Showing papers by "Malcolm L. H. Green published in 1996"
584 citations
TL;DR: Magnetic femoral nerve stimulation is a painless, supramaximal method of assessing quadriceps strength and fatigue which is likely to be of value in clinical and physiological studies.
Abstract: There is no nonvolitional method of assessing quadriceps strength which both supramaximally activates the muscle and is acceptable to subjects. In 10 normal subjects and 10 patients with suspected muscle weakness we used magnetic stimulation of the femoral nerve to elicit an isometric twitch and measured twitch tension (TwQ), surface electromyogram in addition to the maximum voluntary contraction force (MVC). Supramaximality was achieved in all subjects at a mean of 83% of maximum stimulator output. When supramaximal, TwQ was reproducible (mean coefficient of variation 3.6%, range 0.7-10.9) and correlated well with MVC (r2 = 0.83, P<0.001). In 7 normal subjects we measured TwQ before and after a fatiguing protocol; after 20 min TwQ was a mean of 55% (range 29-77%) of baseline and remained substantially reduced at 90 min. Magnetic femoral nerve stimulation is a painless, supramaximal method of assessing quadriceps strength and fatigue which is likely to be of value in clinical and physiological studies.
217 citations
TL;DR: BAMPS is easy, well tolerated and can be used in the supine subject and partitioning of Pes and Pgas were very close for BAMPS and BES, suggesting similar specificity for the diaphragm.
Abstract: We investigated whether bilateral magnetic stimulation of the phrenic nerves from an anterolateral approach (BAMPS) could combine the reproducibility and ease of use of cervical magnetic stimulation (CMS) with the specificity of bilateral electrical stimulation (BES) and whether it could be used in supine subjects. We placed two double 43-mm coils over the phrenic nerves in the neck. BAMPS produced supramaximal phrenic stimulation by electromyogram (EMG) assessment in six of seven subjects. There was no significant difference in the twitch gastric pressure/twitch esophageal pressure ratio (twitch Pgas/Pes) between BAMPS (1.2) and BES (1.3). Both differed from CMS (0.9, p < 0.001). The effect of a change in posture on twitch transdiaphragmatic pressure (TwPdi) and Pgas/Pes ratio was the same for BAMPS and BES. In normal subjects and patients BAMPS correlated significantly with BES (r = 0.97), maximal sniffs (r = 0.85), and CMS (r = 0.92). The mean difference between BAMPS and BES was 0.3 cm H2O (SD = 2.3). Two-minute maximal isocapnic ventilation produced a 19% fall in TwPdi elicited by BAMPS. BAMPS is easy, well tolerated and can be used in the supine subject. TwPdi and partitioning of Pes and Pgas were very close for BAMPS and BES, suggesting similar specificity for the diaphragm.
179 citations
TL;DR: In this article, the synthesis of carbon nanotubes filled with silver, gold, and gold chloride is described, and the resulting materials have been studied by high-resolution electron microscopy, X-ray powder diffraction, and energy-dispersive spectroscopy (EDS).
Abstract: The synthesis of carbon nanotubes filled with silver, gold, and gold chloride is described. The resulting materials have been studied by high-resolution electron microscopy, X-ray powder diffraction, and energy-dispersive spectroscopy (EDS). The EDS data were obtained using a high-resolution electron microscope equipped with a field emission gun which allowed for X-ray analytical data to be obtained on individual particles located within the carbon nanotubes using a 0.7 nm probe.
103 citations
91 citations
TL;DR: It is concluded that after maximal ventilation in humans there is a reduction of twitch Pga and, therefore, of low-frequency fatigue in abdominal muscles.
Abstract: Kyroussis, Dimitris, Gary H. Mills, Michael I. Polkey, Carl-Hugo Hamnegard, Nicholaos Koulouris, Malcolm Green, and John Moxham. Abdominal muscle fatigue after maximal ventilation in humans. J. App...
81 citations
TL;DR: TwPDI following magnetic stimulation of the phrenic nerves is a clinically useful measurement when assessing diaphragm weakness, and is similar with magnetic and electrical stimulation.
Abstract: BACKGROUND: Accurate assessment of diaphragm strength can be difficult. Transdiaphragmatic pressure (PDI) measurements during volitional manoeuvres are useful but it may be difficult to ensure maximum patient effort. Magnetic stimulation of the phrenic nerves is easy to perform and the results are reproducible in normal subjects. The purpose of the present study was to evaluate the usefulness of magnetic stimulation of the phrenic nerves in the assessment of diaphragm weakness in patients. METHODS: Sixty-six patients referred for assessment of respiratory muscle strength and 23 normal subjects were studied. Twitch PDI (TwPDI) following magnetic stimulation of the phrenic nerves and sniffPDI were obtained in all individuals. TWPDI following bilateral electrical stimulation of the phrenic nerves was also obtained in eight patients. RESULTS: Mean (SD) TwPdi for the normal subjects was 31 (6) cm H2O and 18 (11) cm H2O for the patients. TwPDI and sniffPDI were correlated (r = 0.77). Seven of the 37 patients (19%) with a reduced sniffPDI had a TwPDI within the normal range whereas two of the 32 patients (6%) with a reduced TwPDI had a normal sniffPDI. TwPDI was similar with magnetic and electrical stimulation. CONCLUSIONS: TwPDI following magnetic stimulation of the phrenic nerves is a clinically useful measurement when assessing diaphragm weakness.
69 citations
TL;DR: The new ansa-bridged mono-and bi-nuclear Group IV metallocenes were described in this paper, where they are catalysts for the polymerisation of ethene and propene.
61 citations
TL;DR: In this paper, the authors describe the preparation, characterization, and properties of all nonpolymeric complexes that contain a metal σ- or π-bound to a fullerene.
Abstract: Publisher Summary This chapter discusses organometallic complexes of fullerenes. The solid-state and organic chemistries of fullerenes are currently active areas of research with possible applications, for instance, in the field of superconductivity. The chapter describes the preparation, characterization, and properties of all nonpolymeric complexes that contain a metal σ- or π-bound to a fullerene. They readily react with many electron-rich metal centers to form stable π or σ complexes. Although the π complexes have not yet found any practical uses, they have proved helpful in structural characterization, as well as providing some insight into the dynamical behavior of fullerenes. The σ complexes are a relatively unexplored area, but where they have been prepared, they are useful intermediates in the preparation of organic fullerene adducts. As a result, fullerenes are more reactive than might be expected and behave like giant closed-cage alkenes rather than super arenes.
55 citations
TL;DR: In this article, the synthesis of continuous and crystallographically aligned single crystals of molybdenum oxide based nanowires up to micrometres in length inside carbon nonotubes is described.
46 citations
TL;DR: The compound [Zr(η-C5H5] with B(C6F5)3 in benzene or dichloromethane gave ZrIII (η)-C5 H5).
Abstract: The compounds [Zr(η-C5R5){η-CPh(NSiMe3)2}R′2](R = H, R′= Me or CH2Ph; R = Me, R′= Me) reacted with [Ph3C][B(C6F5)4] giving [{Zr(η-C5H5)[η-CPh(NSiMe3)2]}2(µ-Cl)2][BX(C6F5)3]2[R = H, X = Me or CH2Ph; R = Me, X = C6F5(crystal structure)] Treatment of [Zr(η-C5H5){η-CPh(NSiMe3)2}Me2] with B(C6F5)3 gave [(C6F5){η-(Me3SiN)2PhC}(η-C5 H5)Zr(µ-Me)B(C6F5)3](crystal structure) The compound [Zr(η-C5H5){η-CPh(NSiMe3)2}(CH2Ph)2] with B(C6F5)3 in benzene or dichloromethane gave [ZrIII(η-C5H5){η-CPh(NSiMe3)2}L][B(CH2Ph)(C6F5)3](L = C6H6 or CH2Cl2)
TL;DR: The metallocenes as cocatalysts for the polymerisation of ethene and propene have been evaluated in this paper, and the activity of the metallocene as a cocatalyst for polymerization of propene has been evaluated.
Abstract: The new ansa-metallocenes [M{Me2C(η-C5H4)(η2-C9H6)}(η-C5H5)Cl][M = Zr (crystal structure) or, Hf], [M{(CH2)5C(η-C5H4)(η2-C9H6)}(η-C5H5)Cl]·0.5C6H5Me [M = Zr (crystal structure) or Hf], [Zr{Me2C(η-C5H4)(η3-C13H8)}(η-C5H5)Cl](crystal structure), [M{Me2C(η-C5H4)2}(η-C5H5)Cl][M = Zr or Hf (crystal structures)], [X2(η-C5H5)M{C5H4(CMe2)C9H6)}M*(η-C5H5)X 2}](X = Cl, M, M*= Zr, Zr; Hf, Hf; Zr, Hf; or Hf, Zr; X = Me, M, M*= Zr, Zr; Zr, Hf; Hf, Zr; or Hf, Hf), [Cl2(η-C5H5)Zr{C5H4(CMe 2)C9H6}Zr(η-C5Me5)Cl2], [{M(C5H4CMe2C9H7)}(η-C5H5)Cl2](M = Zr or Hf) and [Zr{C5H4CMe2(C9H7}(η-C 5H5)Me2] have been prepared and characterised. The activity of the metallocenes as cocatalysts for the polymerisation of ethene and propene has been evaluated.
TL;DR: The structure, morphology and surface topography of multilayer carbon nanotubes have been studied by transmission electron microscopy and atomic force microscopy (AFM) as discussed by the authors, and it has been found that a large proportion of carbon tubes have a cylindrical shaped body, with a significant number being polygonal in appearance.
Journal Article•
TL;DR: In this paper, a microwave-induced argon plasma (MIAP) was used for the synthesis of alkali metal fullerides using a 13C MAS NMR spectroscopy and powder X-ray Rietveld analysis.
Abstract: The rapid synthesis of alkali metal fullerides using a microwave-induced argon plasma (MIAP) is reported. Reaction times are of the order of seconds using a MIAP, whereas conventional synthesis requires times of the order of several days. Potassium, rubidium, and cesium fullerides are more readily synthesized by this technique than sodium fullerides. Investigation of sodium fulleride synthesis via both conventional and microwave routes, combined with 13C MAS NMR spectroscopy and powder X-ray Rietveld analysis, gives an improved understanding of the sodium−C60 phase diagram.
TL;DR: In this paper, the synthesis and crystal structure of the η-cyclopentadienylniobium compound [Nb(η-C5H5)Cl2(NOBut)], which contains the first example of the terminal transition metal-alkoxylimide ligand system MN-OR, was reported along with some preliminary reactivity studies.
TL;DR: In this paper, the synthesis of the η-lutidine(η-allyl)molybdenum compounds [Mo(2,6- lutidine)(η -C3H5)Cl] and [Mo[Mo[2,2, 6]-cl] are described.
TL;DR: In this article, a method for selective removal of material from the outside of filled carbon nanotubes is exemplified for rhodium trichloride filled tubes: the purification proceeds by washing with the reversed micelle mixture, dodecylammonium propionate (dap)-solubilized water in benzene.
TL;DR: The thermal reaction of [Nb(η-C 5 H 5 ) 2 H 3 ] with SiMe 3 H gives the bis-silyl fragment, which can be trapped by PMe 3 to give the fragment fragment which can also readily lose SiME 3 H; thus, it is readily methylated to yield the tungsten bis-stannyl fragment which is deprotonated by n BuLi to give weakly nucleophilic anion as discussed by the authors.
TL;DR: In this article, the preparation of [N(CH3)4]C60· 1.5thf and characterisation of its electronic properties, using susceptibility, EPR and 13C MAS NMR measurements, are reported.
Abstract: The preparation of [N(CH3)4]C60· 1.5thf and characterisation of its electronic properties, using susceptibility, EPR and 13C MAS NMR measurements, is reported. X-Ray powder diffraction shows a simple hexagonal stacking sequence of close-packed C60 layers, with cations and solvent molecules located in the trigonal-prismatic sites. The electronic properties are consistent with narrow-band metallic behaviour at high temperature. A transition in susceptibility and EPR measurements is seen between 200 and 230 K. A similar synthesis affords a C602– compound with the same simple hexagonal fulleride packing.
TL;DR: The compounds Ph(CH2)3B(OH)2I, [Ph(CH 2)3BO]3II, Ph( CH2)2CHCH2}(CO)2(PPh3) as mentioned in this paper have π-donor η-arene ligands which also bear a Lewis-acid σacceptor boron group.
Abstract: The compounds Ph(CH2)3B(OH)2I, [Ph(CH2)3BO]3II, Ph(CH2)3B(1,2-O2C6H4)III, Ph(CH2)3BC8H14IV(BC8H14= 9-borabicyclo[3.3.1]nonan-9-yl), [Cr{η-Ph(CH2)3B(1,2-O2C6H4)}(CO)3]1, [Cr{η-Ph(CH2)3BC8H14}(CO)3]2, [Cr{η-Ph(CH2)3BBr2·SMe2}(CO)3]3, [Cr{η-Ph(CH2)4BC8H14}(CO)3]4, [Cr(η-Ph(CH2)4BC8H14}(CO)2(PPh3)]5, [Cr{η-PhCH2CHCH2}(CO)3]6, [Cr{η-Ph(CH2)2CHCH2}(CO)3]7, [Cr{η-Ph(CH2)2η-CHCH2}(CO)2]8, [Cr{η-Ph(CH2)2CHCH2}(CO)2(PPh3)]9, [Li(Et2O)n][Cr{η-PhCH2CHCH2}(CO)2{C(O)Ph}]10, [Li(Et2O)n][Cr{η-Ph(CH2)2CHCH2}(CO)2{C(O)Ph}]11, [Mo{η-Ph(CH2)3BC8H14}2]12 and [Cr{η-Ph(CH2)3BOC8H14}(CO)3]13, have been prepared and characterised. Compounds 1–5, 12 and 13 have π-donor η-arene ligands which also bear a Lewis-acid σ-acceptor boron group. There was no evidence that these boron groups formed ground-state intra- or inter-molecular interactions with the Lewis base functions of the carbonyl oxygen atoms.
TL;DR: In this paper, the reduction of nitric oxide by arc vaporized carbons (AVC) including the compound C 60, fullerene soot and carbon nanotubes, giving dinitrogen and carbon oxides has been studied.
Abstract: The reduction of nitric oxide by arc vaporized carbons (AVC) including the compound C 60 , fullerene soot and carbon nanotubes, giving dinitrogen and carbon oxides has been studied. It is found that the AVC carbons are more active towards oxidation by NO than by oxygen gas at low temperatures (300–400°C). In contrast, conventional carbons such as graphite and microporous carbons are more readily oxidised by oxygen than by NO. The addition of copper salts and to a lesser extent, cobalt salts, to fullerene soot substantially promote NO reduction. The high intrinsic activity for NO reduction by AVC carbons compared to graphitic carbons is attributed to the presence of five membered carbon rings in the AVC carbons.
TL;DR: In this paper, the reduction of nitric oxide by arc vaporized carbons (AVC) including the compound C 60, fullerene soot and carbon nanotubes, giving dinitrogen and carbon oxides has been studied.
Abstract: The reduction of nitric oxide by arc vaporized carbons (AVC) including the compound C 60 , fullerene soot and carbon nanotubes, giving dinitrogen and carbon oxides has been studied. It is found that the AVC carbons are more active towards oxidation by NO than by oxygen gas at low temperatures (300–400°C). In contrast, conventional carbons such as graphite and microporous carbons are more readily oxidised by oxygen than by NO. The addition of copper salts and to a lesser extent, cobalt salts, to fullerene soot substantially promote NO reduction. The high intrinsic activity for NO reduction by AVC carbons compared to graphitic carbons is attributed to the presence of five membered carbon rings in the AVC carbons.