Biomedical subjects
Publications and source records attributed to G Xu.
This paper deals with the microscopic identification of the bulbs of 5 Fritillaria species from Yunnan Province, namely: F. cirrhosa, F. cirrhosa var. purpurea, F. cirrhosa var. viridiflava, F. delavayi and F. crassicaulis. Based on the shape, size, hilum and striation of the starch grain and the cuticular veins of the upper epidermis cell of the scales, these species could be distinguished obviously.
The observation of powder were carried out on fruits of 10 kinds of plants belonging to Genus Actinidia. The results pointed out obvious difference among the above species, which could be considered as one of the important evidence for identification.
By herbological study, medicinal plants from Viola used as drugs are first recorded in the book "52 Diseased Preparation". The plants used as drugs in the ancient mainly are V. yedoensis, V. invospicus, V. diffusa, V. verecunda, V. davidii, V. moupinensis and V. patrinii.
The total nitrogens, amino acids, fatty acids, Inorganic elements of 12 medicinal animals of syngnathidae have been determined. It will provide scientific evidence for development of the medicinal resources and the establishment of quality standards.
A survey on medicinal resources shows 12 species belonging to 7 genera of Syngnathidae are used as traditional Chinese medicine and some problems about cultivated Haima have been discussed.
The morphological characters and commercial idendification on medicinal materials named "Hailong" has been reported. The results of identification of 48 commercial samples indicated "Hailong" is adulterated with Halicampus koilomatodon, Trachyrhamphus serratus and Microphis boaja, Solenognathus güntheri besides three species accepted by Pharmacopoeia.
The SEM observation of the medicinal meterials "Hailong" have been carried out. The results showed there are significantly difference among 7 species "Hailong".
The morphological characters and commercial identification on Haima has been reported. The results of identification of 60 commercial samples indicated that all of Haima was the species accepted by Pharmacopoeia. Hippocampus kelloggi, H. histrix, H. kuda and H. trimaculatus were mainly used in Hainan, Guangdong and Fujian Province; H. japonicus was mainly used in Shandong and Liaoning Province; Imported Haima was H. histrix.
In this paper, a method for determination of thiodicarb by reversed-phase high performance liquid chromatography (RP-HPLC) is presented. Analysis was performed on a 250 mm x 4.6 mm i.d. octadecylsilica (ODS or C18) bonded phase column in 8 minutes. Methanol/water mobile phase was used. Ultraviolet detector was used for detection at 232 nm wavelength. The internal standard method (using dimethyl phthalate as the internal standard) was employed. The linearity of the method was verified. The relative standard deviation (RSD) of determination for 75% thiodicarb wetted-powder was 0.18%. The average recovery was 99.89%. The method has been used for analysis of pesticide products and control of production.
A convenient and efficient method for analysis of phthalate esters (PEs) in plants was developed. PEs in plants were extracted with dichloromethane by ultrasonication, separated by chromatography with a column chromatography packed with 10-40microm sillica and then determined by HPLC on a 250mm x 4.6mm i.d. ODS column using MeOH/H2O (88:12) as mobile phase and UV detection at 228nm. The minimum detectable limits for diethyl phthalate (DEP) and diethylhexyl phthalate (DEHP) were 47pg and 85pg respectively. The overall recoveries of PEs were found to be 85%-101%. The method has been satisfactorily applied to the determination of plant samples.
Based on a mass balance equation, in this paper, the kinetic model of chromatography including influence of the radial diffusion on the mass transfer process is set up. Based on the hypothesis of Giddings, this model has been simplified. In this way, the expressions of the first moment, the second and the third central moment for this model are derived by Laplace transform in detail. The results show the radial diffusion affects not only the column efficiency, the peak spreading and the peak symmetry, but also the retention time.
A method for analysis of residual toluene in plastic packing bags by gas chromatographic headspace analysis is presented. This method is very simple and accurate. It only requires one column: 0.5 m x 2 mm i.d. packed with 102 white support DMCS coated with 20% PEG-20M. The relation between the preheating temperature of sample and the peak height of toluene can be approximately expressed as H=4.156e(0.126T). The precision of this method is 4% and its detectable limit is 0.031 mg (toluene)/m2.
A simplex optimization method developed for the automatic gas chromatography is described in this paper. The instrument was developed by ourself based on a gas chromatograph and an auto-sampler, which are controlled by a computer through several assisting circuit boards. A series of chromatographic function SCRF is used in this method for searching the best column temperature for gas chromatographic separation of a given sample. A real sample is used for probation of this method and the results are discussed.
The radiationless quantum yields ( phi(nr) ) of phenothiazine (PTH). N-phenyl phenothiazine (PHZ). N-(2-pyridine) phenothiazine (PYZ) and model compound p-N, N-dimethylaminobenzonitrile (DMABN)in benzene were measured. The effects of solvents on phi(nr) of DMABN,PHZ,PYZ and PTH were investigated respectively. It was found that phi(nr) of PYZ and DMABN were dependent on the solvent polar parameter (E(T)(30)) . From the results of radiationless quantum yields and combining the state and dynamic fluorescence spectra, it is proved that PYZ as well as DMABN appears TICT property.
The 1, 10-phenanthroline-phthalate complexes of europium and terbium have been synthesized. Two series of mixed complexes, mechanical ground complexes (series 1) and chemical synthesized with mixed EuCl3 and TbCl3 solutions (series 2), have been also prepared. Fluorescence studies on all of the samples were performed. The results of their fluorescence spectra excited by 365nm UV-light showed that there are interactions between europium ions and terbium ions in these two kinds of mixed complexes. Their fluorescence intensities strongly changed especially for chemical synthesized mixed complexes, in which the fluorescence intensities of europium ions were greatly sensitized by terbium ions and those of terbium ions were strongly quenched by europium ions. But the peak positions of their emission bands did not shift obviously. The structure of these complexes have been characterized by FT-IR spectra. The results suggested that no free COOH groups exist and all of the nitrogen atoms of 1, 10-phenanthroline molecules coordinate to rare earth ions in all of these complexes.
A Molfig software has been developed for displaying the structure and vibrational mode of molecule in our lab. Various functions and a friendly interface are equipped in the software. The testing results showed that the software may enhance our understanding of the relationship between the vibrational behavior and the structure of molecules.
The quantum yields of triplet state formation ( phiT ) of acridine, benzophenone. phenothiazine and phenanthrene were measured with anthracene as calibrating compound by the means of pulsed laser photoacoustic calorimetry. It was found that phiT of these compounds were not in accordance with the literature results except acridine due to slow response of PZT transducer. But the better results could be obtained by using deconvolution method to eliminate the effect of respose of the transducer.
We have reported that cellular retinol-binding protein-1 (CRBP-1) is transiently expressed by arterial smooth muscle cells during experimental intimal repair (P. Neuville, A. Geinoz, G. Benzonana, M. Redard, F. Gabbiani, P. Ropraz, G. Gabbiani: Am J Pathol 1997, 150:509-521). We have examined here the expression of CRBP-1 during wound healing after a full-thickness rat skin wound. CRBP-1 was transiently expressed by a significant proportion of fibroblastic cells including myofibroblasts. Expression started 4 days after wounding, reached a maximum at 12 days, and persisted up to 30 days when a scar was formed. After wound closure, most CRBP-1-containing fibroblastic cells underwent apoptosis. We have further investigated CRBP-1 expression in rat fibroblasts cultured from different organs. CRBP-1 was abundant in lung and heart fibroblasts and was detected in decreasing amounts in muscle, tendon, subcutaneous tissue, and granulation tissue fibroblasts. Dermis fibroblasts contained no detectable levels of CRBP-1. All-trans retinoic acid and transforming growth factor-beta1 inhibited cell proliferation and increased CRBP-1 expression in fibroblastic populations except dermis fibroblasts. We demonstrate that during granulation tissue formation a subpopulation of fibroblastic cells express CRBP-1 de novo. We also demonstrate that CRBP-1 expression by fibroblasts is regulated in vitro by retinoic acid and transforming growth factor-beta1. Our results suggest that CRBP-1 and possibly retinoic acid play a role in the evolution of granulation tissue.