Anomalous weak magnetism in superconducting YBa2Cu3O6+x.

For some time now, there has been considerable experimental and theoretical effort to understand the role of the normal-state "pseudogap" phase in underdoped high-temperature cuprate superconductors. Recent debate has centered on the question of whether the pseudogap is independent of superconductivity. We provide evidence from zero-field muon spin relaxation measurements in YBa2Cu3O6+x for the presence of small spontaneous static magnetic fields of electronic origin intimately related to the pseudogap transition. Our most significant finding is that, for optimal doping, these weak static magnetic fields appear well below the superconducting transition temperature. The two compositions measured suggest the existence of a quantum critical point somewhat above optimal doping.

Pericarditis in a patient with Legionnaires' disease.

Pericardial involvement with legionnaires' disease is rare. Pericarditis with legionnaires' pneumonia developed in a patient with previous mediastinal irradiation for Hodgkin's disease. Subsequently, the patient had progressive symptoms of pericardial constriction that required pericardiectomy. Acute infection with agents such as legionnaires' bacillus may precipitate the late appearance of pericardial disease in patients with previous mediastinal irradiation.

The affinity between continuous quality improvement and epidemic surveillance.

OBJECTIVE: To discuss the close affinity between the continuous quality improvement (CQI) concept of monitoring a process for the introduction of special causes and epidemic surveillance. DESIGN: A case study of a CQI tool for infection control epidemic surveillance. SETTING AND PATIENTS: A 668-bed acute care hospital with 5 intensive care units supporting heart, liver transplant, and trauma teams. The infection control department consists of 2.5 full-time employee nurse epidemiologists and a medical director who is an infectious disease specialist. RESULTS: The outbreak investigation illustrates principles of CQI and their relationship to epidemic surveillance through the use of applied statistical methods. CONCLUSIONS: The expanding role of hospital epidemiology is enhanced by applying CQI concepts to improving health care. The application of epidemiologic tools and principles to the problems of nosocomial infections is strongly connected to the CQI concept of using dependable data to improve processes.

Staphylococcus epidermidis ventriculitis treated with vancomycin and rifampin.

Two cases of ventriculitis with Staphylococcus epidermidis that failed on therapy with an antistaphylococcal penicillin are presented. Both infections responded to a combination of intravenous and intraventricular vancomycin and rifampin. Vancomycin and rifampin represent an important antibiotic regimen for the management of resistant infections of the central nervous system, especially with those due to S. epidermidis or methicillin-resistant Staphylococcus aureus.

Norwegian scabies in a patient with acquired immune deficiency syndrome.

A rare, severe form of scabies called Norwegian or keratotic scabies is described in a patient with acquired immune deficiency syndrome (AIDS). This is the first known description of this disease in an AIDS patient. The occurrence of secondary staphylococcal sepsis illustrates the importance of early correct diagnosis and treatment. Cutaneous hydration followed by aggressive application of gamma benzene hexachloride was safe and effective.

Cutaneous mucormycosis in a heart transplant patient.

We present the first case of cutaneous mucormycosis reported in a patient who had undergone a heart transplant operation. This appeared to be a localized infection without a predisposing local factor such as a surgical adhesive and without evidence of dissemination. Prompt treatment with intravenous amphotericin B resulted in an apparent cure.

Magnetic phase diagram of layered cobalt dioxide LixCoO2.

The magnetism of LixCoO2 (LCO), which has a similar structure to NaxCoO2 (NCO), has been investigated by muon-spin spectroscopy and susceptibility measurements using samples with x=0.1-1 prepared by an electrochemical reaction. In the x range below 0.75, LCO was found to be Pauli paramagnetic down to 1.8 K, suggesting an intermediate- or weak-coupling regime, although disordered local moments, with volume fractions below approximately 20%, appear at low T for LCO with x > or = 0.5. The phase diagram and interactions of LCO are thus strikingly different from NCO, while the differences cannot be explained simply by structural differences between the two systems.

Static magnetic order in metallic K0.49CoO2.

By means of muon-spin spectroscopy, we have found that K0.49CoO2 crystals undergo successive magnetic transitions from a high-T paramagnetic state to a magnetic ordered state below 60 K and then to a second ordered state below 16 K, even though K0.49CoO2 is metallic at least down to 4 K. An isotropic magnetic behavior and wide internal-field distributions suggest the formation of a commensurate helical spin density wave (SDW) state below 16 K, while a linear SDW state is likely to exist above 16 K. It was also found that exhibits a further transition at 150 K presumably due to a change in the spin state of the Co ions. Since the dependence of the internal-field below 60 K was similar to that for Na0.5CoO2, this suggests that magnetic order is more strongly affected by the Co valence than by the interlayer distance or interaction and/or the charge ordering.

Evidence of two dimensionality in quasi-one-dimensional cobalt oxides.

The quasi-one-dimensional (Q1D) cobalt oxides A(N + 2)Co(n + 1)O(3n + 3) (A = Ca, Sr, and Ba, n = 1 - infinity) were investigated by muon-spin spectroscopy under applied pressures of up to 1.1 GPa. The relationship between the onset Néel temperature T(on)(N) and the interchain distance (d(ic)), which increases monotonically with n, is well fitted by the formula T(N)/T(N,0) = (1 - d(ic)/d(ic,o)(beta), here for T(on)(N) approximately 100 K for Ca(3)Co(2)O(6) (n = 1) and approximately 15 for BaCoCoO(3) (n = infinity at ambient P. The T(on)(N) - d(ic) curve also predicts a large dependence of Y(N) for the compounds with n > or = 5, i.e., in the vicinity of , while the compounds show only a very small effect. Indeed, our high-pressure mu(+) results show that of BaCoO(3) is enhanced by with a slope of 2.2 K(Gpa), whereas no detectable changes by P for both Ca(3)Co(2)O(6) and Sr(4)Co(3)O(9) (n = 2). This clearly confirms the role of the 2D-antiferromagnetic interaction on T(on)(N) in the Q1D cobalt oxides.

Anaerobic microbiology in the NASA space program.

After briefly reviewing the earlier methods used to monitor the microbial load of returned lunar material, the author reports the more accurate research on the ability of terrestrial organisms to grow under simulated Martian environments. The possible importance of anaerobic microbiology can readily be seen because of the low level of O2 found on Mars. The question of whether any of the experiments on board the Viking landers show any indication of life on Mars is discussed in detail.

A disposable anaerobic system designed for field and laboratory use.

A disposable anaerobic system which is characterized by its light weight and its compactness is described. The system consists of a multilayer plastic bag with a unique sealing device. A collapsible impregnated cardboard container is fitted with a catalyst and holders for a disposable hydrogen generator and an anaerobic indicator. The catalyst is active at room temperature and requires no heat activation. This system, which lends itself readily to compact storage, quick assembly, and ease of operation, is disposable after use.

Safe Self-contained Carbon Dioxide-Hydrogen Anaerobic System.

An anaerobic system is described which allows the microbiologist or hospital technician ease of operation not previously possible with other systems. Gas cylinders, vacuum pumps, valves, and gauges have been eliminated. A new anaerobic lid was developed that is fitted only with a snap-in rubber gasket, a double stainless-steel gauze flash arrestor, and a catalyst holder. The holder contains a palladium pellet catalyst which is active at room temperature and requires no heat for activation. This system was made specifically for use with a disposable hydrogen-carbon dioxide generator and a disposable methylene blue anaerobic indicator. In addition to ease of operation, this jar incorporates unique safety features which eliminate the possibility of a laboratory explosion. An oxygen-free atmosphere composed primarily of nitrogen and carbon dioxide was quickly achieved within the jar to insure maximal growth.

Isolation and characterization of omnitherms and facultative anaerobes from Cape Canaveral soil samples.

In a bacterial population profile of interplanetary spacecraft environments based upon temperature and oxygen requirements, several isolates demonstrated the ability to grow over a temperature range from 3 degrees C to 55 degrees C, and most grew aerobically and anaerobically. Because of the adaptability of these organisms, they may be of significance to planetary contamination. To verify that these were actively growing in this range of temperatures, they were streaked onto trypticase soy agar (TSA) and incubated at the extreme temperatures (3 degrees C and 55 degrees C). Isolated colonies were transferred to fresh TSA and immediately incubated at the opposite extreme temperatures. Almost all of the isolates grew quite well at both temperatures. Because these have been subcultured numerous times and still possess the ability to grow over a broad temperature range, this appears to be a stable characteristic. Many of these isolates possess the ability to grow anaerobically at 3, 32 and 55 degrees C. All of these organisms are sporeformers, and data are presented concerning their heat resistance and biochemical activity.

Posttraumatic Pasteurella multocida meningitis.

The patient described was immunologically compromised by multisystem trauma. Pasteurella multocida was isolated from the respiratory tract and subsequently from the cerebrospinal fluid; direct spread apparently occurred by way of a basilar skull fracture. Sepsis was absent. He was successfully treated but subsequently had hydrocephalus, which has not previously been reported to occur after P multocida meningitis. Because of the opportunistic nature of this infrequent human commensal and the significant morbidity and mortality associated with it, we believe that isolation of Pasteurella multocida from the respiratory tract justifies treatment, especially in the compromised host.

Evaluation of a new microquantity blood collector.

A new device for collecting small amounts of blood from laboratory animals offer distinct advantages over standard syringes during the collection of serum or plasma.

Disseminated coccidioidomycosis in a heart transplant recipient.

A cardiac transplant patient developed disseminated coccidioidomycosis shortly after transplantation and institution of immunosuppressive therapy. The patient was maintained on intravenous and intrathecal amphotericin B for 19 months, but when therapy was discontinued, the disease relapsed and he died. At autopsy the cardiac allograft was without signs of rejection, but the patient had coccidioidomycotic lesions in multiple organs. There is an increasing number of reports of disseminated coccidioidomycosis in immunocompromised patients, especially those who receive steroids or immunosuppressive therapy. Coccidioidomycosis may represent a severe complication in the transplant patient.

Influence of impurities on short range electron transport in GaAs.

The influence of Cr impurities on muonium atom formation in GaAs has been studied using muon spin relaxation techniques with alternating electric fields. The results suggest that electron transport to and capture by the muon is suppressed by capture/scattering on intervening Cr centers. The length scale involved is estimated to be about 3x10(-6) cm. This offers an opportunity to study electron transport to positive centers in semiconductors on a microscopic scale.