Surface tailoring of poly(ethylene terephthalate) via ligand-tethered comb-like PEG to enhance endothelialization

The comb-like PEG (CPEG) end-tethered with l-lysine was explored to surface modification of PET to enhance endothelialization. The hydroxyl end groups of CPEG were oxygenated into aldehyde groups. The CPEG-CHO was grafted onto the aminolysized PET. The l-lysine was then end-tethered onto surface via the residual aldehyde groups. The surface modification was confirmed by ATR-FTIR, contact angle and XPS measurements. The endothelial cell adhesion, proliferation and viability results indicated that the PET-CPEG resisted cell adhesion and growth, where as PET-CPEG-lysine promoted cell adhesion and growth. The MTT assay and total cell protein tests indicated that the endothelial cells on PET-CPEG-lysine had high viability. Cell spread uniformly and covered completely on the PET-CPEG-lysine. The CPEG end tethered with l-lysine could regulate cell adhesion and growth and enhance surface endotheliazation.     

Fabrication and application of single nucleotide polymorphisms library on magnetic nanoparticles using adaptor PCR

We have developed a novel approach to fabricate single nucleotide polymorphisms (SNPs) library on magnetic nanoparticles (MNPs) based on adaptor PCR. Each SNP locus in the library was interrogated by hybridization with a pair of allele specific dual-color fluorescence (Cy3, Cy5) probes to determine SNP. Two SNPs loci (M235T and A-6G) associated with essential hypertension in the angiotensinogen (AGT) gene were detected by this method and their fluorescent signals were quantified. The fluorescent ratios (match probe: mismatch probe signal) of homozygous genotypes were over 3.0, whereas heterozygous genotypes had ratios near to 1.0. Without any complex multiplex PCR procedure, it is a simple, efficient and reliable method for the multiplex SNPs detection using limited amount of DNA samples from individuals.     

Selective dissolution of eodiagenesis cements and its impact on the quality evolution of reservoirs in the Xing’anling Group, Suderte Oil Field, Hailar Basin, China

Reservoirs in the Xing’anling Group in the Suderte Oil Field, Hailar Basin exhibit ultra-low to low permeability and high tuffaceous material content. This study comprehensively analyzed diagenesis and quality evolution of these low-permeability reservoirs using thin sections, SEM samples, rock physical properties, pore water data, as well as geochemical numerical simulations. Calcite and analcite are the two main types of cements precipitated in the eodiagenetic stage at shallow burial depths in the reservoirs. These two cements occupied significant primary intergranular pores and effectively retarded deep burial compaction. Petrography textures suggest selective dissolution of massive analcite and little dissolution of calcite in the mesodiagenetic stage. Chemical calculations utilizing the Geochemist’s Workbench 9.0 indicated that the equilibrium constant of the calcite leaching reaction is significantly smaller than that of the analcite leaching reaction, resulting in extensive dissolution of analcite rather than calcite in the geochemical system with both minerals present. Numerical simulations with constraints of kinetics and pore water chemistry demonstrated that the pore water in the Xing’anling group is saturated with respect to calcite, but undersaturated with analcite, leading to dissolution of large amounts of analcite and no dissolution of calcite. Significant secondary intergranular pores have formed in analcite-cemented reservoirs from selective dissolution of analcite in the mesodiagenetic stage; the analcite dissolution formed preferential flow paths in the reservoirs, which promoted feldspar dissolution; and dissolution of such minerals led to the present reservoirs with medium porosity and low permeability. Calcite-cemented tight reservoirs have not experienced extensive dissolution of cements, so they exhibit ultra-low porosity and permeability.     

Distinguishing between cis/trans isomers of monounsaturated fatty acids by FAB MS

Fast-atom bombardment (FAB) mass spectrometry in the negative ion mode can be used to unambiguously distinguish between cis and trans isomers of monounsaturated fatty acids by the relative signal strengths of an intense pair of ion signals. Under normal FAB ionization/desorption conditions, the deprotonated molecules (i.e., [M - H]-) of six fatty acids underwent charge remote fragmentation. A characteristic fragmentation pattern of two intense peak clusters of peaks with three weak intervening clusters of peaks are used in each case to identify the position of the double bond. The possibility of resonance electron capture occurring during the FAB process is discussed.     

Removal of ammonium from wastewater using calcium form clinoptilolite

The paper concerns the removal of ammonium ions from aqueous solution using a modified clinoptilolite-Ca(2+)-formed clinoptilolite (CaY) prepared from natural clinoptilolite. The batch study results show that the pH has an effect on ammonium adsorption capacity as it can influence both the character of the exchanging ions and the clinoptilolite itself; the CaY has a high selectivity to NH(4)(+) and the exchange decreases with increasing temperature; ammonium ion uptake onto CaY was suitably described by the Langmuir model. The column results indicated that the effluent of simulated wastewater treated with CaY could meet the integrated wastewater discharge standard of China, and CaY can be circulated through regenerating by Ca(OH)(2).     

Anchored oxygen-donor coordination to iron for photodegradation of organic pollutants

A photocatalyst of oxygen-donor coordination to iron, complex of 5-sulfosalicylic acid (SSA) with ferric ion, supported on resin to cycle Fe3+/Fe2+ center under visible irradiation can effectively generate *OH radicals from H2O2, leading to degradation of organic pollutants in water. The higher turnover number was achieved by this catalyst for the degradation of model compound than those reported for the general N-donor ligands catalysts. The reversible "on/ off" switching of Fe3+/Fe2+ complexation with SSA, coupled with the phenol/phenoxyl radical conversion of the o-phenoxyl moiety of SSA, produces an ideal catalytic system that separates the Fenton reaction and the followed oxidations by *OH radicals (in water phase) from the regeneration of the catalytic species, Fe (SSA)2-, which occurs on the surface of resin. This system not only inhibits the undesired destruction of the ligands by *OH radicals, improving the stability of the catalyst, but also avoids the unnecessary decomposition of H2O2 into HO2* that occurs in the homogeneous Fenton system. Therefore, the system suggests an efficient utilization of H2O2 for degradation of organic pollutants.     

Influence of atmospheric turbulence on the spatial correlation properties of partially coherent flat-topped beams

The analytical expression for the spectral degree of coherence of partially coherent flat-topped beams propagating through the turbulent atmosphere is derived, and the spatial correlation properties are studied in detail. In particular, we find that the oscillatory behavior and phase singularities of the spectral degree of coherence may appear when partially coherent flat-topped beams propagate through the turbulent atmosphere; this behavior is very different from the behavior of Gaussian Schell-model beams. But the oscillatory behavior becomes weaker with increasing turbulence and even disappears when the turbulence is strong enough. The width of the spectral degree of coherence is always smaller than that of the spectral density in the far field when the turbulence is strong enough, whereas the width of the spectral degree of coherence in free space can be either larger or smaller than that of the spectral density in the far field.     

Facile fabrication of magnetic nanocomposites of ordered mesoporous carbon decorated with nNickel nanoparticles

A magnetic nanocomposite of ordered mesoporous carbon (CMK-3) decorated with nickel nanoparticles was synthesized successfully by a simple chemistry method. Nickel nanoparticles were prepared and uniformly supported on ordered mesoporous carbon CMK-3 by reduction route with CMK-3 as a reducing agent at 673 K. The Ni/CMK-3 composite materials were characterized by powder X-ray diffraction, nitrogen sorption, and transmission electron microscopy. As-prepared nickel nanoparticles supported on CMK-3 were crystalline with a face-center-cubic phase and a size distribution ranging from 10 to 60 nm. The BET special surface area and pore volume of Ni/CMK-3 were as high as 797 m2 g(-1) and 0.72 cm3 g(-1), respectively. The formation mechanism of the nickel nanoparticles outside the surface of CMK-3 was preliminarily discussed. The hysteresis loops of the CMK-3 decorated with nickel nanoparticles were measured by vibrating sample magnetometer (VSM), and the results showed that the composite was ferromagnetism with the saturated magnetization of 15 emu/g, and the coercivity value of 214 Oe. Furthermore, the application of Ni/CMK-3 as magnetically separable adsorbent for vitamin B2 was primarily examined in this study.     

钨酸铅晶体生长及其组份挥发

本文首次报道了用坩埚下降技术生长钨酸铅（PWO）晶体;研究了提拉和坩埚下降两种技术生长PWO晶体的组份挥发,得到的结果是PbO的挥发速率高于WO₃,并对一组晶体不同部位的X射线发光性能作了研究．     

退火处理对PbWO4晶体闪烁性能的影响

本文报道了用改进的坩埚下降技术生长ＰｂＷＯ４晶体经退火处理后,对Ｘ射线激发发射谱,透过谱以及抗辐照损伤能力的影响,指出ＰｂＷＯ４晶体在适合的富氧气氛环境和温度制度下经退火处理后,闪烁性能及抗辐照能力明显得到改善。