bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption Study of 47 Elements on Alumina and Bentonite Using a Multitracer Technique
Authors: Jinzhou Du , Xinmin Yin , Xiangke Wang , Xing Dai Xiong , Xiang Zhang , Tongyu Sun , Zuyi Tao
Published: January 2017

Uranyl nitrate, UO2(NO3)2, was irradiated with a 25 MeV/nucleon 40Ar ion beam, and the target material removed by means of solvent extraction. A radioactive multitracer solution containing 47 elements and 83 nuclides free from carriers was thereby prepared. The multitracer solution was used in an adsorption study of 47 elements on alumina and bentonite. The distribution coefficients (Kd) of the 47 elements were simultaneously determined and correlated with the electron binding energy (Iz), and explained by the thermodynamic model for adsorption of James and Healy (1972).
Low-Temperature IR Spectroscopy of CO Adsorption on Calcined Supported CeO2: Probing Adsorbed Species and Adsorbing Sites
Authors: Mekhemer Gamal A.H. , Zaki Mohamed I.
Published: January 2017

Carbon monoxide adsorption on ceria dispersed on silica (CeSi) and alumina (CeAl) at 300–80 K was observed by in-situ IR spectroscopy. For control purposes, CO adsorption was also observed on unsupported CeO2 and the individual support materials (SiO2 and Al2O3). The adsorbents were prepared ex situ by heating at 770 K (3 h) in air, and pretreated in situ by heating at 720 K (1 h) in oxygen and then in vacuum. The results, as disclosed by v(OH) (3900–3300 cm−1) and v(CO) (2250–2050 cm−1) spectra taken before and after CO adsorption, reveal that CO adsorbs on all of the test adsorbents at temperatures < 300 K only. The resulting adsorbed species include CO coordinated to Lewis acid sites (on all of the adsorbents, but not SiO2), hydrogen-bonded CO (on all of the adsorbents, but not CeO2) and CO bound to electron-rich defect sites (only on unsupported CeO2). It is concluded that the dispersion of ceria, particularly on alumina, is associated with a considerable development of the Lewis acidity of Ce4+ sites.
A Multi-Stage Batch Sorption Design with Experimental Data
Authors: Ho Y.S. , McKay G.
Published: January 2017

The sorption of lead ions on to peat in an agitated batch adsorber has been studied. A model has been developed for the design of a two-stage batch adsorber based on pseudo second-order sorption kinetics. The model has been optimised with respect to contact time in order to minimise total contact time to achieve a fixed percentage of metal ion removal.
Synthesis and Characterization of Ti—MCM-41-Type Mesoporous Molecular Sieves with High Titanium Contents
Authors: Kovalenko A.S. , Korchev A.S. , Chernenko J.V. , Il'in V.G. , Filippov A.P.
Published: January 2017

By employing a sodium silicate + titanium tetrabutoxide + trimethylmyristylammonium bromide system, it has been possible to obtain mesoporous titanosilicate Ti–MCM-41-type molecular sieves containing systematically varying titanium contents. The samples obtained possessed a high BET specific surface area and exhibited the perfect hexagonal mesoporous structure characteristic for MCM-41 materials even when the titanium fraction present was as great as 20 mol%. It has been shown that most of the titanium can be expelled from the structure when the materials are treated with sulphuric acid solution. However, such treatment does not destroy their inherent hexagonal structure, thereby suggesting that the titanium is preferentially localized in the mesopore surface layer. The structure/sorption properties of the materials were investigated by X-ray diffraction methods and by the adsorption of n-hexane and water vapour. A possible mechanism for the formation of such MCM-41-type molecular sieves is proposed which suggests that the use of organometallic ethers M(OR)n, accompanied by ether solubilization with organic micellar templates, leads to the preferential localization of M in the mesopore surface.
On the Pore Size Distributions and Fractal Dimensions of Activated Carbons Evaluated on the Basis of the Analysis of Nitrogen, Argon and Benzene Vapour Adsorption Data
Authors: Trznadel B.J. , Światkowski A.
Published: January 2017

The Dubinin–Stoeckli equation and the Horvath–Kawazoe equation have been used for the determination of the pore size distribution (PSD) for three fractions of activated carbon separated by elutriation due to their different degrees of activation (burn-off). A comparison of the PSD functions on the basis of nitrogen, argon and benzene adsorption isotherms has been undertaken. The general form of the Dubinin–Stoeckli equation has been developed for nitrogen and argon as an adsorbate. For all adsorbates studied, correction factors including adsorption in mesopores were introduced. New formulae for this correction factor have been proposed for nitrogen and argon. Quantitative evaluations of PSD functions for these three different adsorbates lead to the conclusion that it is possible to use the benzene isotherm as well as the nitrogen or argon isotherms to characterise the microporous structure of the adsorbent. Comparison of the porous structure parameters was extended by a fractal analysis.
Adsorption Mechanisms of Phenol and Methylphenols on Organoclays
Authors: Ceyhan Özlem , Güler Hülya , Güler Raif
Published: January 2017

Eight clay–organic complexes were synthesized by placing quaternary ammonium cations (QUATs) on to bentonite (B) and kaolinite (K) by cation exchange. The organic cations used were hexadecyltrimethylammonium (HDTMA), dodecyltrimethylammonium (DDTMA), trimethylphenylammonium (TMPA) and tetramethylammonium (TMA). These organoclays were characterized via their organic carbon contents with the aid of XRD and FT-IR spectroscopic analyses. The organoclays were examined for their ability to adsorb phenol (P) and several of its methyl congeners [2,4-dimethylphenol (2,4-DMP) and 2,4,6-trimethylphenol (2,4,6-TMP)]. It was shown that inorganoclays (Na–clays) and organokaolinites were incapable of adsorbing any of these organic pollutants. It was also determined that the adsorption of phenol compounds from water decreased in the order: 2,4,6-TMP > 2,4-DMP > P for HDTMA–B and DDTMA–B, 2,4-DMP > P > 2,4,6-TMP for TMPA–B and P > 2,4-DMP > 2,4,6-TMP for TMA–B. With n-hexane as a solvent a different adsorption trend was found, which depended on the type and degree of solvent interaction with the organic compounds and the organoclays. It was observed that the degree of adsorption of phenols on to organoclays was dependent on the relative adsorbent-adsorbate energies and adsorbate–solvent interactions. The adsorption isotherms of phenols on to organophilic clays were evaluated according to the Giles classification.
A Method for Generating Some Periodic and Quasiperiodic Space Lattices
Authors: Stuart Duncan R.
Published: January 2017

Some discoveries c. 1960 concerning the ordered structure of points, lines and planes in space known as space lattices appear to offer some interesting but as yet untried possibilities for the enhancement of the design of physical artifacts. Confirmation that Nature employs at least some of the properties to be discussed has come to light in the discovery of a new form for matter referred to as the quasicrystalline state.

This paper describes a method for generating a group of such lattices. The number of possible ‘genotypes' appears to be, at least in theory, uncountable though only a few members of this multitude seem to offer the possibility of significant practical application. At least two of the genotypes appear to offer the designer a seemingly endless variety of possible form variants. This variation is achieved with a relatively low number of kinds of component parts, because for each genotype one needs only two facially identical equilateral but otherwise different rhombohedra.
Temperature Analysis of Pin-Jointed Spherical Domes
Authors: Gáspár Zs.
Published: January 2017

The stiffness matrix of a pin-jointed spherical dome is expressed in spherical coordinates and the load vector is derived for uniform change of temperature. This method of representation may be used when improving the best available estimates of the Tammes problem (How must n equal, non-overlapping circles be packed on a sphere so that the angular diameter of the circles will be as great as possible?).
Steel Dome of Jawaharlal Nehru Indoor Stadium
Authors: Subramanian N. , Ganguly K.K.
Published: January 2017

The main features of the tubular steel dome of 67m diameter covering the Jawaharlal Nehru Indoor Stadium at Cuttack, India, are presented. This dome is made up of 8 arch trusses of depth 1.2 m connecting at the crown of the dome. Another 8 tubular battens are provided for reducing the span of the purlins. These battens are connected to the top ring beam. A monitor of 18 m diameter is provided at the top for natural lighting. The dome is covered with aluminium sheets. At the time of completion, this was the largest diameter dome in India.
On Structural Redundancy in Space Trusses
Authors: Hanaor Ariel , Ong An-Fu
Published: January 2017

Static redundancy does not ensure structural redundancy in cases where the collapse mechanism involves instability. Structural redundancy is defined here as the ability of the structure to sustain its design load with the loss of one or more critical elements. The parametric investigations on a square on square double-layer grid presented here, suggests that the loss of one critical member from this type of structure typically entails a loss of 20% to 30% of load carrying capacity. To allow for structural redundancy, as well as for loss of carrying capacity due to the effect of imperfections, it is recommended to reduce compression members' buckling (or allowable) stress by a corresponding value or, alternatively, to perform a suitable analysis.
Double Layer Grid Space Frame Buckling
Authors: Murtha-Smith Erling , Bean John E.
Published: January 2017

The general problem of the buckling of space frames has been simplified for the case of double layer grid space frames making assumptions regarding the mode of buckling. These assumptions allow simple single joint equivalent substructures to be used and solved using stability functions with a single equation for each mode each involving only one variable, the load level. Typical cases are examined. In addition, the method is applied to existing experimental results and shows very good agreement. The method can be applied to the practical design of double layer grid space frame members. In addition, this method could be combined with a nonlinear space truss analysis to determine the member capacities as nonlinear behaviour develops.
Predicting Collapse of a Lattice Dome Due to Foundation Settlement
Authors: Shugar T.A. , Holland T.J.
Published: January 2017

The base of the lattice dome sheltering the Amundsen-Scott South Pole Station is distorting due to movement in the compacted snow foundation. The base ring differential settlement is calculated by a least squares analysis of measured foundation displacement data. The topology and geometry of the dome have been reconstructed, and a one-to-one correspondence exists between the modeled and actual latticed framework. A structural model based on bending elements is employed and its development is discussed relative to an alternative, non-bending model.

Practical structural analysis issues for predicting collapse of a lattice dome due to settlement using modern computer methods are discussed. Attempts to calculate post-buckled configurations and the collapse load of the structure were only partially successful. However, application of these methods to the South Pole Dome show that it is in satisfactory condition at its present level of differential settlement.
Torus Gesto Space Structure System
Authors: Georgievski Vladimir
Published: January 2017

The paper presents the details of the TORUS GESTO system of space structures developed in the Institute of Welding and Welded Constructions at the Department for Metal Structures at the Faculty of Mechanical Engineering, Skopje, Yugoslavia.

It contains a brief description of a recent application of a new system of construction used for a large storage hall and discusses the advantages and disadvantages of the system. After the details of the development of the TORUS GESTO jointing system, the article deals briefly with the production technology, erection procedures and full-size tests of space structures constructed in this system.
Comparative Evaluation of Construction Systems of Lightweight Space Structures
Authors: Karni Eyal , Burt Michael , Czamanski Daniel
Published: January 2017

The paper presents a new approach to help designers and developers select the most appropriate light-weight space structure construction system for a specific project. The new approach makes possible a comparative evaluation of the available construction systems, in light of project's constraints and objectives. The decision maker is provided with a ranking of the alternate construction systems respectively.
Tension Truss Concept and Formation of Geodesic Shapes in Space
Authors: Miura Koryo
Published: January 2017

This paper presents the basis of tension truss concept for formation of a geodesic shape in space by a tensile structure. The geodesic shape in architecture is usually formed by triangulated rigid truss members. The concept of tension truss, proposed by the present author, consists in tensioning a triangulated cable network to form a rigid geodesic shape in 3-space. The compact packaging, lightweight, and simplicity in joints design can be achieved by this concept. Since the surface shape is uniquely determined by lengths and the arrangement of cable truss members, the shape adjustment can be done easily. These characteristics are well fitted for very large space-borne antenna reflectors, and the developmental efforts are currently done in my institute aiming at a large deployable antenna of the mission called space VLBI. The current result is reported in this paper. In general, the present concept opened the way anew for construction of tensile structures in a shape having positive Gaussian curvature.
Tensegrity Systems and Geodesic Domes
Authors: Motro R.
Published: January 2017

The name Buckminster Fuller is associated with the development of geodesic domes and with tensegrity systems. The principle of the latter is that rigidity is obtained by selfstressing alone. The shapes of domes constructed using tensegrity systems are not generally known a priori; these domes belong to the class of systems with indeterminate shape, such as cable systems. A form-finding method using the dynamic relaxation technique with attenuation of kinetic energy is presented here. The results given by this general method are compared with known solutions in certain cases and make it possible to quantify the deviations between geometries of tensegrity systems and polyhedral geometries.

An example is given to illustrate the possibilities of the combination of the principle of tensegity systems with that of geodesic domes. It is a double-layer, double-curvature system whose shape respects the selfstressing criterion. Industrial construction of the system can be envisaged thanks to the design of an assembly node which permits variations in curve radius.
Effects of Tension and Configuration in Surface Errors of Membrane Space Antennas
Authors: Furuya Hiroshi , Miura Koryo
Published: January 2017

In the recent studies on large space antennas, it is expected that they are made up of a metallic mesh or a membrane into a parabolic surface. Such a membrane surface, that has a curved boundary, forms a kind of hyperbolic paraboloid surface. From this result, the root mean square errors of the antenna between the best fit parabola (BFP) and the real surface are increased. The purpose of the present study is to determine the effects of tension on surface errors, and its contour configuration with a parabolic boundary. There are two methods to control the deformation of membrane type surface: a boundary segment geometry and a distribution of a tensile force. The modeling formulations of the general membrane surface, surface configurations and tolerances caused by the boundary segment configuration and tension ratio, are established.
Geometry of Spatial Folded Forms
Authors: Tonon Osvaldo L.
Published: January 2017

A series of interesting spatial forms can be created by means of the folding of laminar plane elements. This paper illustrates methods to describe and solve some of them from the geometric point of view, taking the analysis towards those forms which have their origin in bellows type folds.
A Fast Algorithm for Periodic Structures in Vibration
Authors: Leung A.Y.T. , Wong S.C. , Lee P.K.K.
Published: January 2017

Periodic structures are popular in engineering applications for economical and architectural reasons. A fast method for calculating the natural vibration of periodic structures having identical constituents (substructures) with general boundary conditions is introduced. The number of arithmetic counts is proportional to PlogP, instead of P2 in the conventional method with band solver, where P is the number of substructures involved. Because of the fact that the general boundary conditions have been considered, a periodic structure can be represented by its condensed matrices associated with the boundary stations to form a superstructure which can be connected to other structures. Four illustrative examples are given.
Formex Formulation of Transmission Tower Structures
Authors: Al-Bermani F.G.A. , Kitipornchai S. , Chan S.L
Published: January 2017

The formex formulation of the topological configuration, geometry, load and support conditions of self-supporting or free-standing transmission towers is presented. In the formulation, a natural normat coordinate system is used. The tower topology is formulated according to member types and orientations within the tower. The formex formulation is implemented as a preprocessor for a general elasto-plastic nonlinear large displacement analysis program for transmission tower structures. The data generated from the formex formulation is transformed into an AutoLISP file that can be loaded and used by AutoCAD. Throughout the paper, it is assumed that the readers are familiar with the basic concept and terminology used in formex algebra.
Geometrical Shaping of Reticulated Shells
Authors: Saveljev V.A.
Published: January 2017

The problem of geometrical shaping consists of the construction of an abstract mathematical model representing a geometrical diagram of the structure. The paper considers the methods of geometrical construction of single and double-layer reticulated surfaces with equilateral quadrangular and hexagonal cells.
Shape Formation of Stereometric Dome Shells
Authors: Zubkov V.V.
Published: January 2017

Theoretical fundamentals of shape formation of stereometrical dome shells are revealed in this article. The genesis of shapes of shells consisting of plane elements of regular configuration in the form of truncated parts of regular polyhedrons is also considered. Principles of geometric formation of shell shapeil structures are touched upon and a brief description of each of them is given from the point of view of possible unification of shape forming elements. The author develops a methodology for designing stereometrical dome-shaped shells on the basis of regular crystals. He also describes methods of geometric calculation of stereometrical dome-shaped shells. Some methods of construction of shell surfaces and various kinds of compositions derived from them are demonstrated. Brief data on the peculiarities of material utilisation of stereometrical dome shells and some examples of their application in architecture are given.
Concept of Deployable Tensegrity Structures in Space Application
Authors: Furuya Hiroshi
Published: January 2017

This paper proposes a concept of deployable tensegrity space structures in future aerospace activities to avoid some difficulties of conventional deployable space structures. The fundamental geometrical characteristics for deployment of tensegrity masts are introduced. Some conceptual considerations for the one-dimensional deployable tensegrity are presented from the viewpoint of geometry. The conceptual model of one-dimensional deployable tensegrity truss mast was constructed to demonstrate the concept. Some vibrational characteristics for various type of one-dimensional tensegrity truss mast were also examined.
A Study of Morphological Characteristics of Tensegrity Structures
Authors: Chassagnoux A. , Chomarat A. , Savel J.
Published: January 2017

Tensegrity structures have a special place in the structures classification. Some developments by D.G. Emmerich on their morphology show their important diversity in their geometrical configurations.

In this study, the authors describe the mathematical relationships that determine the spatial organisation of the tensegrity structures components and demonstrate that these structures represent the particular characteristics at the origin of mechanisms which transform themselves into stable structures as soon as they are loaded.
A Study of the Behaviour of Joints
Authors: Zhao H.L. , Ma J. , Yan S.R.
Published: January 2017

The present paper describes the behaviour of three types of joints based on the elasto-plastic theory. A computer program has been developed to perform materially nonlinear analysis of these nodes. One-dimensional loading tests are also described and close agreement between the analytical and experimental results is achieved.
Deployable Modular Mesh Antenna and its Surface Adjustment
Authors: Mitsugi J. , Yasaka T.
Published: January 2017

The deployable modular mesh antenna is composed of independently fabricated and tested antenna modules to reduce difficulties in ground testing. Each module comprises a metallic mesh shaped by a cable nework and a deployable truss structure. This paper states the basic constitution of each module, especially of the cable network, and results of surface shape adjustment simulations and experiments. Employing the present method, reflector distortions after the fabrication can be adjusted by changing cable lengths without any sensitivity analysis. Numerical simulations and experiments clarify that the attainable surface accuracy of a module is determined mainly by the accuracy of the truss structure.
A Single Die-Cut Element for Transformable Structures
Authors: Verheyen H. F.
Published: January 2017

Any polyhedral structure composed of identical regular polygons can be turned into an expandable structure by replacing the polygons by pairs of polygons which can rotate about a common central hinge, and connecting a vertex of an upper polygon with the vertex of a lower polygon of an adjacent pair. Most of these structures will collapse in the fully expanded position by losing their rigidity near the final stage, and hence, become deployable. A triangular element which enables one to assemble and dismantle such structures is presented here, together with a series of examples of experimental shapes.
Exact Parametric Study Giving Insight into Dome Vibrations
Authors: Williams F.W. , Jemah A.K. , Song L.M. , Kennedy D.
Published: January 2017

A parametric study is presented of the undamped free vibration of a one layer truss type circular dome, with terrestrial proportions. The dome is composed of 36 identical portions, but is supported at only 4, 6, 9, 12, 18 or 36 uniformly spaced points. Only one of the 36 portions is needed in the analysis, using the large space frame computer program BUNVIS-RG, which can analyse linearly repetitive or rotationally periodic structures ‘exactly’, e.g. without the usual finite element discretisation approximations. The study includes changing: the height to diameter ratio; the number of supports; the type of supports; and the type of joint from rigid to pinned connections. In addition, modal densities are found for a near optimum dome. The method used gives valuable insights into the exact mode shapes by showing that they are always composed entirely of a (usually short) finite series of circumferential sine waves.
Shape Formation of Deployable Metal Domes
Authors: Schmidt Lewis C. , Li Hewen
Published: January 2017

This paper presents a new approach for forming and erecting deployable metal domes. The approach is basically one where the whole structure is assembled initially at ground level in an essentially flat condition. By the use of appropriate post-tensioning, the space structure can be erected and shaped simultaneously. Based on previous studies on deployment principle and geometric models, this paper present an approach to investigate the appropriate way of post-tensioning for the shape formation and erection of the metal domes by means of finite element analyses. An example is given to illustrate the main steps in shape formation of the deployable metal domes, and the results of the example show that this new approach is reliable and feasible. Potentially, the procedure can offer economies over traditional methods of construction of such structures.
Thin Sheet Metal (Membrane) Suspended Roof Structures
Authors: Yeremeyv P.G. , Kiselev D.B.
Published: January 2017

A membrane roof is a three-dimensional system of thin metal sagging sheets fastened along the perimeter to the supporting contour. The membrane can form the roof of buildings and structures of various shapes of the surface and in-plan outlines with spans of 18 to 300 m. The longer the span the higher the economic efficiency of the membranes, the thickness of which is as low as 1 to 5 mm.

The distinctive features of the structure are the most complete use of strength properties of a thin sheet in compression and the continuation in one material of load bearing and enclosure functions. Such a structure is able to resist all types of force actions, wind and seismic ones being among them.

The thin-sheet roof are easy to manufacture and erect.

The membrane structures are intended for civil and industrial buildings.

At present a wide complex of theoretical and experimental studies of the membrane structures is being carried out.
Composite Suspended Shells on Cyclical Plan
Authors: Tärno Ülo A. , Zhukovski Ernest Z. , Shevtshenko Olga V.
Published: January 2017

The problems connected with the research of rational types of reinforced concrete shell roofs satisfying the demands of city-planning, functional, economic and technological requirements were under investigation during the last decades in TTU and MNIITEP. This paper suggests the use of composite suspended polygonal shells. The structures consist of the curvilinear plates and systems of radial two-level supporting elements. 5 and 12 angle structures were created for the investigations of stress-strain conditions of the complex roofs. The experiments were carried out on fiberglass plastic models and results assure the possibility to use such structures.
Frequency Domain Dynamic Analysis of Large Space Structures with Added Elastomeric Dampers
Authors: Horr A.M. , Schmidt L.C.
Published: January 2017

Modern computer-based computational techniques such as the finite element method enable the structural dynamicist to make precise calculations of the mass and stiffness properties of complex large space structures (LSS). To obtain dissipation analysis up to the same level of sophisitcation as mass and stiffness analysis in damped structures, an equally accurate methodology is required. This paper presents one such methodology for LSS with added elastomeric dampers. Elastomeric dampers have been used in the different parts of LSS to absorb part of the vibrational energy, and to help reduce the damage caused by the dynamic forces. The purpose of this paper is to present the specturally formulated finite element analyses for damped LSS. Using the fractional derivative model, the non-linear damping characteristics of elastomeric dampers have been modelled.
Torsional Analysis of Lattice Towers
Authors: Cao J.J. , Bell A.J. , Xu K.J.
Published: January 2017

This paper is concerned with the calculation of forces and displacements arising from the torsion loading of lattice towers. Square, rectangular and triangular towers with parallel legs, sloping legs and combinations of parallel/sloping legs are considered. New formulae are presented for determining forces and displacements based on formulae similar to those used in torsional theory of thin-walled bars. The formulae are simple and accurate and can be used in practical situations, particularly at the initial design stage or during reassessment of structures for revised loading. The accuracy of the formulae has been confirmed by finite element analysis. Two examples are included to demonstrate the use of the formulae.
Integral-Tension Research in Double-Layer Tensegrity Grids
Authors: Wang Bin-Bing , Liu Xi-Liang
Published: January 2017

In this paper, the concept of integral-tensioning continuous cables for prestressing double-layer tensegrity (DLTG) grids is presented and its principles are discussed. A simple approach for analyzing its properties is also recommended. Among three possible integral-tension methods, the optimal is selected. The method avoids the drawbacks of the conventional prestressing methods of bar elongation, simplifies the connections between bars and cables, and produces excellent load-carrying capacity. When large grids are constructed, optimal design can be achieved.
Preliminary Results of PTFE Patch Saphenoplasty to Prevent Neovascularization Leading to Recurrent Varicose Veins
Authors: Earnshaw J. J. , Davies B. , Harradine K. , Heather B. P.
Published: January 2017

Objective:

Recurrence is common after varicose vein surgery. Neovascularization may be one cause of recurrent veins. This was a study of PTFE patch saphenoplasty to try and prevent recurrent veins.

Design and setting:

Prospective cohort study of patients treated in a vascular surgical unit.

Patients and interventions:

Fifty patients having surgery for symptomatic long saphenous varicose veins (66 legs, 51 primary and 15 recurrent veins) had a PTFE patch sutured over the saphenous opening after flush saphenofemoral ligation.

Main outcome measures:

The rate of varicose vein recurrence and neovascularization 1 year after surgery were determined using clinical examination and venous duplex imaging.

Results:

Forty patients (80%) remained pleased with the results of their surgery. Recurrent veins were visible in 14 (21%) legs: 10 were principally due to neovascularization, two to sapheno-popliteal incompetence and two to an incompetent mid-thigh perforating vein. Three other legs had neovascularization but no recurrent veins. Both recurrent veins (47% versus 14%) and neovascularization (40% versus 14%) were significantly more common in patients having surgery for recurrent veins.

Conclusions:

PTFE patching was safe but did not abolish neovascularization. Neovascularization was the principal cause of recurrent veins in this study and perseverance with investigations into other barrier methods is worthwhile.
The Clinical and Histological Effects of Ethanolamine in Varicose Veins
Authors: Mosley J. G. , Gupta I.
Published: January 2017

Objective:

To study the histological changes in varicosities after injection of 5% ethanolamine.

Design:

A prospective study in nine groups of six patients awaiting bilateral varicose vein surgery.

Patients:

Each patient had a below-knee incompetent perforating vein injected with either 0.5, 1.0 or 2.0 ml 5% ethanolamine. The contralateral varicosity received a similar volume of normal saline.

Intervention:

The patients wore elasticated stockings until admitted for operation at 2, 4 or 8 weeks after the injections. The injected varicosity was then dissected out.

Main outcome measures:

Each vein was reported on by a histologist who did not know which had received ethanolamine or saline. The histologist graded each vein according to the severity of change from 0 (no effect) to 5 (total obliteration of vein).

Results:

Ethanolamine at 0.5, 1.0 and 2.0 ml caused extensive histological damage to the varicosity. After 8 weeks most varicosities had been destroyed.

Conclusion:

Ethanolamine, unlike sodium tetradecyl sulphate, causes complete destruction of a varicosity. A dose of 0.5 ml is just as effective as 2.0 ml.
Neonatal Renal Vein Thrombosis: Report of a Case
Authors: Bohórquez-Sierra J. C. , Calvo-López M. J. , Martínez-León J. I. , Rodríguez-Piñero M. , Arribas-Aguilar F. , Bohórquez-Sierra C.
Published: January 2017

Objective:

To report a case of neonatal renal vein thrombosis diagnosed by duplex scan and treated successfully with intravenous heparin.

Design:

Case report.

Setting:

Angiology and Vascular Surgery Unit, Hospital Universitario Puerta del Mar, Cádiz, Spain.

Interventions:

Conservative treatment with short-term intravenous heparin.

Conclusions:

Colour Doppler imaging rapidly assesses flow within the renal veins and inferior vena cava, and should be used as the first line of investigation in evaluating venous thrombosis in the neonatal period. In view of the few reports in the literature assessing the different therapeutic modalities of this entity, we advocate short-term anticoagulation in unilateral renal vein thrombosis in the newborn.
The super-centralisation of the English state – Why we need to move beyond the devolution deception
Authors: Hambleton Robin
Published: January 2017

In a stream of high-profile announcements, the UK central government has said that it wants to devolve power to sub-regions within England – to city regions and across the country. This article presents evidence to show that the actual intent of government policy is the reverse. Instead of promoting the creation of powerful, independent sub-regional authorities, answerable to the citizens who elected them, the government is seeking to impose a super-centralised model of decision-making in which locally elected politicians are required to comply with central directives. By drawing on work with city region leaders in England, the article develops criteria for assessing sub-regional governance. Inspirational examples of city region governance in other countries are presented. These examples show that the current super-centralisation of the English state is out of step with progressive policy making in other countries. Suggestions on how to develop real devolution in England are outlined.
Rural–urban business partnerships—Towards a new trans-territorial logic
Authors: Hjalager Anne-Mette
Published: January 2017

These years, rural–urban business partnerships emerge in a new trans-territorial logic, surpassing normal trade alliances. Such partnerships embrace social issues, benefits related to place branding, knowledge dissemination, etc. This contribution scrutinizes 11 rural–urban business partnerships in Denmark within fields of food, film, green care, media, retail, teleworking, education, and tourism. The degree of structural and legal formalization varies, but in many cases the formalization is fairly low. Partnership transparency formats depend on interrelationships with volunteering communities. When analyzing resource composition of the rural–urban business partnerships it becomes clear that there are multi-faceted value flows consisting of products, production capacity, market access, knowledge, capital, waste products, and amenities. The creation of productive business partnerships often takes a long time, and they are matters of continual change. The successful examples transform positively the value chain and rearrange the nature and power of transactions in a territorial framework, and they accommodate for entrepreneurial forces in disadvantaged regions.
The Modelling of Threats: Evidence from the British Crime Survey
Authors: Tseloni Andromachi , Osborn Denise R. , Pease Ken
Published: January 2017

Threats to kill, to injure, or to damage property stimulate fear and anxiety in the victim and his/her immediate human environment. Previous research has used sociodemographic attributes and lifestyle or routine activities measurements to predict crime victimisation rates. The purpose of this study is to examine how personal characteristics are associated with the probability of being threatened. Data from three sweeps of the British Crime Survey (1982, 1984, 1988) are employed. Logistic regression is the main analytic tool used, with some interaction terms entering the set of explanatory variables. Appropriate specification tests for logit models, which are usually neglected, are conducted. The results of the tests confirm the robustness of our models. The present study addresses two questions in particular: (a) which groups of people are most threatened?; and (b) do these groups change over time and, if so, how?
Nicotinic receptor mechanisms and cognition in normal states and neuropsychiatric disorders
Authors: Sacco Kristi A. , Bannon Katie L. , George Tony P.
Published: January 2017

Cigarette smoking rates in the American population are approximately 23%, whereas rates of smoking in clinical and population studies of individuals with neuropsychiatric disorders are typically two- to four-fold higher. Studies conducted in a variety of neuropsychiatric populations [e.g. attention-deficit hyperactivity disorder (ADHD), Alzheimer's disease, schizophrenia] have collectively suggested that nicotine may be efficacious in remediating selected cognitive deficits associated with these disorders, thus providing a framework for understanding the specific vulnerability of these patients to smoking initiation and maintenance. However, the specific gain in cognitive performance produced by nicotine administration in healthy subjects with normal cognitive function is less clear. This article reviews our current understanding of central nicotinic acetylcholine receptor (nAChRs) systems in normal and neuropsychiatric disease states and, specifically, their role with respect to cognitive dysfunction and clinical symptoms in several specific neuropsychiatric populations, including ADHD, Alzheimer's disease, Parkinson's disease, Tourette's Disorder, schizophrenia and affective disorders. The potential benefits of nicotinic agents for therapeutic use in neuropsychiatric disorders is discussed, as well as directions for further research in this area.
Effect of chronic lithium treatment on glucocorticoid and 5-HT1A receptor messengerRNA in hippocampal and dorsal raphe nucleus regions of the rat brain
Authors: Mcquade Richard , Leitch Mel M. , Gartside Sarah E. , Young Allan H.
Published: January 2017

The therapeutic mechanism of action of lithium in the treatment of bipolar disorder is not well understood. Dysfunction of both 5-HT1A receptor mediated neurotransmission and the glucocorticoid receptor is associated with mood disorders, and preclinical studies suggest that lithium treatment can modulate these receptor subtypes. In this study, we investigated the effect of chronic lithium treatment on 5-HT1A receptors and glucocorticoid receptors in the rat brain. Male Sprague-Dawley rats were treated with lithium (3 mmot/kg/day) or saline for 28 days via subcutaneous implanted mini-osmotic pumps. After 28 days of treatment, the expression of mRNA for 5-HT1A receptors and glucocorticoid receptors in the rat hippocampus and dorsal raphe nucleus was determined by in situ hybridization histochemistry. Chronic administration of lithium decreased mRNA coding for post-synaptic 5-HT1A receptors in hippocampal subregions but not for somatodentritic 5-HT1A receptors in the dorsal raphe nucleus. Chronic administration of lithium did not affect mRNA coding for glucocorticoid receptors in hippocampal subregions or in the dorsal raphe nucleus. Mean plasma lithium levels in the lithium-treated group were 0.50 ± 0.03 mmol/l; all animals appeared healthy and maintained a normal increase in body weight. Given recent reports implicating hypersensitive post-synaptic 5-HT1A receptors in bipolar manic patients, the present study suggests that down-regulation of this receptor population may be important in the therapeutic mechanism of action of lithium.
P-glycoprotein is a factor in the uptake of dextromethorphan, but not of melperone, into the mouse brain: evidence for an overlap in substrate specificity between P-gp and CYP2D6
Authors: Uhr Manfred , Namendorf Christian , Grauer Markus T. , Rosenhagen Markus , Ebinger Martin
Published: January 2017

In this study, the role of P-glycoprotein (P-gp) for the pharmacokinetics of dextromethorphan, a CYP2D6 substrate, and of melperone, a CYP206 inhibitor, was investigated. The substances were administered subcutaneously near the nape of the neck of wild-type mice and of abcb1ab (–/–) mice. One hour after injection, concentrations of the two drugs in cerebrum, plasma and in different organs were measured by high-performance liquid chromatography. No significant differences between wild-type mice and abcb1ab (–/–) mice were observed for melperone, suggesting that P-gp is not involved in the uptake of melperone into the brain or other organs of mice. The concentration of dextromethorphan in the brain was more than twice as high in abcb1ab (–/–) mice compared to wild-type mice. Therefore, P-gp appears to be a factor in the uptake of dextromethorphan into the mouse brain, and abcb1-polymorphisms need to be considered for CYP2D6 phenotyping experiments with this drug. There is an overlap in substrate specificity between P-gp and CYP2D6. P-gp is a factor in the uptake of dextromethorphan, but not of melperone.
Amphetamine decreases the expression and acquisition of appetitive conditioning but increases the acquisition of anticipatory responding over a trace interval
Authors: Kantini E. , Norman C. , Cassaday H. J.
Published: January 2017

The effects of amphetamine on selective learning were tested in a trace conditioning procedure, in which the informativeness of the conditioned stimulus (CS) (noise) was manipulated through the introduction of a time interval before the delivery of the unconditioned stimulus (UCS) (food). The results showed that d-amphetamine (0.5 and 1.5 mg/kg) impaired both the expression (Experiment 1b) and acquisition (Experiment 2) of appetitive conditioning. This was true for both trace and contiguously conditioned groups. The effects of the 0.5 mg/kg dose of d-amphetamine were not attributable to general motor (measured pre-CS) or motivational (measured post-UCS) effects of the drug. Moreover, the same pattern of effects (impaired appetitive conditioning, irrespective of the trace interval between CS and UCS) was confirmed in drug-free extinction tests. By contrast to the general depression in the acquisition and expression of associative learning observed under amphetamine, the 0.5 mg/kg dose promoted the acquisition of anticipatory responses made later in the trace interval (in Experiment 2 but, again, not the expression of previous conditioning in Experiment 1b). This suggests a dissociable effect of low-dose d-amphetamine on learning about the temporal relationship between CS and UCS.
The effects of tianeptine or paroxetine on 35% CO2 provoked panic in panic disorder
Authors: Schruers Koen , Griez Eric
Published: January 2017

Antidepressants that inhibit the reuptake of serotonin (5-HT) are particularly effective in the treatment of panic disorder. Evidence suggests that increased 5-HT availability is important for the anti-panic effect of serotonergic drugs and in maintaining the response to selective serotonin reuptake inhibitors (SSRIs). Tianeptine is an antidepressant with 5-HT reuptake enhancing properties (i.e. the opposite pharmacological profile to that of SSRIs). Therefore, no effect would be expected in panic disorder. The aim of the present study was to compare the effect of tianeptine with that of paroxetine, a selective 5-HT reuptake inhibitor with demonstrated efficacy in panic disorder, on the vulnerability to a laboratory panic challenge in panic disorder patients. Twenty panic disorder patients were treated with either tianeptine or paroxetine for a period of 6 weeks, in a randomized, double-blind, separate group design. The reaction to a 35% CO2 panic challenge was assessed at baseline and after treatment. Improvement on several clinical scales was also monitored. Tianeptine, as well as paroxetine, showed a significant reduction in vulnerability to the 35% CO2 panic challenge. In spite of their opposite influence on 5-HT uptake, both tianeptine and paroxetine appeared to reduce the reaction to the panic challenge. These results raise questions about the necessity of 5-HT uptake for the therapeutic efficacy of anti-panic drugs.
The MTHFR C677T polymorphism is associated with depressive episodes in patients from Northern Ireland
Authors: Kelly Christopher B. , Mcdonnell Anne P. , Johnston Timothy G. , Mulholland Ciaran , Cooper Stephen J. , Mcmaster Dorothy , Evans Alun , Whitehead Alexander S.
Published: January 2017

Low plasma folate and its derivatives have been linked with depressive disorders in studies dating back over 30 years. A thermolabile variant (677C>T) of the enzyme 5,10-methylenetetrahydrofolate reductase (MTHFR) is associated with low serum folate. The present study aimed to explore whether the thermolabile variant of MTHFR is associated with a vulnerability to depressive episodes. MTHFR C677T genotype frequencies in a cohort of patients (mean age 48 years) with depressive disorder (n = 100) were compared with those in age- and sex-matched controls. Serum levels of folate, homocysteine and vitamin B12 were also compared between groups. The thermolabile variant of MTHFR was significantly more common in the group with a history of depressive disorder (P = 0.03). Serum levels of folate, homocysteine and vitamin B12 did not differ significantly between groups. A MTHFR C677T genotype is associated with increased risk of depressive episodes in this homogenous patient population.
Pharmacokinetic profiles contribute to the differences in behavioral pharmacology of 071031B enantiomers as novel serotonin and norepinephrine reuptake inhibitors
Authors: Xue Rui , Li Ying , He Xin-Hua , Jin Zeng-Liang , Fan Shi-Yong , Zhang Ting-Ting , Li Nuo-Min , Yuan Li , Zheng Ai-Ping , Zhong Bo-Hua , Li Yun-Feng , Zhang You-Zhi
Published: January 2017

Our previous study indicated that a chiral compound 071031B was a novel serotonin and noradrenaline reuptake inhibitor with superior antidepressant activity compared to duloxetine. The present study aimed to investigate chiral pharmacology differences of 071031B enantiomers, S-071031B and R-071031B, and disclose mechanisms underlying the behavioral differences based on target profiles and pharmacokinetic profiles. In vivo behavioral tests indicated that S-071031B was more potent than R-071031B in two depression models (the forced swimming test in mice and rats) and two pain models (the acetic acid-induced writhing and formalin tests in mice). In vitro assays revealed that both S-071031B and R-071031B showed high affinity for human serotonin transporters and norepinephrine transporters with equal potency, and showed consistently equipotent inhibitory effects on serotonin and norepinephrine uptake. Pharmacokinetic studies demonstrated that oral availability and hepatic metabolism, rather than pH stability, intestinal transport, and plasma binding, contributed to enantiomers’ behavioral differences. Based on these findings, it is suggested that S-071031B is a more active enantiomer, and the differential pharmacokinetic profiles, but not target affinity, contribute to differences of S-071031B and R-071031B in behavioral pharmacology. Moreover, current PK-PD study may provide positive exploration for chiral antidepressants development.