ABSTRACT
Two p-phenylenediamine (p-PD)-imprinted polymers, P (MAA) and P (AA), were synthesized using methacrylic acid (MAA) and acrylamide(AA) as functional monomer, respectively, in order to prepare molecular recognition material with high selectivity for p-PD and explore the feasibility of methods such as molecular spectrometry and computational approach of quantum chemistry for the selection of functional mono mer with high imprinting efficiency.The molecular recognition properties of the imprinted polymers were evaluated by high performance liquid chromatography.The results indicated that P(AA) exhibited no imprint ing effect for p-PD, while P(MAA) can bind p-PD selectively(k' =3.57), which showed remarkable imprint ing effect (IF=2.95), and p-PD and its analogues o-phenylenediamine and p-aminobenzoic acid can almost realize baseline separation on P (MAA) column in the mobile phase of methanol.Furthermore, we made a comparative study on the interaction of p-PD with MAA and AA by spectroscopic techniques such as UV and fluorometry as well as HF/6-31G~* computational approach.The results demonstrated that the complex of p-PD-MAA was more stable than that of p-PD-AA, which can give a good explanation for the molecular recog nition properties of P (MAA) and P (AA).The study indicated that both molecular spectrometry (UV and fluorometry)and computational approach of quantum chemistry can be employed as efficient means for the selection of efficient functional monomer.The results showed that fluorometry is sensitive and convenient for the choice of functional monomer if the template molecule is fluorescent.
ABSTRACT
BACKGROUND: Neonatal hypoxic ischemic encephalopahty(NHIE) is a common neonatal disease, which could cause cerebral palsy, inferior intelligence and convulsion. At present, usual examinations for this disease are CT.MRI and single photon emission computed tomography(SPECT), etc.OBJECTIVE: To investigate the character of SPECT image of NHIE, and compared with CT and MRI as well to provide a theoretical gist for function surveillance and early intervention of NHIE.DESIGN: An observatory comparative study based on NHIE patients and normal neouates as control.SETTING: Department of nuclear medicine in a medical university hospital.PARTICIPANTS: Thirty neonates hospitalized in the Department of Pediatrics, Affiliated Hospital of Jining Medical College between September 1998 and October 2000 were selected as observation group with 23 males and 7 females. Another 10 normal neonates including 7 males and 3 females were randomly selected from same period into control group.METHODS: SPECT brain blood perfusion was conducted in the subjects of two groups and the results were compared with that of CT and MRI.MAIN OUTCOME MEASURES: ① comparison of SPECT brain blood image features between NHIE and normal neonates; ② comparison of SPECT images and CT, MRI results. RESULTS: In 22 NHIE cases who received SPECT, CT and MRI simultaneously, mild group had 7 cases, and positive cases of SPECT, CT or MRI was 7, 3 or 5; moderate group had 10 cases, and positive cases of three methods was 10, 8 or 9; severe group had 5 cases, the all of them were positive in all three examinations. The total positive detectable rate of SPECT, CT or MRI was 100, 72.73% or 86. 36%. There was no significant difference of sensitivity between SPECT and MRI in mild group, while there was significant difference between SPECT and CT(x2 = 3.95, P ＜ 0.05);there was no significant difference among three methods in either moderate group or severe group(x2 =0. 83, P ＞ 0.05).CONCLUSION: SPECT brain blood perfusion image is a quite sensitive method for the surveillance of NHIE, which can provide imageological reference for the evaluation of its prognosis and early intervention.