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Conformity of tumour volumes and dose plans in prostate brachytherapy (BT) can be constrained by unwanted needle deflections, needle access restrictions and visualisation limitations. This work validates the feasibility of teleoperated robotic control of an active steerable needle using magnetic resonance (MR) for guidance. With this system, perturbations can be counteracted and critical structures can be circumvented to access currently inaccessible areas. The system comprises of (1) a novel steerable needle, (2) the minimally invasive robotics in an MR environment (MIRIAM) system, and (3) the daVinci Research Kit (dVRK). MR scans provide visual feedback to the operator controlling the dVRK. Needle steering is performed along curved trajectories to avoid the urethra towards targets (representing tumour tissue) in a prostate phantom with a targeting error of 1.2 ± 1.0 mm. This work shows the potential clinical applicability of active needle steering for prostate BT with a teleoperated robotic system in an MR environment. [ABSTRACT FROM AUTHOR]

Steerable instruments allow for precise access to deeply-seated targets while sparing sensitive tissues and avoiding anatomical structures. In this study we present a novel omnidirectional steerable instrument for prostate high-dose-rate (HDR) brachytherapy (BT). The instrument utilizes a needle with internal compliant mechanism, which enables distal tip steering through proximal instrument bending while retaining high axial and flexural rigidity. Finite element analysis evaluated the design and the prototype was validated in experiments involving tissue simulants and ex-vivo bovine tissue. Ultrasound (US) images were used to provide visualization and shape-reconstruction of the instrument during the insertions. In the experiments lateral tip steering up to 20 mm was found. Manually controlled active needle tip steering in inhomogeneous tissue simulants and ex-vivo tissue resulted in mean targeting errors of 1.4 mm and 2 mm in 3D position, respectively. The experiments show that steering response of the instrument is history-independent. The results indicate that the endpoint accuracy of the steerable instrument is similar to that of the conventional rigid HDR BT needle while adding the ability to steer along curved paths. Due to the design of the steerable needle sufficient axial and flexural rigidity is preserved to enable puncturing and path control within various heterogeneous tissues. The developed instrument has the potential to overcome problems currently unavoidable with conventional instruments, such as pubic arch interference in HDR BT, without major changes to the clinical workflow. [ABSTRACT FROM AUTHOR]

This paper explores the possibilities of using a graphics processing unit for complex 3D finite difference computation via MUSTA-FORCE and WENO algorithms. We propose a novel algorithm based on the new properties of CUDA surface memory optimized for 2D spatial locality and compare it with 3D stencil computations carried out via shared memory, which is currently considered to be the best approach. A case study was performed for the extensive generation of a time series of 3D grids of arbitrary size used in the computation of collisions between heavy nuclei in terms of relativistic hydrodynamics. It proved that implementation based on surface memory is as much as 23% faster than an equivalent implementation using shared memory. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper presents the results of the first isotopic investigations of sediments recovered from Lake Wigry (NE-Poland). In the spring/summer 2002 few sediment cores, plant samples and water profiles were collected specially for isotopic investigations. We obtained 210Pb activity profiles, 137Cs activity profiles and 14C activity/age profiles. Apparent ages of carbonate fraction for all sediment cores were determined. Sedimentation rates for collected cores were estimated using 14C dating method. In addition oxygen isotopic ratios of the water profiles, carbon stable isotopes ratio of collected sediment cores were determined. [ABSTRACT FROM AUTHOR]

Presents information on a study which describes the development of an intrapartum intervention score used to quantify the degree of intervention in childbirth. Methodology of the study; Results and discussion on the study.

The skin abrasion technique has been used to measure the inflammatory exudate levels of cefa.zolin and cephaloridine in patients undergoing elective surgery. These levels were compared with serum and wound concentrations. Inflammatory exudate concentrations of both antibiotics were almost identical to serum concentrations and considerably higher than the measured wound concentrations. For cephaloridine, peak concentrations in serum and exudate were reached synchronously. For cefazolin the transfer from serum to inflammatory exudate was significantly delayed. Therefore, the skin abrasion technique, in conjunction with serum concentrations gives additional information about antibiotic transport in man. In inflammatory exudate, serum and wounds, cefazolin achieved higher concentrations than did the same dose of cephaloridine. [ABSTRACT FROM PUBLISHER]

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A study of the structure of cotton fibres is described, the objective being to determine whether differences in properties between cotton types can be attributed to differences in structure, primarily at the molecular or supramolecular level of organization. It is concluded that there are no obvious differences in the nature of the crystallographic units or the supramolecular 'crystalline aggregates' between cotton varieties and that the observed differences in mechanical properties must have been due to the arrangement of these units (e.g., orientation) or to differences at higher levels of structural organization. [ABSTRACT FROM AUTHOR]

An account is given of an investigation in which the variation in the frictional forces developed along the surface of some Egyptian cotton fibres was measured over a range of the recorded normal-load values developed under the point-point conditions of contact with a straight-edge probe. It is evident from the video-tape recordings made that the frequency of convolutions in cotton fibres is primarily responsible for determining their frictional behaviour. Under the experimental conditions used, the frictional force varies linearly with the normal load, and no evidence of plastic deformation was observed within the limit of resolution of the scanning electron microscope. [ABSTRACT FROM AUTHOR]

The paucity of information about the fine structure of cuticle cells, in animal hair and wool fibres, has been a major factor in the general failure to advance a theory capable of explaining quantitatively the origin of the Directional Frictional Effect. Electron microscope studies have been made covering : (i) surface replications, (ii) examination of fibre profiles, and (iii) thin sectioning. Significant differences have been found between the surface textures of replicas of various wool fibres. However, because of the lack of equipment for the quantitative interpretation of stereo electron-micrographs, the direct examination of fibre profiles was undertaken. Thus, information was obtained about the height and frequency of the distribution of cuticle cell edges along the fibre axis, together with other information about the surface asperities. Thin sections (both transverse and longitudinal) yielded information about the type and extent of radial and peripheral overlapping of cuticle cells ; also, the various ways in which they are attached to their neighbours. The idealized model of a cuticle cell, emerging from these studies, could account for the two distinctly different mechanisms of deformation, namely buckling and compression, under forces acting in the direction of fibre-root and fibre-tip respectively. Evidence was obtained providing further, if not conclusive, proof of the "ploughing" action, operative during motion in the tip-to-root direction. [ABSTRACT FROM AUTHOR]

The equatorial scatter of X-rays by Lincoln wool fibres stretched in water at room temperature by extensions up to 60% has been recorded using a Huger counter diffractometer. The results agree with those of Bendit in establishing that there is an important change in the scattering at extensions less than 20%. The changes have been analysed on the assumption that they are the result of a single phase transformation from crystalline α-keratin to crystalline β-keratin, and the rate of change of each component has been derived. It is found that there is a deficit in the total amount of crystalline keratin except in the unstretched and fully stretched conditions, indicating that an intermediate state exists in which the keratin is not sufficiently well-ordered to contribute to the 10Å or 4.65Å equatorial peaks. The difficulty of transforming the Pauling and Corey AB6 cable is recalled, and the possibility of packing of coiled-coil α-helices without their forming twisted cables is pointed out. [ABSTRACT FROM AUTHOR]

The X-ray diffraction of reduced Lincoln wool fibres containing silver taken up from silver nitrate solution is almost entirely confined to angles less than approximately 6° from the main beam. An analysis of the meridional reflections, whose spacings represent the 3rd to 10th orders of 198Å, by constructing a one-dimensional Patterson function, indicates that there is a probable periodicity of 25Å along the fibre axis. Silver, like osmium, is successful in showing up the microfibrillar texture in electron micrographs of thin transverse sections; and in fibres disintegrated by grinding in lithium bromide solution, microfibrillar sheets are observed in which the silver-stained matrix between the microfibrils has a pseudo-globular appearance. Both silver and mercury are taken up by the microfibrils as well as by the matrix, and neither appears to be a specific stain for sulphur. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented about a paper entitled "Electron-Microscopy of Degraded Cellulose Fibers," by S. M. Mukherjee, J. Sikorski and H. J. Woods.

The article details the construction of a photographic recording extensometer which has been found to be satisfactory for textile fiber research. The apparatus is based on the same principle as the Lonsdale extensometer, but several important changes have been introduced including the incorporation of an electric drive with reserving mechanism and increased range of adjustment of the sensitivity of the balance. The main characteristic of the apparatus is its adaptability. The many applications of the extensometer are illustrated by typical load/extension and recovery curves at constant rates of loading and of extension, a relaxation curve at constant extension and records of the frictional forces between fibers and solid surfaces.

An account is given of experiments in which wool fibres were subjected to a large variety of chemical treatments considered as being representative of those commonly used in industrial finishing. For treatments designed to produce shrink-resistance, samples of similarly treated fabrics, subsequently subjected to a felting test (based on the International Wool Secretariat Specification 7), showed the area shrinkage to be within acceptable limits. Qualitative scanning-electron-microscope studies revealed relatively little damage to the surface topography of wool fibres when treatments were applied at the ‘normal’ level. When some of the treated fibres were subjected to a wash test (International Organization for Standardization No. 2), partial fragmentation of the cuticle occurred after chlorination and bleaching with hydrogen peroxide. However, little damage was observed after the wash test made on fibres treated at ‘normal’ levels. [ABSTRACT FROM AUTHOR]

The relation between the creep behaviour (plasticity) and the proportion of the orthocortical material (expressed as ortho/para ratio) in five lambs' wools has been examined by means of electron-microscope techniques, in conjunction with thin sectioning. No correlation was found between the amount of orthocortical material, on the one hand, and either plasticity or helical conformation (the latter estimated by other workers) on the other. These results are supported by the observation of the structural differences, greater than hitherto thought, within both cortical segments (as indicated by the considerable variation in metal absorption—'staining'), and it is believed that these have the primary effect on the plasticity. The cells of intermediate morphological appearance and reactivity (between those of the two bilateral segments and referred to as meso-type) have a secondary influence in this respect. [ABSTRACT FROM AUTHOR]

Editorial. Deals with the outcome of treatment to patients with fractures on the proximal femur. Determinant of treatment outcomes; Members of the disciplinary team in charge with the treatment of proximal femoral fracture patients; Discussion on the ethical implications of length of hospital stay.

A letter to the editor and a response by the authors on their article "Electron-microscopy of Degraded Cellulose Fibers," published in the previous issue are presented.

The article discusses the morphology of the cuticle layer in wool fibers and other animal hairs. After examining surface textures, fiber profiles and thin sections using electron microscopes, significant differences between the surface textures of replicas of various wool fibers were found. Direct examination of fiber profiles obtained information on surface asperities, height and frequency of the distribution of cuticle cell edges along the fiber axis. Type and extent of radial and peripheral overlapping of cuticle cells and their attachments to other was examined using transverse and longitudinal thin sections. The author concludes that the two distinct mechanisms of deformation are buckling and compression supported by the idealized model of a cuticle cell.

A letter to the editor is presented in response to an article on solving the structural complexities of mammalian keratin.