Studium der alkalischen hydrolyse der ester-bindungen in einem acrylsäureethylester-acrylnitril-divinylbenzol-perlcopolymeren

In consideration of results of a preceding paper the mathematical evaluation of conversion curves obtained by alkaline hydrolysis of ester bonds of ethyl acrylateacrylonitrile-divinylbenzene bead copolymers was carried out. The influence of individual factors (reaction temperature, molecular ratio between the hydrolytic agent and the macromolecular substance, the size of copolymer particles, and the density of its network) was determined by means of reaction constants and diffusion coefficients.     

Overview of a quality assurance/quality control compliance program consistent with FDA regulations and policies for somatic cell and gene therapies: a four year experience

Somatic cell and gene therapy involve the application of biological technologies to an individual patient through the use of living cells which provide a therapeutic benefit (Aliski, 1991). Various forms of cellular and gene therapies are being developed and evaluated in an increasing number of clinical trials for congenital and acquired disorders. The potential and progress of these therapeutic applications have resulted in an increasing effort by the Food and Drug Administration (FDA) to develop the regulatory framework under which these therapeutic approaches would insure safety and efficacy, the primary mandate of the FDA. Over five years ago Cellcor began to define the parameters, specifications, and conditions relevant to a Quality Assurance/Quality Control (QA/QC) program that has evolved to insure safety and maximize the efficacy of applications of the company's ex vivo technology, autolymphocyte therapy. Autolymphocyte therapy is an outpatient form of somatic cell immunotherapy based upon the infusion of T cells that have been activated ex vivo using a combination of previously generated autologous cytokines and an anti-CD3 monoclonal antibody. We have been able to demonstrate the feasibility for the safe, controlled, and consistent preparation and delivery of a cellular therapy by application of relevant GMP regulations. This presentation reviews aspects of this program and chronicles our experience which at present amounts to over 4400 in fusions for over 700 patients. This program provides a high degree of assurance that a cellular therapy program can be carried out in a multisite mode involving hundreds of patients through the strict adherence to cGMP as set forth in existing regulations.(ABSTRACT TRUNCATED AT 250 WORDS)     

高氯酸杂环配合物金属盐的激光起爆（英）

1 IntroductionNowadays the electrical way of blast-caps initiation istraditional. But the devices used for this process are in-herently susceptible to an accident initiation by externalstimuli such as an electrostatic discharge (ESD), elec-tromagnetic interference (EMI), and radio wave irradia-tion (RI). Pulse laser initiation of explosives is a newperspective method. Pulse lasers provide practical meansof electrical isolation of the energetic materials, therebyeliminating hazards associat…     

Einflu? des Pectins auf die elektrokinetischen Eigenschaften von Pulpesuspensionen aus ?pfeln

Apple pulp suspensions to which different kinds of pectin in concentration up to 500 g.m^–3 was added were studied electrophoretically. It was shown that the natural pectin exerts an essential influence upon the adsorption ability of the pectin added, and upon the electrokinetic potential of the tissue particles respectively.

     

Landsat digital enhancements for change detection in urban environments

Comparison of Landsat digital classifications from two dates has met with limited success for change detection in urban environments. The capabilities of digital enhancements for displaying change were therefore investigated as an alternative procedure for this task. Three different color enhancements, an overlay of band 5, ratios of bands 5 and 7, and a vegetation index, were generated using 1974 and 1978 Landsat data of Hamilton, Ontario. The ratios only emphasize major changes. The band 5 overlay shows change most clearly, but the vegetation index enhancement is almost as good and in addition to showing change also emphasizes the urban boundary and the major road network. It is suggested that change enhancements could be used effectively by agencies responsible for monitoring urban development over large areas.     

Determination of fexofenadine in tablets by capillary electrophoresis in free solution and in solution with cyclodextrins as analyte carriers

Capillary electrophoresis (CE) methods for the determination of fexofenadine (FEX) in commercial pharmaceuticals were developed. It was demonstrated that FEX could be effectively analyzed in free solution cationic CE at low pH. Another analytical approach studied was based on cyclodextrin (CD) modified CE where highly charged CD derivatives served as analyte carriers. In this way, the separation range was spread to physiological pH region and a CE analysis of FEX, present actually in its zwitterionic form, could be accomplished. Several parameters affecting the separations were studied, including the type and concentration of carrier ion, counterion, analyte carrier, and pH of the buffer. The methods based on the free solution CE and CD-modified CE were compared each other, validated, and applied for the determination of FEX in tablets.     

Nacre in Mollusk Shells as a Multilayered Structure with Strain Gradient

How do living organisms attain the complicated shapes of grown bio‐composites? This question is answered when studying the mechanics of the nacre layer in the bivalve mollusk shells. In this study, the internal strains/stresses across the shell thickness are profiled as a function of depth by strain gauge measurements during controlled etching in the selected areas. Measurements of stress release under etching provide clear evidence that the investigated shells, in fact, are strained multilayered structures, which are elastically bent due to the forces evolving at the organic/inorganic interfaces. The stresses are mostly concentrated in the “fresh” nacre sub‐layers near the inner surface of the shell adjacent to the mollusk mantle. This analysis unexpectedly shows that the elastic bending of the nacre layer is due to strain gradients which are originated in the gradual in‐depth changes of the thickness of ceramic lamellae. The changes mentioned were directly observed by scanning electron microscopy. By this sophisticated design of the ultra‐structure of the nacre layer, the bowed shape of the bivalve shells is apparently achieved.     

Ionomeric polyurethanes of pyridinium type with side azobenzene groups

New polyurethane cationomers synthesized by a two‐step substitution postreaction of urethane hydrogen atoms with nitroazobenzene groups were studied. As a starting polymer, a polyurethane based on poly(tetramethylene oxide)diol, isophorone diisocyanate, and 2,6‐bis(hydroximethyl)pyridine was used. After a preliminary metalation of the above polymer with natrium hydride, by reaction of polyurethane N‐sodate with 4‐nitro‐4′(β–iodoethylurethane)azobenzene, chromophoric groups between 2.85 and 10.53 wt % could be incorporated instead of hydrogen. Such polymers partially functionalized with azobenzene and further quaternized with methyl iodide led to the formation of pyridinium polyurethane cationomers N‐modified with nitroazo groups. The photosensible properties of the azobenzene chromophore in a polymer solution and film state indicated important differences in their photoresponse. In the polymer solution, the trans–cis photoisomerization of the chromophore is accompanied by an irreversible photobleaching effect, while under the same UV irradiation conditions, the ionomeric films exhibited an enhanced photostability. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1240–1247, 2002     

Subcritical Crack Growth in Lead Zirconate Titanate

Subcritical crack growth in terms of velocity–stress intensity factor ( v – K ) curves in lead zirconate titanate (PZT) were experimentally characterized on poled and unpoled compact tension specimens. The poled specimens were tested under open- and short-circuit electrical boundary conditions, which resulted in an increase in fracture toughness by 0.2 MPa·m^1/2 for the accessible velocity range ( v = 10⁻⁹ to 10⁻⁴ m/s) in the open-circuit case. Subcritical crack growth of unpoled specimens was obtained under ambient (relative humidity = 35%) and dry (relative humidity ∼ 0.02%) conditions over a regime in stress intensity factor of 0.5 MPa·m^1/2.