bluuebunny/crossref_metadata_2025 huggingface dataset:
Anomalous nonlinear dielectric and Kerr effect relaxation steady state responses in superimposed ac and dc electric fields
Authors: Coffey William T. , Kalmykov Yuri P. , Titov Sergey V.
Published: February 2007

It is shown how the rotational diffusion model of polar molecules (which may be described in microscopic fashion as the diffusion limit of a discrete time random walk on the surface of the unit sphere) may be extended to anomalous nonlinear dielectric relaxation and the dynamic Kerr effect by using a fractional kinetic equation. This fractional kinetic equation (obtained via a generalization of the noninertial kinetic equation of conventional rotational diffusion to fractional kinetics to include anomalous relaxation) is solved using matrix continued fractions yielding the complex nonlinear dielectric susceptibility and the Kerr function of an assembly of rigid dipolar particles acted on by external superimposed dc E0 and ac E1(t)=E1cosωt electric fields of arbitrary strengths. In the weak field limit, analytic equations for nonlinear response functions are also derived.
Cirrus cloud mimics in the laboratory: An infrared spectroscopy study of thin films of mixed ice of water with organic acids and ammonia
Authors: Hellebust Stig , O’Riordan Brian , Sodeau John
Published: February 2007

The structures of formic and acetic acids deposited on a thin gold substrate held in vacuum at low temperatures and their related water-ice promoted chemistry have been investigated. The condensed water/guest films were taken to act as cirrus cloud “mimics.” Such laboratory representations provide a necessary prelude to understanding how low temperature surfaces can affect chemical composition changes in the upper atmosphere. The systems were characterized by reflection-absorption infrared spectroscopy and temperature-programed desorption spectrometry. The interaction behavior of the binary acid ices was compared to that observed when ternary mixtures of water, formic acid, and ammonia were deposited. Differences in the chemistry were observed depending on deposition method: layering or mixing. The more atmospherically relevant codeposition approach showed that at low temperatures, amorphous formic acid can be ionized to its monodentate form by water ice within the bulk rather than on the surface. In contrast, the introduction of ammonia leads to full bidentate ionization on the ice surface. The thermal desorption profiles of codeposited films of water, ammonia, and formic acid indicate that desorption occurs in three stages. The first is a slow release of ammonia between 120 and 160K, then the main water desorption event occurs with a maximum rate close to 180K, followed by a final release of ammonia and formic acid at about 230K originating from nonhydrous ammonium formate on the surface. The behavior of acetic acid is similar to formic acid but shows lesser propensity to ionize in bulk water ice.
Adsorption and dissociation of hydrogen on Li3N surface: A first principles study
Authors: Jin H. M. , Luo J. Z. , Wu P.
Published: February 2007

The adsorption and dissociation of hydrogen on Li3N surface are studied by density functional theory calculations and experiment. The surface energies of four low index surfaces (001), (010), (100), and (010) are calculated. Results show that (001) has the lowest surface energy of 1.28J∕m2 compared to other three surfaces; therefore, (001) surface is selected for H2 adsorption and dissociation study. For H2 molecule adsorption, results show that the most stable adsorption site is on the N top with adsorption energy of 0.14eV. For the dissociated hydrogen atoms, the most stable adsorption site is on two N tops, with adsorption energy of 5.12eV per H atom. The calculated energy barrier for H2 dissociation is about 0.79eV, which is smaller than that of experimental value of 1.22eV.
Spatial charge cloud size of microchannel plates
Authors: Saito M. , Saito Y. , Asamura K. , Mukai T.
Published: February 2007

We examine the spatial evolution of charge clouds emitted by microchannel plates (MCPs). A model of this evolution is presented, along with a comparison to experimental results. We also present an experimental method to measure the charge cloud radius in which the radial charge cloud distribution is assumed to be Gaussian. When a charge cloud is released from the MCP, its initial size is determined by the number and distribution of excited channels. The size of the charge cloud is examined as a function acceleration voltage, distance between MCP and anode, and MCP bias voltage. Since electrons released from the MCP have various initial energies and angular divergence, the charge cloud size increases as it travels away from the MCP. Space charge effects also contribute to the growth of the charge cloud. The experimental results are in close agreement with our model, which includes these effects. From experiment, we also derive an approximate expression for charge cloud radius as a function of acceleration voltage and distance between MCP and anode. This expression can be used for the practical design and optimization of a position sensing system comprised of multiple anodes.
Active cancellation of stray magnetic fields in a Bose-Einstein condensation experiment
Authors: Dedman C. J. , Dall R. G. , Byron L. J. , Truscott A. G.
Published: February 2007

A method of active field cancellation is described, which greatly reduces the stray magnetic field within the trap region of a Bose-Einstein condensation experiment. An array of six single-axis magnetic sensors is used to interpolate the field at the trap center, thus avoiding the impractical requirement of placing the sensor within the trap. The system actively suppresses all frequencies from dc to approximately 3000 Hz, and the performance is superior to conventional active Helmholtz cancellation systems. A method of reducing the field gradient, by driving the six Helmholtz coils independently, is also investigated.
Use of Si+ pre-ion-implantation on Si substrate to enhance the strain relaxation of the GexSi1−x metamorphic buffer layer for the growth of Ge layer on Si substrate
Authors: Hsieh Y. C. , Chang E. Y. , Luo G. L. , Pilkuhn M. H. , Tang S. S. , Chang C. Y. , Yang J. Y. , Chung H. W.
Published: February 2007

Si + pre-ion-implantation combined with a GexSi1−x metamorphic buffer structure for the growth of Ge layer on Si substrate is proposed. Enhanced strain relaxation of the GexSi1−x metamorphic buffer layer on Si substrate was achieved due to the introduction of the point defects by heavy dose Si+ pre-ion-implantation. Because of the strain relaxation enhancement and the interface blocking of the dislocations in the GexSi1−x metamorphic buffer structure, the total thickness of the buffer layers was only 0.45μm. No cross-hatch pattern was observed on the Ge surface and the dislocation density for the top Ge film was only 7.6×106cm−2.
Dissociative scattering of hyperthermal energy CF3+ ions from modified surfaces
Authors: Rezayat Talayeh , Shukla Anil
Published: February 2007

Dissociative scattering of CF3+ ions in collision with a self-assembled monolayer surface of fluorinated alkyl thiol on a gold 111 crystal has been studied at low ion kinetic energies (from 29to159eV) using a custom built tandem mass spectrometer with a rotatable second stage energy analyzer and mass spectrometer detectors. Energy and intensity distributions of the scattered fragment ions were measured as a function of the fragment ion mass and scattering angle. Inelastically scattered CF3+ ions were not observed even at the lowest energy studied here. All fragment ions, CF2+, CF+, F+, and C+, were observed at all energies studied with the relative intensity of the highest energy pathway, C+, increasing and that of the lowest energy pathway, CF2+, decreasing with collision energy. Also, the dissociation efficiency of CF3+ decreased significantly as the collision energy was increased to 159eV. Energy distributions of all fragment ions from the alkyl thiol surface showed two distinct components, one corresponding to the loss of nearly all of the kinetic energy and scattered over a broad angular range while the other corresponding to smaller kinetic energy losses and scattered closer to the surface parallel. The latter process is due to delayed dissociation of collisionally excited ions after they have passed the collision region as excited parent ions. A similar study performed at 74eV using a LiF coated surface on a titanium substrate resulted only in one process for all fragment ions; corresponding to the delayed dissociation process. The intensity maxima for these fragmentation processes were shifted farther away from the surface parallel compared to the thiol surface. A new mechanism is proposed for the delayed dissociation process as proceeding via projectile ions’ neutralization to long-lived highly excited Rydberg state(s), reionization by the potential field between the collision region and entrance to the energy analyzer, and subsequent dissociation several microseconds after collisional excitation. A kinematic analysis of experimental data plotted as velocity Newton diagrams demonstrates that the delayed dissociation process results from the collisions of the ion with the bulk surface; i.e., the self-assembled monolayer surface acts as a bulk surface. A similar analysis for the highly inelastic collision processes shows that these are due to stronger collisions with a fraction of the thiol molecular chain, varying in length (mass) with the ion energy.
A model of CaF2 indentation
Authors: Zhang Q. , Lambropoulos J. C.
Published: February 2007

A finite element model (FEM) of calcium fluoride (CaF2) with a rate-dependent mesoplastic constitutive formulation was developed and compared with nanoindentation tests. Indentations on the three main crystallographic planes (100), (110), and (111) of (CaF2) were analyzed. Appropriate material parameters were obtained by correlating the FEM results and the corresponding experimental load-displacement curves. The simulations show a value in the range of 74–110MPa for the initial shear yield strength and a value in the range of 100–180MPa for the self-hardening modulus. Such estimates can be used to examine the detailed stress distribution induced by the indentation.
On the accurate determination of thermal diffusivity of liquids by using the photopyroelectric thickness scanning method
Authors: Delenclos S. , Dadarlat D. , Houriez N. , Longuemart S. , Kolinsky C. , Hadj Sahraoui A.
Published: February 2007

An enhanced accurate method of measuring the thermal diffusivity of liquids by the sample’s thickness scan of the phase of the photopyroelectric signal is presented. The method, making use of the absolute values of the phase and sample thickness, leads to very accurate results for the room temperature values of thermal diffusivity (about ±0.3%). The high accuracy of the method is due to a very precise control of the sample’s thickness variation (0.1μm step), to a proper localization of the thickness scan range, and to a new procedure of data analysis. The high accuracy of the method recommends it for the study of processes associated with small changes of the thermal parameters.
Dielectric and piezoelectric properties of lead-free 0.95(K0.5Na0.5)NbO3–0.05LiNbO3 crystals grown by the Bridgman method
Authors: Chen Kai , Xu Guisheng , Yang Danfeng , Wang Xiaofeng , Li Junbao
Published: February 2007

Lead-free potassium sodium niobate piezoelectric single crystals substituted with lithium 0.95(K0.5Na0.5)NbO3–0.05LiNbO3 have been grown by Bridgman method and their dielectric and piezoelectric properties were studied. The orthorhombic-tetragonal and tetragonal-cubic phase transition temperatures of the single crystal appear at 192 and 426°C according to the dielectric constant versus temperature loops, respectively, and the (001) plates show good piezoelectric properties with piezoelectric constant d33 as high as 405pC∕N, large thickness electromechanical coupling factor kt=61%, and low dielectric constant of 185 at room temperature. These excellent properties show that the 0.95(K0.5Na0.5)NbO3–0.05LiNbO3 single crystal is a good lead-free piezoelectric material.
Enhanced field emission properties from well-aligned zinc oxide nanoneedles grown on the Au∕Ti∕n-Si substrate
Authors: Park Chan Jun , Choi Duck-Kyun , Yoo Jinkyoung , Yi Gyu-Chul , Lee Cheol Jin
Published: February 2007

The authors investigated the field emission from vertically well-aligned zinc oxide (ZnO) nanoneedles grown on the Au∕Ti∕n-Si (100) substrate using metal organic chemical vapor deposition. The turn-on field of ZnO nanoneedles was about 0.85V∕μm at the current density of 0.1μA∕cm2, and the emission current density of 1mA∕cm2 was achieved at the applied electric field of 5.0V∕μm. The low turn-on field of the ZnO nanoneedles was attributed to very sharp tip morphology, and the high emission current density was mainly caused by the formation of the stable Ohmic contact between the ZnO nanoneedles and Au film.
One-step electrospun nanofiber-based composite ropes
Authors: Liu Lu-Qi , Eder Michaela , Burgert Ingo , Tasis Dimitrios , Prato Maurizio , Daniel Wagner H.
Published: February 2007

A one-step procedure to assemble nanoscale electrospun poly(methylmetacrylate) (PMMA) and multiwall carbon nanotube (MWCNT) reinforced PMMA fibers into twisted continuous ropes is presented. A post-treatment procedure following rope assembly is essential to maximize the mechanical properties of the ropes. A comparison between the mechanical properties of the individual nanoscale fibers and microscale ropes reveals that rope strength variability is advantageously smaller than single fiber strength variability, but also that the average rope strength is smaller than the single fiber strength. The incorporation of MWCNTs in PMMA ropes often leads to a significant increase in failure strain and toughness.
Magnetoelectric resonance behavior of simple bilayered Pb(Zr,Ti)O3–(Tb,Dy)Fe2∕epoxy composites
Authors: Shi Zhan , Ma Jing , Lin Yuanhua , Nan Ce-Wen
Published: February 2007

Magnetoelectric resonance behavior of a simple, bilayered structure of Pb(Zr,Ti)O3 ceramic chip and (Tb,Dy)Fe2∕epoxy mixture layer is investigated. Our results show that there occur three kinds of resonance, which are attributed to the first-order flexural, second-order flexural, and radial resonance modes, respectively. The measured phase spectra show a significant phase change around each resonance frequency. The thinner PZT chip is benefit for higher flexural resonance magnetoelectric effect. The magnetoelectric effects measured under open and short electric boundary conditions show different behaviors. This simple bilayered structure exhibits a large charge output of about 300pC∕Oe at the resonance frequency.
Improvement of the electrical and ferromagnetic properties in La0.67Ca0.33MnO3 thin film irradiated by CO2 laser
Authors: Chang Lei , Jiang Yijian , Ji Lingfei
Published: February 2007

The authors report significant improvement in the electrical and magnetic properties of La0.67Ca0.33MnO3 thin film irradiated by CO2 laser in air for several dozens of seconds. It is shown that after CO2 laser irradiation the crystallinity of the film is strongly enhanced, and the surface structure is remarkably modified and displays a plainlike morphology with a lower surface roughness. The authors find that CO2 laser irradiation results in a sharp decrease in the resistivity and a notable increase in the temperature coefficient of resistance, the insulator-metal transition temperature, and ferromagnetic transition temperature. The experimental results suggest that CO2 laser irradiation is a fast and effective method to optimize colossal magnetoresistance materials for technological applications.
Surface modification of MgAl2O4 (111) for growth of high-quality ZnO epitaxial films
Authors: Zeng Z. Q. , Liu Y. Z. , Yuan H. T. , Mei Z. X. , Du X. L. , Jia J. F. , Xue Q. K. , Zhang Z.
Published: February 2007

A magnesium wetting layer was used to modify the surface structure of MgAl2O4 (111) substrate to achieve growth of high-quality ZnO film by radio frequency plasma-assisted molecular beam epitaxy. It is found that this magnesium layer plays a crucial role in 30° rotation domain elimination, defect density reduction, and polarity control of ZnO film, as demonstrated by in situ reflection high-energy electron diffraction and ex situ transmission electron microscopy. Atomic force microscopy observation shows smooth ZnO surfaces with clearly resolved atomic steps of the films.
Frequency upconversion in Er3+ doped PbO–GeO2 glasses containing metallic nanoparticles
Authors: da Silva Davinson Mariano , Kassab Luciana Reyes Pires , Lüthi Stefan R. , de Araújo Cid B. , Gomes Anderson S. L. , Bell Maria José Valenzuella
Published: February 2007

The authors report the infrared-to-visible frequency upconversion (UPC) process in Er3+ doped PbO–GeO2 glasses containing silver nanoparticles (NPs) with an average diameter of 2.2nm. The absorption spectra of the samples present a band centered at 470nm due to the surface plasmons associated with the NPs. The intensity of the band grows with increasing NP concentration. The experiments were performed by exciting the samples with a 980nm diode laser and observing the UPC emissions in the red-green region. The enhanced UPC intensity is attributed to the local field effect in the proximity of the NPs.
Orientation and temperature dependence of domain wall properties in FePt
Authors: Hinzke D. , Nowak U. , Chantrell R. W. , Mryasov O. N.
Published: February 2007

An investigation of the orientation and temperature dependence of domain wall properties in FePt is presented. The authors use a microscopic, atomic model for the magnetic interactions within an effective, classical spin Hamiltonian constructed on the basis of spin-density functional calculations. They find a significant dependence of the domain wall width as well as the domain wall energy on the orientation of the wall with respect to the crystal lattice. Investigating the temperature dependence, they demonstrate the existence of elliptical domain walls in FePt at room temperature. The consequences of their findings for a micromagnetic continuum theory are discussed.
A Theory of Institutional Change: Illustrated by Dutch City-Provinces and Dutch Land Policy
Authors: Buitelaar Edwin , Lagendijk Arnoud , Jacobs Wouter
Published: February 2007

Since the early 1990s, planning theory has focused on the issue of institutional change. Not only does institutional change have clear bearings on processes of spatial planning, it is also, increasingly, seen as an object of planning. A core concept in the literature is the juxtaposition of ‘institutional design’ and ‘institutional evolution’. Yet, in understanding processes and the role of institutional change, this dichotomy does not appear to be very helpful. We therefore propose a more encompassing perspective that includes both ‘design’ and ‘evolution’ dimensions, invoking various components from theories of policy change, inspired by the work of Kingdon. We try to unravel, in particular, why, under seemingly comparable conditions, some cases show substantive institutional transformations while others do not. We briefly discuss two cases from the Netherlands to illustrate this point, namely the thwarted process of establishing city regions within the scalar fabric of territorial governance, and some instrumental changes in land policy.
Association of a common complement receptor 2 haplotype with increased risk of systemic lupus erythematosus
Authors: Wu Hui , Boackle Susan A. , Hanvivadhanakul Punchong , Ulgiati Daniela , Grossman Jennifer M. , Lee Youngho , Shen Nan , Abraham Lawrence J. , Mercer Timothy R. , Park Elly , Hebert Lee A. , Rovin Brad H. , Birmingham Dan J. , Chang Deh-Ming , Chen Chung Jen , McCurdy Deborah , Badsha Humeira M. , Thong Bernard Y. H. , Chng Hiok H. , Arnett Frank C. , Wallace Daniel J. , Yu C. Yung , Hahn Bevra H. , Cantor Rita M. , Tsao Betty P.
Published: February 2007

A genomic region on distal mouse chromosome 1 and its syntenic human counterpart 1q23–42 show strong evidence of harboring lupus susceptibility genes. We found evidence of linkage at 1q32.2 in a targeted genome scan of 1q21–43 in 126 lupus multiplex families containing 151 affected sibpairs (nonparametric linkage score 2.52,P= 0.006). A positional candidate gene at 1q32.2, complement receptor 2 (CR2), is also a candidate in the murineSle1clupus susceptibility locus. To explore its role in human disease, we analyzed 1,416 individuals from 258 Caucasian and 142 Chinese lupus simplex families and demonstrated that a common three-single-nucleotide polymorphismCR2haplotype (rs3813946, rs1048971, rs17615) was associated with lupus susceptibility (P= 0.00001) with a 1.54-fold increased risk for the development of disease. Single-nucleotide polymorphism 1 (rs3813946), located in the 5′ untranslated region of theCR2gene, altered transcriptional activity, suggesting a potential mechanism by which CR2 could contribute to the development of lupus. Our findings reveal thatCR2is a likely susceptibility gene for human lupus at 1q32.2, extending previous studies suggesting that CR2 participates in the pathogenesis of systemic lupus erythematosus.
Effect of carbonates/phosphates as nucleophilic catalysts in dimethylformamide for efficient cyanosilylation of aldehydes and ketones
Authors: Prakash G. K. Surya , Vaghoo Habiba , Panja Chiradeep , Surampudi Vijayalakshmi , Kultyshev Roman , Mathew Thomas , Olah George A.
Published: February 2007

Cyanosilylation of aldehydes and aliphatic ketones can be carried out in dimethylformamide even without the use of any catalyst. In the presence of nucleophilic catalysts such as carbonate and phosphate salts, the reaction rate is significantly enhanced.
Whole-genome ChIP–chip analysis of Dorsal, Twist, and Snail suggests integration of diverse patterning processes in the Drosophila embryo
Authors: Zeitlinger Julia , Zinzen Robert P. , Stark Alexander , Kellis Manolis , Zhang Hailan , Young Richard A. , Levine Michael
Published: February 2007

Genetic studies have identified numerous sequence-specific transcription factors that control development, yet little is known about their in vivo distribution across animal genomes. We determined the genome-wide occupancy of the dorsoventral (DV) determinants Dorsal, Twist, and Snail in the Drosophila embryo using chromatin immunoprecipitation coupled with microarray analysis (ChIP–chip). The in vivo binding of these proteins correlate tightly with the limits of known enhancers. Our analysis predicts substantially more target genes than previous estimates, and includes Dpp signaling components and anteroposterior (AP) segmentation determinants. Thus, the ChIP–chip data uncover a much larger than expected regulatory network, which integrates diverse patterning processes during development.
Role of SVP in the control of flowering time by ambient temperature in Arabidopsis
Authors: Lee Jeong Hwan , Yoo Seong Jeon , Park Soo Hyun , Hwang Ildoo , Lee Jong Seob , Ahn Ji Hoon
Published: February 2007

Plants must perceive and rapidly respond to changes in ambient temperature for their successful reproduction. Here we demonstrate that Arabidopsis SHORT VEGETATIVE PHASE (SVP) plays an important role in the response of plants to ambient temperature changes. The loss of SVP function elicited insensitivity to ambient temperature changes. SVP mediates the temperature-dependent functions of FCA and FVE within the thermosensory pathway. SVP controls flowering time by negatively regulating the expression of a floral integrator, FLOWERING LOCUS T (FT), via direct binding to the CArG motifs in the FT sequence. We propose that this is one of the molecular mechanisms that modulate flowering time under fluctuating temperature conditions.
Functional interactions between the Moses corepressor and DHR78 nuclear receptor regulate growth in Drosophila
Authors: Baker Keith D. , Beckstead Robert B. , Mangelsdorf David J. , Thummel Carl S.
Published: February 2007

Expression of the Drosophila orphan nuclear receptor DHR78 is regulated by the steroid hormone ecdysone and is required for growth and viability during larval stages. In contrast to our understanding of its biological functions, however, relatively little is known about how DHR78 acts as a transcription factor. Here we show that DHR78 is an obligate partner for Moses (Middleman of seventy-eight signaling), a SAM (sterile α motif) domain-containing cofactor that requires DHR78 for its stability. Unlike other nuclear receptor cofactors, Moses has no obvious interaction domains and displays a unique binding specificity for DHR78. Moses acts as a corepressor, inhibiting DHR78 transcriptional activity independently of histone deacetylation. Consistent with their close association, DHR78 and Moses proteins are coexpressed during development and colocalize to specific genomic targets in chromatin. Moses mutants progress normally through early larval stages, like DHR78 mutants, but display an opposite overgrowth phenotype, with hypertrophy of adult tissues. Genetic interactions between DHR78 and moses result in a similar phenotype, suggesting that the relative dose of Moses and DHR78 regulates growth and prevents cancer. The tight functional association between DHR78 and Moses provides a new paradigm for understanding the molecular mechanisms by which cofactors modulate nuclear receptor signaling pathways.
Twenty years ago
Authors: MACINTOSH R. R.
Published: February 2007

Comments on the article ARTIFICIAL RESPIRATION by E. A. Pask

Anaesthesia (1948) 3, 58
Fatal anaphylactic reaction to tetracycline in the postoperative period
Authors: SINGH C. V. , GROVER V. , KAMRA G. L.
Published: February 2007

A case of anaphylactic reaction in the form of acute cyanosis, hypotension with sudden and unexpected death of a patient in the postoperative period following the administration of tetracycline is described. There was no history of previous exposure to the drug.
Topography of the lumbar epidural space
Authors: HUSEMEYER R.P. , WHITE D.C.
Published: February 2007

Polyester resin was injected into the epidural space of fresh adult cadavers to study the shape of the lumbar epidural space and the spatial relationship between the dura mater and vertebral canal. In most of the anatomical preparations the shape of the lumbar dural sac was distinctly triangular and in some cases a dorso‐median fold of the dura was apparent. These observations support the explanation suggested by others to account for the midline translucency seen in contrast radiological examination of the lumbar epidural space. Factors which may influence the shape and dimensions of the lumbar epidural space are discussed. It is suggested that these anatomical observations may have clinical significance in the practice of lumbar epidural analgesia.
Complement activation during cardiopulmonary bypass
Authors: HASLAM P.L. , TOWNSEND P.J. , BRANTHWAITE M.A.
Published: February 2007

Conversion of C3, the third component of complement, has been studied using a two‐dimensional immunoelectrophoretic method. Evidence of C3 conversion has been obtained in stored donor blood, in patients during and after cardiac surgery involving cardiopulmonary bypass, and occasionally during thoractomy for pulmonary resection. It is suggested that complement activation is one factor contributing to tissue injury after cardiopulmonary bypass.
Lorazepam as night sedation and premedication: a comparison with diazepam
Authors: Studd C. , Eltringham R. J.
Published: February 2007

Fifty healthy female patients scheduled for surgery were randomly allocated into two groups in a double‐blind study. One group received lorazepam 2·5 mg orally at 2200 h on the evening before surgery as night sedation, and again at 0800 h on the morning before surgery as premedication. The second group received diazepam 10 mg orally at the same times.

The quality of sleep the right before surgery was superior in the lorazepam group (p <0 02). The frequency of effective sedation produced pre‐operatively was similar in both groups. Although the incidence of amnesia for Visual stimuli following lorazepam was higher (p < 0·05) than with diazepam, there was no difference in the recall of auditory and painful stimuli. The overall incidence of side effects was similar for each drug and at the dosage used no difference was found in the time to awaken from anaesthesia.
Solar‐powered ventilator alarm
Authors: BARNETT T.G. , KOEZE T.H.
Published: February 2007

A ventilator alarm device is described with some unique features.

It has a very low current consumption. This allows prolonged operation from small batteries which may be recharged from the ambient light in the room.

The device is automatically activated and de‐activated by the pressure wave from the ventilator. No external switches or other controls are necessary.

The very small size means that the device can be directly attached to a ventilator ‘in line’ with the ventilator circuit. There are no tubing connexions between the ventilator and the alarm device and no separate shelf‐space is required.
Rebound hypertension during anaesthesia
Authors: STEVENS J. E.
Published: February 2007

A case of rebound hypertension under anaesthesia, following withdrawal of clonidine, is described and methods of treatment outlined.
Difficult extubation
Authors: LALL N. G.
Published: February 2007

Difficulty was encountered during extubation due to a fold in cuff of a tracheal tube at its distal end. Management of this unexpected and rare complication is described.
Normocapnic anaesthesia with enflurane for intraocular surgery
Authors: ROSE N.M. , ADAMS A.P.
Published: February 2007

The intraocular pressure was measured by applanation tonometry in 13 patients undergoing lens extraction with normocapnic anaesthesia with 1 % enflurane and controlled ventilation of the lungs with large tidal volumes (13 ml/kg). The intraocular pressure was consistently reduced by about 35% and was associated with a similar reduction in systolic arterial pressure. Provided care is taken with those patients with hypertension or heart disease who might become hypotensive, the technique is suitable for lens extraction surgery especially where it is desirable to avoid the administration of halothane.
Alphaxalone infusion during cardiopulmonary bypass
Authors: CONIAM S.W.
Published: February 2007

A continuous infusion of alphaxalone (as Althesin) was used to maintain anaesthesia for patients undergoing open heart surgery. Plasma levels of the drug were measured at intervals during the procedure. It was found that alphaxalone was adequately removed from the circulation, despite a period of cardiopulmonary bypass and hypothermia, and provided suitable anaesthesia for this type of surgery.
Systemic side‐effects of extradural steroids
Authors: KNIGHT C.L. , BURNELL J.C.
Published: February 2007

The use of extradural (epidural) steroids in the management of selected cases of lumbosciatic syndrome is well known.1,2 This paper reports the appearance of systemic side‐effects in four cases after each had received an injection of 6–10 ml of methylprednisolone and 0·25% bupivacaine into the extradural space at the site nearest to the affected nerve roots.
Mixing of antacids with stomach contents
Authors: HOLDSWORTH J.D. , JOHNSON K. , MASCALL G. , ROULSTON R. GWYNNE , TOMLINSON P.A.
Published: February 2007

An investigation was carried out into the readiness with which magnesium trisilicate mixture BPC, Andursil suspension (Geigy) and 0·33 M aqueous sodium citrate mixed with gastric contents, to evaluate their suitability for use as an antacid before the induction of anaesthesia in obstetric patients.

Laboratory investigations demonstrated that magnesium trisilicate and Andursil did not mix adequately with gastric contents, whereas sodium citrate mixed readily. A clinical investigation of sodium citrate revealed significant improvement in the mixing of gastric juice with the antacid if the patient was turned into the right lateral position following its administration (p <0·05), but highly significant improvement followed a rotation through 360° (p<0·005).

It was thought that these findings were caused by the division of the stomach into two sacs, a phenomenon confirmed by radiological studies and the use of a pig's stomach as a model of the human stomach.
The choice of anaesthesia as a career by undergraduates in a developing country
Authors: Akinyemi O.O. , Soyannwo A.O.
Published: February 2007

The choice of anaesthesia as a future career by 54 undergraduates of the University College Hospital, Ibadan, Nigeria was studied. None of the students selected anaesthesia as first choice; the specialty ranked sixth. The short duration of exposure to anaesthesia, insufficient participation in practical anaesthesia during their posting and inadequate provision of teaching aids were considered by the students to require improvement. The authors also suggest early introduction of anaesthesia in their curriculum.
Nominal group technique
Authors: HORTON J.N.
Published: February 2007

Committee‐work which involves decision‐making from a range of alternatives is frequently time‐consuming, inefficient, and frustrating. Nominal Group Technique is a structured method of group decision‐making which allows a rich generation of original ideas, balanced participation of all members of the group, and a rank‐ordered set of decisions based on a mathematical voting method. A brief description of a Nominal Group Technique session is given and its application to decision‐making by committees of anaesthetists is illustrated by an example.
Anaesthesia and demyelinating disease
Authors: JONES R.M. , HEALY T.E.J.
Published: February 2007

The demyelinating diseases are classified and the current concepts of the aetiology and pathophysiology of the most common of these diseases, multiple sclerosis, are described. The effects of the impaired function, local responses and known complications of the disease on the choice of anaesthetic, drugs and techniques are discussed.
Hyperkalaemia presenting as ventilatory failure
Authors: BARKER G. L.
Published: February 2007

This case report concerns a woman who became hyperkalaemic after an operation and required automatic ventilation.
Cold agglutinins
Authors: WILLIAMS A. C.
Published: February 2007

An unusual case of re‐exploration of the site of previous ventricular aneurysmectomy is reported. The conduct of cardiopulmonary bypass was complicated by the presence of cold agglutinins with a wide thermal range active up to 30°C. There follows a brief description of cold agglutinins, and the difficulties they cause during cross‐matching.
Early opposition to obstetric anaesthesia
Authors: FARR A.D.
Published: February 2007

Some of the arguments used to oppose the introduction of inhalation anaesthesia–especially in obstetrics—are considered. These arguments were mainly based upon a desire to retain the sensation of pain, either as a factor necessary for survival or as a diagnostic aid: moral arguments were also adduced but religious opposition is no more than a myth of historiography. The opposition to anaesthesia lasted for less than 15 years and is seen as essentially a reflection of contemporary views on the role of pain.
Human volunteer studies of Alfentanyl (R39209), a new short‐acting narcotic analgesic
Authors: KAY B. , PLEUVRY B.
Published: February 2007

Alfentanyl is a new narcotic analgesic with a rapid onset and very short duration of effect, and a potency about one third of that of fentanyl.

The respiratory effects of 1·6, 3·2 and 6·4 μg/kg Alfentanyl were studied in a randomised controlled trial in five volunteers. Alfentanyl 6·4 μg/kg induced a significant increase in respiration at 1 minute, then significant depression of mean minute volume 3 and 4 minutes after slow intravenous injection, compared with saline control, and pre‐injection values. Mean end‐expired carbon dioxide concentration was increased after Alfentanyl 6·4 μg/kg, significantly from 2 to 9 min after injection, and highly significantly at 3,4 and 5 minutes. Examination of the effect on expired CO2 concentration at 4 minutes reveals a highly significant dose‐response relationship with the three doses of Alfentanyl.

The transient effect of Alfentanyl was confirmed by the fact that no change in mean ventilatory response to carbon dioxide was demonstrable 30 or 50 minutes after any dose. When Alfentanyl was given 1 minute before testing the ventilatory response to carbon dioxide the response curves showed a highly significant dose‐related shift to the right.

There were no significant changes in heart rate or blood pressure after Alfentanyl, but the drug produces the typical subjective effects of the opiates.
Contamination of internal jugular lines
Authors: OPIE J.C.
Published: February 2007

From July to December 1977, 217 patients underwent open heart surgery at this institution. From this group, 125 internal jugular venous lines (JVL) were collected, cultured and the organisms identified. Nose, throat, urine and sternotomy wounds were also cultured. Notable findings included a JVL contamination rate of 65%. The commonest infecting organism (90%) was Staphylococcus epidermidis (albus). This organism was also found in the nares in 74% of cases, but was not isolated from other sites. Postoperative pyrexia, but no morbidity or mortality, could be related to the JVL contamination.

It was concluded that the source of the JVL contamination was the patients' neck skin, which itself is contaminated by the patients' noses.
Glycopyrrolate in children
Authors: LAVIS D. M. , LUNN J. N. , ROSEN M.
Published: February 2007

The effect of intravenous administration of glycopyrrolate and atropine shortly before induction were compared in a double blind study in children. The study shows that glycopyrrolate, unlike atropine, administered before anaesthesia had little effect on heart rate. The heart rate changes at, and following, tracheal intubation were similar in both groups.
Hypoglycaemic coma following epidural analgesia
Authors: ROMANO E. , GULLO A.
Published: February 2007

A diabetic patient who was taking an intermediate‐acting insulin preparation developed sudden hypoglycaemic coma after epidural analgesia between T5 and L1. Several diagnostic possibilities are discussed.

It is concluded that prophylactic intravenous infusion of glucose and small doses of local anaesthetic are always advisable in diabetic patients having epidural analgesia.
Anaesthesia for surgical correction of fractured femoral neck A comparison of three techniques
Authors: White I.W.C. , Chappell W.A.
Published: February 2007

Sixty patients with fractured neck of femur and scheduled for surgical correction were randomly allocated to receive one of three anaesthetic techniques: general anaesthesia; spinal analgesia; psoas compartment block. The patients in the local anaesthetic groups also received a light general anaesthetic. There was little difference in the pre‐, intra‐ and postoperative events, and no difference in postoperative mortality.
Corrective cardiac surgery in infants
Authors: MANNERS J.M. , MONRO J.L. , EDWARDS J.C.
Published: February 2007

This is a review of 136 patients who have undergone corrective surgery for congenital heart disease with the aid of profound hypothermia in a 6‐year period. Almost all patients were less than one year old and less than 10 kg. In 1979 the average age was 3·4 months and the average weight was 4·1 kg in 34 infants. The hypothermic technique consisted of surface cooling followed by cardiopulmonary bypass cooling and circulatory arrest during definitive surgery. The hospital mortality was 26% for the whole period, having decreased from 53% in 1974 to 15% in 1979. After operation 70% of patients with uncomplicated ventricular septal defect or the tetralogy of Fallot were extubated within 4 hours, 65% of all patients were extubated within 12 hours of operation.
Maternal opinion about analgesia for labour
Authors: ROBINSON J.O. , ROSEN M. , EVANS J.M. , REVILL SUSAN I. , DAVID H. , REES G.A.D.
Published: February 2007

In a randomised controlled trial epidural analgesia with bupivacaine 0·5% (mean dose 112·8 mg) was compared with pethidine (mean dose 200 mg) and inhalational analgesia in primipara (28 and 30 mothers) and multipara (17 and 18 mothers). Mothers who had an uneventful pregnancy and labour and agreed to have either treatment were studied during labour and followed‐up at interviews for 5 months after delivery. Epidural block was rated significantly superior in respect of pain relief and comfort, there were no differences between the groups in reports of perineal discomfort. Twice as many primipara required forceps delivery after epidural block. Very few mothers, in each group, reported something missing in their experience of childbirth. Two thirds of each group would use the same method again. Epidural block can therefore be recommended to uncommitted mothers as a satisfying and effective method of pain relief for labour.
Windows in the intensive therapy unit
Authors: KEEP PHILIP , JAMES JOSEPHINE , INMAN MICHAEL
Published: February 2007

Retrospective surveys were carried out on two groups of patients who had survived a stay of at least 48 h in an Intensive Therapy Unit. One group had been kept in a unit without windows, and the other in a similar unit with translucent but not transparent windows.

Survivors from the windowless unit had a less accurate memory of the length of their stay, and were less well orientated in time during their stay. The incidence of hallucinations and delusions was more than twice as high in the windowless unit.

The phenomenon of depersonalisation in the face of life‐threatening danger is described and discussed.
Colloid osmotic pressure
Authors: BEVAN D.R.
Published: February 2007

Technical advances have made the bedside measurement of colloid osmotic pressure (COP) a rapid and reproducible test. The principles of measurement are described and the place of COP determinations in the recognition, treatment and prophylaxis of oedematous states is discussed.
Cor pulmonale and the Pierre Robin anomaly
Authors: FREEMAN M.K. , MANNERS J.M.
Published: February 2007

An infant with Pierre Robin anomaly was anaesthetised for cardiac catheterisation. There was cor pulmonale with the pulmonary artery pressure at systemic level, a patent foramen ovale and a persistent ductus arteriosus. The effects of alterations in blood gases on the haemodynamics and intracardiac shunts are considered. Subsequent management of the obstructed airway with a nasopharyngeal tube for 4 weeks is described.
Endotracheal intubation with the fibre‐optic bronchoscope
Authors: Messeter K.H. , Pettersson K.I.
Published: February 2007

Tracheal intubation with the aid of the fibre‐optic bronchoscope was compared to conventional and alternative methods in 41 consecutive patients suffering from advanced rheumatoid arthritis. All patients were scheduled for anterior and/or posterior cervical fusion. It was shown that the use of the fibre‐optic bronchoscope significantly diminished the number of complicated intubations and reduced the intubation trauma considerably. The occurrence of postoperative upper airway oedema was significantly related to the extent of the intubation trauma. Tracheal intubation with the fibre‐optic bronchoscope is considered useful in adult patients when intubation is expected to be difficult or dangerous and when orthodox intubation is found to be very difficult.
Maternal death
Authors: MORGAN B.M.
Published: February 2007

A retrospective examination of all maternal deaths at Queen Charlotte's Hospital in the last 20 years shows that general anaesthesia is the greatest single cause of maternal death. This highlights the need for considerable reduction in the inherently dangerous technique of general, anaesthesia to patients in labour and, where possible, its replacement by extradural and spinal blocks.
Methylprednisolone prior to cardiopulmonary bypass
Authors: THOMPSON M.A. , BROADBENT M.P.
Published: February 2007

Patients undergoing cardiopulmonary bypass were randomly allocated to receive methylprednisolone 30 mg/kg in a single dose prior to bypass, or to a control group receiving saline. The effect of this treatment on 2,3‐DPG and oxygen delivery to the tissues was determined.

There was no difference between the groups in 2,3‐DPG levels, P50 or oxygen availability, but the methylprednisolone group showed a highly significant difference in oxygen consumption immediately following cardiopulmonary bypass (p < 0·001) and a significant difference in serum phosphate levels in the immediate postoperative period (p < 0·05). Methylprednisolone levels were measured by radioimmunoassay, and these showed a rapid decline in the 4 hours following administration.
A neurological complication following interscalene brachial plexus block
Authors: BARUTELL C. , VIDAL F. , RAICH M. , MONTERO A.
Published: February 2007

A case is reported of the unfortunate development of permanent neurological damage to the motor outflow of at least two of C7, C8 and T1 motor nerve roots; following an attempted block of the brachial plexus using the interscalene approach.
Spinal analgesia for instrumental delivery
Authors: Hutchins C.J.
Published: February 2007

One hundred and eighty‐three patients undergoing instrumental delivery were randomly divided into two groups, one of which received low spinal anaesthesia and the other pudendal nerve block for delivery. Both were administered by the operator. No patient who received spinal anaesthesia experienced pain. 62% of patients who had a rotational delivery under pudendal nerve block experienced severe pain; 15% had pain during direct delivery. Hypotension was not observed. The incidence of postnatal complications was similar in each group. Low spinal anaesthesia in the hands of the operator provided superior anaesthesia with no increase in complications.
Chlormethiazole as sleep cover for the elderly. Intravenous infusion during local analgesia
Authors: Marley John E. , Ward Stephen
Published: February 2007

A method of avoiding postoperative confusion when local analgesic techniques are indicated for the elderly is described. Basal sedation using 0·8% chlormethiazole infusion intravenously, was employed. Mental function was not altered when the technique was used and it is suggested that the length of stay in hospital can be reduced.
Automatic ventilation with the Ayre's T‐piece
Authors: NEWTON N.I. , HILLMAN K.M. , VARLEY J.G.
Published: February 2007

A simple modification to an existing adult ventilator has been designed to permit mechanical ventilation of neonates and small children with the Ayre's T‐piece circuit.

The Nuffeld Anaesthesia Ventilator Series 200 has been modified by replacing the piston in the patient valve with a fixed leak. This arrangement avoids the problems of critical adjustment commonly encountered with other methods of converting adult ventilators to paediatric use, and allows the ventilator controls to be used normally.

The ventilator has been assessed according to the proposed International Standards Organization specifications for the evaluation of the performance of lung ventilators, and the results are described in detail.

The modified ventilator is shown to perform as a time‐cycled pressure generator capable of delivering tidal volumes between 10 and 300 ml at frequencies from 10 to 85/minute. It is therefore ideally suited to neonatal and paediutric use.
Tourniquet failure and arterial calcification
Authors: JEYASEELAN S. , STEVENSON T.M. , PFITZNER J.
Published: February 2007

A patient with Mönckeberg's calcinosis is presented in whom a pneumatic limb tourniquet failed to be effectitie because of calcification of the femoral artery wall. Bleeding from the operation site was noticed to be appreciably greater while the tourniquet was inflated since the cuff, though not occluding the femoral artery, acted as a very effective venous tourniquet.

Theoretical risks which might be associated with the use of tourniquets in the presence of arterial calcification are fracture of the calcified vessel wall and systemic overdose of local anaesthetic agent following attempted regional intravenous block.

The problem of tourniquet failure in general, and the dangers which might be associated with the use of tourniquets in patients with incompressible arteries, are briefly discussed.