Biomedical subjects

Shi-fu Weng

Publications and source records attributed to Shi-fu Weng.

17 recordsLinked to original sources

PubMed2006

[FTIR spectroscopic studies of hydration effect on the molecular structure of polyether urethane].

The interaction between water molecules and the polar groups in linear polyether urethane was studied by FTIR and subtraction spectroscopy technique. Direct proofs of the combining of water molecule and carbonyl group were obtained. The reorganizations of the ether linkage, carbamate, and carbon-hydrogen chain after hydration were also observed. These results suggest that the FTIR and subtraction spectroscopy technique could be a useful tool to investigate the hydration mechanism of polymer materials.

English Abstract↗

PubMed2006

[Structural study on the transparency of cross-linked polyester polyurethane].

The polyurethane material with cross-linked structure was synthesized using half pre-polymerization method. IR, UV-Vis, TEM and XRD methods, and physical properties measurements indicate that different moulding temperatures influence the apparent transparence of polyurethane and abrasive performance, and the nature of these changes is related to the conditions of processand chemical reaction which lead to gradual micro-phase separation of the polyurethane molecules with different compositions, resulting in the domain-forming with the size of sub-micro-, micro- and even more than ten micro-meters. Such domains aggregate one another to form particles with different shapes and complicated structures. The increase in the amount and size of these heterogeneous particles, distributed in the medium of transparent polyurethane, is the main cause that brings on an opaque appearance of polyurethane.

English Abstract↗

PubMed2005

[Synthesis, characterization and fluorescence properties of binary and ternary rare earth complexes with N-phenylanthranilic acid and 1, 10-phenanthroline].

Some novel binary and ternary complexes of rare earth (Tb) with N-phenylanthranilic acid and 1,10-phenanthroline were synthesized and their compositions were characterized by elemental analysis. The compositions of the complexes have been confirmed to be TbL3. 4H2O and TbL3 phen.2H20 (L: N-phenylanthranilic acid, phen: 1;10-phenanthroline). The spectroscopic properties of the complexes were discussed. The result shows that the luminescence intensities of binary and ternary complexes were decreased by N-phenylanthranilic acid and 1,10-phenanthroline. It is indicated that the intensity of Tb depends on the structure of ligands. The structure, energy transfer and energy matching were studied, and it is concluded that the structure of complex affects the luminescence properties of the complexes.

Fenamates↗

PubMed2005

[Characterization of the orientation of polymer material by non-polarized raman laser light spectroscopy].

The non-polarized Raman laser light was used to investigate the anisotropic polymers including polypropylene fiber, nylon 6 flat fiber, and polyethylene pipe. The Raman spectra of the same samples with different location relative to the incident direction of laser beam show obvious differences. The present result extends the application of Raman spectroscopy to the characterization of oriented polymers samples.

Anisotropy↗

PubMed2005

[The studies on YCl3/PEU system by rheology analysis and FTIR].

FTIR spectroscopy and rheology analysis were applied to study the YCl3/PEU system. It is apparent that modification with lanthanide complexes such as yttrium leads to a slight increase in viscosity of the polyether urethane solution. The authors conclude that this may be due to the interaction between the lanthanide ions and the polar group in urethane.A new band appears at 1650 cm(-1) in the infrared spectra of the YCl3/PEU system, which corresponds to the new carbonyl structure formed through the coordination with yttrium cations. The dynamic rheological behaviors of the solutions demonstrate the interaction furthermore. A higher molecular weight formed with the higher concentration of the lanthanide ions in this DMF solution. And this could be an effective method to characterize the structure of the polymer solutions.

English Abstract↗

PubMed2004

Discrimination of normal and malignant gastric tissues with FTIR spectroscopy and principal component analysis.

In this paper, the identification of normal and malignant gastric tissues, including 11 cases of cancerous tissues and 10 cases of normal tissues, was investigated using mid-IR spectroscopy and principal componentanalysis (PCA). The results indicated that the difference between cancerous and normal tissues was found in the first principal component. The IR detection and PCA results are in agreement with the biopsy results. The combination of these two methods might provide a new opportunity for clinical application.

Algorithms↗

PubMed2004

[Synthesis and luminescence properties of europium (III ) complexes with camphoric acid and 1,10-phenanthroline].

The complexes of europium(II) with camphoric acid and 1,10-phenanthroline have been synthesized and characterized by elemental analysis, (1)H NMR, IR and FT-Raman. The compositions of the complexes have been confirmed to be Eu2 (CA)3.(2)H2O and Eu2 (CA)3 (phen)2 (CA: camphoric acid, phen: 1, 10-phenanthroline). In addition, the camphoric acid and 1, 10-phenanthrolinemixed coordination compounds of Eu3+ -La3+ have been synthesized. Three-dimensional fluorescence spectra showed that the optimum excitation wavelength was 310 nm, and the strongest emission wavelength was 612 nm. When 310 nm light was used as an excitation wavelength, the seven bands due to (5)D0 - (7) F0 (579 nm), (5)D0 - (7)F1 (594 nm), (5)D0 - (7)F2 (612 and 620 nm), (5)D0 - (7)F3 (650 nm) and (5)D0 - (7)F4 (689 and 697 nm) were observed between 550-700 nm, in which (5)D0 - (7)F2 transitions contain two lines (612 and 620 nm), and (5)D0 - (7)F4 transitions also contain two lines (689 and 697 nm). The excitation spectra showed that excitation band was from 240 to 340 nm, and the maximum was at about 310 nm. The fluorescence studies on all of samples showed that the fluorescence intensities of europium ions were sensitized by lanthanum ions, but the peak position of their emission band did not shift obviously.

Camphor↗

PubMed2004

[Investigation of PP/PE blend with FTIR mapping].

The polypropylene/polyethylene (PP/PE) blends with different weight ratio were studied by FTIR spectroscopy. The characteristic absorption bands of PP and PE in different blends were compared. It was found that the ratio of the characteristic absorption peak areas of PP to those of PE is correlated with the weight ratio of PP to PE in the blends. Based on the above results, FTIR mapping technique was applied to characterize the samples prepared by embedding PP fiber into molten PE film, and the distribution of PP and PE in the blends can be obtained from the ratio of the characteristic peak areas of PP to PE. Good agreements have been observed between the IR mapping image and the image obtained using polarized optical microscope. These results indicated that FTIR mapping technique is an effective tool to investigate the phase separation behavior of polymer blends based on the ratio of the characteristic peak areas of different polymers.

English Abstract↗

PubMed2004

[Study on the transition of green, yellow fluorescence of ternary complexes of Tb-benzoic acid-1,10-phenanthroline].

In this paper, ternary solid complexes of Tb-benzioc acid-1,10-phenanthroline have been synthesized. Compared with binary complexes of Tb-benzioc acid, their properties were investigated. The results showed that the second ligand-phenanthroline enhanced the fluorescence intensities of Tb3+, and shortened its fluorescence lifetime, and it was found that the aggregative state influenced the luminescence properties of ternary complexes. When particulates dispersed to a certain degree, the probability of 5D4-->7F5 transition of Tb3+ was great, so, green fluorescence was observed for the complexes. With the aggregation of particles, the probability of 5D4-->7F5 transition of Tb3+ decreased, while the probability of D4-->7F3 transition increased. Therefore, ternary complexes of Tb-benzoic acid-1,10-phenanthroline exhibited yellow fluorescence. In addition, spectroscopic properties of the complexes were investigated.

Benzoates↗

PubMed2004

[The interaction between La and polyurethane system].

A series of polyether polyurethane (PU)-LaCl3 composites with different lanthanum contents were prepared. DSC results indicate that LaCl3 promotes phase transition behavior of the LaCl3/PU composites, which causes the endothermic peak at 11.58 degrees C to disappear. FTIR spectroscopy demonstrates that significant variation can be observed. The peak at 1633 cm(-1) attributed to carbonyl vibration and the peak at 3311 cm(-1) attributed to N-H stretching band moves to 1647 cm(-1) and 3355 cm(-1), respectively, when LaCl3 is introduced into the PU system. A new band (-200 cm(-1)) assigned to the La-O band was observed, and the far IR result provided a direct evidence of the coordination between La3+ ion and C=O group of PU system.

English Abstract↗

PubMed2004

[The design and application of domestic mid-IR fiber optics].

The combination of mid-IR fiber optics and FTIR has made the non-invasive determination of samples in situ, with long distances, and in vivo possible. In this paper domestic mid-IR fiber optics was improved to investigate the transmission ability of fiber optics and its application to the sample determination. New design was applied to obtaining one bare fiber optics, which has a minor energy loss and higher signal-to-noise ratio. The spectra of H2O/EtOH and tissue samples were measured using the new designed fiber optics and the results show that home-made mid-IR fiber optics can be applied to the field of determination of general and biological samples.

English Abstract↗

PubMed2003

[FTIR spectroscopic study of normal and malignant tissues of rectum].

Fourier transform infrared (FTIR) spectroscopy was used to study the normal and malignant tissues of rectum. The FTIR spectra of tissues were measured by Nicolet Magna IR-750 spectrometer equipped with mid-infrared fiber optics. The results show that the intensity ratios of five pairs of bands can be used to distinguish the normal and malignant tissues. In the spectra of malignant tissues the relative intensities ratios of I2,873/I2,852 and I1,312/I1,245 were higher than those of normal ones; however, the ratios of I1,745/I1,643, I1,458/I1,400 and I1,162/I1,082 were lower. These results, proved by data-analysis of spectra from 21 patients, were generally shown in the spectra of rectum tissues. The study of near-malignant tissues (one centimeter beside the malignant point) of rectum by FTIR shows that these ratios of bands were in a transient state between normal and malignant rectum tissues.

Humans↗

PubMed2003

[Interaction between polyamide and zinc salt].

X-ray diffraction and FTIR spectroscopic method have been used to investigate the interaction between the amide group of nylon 6 and zinc chloride. The nylon sample obtained by adding formic acid solution of nylon into aqueous solution saturated by zinc chloride is significantly different from the nylon precipitated after mixing formic acid solution of nylon and water. X-ray diffraction results demonstrate that nylon precipitated from water has crystallization while the sample acquired from saturated solution of ZnCl2 remains amorphous. FTIR spectroscopic study shows that the interaction between zinc ion and the amide group of nylon 6 brings about significant variation of amide I and II bands and prevents the crystallization of nylon. The interaction between nylon and zinc ions may be helpful in the development of a new method of manufacturing new nylon material with superior performance.

Chlorides↗

PubMed2002

[Preparation and spectroscopic properties of terbium polypropenic acid film].

The bonding-type rare earth polymers-polypropenic-acid terbium film was prepared through the bonding way. Three-dimension fluorescence spectra showed that the optimum excitation wavelength was 306 nm, the strongest emission wavelength was 544 nm. The terbium polypropenic-acid film showed the characteristic Tb3+ emission when excited at 306 nm due to 5D4-7FJ transition (J = 6, 5, 4 and 3). The emission maximum at 544 nm was ascribed to 5D4-7F5 transition of Tb3+ and presented strong green emission. The luminescent properties of Tb3+ were not affected by polymerism of propenic-acid and the transparency of polypropenic-acid in visible light region was not affected by the dopping Tb3+. The fluorescence properties and spectroscopic properties of the terbium polypropenic-acid were investigated by excitation spectrum, emission spectrum, IR, far-IR, and Raman spectrum.

Organometallic Compounds↗

PubMed2002

[FTIR and FT-Raman spectroscopic investigation on two complexes of La3+ with galactitol].

FTIR and Raman spectroscopy were used to investigate the two complexes of LaCl3 with galactitol in this paper. The results shows that La ion can complex with galactitol in 1:1 and 2:1 proportion. The FTIR and Raman spectra of the two complexes both exist some differences that prove LaCl3 and galactitol really form two different complexes. In the FTIR spectra nu OH is strong peaks and nu CH peaks are very weak whereas nu CH pband become stronger than nu OH peaks. So FTIR and Raman spectra can provide complementary information.

Chelating Agents↗

PubMed2002

[FTIR microspectroscopic investigation on the stained and unstained histotomic section of oral tissues].

In this paper, stained and unstained samples of oral tissues have been investigated using FT-microspectroscopy. The experimental results demonstrated that staining did not influence the characteristic features of the FTIR spectra of the oral tissues, thereby providing abundant opportunity of further understanding of the structural-spectral relationship of normal and malignant tissues.

Carcinoma, Squamous Cell↗

PubMed2002

[Synthesis and spectroscopic characterization of complexes of trivalent lanthanide ions Eu(III) and Tb(III)].

Two coordination compounds formed between Eu(III) and Tb(III) with ofloxacin have been synthesized. Molecular formula Ln(oflo)3Cl3.8H2O has been deduced from elemental chemical analysis and ICP.FTIR spectroscopy shows that both carbonyl and carboxy groups may coordinate the lanthanide cation(Eu3+/Tb3+) to form a stable six-membered ring. The reaction between lanthanide and ofloxacin can be accomplished without any additional base since FTIR suggests the proton transportation from the carboxyl group to the tertiary nitrogen. The complex containing Eu3+ was proved to be excited with the broad band from 200 to 450 nm. Between the two complexes is studied, Eu3+ is the most efficiently sensitized by ofloxacin, while Tb3+ is the least. The disappearance of the ligand fluorescence and the strong emitting of Eu3+ in the complex, which is ascribed to the transitions 5D0-7F0, 5D0-7F1, 5D0-7F2 respectively, make it clear that some well energy transfer has happened. But complex Tb(oflo)3Cl3.8H2O irradiates lights from both ligand and Tb3+.

Anti-Infective Agents↗