Objectives: To compare the efficacy of hypnotherapy versus gabapentin for the treatment of hot flashes in breast cancer survivors, and to evaluate the feasibility of conducting a clinical trial comparing a drug with a complementary or alternative method (CAM).
Design: Prospective randomised trial.
Setting: Breast health centre of a tertiary care centre.
The hydrogen atom is one of the most important and influential model systems in modern physics. Attempts to understand its spectrum are inextricably linked to the early history and development of quantum mechanics. The hydrogen atom's stature lies in its simplicity and in the accuracy with which its spectrum can be measured and compared to theory.
View Article and Find Full Text PDFCharges in cold, multiple-species, non-neutral plasmas separate radially by mass, forming centrifugally separated states. Here, we report the first detailed measurements of such states in an electron-antiproton plasma, and the first observations of the separation dynamics in any centrifugally separated system. While the observed equilibrium states are expected and in agreement with theory, the equilibration time is approximately constant over a wide range of parameters, a surprising and as yet unexplained result.
View Article and Find Full Text PDFWe demonstrate controllable excitation of the center-of-mass longitudinal motion of a thermal antiproton plasma using a swept-frequency autoresonant drive. When the plasma is cold, dense, and highly collective in nature, we observe that the entire system behaves as a single-particle nonlinear oscillator, as predicted by a recent theory. In contrast, only a fraction of the antiprotons in a warm plasma can be similarly excited.
View Article and Find Full Text PDFAntimatter was first predicted in 1931, by Dirac. Work with high-energy antiparticles is now commonplace, and anti-electrons are used regularly in the medical technique of positron emission tomography scanning. Antihydrogen, the bound state of an antiproton and a positron, has been produced at low energies at CERN (the European Organization for Nuclear Research) since 2002.
View Article and Find Full Text PDFWe report the application of evaporative cooling to clouds of trapped antiprotons, resulting in plasmas with measured temperature as low as 9 K. We have modeled the evaporation process for charged particles using appropriate rate equations. Good agreement between experiment and theory is observed, permitting prediction of cooling efficiency in future experiments.
View Article and Find Full Text PDFRev Sci Instrum
December 2009
A microchannel plate (MCP)/phosphor screen assembly has been used to destructively measure the radial profile of cold, confined antiprotons, electrons, and positrons in the ALPHA experiment, with the goal of using these trapped particles for antihydrogen creation and confinement. The response of the MCP to low energy (10-200 eV, <1 eV spread) antiproton extractions is compared to that of electrons and positrons.
View Article and Find Full Text PDFWe demonstrate temporally controlled modulation of cold antihydrogen production by periodic RF heating of a positron plasma during antiproton-positron mixing in a Penning trap. Our observations have established a pulsed source of atomic antimatter, with a rise time of about 1 s, and a pulse length ranging from 3 to 100 s. Time-sensitive antihydrogen detection and positron plasma diagnostics, both capabilities of the ATHENA apparatus, allowed detailed studies of the pulsing behavior, which in turn gave information on the dependence of the antihydrogen production process on the positron temperature T.
View Article and Find Full Text PDFControl of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report the first detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile and its relation to that of the electron plasma.
View Article and Find Full Text PDFWe have demonstrated storage of plasmas of the charged constituents of the antihydrogen atom, antiprotons and positrons, in a Penning trap surrounded by a minimum-B magnetic trap designed for holding neutral antiatoms. The neutral trap comprises a superconducting octupole and two superconducting, solenoidal mirror coils. We have measured the storage lifetimes of antiproton and positron plasmas in the combined Penning-neutral trap, and compared these to lifetimes without the neutral trap fields.
View Article and Find Full Text PDFAntihydrogen can be synthesized by mixing antiprotons and positrons in a Penning trap environment. Here an experiment to stimulate the formation of antihydrogen in the n = 11 quantum state by the introduction of light from a CO2 continuous wave laser is described. An overall upper limit of 0.
View Article and Find Full Text PDFWe have developed a new method, based on the ballistic transfer of preaccumulated plasmas, to obtain large and dense positron plasmas in a cryogenic environment. The method involves transferring plasmas emanating from a region with a low magnetic field (0.14 T) and relatively high pressure (10(-9) mbar) into a 15 K Penning-Malmberg trap immersed in a 3 T magnetic field with a base pressure better than 10(-13) mbar.
View Article and Find Full Text PDFAntihydrogen is formed when antiprotons are mixed with cold positrons in a nested Penning trap. We present experimental evidence, obtained using our antihydrogen annihilation detector, that the spatial distribution of the emerging antihydrogen atoms is independent of the positron temperature and axially enhanced. This indicates that antihydrogen is formed before the antiprotons are in thermal equilibrium with the positron plasma.
View Article and Find Full Text PDFWe demonstrate three-dimensional imaging of antiprotons in a Penning trap, by reconstructing annihilation vertices from the trajectories of the charged annihilation products. The unique capability of antiparticle imaging has allowed, for the first time, the observation of the spatial distribution of the particle loss in a Penning trap. The radial loss of antiprotons on the trap wall is localized to small spots, strongly breaking the azimuthal symmetry expected for an ideal trap.
View Article and Find Full Text PDFProduction of antihydrogen atoms by mixing antiprotons with a cold, confined, positron plasma depends critically on parameters such as the plasma density and temperature. We discuss nondestructive measurements, based on a novel, real-time analysis of excited, low-order plasma modes, that provide comprehensive characterization of the positron plasma in the ATHENA antihydrogen apparatus. The plasma length, radius, density, and total particle number are obtained.
View Article and Find Full Text PDFA theoretical underpinning of the standard model of fundamental particles and interactions is CPT invariance, which requires that the laws of physics be invariant under the combined discrete operations of charge conjugation, parity and time reversal. Antimatter, the existence of which was predicted by Dirac, can be used to test the CPT theorem-experimental investigations involving comparisons of particles with antiparticles are numerous. Cold atoms and anti-atoms, such as hydrogen and antihydrogen, could form the basis of a new precise test, as CPT invariance implies that they must have the same spectrum.
View Article and Find Full Text PDFUsing a novel technique for real-time transverse beam profile diagnostics of a stored ion beam, we have observed the transverse size of a stored laser-cooled ion beam. Earlier we observed that the density of the beam is independent of the beam current. At very low currents, we observe an abrupt change in this behavior: The vertical beam size increases suddenly by about an order of magnitude.
View Article and Find Full Text PDFFive patients with confirmed funnel-web spider bites (Hadronyche infensa) presented to Nambour General Hospital, in south-east Queensland, between 1992 and 1998. Two patients required antivenom; low doses of antivenom were effective. Patients were bitten in spring and early summer.
View Article and Find Full Text PDFThree-and-a-half years ago the barriers to communication between East and West Europe began to break down. Some of the news that first came through, particularly regarding the health care and living conditions of babies and children, was deeply disturbing and appeals were immediately launched for money, food, medical supplies and professional help. Later, equally tragic news was received about the plight of refugees and victims of the war in Bosnia.
View Article and Find Full Text PDFApical pneumothorax due to incomplete expansion of the lung is not uncommon following thoracotomy and also occurs in some patients with recurring spontaneous pneumothorax. Standard methods of intercostal drainage may be unsatisfactory because of difficulty in placing an intercostal tube safely and accurately within the apical air space.
View Article and Find Full Text PDFA prospective, controlled, randomized clinical study of 140 patients undergoing elective thoracic operations over a period of 1 year in a regional referral unit was performed in which one group received digoxin and the other did not. The incidence of cardiac arrhythmia was compared in each group. Overall mortality was 5.
View Article and Find Full Text PDFA 68-year-old woman was seen with recent-onset dysphagia. Investigations suggested a large retrocardiac tumor. At thoracotomy, a highly vascular tumor was found, involving the posterior and left aspect of the pericardium with attachment to the heart.
View Article and Find Full Text PDFEur J Cardiothorac Surg
April 1990
A case of oesophago-pericardial fistula following oesophagoscopy and dilatation is reported. This is a rare and usually fatal complication of oesophageal instrumentation. This case is of further interest as cardiac tamponade following a Niopam swallow subsequently occurred, and the patient survived emergency surgery.
View Article and Find Full Text PDF