NaYF_4:Yb~(3+),Er~(3+)纳米晶的溶剂热制备及光学性质研究

本文采用溶剂热法制备了Yb~(3+)和Er~(3+)共掺杂NaYF_4上转换发光材料,并对材料的结构、尺寸、形貌及上转换发光性质进行了表征。研究结果表明F-/Y~(3+)的比例对材料结构,形貌及尺寸有着重要影响,较高的F-浓度有利于六角相NaYF_4的生成。由于较小尺寸材料中表面吸附大声子振动基团的增加,增加了~4I_(11/2)-~4I_(13/2)无辐射驰豫速率,红光能级~4F_(9/2)得到有效布居,红光比例相对增强。     

Yb~(3+)/Tm~(3+)共掺Y_2(MoO_4)_3的上转换发光

采用水热法制备了Yb~(3+)/Tm~(3+)共掺Y2(Mo O _4)_3系列上转换发光粉。由于Tm~(3+)在980nm附近没有吸收,单掺Tm~(3+)的样品观测不到任何发射。引入Yb~(3+)后,借助Yb~(3+)对980nm红外光的吸收和Yb~(3+)到Tm~(3+)的能量传递,在可将光区观察到源自Tm~(3+)的蓝光和红光。这两个波段的发射随着Yb~(3+)和Tm~(3+)的浓度增加均呈现先增强后减弱的变化规律,8%和0.5%对应Yb~(3+)和Tm~(3+)的最佳掺杂浓度。上转换发射的功率关系研究表明,蓝、红光均为三光子过程,因此二者的产生过程为连续三步Yb~(3+)到Tm~(3+)的能量传递。     

药物担载体系NaYF_4:Ce~(3+)/Tb~(3+)@mSiO_2球的制备

采用高温溶剂热法制备了NaYF_4:Ce~(3+)/Tb~(3+)球形纳米粒子,并成功合成了NaYF_4:Ce~(3+)/Tb~(3+)@mSiO_2纳米球。     

掺杂Fe~(3+)改性TiO_2光催化降解6-硝废水的研究

染料废水是工业废水的主要来源,其水量大、浓度高、成分复杂、难生化降解,是国内外公认的难处理的工业废水。本研究以钛酸正丁酯为前驱体,采用溶胶-凝胶法制备纳米TiO2,掺杂Fe3+改性纳米TiO2制备催化剂,以6-硝废水为处理对象,对其进行光催化降解。考察了焙烧温度、掺杂Fe3+量、催化剂用量、pH、H2O2用量和反应时间对6-硝废水降解率的影响。结果表明,掺杂Fe3+量为0.100wt%,焙烧温度为500℃时制备出的改性TiO2在其用量为0.300g、H2O2用量为4.0ml、pH值为2、反应1.5h时,6-硝废水的降解率达到86.73%。     

β-NaGdF_4:Ln~(3+)纳米材料的下转换发光性质研究

采用水热法合成了β-NaGdF_4纳米晶体,研究了β-NaGdF_4:Ln~(3+)纳米材料的下转换发光性质。     

LaF_3:Yb~(3+)/Er~(3+)纳米材料的制备及发光性质研究

采用离子热法制备了LaF_3:Yb~(3+)/Er~(3+)纳米材料,研究了LaF_3:Yb~(3+)/Er~(3+)纳米材料的上转换发光性质。     

人参皂苷对免疫抑制小鼠T细胞亚群(CD4+/CD8+)及血清TNF-α含量的影响

为探讨人参皂苷的免疫促进作用,本试验将50只昆系小鼠随机平均分为5组:空白对照组,免疫抑制模型组及免疫抑制小鼠人参皂苷高(0.1 ML/d)、中(0.5 mL/d )、低(1 mL/d )剂量组,免疫抑制小鼠用环磷酰胺腹腔注射(75mg/kg.BW)造模,分别检测小鼠的外周血T细胞亚群(CD4+/CD8+)和血清TNF-α含量的变化情况.结果表明,人参筇苷等对免疫抑制小鼠外周血CD4+/CD8+T琳巴细胞亚群的比例以及小鼠血清TNF-α的含量均有一定的促进和提高作用.     

Fe~(3+)与PrP106-126共同诱导下N2a细胞的氧化应激状态

利用PrP106-126多肽的神经毒性,结合Fe3+对细胞氧化应激可能的诱导作用,建立N2a细胞的氧化应激模型,以研究氧化应激在Prion疾病过程中的作用,及其诱导神经细胞退行性损伤的机制。试验表明,通过毒性多肽PrP106-126与Fe3+共同作用,模拟神经细胞的氧化应激状态是可行的。效果较佳的攻毒浓度和攻毒时间分别是不高于50μmol/L的毒性PrP106-126多肽,不高于500μmol/L的Fe3+,最佳攻毒时间为12h。     

胚胎干细胞分化的重要分子开关:Oct-3/4

POU(Pit-Oct-Unc)域转录因子Oct-3/4已成为小鼠、人、猕猴等哺乳动物体内多能性胚胎干细胞的标志物。在小鼠胚胎发育过程中,Oct-3/4基因只在全能和多能细胞中表达。研究Oct-3/4表达部位及作用机制已成为研究胚胎形成过程及细胞分化过程的必要手段。本文综述了Oct-3/4的表达特性及人、牛、猪、小鼠之间Oct-3/4的结构差异,并详细的描述了其作用机制。     

Binding affinity and capacities for ytterbium(3+) and hafinum(4+) by chemical entities of plant tissue fragments

The binding affinity of ytterbium (Yb3+) and hafinum (Hf4+) to ligands of chemical entities of fragments of bermudagrass tissues and their resistance to exchanging Yb with other ligands and to displacement by protons were investigated. Chemical entities of acid resistant NDF (ARNDF), 0.1 N acid detergent fiber (0.1 N ADF), and permanganate cellulose (CELL) were prepared from fragments of bermudagrass hay (Cynodon dactylon [L.] Pers.) obtained by grinding to pass a 2-mm sieve. 175Ytterbium and Yb, as YbCl3, were initially bound to each preparation by soaking for 12 h in pH 5.5 borate buffer to obtain Yb bound onto ligands having affinity constants for Yb equal to or greater than that for the weakly stable borate ligand, Yb > or = borate. The fraction of Yb > or = borate was measured and fragments then sequentially exposed to acetate, citrate, nitrotriacetate (NTA), and EDTA ions to allow exchange of Yb from Yb > or = borate with ligands having affinity constants for Yb equal to or greater than acetate (Yb > or = acetate), citrate (Yb > or = citrate), NTA (Yb > or = NTA), and EDTA (Yb > or = EDTA) ions. Binding of Yb > or = borate indicated the existence of two species of ligands: strong ligands binding essentially 100% of added Yb at levels of 1 to 1,300 ppm (0.1 N ADF) and at 1 to 7,000 ppm (ARNDF); and weaker ligands binding 4 and 8% of the Yb, respectively, at levels of added Yb greater than 1,300 ppm and 7,000 ppm. Ytterbium > or = acetate of ARNDF, but not 0.1 N ADF, was as resistant to exchange as Yb > or = citrate. Ytterbium > or = borate was exchanged extensively (85% or greater) with soluble ligands having affinity constants > or = NTA. Ytterbium resistance to proton displacement at pH of 1.5 increased with Yb > or = EDTA > Yb > or = NTA > Yb > or = citrate > Yb > or = acetate. Very efficient binding of Yb to CELL suggested that such chemical preparations are not representative of native cellulose. Hafnium (4+) was strongly bound to plant tissues rendering both Hf and Hf-bound DM insoluble at a pH of 1.5 and insoluble in a modified NDF solvent without EDTA. It is concluded that Yb specifically applied as Yb > or = acetate and Hf4+ are indelible markers for estimating sojourn time of undigested plant tissues at the normal pH of the rumen. Because of its resistance to proton displacement, Hf4+ would be an indelible marker for estimating sojourn time in more acidic postgastric segments of the gastrointestinal tract.     

重金属Pb~(2+)的抗原合成与鉴定

本研究旨在为重金属铅的ELISA检测方法建立提供一种免疫抗原并对其进行初步评估。试验采用络合剂CHX-A-DTPA双功能基团分别特异性结合重金属元素Pb2+和蛋白载体KLH,合成出复合络合物KLH-CHX-A-DTPA-Pb2+作免疫抗原,最佳合成条件pH值、反应时间、温度分别为9.0、(22±3)h和25℃;用BCA试剂盒、紫外扫描、三硝基苯磺酸法和原子吸收法对合成抗原做了初步评估,免疫抗原蛋白含量为2.66g/L,络合剂与Pb2+的偶联度为77.84%,结构与设计相似;5次免疫BALB/c小鼠后,抗血清可达128 000以上。结果提示,重金属Pb2+的抗原合成成功,免疫小鼠后特异性好,可用于重金属铅的ELISA检测方法研究。     

不同pH值和Fe^2＋胁迫对紫花苜蓿幼苗根系Fe^3＋还原力的影响

通过营养液培养的方法,研究了短时间不同pH值、铁浓度处理对紫花苜蓿（Medicagosativa）根系铁还原力的影响。结果表明：在酸胁迫下根系Fe^3＋还原力在短时间内显著提高,表明根系Fe^3＋还原力受到pH值影响,但随着处理时间的增加,影响逐渐减小;高铁诱导了根系铁还原力的提高;在短时间酸和铁共同胁迫下,紫花苜蓿根系Fe^3＋还原力随着溶液中铁浓度的增加而提高,并且pH4．5下的Fe^3＋还原力从处理开始就表现较高,表明酸性条件诱导铁还原力的提高;各处理间的还原力在处理开始时差异不明显,随着处理时间的增加,各处理间的还原力差异逐渐明显;总的来说,pH4．5下的铁还原力在处理初期比pH6．0下的还原力要高,然后随着处理时间的推移,pH4．5下的铁还原力有下降的趋势,而PH6．0下的铁还原力则有上升的趋势。     

载Zn~(2+)、Cr~(3+)离子的凹凸棒石黏土对鸡艾美耳球虫病的防治效果研究

研究载Zn~(2+)、Cr~(3+)离子的凹凸棒石黏土对鸡艾美耳球虫病的治疗和预防效果。通过离子交换的方法制备载Zn~(2+)、Cr~(3+)离子的凹凸棒石黏土。治疗试验:将雏鸡饲养至14日龄,随机分为5组,即空白对照组、感染不给药组、载Zn~(2+)、Cr~(3+)离子的凹凸棒石黏土治疗组、地克珠利治疗组、地克珠利和黏土联合治疗组,每组30只。感染后通过临床症状、粪便、体重、盲肠病变、卵囊值、抗球虫指数等评价载Zn~(2+)、Cr~(3+)离子的凹凸棒石黏土对鸡球虫病的治疗效果。预防试验:12日龄雏鸡随机分4组,空白对照组、3个预防组,每组各150只鸡。通过观察临床症状、血便堆数、卵囊数等综合评价载Zn~(2+)、Cr~(3+)离子的凹凸棒石黏土对自然发生的鸡球虫病的预防效果。治疗试验结果显示,地克珠利和黏土联合治疗组抗球虫指数达179.06,接近高效抗球虫药,载Zn~(2+)、Cr~(3+)离子的凹凸棒石黏土效果优于地克珠利。预防试验结果显示,在饲料中添加载Zn~(2+)、Cr~(3+)离子的凹凸棒石黏土可缩短球虫所致鸡血便持续时间,显著降低球虫感染造成的生长迟缓。上述结果表明,载Zn~(2+)、Cr~(3+)离子的凹凸棒石黏土对鸡球虫病具有较好的治疗效果和预防效果。     

脱二氧乙酰甲喹及N4-脱一氧乙酰甲喹的合成及结构表征

乙酰甲喹属于喹喔啉-N,N-二氧化物类兽药,有研究认定3-甲基-2-乙酰基-喹喔啉是乙酰甲喹的残留标示物。N4-脱一氧乙酰甲喹则被认为是乙酰甲喹在大鼠、鸡及猪肝微粒体中的主要代谢产物。为给乙酰甲喹代谢产物及代谢机制的深入研究提供理论依据,本研究采用Na2S2O4还原乙酰甲喹,合成3-甲基-2-乙酰基-喹喔啉和N4-脱一氧乙酰甲喹,经质谱、红外及1 H核磁等光谱技术对二者的化学结构进行了确证,为乙酰甲喹代谢产物及代谢机制的深入研究提供了理论依据。     

核壳结构型Fe_3O_4@C@mSiO_2复合物的制备

本文通过溶剂热法制备了粒径较均匀的磁性Fe_3O_4粒子,后利用喷雾干燥技术在其表面包覆了一层碳,采用溶胶—凝胶过程在碳层上包覆一层介孔结构的氧化硅,得到了磁性核/介孔壳结构的复合材料。氮气吸附脱附测试显示所得复合材料具有较高的孔容和比表面积。     

聚醚改性聚硅氧烷磷酸酯的合成和性能研究

以低含氢硅油、聚醚F-6为主要原料,利用硅氢加成反应制备聚醚改性聚硅氧烷(PES);之后分批加入P2O5,合成聚醚改性聚硅氧烷磷酸酯。对产物进行表征及性能测试,其具有良好的降低表面张力能力和较好的溶解性。     

Depletion of CD4(+) and CD8(high+) T-cells before the onset of viraemia during classical swine fever

Leukopenia, in particular lymphopenia, is a characteristic early event during classical swine fever (CSF). This was the case in both highly virulent (CSF virus (CSFV) strain Brescia) and moderately virulent (CSFV Uelzen) infections. The leukopenia involved leukocyte sub-populations in a disparate manner, with B-lymphocytes, helper T-cells and cytotoxic T-cells being the most affected. Depletion of lymphocyte sub-populations occurred 1-4 days before virus could be detected by RT-PCR in the serum. With the virulent Brescia virus, depletion was evident by 2 days post-infection (p.i.) but not until 3 days p.i. with an equivalent dose of the low virulent Uelzen strain. A lower (1000-fold) dose of the latter virus delayed these kinetics. gammadelta-TCR(+) T-cells were also reduced, but more so with the virulent Brescia infection. The final level of B-and alphabeta-T-cell lymphopenia was similar for all animals, including those infected with the lower virus dose. AnnexinV staining revealed that cell viability was clearly diminished, particularly interesting, considering the clinical differences between infections by Brescia and Uelzen viruses. It was the time p.i. and rate of appearance of dying cells which was more rapid in the virulent Brescia infections. Interestingly, the repeated blood sampling resulted in depletion of some leukocyte populations also in non-infected control animals. Particularly neutrophils and NK cells, and to a lower extent CD4(+), CD8(+) T-lymphocytes and B-lymphocytes were affected. Taken together, the data show that the alphabeta-T-lymphocyte subsets are particularly susceptible to modulation during the acute phase of CSF, being detectable before the onset of viraemia. The pathogenic mechanism therein would involve indirect virus-host interactions, probably originating from the site of primary infection, rather than a direct effect of the virus or viral protein. Furthermore, these characteristics offer an explanation for the retardation of the cellular and humoral immune response observed during classical swine fever.     

咪达唑仑对山羊不同脑区Ca~(2+)-Mg~(2+)-ATP酶活性的影响

为研究咪达唑仑对山羊不同脑区Ca~(2+)-Mg~(2+)-ATP酶活性的影响,探讨其在中枢麻醉的作用机制。试验用15只健康山羊,3只为生理盐水对照组,其余为试验组,试验组山羊肌肉注射14 mg/kg体重咪达唑仑。分别在给药后诱导期、麻醉期、恢复Ⅰ期和恢复Ⅱ期4个时间点,每点剖杀3只山羊取脑组织,采用分光光度法测定不同脑区Ca~(2+)-Mg~(2+)-ATP酶活性。结果注射咪达唑仑能明显抑制山羊大脑、丘脑、小脑和脑干的Ca~(2+)-Mg~(2+)-ATP酶活性,这种变化趋势与山羊肌肉注射咪达唑仑麻醉后行为学变化基本一致,海马的Ca~(2+)-Mg~(2+)-ATP酶活性在整个麻醉过程中无明显变化。表明咪达唑仑的麻醉作用可能与抑制山羊大脑、丘脑、小脑和脑干的Ca~(2+)-Mg~(2+)-ATP酶活性相关。