cancer therapy (PDT), were injected in mice with C3H mammary carcinomas. Twenty-four hours later the animals were sacrificed and the dye concentrations in tumors and 9 other tissues were measured by means of spectrofluorimetry. The 9 dyes were: Photofrin II (PII), hematoporphyrin (HP)-di-hexyl-ether, PSD-007 (a sensitizer used in clinical trials in China), tetraphenyl porphine tetrasulfonate (TPPS4), tetra(3-hydroxy phenyl)porphyrin (3THPP), aluminium phthalocyanine tetrasulfonate (AlPCTS), aluminium phthalocyanine (AlPC), chlorin e6 (Chl e6) and merocyanine 540 (MC 540). The porphyrin precursor delta-aminolevulinic acid was also tested and found to induce porphyrin fluorescence in tumors and some other tissues. The best tumorlocalizer of those tested was 3THPP. This drug also showed a favorable tissue distribution. The following dyes showed lower skin/tumor concentration ratios than PII (the most widely used dye for PDT): Chl e6, PSD-007, HP-di-hexyl-ether and 3THPP. Low brain/tumor ratios were found for: PSD-007, HP-di-hexyl-ether, 3THPP, TPPS4 and AlPCTS.

Animals↗