Biomedical subjects
Publications and source records attributed to S D Huang.
The metal atom in the title complex, [CoCl2(C8H8N2)2], has a slightly distorted tetrahedral coordination involving two Cl- ions and two N atoms from the aromatic groups. The dihedral angle between the planes of the two 1-methylbenzimidazole ligands is 117.7 (7) degrees.
Potassium sodium metavanadate, KNa(VO3)2, crystallizes with the pyroxene structure and is made up of VO4 tetrahedral chains, NaO6 octahedra and KO8 dodecahedra. The chains of corner-sharing VO4 tetrahedra are crosslinked through the NaO6 octahedra and KO8 dodecahedra to form a three-dimensional structure with the K+ and Na+ cations, which lie on twofold axes, situated in the void space. The coordination around the Na+ ion is close to normal octahedral, while the O atoms coordinated to the K+ ion are arranged approximately in a dodecahedral fashion.
The title compound, ethylenediammonium hexaaquacobalt bis(hydrogenphosphate), consists of [Co(H2O)6]2+ and [enH2]2+ cations (en is ethylenediamine), and [HPO4]2- anions interconnected by an extensive intermolecular three-dimensional hydrogen-bonding network. The [enH2]2+ cations play an important role in the templating effect. Both [Co(H2O)6]2+ cations are situated on inversion centers. The average Co-O and P-O bond distances are 2.075 (6) and 1.54 (2) A, respectively.
Solid-phase microextraction (SPME) coupled with high-performance liquid chromatography (HPLC) for the analysis of hydroxyaromatic compounds is described. Three kinds of fibers [50 microns carbowax-templated resin (CW-TPR), 60 microns polydimethylsiloxane-divinylbenzene (PDMS-DVB) and 85 microns polyacrylate (PA) fibers] were evaluated. CW-TPR and PDMS-DVB were selected for further study. The parameters of the desorption procedure (such as desorption mode, the composition of the solvent for desorption and the duration of fiber soaking) were studied and optimized. The effect of the structure and physical properties of analytes, carryover, duration of absorption, temperature of absorption, pH and ionic strength of samples were also investigated. The method was applied to environmental samples (lake water) using a simple calibration curve.
A chemical study of the sea feather Pseudopterogorgia bipinnata from Colombia has produced four known metabolites, namely, kallolide A (1), bipinnatin A (2), bipinnatin C (3), and bipinnatin J (4), in addition to nine previously undescribed diterpenes possessing an uncommonly high level of oxygenation. One of them, bipinnapterolide A (5), is a new representative of the pseudopterane family of diterpenes possessing the rare 2,3-epoxy-1,4-dione moiety. The other metabolites, bipinnatins G-I (6-8) and bipinnatolides F-J (9-13), are highly oxygenated cembranolide diterpenes. Their chemical structures including relative stereochemistry were established by detailed analysis of the spectral data in addition to X-ray diffraction analysis and NMR spectral comparisons with known pseudopterane and cembranolide models.
Crystals of the title compound, octaammonium dicerium octasulfate tetrahydrate, suitable for X-ray work, were prepared by a hydrothermal reaction. The structure is made up of [Ce2(SO4)8]8- anions, interacting with the crystallization waters and the NH4+ cations through hydrogen bonds. The CeIV atom in the [Ce2(SO4)8]8- anion is ninefold coordinated by O atoms belonging to sulfate groups. The coordination polyhedron is a somewhat distorted tricapped trigonal prism. The Ce-O distances range from 2.325(2) to 2.478(2) A.
The title compound, C7H20BNOSi, features an N,N-disubstituted six-membered morpholine ring in a chair conformation, with the trimethylsilyl group in the equatorial position and the borane group in the axial position. The least-squares plane formed by the four C atoms of the morpholine ring has a mean deviation of 0.013 (2) A. The O and N atoms are 0.672 (2) and 0.650 (2) A above and below the plane, respectively.
The molecular structure of the title compound, C16H16BrNO3, consists of 2-bromo-4,5-dimethoxy-benzene and o-methylphenyl rings linked by an amide group. The two methoxy groups are almost coplanar with the phenyl ring.
The title compound, C15H9Br2CIN2O2S, was synthesized by electrophilic addition of bromine to 2-(2-chloro-5-nitrostyryl)benzothiazole. The molecule consists of benzothiazole and 2-chloro-5-nitrophenyl rings linked by a 1,2-dibromoethane moiety. The dihedral angle between the benzothiazole and phenyl rings is 8.2(9) degrees. The benzothiazole ring is planar with a mean deviation of 0.168(7)A. The Br1--C8 and Br2--C9 bond distances are 1.972(5) and 2.007(6)A, respectively.
The title compound, C16H20O5, was isolated from the gorgonian coral P. americana found in the Caribbean zone of the West Indies. The compound belongs to a well known family of sesquiterpenoid lactones. Its structure features a guaiane skeleton incorporating three types of oxygen functionalities. Thus, the five O atoms that are incorporated in the skeleton form two epoxy groups, a lactone moiety and an ether link. This study assigns the relative stereochemistry at the six chiral centers as 1R, 2R, 4S, 5S, 8R, 10S.
The title compound, C18H14ClN3O2, was synthesized by the condensation of 2-chloro-5-nitrobenzaldehyde with 2-methyl-1-propenylbenzimidazole, and the molecule comprises a 2-chloro-5-nitrobenzene and a 1-(Z)-propenylbenzimidazole. The two aromatic moieties are conjugated through the vinyl group. The dihedral angle between the two rings is 1.4(6) degrees. The propenyl group lies out of the benzimidazole plane with a dihedral angle of 112.9(9) degrees.
The title compound, C15H9BrN2O3S, was isolated as an unexpected product from the reaction of the anion of sodium 2-(1,3-benzothiazolyl)ethanonitrile with alpha,2-dibromo-5-nitrotoluene. Its structure features a benzothiazole fragment and a bromo- and nitro-substituted phenyl ring linked by a methyl ketone group. The dihedral angle between the benzothiazole and phenyl rings is 103.7 (2) degrees. The benzothiazole fragment is planar, with a maximum deviation of 0.021 (2) A. The nitro group is slightly rotated out of the phenyl-ring plane, with a O(2)-N(2)-C(14)-C(15) torsion angle of 16.4(7) degrees.
Euniciniatin [4(S),7(R)-epoxy-3(R)-hydroxy-1(R),11(S) -dolabella-8(Z),12(18)-dien-13-one; (1R,3R,4S,7R,11S) -3-hydroxy-12-isopropylidene-15-oxa-1,4,8-trimethyltricyclo [9.3.0.1(4,7)]pentadec-8(Z)-3n-13-one], C20H30O3, was synthesized from a known dolabellane constituent of E. laciniata, namely, dolabellatrienone. The structure of this compound has a trans-bicyclo[9.3.0]tetradecane nucleus containing an additional 4,7-oxa bridge. The three O atoms in the molecule all belong to different functional groups, i.e. one is part of an ether bridge [O(3)-C(4) 1.452 (5) and O(3)-C(7) 1.429 (5) A], one an alcohol [O(2)-C(3) 1.429 (6) A] and one a ketone [O(1)-C(13) 1.233 (5) A].
The title compound, bis[(E)-2-(2,4-dichloro-5-nitrostyryl)-1,3-benzothiazole] hydrate, 2C15H8Cl2N2O2S.-H2O, was obtained from the condensation of 2-methyl-benzothiazole with 2,4-dichloro-5-nitrobenzaldehyde. Single-crystal X-ray analysis showed that the asymmetric unit contains two crystallographically unique but structurally similar molecules. The dihedral angle between the benzothiazole fragment and the phenyl ring is 6.1 (4) degrees in molecule A and 19.5 (4) degrees in molecule B.
Ankle arthrodesis is still the treatment of choice for most disabling arthritic ankles. But in spite of its popularity, ankle arthrodesis has many disadvantages, including long immobilization, a high pseudoarthrosis rate, and load shift with increased stress on neighboring joints of ankle. Lower tibial osteotomy is one of the methods which attempts to halt ankle arthritis in the intermediate stage and trying to prevent ankle arthroadesis. From Aug. 1989, we performed 8 operations of lower tibial osteotomy in our hospital on intermediate arthritic ankle which included 4 post-traumatic ankle arthritis and 4 ankle osteoarthritis. The patient's ages ranged from 21y/o to 72y/o with an average of 41.6y/o. The mean time of followed up was 31.7 months. The patients were evaluated by the ankle functional scale preoperatively and during their followed up. The average preoperative functional score was 49.6 and the last follow up score was 88.5 which is increasing year by year. Significant improvement occurred in function and pain relief and there was improvement of ankle motion in most patients except one. Complications included late infection in 1 patient and implant failure with subsequent revision surgery due to overcorrection in 1 patient. No nonunion was noted. Although our series was small, we had encouraging short-term results. We believe lower tibial osteotomy, by pressure redistribution on the joint surface, is an alternative for the treatment of ankle osteoarthritis and may save or delay arthritic ankle from the fate of fusion.
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