生物医用玻璃的活性及其临床应用

通过对活性度的表征，探讨了生物玻璃的活性机理，综合评述了生物玻璃在组织(如牙齿和骨等)的填充、器官损伤修复及癌症的治疗等方面的广泛临床应用。     

CeO2紫外吸收光谱蓝移机理研究进展

本文简要概述了近年来国内外学者关于CeO2蓝移现象起源的研究成果,主要包括量子尺寸效应,Ce3+和Ce4+间价态转变、稀土离子掺杂、由电子-声子耦合产生的界面极子效应等原因。这对研究CeO2的紫外吸收性能具有十分重要的作用。     

水解度对溶胶-凝胶生物玻璃生物活性的影响

为了获得具有较高生物活性和良好生物矿化性能的生物活性材料,以正硅酸乙酯(TEOS)及磷酸三乙酯(TEP)为前驱体,硝酸钙(CN)为添加剂,盐酸为催化剂,在不同水与醇盐物质的量比(R)条件下,采用溶胶-凝胶法制备了CaO-P2O5-SiO2系统生物活性玻璃.利用生物活性材料的体外评价方法及FTIR、XRD、SEM测试技术对样品的结构和生物活性进行了分析研究.结果表明:经模拟体液(SBF)浸泡后, 随着水解度的增大,其表面羟基磷灰石层的形成能力逐渐减弱.     

纳米CeO2的紫外吸收和表面改性研究

紫外吸收光谱分析氨水沉淀法制备的粒度在10nm的纳米二氧化铈表明在200～480nm的范围具有较好的紫外吸收能力。用无水乙醇为溶剂,硬脂酸为改性剂,初步探讨了纳米CeO2进行表面改性机理。活化度和吸油值分析表明,当硬脂酸用量在2．5％时,已经有较好改性效果,为纳米CeO2在聚合物中的应用提供一定的参考价值。     

Effect of CoO and Gamma Irradiation on the Infrared Absorption Spectra of Lithium Borate Glasses

Undoped and cobalt-doped lithium borate glasses (LBG) of various compositions, by varying cobalt contents were prepared by a conventional melt quenching technique. The density and molar volumes of the glass samples were estimated and; infrared absorption spectra were measured in the spectral range 400–1600 cm^?1before and after an irradiation dose of 50 kGy and 200 kGy. Experimental results showed that the density of studied samples increased as CoO increased while the molar volume decreased. FT-IR spectra of the prepared samples have been analyzed by the deconvolution of the spectra. A deconvolution technique is presented to make use of the BO₄ data and follow the change in the modifier and former fractions of CoO. FTIR was also used to study the glass system before and after gamma irradiation. The experimental results clearly indicate that after irradiation a significant change in the structure of the LBG glass network is observed. The modifying action of CoO on the glass composition is also studied. The glasses doped with 5 wt% of CoO are relatively more radiation resistant than the other compositions.     

Effect of Gamma Radiation on Optical and EPR Absorption Spectra of Phosphate and Fluoride Glasses Containing Lead

The induced optical and EPR absorption spectra of phosphate and fluoride glasses containing lead are investigated. It is revealed that exposure to gamma radiation leads to the formation of radiation-induced defects responsible for the induced absorption band with a maximum at 12500–13500 cm⁻¹ and the EPR signal in the form of an almost symmetric line with a g factor of 1.999 and a linewidth of ≈26 Oe. Analysis of the intensities of the absorption bands and the EPR signals in the spectra of glasses with low terbium, tin, and carbon contents and the study of their thermal bleaching demonstrate that the color centers are electron traps, whereas the paramagnetic centers are hole-trapping centers. Examination of the change in the parameters of the absorption bands in the spectra of glasses with different R ₂O contents (R = Na, K, Rb, Cs) makes it possible to determine the location of the color centers associated with the Pb⁺ ions in the structure. It is established that the glasses under investigation are characterized by the nonlinear absorption of radiation at a wavelength of 1.06 μm. The mechanism of formation of radiation-induced defects is considered. Original Russian Text Copyright ? 2005 by Fizika i Khimiya Stekla, Bocharova, Karapetyan.     

Optical Absorption and EPR Studies on Gamma-Ray Irradiated RE<Superscript>3+</Superscript>-Doped Fluorophosphate Glasses

We have studied the effect of γ-ray irradiation on optical absorption, emission and decay characteristics of RE³⁺ (RE?=?Sm, Eu and Dy)-doped fluorophosphate glasses. Electron paramagnetic resonance (EPR) study confirms the POHC and PO₃ EC defects induced in glasses by the γ-irradiation. The presence of induced defect centers significantly affects the optical and emission properties. The optical band gap values of the studied systems increased after the γ-ray irradiation. The phonon energy and electron–phonon coupling strength of Eu³⁺-doped fluorophosphate glass were determined from the phonon sideband analysis. The emission intensity of the RE³⁺ ions increased significantly after the γ-ray irradiation. The intensity parameter, R is the ratio of the intensities of the ⁵D₀ → ⁷F₂/⁵D₀ → ⁷F₁ transitions of Eu³⁺ ion and Y/B intensity parameter is the ratio of intensities of the ⁴F_9/2 → ⁶H_13∕2/⁴F_9/2 → ⁶H_15/2 transitions of Dy³⁺ ion reveal that the local environment around the RE³⁺ ion changed after the γ-ray irradiation in the present system. The lifetime of excited states of RE³⁺ ions decreased after the γ-ray irradiation due to the formation of defects induced by the γ-ray irradiation. The CIE color coordinates were determined before and after the γ-ray irradiation for the Dy³⁺-doped glass system.     

纳米CeO2悬浮液的流变性能研究

在化学机械抛光过程中,抛光液的流变性能起到至关重要的作用。本文利用Haake流变仪研究了水基纳米CeO2悬浮液在不同pH值、CeO2颗粒浓度、温度、中性电解质浓度下的流变性能。研究结果表明,随着zeta电位减小,悬浮液表观粘度增大,体系逐渐转变为剪切变稀的非牛顿流体。悬浮液中CeO2颗粒浓度低于17.4wt%时,颗粒浓度对体系的流变性能影响较弱,体系为牛顿流体,但是继续增大颗粒浓度,悬浮体表观粘度明显增大,出现剪稀现象。温度对悬浮液流变性能影响较为复杂,当温度小于35℃时,随着温度的升高体系表观粘度变小,温度大于35℃时,温度的升高反而使体系表观粘度增高。中性电解质的加入使得悬浮体的zeta电位降低,从而使体系表现出较高的表观粘度。     

Optical Absorption Spectra of Chlorine-Associated Defect Centers in an Irradiated ZrF4-Based Glass

The optical absorption spectra of an irradiated zirconium-barium-lanthanum aluminum- lithium fluoride glass prepared with 1 wt% BaC12 were resolved into Gaussian bands identified as the V_k, and V_H centers, Zr³⁺, and two bands associated with Cl, i.e., FCl⁻ at 4.78 eV and Cl⁻₂ at 3.90 eV. These latter bands are more thermally stable than the VH and V, trapped hole centers, persisting to 450 and 550 K, respectively.     

Stable and Transient Spectra in Pulse Irradiated Metaphosphate Glasses

Pulse radiolysis of pure metaphosphate glasses yields a transient spectrum with a maximum at 580 run. This new absorption overlaps that of the permanent coloration at 500nm. The decay of the 580nm species extends over a very large time interval, from ～10^?7 sec to ～10^?2 sec. The effects of doping the glass with CdSO₄ and Ce₂(SO₄)₃ are reported and analyzed. The results are interpreted in terms of various electron and hole centers. It is suggested that non homogeneous (spur or cage) kinetics is responsible for the 580 nm decay.     

Absorption and Fluorescence Spectra of Nitrobenzanthrones

To identify nitrobenzanthrones (NBAs) such as 3-nitro-7 H -benz[ de ]anthracene-7-one (3-NBA) on the basis of their electronic spectral data, we have synthesized 1-, 2-, 3-, 9-, and 10-NBAs and measured their absorption and emission spectra. The first strong absorption band of the NBAs appeared in the region 350-440 nm; the band of 10-NBA was red-shifted by about 20 nm. The molar absorptivities of 3- and 9-NBA were about two times as large as those of the others. The fluorescence spectra of the NBAs varied more largely with the position of the nitro group compared to the absorption spectra. The quantum yields of fluorescence were very small, ranging from ～10 m 2 for 2- and 10-NBA to ～10 m 4 for 1- and 3-NBA. 3-NBA exhibited a characteristic spectrum with two broad bands at 450 and 530 nm. On excitation causing an n ~ * transition in the NBAs, their fluorescence intensities increased by a factor of 10. Phosphorescence was observed at 77 K for all compounds though that of 1-NBA was very weak. These results give the promise of characterizing individual isomers of NBAs on the basis of their spectroscopic data.     

形貌对CeO2纳米颗粒紫外吸收性能的影响

以Ce(NO3)3·6HO和NaOH为原料,采用水热合成法制备了不同晶粒尺寸、形貌各异(球形、棒状、立方体等)的纳米CeO2产物.XRD测试表明所得产物为立方萤石晶型结构.紫外吸收光谱表明:对于球形颗粒CeO2,晶粒尺寸越小,紫外吸收能力越强.颗粒形貌对纳米CeO2紫外吸收能力有较大的影响,在紫外光区吸收能力:纳米棒＞纳米立方体＞纳米球形.研究发现形貌对紫外吸收能力影响与其纳米颗粒的暴露晶面的表面能有关,暴露晶面的表面能越高,紫外吸收能力越强.     

Characterization of Gamma Irradiated PEs using ESR,FTIR and DSC Techniques

Summary We study the effects of -rays on different PEs using the ESR, FTIR and DSC. The changes in the ESR and FTIR spectra after irradiation is studied. We found that the chemical reactions produced during radiation as well as during the storage time are mainly scission and crosslinking and/or branching. The percentage of each of these reactions was determined by the Charlesby-Pinner equation and we concluded that they depend on the linearity of the PE.     

碘化铅对Dy3+掺杂GeS2-Ga2S3玻璃荧光光谱性质的影响

采用熔融淬冷法制备了掺杂浓度为0.3%(质量分数)的Dy3+:(100–x)(0.8GeS2–0.2Ga2S3)–xPbI2(x=5,10,15,摩尔比)系列硫卤玻璃样品,测试了样品热稳定性、折射率、密度、吸收光谱、近红外及中红外荧光光谱。应用Judd–Ofelt理论计算了Dy3+在系列样品中的强度参数(Ωt,t=2,4,6)、自发辐射跃迁几率、荧光分支比以及辐射寿命等光谱参数。讨论了PbI2含量对样品的吸收光谱、光谱参数以及荧光光谱的影响。在Dy3+掺杂样品中,PbI2含量的增加有效地提高了1 330 nm和2 860 nm处的荧光强度。计算了0.3%Dy3+掺杂68GeS2–17Ga2S3–15PbI2玻璃在1 330 nm和2 860 nm处的受激发射截面值分别为3.63×10–20 cm2和1.57×10–20 cm2,2 860 nm处的量子效率为83.8%。     

Absorption Spectra of Some Phenothiazinequinonoid Dyes

Phenothiainquinonoid dyes were found to absorb at much longer wavelengths(50–70 nm) than the corresponding phenoxazinequinone and N, N-dihydrophenzinequinone analogues, and are approximately 100 nm more bathochromic than the corresponding arylaminoanthraquinoid dyes. Several types of phenothiazinequinonoid spectra have been compared with those of the related quinonoid dyes. The effects of the epi-thio group in phenothiazinequinones on their absorption spectra were evaluated by the PPP MO method, and the colour-structure relationships for the related dyes are discussed.     

Absorption Spectra of Cobalt-Tinted Alkali-Borate Glasses

Optical absorption spectra of cobalt-tinted alkali-borate glass in the visible and short IR range (0.4 – 2.7 m) are studied. An attempt is made to establish a relationship between modifications in the structure of the boron-oxygen lattice and transition of cobalt ions from an octahedral coordination to a tetrahedral one.     

Characterization of Gamma Irradiated Ethylene-Norbornene Copolymer using FTIR, UV-Vis and DSC Techniques

Due to their new combination of properties and shortage of the experimental data, the radiolysis of a new class of materials, cyclo-olefin copolymers (COC), which are polymerized from norbornene and ethylene using metallocene catalysts, is of great interest to the study of radiation chemistry and physics of polymeric systems. Ethylene-norbornene copolymer, bare and containing 0.45 wt % of the hindered phenolic type of an antioxidant (IRGANOX 1010) was subjected to gamma irradiation (100, 200 and 500 kGy) in the presence of air and in water. The irradiated copolymer was studied using FTIR, UV-vis spectrophotometric and gel content analysis. The insoluble fraction was formed in copolymer irradiated in water with 500 kGy, in bare 36% and in copolymer with an antioxidant 23%. The radiation induced changes in the molecular structure were correlated to the specific heat capacity and the glass transition temperature measured by DSC method.     

微波辐照煤系高岭土及其吸油性能

以山西煤系高岭土为原料,在1800 W的功率下对3 g煤系高岭土进行微波辐照,以此提高煤系高岭土的吸油值.利用扫描电镜、X射线衍射仪、红外光谱分析仪、比表面积分析仪等对处理前后样品的形貌和结构进行表征.结果表明,随微波辐照时间的增加,煤系高岭土的吸油值呈先增加后降低的趋势,且在处理时间为17.5 min(最高温度达到1...     

Radioprotectant Activity of 5-Diethylsulfonamoylsalicylatocopper(II) in Gamma Irradiated Mice

Survival and changes in mean body mass of whole-body irradiated mice were determined to examine the radioprotectant activity of 5-diethylsulfonamoylsalicylatocopper(II) [Cu(II) (5-DESS)]. One of four groups of 25 female C57BL/6 mice were treated subcutaneously (sc)with 0, 10, 20, 40, 60, 80, 100, or 120 mumol Cu(II)(5- DESS)/kg of body mass 3 hours before exposure to 8.0 Gy, gamma irradiation. In this paradigm, doses of Cu(II)(5- DESS) increased survival up to 92% above vehicle-treated control mice (P = 0.008). Mean body mass determinations revealed that mice treated with 80 to 120 mumol Cu(II)(5-DESS)/kg of body mass exhibited a smaller decrease in body mass than other complex-treated groups. These results support the hypothesis that Cu(II)(5-DESS) is an effective radioprotectant.