Radioimmunoassay for the determination of 2-methoxyestriol concentration in plasma of pregnant women.

A specific assay method has been developed for the determination of 2-methoxyestriol in plasma of pregnant women. The quantitation was achieved by radioimmunoassay after extraction of the plasma with ethyl acetate and purification on a Sephadex LH-20 column. In order to obtain the immunogen for 2-methoxyestriol, 6-oxo-2-methoxyestriol was converted to its 6-(O-carboxymethyl)oxime derivative. The derivative was then coupled to bovine serum albumin by the mixed anhydride method, and rabbits were immunized with this conjugate. The antiserum obtained was partially purified by affinity chromatography on estrone 17-(O-carboxymethyl)oxime-aminohexyl Sepharose conjugate to eliminate the cross-reactive antibodies. Plasma 2-methoxyestriol concentrations in pregnancy were estimated to be mean values of 41.1 pg/ml (12th-14th week), 85.3 pg/ml (27th-29th week), and 97.5 pg/ml (37th-41st week).     

Top-gathering pillar array of hybrid organic–inorganic material by means of self-organization

Two-dimensional (2D) pillar arrays with submicrometer to micrometer repetitions have been fabricated from hybrid organic–inorganic material by mask lithography or multi-beam interference lithography. The type of array structure depends on structural parameters such as the pillar height, diameter and distance between neighboring pillars. Two kinds of periodic arrays, 2D arrays and ‘top-gathering’ arrays, can be obtained by controlling the structural parameters. In the top-gathering arrays, the pillars are gathered at the top by means of self-organization, and ‘top-gathering’ units composed of four pillars can be formed. PACS 68.35.Gy; 81.20.Fw; 82.50.-m     

Synthesis,Properties, and π‐Dimer Formation of Oligothiophenes Partially Bearing Orthogonally Fused Fluorene Units

A series of oligothiophenes that incorporate cyclopenta[c]thiophene‐based units bearing spiro‐substituted dialkylfluorene was synthesized. Photophysical measurements indicated that there was no interruption in the conjugation along the oligothiophene backbones, irrespective of the number or position of this unit. Electrochemical measurements showed that the thiophene 7‐mers and 11‐mer exhibit reversible multi‐oxidation waves. The formation of cationic species was clearly observed from UV/Vis/NIR measurements. Furthermore, the UV/Vis/NIR spectra at 223 K under one‐electron oxidation conditions revealed that the unsubstituted thiophene or bithiophene units remained in the absence of intermolecular π–π interactions, whereas the formation of π‐dimeric species was observed for the thiophene 7‐mer containing an unsubstituted terthiophene ( U₃ ) unit. Theoretical calculations indicated that the combination of the U₃ unit and the all‐trans conformation decreased the intermolecular steric repulsion between the fused cyclopentene ring and its facing thiophene, which may contribute to the formation of the dimeric structure.     

Liquid single- and gas—liquid two-phase flows of magnetic fluid in the presence of a high non-uniform parallel magnetic field

The effect of a non-uniform parallel high magnetic field on flow control characteristics is investigated experimentally for a magnetic fluid single-phase flow and an air—magnetic fluid two-phase flow in a vertical channel. It is found that as the magnetic field strength is increased, the friction factor of the single-phase flow increases significantly. For the two-phase flow, the friction pressure loss and the head pressure loss, which is smaller than the friction loss, are negligibly small compared with the magnetic pressure loss. In the case where air is injected 27.9d upstream from the maximum magnetic field, the air flow is blocked by the magnetic force in the entrance of the magnetic field, which leads to increases in both local void fraction and pressure drop there. In the case where air is injected 1.43d downstream from the maximum magnetic field, the air flow is accelerated, resulting in a decrease in void fraction and an increase in pressure rise. In the latter case and under the present range of experimental conditions, the magnetic pumping head reaches 0.02 MPa at the highest, and the maximum circulation flow rate reaches twice as high as non-magnetically driven flow rate.     

Quinolone Analogs 14: Synthesis of Antimalarial 1‐Aryl‐3‐(4‐quinolon‐2‐yl)ureas and Related Compounds

The 4‐quinolone‐2‐carbohydrazide 6a was converted into 1‐aryl‐3‐(4‐quinolon‐2‐yl)ureas 5a , 5b , 5c , 5d , 5e , 1‐aryl‐3‐(4‐quinolon‐2‐yl)imidazolidine‐2,4‐diones 9a , 9b , and N‐(4‐quinolon‐2‐yl)carbamates 10a , 10b via 4‐quinolone‐2‐carbonylazide 7a . The 4‐methoxyquinoline‐2‐carbohydrazide 6b was also transformed into 1‐aryl‐3‐(4‐methoxyquinolin‐2‐yl)ureas 11a , 11b , 11c , 11d , 1‐aryl‐3‐(4‐methoxyquinolin‐2‐yl)imidazolidine‐2,4‐diones 12a , 12b , and N‐(4‐methoxyquinolin‐2‐yl)carbamates 13a , 13b via 4‐methoxyquinoline‐2‐carbonylazide 7b . Some of the 1‐aryl‐3‐(4‐quinolon‐2‐yl)ureas 5a , 5b , 5c , 5d , 5e showed the in vitro antimalarial activity to chloroquine‐resistant Plasmodium falciparum, wherein IC₅₀ was 0.93 to 4.00 μM.     

Tigloylshikonin, a new minor Shikonin derivative, from the roots and the commercial root extract of lithospermum erythrorhizon

Tigloylshikonin, a new shikonin derivative esterified with tiglic acid ((E)-2-methylbut-2-enoic acid), was isolated as a minor pigment from a food colorant "Shikon color," a commercial root extract from Lithospermum erythrorhizon SIEBOLD et ZUCCARINI. The structure of tigloylshikonin was elucidated using (1)H, (13)C, the difference nuclear Overhauser effect (NOE), and 2D NMR techniques. Its stereochemistry was determined by chiral-phase HPLC analysis. Tigloylshikonin was also found in the roots of L. erythrorhizon, which indicated that this new shikonin derivative is a typical component of naphthoquinone pigments in the roots of L. erythrorhizon.     

Adsorption of several gases on flexible metal organic framework [Cu(dhbc)2(4,4'-bpy)]·H2O

The adsorption of ten gases on the flexible metal organic framework material [Cu(dhbc)(2)(4,4'-bpy)]·H(2)O (Cu(db)) has been measured over a wide range of temperatures and pressures. The gate opening condition and driving force behind gate adsorption for Cu(db) were discussed by examining the adsorption isotherms. The adsorption isotherms for each adsorbate can be generalized to a characteristic curve using the adsorption potential energy (ε) and the adsorption volume. The adsorption potential (ε(gate)) at gate opening is almost constant over a wide range of temperatures; thus, the gate pressure at a desired temperature can be deduced using the ε(gate) evaluated from one adsorption isotherm. The gate opening capacity of the gases was arranged in the order: CO(2)≒N(2)O>C(2)H(4)≒Xe>CH(4)>CO>O(2)>Ar≒N(2)>H(2), which is governed by the interaction energy between the outer surface of Cu(db) and the adsorbate. It is suggested that the gate effect is brought about when the integral interaction energy of adsorbates with the Cu(db) surface exceeds a defined limit correlating with the π-π stacking energy of Cu(db) layers.     

Application of Mitsunobu reagents to redox isomerization of CF3-containing propargylic alcohols to (E)-α,β-enones

Isomerization of CF(3)-containing secondary propargylic alcohols proceeds with excellent E selectivity by treatment with Mitsunobu reagents, tris(p-methoxyphenyl)phosphine (TMPP), and 1,1'-(azodicarbonyl)dipiperidine (ADDP) in the presence of phenol.