Hospital Reservoirs of Multidrug Resistant Acinetobacter Species-The Elephant in the Room!

Environmental contamination is estimated to contribute to up to 20% of all hospital acquired infections. Acinetobacter baumannii is an example of one the most prevalent opportunistic pathogens causing severe and persistent infections in immunocompromised patients. It has proven ability to form biofilms, has significant associated multi-drug resistance and is able to transfer mobile genetic elements to other clinically relevant pathogens. All of these factors point to a definite utility of A. baumannii as an indicator organism for effectiveness of decontamination regimens as well as environmental screening. There is an increased cost, both financial and clinical, associated with multi drug resistant organisms, carbapenem resistant A. baumannii. With a dearth of new antimicrobials in development, now is the time to radically transform and lead the introduction of scientifically based environmental screening and microbiological verified decontamination to control the dissemination of further resistance.

Observation of photo-induced plasmon-phonon coupling in PbTe via ultrafast x-ray scattering.

We report the observation of photo-induced plasmon-phonon coupled modes in the group IV-VI semiconductor PbTe using ultrafast x-ray diffuse scattering at the Linac Coherent Light Source. We measure the near-zone-center excited-state dispersion of the heavily screened longitudinal optical (LO) phonon branch as extracted from differential changes in x-ray diffuse scattering intensity following above bandgap photoexcitation. We suggest that upon photoexcitation, the LO phonon-plasmon coupled (LOPC) modes themselves become coupled to longitudinal acoustic modes that drive electron band shifts via acoustic deformation potentials and possibly to low-energy single-particle excitations within the plasma and that these couplings give rise to displacement-correlations that oscillate in time with a period given effectively by the heavily screened LOPC frequency.

Coping with the COVID-19 crisis: an overview of service adaptation and challenges encountered by a rural Psychiatry of Later Life (POLL) team.

The COVID-19 pandemic has posed many challenges in maintaining standards of care and treatment for patients while managing the increased anxieties of patients, carers and the public in general. This paper highlights several clinical, administrative, medicolegal and IT implications of COVID-19 on the delivery of mental healthcare to an elderly vulnerable patient cohort due to recommended social distancing measures. Our Psychiatry of Later Life team has adapted to this by restricting face-to-face consultation, while continuing to provide telephone support. We have modified our documentation standard and have improved some aspects of our team working by facilitating flexible working arrangement and relevant training for staff as well as by embracing new technology. Notwithstanding the challenges therefore, this exceptional time has also opened avenues for new and innovative opportunities that can be further explored even when the current crisis eventually passes.

Carbapenemase screening in an Irish tertiary referral hospital: Best practice, or can we do better?

BACKGROUND: Carbapenems are a family of end line antibiotics with increasing levels of resistance that are a cause for concern. AIM: To ascertain whether the CPE screening programme employed in an acute tertiary hospital is fit for purpose. METHOD: We outlined the current working algorithm employed using a universal screening programme over a 26-month screening period. Rectal swabs are cultured on arrival. Those with suspicious growth are further investigated using NG-Carba 5 lateral flow tests and Vitek 2.0 sensitivity cards. These practices were compared with NHS guidelines. FINDINGS & CONCLUSIONS: In all, 53 true positives were detected from 45 patients since the screening was implemented in early 2018 (46 OXA-48, 6 KPC, 1 NDM). As the rate of screening increased, the number of positive screens decreased over time. There were a lot of similarities between the HSE guidelines and the published NHS CPE toolkit. It was evident that there is no standard practice being employed across all hospitals. Comparing the MUH to national guidelines it appears to be quicker and more effective with universal screening in place at reducing the potential contacts and identifying carriers. Cost analysis indicates that the need to confirm all positive strains in a reference lab is costly, unnecessary and time consuming. There are adequate confirmatory tests available in-house for routine positive screens. It was concluded that infection prevention and control are key to identifying and controlling possible outbreaks in a hospital setting.

Factors associated with the effectiveness and reach of NHS stop smoking services for pregnant women in England.

BACKGROUND: The UK National Health Service provides Stop Smoking Services for pregnant women (SSSP) but there is a lack of evidence concerning how these are best organised. This study investigates influences on services' effectiveness and also on their propensity to engage pregnant smokers with support in stopping smoking. METHODS: Survey data collected from 121/141 (86%) of SSSP were augmented with data from Hospital Episode Statistics and the 2011 UK National Census. 'Reach' or propensity to engage smokers with support was defined as the percentage of pregnant smokers setting a quit date with SSSP support, and 'Effectiveness' as the percentage of women who set a quit date who also reported abstinence at four weeks later. A bivariate (i.e. two outcome variable) response Markov Chain Monte Carlo model was used to identify service-level factors associated with the Reach and Effectiveness of SSSP. RESULTS: Beta coefficients represent a percentage change in Reach and Effectiveness by the covariate. Providing the majority of one-to-one contacts in a clinic rather than at home increased both Reach (%) (ß: 6.97, 95% CI: 3.34, 10.60) and Effectiveness (%) (ß: 7.37, 95% CI: 3.03, 11.70). Reach of SSSP was also increased when the population served was more deprived (ß for increase in Reach with a one unit increase in IMD score: 0.55, 95% CI: 0.25, 0.85), had a lower proportion of people with dependent children (ß: -2.52, 95% CI: -3.82, -1.22), and a lower proportion of people in managerial or professional occupations (ß: -0.31, 95% CI: -0.59, -0.03). The Effectiveness of SSSP was decreased in those areas that had a greater percentage of people >16 years with no educational qualifications (ß: -0.51, 95% CI: -0.95, -0.07). CONCLUSIONS: To engage pregnant smokers and to encourage them to quit, it may be more efficient for SSSP support to be focussed around clinics, rather than women's homes. Reach of SSSP is inversely associated with disadvantage and efforts should be made to contact these women as they are less likely to achieve abstinence in the short and longer term.

The origin of incipient ferroelectricity in lead telluride.

The interactions between electrons and lattice vibrations are fundamental to materials behaviour. In the case of group IV-VI, V and related materials, these interactions are strong, and the materials exist near electronic and structural phase transitions. The prototypical example is PbTe whose incipient ferroelectric behaviour has been recently associated with large phonon anharmonicity and thermoelectricity. Here we show that it is primarily electron-phonon coupling involving electron states near the band edges that leads to the ferroelectric instability in PbTe. Using a combination of nonequilibrium lattice dynamics measurements and first principles calculations, we find that photoexcitation reduces the Peierls-like electronic instability and reinforces the paraelectric state. This weakens the long-range forces along the cubic direction tied to resonant bonding and low lattice thermal conductivity. Our results demonstrate how free-electron-laser-based ultrafast X-ray scattering can be utilized to shed light on the microscopic mechanisms that determine materials properties.

Optical probing of ultrafast electronic decay in Bi and Sb with slow phonons.

Illumination with laser sources leads to the creation of excited electronic states of particular symmetries, which can drive isosymmetric vibrations. Here, we use a combination of ultrafast stimulated and cw spontaneous Raman scattering to determine the lifetime of A(1g) and E(g) electronic coherences in Bi and Sb. Our results both shed new light on the mechanisms of coherent phonon generation and represent a novel way to probe extremely fast electron decoherence rates. The E(g) state, resulting from an unequal distribution of carriers in three equivalent band regions, is extremely short lived. Consistent with theory, the lifetime of its associated driving force reaches values as small as 2 (6) fs for Bi (Sb) at 300 K.

Non-equilibrium phonon dynamics studied by grazing-incidence femtosecond X-ray crystallography.

The timescales for structural changes in a single crystal of bismuth after excitation with an intense near-infrared laser pulse are studied with femtosecond pump-probe X-ray diffraction. Changes in the intensity and reciprocal-lattice vector of several reflections give quantitative information on the structure factor and lattice strain as a function of time, with a resolution of 200 fs. The results indicate that the majority of excess carrier energy that remains near the surface is transferred to vibrational modes on a timescale of about 10 ps, and that the resultant increase in the variance of the atomic positions at these times is consistent with the overall magnitude of lattice strain that develops.

Observation of insulating nanoislands in ferromagnetic GaMnAs.

Resonant Raman data on ferromagnetic GaMnAs reveal the existence of a new kind of defect: insulating nanoislands consisting of substitutional MnGa acceptors surrounded by interstitial MnI donors. As indicated by the observation of a sharp 1S3/2-->2S3/2 Raman transition at approximately 703 cm(-1), the acceptor-bound holes inside the islands are isolated from the metallic surroundings. Instead, Mn-bound excitons do couple to the ferromagnetic environment, as shown by the presence of associated Raman magnon side bands. This leads to an estimate of 5-10 nm for the nanoisland radius. The islands disappear after annealing due to the removal of the MnI ions.

Directly observing squeezed phonon states with femtosecond x-ray diffraction.

Squeezed states are quantum states of a harmonic oscillator in which the variance of two conjugate variables each oscillate out of phase. Ultrafast optical excitation of crystals can create squeezed phonon states, where the variance of the atomic displacements oscillates due to a sudden change in the interatomic bonding strength. With femtosecond x-ray diffraction we measure squeezing oscillations in bismuth and conclude that they are consistent with a model in which electronic excitation softens all phonon modes by a constant scaling factor.

Ultrafast bond softening in bismuth: mapping a solid's interatomic potential with X-rays.

Intense femtosecond laser excitation can produce transient states of matter that would otherwise be inaccessible to laboratory investigation. At high excitation densities, the interatomic forces that bind solids and determine many of their properties can be substantially altered. Here, we present the detailed mapping of the carrier density-dependent interatomic potential of bismuth approaching a solid-solid phase transition. Our experiments combine stroboscopic techniques that use a high-brightness linear electron accelerator-based x-ray source with pulse-by-pulse timing reconstruction for femtosecond resolution, allowing quantitative characterization of the interatomic potential energy surface of the highly excited solid.

First-principles calculation of alloy scattering in Ge(x)Si(1-x).

First-principles electronic structure methods are used to find the rates of intravalley and intervalley n-type carrier scattering due to alloy disorder in Si(1-x)Ge(x) alloys. The required alloy scattering matrix elements are calculated from the energy splitting of nearly degenerate Bloch states which arises when one average host atom is replaced by a Ge or Si atom in supercells containing up to 128 atoms. Scattering parameters for all relevant Delta and L intravalley and intervalley alloy scattering are calculated. Atomic relaxation is found to have a substantial effect on the scattering parameters. f-type intervalley scattering between Delta valleys is found to be comparable to other scattering channels. The n-type carrier mobility, calculated from the scattering rate using the Boltzmann transport equation in the relaxation time approximation, is in excellent agreement with experiments on bulk, unstrained alloys.

Transient strain driven by a dense electron-hole plasma.

We measure transient strain in ultrafast laser-excited Ge by time-resolved x-ray anomalous transmission. The development of the coherent strain pulse is dominated by rapid ambipolar diffusion. This pulse extends considerably longer than the laser penetration depth because the plasma initially propagates faster than the acoustic modes. X-ray diffraction simulations are in agreement with the observed dynamics.

Lithium use in octogenarians.

OBJECTIVES: To assess the tolerability and side-effect profile of lithium use in a group of octogenarians attending a specialized lithium clinic. METHODS: This is a cross-sectional study looking at all patients of eighty years and over attending a lithium clinic. Charts were examined to assess renal function, thyroid function and level of side-effects during their course of lithium treatment in order to assess the tolerability of this medication in octogenarians. RESULTS: Twelve patients of 80 years and over (with an average age of 83.6 years) were taking lithium for an average period of 53.7 months. They had a mean serum level of 0.42 mmol/l. No patient had to discontinue lithium therapy because of side-effects, even though some patients did develop transient abnormalities of renal function. One patient developed diabetes insipidus. One female patient developed hypothyroidism. CONCLUSIONS: Lithium was well tolerated and was administered safely to this cohort of octogenarians. Monitoring of serum lithium levels and kidney and thyroid function should preferably be done in the setting of a specialized lithium clinic.

Discontinuation of lithium augmentation in an elderly cohort.

OBJECTIVES: To observe the effects of gradual discontinuation of lithium augmentation therapy in a group of patients over the age of 65 years and to measure the rate of relapse and to identify any factors which would predict relapse. METHODS: This was a naturalistic study involving 21 patients who were on lithium augmentation and whose lithium was discontinued for a variety of clinical reasons. In most cases lithium was tapered and discontinued over a period of 2-12 weeks. Demographic and other variables were collected at baseline and compared between those who remained well and those that subsequently relapsed. RESULTS: Eleven patients (52.4%) relapsed following discontinuation of lithium augmentation. Those who relapsed had been on lithium for significantly longer than those who remained well off lithium (p = 0.007). There was a trend towards more hospital admissions in the relapse group (p = 0.062). CONCLUSIONS: When lithium augmentation therapy is discontinued in elderly depressives over half of these patients relapse. A longer duration of prediscontinuation lithium treatment and more hospital admissions appear to be associated with increased risk of relapse.

Detection of benzodiazepine abuse in opiate addicts.

There is an increasing problem with benzodiazepine co-abuse in the opiate dependent population of Dublin. The importance of early detection of this co-abuse is essential as there is an increased risk of dangerous injecting practices such as sharing of needles and criminality in those who co-abuse benzodiazepines and opiates. This study was carried out in the National Drug Treatment Centre, Dublin. It aims to describe the current difficulties in identifying the co-abuse of short acting benzodiazepines including flunitrazepam in a cohort of opiate dependent patients. Using a sample of those attending the clinic it was discovered that standard methods of urinalysis failed to identify 10% of co-abuse. For those patients whose abuse of flunitrazepam is undetected on screening, clinical interventions which aim to minimise the consequence of the co-abuse and reverse the chaotic drug using patterns fail to be put in place at the earliest possible time.