Achievement of pencil-beam radiation from a TM01 modecircular waveguide source

A method employing appropriately placed parallel-metallic plates in the aperture of a TM₀₁ mode circular waveguide source so as to have it produce pencil-beam radiation is described and analyzed. Programmed computations, with experimental verification, are given for the case of a C-Band TM₀₁ source flared out to a conical horn so as to produce moderate (22 dBi) gain. Means of extending the method to achieve higher gains (40 dBi to 60 dBi) and to modify the plate arrangement so as to produce the same effect with a TE₀₁ mode are briefly outlined     

Induction of hapten-specific tolerance by interleukin 10 in vivo

Interleukin 10 (IL-10) is released during the induction phase of contact sensitivity and was shown in prior functional studies to convert epidermal Langerhans cells (LC) from potent inducers of primary immune responses to specifically tolerizing cells in vitro. To investigate whether IL-10 also subserves the function of a tolerizing agent in vivo ears of BALB/c or C3H mice were injected intradermally with 1-2 micrograms of recombinant mouse (rm)IL-10 8 h before epicutaneous application of 3% trinitrochlorobenzene (TNCB; a contact allergen). As a control, mice were injected with phosphate-buffered saline or IL-10 plus neutralizing amounts of anti-IL-10 mAb. 5 d later, mice were challenged with 1% TNCB on contralateral ears and ear swelling response was measured 24 h later. Whereas control-treated mice showed a normal ear swelling response to epicutaneous challenge (delta mm-2 = 25 +/- 5), ear swelling response of IL-10-treated animals was significantly inhibited (delta mm-2 = 3 +/- 2). Coinjection of IL-10-specific mAb together with rmIL-10 completely abrogated this effect. To differentiate between a state of nonresponsiveness and induction of tolerance by IL-10, mice initially treated with IL-10 and TNCB were resensitized with 3% TNCB in the absence of any treatment after 14 d of rest (group 1). Again mice were challenged 5 d later and ear swelling responses were tested. Whereas control mice treated with allergen alone (group 2) showed a good swelling response (delta mm-2 = 28 +/- 6), IL-10-treated mice (group 1) showed a minimal response towards application of allergen (delta mm-2 = 4 +/- 2). To show that anergy induction by IL-10 was antigen-specific, mice initially treated with IL-10 plus TNCB were exposed to 0.5% dinitrofluorobenzene (DNFB) 14 d later (group 1). After challenge with 0.1% DNFB, IL-10-treated mice showed an ear swelling response (delta mm-2 = 13 +/- 3; group 1) similar to that of control mice only sensitized with DNFB (delta mm-2 = 14 +/- 3; group 3). In an attempt to show the induction of antigen-specific tolerance in these mice in vitro, regional lymph nodes of mice initially treated with TNCB plus IL-10 (group 1) and control-treated mice (groups 2 and 3) were prepared and cultured in the presence of TNBS, dinitrobenzene sulfonate (DNBS), or medium to measure antigen-specific proliferation.(ABSTRACT TRUNCATED AT 400 WORDS)     

Adsorption mode of ethyl pyruvate on platinum: an in situ XANES study

The adsorption of ethyl pyruvate on Pt(111) has been studied by in situ XANES measurements in the presence and absence of hydrogen. Depending on the hydrogen and ethyl pyruvate pressure, the C and O K‐edge spectra exhibit distinctly different angular dependence. Without hydrogen ethyl pyruvate is oriented preferentially perpendicular to the surface, indicating bonding via the O lone pairs. In the presence of hydrogen the mean orientation is more tilted towards the surface. Likely, ethyl pyruvate also interacts with Pt via its π system under these conditions. The observed angle‐dependent shift of the energy of the π* and σ* resonances indicates the coexistence of differently adsorbed ethyl pyruvate species. The experimental findings demonstrate the importance of the in situ approach for unraveling the adsorption mode of ethyl pyruvate in the enantioselective hydrogenation over cinchona‐alkaloid‐modified Pt. This revised version was published online in July 2006 with corrections to the Cover Date.     

Important Parameters for the Manufacture of Slow-Release Matrix Pellets With an Aqueous Dispersion of Quaternary Poly(meth)acrylates in the Rotary Fluidized Bed

ABSTRACT

The manufacture of slow-release matrix pellets with an aqueous dispersion of quaternary poly(meth)acrylates was investigated in the rotary fluidized bed. By considering the moisture content of the fluidized bed to be the key process parameter, it was measured on-line throughout the whole manufacturing process. A specially designed sampling device opened new ways to apply NIR spectrometry in laboratory scale processes. It was shown that reproducibly improved pellet properties can be achieved by reproducing the moisture content of the (rotary) fluidized bed. Moisture plateaus proved to be a suitable way to optimize the sphericity of the pellets. Premoisturizing was found to be a very effective tool to achieve slow-release dissolution of the model drug theophylline.     

Front-to-back ratio of a smooth metallic-wall conical horn

By expressing the front fields of the subject conical horn in terms of its gain, and by explicit evaluation of the known GTD expressions for its back field, a concise formula for its front-to-back (F/B) ratio is obtained. The much lower level of back field produced by a corrugated-wall horn as compared to a smooth metallic-wall horn of the same gain is then pointed out.     

Spc98p and Spc97p of the yeast gamma-tubulin complex mediate binding to the spindle pole body via their interaction with Spc110p

Previously, we have shown that the yeast gamma-tubulin, Tub4p, forms a 6S complex with the spindle pole body components Spc98p and Spc97p. In this paper we report the purification of the Tub4p complex. It contained one molecule of Spc98p and Spc97p, and two or more molecules of Tub4p, but no other protein. We addressed how the Tub4p complex binds to the yeast microtubule organizing center, the spindle pole body (SPB). Genetic and biochemical data indicate that Spc98p and Spc97p of the Tub4p complex bind to the N-terminal domain of the SPB component Spc110p. Finally, we isolated a complex containing Spc110p, Spc42p, calmodulin and a 35 kDa protein, suggesting that these four proteins interact in the SPB. We discuss in a model, how the N-terminus of Spc110p anchors the Tub4p complex to the SPB and how Spc110p itself is embedded in the SPB.     

Preparing of pellets by extrusion/spheronization using different types of equipment and process conditions

Introduction: The focus of this work was to produce matrix pellets made by extrusion/ spheronization using two types of equipment. The aim was to accomplish the laboratory-scale I process that has been already optimized and accepted with another type of equipment (laboratory-scale II).

Methods: A matrix pellet formulation consisting of MCC, Eudragit NE 30D and diclofenac sodium was used in the two types of equipment. Physico-chemical parameters and the dissolution profiles of the pellets in phosphate buffer pH 6.8 were compared.

Results: Pellets from both processes were similar in shape and tensile strength. They differed in particle size and dissolution profile. This may be contributed to different spheronization conditions.     

Computations of the aperture admittance of an axial slot on a dielectric coated cylinder

An extensive set of curves for the aperture admittance of a waveguide-fed axial slot on a coated metal cylinder is presented for both an underdense plasma and a Teflon coating. Examination of these curves shows that a slot on a cylinder with aKaof 2 to 3 has about the same aperture admittance as the identical slot opening onto a flat ground plane.