A CIRCULAR DICHROIC STUDY OF THE INTERACTION OF INSULIN A AND B CHAINS

It has been shown previously that the S-thiomethyl forms of the insulin A and B chains interact in solution leading to a partial transfer of Tyr side chains from hydrophilic to hydrophobic environments. In the present work, a circular dichroic study has indicated that the α-helix contents of the chains show a gradual increase upon mixing of the chains reaching completion in about 2h. The separated S-thiomethyl protected chains contain some ordered structure (A: α=15%, β=27%: B: α=22%, β=23%). Contrary to reports in the literature, the reduced chains also show some ordered structure and upon mixing of the reduced chains, the α-helix content also shows some increase. The ordered structure of the reduced chains decrease with increasing concentrations of dithiothreitel and in presence of a large excess of DTT both the reduced chains have very little, if any, α-helix structure. These latter results are in accord with those of Wu and Yang. In agreement with the results obtained previously with ultravio     

A STUDY OF THE INTERACTION AND FORMATION CONSTANTS OF NAPHTHALENE DERIVATIVES WITH CYCLODEXTRIN BY FLUORESCENCE AND CIRCULAR DICHROISM SPECTRA

The molecular recognition of the α,β-CD and 6~A,6~(C(D))-o,o′-(4,4′-diphenyloxide-disulfonyl)-β-CD to naphthalene derivatives was studied by fluorescence and circulardichroism spectra.The formation constants of the inclusion complexes were estimatedbased on the variation of fluorescent intensity and the modified Benesi-Hildebrand equa-tions.     

NMR AND INFRARED SPECTROSCOPIC STUDY ON THE INTERACTION OF RARE EARTH WITH L-METHIONIHE

Five solid complexes of rare earth with L-methionine have been prepared. The interaction of rare earth with the ligand has been studied by NMR and IR spectroscopy.     

A CIDNP STUDY OF THE PHOTOREACTIONS OF METHYLFURANS WITH CHLORANIL

The CIDNP observations indicated that photoreaction of methylfurans with chloranilresulted not only furylmethyl hydroxyphenyl ethers via radical pairs but inducedfuryl radical isomerization to the derivatives of cyclopropene,propadiene and pyran.     

A STUDY OF THE REACTIONS OF BENZYL ETHERS WITH DIBROMOCARBENE

Using potassium carbonate as base and a polyethylene glycol with an average molecular weight of 600 (PGE600) as phase transfer catalyst, reaction of benzyl ethers with dibromocarbene leads to benzylic C—H bond insertion products, aromatic aldehydes are also formed as one of the products.     

VIBRATIONAL SPECTROSCOPIC STUDY OF THE INTERACTION BETWEEN Ge-132 AND DIPALMITOYLPHOSPHATIDYLCHOL INE

The vibrational spectra of both pure DPPC liposomes and DPPC multilayers reconstituted with Ge-132are reported as a function of temperature from 290 to 330K.The results show that the addition of Ge-132results in suppression of the pretransition behavior and reduction of temperature of the main transition forreconstituted system.The results also show that the degree of rigidity of the acyl chain in the presence ofGe-132 is lower than that in pure DPPC dispersion within the investigated temperature range.     

NMR STUDIES ON THE WEAK INTERACTION OF FOUR-MONONUCLEOTIDES WITH TRYPTAMIDE AND LEUCINAMIDE

NMR spectroscopy analysis was introduced to investigate the weak interaction of four 5'—mononucleotides with tryptamide and leucinamide. Assuming a 1∶1 complex formation, the association constants were determined by nonlinear regression analysis. The association affinity of 4 mononucleotides with tryptamide decreased in the order: G>A>C>U, indicating that purine bases stack more strongly with tryptamide than pyrimidine bases. But with leucinamide the affinity decreases in the order: G>C>A=U, suggesting an amino acid—anticodonic preferential interaction. The implication of the present data to the origin of genetic code was briefly discussed.     

THE STUDY ON TRE KINETICS AND MECHANISM OF THE REACTIONS OF METAL IONS WITH PnAO

The kinetics and the mechanism of the formation reactions ofM(PnAO)~(2+)(M=Ni,Co,Cu)were studied with UV Spectrophotometer and StoppedFlow Spectrophotometer and a three steps mechanism was suggested.     

INVESTIGATION ON THE INTERACTION OF METHANE WITH MgO SURFACE BY FT－IR SPECTROSCOPY

ＩＮＶＥＳＴＩＧＡＴＩＯＮ　ＯＮ　ＴＨＥ　ＩＮＴＥＲＡＣＴＩＯＮ　ＯＦ　ＭＥＴＨＡＮＥ　ＷＩＴＨ　ＭｇＯ　ＳＵＲＦＡＣＥ　ＢＹ　ＦＴ－ＩＲ　ＳＰＥＣＴＲＯＳＣＯＰＹＣｈｅｎ，Ｌａｉ－ｙｕａｎ；Ｌｉｎ，Ｌｉ－ｗｕ；Ｘｉｎ，Ｑｉｎ；Ｙｉｎｇ，Ｐｉｎ－ｌｉ...     

A STUDY OF THE EFFECT OF ANTAGONISTIC ELEMENTS OF SELENIUM WITH GRAPHICAL AND COMPUTER BASED STATISTIC PATTERN RECOGNITION

THE antagonistic effect is important in the research on bio-trace elements,the practical aspects and an understanding ofthe mechanism of which depend on a knowledge of this effect.In this paper,the data of the per-capita intake of Seand Se-antagonistic elements (Zn,Cd,Cu,Cr,Mn,As) in 27countries and areas and the age-correlated mortalities fromcancer of the breast were treated with the graphical and com-puter based statistic pattern recognition method.The 22equations derived from computer programs of linear regressionanalysis show that a multidimensional space can be reduced toa two-dimensional one.Then the two-dimensional figures wereobtained and they illustrate some empirical rules from whichinformation on the degree and area of the antagonistic effectis obtained.The calculation results of breast mortalitiescoincide with those of the U.S.female breast observed valueand the Keshan disease in China.     

HREELS STUDY OF O_2 AND CH_3OH ADSORPTION ON NIOBIUM（110）

ＨＲＥＥＬＳＳＴＵＤＹＯＦＯ２ＡＮＤＣＨ３ＯＨＡＤＳＯＲＰＴＩＯＮＯＮＮＩＯＢＩＵＭ（１１０）＊ＷａｎｇＹｉｎｓｈｅｎｇ，ＷｅｉＸｕｍｉｎｇ，ＴｉａｎＺｈｉｊｉａｎ，ＺｈａｉＲｕｎｓｈｅｎｇ＊＊（ＳｔａｔｅＫｅｙＬａｂｏｒａｔｏｒｙｏｆＣａｔａｌｙｓ...     

STUDIES ON THE NON－ISOTHERMAL KINETICS OF THERMAL DECOMPOSITIONS OF THE COMPLEXES OF Cd（II）WITH O－VANILLIN THIOSEMICARBAZONE AND IRON（III）WITH 2－［（O－HYDROXYBENZYLIDENE）AMINO］PHENOL AND PYRIDINE

ＳＴＵＤＩＥＳＯＮＴＨＥＮＯＮ－ＩＳＯＴＨＥＲＭＡＬＫＩＮＥＴＩＣＳＯＦＴＨＥＲＭＡＬＤＥＣＯＭＰＯＳＩＴＩＯＮＳＯＦＴＨＥＣＯＭＰＬＥＸＥＳＯＦＣｄ（ＩＩ）ＷＩＴＨＯ－ＶＡＮＩＬＬＩＮＴＨＩＯＳＥＭＩＣＡＲＢＡＺＯＮＥＡＮＤＩＲＯＮ（ＩＩＩ）ＷＩＴ...     

A STUDY OF THE WAVE FUNCTION WITH SYMPLECTIC SYMMETRY~1

By using the linear combination of the AGP(antisymmetrtzed geminat power) and SPG(sequential product of geminats) functions, an attempt has been made to catcutate the ground state of the LiH molecule. The calculated results show that-the AGP or SPG function gives the same ground state result as their linear combination.     

THE CRYSTALLOGRAPHIC STRUCTURE OF THE PHOTOOXIDIZED PRODUCT OF HYPOCRELLIN A AND THE STUDY OF THE PHOTODYNAMIC ACTION MECHANISM

In attempting to study the phototherapeutic action and the photosensitized oxygenation mechanism, we have determined the crystal structure of the main oxidized product of hypocrellin A (HA). It was crystallized in monoclinic system with space group P2_1. The cell data are: a=10.030(3), b=8.877(3), c=15.764(5), β=104.50(2)°, Z=2. The crystal structure has been determined by direct method and refined to a final R of 0.055 based on the 1408 observed reflections with l>2.5σ(Ⅰ). The photooxidized product is composed of a heptacyclic aliphatic hydrocarbon connecting with two α-naphthoquinone derivatives as its skeletal molecule. No peroxidic linkage has been found. On the basis of the crystal structure determined, we have deduced part of the process of formation of the oxide, ⅰ. e. firstly, the peroxide was formed by photocycloaddition of oxygen molecule to Hypocrellin A, then thermodissociation took place to form a stable oxide.     

THE STUDY OF THE SYNTHESES OF THE DERIVATIVES OF POLYPHENYLENE AND THEIR CONDUCTIVITY

ＴＨＥＳＴＵＤＹＯＦＴＨＥＳＹＮＴＨＥＳＥＳＯＦＴＨＥＤＥＲＩＶＡＴＩＶＥＳＯＦＰＯＬＹＰＨＥＮＹＬＥＮＥＡＮＤＴＨＥＩＲＣＯＮＤＵＣＴＩＶＩＴＹ￥ＹｉｎＫｕｉＬｌ；ＱｉｎｇＺｉＬＩＵ；ＳａｎＨＵＡＮＧ；ＴｉｅＦｅｎｇＷＥＮ；ＳｈａｎｇＹｏｕＺＨＯＵ...     

THE ORIGIN OF BIOLOGICAL CHIRALITY AND WEAK INTERACTION

Interaction between polarized electrons and chiral molecules is discussed. It is proved that the direct scattering is the dominant one for producing of the asymmetry of cross sections by comparing with other contributions. The left-right asymmetry of chemical reaction rate induced by inelastic transition of chiral molecules and other related problems concerning the origin of biochirality are discussed.     

STUDY ON PHOTO-INDUCED ORIENTATION OF A NOVEL PHOTO-ALIGNMENT FILM WITH SURFACE ENHANCED RAMAN SCATTERING （SERS） SPECTROSCOPY

Surface enhanced Raman scattering (SERS) spectroscopy was first utilized to study the photo-orientation behaviour of the photoreactive groups on a novel photo-alignment film surface and elucidate the generation mechanism of pretilt angle. The novel photo-alignment film was prepared by spin-coating a solution of ladderlike polysiloxane (LPS) bearing dual photoreactive group on an ITO surface and by irradiation with linear-polarized ultraviolet (LPUV) light. A Si-H terminal compound (M) containing an identical photosensitive part has been used to fabricate a model film for SERS investigation.     

STUDY ON THE INTERACTION OF Se AND ERYTHROCYTE MEMBRANE——PROTECTIVE EFFECT OF Se ON THE ERYTHROCYTE MEMBRANES

During the ageing of erythrocyte membrane, the spectrin content, Na, K-ATPase activity as well as the lipid fluidity are obviously decreased. However, supplementation of a trace amount of Na_2SeO_3 in the medium could prevent the dissociation of spectrin from membrane and delay the changes of Na, K-ATPase activity and lipid fluidity. The effectiveness is proportional to Se concentration within the range of 0.1—1.0 ppm.Similar effect of supplementation of Se on the intact erythrocytes during ageing has been also observed.The protective action of Se on biomembranes is generally interpreted in terms of the activity of Se-containing glutathione peroxidase (GSHPx). However, GSHPx mainly distributes in the cytoplasma of erythrocytes, therefore it seems that the protective action of supplemented Se on the isolated erythrocyte membrane might not be related to the activity of GSHPx.     

AB INITIO CONFIGURATION INTERACTION STUDY OF THE ELECTRONIC AND GEOMETRIC STRUCTURE OF MIXED NEUTRAL AND CATIONIC BLi_k（k＝1~7）CLUSTERS

ＡＢＩＮＩＴＩＯＣＯＮＦＩＧＵＲＡＴＩＯＮＩＮＴＥＲＡＣＴＩＯＮＳＴＵＤＹＯＦＴＨＥＥＬＥＣＴＲＯＮＩＣＡＮＤＧＥＯＭＥＴＲＩＣＳＴＲＵＣＴＵＲＥＯＦＭＩＸＥＤＮＥＵＴＲＡＬＡＮＤＣＡＴＩＯＮＩＣＢＬｉ_ｋ（ｋ＝１~７）ＣＬＵＳＴＥＲＳＨｕａＢｅｉＺＨ...     

A STUDY OF THE GLUCOCORTICOID RECEPTOR OF THE CYTOSOL AND NUCLEI IN NONLETHALLY AND LETHALLY SCALDED RATS

The glucocorticoid receptor (GCR) of the cytosol of liver and brain was studied by radioligand binding assay, using [~3H] dexamethasone (Dex) as the ligand in lethally and nonlethally scalded rats. As compared with controls, the binding capacity (R_0) was decreased and the apparent K_d of [~3H] Dex specific binding was increased in both scalded groups. In the lethal group, the R_u is much lower than that in the nonlethal group. In order to determine whether the decrease of R_0 was due to the translocation of [~3H] Dex-GCR complex into the cell nuclei, the [~3H] corticosterone (B) specific binding of the hepatic nuclei was measured by the exchange assay. There was no significant difference between the control and scalded groups. The possible mechanisms and the clinical significance of these changes were discussed.