Cylindrical Cassette Research Articles

Automatic Weissenberg data collection system for time-resolved protein crystallography

A totally new type of fully automatic Weissenberg data-collection system called “Galaxy” was developed and was installed at the Photon Factory. This automatic data collection system consists of a rotated-inclined focusing monochromator, a screenless Weissenberg type camera, an image reader, an eraser, a cassette transportation mechanism, a control console and a safety and high-speed computer network system linking a control console, data processing computers and data servers. The special characteristics of this system are a Weissenberg camera with a fully cylindrical cassette which can be rotated to exchange a frame, a maximum number of 36 images to be recorded in an IP cassette, and a very high speed IP reader with five reading heads. Since the frame exchange time is only a few seconds, this system is applicable for time-resolved protein crystallography at seconds or minutes of time-scale.

New Miniaturized Highly Sensitive Immunoassay Device for Quantitative Measurement of Soluble or Particular Antigen or Antibodies in a Liquid Sample

Modern clinical practice requires small, easy-to-use, quantitative, automated near-the-patient test systems. Any new test system must match the clinical needs for faster and cost-effective technological approaches. The TECHNODISK concept addresses many of the key features required for rapid immunoanalysis, i.e., microfluidics, speed, safety, flexibility, and capability for multitest panels. The system is a flat cylinder cassette named TECHNODISK composed of two plastic parts. The bottom part is a polystyrene plastic mould designed with three concentric areas separated by walls in which holes have been made that allow for the circulation of fluids from the inner area, to the middle chamber, and finally to the outer waste area. Fluid is moved between the different areas by rotation on a central drive that produces sufficient centrifugal force to allow the fluid transfers. The lid is a flexible plastic mould that closes tightly over the bottom part, forming a flat cylindrical cassette that can be turned from the bottom by the action of a peripheral drive. Two holes are punched through the plastic to allow addition of the sample and wash reagent into the middle chamber (sample hole) and the addition of fluid into the inner area of the chamber to pick up the coated microbead conjugate (inner hole). The bottom part can be moved relative to the lid to two fixed positions (clockwise and counterclockwise) that open and close valves in the cassette. In one position, holes between the inner area and middle chamber are …

Crystal structure of a quaternary Nd–Ni–Si–B compound-refinement of synchrotron radiation data

High-resolution synchrotron-radiation powder data have been obtained for a new quaternary Nd–Ni–B–Si compound with the nominal composition of NdNi 8SiB 3. The data were collected on a (573 mm radius) cylindrical cassette diffractometer using imaging plates. The crystal structure of the new compound has been determined and refined by Rietveld analysis. The initial structural model and space group for the refinement is based on insight derived from earlier Mössbauer and TEM analyses. Refinement of the powder data leads to a tetragonal unit-cell with lattice parameters a=11.2260(2) Å and c=7.8731(2) Å in the space group P4/nmm. The refined compound is found to have a composition of NdNi 9.7Si 1.3B ∼4. The atomic coordinates for the Nd, Ni and Si atoms have been determined. Small amounts of the impurity phases, NdNi 5 and Nd 3Ni 13B 2, have also been determined and refined in the analysis.

An oscillation data collection system for high-resolution protein crystallography

An oscillation data collection system for protein crystallography is described. The system consists of a modified Enraf-Nonius precession camera with cylindrical cassette, and stepping motor driven by a flexible microprocessor control system. The X-ray source is graphite-monochromatized radiation from an Elliott GX-21 rotating-anode generator run at 5.5 kW on a focal spot measuring 0.5 × 5.0 mm. The potential advantages of using a relatively large focal spot in conjunction with a graphite monochromator are discussed. Conditions for optimum collimation and X-ray intensity are considered, and it is shown that appropriately designed collimators with adjustable apertures can have substantial advantages over commercially available pinhole collimators. The oscillation films are processed by a procedure based on that of Rossmann [J. Appl. Cryst. (1979), 12, 225-238]. Determination of the initial alignment of the film is facilitated by a pair of reference pins incorporated in the cylindrical cassette. These pins ensure that the position of the film in the cassette is known, and avoid the need for fiducial marks. The crystal alignment and film measurement technique is fully automatic, requiring no prior input other than the approximate starting orientation of the crystal, the approximate unit-cell dimensions, and the angular oscillation range. An alternative method for the determination of crystal orientation is proposed which has been found to be somewhat superior to that of Rossmann, especially for smaller unit cells.

Slow-neutron multiple scattering in liquid helium

The use of a semi-analytic method for making multiple scattering corrections in slow-neutron scattering work is illustrated by applying the method to a detailed calculation of the multiple scattering in liquid helium. It is assumed that the liquid helium sample is contained in a cylindrical cassette which is partitioned with absorbing spacers and the calculations are performed for conditions appropriate to triple-axis crystal spectrometry at Chalk River Nuclear Laboratories.

An X-ray powder camera attachment for preferred orientation investigations

An accessory for a Philips type, 11-46 cm diameter, powder camera has been constructed to facilitate the study of preferred orientation in polycrystalline specimens. The device takes the form of a cylindrical cassette which is a push fit on to the beam trap. Reference is made to its use in studying orientation in samples of pyrographite.

A low temperature Weissenberg camera

Details of the design and operation of a Weissenberg camera suitable for x-ray investigations between -180° c and 200° c are presented. The camera employs a novel arrangement of spur and bevel gears to couple the goniometer spindle to the worm rod which controls the range of oscillation. The entire drive system and the goniometer assembly are mounted on a support which permits the insertion or removal of a cylindrical cassette from the gear-box side without disturbing the cooling assembly and the layer-line screen. The cassette can also be inserted from the opposite side. The specimen can be cooled either directly by a stream of liquid air or by the cold gas from its evaporation. Condensation of moisture at low temperatures is prevented by heating the layer-line tubes internally.

X-ray Continuous Analysis

For the purpose of obtaining characteristic X-ray patterns continuously from an arbitrary line element on the surface of a specimen having some local irregularities or changes, a camera of a new type has been designed. This camera is cylindrical, inner diameter 54 mm, outer 60 mm and length about 80 mm, and the primary X-ray beam is introduced parallel to the cylinder-axis but 10 mm apart from it. Both pinhole-system and cylindrical shield are fixed, while cylindrical cassette for photographic film, and cylinder cap for specimen are capable to rotate about the cylinder axis as ore body. The photographic film is inserted innerside of the cassette which is then covered by the cap. The specimen is fixed to the stem, of which the axis coincides with the rotating axis and which is faced to the cap. The shape of such specimen is of a truncated circular cone, and every part on the surface of the zone 10 mm apart from the axis is irradiated by the X-ray beam through the pinhole-system, fixed to the camera body. In order to protect the photographic film from undesirable blackening, both the pinhole-system and the specimen are covered by the cylindrical shield having a long slit, 1 mm in width and parallel to the axis. When the specimen and the photographic film are rotated during the exposure, the obtained patterns will take the form of several continuous lines.These characteristics of this camera were confirmed by an experiment on partly hardened steel obtained using high frequency induction. In this way the present author has obtained patterns consisting of nearly straight lines having several diffuse and broken parts due to irregularities in the irradiated parts of the specimen.