Exciton diffusion in solid solutions of luminescent lanthanide ß-diketonates.

In this article, a series of luminescent lanthanide ß-diketonate solid solutions, with the formula of TBAEuxM1-x(TTA)4 (TBA = tetrabutylammonium; M = La or Gd; TTA = 2-thenoyltrifluoroacetonate), are synthesized by co-precipitation. In the solid solutions, the emission efficiency of Eu3+ is significantly increased with the presence of non-luminescent chelates TBALa(TTA)4 and TBAGd(TTA)4. Low temperature luminescence spectroscopy studies indicate that the TTA- ligands in these non-luminescent chelates do emit phosphorescence with long lifetime. However, the ligand phosphorescence is strongly quenched in solid solutions with the luminescent chelate TBAEu(TTA)4, providing strong evidence for intermolecular energy transfer through the triplet excited states of the ligands. A quantitative analysis of Eu3+ emission enhancement and TTA- phosphorescence quenching reveals that each Eu3+ center may receive excitation energy from about 30 TTA- ligands, suggesting that the excitation energy has become exciton-like in the solid solutions. Based on the crystallography analysis of TBALn(TTA)4, it is discovered that TTA- ligands in neighboring Ln(TTA)4- units may form π-π stacks with intermolecular distance ≤3.5 Å, thus enabling efficient triplet exciton diffusion via exchange interaction.

Fourier Transform Infrared Spectroscopy Monitoring of Dihydroartemisinin-Induced Growth Inhibition in Ovarian Cancer Cells and Normal Ovarian Surface Epithelial Cells.

PURPOSE: Ovarian cancer is the most lethal of gynecological malignancies. Dihydroartemisinin (DHA), a derivative of artemisinin (ARS), has profound effects against human tumors. The aim of this study was to provide a convenient, cost-efficient technique, Fourier transform infrared (FTIR) spectroscopy, to monitor and evaluate responses to DHA-induced growth inhibition of ovarian cancer cells. METHODS: Cell growth and viability and the 50% inhibitory concentration (IC50) of DHA were assessed by the MTT assay. FTIR spectroscopy was used to monitor cells following DHA treatment, and data were analyzed by OMNIC 8.0 software. RESULTS: DHA can decrease the viability of ovarian cancer cells and normal cells, but cancer cells were more sensitive to this drug than normal cells. Spectral differences were observed between cells with or without DHA treatment. In particular, an increase in the amount of lipids and nucleic acids was observed. The band intensity ratio of 1454/1400, and the intensity of the band 1741 cm-1 increased, indicating stronger absorption after DHA treatment. Moreover, the differences were larger for the cell lines that were more sensitive to DHA. CONCLUSION: The spectral features provided information about important molecular characteristics of the cells in response to chemicals. These findings demonstrated the possible use of FTIR spectroscopy to evaluate DHA-induced growth inhibition effects in ovarian cancer cells and provided a promising new tool for monitoring cell growth and the effects of antitumor drugs in the clinic in the future.

Characterization of ovarian cancer cells and tissues by Fourier transform infrared spectroscopy.

BACKGROUND: Ovarian cancer is the most lethal of gynecological malignancies. Fourier Transform Infrared (FTIR) spectroscopy has gradually developed as a convenient, inexpensive and non-destructive technique for the study of many diseases. In this study, FTIR spectra of normal and several heterogeneous ovarian cancer cell lines as well as ovarian cancer tissue samples were compared in the spectral region of 4000 cm- 1 - 600 cm- 1. METHODS: Cell samples were collected from human ovarian surface epithelial cell line (HOSEpiC) and five ovarian cancer cell lines (ES2, A2780, OVCAR3, SKOV3 and IGROV1). Validation spectra were performed on normal and cancerous tissue samples from 12 ovarian cancer patients. FTIR spectra were collected from a NICOLET iN10 MX spectrometer and the spectral data were analyzed by OMNIC 8.0 software. RESULTS: Spectral features discriminating malignant tissues from normal tissues were integrated by cell line data and tissue data. In particular changes in cancerous tissues, the decrease in the amount of lipids and nucleic acids were observed. Protein conformation and composition were also altered in some cancer cells. The band intensity ratio of 1454/1400 was higher in normal cells/tissues and lower in cancer cells/tissues. CONCLUSION: The spectral features revealed the important molecular characteristics about ovarian cancer cells/tissues. These findings demonstrate the possible diagnostic use of FTIR spectroscopy, providing the research model and evidences, and supporting the future study on more tissue samples to establish a data bank of spectra features for the possible discrimination of ovarian cancers.

Investigation on the relationship between solubility of artemisinin and polyvinylpyrroli done addition by using DAOSD approach.

In this work, we investigated the influence of polyvinylpyrrolidone (PVP) on the solubility of artemisinin in aqueous solution by using quantitative 1H NMR. Experimental results demonstrate that about 4 times of incremental increase occurs on the solubility of artemisinin upon introducing PVP. In addition, dipole-dipole interaction between the ester group of artemisinin and the amide group of N-methylpyrrolidone (NMP), a model compound of PVP, is characterized by two-dimensional (2D) correlation FTIR spectroscopy with the DAOSD (Double Asynchronous Orthogonal Sample Design) approach developed in our previous work. The observation of cross peaks in a pair of 2D asynchronous spectra suggests that dipole-dipole interaction indeed occurs between the ester group of artemisinin and amide group of NMP. Moreover, the pattern of cross peaks indicates that the carbonyl band of artemisinin undergoes blue-shift while the bandwidth and absorptivity increases via interaction with NMP, and the amide band of NMP undergoes blue-shift while the absorptivity increases via interaction with artemisinin. Dipole-dipole interaction, as one of the strongest intermolecular interaction between artemisinin and excipient, may play an important role in the enhancement of the solubility of artemisinin in aqueous solution.

Use of CuO Particles as an Interface in LC-FTIR Analysis.

In this study, the feasibility of using copper oxide (CuO) as an interface for the coupling of liquid chromatography (LC) and Fourier-transform infrared (FTIR) spectroscopy was investigated. CuO exhibits low absorption in the 4000 to 1000 cm-1 FTIR spectral region. In addition, LC-FTIR using CuO as the interface was extended to the analysis of sample mixtures containing benzamide and dioctyl sebacate; both analytes were successfully separated. After complete removal of the mobile phase, benzamide and dioctyl sebacate were successfully identified from the FTIR spectrum. Surprisingly, the interference from adsorbed water or conventionally used LC solvents in the FTIR spectrum was completely eliminated by using CuO particles as the interface in the off-line hyphenation of LC-FTIR. Based on these results, CuO demonstrates potential as an ideal interface for LC-FTIR analysis.

[On the Tributylphosphate-Based Super-Concentrated HCl System].

We reported a new super-concentrated hydrochloric acid system prepared by using tri-n-butyl phosphate (TBP)-constructed reversed micelles at ambient temperature and pressure. According to the titration result, the molar ratio of H+ to H2O (denoted as nH+/nH2O) in the super-concentrated HCl range from 0.50 to 1.50 which are higher than that in saturated aqueous HCl bulk solution (0.28). Significant a moment of hydrochloric acid is confined in W/O reversed micelles. Therefore, the behavior and status of HCl are different from those of conventional bluk solution. FTIR spectroscopic results demonstrate that a significant amount of HCl remains in the molecular form rather than being ionized into H+ and Cl-. Thus, super-concentrated HCl provides an extraordinary chemical environment which may have significant influence on certain substances. We found that the color of the solution is reddish brown when copper ion is dissolved in super-concentrated HCl, while the color of the saturated HCl aqueous solution (37 Wt%) containing copper ion is green. That is to say, the copper ions exist in a special state under the unique chemical environment of super-concentrated HCl. UV-Vis-NIR spectra indicate that both d-d transition band and charge transfer transition band of copper ions in super-concentrated HCl solution underwent significant variations. In addition, copper ions also have obvious influence on the hydrogen bond network among HCl in the super-concentrated HCl solution. Remarkable variation is introduced in the H-Cl stretching band in FTIR spectra.

[Influence of Concentration Sequence on the Signal-to-Noise Ratio of Cross Peaks of 2D Asynchronous Spectra Generated by Using the DAOSD Approach].

In the present work, computer simulation was performed on a model chemical system where two solutes (denoted as P and Q, respectively) are dissolved in the same solution. Under intermolecular interaction between P and Q, part of P undergoes subtle structural variation and converts into U while part of Q converts into V. The strength of intermolecular interaction can be characterized by the corresponding equilibrium constant K. Our preliminary studies indicate that the S/N ratio of cross peak increases considerably as n increases. Moreover, the S/N ratio of the cross peak from the asynchronous spectra can be improved significantly when the suitable concentrations of P and Q are adopted. This work is helpful for a selection of suitable concentration sequence to maximize S/N ratio of cross peaks in the 2D asynchronous spectra generated by using the DAOSD approach proposed in our previous study so that weak intermolecular interaction can be probed.

Investigation on the trioctylphosphine oxide-based super-concentrated HCl system.

We report a new super-concentrated HCl system prepared by using trioctylphosphine oxide (TOPO)-based reverse micelles. The observed molar ratio between acid and water (nHCl/nH2O) in the super-concentrated HCl are much higher than that in the saturated aqueous HCl solution (0.28). Moreover, FT-IR spectroscopic results reveal that a significant amount of HCl remains in the molecular form rather than being ionized into H(+) and Cl(-). As a result, two H-Cl stretching bands can be observed in the FT-IR spectrum. The super-concentrated HCl provides a unique chemical environment in which many chemical substances occur in unusual states. For example, the color of super-concentrated HCl solution containing copper ion was found to be reddish brown rather than green as in conventional state. UV-Vis-NIR spectral results indicate that both d-d transition band of Cu(2+) and charge transfer band of Cl-Cu in super-concentrated HCl underwent significant variation. Additionally, copper ions bring about remarkable variation on the hydrogen bond network among HCl in the super-concentrated HCl solution as demonstrated by FT-IR spectra. According to the EXAFS results, we suggest that copper ion may occur as HCuCl3 in the super-concentrated HCl.

[Studies on carbonization of saccharides by using aqueous solution of various acids].

The authors tried to establish an approach to use acids to convert biomass into a fuel with higher carbon content and lower oxygen content in a zero-energy-consumption fashion. Considering that biomass is composed of monosaccharide, we used aqueous solutions of variation acids including hydrochloric acid, sulfuric acid and perchloric acid to treat 2-deoxy-ribose and fructose at ambient temperature and pressure. Black substances were produced after a period of time when 2-deoxy-ribose and fructose were mixed with aqueous solutions containing 8 mol · L(-1) acids. The black substance was collected and characterized by using elemental analysis, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Elemental analysis results indicate that the contents of carbon increases significantly in the black substances in comparison with 2-deoxy-ribose and fructose. Moreover, XPS results indicate that the content of oxygen in the black substance undergoes a significant decrease compared with pure 2-deoxy-ribose and fructose. In the XPS spectra, the is peaks of 2-deoxy-ribose, strong sub peak at 286. 05 eV, which is assigned to carbon linked to oxygen directly, dominate in the C is peak envelop. After treatment by HClO4, the peak decreased dramatically. This result also supports the conclusion that the content of oxygen in mono-saccharide is significantly reduced after treatment by acids. In the FTIR spectra of the black substances, strong peaks can be observed around 1 600 cm(-1), indicating that C==C bond is formed in the product. The above results suggest that treatments with acids may be developed as a new zero-energy-consumption approach to convert biomass in a new fuel with improved energy output efficiency.

[Study on the meningoima using FT-mid-IR spectroscopy].

In the present investigation, 24 cases of meningoima tissues (including 12 cases of benign tumor and 12 cases of malignant tumor 12) were detected using FT-mid-IR spectroscopy linked with attenuated total reflectance (ATR) accessory. These FTIR spectra obtained from the above-mentioned meningoima tissues were analyzed and compared. Significant differences were found in the spectral features of different kinds of meningoima tissues for example fibrous type meningoima and endothelioid meningoima; and for the same type of meningoima tissues the significant differences in the spectram features can be also observed with the increase of grade malignancy. The malignant tumor can be distinguished primarily from benign tumor by the changes of position, shape and intensity of infrared absorption bands, particularly in the ranges of 1 000-1 500 cm(-1). The results show that the peak position of the bands (such as 1 160 cm(-1)) can be used to distinguish the characteristic of meningoima which are in agreement with the pathological results. The accuracy is larger than 85%. These results demonstrate that FT-mid-IR spectroscopy exhibits prospect to develop a novel, non-invasive and rapid method for the diagnosis the brain tumors.

[New progress in noninvasive method of blood glucose measurement using FT-mid-IR spectroscopy].

The blood glucose concentrations of volunteers from diabetes patients and healthy adults (all patients and volunteers who joined this experiment gave their consents) were measured by using a modified WQF-200 FTIR spectrometer with a newly designed ATR accessory from the Beijing Rayleigh Analytical Instrument Corp. The determination basis for this technique from the physiological point of view is also discussed based on the experimental results, which indicated that the glucose measured by the FT-Mid-IR ATR instrument is from the secretions on the skin and glucose components within the body. The secreted glucose components will increase with the time increasing. The authors' previous study demonstrated 1 120 cm(-1) band as an index to characterize the blood glucose. During the experiments, the authors used the band of 1 455 cm(-1) as internal standard because of its stability, and because the relative intensity of I1 120/I1 455 band possesses the higher sensitivity. Meanwhile, from the spectra, the relative intensity of I1 120/I1 455 band of the glucose in both sources exhibits a linear relationship with blood glucose concentration within the body. The dried blood has the similar spectra as fingers'. The fingers' spectra will exhibit higher sensitivity if the time of measurement is longer after washing hand, and the results showed that when measured 10 minutes after washing hand, the sensitivity will be higher than that when measured 4 minutes after washing hand. All the results can be used in promoting a convenient, rapid and noninvasive way to monitor the continuous variation of blood glucose concentration of diabetes patients in real time.

[Study on the mechanism of Ca2+-buffering by sodium glycodeoxycholate micelles].

In the present article, NaGDC was used to study the Ca(2+)-buffering capability of bile salt micelles. NaGDC is a naturally occurring bile salt which constitutes approximately 10 molar percent of bile salt composition in gallbladder. The authors selected glycine conjugated bile salts NaGDC because it precipitates with Ca2+ ions fast. The Ca(2+)-buffering property of sodium glycodeoxycholate (NaGDC) micelles was studied by utilizing turbidity titration, quasi-elastic light scattering (QELS), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). When the concentration of NaGDC was above the CMC, the precipitation of Ca2+ ions with NaGDC was buffered. The Ca(2+)-buffering capability was enhanced when the concentration of NaGDC increased. The possible mechanism of Ca(2+)-buffering by NaGDC micelles was discussed. When the concentration of NaGDC was below the CMC, the Ca2+ ions reacted with GDC-anions to form the Ca(GDC)2 precipitation. However, at the concentration above the CMC, NaGDC simple micelles were connected by Ca(2+)-bridge to form larger fibriform micelles via the interaction of carboxyl groups of NaGDC simple micelles with Ca2+ ions. When the ratio of Ca2+ to Na+ was enhanced to the fixed value, Na(n)Ca(m) (GDC)(n+2m) complexes were precipitated by the further addition of Ca2+ ions.

Fourier transform infrared spectroscopy of gallbladder carcinoma cell line.

BACKGROUND: Fourier transform infrared (FT-IR) spectroscopy is a physical method applied to the study of cellular changes at the molecular level in various normal and diseased human tissues, including cancer. This study was undertaken to establish a cellular basis for the diagnosis of carcinoma tissue, using FT-IR spectroscopy to study a carcinoma cell line and investigating the specific spectral features of the cell line. METHODS: The FT-IR spectra of cultured gallbladder carcinoma cells (GBC-SD) smeared on a BaF2 window were measured with a Nicolet Magna750-II FT-IR spectrometer. A comparative study was subsequently carried out between the spectra of cultured gallbladder carcinoma cells and those of corresponding carcinoma tissue. RESULTS: Several infrared spectral features were obtained, and the results suggest that the spectral features of the carcinoma cell line reflect those of carcinoma tissue, though the latter are more complex, probably due to the intrinsic complexity of the tissue. CONCLUSION: The diagnosis of carcinoma tissue by FT-IR spectroscopy has a sufficient cellular basis.

[Study on the effect of C-terminal acidic protein on the prokaryotic expression of alpha-thionin by FTIR microspectroscopy].

Fourier transform infrared (FTIR) microspectroscopy was used to investigate the effects of C-terminal acidic protein on the secondary structure of wheat alpha-thionin in the absence of signal peptide during the prokaryotic expression process. SDS-PAGE analysis revealed that the presence of acidic protein gave rise to the formation of inclusion body, however, the absence of acidic protein greatly enhanced the solubility of the heterogenous protein expressed in E. coli BL21(DE3) with the induction of 1 mmol x L(-1) IPTG at 37 degrees C. Difference spectra in amide I region were obtained by subtraction between the spectra of intact cells containing S and Sc, which corresponds to the absence and presence of C-terminal acidic proteins, respectively. The second derivative of the difference spectra measured 2 h after induction showed one principal component at approximately 1 630 cm(-1), while no significant peak appeared at the same peak position when the spectra before induction were compared. Combined with SDS-PAGE of recombinant protein, the authors presumed that the peak absorption at approximately 1 630 cm(-1) is most likey to be assigned to protein aggregate within inclusion body. Gaussian curve-fitting was done on the Fourier self-deconvolution spectra within amide I region of intact cells containing S and Sc. The experimental data revealed that the relative content of aggregate absorption at (1 629 +/- 1) cm(-1) gradually increased with induction time, which is consistent with the results of SDS-PAGE. Simutaneously, the formation of aggregate gave rise to the increase of alpha-helix, as well as the decrease of beta-turn and random coil in the case of Sc. It was not the case for S, however, where random coil experienced the increase in the relative average fractions, while beta-turn and beta-sheet at (1 629 +/- 1) cm(-1) behaved in different ways. The above mentioned phenomenon indicated that beta-sheet and random coil are most likely to transform into aggregate and alpha-helix with the introduction of C-terminal acidic protein.

[Periodic and fractal precipitation in ATP-Co(2+)-decoxycholate gel system].

In the simulation experiments in vitro of the formation of gallstone, adenosine-triphosphate(ATP)-Co(2+)-deoxycholic acid(DC) gel system was chosen to study the periodic precipitation progress. The effect of ATP on the Co(2+)-DC gel system was also determined, and the structure of the periodic precipitation formed was characterized by FTIR. The results show that the patterns formed in the systems with ATP are different, ATP affected the rate and structure of precipitation through its variable participation in the metal coordination complexes as judged by the phosphate P=O bands and the deoxycholate COO- symmetric and asymmetric vibration bands as measured by FTIR Theses spectroscopic differences were correlated with color and pattern differences in the precipitates. ATP has a more remarkable function than AMP to the modes of patterns, meanwhile the system patterns transform from fractal to periodic precipitation. There is a complex interaction among ATP, sodium deoxycholic and Co2+ with a transparent crystal produced. The crystal is deoxycholic acid and the periodic precipitation is composed of ATP and DC covalent to Co2+. These results indicate that stone formation and remodeling is a dynamic, nonlinear progress. Much of the precipitate, as judged by local differences in composition, is not in equilibrium with the general gel environment. The authors conclude that the formation of gallstone features complex and nonlinear chemical character, in which nucleotides as living material play a very important role.

[Formation of W/O microemulsions in TBP-Pd(II)-HCl extraction system and spectroscopic research on the evolution of solution aggregation structure].

The formation of W/O microemulsions in the extraction system TBP-Pd(II)-HCl was investigated. The solution structural evolution of the palladium loaded organic phases, with the variation in the content of acid into the organic phases, was characterized by various spectroscopic techniques such as DLS, FTIR and 31P-/1H NMR. The results indicated that (1) the extraction behaviors of palladium was related to the formation of W/O microemulsion structure in the loaded organic solutions. Because of the co-extraction of hydrochloric acid, there formed the microscopic aggregates in the loaded organic phases. (2) The variation in the HCl content in organic phase resulted in corresponding changes in solution structure. With the increase in the HCl content, the average radii of nanoscopic aggregates in the organic phases increased and then decreased. The extraction of HCl into the organic phase exhibited a distinct impact on the O-H stretching vibration and O-H-O bending vibration of water molecules in the microscopic W/O micelles. FTIR spectra of the organic phase saturated with acids show that the broad band of O-H stretching vibration of water extended to a very wide range and overlaped with the C-H stretching vibration bands. The higher the acid concentration in the organic phase was, the greater the overlapping. On the other hand, it was also observed that a remarkable change appeared in the O-H-O bending vibration of water and the stretching vibration of P=O in TBP molecules shifted to lower frequency. With the increase in acid content in the TBP organic phases, the observed 31P NMR chemical shifts decreased and varied to up-field; whereas the 1H NMR chemical shift of H+ increased and even became larger than that of deuterium chloride-d at a lower frequency field. The changes in delta 31P to opposite direction of delta H+ means that TBP molecules were associated with acid protons and water molecules in microemulsion pools to form RP=O x H+ or RP=O x H3O+, and then interacted with PdCl4(2-) complex ions, which finally led to the extraction of palladium into the organic phase. (3) When forming the W/O reversed micelles/microemulsions, the concentration of acid within the microscopic micelles was even higher than that of saturated concentrated hydrochloric acid. It was the microscopic structural changes in organic phase microemulsion "water pool" that resulted in the corresponding variations in the palladium extraction behaviors.

[THz absorption spectra of several carbohydrate derivatives].

Intermolecular hydrogen bond vibrations may be observed in the THz range. Carbohydrates are important bio-molecules, and are the typical systems for the study of hydrogen bonds. Carbohydrate derivatives have critical biological functions, and there are extensive hydrogen bond networks in molecular system, therefore, they would have various bands in the THz region. The THz absorption spectra of several carbohydrate derivatives were measured using a THz apparatus at room temperature. The THz bands are as follows: 1.17, 1.35, 1.93 and 2.23 THz for isopropyl-beta-D-thioglucopyranoside; 1.93 THz for isopropyl-beta-D- thiogalactopyranoside; 1.87 THz for methyl-(tetra-O-acetyl-beta-D-galactopyranoside); 1.23, 1.70, 1.84 and 2. 23 THz for O-(2, 3, 4, 6-tetra-O-acetyl-beta-glucopyranosyl)-N-hydroxysuccinimide. The results indicate that different samples have various bands that originated from collective modes of the whole molecules and especially isomers can be distinguished, showing that THz method is sensitive to the molecular structures and spatial configurations and is a helpful complement of IR spectroscopy.

[Studies on coordination and hydrogen bond intermolecular interaction using 1D & 2D FTIR spectroscopy].

Two-dimensional (2D) correlation spectroscopy is a powerful method to study the intermolecular interactions between different molecules/functional groups. In the present paper, variable concentrations were selected to construct 2D synchronous spectrum for studying the weak intermolecular interactions in solutions. Mathematical analysis performed on 2D synchronous spectra using variable concentration as an external perturbation shows that the "Orthogonal Sample Design Scheme" is necessary for eliminating the interfering cross peaks in 2D synchronous spectra. The authors prepared four mixed-solutes-solutions whose concentration series satisfy the "Orthogonal Sample Design Scheme" for each chemical system and the consequent 2D synchronous spectrum was calculated from the corresponding four 1D spectra. Thus, by 1D & 2D FTIR spectra together with solid grinding reaction, the intermolecular interactions in two chemical systems (Sodium 2-Aminobenzoate/NdCl3 in aqueous solution, and 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester (PC88A)/Naphthenic Acid (NA) in heptane solution) were studied, where the intermolecular interactions only induce subtle spectral variations in conventional 1D spectra. First, the cross peaks between f-f transition bands of Nd3+ ion at 521, 574, 741, 795 and 865 nm and pi-pi transition band of Sodium 2-Aminobenzoate at 308 nm in 2D synchronous spectrum confirm the coordination interaction between Sodium 2-Aminobenzoate and Nd3+. Solid grinding reaction between Sodium 2-Aminobenzoate and NdCl3 and FTIR spectra of the product indicate that the vibration bands of amino, carboxyl groups from sodium 2-aminobenzoate show considerable changes. Based on the spectral result above, a conclusion is drawn that Nd3+ can coordinate with Sodium 2-Aminobenzoate by amino and carboxyl groups. Second, the cross peaks between POH stretching band of PC88A at 983 cm(-1) and COOH stretching band of NA at 1 710 cm(-1) in 2D spectra confirm the interaction between PC88A and NA. Subtraction spectrum demonstrates that when PC88A is mixed with NA in heptane solution, and P=O stretching band of PC88A shifts from 1 199 to 1161 cm(-1), and POH stretching band shifts from 983 to 965 cm(-1). Based on the spectral result above, a conclusion was made that PC88A and NA can interact with each other by forming new assemblies with POH and COOH groups.

[FTIR spectroscopic study on carcinoma cells].

The aim of this research is to establish the cell basis for the carcinoma tissue diagnosis by exploring a method to obtain the FTIR (Fourier transform infrared) spectra of the cultured carcinoma cells with FTIR spectroscopy and investigating the special spectral features of the carcinoma cells compared with the carcinoma tissues. In the present paper, the gastric carcinoma tissues confirmed by histology were measured using a Nicolet Magna750-II FTIR spectrometer and the corresponding FTIR spectra were obtained. The cultured gastric carcinoma cells (SGC7901) were centrifuged to provide a small pellet of cells for FTIR analysis. The cell pellet was then placed on a specially designed salt plate made of BaF2. Then the infrared spectra were recorded by the same equipment. Based on the previously established criteria, a comparative study was subsequently carried out between the spectra of the cultured carcinoma cells (SGC7901) and that of the corresponding gastric tissues. Several infrared spectral features of the carcinoma cells were obtained: the different bands between cells and tissues locate in the range of 3 000-3 600 cm(-1) and 1 640 cm(-1) which are the range of the hydroxy stretching and blending bands of H2O. There are more H2O out of carcinoma cells in carcinoma tissues, so the strong bands of H2O cover the distinctive bands of carcinoma cells in carcinoma tissues. Although the carcinoma tissue is more complicated, which might originate from the intrinsic complexity of the tissue, the results suggest that the spectral features of the carcinoma cells can be well reflected by that of the carcinoma tissue. This study shows that the diagnosis of carcinoma tissue by FTIR method exhibits sufficient cell basis.

Terahertz absorption spectra of some saccharides and their metal complexes.

In this work, THz absorption spectra of some saccharides and their metal complexes were measured. The main purpose of this work is to investigate the M-O vibrations, intermolecular and intramolecular hydrogen bonds and other vibrations in the FIR region using powerful spectroscopic techniques adopting the metal-sugar complexes prepared in our laboratory. The M-O vibrations in the FIR spectra of metal-sugar complexes indicate the formation of metal complexes. The THz spectrum of glucose below 100cm(-1) was measured at first to confirm the THz experimental method. Characteristic absorption bands in the spectra of various samples are observed. THz spectra of saccharides below 100cm(-1) often have several absorption bands, and different saccharides have various absorption peaks in the THz region, which may be used to distinguish different saccharides. The differences in the number of bands observed are related to different structures of the samples, and these absorption bands are related to the collective motion of molecules. But the THz spectra of their metal complexes are different from the ligands, and no band appears in the region below 50cm(-1) at the present experimental condition, which indicates that THz spectroscopy may also be helpful to identify the formation of metal-sugar complexes, and the changes after complexation in the THz spectra below 100cm(-1) may be related to different metal ions. The metal-sugar complexes with similar crystal structures resemble mid-IR spectra, but their THz spectra may have some differences.