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1.
Abstract— The authors performed photodynamic therapy (PDT), avoiding any hyperthermic effects, using a newly developed diode laser and photosensitizer, mono-L-aspar-tyl chlorin e6 (NPe6), of Meth-A fibrosarcoma implanted in mice and achieved tumor therapeutic benefit. The photodynamic light treatment was performed 5 h following the photosensitizer administration. With 5.0 mg/kg NPe6 and light doses of 50, 100, 150 and 200 J/cm2, the tumor cure rates were 20, 50, 70 and 90%, respectively. With 100 J/cm2 laser exposure and NPe6 doses of 1.25, 2.5, 5.0, 7.5 and 10.0 mg/kg, the tumor cure rates were 0, 20, 50, 70 and 90%, respectively. A charge-coupled device (CCD) camera system was employed to measure the NPe6 fluorescence intensity correlating with the residual amount of the photosensitizer at deferent depth from the tumor surface. The ratios of the NPe6 fluorescence intensity at 3 mm from the tumor surface following 50, 100, 150 and 200 J/cm2 laser exposure to no laser exposure were 0.73, 0.36, 0.22 and 0.16, respectively. With samples sectioned at 1 mm depth, after 50 J/cm2 and the same photosensitizer dose (5 mg/kg) this ratio was 0.19. These results suggest that a certain increase in the tumor tissue level of NPe6 and a certain increase of laser light dose reaching deeper layers of tumor caused an increase in percent cure. In addition, the effectiveness of PDT depends on the total laser dose reaching deeper layers of tumors. Furthermore, the effectiveness of PDT tends to correlate with the amount of NPe6 photobleaching by PDT.  相似文献   

2.
The in vitro cell survival, localization and ultrastructural changes following irradiation were examined in 9L glioma cells sensitized with a new photosensitizer, lysyl chlorin p6 (LCP). In clonogenic assays, LCP was 10–100-fold more phototoxic than photofrin II on a μg/mL basis. Lysyl chlorin p6 uptake was blocked when cells were incubated at 2°C. In view of the chemical properties of LCP, this finding indicates that uptake probably occurred through the endocytic pathway. Fluorescence studies showed LCP localized in a region of the endocytic compartment similar in size, shape and distribution to that labeled by lucifer yellow CH (LY), as well as localizing diffusely throughout the perinuclear cytoplasm. Cells stained with both LY and LCP, however, had distinctly separate regions of staining. Lysyl chlorin p6 localization differed from that of fluorescent probes labeling the mitochondria, Golgi apparatus and endoplasmic reticulum. Ultrastructural changes at both 2 and 30 min after laser irradiation were similar. Mitochondria were often condensed or swollen and also had constrictions and cytoplasmic invaginations. The Golgi apparatus, perinuclear space and rough endoplasmic reticulum (RER) were dilated. These data demonstrate that LCP localizes in a portion of the endosomal compartment, but that morphologic damage initially occurs in the mitochondria, Golgi apparatus and RER.  相似文献   

3.
The behavior of the triphenylmethane dye crystal violet in aqueous solutions containing polyoxyethylene nonionic surfactants was investigated using absorption and fluorescence spectroscopic techniques. The interactions of the dye were examined in micellar media in order to prevent dye aggregation and to ensure maximum dye and surfactant interaction. The relative fluorescence enhancements and the binding constants of the dye to the surfactant micelles were determined. The micropolarities of the micellar environment sensed by the pyrene probe were estimated from the I 1/I 3 intensity ratios of the fluorescence spectra of pyrene. The fluorescence quenching of pyrene by hexadecylpyridinium chloride was investigated in aqueous surfactant mixtures at a fixed concentration of surfactant in order to determine the aggregation numbers. Attempts were made to correlate the binding constants obtained in this investigation to various micellar parameters.  相似文献   

4.
以纳米SiO2水溶胶为原料,3?氨丙基三乙氧基硅烷(APTES)和3?氯丙基三乙氧基硅烷(CPTES)为改性剂,在水基环境下分别对SiO2纳米粒子进行改性,得到了具有亲水特性的APTES改性SiO2粒子和具有亲油特性的CPTES改性SiO2粒子水溶胶。2种粒子按不同比例混合,利用接枝在SiO2粒子表面氨基和氯丙基的取代反应,使得2种具有亲水/亲油特性的改性SiO2纳米粒子偶联,制备了粒径为40~50 nm的哑铃型SiO2纳米粒子。并通过透射电镜(TEM)、傅里叶变换红外光谱(FT?IR)、X射线光电子能谱(XPS)以及动态光散射(DLS)等方法对其进行了系统表征。结果表明,2种粒子成功偶联形成了具有哑铃型结构的水相SiO2纳米粒子,该粒子两面具有不同的亲水性,粒径近似等于APTES改性SiO2粒子和CPTES改性SiO2粒子的粒径之和。  相似文献   

5.
We measured the photosensitivity of an artificial tetranuclear oxo–Mn(IV) complex, [Mn4O6(bpea)4]Br4, which has an adamantane-shaped {Mn4O6}4+ core. Illumination caused changes in the absorption spectrum of the compound consistent with a one-electron reduction in the compound. Bromide appears to be the most probable electron donor in the reaction system. Chemical modification of the cluster appears to destabilize it, predisposing it to reductive degradation. UV light was more efficient than visible light in causing the changes. The data support the suggestion that the natural oxygen-evolving Mn complex is photosensitive and can oxidize components of the oxygen-evolving complex in its excited state causing photoinhibition, and that photostability is an important issue in designing Mn complexes for artificial photosynthesis. Furthermore, light-induced oxidation of bromide by [Mn4O6(bpea)4]4+ may suggest that oxidation of chloride is involved in natural water splitting or has been involved during the evolution of the water-splitting enzyme.  相似文献   

6.
Prismatic crystals of Pb6Li2Ca2(PO4)6 were obtained by solid-state reaction. They were characterized by IR spectroscopy and chemical analyses. The structure as determined by X-ray diffraction study on single crystal revealed that the compound is isostructural to the hexagonal phase Pb8Na2(PO4)6. Crystal data for Pb6Li2Ca2(PO4)6: space group P63/m (No. 176), a=b=9.6790(15) Å, c=7.1130(7), Z=1, R=0.039. In the compound, lithium was found to preferentially occupy the site (I) and the structure is stabilized by interactions between electron lone pairs of lead (II) ions. Electrical conductivity measured in a wide range of temperature is governed by a hopping mechanism of Li ions in tunnels.  相似文献   

7.
采用循环伏安法和计时安培法研究了CuCl2硅溶胶和水溶液中铜在玻碳电极上的电沉积和电结晶行为.结果表明在两种CuCl2电解质中,铜的电沉积分两个步骤完成,Cu2+还原为Cu+在硅溶胶中较水溶液中容易;采用吸附-成核模型解析电流-时间暂态曲线,并确定铜的电结晶机理为扩散控制下的连续成核三维生长(3DP),Cu2+在水溶液中的扩散系数较硅溶胶中的大,但相同电位下在硅溶胶中的饱和成核数密度高于水溶液中.  相似文献   

8.
9.
以水溶性C60和TiO2粒子为前驱体,采用水热法制备了载有C60的锐钛矿型TiO2纳米粒子。应用X射线衍射、透射电子显微镜、红外光谱、紫外-可见漫反射光谱、荧光光谱对产物进行了表征。以对-硝基苯酚为模型污染物研究了产物的光催化活性,结果表明适量负载C60可以提高TiO2纳米粒子的光催化活性,C60起着传输电子、促进TiO2光生载流子分离的作用,且经7次循环使用后对-硝基苯酚的降解效率仍能达到74%。讨论了载有C60的TiO2纳米粒子光催化降解对-硝基苯酚的机理。  相似文献   

10.
The spectroscopic properties of Ln2MoO6:Eu3+ (Ln = La, Gd, Y) compounds were investigated. The differences in the recorded fluorescence spectra are in accord with the different structures. For the La2MoO6:Eu3+ case, the spectrum is compatible with a C2 point site symmetry. It appears that the energy level scheme is connected with the rare earth oxychloride one, so it is possible to determine accurately sets of crystal field parameters simulating the spectrum. For the other compounds, the Eu3+ ions occupy three different point sites. By using the site-selective excitation on the 5D0 level it is possible to identify the energy level scheme characterizing each point site.  相似文献   

11.
A normal coordinate analysis for the AlCl3 · NH3 complex is performed. Calculations for a hypothetical complex with a planar AlCl3 ligand are included. A deviation from planarity is found in the realistic complex. Force fields for free NH3 and AlCl3 molecules are employed in the construction of an initial approximate force field. The theory of kinematic coupling is used to study the frequency shifts from free to complexed ligands. A final force field is developed so as to reproduce exactly a set of observed frequencies from the literature. Calculations on mean amplitudes and perpendicular amplitude correction coefficients are reported.  相似文献   

12.
In this paper, two LiAlH4-NaNH2 samples with LiAlH4 to NaNH2 molar ratio of 1/2 and 2/1 were investigated, respectively. It was observed that both samples evolved 2 equiv H2 in the ball milling process, however, the reaction pathways were different. For the LiAlH4-NaNH2 (1/2) sample, Li3Na(NH2)4 and NaAlH4 were formed through cation exchange between reactants. The NaAlH4 formed further reacts with Li3Na(NH2)4 and NaNH2 to give H2, NaH and LiAlN2H2. For the LiAlH4-NaNH2 (2/1) sample, Li3Na(NH2)4, LiNH2 and NaAlH4 were formed firstly through the same cation exchange process. The resulting LiNH2 reacts with the remaining LiAlH4 and produces H2 and Li2AlNH2.  相似文献   

13.
Mean amplitudes of vibration for the title hexafluoroanions were calculated on the basis of its vibrational-spectroscopic and structural data in the temperature range between 0 and 1000 K. The results are briefly discussed in comparison with those of other related species.  相似文献   

14.
The freezing points of mixtures of benzene, C6H6, with one of its isotopes, C6D6 and 13C6H6, and those of acetic acid CH3COOH with its isotopes, CH3COOD and CD3COOD, were measured as functions of the molal concentrations of C6D6 and 13C6H6, CH3COOD and CD3COOD, respectively. They changed linearly or non-linearly with increasing molal concentration of C6D6 and 13C6H6, CH3COOD, and CD3COOD, respectively. These findings confirm Kiyosawas previous conclusion drawn from experiments on the freezing points of mixtures of H216O with H218O or H217O. This hypothesis states that even a difference in the number of neutrons in the hydrogen or oxygen atoms of water molecules makes water molecules behave as different entities with respect to the colligative properties of solutions. This concept can be extended to mixtures of ordinary benzene with either of its isotopes, C6D6 or 13C6H6, and those of ordinary acetic acid CH3COOH with either of its isotopes, CH3COOD or CD3COOD.  相似文献   

15.
An electronic spectrum of the nickel monoboride radical has been observed for the first time, in a reaction between a nickel plasma and diborane. Numerous bands of 58Ni10B and 58Ni11B have been recorded between 442 and 503 nm in laser-induced fluorescence (LIF). Dispersed fluorescence experiments have also been performed. The LIF spectrum is dominated by a strong progression of bands of a [19.7]2Σ+X2Σ+ transition. Analyses have been carried out to yield the following 58Ni11B ground state parameters: r0 = 0.1698 nm, ωe = 778 cm−1, ωexe = 4.9 cm−1. Strong signals from NiH have also been observed.  相似文献   

16.
采用硅胶负载Keggin型H6PMo9V3O40催化水杨醛与硝酸反应合成5-硝基水杨醛,考察了催化剂负载量、反应时间、反应温度、催化剂用量、硝酸用量和溶剂对反应的影响及催化剂的重复使用性能。实验结果表明,m(水杨醛)∶m(质量分数65%硝酸)∶m(负载量20%H6PMo9V3O40/SiO2)=2.44∶3.00∶3.00,用石油醚作为溶剂,45℃反应2.5 h,水杨醛的转化率为98%,5-硝基水杨醛的选择性为96.8%。催化剂回收容易,重复使用5次后,活性基本不变。  相似文献   

17.
IntroductionWO3has received considerable attention becauseof its photochromic and electrochromic properties[1—10].Since the photochromic process of WO3can be com-pletely reversible by exposing it to oxygen,it has beenconsidered to be one of the most prom…  相似文献   

18.
The dissociation of UF6 sensitized by SF6 excited with a pulsed CO2 laser in the presence of H2 and CO as scavengers has been investigated. In the SF6-UF6-H2 system the dissociation yields have been determined as a function of the laser frequency, the fluence, and H2 partial pressure. A maximum dissociation yield has been found at a laser frequency of 935 cm?1. No obvious dissociation of UF6 was observed in the UF6-SF6 system without F-atom scavengers.  相似文献   

19.
The title reactions were found to proceed in solution with formation of a mixture of the complexes (FeF)SiF6 and (FeF2)2SiF6 with an average atomic ratio F/Fe ? 1.6. Partial reactions involved in equilibria in the reaction system are proposed and discussed.  相似文献   

20.
A wide variety of geometrical structures of NLi6 molecule were studied using HF ab initio and BLYP-DFT techniques. Three stationary configurations which take D4h, D3d and D2d configurations were obtained. Their equilibrium geometries and fundamental frequencies were calculated at HF and BLYP-DFT levels. Among the three stable states, the global minimum prefers D3d configuration, which is different from those of CLi6 and OLi6. The D3d isomer of NLi6 is 3.43 and 28.45 kcal/mol lower in energy than the D4h and D2d ones in the DFT calculation, respectively. All calculations were performed with 6-31G* polarized split-valence basis set.  相似文献   

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