SYNTHESIS OF MESOPOROUS POLY(STYRENE-co-MALEIC ANHYDRIDE)/SILICA HYBRID MATERIALS VIA A NONSURFACTANT-TEMPLATED SOL-GEL PROCESS*

Mesoporous poly (styrene-co-maleic anhydride)/silica hybrid materials have been prepared. The synthesis wasachieved by the HCl-catalyzed sol-gel reactions of tetraethyl orthosilicate (TEOS) and styrene-maleic anhydride copolymerin the presence of 3-aminopropyl triethoxysilane (APTES) as a coupling agent and citric acid as a nonsurfactant template orpore-forming agent, followed by ethanol extraction. Characterization results from nitrogen sorption isotherms and powder X-ray diffraction indicate that polymer-modified mesoporous materials with large specific surface areas (e.g. 900 m~2/g) andpore volumes (e.g. 0.6 cm~3/g) could be prepared. As the citric acid concentration is increased, the specific surface areas, porevolumes and pore diameters of the hybrid materials increase.     

Impact of prefractionation using Gradiflow on two-dimensional gel electrophoresis and protein identification by matrix assisted laser desorption/ionization-time of flight-mass spectrometry

Prefractionation of protein samples prior to two-dimensional electrophoresis (2-DE) has the potential to increase the dynamic detection range for proteomic analysis. We evaluated a membrane-based electrophoretic separation technique (Gradiflow) for its ability to fractionate an exoproteome sample from the filamentous fungus Trichoderma reesei. The sample was separated on the basis of size and charge. Buffer optimization was found to be necessary for successful size fractionation. Fractionation by charge was used to resolve the sample into four fractions that were subjected to analysis by two-dimensional electrophoresis (2-DE). Enhanced detection of low-abundance proteins with selective removal of high-abundance species was achieved. Fractionated and unfractionated samples were examined for differences in the ability to identify proteins following 2-DE using trypsin in-gel digestion followed by peptide mass fingerprinting using matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). Fractionated samples showed marked improvement in protein identification ability and sequence coverage. This study demonstrates the utility of the Gradiflow for fractionation, resulting in an enhancement of resolution and characterization of a moderately complex proteome.     

含钼化合物及其配合物的抗癌抗肿瘤活性

钼是生命体所必需的微量元素。本文介绍了钼在人体中的作用，钼缺乏和钼过量对人体的影响，并介绍了含钼化合物以及配合物的抗癌抗肿瘤研究情况。     

The Greatest Lower Bound of a Boros–Moll Sequence

Mathematical Notes - The Boros–Moll polynomials $$P_m(a)$$ arise in the evaluation of a quartic integral. In the past few years, there has been some remarkable research on the properties of...     

弱酸性介质中Silicalite—1分子筛膜的制备与表征

在ＳｉＯ２－ＴＰＡＢｒ－ＮＨ４Ｆ－Ｈ２Ｏ弱酸性氟离子体系中,在玻璃基片上采用水热晶化法制备了Ｓｉｌｉｃａｌｉｔｅ－１（全硅ＺＳＭ－５）分子筛膜．通过ＸＲＤ,ＳＥＭ分析测试手段对所合成的分子筛膜进行了表征,并对膜合成中硅源,水量等影响因素进行了考察．     

镰游仆虫Euplotes harpa无性分裂时期形态发生的研究

在显微和亚显微水平上,研究了镰游仆虫Ｅ．ｈａｒｐａ的形态结构及其在无性分裂时期的形态发生。对无性分裂期间各种纤毛器原基的起源和发育作了详细的观察和描述,着重注意了各种纤毛器原基的相互关系和发生的顺序性。同时,对基体在皮层上的“移动”及基体与“基体托架”的关系也作了研究和分析。     

负载型贵金属催化剂的硫中毒机理——载体的酸碱性与催化剂抗硫性能的关系

以H_2S为毒物,H_2-O_2反应为催化模型反应,制备并考察了一系列不同酸碱性的负载型钯催化剂。以NH_3和吡啶为探针分子,用程序升温脱附(TPD)或红外光谱法测定了催化剂的酸碱性。用交替脉冲微反色谱技术评价了催化剂的活性和耐硫中毒性,并对催化剂的耐硫性能和载体酸碱性进行关联和解释。在以上研究基础上,指出了提高催化剂抗硫性能的途径。