bluuebunny/crossref_metadata_2025_split huggingface dataset:
The disposition and effects of two doses of dichloroacetate in adults with severe falciparum malaria
Authors: KRISHNA SANJEEV , SUPANARANOND WICHAI , PUKRITTAYAKAMEE SASITHON , KUILE FEIKO TER , RUPRAH MANJIT , WHITE NICHOLAS J. 
Published: October 2008

1 Dichloroacetate (DCA) is a promising treatment for lactic acidosis complicating severe malaria. The pharmacokinetics, pharmacodynamics and toxicity of dichloroacetate were evaluated in 11 patients with severe malaria, and their lactate responses compared with nine control patients in an open–label prospective study.2 Intravenous DCA (46 mg kg‐1 infused in 30 min) or saline placebo was given on admission to the study, and 12 h later, as an adjunct to standard quinine treatment.3 An open one‐compartment model with the following parameters described the pharmacokinetics of DCA after one dose (mean [s.d.]): v = 0.44(0.2) 1 kg‐1; CL = 0.13[0.027] 1 h‐1 kg‐1; Cmax = 106[28] mg l‐1; t1/2, = 3.4(2.2)h. After two doses of DCA (n = 9) the pharmacokinetic parameters were similar to those after the first dose.4 DCA decreased venous plasma lactate concentrations by 42% of baseline values 8 h after admission, normalized arterial pH from a mean(s.d.) of 7.367(0.063) to 7.39(0.1), and decreased the calculated base deficit from 9.2(7.3) mEq 1‐1 to 6. 4(10.4) mEq 1‐1. In control patients lactate concentrations fell by ˜14% of baseline concentrations (P <0.02 compared with DCA recipients). Venous lactate concentrations fell a further 16% from baseline values after the second dose of DCA but this change was not significantly different from controls. There was no electrocardiographic or other evidence of toxicity associated with DCA.5 These data suggest that a single intravenous infusion of DCA rapidly reduces hyperlactataemia in patients severely ill with malaria, and that DCA should be evaluated further as an adjunct to conventional antimalarial and supportive measures for such patients with lactic acidosis.
Persistence of anti‐hypertensive effect after ‘missed doses' of calcium antagonist with long (amlodipine) vs short (diltiazem) elimination half‐life
Authors: LEENEN FRANS H. H. , FOURNEY ANNE , NOTMAN GAIL , TANNER JOANNA 
Published: October 2008

1 Calcium antagonists with long us short elimination half‐life may show marked differences in their antihypertensive effect during short interruptions of therapy by missed doses.2 In the present study we evaluated the blood pressure lowering effect of amlodipine us diltiazem both on active maintenance treatment and after active treatment was interrupted for 2 days by placebo using a double‐blind randomized design. After a single blind placebo run‐in period, hypertensive patients were randomized to amlodipine 5 mg once daily or diltiazem 90 mg twice daily. After 4–6 weeks, doses were increased to 10 mg once daily or 180 mg twice daily, if necessary for control of diastolic blood pressure. During week 9 or 10 on active treatment blisterpacks contained 2 days of placebo. Twenty‐four hour blood pressure monitoring was performed at the end of run‐in period and during week 9 and 10 on active us interrupted therapy.3 Active therapy by amlodipine (n = 20) lowered day systolic blood pressure by 17 ± 2 mmHg and diastolic blood pressure by 12 ± 2 mmHg and did not change heart rate. In second day of interrupted therapy most of these responses were still present. Diltiazem (n = 14) lowered day systolic blood pressure by 13 ± 2 mmHg, diastolic blood pressure by 11 ± 2 mmHg and heart rate by 10 ± 2 beats min‐1. Most of these responses had disappeared during the second day of interrupted therapy.4 We conclude that amlodipine and diltiazem are fairly similar in lowering blood pressure from an efficacy point of view. However, during short periods of non‐compliance blood pressure control will persist markedly better with the agent with a long vs the one with a short elimination half‐life.
On the cerebro‐protective effects of caroverine, a calcium‐channel blocker and antiglutamatergic drug: double‐blind, placebo‐controlled, EEG mapping and psychometric studies under hypoxia
Authors: SALETU B. , GRÜNBERGER J. , ANDERER P. , LINZMAYER L. , KÖNIG P. 
Published: October 2008

1 In a double‐blind, placebo‐controlled study, the acute antihypoxidotic properties of the calcium‐channel blocking and antiglutamatergic caroverine were investigated utilizing blood gas analysis, EEG mapping and psychometry under a transient, reversible, hypoxic hypoxidosis.2 The latter was induced by a fixed gas combination of 9.8% oxygen (02) and 90.2% nitrogen (N2) (found in 6000 m altitude), which was inhaled for 23 min under normobaric conditions by 16 healthy, young volunteers. They received randomized after an adaptation session, single oral doses of placebo, 40, 80 and 120 mg caroverine. Evaluation of blood gases, EEG mapping and psychometry were carried out 0, 2, 4, 6 and 8 h post‐drug, during hypoxia.3 Blood gas analysis demonstrated a drop in Po2 from 95 to 33 and 30 mmHg, in Pco2 from 38 to 30 and 30 mmHg in the 14th and 23rd minute of inhalation, respectively, while pH increased from 7.41 to 7.50 and 7.51. Base excess and standard bicarbonate remained stable.4 EEG mapping under hypoxia exhibited a marked increase of delta/theta, decrease of alpha and an increase of superimposed beta activity, which reflects deterioration of vigilance.5 Caroverine attenuated this hypoxia‐induced vigilance decrement in a dose‐ and time‐dependent manner 6–8 h after 80 mg and 2–8 h after 120 mg.6 Hypoxic hypoxidosis induced a deterioration of memory and attention variability, which was mitigated by 80 and 120 mg caroverine. However, there was an augmentation of the hypoxia‐induced decrement in psychomotor performance after 120 mg.7 The drug was well tolerated, and there were no significant differences compared with placebo with regard to pulse and blood pressure.
Lanreotide inhibits human jejunal secretion induced by prostaglandin El in healthy volunteers
Authors: SOBHANI IRADJ , RENÉ AKLI RAMDANI EMMANUEL , BAYOD FAYSEL , SABBAGH LUIS C. , THOMAS FRANÇOIS , MIGNON MICHEL 
Published: October 2008

1 Somatostatin inhibits hormonal secretions in the gastrointestinal tract. Somatostatin analogues are used in the treatment of VIPome‐related watery diarrhoea. In addition, more than 10% of patients with AIDS suffer from diarrhoea likely due to the increased intestinal secretion of water and ions. However, the direct effect of somatostatin on the flux of water and ions in the intestine has not been, so far, analyzed in vivo. The aim of the present study was to evaluate the effect of lanreotide, a somatostatin analogue, on the movements of water and ions in the jejunum in man.2 Accordingly, 10 healthy volunteers (age 18–35 years, mean 27) and two patients with AIDS (26 and 33 years) suffering from water diarrhoea (> 800 ml day‐1) underwent intestinal perfusion using a four lumen tube with proximal occluding balloon. The segment tested was 25 cm long. The jejunum was infused by an isotonic control saline solution containing polyethylene glycol (PEG) as non‐absorbable marker. Basal jejunal secretions were measured in all subjects. Prostaglandin El (PGE1) was administered intraluminally to stimulate jejunal secretion in healthy volunteers. The effect of intravenous lanreotide on the jejunal PGE1‐induced secretions of water and electrolytes was analysed in healthy subjects and on the basal secretions in AIDS patients. Each period was analyzed on the basis of three (10 min) successive intestinal juice collections after 20–30 min equilibration time. The antisecretory effect of lanreotide was evaluated in each subject as the difference between fluxes compared to the control period.3 In healthy volunteers, PGE1 induced secretion of H2O, Na+, K+ and C1‐ in the jejunum and lanreotide reduced significantly PGE1‐induced response. In both AIDS patients basal fluxes of water and ions were reduced by lanreotide in a dose‐dependent manner.4 Somatostatin can reduce stimulated‐jejunal secretion of ions and water in normal subjects and may improve water diarrhoea in AIDS patients.
Bearing tests of prestress wire on various steels
Authors: SIDWELL E. H. , RAJNARINE R. R. 
Published: October 2008

An account is given of an experimental investigation to find a steel suitable for bearing pressures from 70 to 100 tonf/in2 (1 081 to 1544 MN/m2) in order to use it for the anchorages of an energised (prestressed) beam. This beam and other structural elements employ a new concept involving compressed wires reacting on the anchorages thus producing high bearing stresses.Various groupings of 0–276 in (7 mm) diameter wires are employed. It is shown that mild steel is unsuitable for such an anchorage.
Some factors affecting long‐term stability of strain measurements using metal foil gauges
Authors: POPLE J. 
Published: October 2008

The stability of long‐term strain measurements is very much dependent on the correct selection of techniques, materials and equipment for the conditions under which the measurements are to be taken.Temperature effects are also a major factor. Temperature‐induced changes in resistance of the Wheat‐stone bridge completion and balancing components can result in an output signal indistinguishable from that produced by change of gauge resistance due to surface strain. The signal conditioning and readout equipment can also be affected by temperature and become an additional source of instability.The term ‘instability’, in strain gauging, generally refers to ‘zero drift’ and random deviations of readings when the loading conditions are stationary. In particular it refers to those situations where a measurement system has been balanced and measurements have been taken with a particular load condition which cannot be repeated to re‐check the original zero.In this paper the major sources of instability are identified and recommendations are made as to how best to obtain long‐term stability of strain measurements using metal foil gauges.Information on principal error sources in strain measurement systems using metal foil gauges is included for completeness and because an appreciation of these sources is also vitally important.
A transducer for determining dynamic drag and lift coefficients in wind tunnels
Authors: Kanda J. , Royles R. 
Published: October 2008

A transducer is described capable of determining dynamic drag and lift coefficient for bluff bodies in air flow. Such factors and their frequency dependence are becoming increasingly important in the wind excitation of structures.The device incorporates facilities for varying the angle of attack on the model structure surface and although developed for studies on bluff bodies it can be adapted readily to other bodies of uniform section including aerofoil, circular cylindrical, and more general shapes.Dynamic output is derived from electric foil strain gauges and circuitry yielding measurements of good linearity, repeatability and stability.
Interactive control for an automatic polariscope
Authors: ALLISON I. M. , NURSE P. 
Published: October 2008

The problems of interpreting and analysing photo‐elastic data have deterred non‐specialists from making use of this technique when undertaking detailed design studies. Practical difficulties in understanding complex fringe patterns and in making the necessary optical measurements with sufficient precision have implied that considerable experience is necessary to obtain reliable stress values at internal points or across critical sections.By interconnecting two minicomputers it has been possible to develop an interactive polariscope control system which will allow the design engineer, with minimal prior knowledge of photoelastic techniques, to employ relatively sophisticated methods for evaluating the stresses in both two and three dimensional models. The data acquisition sequence involves new procedures for determining both the isoclinic angle and the isochromatic fringe number, and the interactive nature of the control system allows the desired analysis to proceed in response to the replies to a series of simple questions posed by the machine.The application of the system will be illustrated by examples of its use to determine boundary stresses at critical locations, where the high stress gradient presents problems, and in evaluating the separate stress components across the critical section of a grooved cylindrical rod.
The role of the British Society for Strain Measurement and in particular the Product Quality and Reliability Testing Group in enhancement of the Nation's quality and reliability initiative*
Authors: Chalmers G. F. 
Published: October 2008

This paper reviews the very important role of the BSSM in contributing to the wide understanding and application of experimental stress analysis in product design evaluation and testing.The paper presents the benefits of strain measurement techniques and a number of initiatives which have been taken by the BSSM in relation to quality and reliability which have included meetings held in conjunction with other organisations, the BSSM Certificate Scheme and involvement in standards for strain gauge measurements.The paper concludes with some facts and figures related to Quality Assurance, and costs of failure and fracture, from authoritative published sources in the UK and USA.
Telemetry applied to strain gauging
Authors: Phillips K. J. 
Published: October 2008

An insight into strain gauge telemetry techniques explaining why telemetry can offer interesting advantages over conventional strain gauge systems. The difference between a.c. strain gauge measurements and analogue to digital conversion followed by a.c. transmission is discussed together with the importance of a.c. transmission in the avoidance of drifts and parasitic effects applicable to d.c. systems.A comparison between frequency modulation (FM) and time or pulse duration modulation (PDM) explains why PDM can offer significant advantages.
Engineering metrology—a measure of progress
Authors: Poulter K. F. 
Published: October 2008

In 1952 Mr F. H. Rolt, one of the pioneers of engineering metrology, who had worked at NPL for over 40 years reviewed the progress in this area during the first half of the 20th century. He concluded his lecture by identifying eight topics on which progress could be expected.This paper considers each of these areas and identifies where progress has occurred. The paper concludes with a few new predictions for the next decade or so.
Comparison of techniques for residual stress determination in a bead on plate titanium sample
Authors: Brown D. K. , Owens A. 
Published: October 2008

Residual stress determination has been carried out on production welds to provide engineering data.A parting out technique has been used in which a strain gauged through thickness slug of material is removed from the weld area.The centre hole technique has been used with the blind hole in the weld material.There were differences between the results from the two techniques and a fully penetrant bead on plate fatigue sample with the bead running axially was used in order to compare the two techniques in more detail.After parting out, the layer removal technique was carried out in order to provide a relatively detailed through thickness residual stress distribution in order to explain the differences between the results from the centre hole and parting out techniques.
The measurement of the distribution of residual stresses through the thickness of a welded joint
Authors: Ritchie D. , Leggatt R. H. 
Published: October 2008

A new method for the measurement of residual stresses in welded joints of complex cross section is described. The method involves the measurement of strain changes in the body as a narrow slot is cut in the plane of interest, in small increments of depth. A finite element model of the cross section is used to relate the strain changes at the measurement points to the residual stresses across the slot plane.The accuracy of the method is demonstrated by using it to measure a known residual stress field in a cold bent bar. The method has been used in combination with a block removal technique to measure the through wall distribution of axial residual stresses at a circumferential butt weld in a cylinder with a protruding root bead. It could also be applied to the measurement of residual stresses in other joint configurations, such as fillet welds or T‐butt welds.
Strain distribution along lapped joints in reinforced concrete
Authors: Judge R. C. B. , Scott R. H. , Gill P. A. T. 
Published: October 2008

Strain measurements along lapped joints in reinforced concrete tension members were obtained using a method of internally strain gauging the reinforcing rods. Strain concentration gauges, installed at the lap ends of some specimens, demonstrated the localised nature of force transfer prior to crack formation.Results from ten test specimens of varying lap length and rod diameter have been produced. The changes observed in the longitudinal strain distributions, and the associated bond and concrete stresses as cracks developed are presented.
An alternative determination of unmodified temperature T1 for eliminating thermal strain during load testing of engineering structures
Authors: Hsiang‐Te Tu 
Published: October 2008

A method of determining the unmodified temperature, T1, for elimination of thermal strain from the load testing is presented. It is based on the fact that the intersection point of two T–ε lines for a test point shows zero stress (or strain) and coincides with the known zero stress at the neutral axis of the structure, if the test point is set at the axis. The abscissa of this intersection point indicates the unmodified temperature T1. The method has been applied to the load test on a suspect beam in a 4‐storey building. The conclusion was reached that although the suspect beam was weaker than normal, it could take the assigned load without any remedial measures. This conclusion was verified by the practical evidence of normal service for more than five years.The method is applicable to certain types of structures at the moment.
The flexural fatigue performance of plain and fibrous concretes
Authors: Butler J E 
Published: October 2008

If fatigue cracking is going to occur in concrete structures then it is more likely due to repeated flexural loadings rather than direct compression or tension. Typical examples are road and airfield pavements, bridges, offshore constructions and structures likely to experience earthquakes. Also many of these loadings have a dynamic character and a knowledge of material behaviour at rapid stressing rates as an essential preliminary requirement to understanding flexural fatigue performance. Therefore since flexural loadings are frequently encountered in practical situations then the flexural test is probably one of the most useful types to be used in the examination of both the fatigue behaviour of concrete and its ultimate strength developed at rapid loading rates.Although the designer regards concrete as an homogeneous material, it consists of two phases, the active hardened cement phase, which is the binding material to the inert phase, the aggregate. Concrete behaviour can therefore be complex and aspects interpreted at either the macroscopic, microscopic or molecular level. The composite nature of concrete may be further complicated by the introduction of steel reinforcement. Over the last few years there has been a general research interest with the incorporation of small quantities of fibres in concrete. Steel fibres of dimensions 10mm to 60mm in length, 10m to 60 m in diameter, with material properties ranging from 150 GN/m 2 to 200 GN/m 2 in elastic modulus and 700 N/mm2 to 200 N/mm2 in tensile strength may be introduced at the mixing stage in proportions between 0.5% and 3.5% of concrete volume. The consequent enhancement in flexural strength is substantial and the likelihood of a similar improvement in fatigue performance needed to be demonstrated.It has also been common practice when conducting modulus of rupture tests, to use 500mm × 100mm × 100mm specimens for mixes incorporating fibres. When casting such specimens there is a danger of fibres not being randomly orientated. Thus for this investigation, beams of 1500 times 200 times 200mm have been used. The selection of larger beams also makes instrumentation more manageable and the dimensions may be more comparable with those associated with most practical applications.Some fifty fatigue tests have been completed supported by a further five hundred strength and control tests. A complete series of strain, deflection and crack development histories have been observed. An appropriate form of S‐N curve has been adapted for the examination of results. Models explaining the behaviour of both plain and fibrous concretes have been proposed and a method of flexural fatigue performance prediction has been formulated.
Measurement of dynamic response and failure of pipework
Authors: Beaney E M 
Published: October 2008

Pipework in nuclear power stations is designed to withstand the effects of earthquakes. The current methods of design are known to be very conservative and lead to the inclusion of large numbers of pipework restraints. These restraints are only included to limit stresses in the unlikely event of an earthquake but they can, under some circumstances, increase stresses during comparatively frequent thermal transients and thus their unnecessary inclusion is undesirable.With the ultimate objective of reducing aseismic design conservatism the experimental work, described in this paper, has been conducted at Berkeley Nuclear Laboratories (BNL) to investigate the response and failure of pipework under high levels of dynamic excitation. The initial work was aimed at response prediction, but it is now clear that the improvement of failure criteria is a preferred route to reduce design conservatism. The measurement of high strains and dynamic yield performance of materials has necessitated the development of novel measurement techniques which have wider application in other areas. This experimental work is now finished, and the results are being used to support a change in the design codes.
The role and benefits of testing in product quality management
Authors: Pomeroy R. V. 
Published: October 2008

AbstractA key requirement for most engineered items is the ability to withstand the various loads that may be applied under conditions of use and of abuse that may reasonably be foreseen. To ensure that the strength requirement is satisfied, the designer must evaluate the levels of applied stress using appropriate calculation methods or by physical experiment. This paper considers the respective roles of computational and experimental methods of stress analysis, discussing the impact of changes in functional capability. Reference is made to the modern certification environment and the requirements of quality assurance, particularly related to the training of engineers and technicians in the necessary skills.The paper aims to present a balanced view of the role of experimental stress analysis, identifying areas where there are clear benefits. Some concluding comments are made regarding education, training and vocational qualifications.