In this paper, a howerful method was introduced to study the metabolism in brain. Adult rats were frozen with liquid-N\-2 through a self-command funnel. A

fter perchloric acid (PCA) extracts were prepared and lyophilized, the residual substance were dissolved in D₂O and investigated with ¹H and ³¹P nuclear magnetic resonance spectroscopy (MRS). Result:High-resolution nuclear magnetic resonance spectroscopy of brain tissue was achieved. ³¹P MRS reveals ATP, ADP, phosphocreatine, inorganic orthophosphate and manifold aliphatic phosphates and sugar phosphates; ¹H MRS shows many resonance peaks, including lactate, N-acetylaspartate, choline, creatine, GABA, myo-inositol, succinate and manifold amino acids. The peaks were integrated and the relative values might be used to express the metabolism or damnification of brain.

Nuclear magnetic resonance spectroscopy (MRS) is a unique scatheless noninvasively method to detect the metabolism of brain in cell level on living body.
³¹P MRS is used to check and measure the content varieties of manifold metabolites in brain.; Purpose:Study of ³¹P MRS in acute hypoxic brain of rat.;
Materials and methods:(1) Twentyl adult male SD rats suffered from hypoxic experiments were divided into four groups -0min(control), 5min,10min,15min. Then the brains were quickly frozen with liquid N\-2 and the whole brains were removed and restored in liquid N\-2. (2) The frozen brains were pulverized to a fine powder with a stainless steel mortar and pestle chilled with liquid N₂. Then perchloric acid (PCA) were added into the tissue powder, and the extract were lyophilized. (3) The extracts were dissolved in 0.5mL D\-2O for MRS analysis.; Results:(1) Hypoxia reduced the densities of high-energy phosphates (ATP, PCr) and increased content of Pi. The ratio of PCr/Pi and ATP/Pi lowered and ADP/ATP raised. In exchangeable phosphate pool(EPP), the normal value of PCr was 42.4%, after 5min hypoxia episode, it decreased to 28.9%, ATP decreased from 33.8% to 19.2%, and Pi increased from 17.7% to 42.0%. (2) Hypoxia increased the content of GPC and GPE, which were metabolites of phospholipid resolved.; Conclusion: ³¹P MRS of PCA extracts suit the study of energy metabolism and phospholipid metabolism of brain. Acute hypoxia lead to some obvious varieties of the spectroscopy, and the notable varieties were PCr/Pi and ATP/Pi. This may be used to diagnose the disease of hypoxia or ischemia.

The relation of rock petrophysical and nuclear magnetic resonance (NMR) properties were investigated systematically on the continental sedimentary rocks existing significantly in China. Methods translating NMR measurement results to petrophysical parameters that conventionally used in petroleum industry were discussed in detail. Differences between conventional core analysis and NMR measurements were compared. Experimental results were compared as well as with some overseas ones according to Chinese sedimentary rock characteristics. Research results are useful in the application of NMR to petroleum industry in China.

In order to reasonably use nitroxides in plant, We compared the stability of several nitroxide compounds in plant. Under the same condition, the compound was lead into plant though soaking in the diluted solution. At different time, the ESR spectra of different parts of plant were measured and the growth

 status of plant were observed. The characters of spin probes, which can exist steadily in plant with high signal and less toxicity are found. Usually they are

derivatives of pyrrolidine with small molecular weight. From the kinetic curves and growth states of the plant, it was found that the concentration of 10^-4 mol/L of spin probe was proper for using. The results are helpful for the development of plant ESR imaging and may be developed to a new method for me

asuring plant physiology.

A photo-induced hydrogen abstraction reaction have been proved in the porphyrin/quinone solution containing protic solvent by means of CIDNP and ESR methods.

The quantitative ¹³C high resolution NMR spectrum of poly(N-isopropylacrylamide) (PNIPAAM) was assigned with the aid of Gaussian98 calculation. Two methods, γ-gauche effect and ab initio calculation, have been applied to calculate the ¹³C NMR chemical shifts of stereosequences of PNIPAAM. The parameters for γ-gaucheeffect were developed from the ab initio calculations of diads. The basis set used was 6-31G*, and the method was GIAO-CHF. For ab initio calculation, all geometries were optimized via AM1 method and the ¹³C NMR chemical shifts were calculated via GIAO-CHF method with STO-3G basis set. Stereosequences to triad level were considered for the methine carbon of main chain, while for the methylene and methyl carbons, stereosequences to tetrad and pentad level were considered respectively. It was found that the ab initio calculation can well reproduce the obse

rved ¹³C NMR spectrum, while the γ-gauche effect method failed to give satisfactory result. Thus, based on the result of ab initio calculation, the signals of m

ethine carbons, methylene carbon and methyl carbon were assigned and the tacticity of PNIPAAM was turn out to be random. As a result, the ab initio calculation was proved to be an effective method to investigate the tacticities of macromolecules.

MCM-22 is a new molecular sieve which is expected to be widely used in chemical industry. In this paper we study the ²⁷Al species of different acid sites in the MCM-22. ²⁷Al spectra of samples rehydrated in differently extent have been acquired. It is difficult to get high resolution ²⁷Al spectrum of the dehydration powder sample directly because of the existence of strong quadrupole interaction which comes from asymmetric local chemical environment. In order to overcome the strong quadrupole interaction of ²⁷Al, the double resonance NMR method ¹H/²⁷Al TRAPDOR is used in this study. Quadrupole coupling constants (QCC) for aluminum species are abtained. By calculation of the second order quandrupole line width of these aluminum species , it can be concluded that 4-, 3-coordinate framework aluminum and extra-framework alumium are all the source of the “NMR invisible aluminum”.

Two new type pseudorotaxanes are formed by novel (-electron-rich aromatic polyethers containing hydroxy and thiohydroxy with cyclobis(paraquatphenylene)tetracationic cyclophane(CPQT) respectively. We use ¹H NMR spectroscopy to study the property of pseudorotaxanes, and found that the pseudorotaxane containing hydroxy is more stable than the pseudorotaxane containing thiohydoxy as a result of ［C-H…OH］hydrogen bonds. Otherwise, we can monitor the pseudorotaxane containing thiohydoxy by Ag⁺⁺.

This paper discussed the structure elucidation of two saponins, Latifoloside I isolated from Ilex latifolia Thunb and Kudinoside K isolated from Ilex

kudincha C. J. Tseng. On the basis of chemical and spectroscopic evidences, mainly modern 2D NMR technique, their structures were determined to be 3-O-β-D-glucopyranosyl-(1→3)-α-L-arabinopyranosyl-30(S)-3,19,23-trihydro-xyurs-12-en-28-oic- acid 28-O-β-D-glucopyranoside and 3-O-［α-L-rhamnopyranosyl-(1→2)］-［β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→3)］-α-L-arabinopyranoyl-3β,19α,20β-trihydr-oxyurs-12-en-28-oic acid 28-O-［α-L-rhamnopyranosyl-(1→2)］-β-D-glucopyranoside, respectively.

The results of ¹H NMR investigation of  β-Cyclodextrin inclusion complexes with three  cyanine dyes in D₂O and DMSO solution are reported in this paper, It was found that there is difference in chemical shift of some protons both of β-Cyclodextrin cavity and of cyanine dyes between after and before complexing,the position of which is dependent upon the inclusive degree. Fluorescence spectroscopy of cyanine dyes showed that the fluorescence intensity of these dyes is obviously quenched due to the forming of inclusions with β-Cyclodextrin, calculation results based on fluorescence spectroscopy indicated that β-Cyclodextrin formed 1∶1 inclusion with three cyanine dyes respectively. Information about hydrogen bond was induced from the study of temperature dependence of chemical shift of hydroxyl protons in β-Cyclodextrin cavity, OH-3 and OH-6. Their equilibrium constants of inclusion complexes were obtained from NMR chemical shift titration. The structure model of three inclusion complexes and dynamic process entering β-Cyclodextrin cavity has been described in this paper.

Systematic studies were made on carbon-13 nuclear magnetic resonance (¹³C NMR) and its regularity of chemical shift (CS).  In the present paper, A novel atomic distance-edge (ADE) vector or ν vector expressed in the form of energy was developed and found to be correlated excellently with  the chemical shift (CSC) for carbon-13 nuclear magnetic resonance (¹³C NMR).  The multiple linear regression (MLR) equations, CSC=aν+ap₃=∑^m_j=0a_jν_j+a₁₀p₃=a₀(ν₀₌₁)+a₁ν₁+a₂ν₂+a₃ν₃+a₄ν₄+bP₃, of atomic modelling were established by the atomic distance-edge vector together with the path count of three bonding segment (C-C-C) It gives very good results  for the modelled estimation and quantitative prediction with cross validation (CV) of leave-one-out (LOO) procedure.

Hyperfine structure spectra for 4f⁴5d⁺⁶K_9/2→(23229.991)^o_9/2} transition in ^143,145Nd⁺ were measured by using collinear fast-ion-beam laser spectroscopy, and the magnetic dipole and electric quadrupole coupling constants of the metastable levels and excited levels were determined.