Thermostability of landscape phage probes

Immunoassays have traditionally relied on antibodies as diagnostic probes. Their use outside of a laboratory, however, may be problematic because antibodies are often unstable in severe environmental conditions. Environmental monitoring requires thermostable probes, such as landscape phage, that carry thousands of foreign peptides on their surfaces, are superior to antibodies, and can operate in non-controlled conditions. While parent wild-type phage are known to be extremely stable in various media at high temperatures, no work has been done to demonstrate the stability of landscape phage probes. We examined the thermostability of a landscape phage probe and a monoclonal antibody specific for -galactosidase in parallel in an enzyme-linked immunosorbent assay (ELISA) format. They were both stable for greater than six months at room temperature, but at higher temperatures the antibody degraded more rapidly than the phage probe. Phage retained detectable binding ability for more than six weeks at 63 °C, and three days at 76 °C. The activation energy of phage degradation was determined to be 1.34×10⁵ J/mol. These results confirm that phage probes are highly thermostable and can function even after exposure to high temperatures during shipping, storage and operation.     

The volume and compressibility change for the formation of transition metal sulfate ion pairs at 25°C

The apparent molal volume and adiabatic compressibilities of some transition metal (Mn²⁺, Co²⁺ Ni²⁺, Cu²⁺, Zn²⁺, and Cd²⁺) sulfates have been determined at 25°C. Values of to 11.4 cm³-mole^–1 and to 31.3 × 10^–4cm³-mole^–1-bar^–1 at 1 atm were found for the formation of the transition metal sulfate ion pairs. These results are in good agreement with the values obtained from the high-pressure conductance measurements of Fisher et al., Shimizu et al., and Taniguchi et al. The volume and compressibility data indicate that 3.1±0.7 water molecules are lost when transition metals form ion pairs with SO ₄ ^2– . The fractions of inner-sphere ion pairs (20%) estimated in this study are in good agreement with the values obtained from ultrasonic measurements.     

High temperature corrosion behaviour of M(Co,Ni)CrAIY-coatings on high temperature materials-microanalytical investigations

In our former investigations, the phenomenon high temperature corrosion (HTC) was described exemplarily on selected materialcoating combinations for blades of stationary gas turbines, mainly in the temperature region of up to 750° C. To answer the question, in which manner higher gas inlet and/or higher material surface temperature would influence the HTC behaviour, a special analytical technique—the integral layer profile analysis—was introduced to ameliorate concentration profile methods. By examining IN 738 LC specimens with CoCrAlY plasma spray coating, stressed by hot gas at 900° C, the limits of this system are shown by explaining the corrosion mechanism; the method is also used for other systems, e.g. U 520 with NiCrAlY coating at 750° C.     

Phytoecdysteroids of Plants of the Silene Genus. 2-Deoxyecdysterone-25-Acetate from Silene wallichiana

The new ecdysteroid 2-deoxyecdysterone-25-acetate was isolated from roots of Silene wallichiana Klotzsch.     

Localization of Iα and Iβ phases in algal cellulose revealed by acid treatments

Highly crystalline I-rich type Cladophora cellulose, which had been kept in never-dried condition, was treated in 60wt% sulfuric acid at 100°C, for 1–48h. The cellulose microcrystals thus obtained were analysed by X-ray diffractometry, FT-IR, and transmission electron microscopy. The I component was found to be more degraded than the I component. The cellulose I/I ratios of the samples acid-treated for 0, 24, and 48 h were about 8:2, 6:4, and 4:6, respectively. After the acid treatment, the microcrystals became narrower in width, and very sharp at their ends. These results indicate that the I phase is mostly located at the surface of the microcrystals, which is morphologically more susceptible to the acid treatment.     

Analysis of nitro-PAHs in diesel exhaust particulate extracts with multicolumn HPLC

Summary A method is described for the determination of nitrated polynuclear aromatic hydrocarbons (nitro-PAHs), in particular 1-nitropyrene, in diesel particulate extracts. The method employs a multidimensional HPLC (column switching) technique with final on-line peak identification by UV-VIS spectral comparison with standards. To achieve exceptional chromatographic selectivity for nitro-PAHs, a new pyrene butyric acid amide phase has been prepared which is capable of forming donor-acceptor complexes with them. With this technique it is possible to confirm the presence of 1-nitropyrene in the range 3–100 ng/mg on filter-collected diesel soot. Its utility was demonstrated with diesel exhaust extracts spiked with varying levels of 1-nitropyrene and proved to be highly selective.Parts of this work have been presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984.Dedicated to Prof. J. F. K. Huber at the occasion of his 60th birthday.     

A multireference configuration interaction method based on the separated electron pair wave functions

A multireference configurational interaction method based on the separated electron pair (SEP) wave functions, SEP‐CI approach, has been developed as an approximation to the traditional CASSCF method. It differs from the CASSCF method in that active orbitals are obtained from the SEP wave function without further optimization in the subsequent CI calculations, and the active space is automatically constructed according to the occupation coefficients of SEP natural orbitals. These features make the present SEP‐CI method computationally much less demanding than the CASSCF method. The applicability of the SEP‐CI method is illustrated with sample calculations on the insertion reaction of BeH₂ and dissociation energies of LiH, BH, FH, H₂O, and N₂. © 2005 Wiley Periodicals, Inc. J Comput Chem 27: 39–47, 2006     

四甲基对联苯二胺光敏化聚苯乙烯砜及其模型化合物二苄基砜分解机理的研究

N、N、 N’、N’-四平基对联苯二胺(NTMB)和 3、3’、5、5’-四甲基对联苯二胺(TMB)可以有效地光敏化二苄基砜(DBS)分解和聚苯乙烯砜(PSS)降解。敏化作用是按电子转移机理进行的,电子转移过程可以由NTMB的单重激发态,也可以由三重激发态发生。由三重态电子转移产生的三重态离子自由基对进一步反应生成产物的效率比单重态离子自由基对的效率高10倍。     

Superoxes,high temperature universal phases in (GC)2

Most of the common classes of organic compounds chromatograph normally on Superoxes. There is no tailing or adverse effect from excessively different activity different activity coefficients. Superoxes are therefore universal phases for gas chromatography. This is also expressed by a wide useful temperature range from ～50° to ～300°. High MW Superox-4 has a MAOT about 20° higher than the lower MW Superox-0.1. Several applications illustrating the versatility of Superox phases in (GC)² are presented.     

The preparation of thick-film glass capillary columns

A detailed method for the routine preparation of glass capillary columns is presented. The method consists of coating a glass tube with quartz powder prior to pulling the tube into a capillary. The inner surface of the capillary consists of an even distribution of quartz particles fused to the walls. This surface has been found readily deactivated by standard procedures and ideal for the preparation of thick-film glass capillary columns. The method has been thoroughly tested in two independent laboratories to ensure that the procedures described are reproducible.