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F L Liao

Publications and source records attributed to F L Liao.

11 recordsLinked to original sources
PubMed2001

A linear cyclic oximate-bridged tetracopper(II) complex.

The crystal structure of the title complex, tetrakis[mu-6-amino-3-methyl-4-azahex-3-en-2-one oximato(1-)-kappa4N,N',N":O]tetracopper(II) tetraperchlorate 0.6-hydrate, [Cu4(C6H12N3O)4](ClO4)4*0.6H2O, shows the cation to be an oximate-bridged tetramer composed of four 6-amino-3-methyl-4-azahex-3-en-2-one oxime ligands and four copper(II) ions and to have crystallographically imposed 4 symmetry. Each Cu(II) atom is four-coordinated by the three N atoms of one oxime ligand and by the O atom of another oxime ligand in a distorted square-planar geometry.

Journal Article↗
PubMed2001

(Nitro-kappaN)[2-(phenyldiazenyl-kappaN2)-pyridine-kappaN](2,2':6',2''-terpyridine-kappa3N)ruthenium(II) tetrafluoroborate.

The Ru-N bond distances in the title complex, [Ru(NO(2))(C(11)H(9)N(3))(C(15)H(11)N(3))]BF(4) or [Ru(NO(2))(tpy)(azpy)]BF(4), [tpy is 2,2':6',2"-terpyridine and azpy is 2-(phenylazo)pyridine], are Ru-N(py) 2.063 (4), Ru-N(azo) 2.036 (4), Ru-N(nitro) 2.066 (3) A, and Ru-N(tpy) 2.082 (4), 1.982 (3) and 2.074 (4) A. The azo N atom is trans to the nitro group. The azo N=N bond length is 1.265 (5) A, which is the shortest found in such complexes to date. This indicates a multiple bond between Ru and the N atom of the nitro group, and pi-backbonding [dpi(Ru) --> pi*(azo)] is decreased.

Journal Article↗
PubMed2000

Crystal and molecular structure of an eight-coodinate N-methyltetraphenylporphyrin complex: diacetato(N-methyl-meso-tetraphenylporphyrinato)thallium(III).

The crystal structure of diacetato(N-methyl-meso-tetraphenylporphyrinato)thallium(III), Tl(N-Me-tpp)(OAc)2 (1), was established, and the coordination sphere around the Tl3+ ion is described as an eight-coordinate square-based antiprism in which two cis chelating bidentate OAc- groups occupy two apical sites. The plane of the three pyrrole nitrogen atoms (i.e., N(1), N(3), N(4)) strongly bonded to Tl3+ is adopted as a reference plane 3N. The pyrrole N(2) ring bearing the methyl group (i.e., C(45)H3) is the most deviated one from the 3N plane, making a dihedral angle of 21.4 degrees, whereas smaller angles of 9.1 degrees, 7.1 degrees, and 0.9 degree occur with pyrroles N(1), N(3), and N(4), respectively. Because of its larger size, the thallium(III) ion Tl3+ is considerably out of the 3N plane; its displacement of 1.17 A is in the same direction as that of the two apical OAc- ligands. The intermolecular acetate exchange process for 1 in THF-d8 solvent is examined through 1H NMR temperature-dependent measurements. In the slow-exchange region, the methyl and carbonyl carbons of the OAc- groups in 1 are separately located at delta 18.6 [3J(Tl-13C) = 405 Hz] and 170.8 [2J(Tl-13C) = 334 Hz] at -80 degrees C, respectively.

Journal Article↗
PubMed1998

Newly developed initial-flow cell filtrometer and the comparison with viscometry and ektacytometry on erythrocyte deformability.

According to Hanss's initial-flow rate method, F. Liao designed a new cell filtrometer in the early 1990s. The parameters, cell initial transit time (Tc) and membrane clogging rate (CR), can be determined by a single measurement with timing accuracy of 1 ms. The new cell filtrometer has two valuable features: a button-pushing operation to control electromagnetic valves; and an autocirculation of fluid in the cell filtrometer resulting in the same volume of leading fluid. A series of comparisons of the new filtrometry with viscometry or ektacytometry shows that the instrument seems to be more sensitive in detecting subpopulations of glutaraldehyde-hardened cells and the shift of deformability for all the cells. The reproducibility of the filtrometer for different membranes made in China and the USA is reasonable (CV < 5% for Tc). Preliminary application of the filtrometer indicates that it might be useful for trial study and routine clinical application.

Animals↗
PubMed1998

A new simple cone-plate viscometer for hemorheology.

The aim of this work was to evaluate a new automatic cone-plate viscometer (LBY-N6, PRECIL, Beijing, China) which was designed for clinical measurements of blood and plasma viscosities. Standard calibrating oils of viscosity varying from 1.85 to 20.5 mPas (conforming to ASTM Standard) were used to test the precision and reproducibility of the device. Then the viscometer was used to measure blood and plasma viscosities. The results were compared with those obtained with a conventional Couette viscometer and a capillary viscometer. The results showed that this new viscometer gave good values of viscosity for standard oils with relative errors lower than 10% at shear rates ranging from 20 to 200 s(-1). It also had a good reproducibility (standard deviations < 3% in most cases). Only the results at low shear rates (< 10 s(-1)) were less identical. As for blood, the relative difference between the results given by LBY-N6 and those obtained by Low Shear 30 was less than 10% at high shear rates. This difference decreased with shear rate and could be partly caused by viscoelastic and thixotropic properties of human blood. A small difference between the values of plasma viscosity obtained by LBY-N6 and the capillary viscometer AMTEC was also observed. In conclusion, this new viscometer can be used a routine tool to determine quickly plasma and blood viscosities in clinical practice at shear rates higher than 20 s(-1).

Blood Viscosity↗
PubMed1983

Effect of microrheology of blood on the apparent flow instability in a rotational viscometer.

Flow instability (formation of vortices and a concurrent increase in the apparent viscosity) was studied in the rotational rhombospheroid viscometer of 3 degrees, 5 degrees and 10 degrees gaps over a range of speeds from 10 to 300 r.p.m.. Comparisons between different blood systems were carried out mainly at 250 r.p.m. Experiments were carried out on blood samples obtained directly from human subjects, or from the Blood Bank, or from horses. Reconstituted suspensions of red cells in albumin or dextran were also used. Apparent flow instability was found to be not solely a function of blood viscosity, but a multiple function of many viscosity factors or blood subphases, including instability-decreasing factors such as haematocrit and aggregation of red cells; and instability-increasing factors such as rigidity of red cells; and thus specific to and characteristic of individual blood samples. Apparent instability can be described by multiple regressions as a function, Z, of red cell rigidity, Tk, blood viscosity, napp, and aggregation of red cells, AG; for example: Z = -28.29 + 26.24 Tk + 0.109 napp (r = 0.816; P less than 0.001), or Z = 5.90 - 0.0165 AG - 0.752 napp (r = 0.573; P less than 0.05). The apparent instability can be seen only in one-third of blood samples obtained from horses, and in more than half of blood samples obtained from human donors; majority of human donors shows apparent instability below 3 per cent.

Animals↗
PubMedDate not supplied

Inhibition of shear-induced platelet aggregation by Chinese herbal medicines.

Shear-induced platelet aggregation (SIPA) plays an important role in vascular diseases. In this study, SIPA was generated by a computerized cone-plate apparatus. Six compounds from Chinese herbal medicine were selected for in vitro and in vivo tests. Rabbit and rat were involved in the tests accordingly. Ligustrazine hydrochloridi appeared to be most effective for inhibition of SIPA. The inhibition rate of SIPA reached 44.2% (p < 0.01) for an in vitro concentration of 1 mg/ml, and 46.1% (p < 0.01) for an in vivo dose of 50 mg/kg.

Animals↗