Simultaneous Probing of Metabolism and Oxygenation of Tumors In Vivo Using FLIM of NAD(P)H and PLIM of a New Polymeric Ir(III) Oxygen Sensor

Tumor cells are well adapted to grow in conditions of variable oxygen supply and hypoxia by switching between different metabolic pathways. However, the regulatory effect of oxygen on metabolism and its contribution to the metabolic heterogeneity of tumors have not been fully explored. In this study, we develop a methodology for the simultaneous analysis of cellular metabolic status, using the fluorescence lifetime imaging microscopy (FLIM) of metabolic cofactor NAD(P)H, and oxygen level, using the phosphorescence lifetime imaging (PLIM) of a new polymeric Ir(III)-based sensor (PIr3) in tumors in vivo. The sensor, derived from a polynorbornene and cyclometalated iridium(III) complex, exhibits the oxygen-dependent quenching of phosphorescence with a 40% longer lifetime in degassed compared to aerated solutions. In vitro, hypoxia resulted in a correlative increase in PIr3 phosphorescence lifetime and free (glycolytic) NAD(P)H fraction in cells. In vivo, mouse tumors demonstrated a high degree of cellular-level heterogeneity of both metabolic and oxygen states, and a lower dependence of metabolism on oxygen than cells in vitro. The small tumors were hypoxic, while the advanced tumors contained areas of normoxia and hypoxia, which was consistent with the pimonidazole assay and angiographic imaging. Dual FLIM/PLIM metabolic/oxygen imaging will be valuable in preclinical investigations into the effects of hypoxia on metabolic aspects of tumor progression and treatment response.     

氧化铟纳米棒的气敏特性

以非离子表面活性剂烷基苯酚聚氧乙烯醚OP-10为形貌控制剂合成In2O3纳米棒.用热重-差示扫描量热法、X射线衍射和透射电镜对In2O3纳米棒的热分解过程、晶体结构和微观形貌进行表征.对纳米棒制得的气敏元件进行气敏性能测试,同时用扫描电子显微镜及比表面积和孔隙度分析仪对元件的表面形貌和材料的介孔结构进行了分析.结果表明:制得的In2O3为立方晶型的纳米棒,直径约20 nm,长度约120 nm.与In2O3纳米颗粒气敏性能相比,In2O3 纳米棒对三甲胺具有更高的灵敏度和选择性.用In2O3纳米棒制的气敏元件对三甲胺在一定的浓度范围内的灵敏度与浓度呈现良好的双对数线性关系.棒状材料中形成的大量介孔对气敏性能的提高有着重要的作用.     

三嗪系列阻燃剂与氧化锑配合对丙烯酸系树脂的阻燃化研究

系统地研究了三嗪系列阻燃剂三烯丙基异三聚氰酸酯(TAIC)、二烯丙基溴丙基异三聚氰酸酯(DABC)、二(2,3-二溴丙基)烯丙基异三聚氰酸酯(DBAC)、三(2,3-二溴丙基)异三聚氰酸酯(TBC)等阻燃剂与三氧化二锑(Sb2O3)配合对丙烯酸系树脂的阻燃效果及其阻燃机理。氧指数(LOI)、热失重(TGA)、微分热失重(DTG)等研究表明,溴值低的DBAC、TBC和Sb2O3有协效作用,符合一般的卤-锑协同阻燃机理;而溴值高的TAIC、DABC和Sb2O3不但不具有协同效应,而且恶化原阻燃剂的阻燃效果;Sb2O3及其与三嗪系列阻燃剂配合阻燃丙烯酸系树脂,主要是发挥气相阻燃作用。     

双层电解质极限电流型氧传感器的制备及其性能

以LaNi0.6Fe0.4O3-δ(LNF)为致密扩散层材料,以8YSZ(8mol％ Y2O3+ ZrO2)和Ce0.9Gd0.1O1.95(GDC)为固体电解质材料,采用共压-共烧法制备了双层电解质型致密扩散障极限电流氧传感器,研究了氧含量和温度对氧传感器氧敏性能的影响.实验结果表明:氧传感器在800～820℃温度范围,氧含量在0.3％～1.2％气氛下,显示出良好的极限电流平台,氧传感器的响应时间和恢复时间分别约为35 s和45 s.极限电流与氧浓度ψ(O2)之间存在较好的线性关系,并且氧传感器log(IL·T)-1/T曲线线性相关.     

氯丙烯环氧化反应器气相安全控制条件

在相转移法氯丙烯环氧化反应过程中,由于少量双氧水发生无效分解生成氧气,导致反应器气相存在燃爆危险性。测试了工况条件下氯丙烯-氧-氮三元体系的燃爆特性,得出该体系的极限氧浓度值(LOC)为10.9%;考察了主要因素对气相氧浓度的影响。研究发现,要降低气相氧浓度,应尽可能降低催化剂用量,适当提高搅拌速度,严格控制H_2O_2用量;应在液相沸腾后开始H_2O_2进料,并控制反应初始阶段的H_2O_2进料量,以避免瞬间H_2O_2进料过快。     

基于冶金热力学的钢液定氧探头氧浓度单位确定

对比分析了以上海贺利氏电测骑士有限公司生产的Celox钢液定氧探头测量的氧活度和文献中报道的氧活度、LF精炼过程中基于[Al]-[O]平衡计算的铝镇定钢液的氧活度及顶底复吹转炉冶炼终点基于[C]-[O]平衡计算的氧活度. 结果表明,该探头测量的氧活度是以1%溶液为标准态,百万分之一氧([10-6 O])为浓度单位,而不是冶金热力学中以氧的质量百分含量([%O])为浓度单位定义的氧活度. 因此,选用氧的质量百分含量[%O]时,Celox钢液定氧探头测量的氧活度量纲应为10-4,而不是其探头仪表显示的10-6.     

Process and fiber spinning studies for the cellulose/paraformaldehyde/dimethyl sulfoxide system

A cellulose pulp of about 550 D.P. was readily dissolved in a combination of (CH₂O)x/DMSO to afford an initial 6/6/88 cellulose/(CH₂O)x/DMSO composition solution. The concentration of formaldehyde was found to be a function of solution heating time and temperature. The solutions were microscopically free of gels and undissolved cellulose fibers. Cellulosic articles such as fibers and films are easily regenerated from these cellulose solutions in the presence of coagulants such as methanol or water. Fibers with high wet modulus, intermediate tenacity, and low elongations were produced from these regenerations systems. Fibers have been spun with conditioned and wet tenacities as high as 2.9 and 2.1 g/d, respectively, with wet modulus (at 5% elongation) as high as 1.3 g/d and solubility in 6.5% NaOH in the low range of 3.0%–15%. In many respects, these fibers are comparable to those produced in the viscose process. However, the low elongations of these fibers probably would not permit normal textile processing. The cellulose/(CH₂O)x/DMSO solutions were modified with compounds containing reactive N? H functional groups which are known to react with excess formaldehyde to yield the corresponding N-methylol derivatives. However, the resulting fiber physical properties were not significantly improved compared to those obtained from unmodified cellulose solutions. Addition of acrylic acid derivatives such as methyl acrylate, butyl methacrylate, or acrylonitrile to the cellulose solutions did not result in the formation of the expected 1,4-type adducts.     

几种血卟啉3,8—烷氧（硫）基衍生物产生单重态氧能力的研究

在“血卟啉衍生物”(HPD)肿瘤光动力疗法取得令人瞩目成就的同时,化学家们证明了临床使用的HPD制剂并非原意义上的血卟啉衍生物,而是一种复杂的卟啉混合物,其中血卟啉(HP),羟乙基-乙烯基-次卟啉(HVD),原卟啉(PP)约占总量的80％,Dougherty等分离得到其余20％未知结构羧基卟啉,认为此为HPD的有效成分,经进一步分析测定其主要成分是二血卟啉醚(DHE)。但最近的工作又表明,全合成得到的DHE与HPD有效成分的化学组成及生物活性亦不相同。显然这类药物组分复杂、结构的不确定限制了肿瘤光动力疗法的进一步发展。近年来,人们正试图从已知结构的化合物中探索新的光敏药物,作者在合成出一系列结构确定的单一组分血卟啉     

ZnFe2O4高温煤气脱硫剂的再生

在热天平上对自制的ZnFe2O4脱硫剂进行了再生工艺研究，考察了再生温度、O2浓度对ZnFe2O4脱硫剂再生性能的影响；进行了多次硫化、再生循环实验，并与加入玻璃粉的样品进行了比较。结果表明，700℃下氧含量2.0%(vol)时再生可以获得良好的再生率和二次硫化反应活性；玻璃粉的少量加入，会改善脱硫剂长期使用的稳定性，但反应活性有所下降。     

Novel porphyrin‐grafted poly(phenylene vinylene) derivatives: Synthesis and photovoltaic properties

A series of novel porphyrin‐grafted poly (phenylene vinylene) derivatives, Porp‐RO‐PPV, were synthesized by a simple two‐step method. These copolymers contain conjugated poly(phenylene vinylene) derivatives as polymer backbone and covalently linked porphyrin units as side chain, which were confirmed by FTIR and ¹H NMR, and used for photovoltaic devices. The thermal, optical properties and sensitizing effect, and photovoltaic properties have been investigated. The emission spectra of Porp‐RO‐PPV copolymers revealed the existence of strong energy transfer from PPV backbone to porphyrin units. The energy conversion efficiency (η_e) of photovoltaic devices based on Porp‐RO‐PPV+PCBM reached 0.33% (78.2 mW/cm², AM1.5) and porphyrin units in the copolymers showed good sensitizing effect at low concentration. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

氧化铜与二氧化硫及氧作用生成硫酸铜的动力学

在不同温度及气相组成下,曾对氧化铜与SO_2及O_2作用生成硫酸铜的动力学进行了研究。 反应先生成盐基性硫酸铜,然后再生成硫酸铜。俟硫酸铜生成量达30％后,形成一硬壳,此时反应为气体通过硬壳层的扩散所控制。 当反应仅生成盐基性硫酸铜时,盐基性硫酸铜生成的百分数f_b=a+b_t;t为时间,a及b为常数。生成硫酸铜时,硫酸铜的最初生成百分数f_c=kt。俟硬壳形成后,反应即减慢。 在硬壳未形成之前,生成盐基性硫酸铜及硫酸铜的速度均可用下式表示: R_(av)=(k_1·PSO_2)/(1+k_2·(PO_2)~(1/2)+k_3·PSO_2) 式中R_(av)为时间平均反应速度,PSO_2及PO_2分别为SO_2及O_2的分压,k_1、k_2及k_3为常数。实验结果推论出反应为表面上氧离子上吸附的SO_2进一步作用为SO_4~(-2)的速度所控制。当气相中没有氧存在时,反应结果尚生成氧化亚铜。由于氧化亚铜系p-型半导体,因此反应较有氧气存在时为快。当气相中有SO_3存在时,反应速度较仅有SO_2及O_2存在时为快。在此种情况下,反应机理估计与目前结论完全不同。     

Injectable,dispersible polysulfone-polysulfone core-shell particles for optical oxygen sensing

Injectable sensors can significantly improve the volume of critical biomedical information emerging from the human body in response to injury or disease. Optical oxygen sensors with rapid response times can be achieved by incorporating oxygen-sensitive luminescent molecules within polymeric matrices with suitably high surface area to volume ratios. In this work, electrospraying utilizes these advances to produce conveniently injectable, oxygen sensing particles made up of a core-shell polysulfone-polysulfone structure containing a phosphorescent oxygen-sensitive palladium porphyrin species within the core. Particle morphology is highly dependent on solvent identity and electrospraying parameters; DMF offers the best potential for the creation of uniform, sub-micron particles. Total internal reflection fluorescence microscopy confirms the existence of both core-shell structure and oxygen sensitivity. The dissolved oxygen response time is rapid (<0.30 s), ideal for continuous real-time monitoring of oxygen concentration. The incorporation of Pluronic F-127 surfactant enables efficient dispersion; selection of an appropriate electrospraying solvent (DMF) yields particles readily injected even through a < 100 μm diameter needle.     

Methanol-tolerant electrocatalysts for oxygen reduction in a polymer electrolyte membrane fuel cell

Heat-treated -oxo-iron(iii) tetramethoxy phenyl porphyrin (Fe-TMPP)2O and iron(iii) tetramethoxy phenyl porphyrin (FeTMPP-Cl) as well as iron(iii) octaethyl porphyrin (FeOEP-Cl) adsorbed on high-area carbons such as deashed and un-deashed RB carbon (Calgon) and Black Pearls-2000 (Cabot) have been found to exhibit stable and very high oxygen reduction rates. Experiments done over a period of 24h showed no performance degradation. Measured performances were very similar to supported platinum (E-Tek), when tested in 85% H3PO4-equilibrated Nafion 117 membrane at 125°C and hydrated-Nafion membrane at 60°C in a minifuel cell. The macrocycle cathodes are insensitive to the presence of methanol whereas the platinum cathodes are very sensitive and show degradation in the oxygen reduction performance.     

金属卟啉仿生催化制备环氧丙烷

制备了四苯基卟啉、四-4-甲氧基苯基卟啉、四-4-氟苯基卟啉及3种卟啉相对应的钴、锰、铁金属卟啉,并利用Cary紫外可见分光光度计(UV-vis)和傅里叶变换红外光谱仪(FTIR)对金属卟啉进行了表征;以制备的不同金属卟啉为催化剂,丙烯为原料,氧气为氧化剂,仿生催化丙烯氧化合成环氧丙烷。考察了金属卟啉催化剂类型、金属卟啉催化剂浓度、反应压力、反应温度、反应时间对反应的影响,结果发现上述因素对反应收率、转化率、选择性均有显著影响,且都有一个最佳值,获得的最优化反应条件为:选取四-4-氟苯基铁卟啉为催化剂,催化剂浓度为1.35×10^-5mol/L,反应压力1.75MPa,反应温度100℃,反应时间为2h。在最优化的反应条件下,环氧丙烷的收率达到了40.38%,丙烯转化率达到了47.09%,环氧丙烷选择性达到了85.75%。     

H_2O_2/O_3催化氧化改性活性炭研究

采用H2O2/O3催化氧化改性活性炭。以含氧官能团总量为主要指标、比表面积和碘吸附值为辅助指标评价改性效果。在活性炭质量和H2O2体积一定的条件下,考察了H2O2质量分数、O3浓度、反应时间及反应温度等因素对活性炭性能的影响。在H2O2质量分数为10%、O3浓度为4.32 mg.L-1、反应时间为2.5 h、反应温度为50℃的最优改性条件下,活性炭的含氧官能团总量为1.525 mmol.g-1,比改性前提高61.38%。     

Photovoltaic Study of Photoelectrochemical Biofuel Cells Sensitized by Porphyrin Derivatives with Different Substituents

Two porphyrin derivatives with different substituents were investigated as dyes for the titanium dioxide (TiO₂) film electrode to construct new two-compartment photoelectrochemical biofuel cells (PEBFCs). The two porphyrin derivatives were tetrakis(4-carboxyphenyl)porphyrin (TCPP) and meso-tetra(p-hydroxyphenyl)porphine (THPP). To determine how cell performance was affected by the dye with different substituents, we analyzed the photochemical and photoelectrochemical properties of the two dyes by physical characterization and photoelectrochemical experiments. The UV–Vis absorption spectra and X-ray photoelectron spectra indicated that the interactions between the dye and TiO₂ decreased in the order of TCPP > THPP, which was also in accord with the results of Fourier transform infrared. In addition, TCPP and THPP were calculated using the density functional theory and the time-dependent density functional theory, and the calculation result exhibited that the radiative lifetime decreased in the order of TCPP > THPP. Compared with THPP, TCPP with longer excited-state was expected to enhance the performance of a PEBFC. We measured and compared the incident photon-to-collected electron conversion efficiency and the light-to-electrical conversion efficiency (η) of the porphyrin-sensitized photoelectrochemical biofuel cell. The photovoltaic characteristics showed the TCPP was more effective compared to the THPP, which obviously showed that the experimental results were consistent with theoretical expectation. These results revealed that the kind of the substituent for the porphyrin influenced the photovoltaic properties of the PEBFC.     

Electrocatalysis of the Reduction of Dioxygen by π-Conjugated Polymer Complexes with Dinuclear Cobalt Porphyrin

Catalysis of polymer complexes using polyanilines and dinuclear cobalt porphyrin (Co₂P) was investigated by electrochemical measurement. Poly(2,3-dicarboxyaniline) with CoTPPS–CoTMPyP acts as an excellent catalyst for a four-electron reduction of oxygen even under pseudo-neutral conditions. Various polymer complexes were made using synthesized electroresponsive polymers. The selectivity of the four-electron reduction dramatically decreases with an increase in the potential gap between the polymer and the porphyrin. This result indicates that a sequential electron transfer takes place from the polymer to the porphyrin with a potential similar to that of the cobalt porphyrin.     

铁-锌卟啉框架材料及其可见光催化降解罗丹明B

以5,10,15,20-四-(4-羧基苯基)锌卟啉(ZnTCPP)为配体，以金属Fe为节点构筑了具有三维网状结构的铁-锌卟啉框架材料PCN-600(Zn)，采用PXRD、SEM、UV-vis DRS对所得材料进行了表征，并将其用于可见光下罗丹明B(RhB)的降解反应，考察了H2O2浓度对PCN-600(Zn)光催化性能的影响，并通过捕获实验确定了光催化反应过程中的主要活性物种，对比了PCN-600(Zn)与另一种锆-锌卟啉框架材料PCN-222(Zn)的光催化性能。结果表明，在H2O2的协同作用下，PCN-600(Zn)对RhB的降解表现出显著的催化活性，可见光照射90分钟后降解率可达94.2%，在实验范围内，随着H2O2浓度的增加，PCN-600(Zn)的催化活性不断提高，H2O2用量为4 mL时可最大程度上提升催化剂效率；实验证明在催化过程中，空穴（h+）为主要活性中间体，·OH 和·O2-也起到了一定的作用。此外，PCN-600(Zn)的光催化性能明显强于PCN-222(Zn)，相同实验条件下，前者罗丹明B的降解率可达95.9%，后者仅达67.6%。     

辣根过氧化物酶催化合成水溶性导电聚苯胺的研究

以辣根过氧化物酶(HRP)为催化剂、十二烷基硫酸钠(SDS)为模板研究了生物催化水溶性导电聚苯胺(PANI)的合成.探讨了反应体系的pH值、过氧化氢浓度和SDS浓度对聚合反应的影响,并研究了HRP催化苯胺聚合过程中性质的变化.紫外可见扫描光谱分析和电导率测定的结果表明,在以SDS为模板的条件下,HRP催化水溶性导电聚苯...     

助剂钾对 V2O5-Ag2O催化氧化甲苯制苯甲醛的研究

制备了 V2O5- Ag2O- K2O/Al2O3- MgO和 V2O5- Ag2O- K2O/Al2O3- USY用于甲苯气相催化氧化制苯甲醛,研究助剂 K对催化剂作用的影响,研究表明 K有助于降低亲电子氧( O-、O2-)的含量,而亲电子氧是甲苯过度氧化的氧源,同时也阻止甲苯上甲基的断裂;提高甲苯氧化的选择性,阻止甲苯上甲基的断裂,使苯的生成减少. K有助于亲核氧( O2-)的生成,加快催化氧化过程. X衍射图谱分析表明,过量 K易形成无活性的 KVO3,不利于催化过程.