Biomedical subjects

Guoliang Li

Publications and source records attributed to Guoliang Li.

7 recordsLinked to original sources

PubMed2006

Core-corona polymer composite particles by self-assembled heterocoagulation based on a hydrogen-bonding interaction.

Poly(ethylene glycol dimethacrylate-co-acrylic acid) (poly(EGDMA-co-AA)) small microspheres were effectively self-assembled on poly(ethylene glycol dimethacrylate-co-4-vinylpyridine) (poly(EGDMA-co-VPy)) surfaces to form a core-corona structure with a raspberry-like polymer composite by a hydrogen interaction mechanism through an affinity complex between the carboxylic acid group and pyridine group. The control of coverage of the poly(EGDMA-co-AA) corona on the surface of poly(EGDMA-co-VPy) was studied in detail via adjustment of the nature of the mass ratio between the core and corona. The effects of the pH and solvent used on the morphology of the self-assembled core-corona polymer composites were investigated. The nature of the interaction between the core and corona polymer particles was identified as hydrogen bonding with FT-IR spectroscopy.

Acrylates↗

PubMed2006

[Major chemical components of poultry and livestock manures under intensive breeding].

Owing to the wide use of feed additives in modern intensive poultry and livestock production, the major components and their concentrations of domestic animal manures may be greatly changed, as compared with those in traditional breeding. An investigation on the 61 samples of chicken, pig and pigeon manures from the intensive poultry and livestock farms of Guangdong Province showed that the concentrations of total N, P and K in chicken and pig manures were obviously higher than those of traditional breeding, and the P/N ratio of three test manures was greater than that of common crops. The concentrations of total soluble salts (TSS) of test manures averaged 49.0, 20.6 and 60.3 g x kg(-1) , respectively, which were mainly composed of the sulfate and chloride of potassium and sodium. The mean concentrations of Cu, Zn and As reached 107.5, 366.6 and 21.6 mg x kg (-1) in chicken manure, 765.1, 1128.0 and 89.3 mg x kg(-1) in pig manure, and 56.1, 210.9 and 2.9 mg x kg(-1) in pigeon manure, respectively. These manures were low in Pb, Cd and Cr contents, from non-detectable to 12.0 mg x kg(-1). According to the limiting criteria of heavy metals in fertilizers, the Cu, Zn and As in the three manures were the major elements exceeding the limits, especially for Zn.

Animals↗

PubMed2005

Raspberry-like composite polymer particles by self-assemble heterocoagulation based on a charge compensation process.

Nano-sized poly(ethylene glycol dimethacrylate-co-acylic acid) (poly(EGDMA-co-AA)) were effectively self-assembled on poly(divinylbenzene-co-styryl methylpyridinium chloride) (poly(DVB-co-StMPyCl)) surfaces to form the raspberry-like composite by a charge compensation mechanism through the affinity complex between carboxylic group and pyridinium group. The effects of pH and salt electrolyte on the morphology of the self-assembled polymer composites were investigated. The resulting heterocoagulates were highly stable in water and acid solution. These heterocoagulates were reversible through the self-assembly in acidic or neutral media and the dissociation in the basic medium due to the charge compensation through the strong affinity complex between hydroxide anion and pyridinium group cation. The resulting heterocoagulates were characterized with scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). As a result, a new method for tuning the structure of a charge compensation directed polymer composite was developed.

Composite Resins↗

PubMed2004

Imidazole facilitates electron transfer from organic reductants.

In cyclic voltammetry studies at pH 8, imidazole facilitates oxidation of organic compounds that normally lose hydrogen atoms. High concentrations of imidazole shift the oxidizing wave of ascorbic acid, 2,3-dimethoxy-5-methyl-1,4-hydroquinone, and the vitamin E analogue Trolox toward lower potentials. By contrast, imidazole has no effect on the cyclic voltammogram of methyl viologen, which undergoes electron rather than hydrogen-atom transfer. The effect of imidazole is observed at pH 8.0 but only to a lesser extent at pH 5.5 indicating that imidazole must be unprotonated to facilitate oxidation. Digital simulation shows that these results are consistent with a mechanism in which imidazole acts as a proton acceptor permitting concerted proton/electron transfer by the organic reductant.

Ascorbic Acid↗

PubMed2002

[Perinatal outcome of twin pregnancies conceived by assisted reproductive techniques and those conceived spontaneously].

OBJECTIVE: To investigate perinatal outcomes of twin pregnancies conceived by assisted reproductive techniques and those conceived spontaneously. METHODS: The pregnant complications, delivery situation and neonatal outcomes of 104 twin pregnancies conceived by assisted reproductive techniques were compared to 173 spontaneous ones. RESULTS: (1) The women of twin pregnancies conceived by assisted reproductive techniques were (31.2 +/- 3.7) years old while the spontaneous ones were (27.8 +/- 3.5) years old. There was significant difference between two groups (P < 0.05). (2) There were also significant differences in the incidence of premature delivery and gestational diabetes mellitus or impaired glucose tolerance(P < 0.01) between two groups. There were 70 cases (67.3%) premature delivery in assisted reproduction group, while 78 cases (45.1%) in spontaneous group. There were 16 cases (15.4%) gestational diabetes mellitus or impaired glucose tolerance in assisted reproduction group, while 4 cases (2.3%) in spontaneous group. (3) Cesarean sections were more frequently performed in assisted reproduction group (79 cases, 76.0%) than in spontaneous group (113 cases 65.3%). (4) There were no statistically significant differences in perinatal deaths, congenital malformations, neonatal asphyxia between two groups (P < 0.05). CONCLUSION: The women of twin pregnancies conceived by assisted reproductive techniques were older than those conceived spontaneously. The incidence of premature delivery, gestational diabetes mellitus or impaired glucose tolerance and cesarean section were higher in assisted reproduction group. However, no statistically significant differences in perinatal morbidity were found between the two groups.

Adult↗

PubMed2002

Molecules for materials: structures, thermochemistry, and electron affinities of the digermanium fluorides Ge2Fn/Ge2Fn- (n = 1-6): a wealth of unusual structures.

A systematic investigation of Ge2Fn/Ge2Fn- systems was carried out with five density functional theory (DFT) methods in conjunction with DZP++ basis sets. For each compound various structures, including minima, transition states and other energetically low lying stationary points, were optimized. The geometries and relative energies are discussed and compared. Adiabatic electron affinities, vertical electron affinities and anion vertical detachment energies are reported. Three types of dissociation energies pertaining to the global minima for each compound are reported. The theoretical predictions are in good agreement with the limited available experimental results. Many unusual structural features are predicted for these systems. Neutral Ge2F is predicted to have a bridged C2v structure, while its anion is very floppy, with the bridged structure very slightly favoured. The Ge2F2 molecule is predicted to have the butterfly structure known from experiment for Si2H2, while the Ge2F3- ion has a trans-bent structure. Ge2F3 is predicted to have an unprecedented FGe-F-GeF structure with no Ge-Ge bond, while its anion has a somewhat more conventional monobridged structure, analogous to that of the nonclassical vinyl cation. Neutral Ge2F4 has a dibridged structure of C2h symmetry, while its anion has a trans-bent structure with a very long Ge-Ge bond. The Ge2F5 molecule is doubly bridged and has no Ge-Ge bond, while the anion is of the type F2Ge-F-GeF2, again with no Ge-Ge bond. Ge2F6 has the anticipated ethane structure, as does its anion, but with a very long Ge-Ge bond. The adiabatic electron affinities (EAad) are predicted to be 2.12 (Ge2F), 2.03 (Ge2F2), 2.02 (Ge2F3), 1.64 (Ge2F4), 4.57 (Ge2F5), and 2.66 eV (Ge2F6), respectively, by the BHLYP method, which is regarded as the best method in the present paper for predicting EAs. Comparisons with the analogous C2Fn and Si2Fn systems reveals some interesting trends and differences. For example, while C2F6 will not capture an electron, Si2F6 is predicted to have small electron affinity (0.73 eV), while that of Ge2F6 is substantial. The same trend to larger EAs on going down the Periodic Table is seen for the X2F5 systems, with 1.77 (C2F5), 2.68 (Si2F5), and 4.57 eV (Ge2F5). However, the EAs do not follow a monotonic trend for the X2F, X2F3 and X2F4 systems with respect to the series X = C, Si, Ge.

Journal Article↗

PubMed2002

[Relationship between rare earth accumulation and rape sclerotiniose].

Field plot experiment with long-term application of rare earth fertilizers showed that 0.5-10% of adsorption capactiy and 0.6 kg.hm-2 of rare earth application had no remarkable effect on natural incidence of rape sclerotiniose, ratio of diseased plants, natural disease index, expanding rate of diseased spots, yield of single plant, and 1000-seed weight.

Ascomycota↗