Stark and Zeeman effect in the [18.6]3.5 - X(1)4.5 transition of uranium monofluoride, UF.

High resolution spectra of the 0-0 band of the [18.6]3.5 - X(1)4.5 transition of uranium monofluoride, UF, obtained using a laser ablation spectrometer, showed a perturbation in the upper state. Examination of the Stark and Zeeman effects yielded permanent electric dipole moments of 2.01 and 1.88 D and magnetic g-factors of 3.28 and 3.26 for the ground and excited states, respectively. Both the dipole moment and g-factor of the ground state are in good agreement with ab initio calculations [I. O. Antonov and M. C. Heaven, J. Phys. Chem. A 117, 9684 (2013)]. The Zeeman effect results confirm that the ground state arises primarily from the U(+)(5f (3)7s(2 4)I(4.5))F(-) configuration and suggest several possible configurations for the upper state.

Health Evaluation of Experimental Laboratory Mice.

Good science and good animal care go hand in hand. A sick or distressed animal does not produce the reliable results that a healthy and unstressed animal produces. This unit describes the essentials of assessing mouse health, colony health surveillance, common conditions, and determination of appropriate endpoints. Understanding the health and well-being of the mice used in research enables the investigator to optimize research results and animal care.

Confirmed Candida albicans endogenous fungal endophthalmitis in a patient with chronic candidiasis.

We present a case of a confirmed Candida albicans endogenous endophthalmitis in a 35-year-old diabetic white female patient with a long standing history of severe chronic vaginal C. albicans infection. The patient had recently undergone ureteric stenting and received intravenous broad-spectrum antibiotics for renal stones complicated by urinary sepsis. Pan-fungal polymerase chain reaction (PCR) analysis of vitreous aspirate confirmed the presence of C. albicans. Samples showed no microbial growth.

Treatment of Chlamydia trachomatis with a small molecule inhibitor of the Yersinia type III secretion system disrupts progression of the chlamydial developmental cycle.

The obligate intracellular bacterium Chlamydia trachomatis possesses a biphasic developmental cycle that is manifested by differentiation of infectious, metabolically inert elementary bodies (EBs) to larger, metabolically active reticulate bodies (RBs). The cycle is completed by asynchronous differentiation of dividing RBs back to a population of dormant EBs that can initiate further rounds of infection upon lysis of the host cell. Chlamydiae express a type III secretion system (T3SS) that is presumably employed to establish and maintain the permissive intracellular niche by secretion of anti-host proteins. We hypothesize that T3SS activity is essential for chlamydial development and pathogenesis. However, the lack of a genetic system has confounded efforts to establish any role of the T3SS. We therefore employed the small molecule Yersinia T3SS inhibitor N'-(3,5-dibromo-2-hydroxybenzylidene)-4-nitrobenzohydrazide, designated compound 1 (C1), to examine the interdependence of the chlamydial T3SS and development. C1 treatment inhibited C. trachomatis but not T4SS-expressing Coxiella burnetii development in a dose-dependent manner. Although chlamydiae remained viable and metabolically active, they failed to divide significantly and RB to EB differentiation was inhibited. These effects occurred in the absence of host cell cytotoxicity and were reversible by washing out C1. We further demonstrate that secretion of T3S substrates is perturbed in C1-treated chlamydial cultures. We have therefore provided evidence that C1 can inhibit C. trachomatis development and T3SS activity and present a model in which progression of the C. trachomatis developmental cycle requires a fully functional T3SS.

Multiple scattering by random configurations of circular cylinders: second-order corrections for the effective wavenumber.

A formula for the effective wavenumber in a dilute random array of identical scatterers in two dimensions is derived, based on Lax's quasicrystalline approximation. This formula replaces a widely-used expression due to Twersky, which is shown to be based on an inappropriate choice of pair-correlation function.

Isotope effects and Born-Oppenheimer breakdown in excited singlet states of the lithium dimer.

Observation of infrared electronic transitions involving the 1 (1)Deltag state of 7Li2 has instigated an investigation of Born-Oppenheimer breakdown in four singlet electronic states correlating with (2s+2s), (2s+2p), and (2p+2p) lithium atoms. The 1 (1)Deltag state, which correlates at long range with (2p+2p) atoms, has been observed in emission from the (5p) (1)Piu Rydberg state and in 1 (1)Deltag-B (1)Piu bands, in both instances following optical-optical double-resonance excitation. The latter transition was observed previously for the lighter isotopomer, 6Li2 [C. Linton, F. Martin, P. Crozet, A. J. Ross, and R. Bacis, J. Mol. Spectrosc. 158, 445 (1993)]. By analyzing multiple-isotopomer data for several electronic systems simultaneously, we have determined the electronic isotope shifts and the leading vibrational and/or rotational Born-Oppenheimer breakdown terms for the X (1)Sigmag+, A (1)Sigmau+, B (1)Piu, and 1 (1)Deltag states of the lithium dimer. This paper also reports Fourier transform measurements of the B-X absorption spectra of 6Li2 and 7Li2, which were required to better define the bottom portion of the B (1)Piu state potential.

Using thiamine to reduce post-ECT confusion.

Cognitive side-effects are commonly seen following electroconvulsive therapy which convey no therapeutic benefit but are troublesome to both patient and clinician. Various efforts have been made in the past to minimize these symptoms. Although modification of technical parameters related to ECT administration has led to some limited improvement in this regard, attention is now being increasingly focussed on pharmacological approaches. A number of agents have been explored in this context, however, as far as we are aware, the use of thiamine has not yet been investigated. We present three cases of elderly patients undergoing ECT for major depression in whom thiamine administration was associated with beneficial effects on post-ECT confusion. We review the evidence suggesting that thiamine deficiency may be implicated in the confusional state following ECT and recommend that consideration be given to its use in preventing and treating this problematic side-effect, especially in elderly patients.

Carriage of antibiotic-resistant bacteria by healthy children.

The frequency of carriage of antibiotic-resistant bacteria in healthy 7- and 8-year-old children in Bristol was studied. Children born in Avon between 1 April 1991 and 31 December 1992, attending the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC) 7 year follow-up clinic, formed the study population. Carriage was estimated using mouth and stool samples. None of 105 children on whom information was available had received tetracycline, chloramphenicol, ciprofloxacin or an extended-spectrum cephalosporin in the previous year. Staphylococcus aureus was isolated from mouthwashes from 200 (37.1%) of 539 children sampled. Six (3%) of the isolates were resistant to chloramphenicol or tetracycline and four (2%) were methicillin resistant. Haemophilus spp. were isolated from 369 (72%) of 513 samples and 63 (17%) were ampicillin resistant, 49 (13.3%) were erythromycin resistant and seven (1.9%) were tetracycline resistant. Branhamella catarrhalis was isolated from 333 (74%) of 450 samples. Twenty-eight (8.4%) were erythromycin resistant and 14 (4.2%) strains were tetracycline resistant. Group A beta-haemolytic streptococci were isolated from 17 of 507 children sampled. One (5.9%) was tetracycline resistant. Stool samples were returned from 335 (62%) of 539 children from whom they were requested. Eleven per cent of samples yielded Gram-negative bacilli with high-level resistance to chloramphenicol, which was frequently linked to resistance to ampicillin, spectinomycin and streptomycin. Isolates demonstrating resistance to the third-generation cephalosporin ceftazidime were recovered from 17 subjects (3.2%). Six (35%) of 17 isolates possessed extended-spectrum beta-lactamases. Healthy children carry bacteria resistant to antibiotics to which children are not usually exposed. Resistance to ceftazidime, chloramphenicol and tetracycline may be co-selected by exposure to other antibiotics used in children or may be acquired from family members, pets, other children or food. These results suggest that antibiotic-resistant bacteria are widely disseminated and may be acquired by children before exposure to specific selection pressure.

High-Resolution Laser Spectroscopy of YbCl: The B(2)Sigma(+)-X(2)Sigma(+) Transition.

High-resolution laser excitation spectra have been obtained for the 0-0, 1-1, and 0-1 bands of the B(2)Sigma(+)-X(2)Sigma(+) transition of YbCl and a rotational analysis has been performed on the (174)Yb(35)Cl and (172)Yb(35)Cl isotopomers. Comparison of the spin-rotation constant, gamma, for the B(2)Sigma(+) state with the lambda-doubling constant of the A(2)Pi(1/2) state (1) shows that the two excited states form a unique perturber pair arising from the 6psigma and 6ppi orbitals centered on the Yb(+) ion. The principal results for the B(2)Sigma(+) state are B(e)=0.097552(5) cm(-1), R(e)=2.43623(6) Å, gamma(e)=-2.1655(6)x10(-4) cm(-1), and DeltaG(1/2)=313.111(2) cm(-1). Copyright 2001 Academic Press.

Travel-induced psychosis in the elderly.

We present three cases of travel-induced psychosis in an elderly population. The clinical presentations are described with a review of the literature.

Rationalised prescribing for community acquired pneumonia: a closed loop audit.

AIMS: To audit the management of community acquired pneumonia before and after the introduction of a protocol. To determine the aetiology of pneumonia using routine investigations and polymerase chain reaction (PCR). METHODS: Retrospective and prospective audit following the introduction of a management protocol. Prospective cases were investigated routinely and with PCR on blood and nasopharyngeal aspirate. RESULTS: There was a significant increase in rational prescribing following introduction of the protocol with 75% of children receiving intravenous penicillin or erythromycin compared with 26% beforehand. Of 89 children in the prospective group, 51 microbiological diagnoses were achieved in 48 children. Seven children had Streptococcus pneumoniae infection, 14 had Mycoplasma infection, six had pertussis, and one had Chlamydia pneumoniae infection. Twenty three children had a viral cause of which respiratory syncytial virus was commonest. CONCLUSIONS: Introduction of the protocol led to improved prescribing. PCR increased the diagnostic yield and the results support the management protocol.

High-Resolution Laser Spectroscopy of YbCl: The A(2)Pi-X(2)Sigma(+) Transition.

The A(2)Pi-X(2)Sigma(+) transition of (174)Yb(35)Cl and (172)Yb(35)Cl has been rotationally analyzed for the first time. Doppler-limited laser excitation spectroscopy with selective detection of fluorescence was used to obtain spectra of the 0-0 and 1-0 bands with a measurement accuracy of approximately 0.0035 cm(-1). Resolved fluorescence was used to record the 0-1, 0-2, and 0-3 bands and to unequivocally assign the rotational numbering, N, to the laser excitation spectra. In total, over 1300 line positions have been measured and assigned for each of the two isotopomers and employed in least-squares fits of molecular parameters. The principal results for the A(2)Pi state are A(e) = 1491.494(2) cm(-1) and R(e) = 2.4433(1) Å, and for the X(2)Sigma(+) state, R(e) = 2.4883(2) Å and gamma(e) = 4.59(2) x 10(-3) cm(-1). The interaction between the X(2)Sigma(+) and A(2)Pi states has been investigated and is shown to be the main contributor to the spin-rotation splitting in the ground state. Copyright 2000 Academic Press.

The High-Lying Vibrational Levels and Dissociation Energy of the a3Sigma+u State of 7Li2.

Perturbation-facilitated optical-optical double resonance (PFOODR) has been used to access the 2(3)Pig state of 7Li2 via the excitation scheme using two single-mode tunable lasers. The selected () mixed level provides a gateway through which the triplet manifold can be accessed. Fluorescence from single rovibrational levels of 2(3)Pig to the state was detected at high resolution using a Fourier transform spectrometer. Transitions to v = 0-9 in the state were observed, covering the potential well almost to the dissociation limit. The data were analyzed using a near dissociation expansion (NDE) technique and the resulting vibrational and rotational parameters were used to calculate a new RKR potential curve which reproduced the observed energy levels to within a rms error of 0.02 cm-1. The following parameters were obtained for the state: D0 = 301.829 +/- 0.015 cm-1, De = 333.69 +/- 0.10 cm-1, Te = 8183.12 +/- 0.12 cm-1. Copyright 1999 Academic Press.

Use of a modified Robbins device to directly compare the adhesion of Staphylococcus epidermidis RP62A to surfaces.

Staphylococcus epidermidis is a frequent cause of infection associated with the use of biomedical devices. Flow cell studies of the interaction between bacteria and surfaces do not generally allow direct comparison of different materials using the same bacterial suspension. The use of a modified Robbins Device (MRD) to compare the adhesion to different surfaces of Staph. epidermidis RP62A grown in continuous culture was investigated. Adhesion to glass was compared with siliconized glass, plasma-conditioned glass, titanium, stainless steel and Teflon. Attachment to siliconized glass was also compared with glass under differing ionic strength, and divalent cation concentrations. Both the differences in numbers adhering and changes in adhesion (slope) through the MRD were compared. There was a trend towards higher numbers adhering to the discs at the in-flow end of the MRD than at the outflow end, probably reflecting depletion of adherent bacteria in the interacting stream. Adhesion of Staph. epidermidis RP62A to siliconized glass and Teflon was reduced when compared to glass with increasing flow rates. Adhesion to stainless steel was not affected by flow rate and titanium gave a different slope of adhesion through the MRD when compared with glass, suggesting an interaction with different sub-populations within the interacting stream. Differences between siliconized glass and glass at flow rates of 300 ml h-1 were abolished by the addition of calcium or EDTA and reduced by the addition of magnesium. Increasing ionic strength reduced the statistical significance of the differences between glass and siliconized glass. Pre-conditioning of glass with pooled human plasma reduced adhesion compared with untreated glass and again gave a different slope to glass. The MRD linked to a chemostat can be used to compare directly bacterial adhesion to potential biomaterials. Variable depletion of the interacting stream should be taken into account in the interpretation of results. Divalent cation concentration, substrate properties and flow rate were important determinants of the comparative adhesion of Staph. epidermidis RP62A to surfaces.

On the 5d 1Pig --> 2 (1)Sigma+u and 5d 1Pig --> C 1Piu Fluorescence in 7Li2.

Following excitation of the 5d 1Pig Rydberg state of 7Li2 by optical-optical double resonance, fluorescence has been observed in the infrared region to the 2 (1)Sigma+u and C 1Piu states. Analysis of high-resolution Fourier transform spectra yields term energies and rotational constants of the lowest seven vibrational levels of the inner well of the 2 (1)Sigma+u "double minimum" state. The equilibrium term value and dissociation energy have been determined to be Te = 30101.45 +/- 0.12 cm-1 and De = 5621.3 +/- 0.2 cm-1. The v = 0 and 1 levels of the C 1Piu state have been analyzed, resulting in new values of Te = 30551.0 +/- 0.1 cm-1 and De = 7773.3 +/- 0.2 cm-1. Copyright 1998 Academic Press.

Detection of bacteraemia in patients with fever and neutropenia using 16S rRNA gene amplification by polymerase chain reaction.

Episodes of fever and neutropenia are common complications of treatment for cancer. The use of prophylactic and early empirical antibiotics has reduced mortality but decreases the sensitivity of diagnostic tests based on culture. The aim of this study was to determine the potential of a broad diagnostic approach (eubacterial) based on 16S rRNA gene amplification and sequencing to augment cultural methods of diagnosis of bacteraemia in patients with fever and neutropenia in a regional paediatric oncology centre. One hundred eleven patient-episodes of fever and neutropenia were evaluated during the study period, 17 of which were associated with positive blood cultures, as follows: Staphylococcus epidermidis (n = 6 episodes), Enterococcus faecium (n = 2), Streptococcus sanguis (n = 3), Streptococcus mitis (n = 3), Staphylococcus aureus (n = 1), Micrococcus spp. (n = 1), and Stenotrophomonas maltophilia (n = 1). Eubacterial polymerase chain reaction (PCR) detected bacterial DNA in nine of 11 blood culture-positive episodes for which a sample was available for PCR; the species identified by sequence analysis were identical to those derived from the conventional identification of the cultured isolates. Bacterial DNA was detected in 20 episodes (21 bacterial sequences) associated with negative blood cultures, 18 of which occurred in patients who were receiving antibiotics at the time of sample collection. The species presumptively identified by partial 16S rRNA gene sequencing were as follows: Pseudomonas spp. (n = 6 episodes), Acinetobacter spp. (n =5 ); Escherichia spp. (n = 3); Moraxella spp. (n = 3); Staphylococcus spp. (n = 2); Neisseria spp. (n = 1); and Bacillus spp. (n = 1). The results of this study suggest that molecular techniques can augment cultural methods in the diagnosis of bacteraemia in patients who have been treated with antibiotics.