Managing the challenge of IABP therapy.

The nurse's role requires the operation of the IABP, while at the same time, the ability to deliver quality nursing care. Knowledge of physiology, coordination of the principles of timing with hemodynamic effects, and skillful problem solving assure critical care nurses that they can effectively manage the IABP challenge.

Challenges and rewards of educating a profoundly deaf student.

The faculty and administrators of a college of nursing in a public university learned that awareness of the Americans With Disabilities Act of 1990 is very different from complying with its mandates in the education of a profoundly deaf nursing student. The process began with many challenges and ended with rewards beyond the expectations of all involved. Faculty, who initially resisted the concept of educating a "deaf nurse," developed creative teaching strategies and ultimately gained a new perspective regarding who has the potential to become a good nurse. In the final analysis, everyone agreed that this exceptional young woman was not only our student, but was also our teacher.

Using an algorithm to interpret arterial blood gases.

The arterial blood gas (ABG) analysis, one of the most common tests ordered, provides clinicians with valuable information on a patient's oxygenation and acid-base balance. Interpreting ABG analysis results can be challenging, even for the most experienced practitioners, because it requires knowledge of the physiology and cause-and-effect relationship of the disturbances. Applying the principles and the ABG algorithm described in this article will provide nurses with a systematic way to interpret uncomplicated arterial blood gas results, including primary, mixed, and compensated acidbase disturbances.

Note: High density pulsed molecular beam for cold ion chemistry.

A recent expansion of cold and ultracold molecule applications has led to renewed focus on molecular species preparation under ultrahigh vacuum conditions. Meanwhile, molecular beams have been used to study gas phase chemical reactions for decades. In this paper, we describe an apparatus that uses pulsed molecular beam technology to achieve high local gas densities, leading to faster reaction rates with cold trapped ions. We characterize the beam's spatial profile using the trapped ions themselves. This apparatus could be used for preparation of molecular species by reactions requiring excitation of trapped ion precursors to states with short lifetimes or for obtaining a high reaction rate with minimal increase of background chamber pressure.

Spin-dependent WIMP limits from a bubble chamber.

Bubble chambers were the dominant technology used for particle detection in accelerator experiments for several decades, eventually falling into disuse with the advent of other techniques. We report here on a new application for these devices. We operated an ultraclean, room-temperature bubble chamber containing 1.5 kilograms of superheated CF3I, a target maximally sensitive to spin-dependent and -independent weakly interacting massive particle (WIMP) couplings. An extreme intrinsic insensitivity to the backgrounds that commonly limit direct searches for dark matter was measured in this device under operating conditions leading to the detection of low-energy nuclear recoils like those expected from WIMPs. Improved limits on the spin-dependent WIMP-proton scattering cross section were extracted during our experiments, excluding this type of coupling as a possible explanation for a recent claim of particle dark-matter detection.

Identification of weakly interacting massive particles through a combined measurement of axial and scalar couplings.

We study the prospects for detecting weakly interacting massive particles (WIMPs) in a number of phenomenological scenarios, with a detector composed of a target simultaneously sensitive to both spin-dependent and spin-independent couplings, as is the case of COUPP (Chicagoland Observatory for Underground Particle Physics). First, we show that sensitivity to both couplings optimizes chances of initial WIMP detection. Second, we demonstrate that, in case of detection, a comparison of the signal on two complementary targets, such as in COUPP CF3I and C4F10 bubble chambers, allows a significantly more precise determination of the dark matter axial and scalar couplings. This strategy would provide crucial information on the nature of the WIMPs and possibly allow discrimination between neutralino and Kaluza-Klein dark matter.

New measurement of the electron magnetic moment using a one-electron quantum cyclotron.

A new measurement resolves cyclotron and spin levels for a single-electron quantum cyclotron to obtain an electron magnetic moment, given by g/2=1.001 159 652 180 85 (76) [0.76 ppt]. The uncertainty is nearly 6 times lower than in the past, and g is shifted downward by 1.7 standard deviations. The new g, with a quantum electrodynamics (QED) calculation, determines the fine structure constant with a 0.7 ppb uncertainty--10 times smaller than for atom-recoil determinations. Remarkably, this 100 mK measurement probes for internal electron structure at 130 GeV.

New determination of the fine structure constant from the electron value and QED.

Quantum electrodynamics (QED) predicts a relationship between the dimensionless magnetic moment of the electron (g) and the fine structure constant (alpha). A new measurement of g using a one-electron quantum cyclotron, together with a QED calculation involving 891 eighth-order Feynman diagrams, determine alpha(-1)=137.035 999 710 (96) [0.70 ppb]. The uncertainties are 10 times smaller than those of nearest rival methods that include atom-recoil measurements. Comparisons of measured and calculated g test QED most stringently, and set a limit on internal electron structure.

Single-particle self-excited oscillator.

Electronic feedback is used to self-excite the axial oscillation of a single electron in a Penning trap. Large, stable, easily detected oscillations arise even in an anharmonic potential. Amplitudes are controlled by adjusting the feedback gain, and frequencies can be made nearly independent of amplitude fluctuations. Quantum jump spectroscopy of a perpendicular cyclotron motion reveals the absolute temperature and amplitude of the self-excited oscillation. The possibility to quickly measure parts per billion frequency shifts could open the way to improved measurements of e(-), e(+), p, and (-)p magnetic moments.

Feedback cooling of a one-electron oscillator.

A one-electron oscillator is cooled from 5.2 K to 850 mK using electronic feedback. Novel quantum jump thermometry reveals a Boltzmann distribution of oscillator energies and directly measures the corresponding temperature. The ratio of electron temperature and damping rate (also directly measured) is observed to be a fluctuation-dissipation invariant, independent of feedback gain, as predicted for noiseless feedback. The sharply reduced linewidth that results from feedback cooling illustrates the likely importance for improved fundamental measurements and symmetry tests.

Toxic effects of benzene and benzene metabolites on mononuclear phagocytes.

Benzene is a potent bone marrow toxin in animals and man. Animal studies have shown that exposure to benzene can alter T lymphocyte functions and decrease the resistance of animals to Listeria monocytogenes and transplanted tumor cells. Mononuclear phagocytes participate in host resistance to Listeria and tumor cells. The purpose of the studies presented here was to determine the effects of benzene and benzene metabolites on macrophage functions and the ability of macrophages to be activated for functions which are important in host defense. Benzene had no effects on macrophage function or activation for any of the functions tested. Conversely, metabolites of benzene, catechol (CAT), hydroquinone (HQ), benzquinone (BQ), and 1,2,4-benzenetriol (BT) had potent and varied effects on macrophage function and activation. BQ inhibited the broadest range of functions including release of H2O2, Fc receptor-mediated phagocytosis, interferon gamma priming for tumor cell cytolysis, and bacterial lipopolysaccharide (LPS) triggering of cytolysis. BQ was also the most potent metabolite causing inhibition at lower concentrations than the other metabolites. HQ inhibited H2O2 release and priming for cytolysis and BT inhibited phagocytosis and priming for cytolysis. CAT only inhibited the release of H2O2. None of the compounds tested inhibited the induction of class II histocompatibility antigens on the cell surface. All of the effects measured occurred using concentrations of compounds which did not disrupt the cell integrity or inhibit general functions such as protein synthesis. Taken together these data suggest that benzene metabolites alter macrophage function through several mechanisms including inhibition of output enzymes and disruption of signal transduction systems.