A multiconfigurational time-dependent Hartree-Fock method for excited electronic states. I. General formalism and application to open-shell states

The solution of the time-dependent Schrodinger equation for systems of interacting electrons is generally a prohibitive task, for which approximate methods are necessary. Popular approaches, such as the time-dependent Hartree-Fock (TDHF) approximation and time-dependent density functional theory (TDDFT), are essentially single-configurational schemes. TDHF is by construction incapable of fully accounting for the excited character of the electronic states involved in many physical processes of interest; TDDFT, although exact in principle, is limited by the currently available exchange-correlation functionals. On the other hand, multiconfigurational methods, such as the multiconfigurational time-dependent Hartree-Fock (MCTDHF) approach, provide an accurate description of the excited states and can be systematically improved. However, the computational cost becomes prohibitive as the number of degrees of freedom increases, and thus, at present, the MCTDHF method is only practical for few-electron systems. In this work, we propose an alternative approach which effectively establishes a compromise between efficiency and accuracy, by retaining the smallest possible number of configurations that catches the essential features of the electronic wavefunction. Based on a time-dependent variational principle, we derive the MCTDHF working equation for a multiconfigurational expansion with fixed coefficients and specialise to the case of general open-shell states, which are relevant for many physical processes of interest. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3600397]

Extension of general practice training from three to four years: experiences of a vocational training programme in Southern Ireland

The aim of this study was to evaluate the experiences of trainees taking part in an extended (four-year) general practice training programme introduced in the South Eastern region of the Republic of Ireland to replace the previous traditional (three-year) programme. In a qualitative design, eight homogeneous focus groups were held to determine the value of the additional year of training. The first cohort of trainees was interviewed towards the start and at the end of their fourth year. Trainees finishing the following year were also interviewed, as were graduates from the final three-year programme. GP trainers and the four members of the programme directing team comprised two further independent focus groups. Trainees reported that the integration of hospital posts and general practice attachments over the four years was particularly beneficial. The exposure to a variety of different general practices and the opportunity to take part in specialty clinics were considered extremely useful. The fourth year of training was felt to be less pressurised than previous years. Professional and personal development was enhanced; improved readiness to practise and confidence were noted. Perceived disadvantages of extended training included a lack of acknowledgment for doctors in their fourth year and excessive emphasis placed on research during the final year of training. The addition of an extra year of vocational training improves professional and personal development and changes the learning experience for doctors. Doctors felt more confident and ready to enter independent practice at the end of the fourth year of training.

A PEPTIDE FROM THE CAUDAL NEUROSECRETORY-SYSTEM OF THE DOGFISH SCYLIORHINUS-CANICULA THAT IS STRUCTURALLY RELATED TO UROTENSIN-I

Using reversed-phase HPLC in combination with a radioimmunoassay for ovine corticotropin-releasing hormone (CRH), a peptide with CRH-like immunoreactivity was isolated in pure form from an extract of the caudal spinal cord region of the spotted dogfish, Scyliorhinus canicula. The primary structure of the peptide was established as Pro-Ala-Glu-Thr-Pro-Asn-Ser-Leu-Asp-Leu(10)-Thr-Phe-His-Leu-Leu-Arg-Glu-Met-Ile-Glu(20)-Ile-Ala-Lys-His-Glu-Asn-Gln-Gln-Met-Gln(30)-Ala-Asp-Ser-Asn-Arg-Arg-Ile-Met-Asp-Thr(40)-Ile . NH2. This amino acid sequence shows moderate structural similarity to Catostomus urotensin I (51%) and to human CRH (56%). The data provide, therefore, chemical evidence to support the conclusions of earlier immunohistochemical studies that the diffuse caudal neurosecretory system of elasmobranchs produces a peptide that is immunochemically related to teleost urotensin I peptides. However, the primary structure of urotensin I has been poorly conserved during evolution. (C) 1995 Academic Press, Inc.

A randomised study of two training programmes for general practitioners in the techniques of shoulder injection

Training on patients in addition to conventional mannequins increased GPs shoulder injection activity and their level of confidence.Hospital injection clinicsa may provide a suitable setting in which to train GPs interested in developing their shoulder joint injection skills

Modelling the impact of antibiotic use and infection control practices on the incidence of hospital-acquired methicillin-resistant Staphylococcus aureus: a time-series analysis

Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen worldwide. A wide range of factors have been suggested to influence the spread of MRSA. The objective of this study was to evaluate the effect of antimicrobial drug use and infection control practices on nosocomial MRSA incidence in a 426-bed general teaching hospital in Northern Ireland.

Methods: The present research involved the retrospective collection of monthly data on the usage of antibiotics and on infection control practices within the hospital over a 5 year period (January 2000–December 2004). A multivariate ARIMA (time-series analysis) model was built to relate MRSA incidence with antibiotic use and infection control practices.

Results: Analysis of the 5 year data set showed that temporal variations in MRSA incidence followed temporal variations in the use of fluoroquinolones, third-generation cephalosporins, macrolides and amoxicillin/clavulanic acid (coefficients = 0.005, 0.03, 0.002 and 0.003, respectively, with various time lags). Temporal relationships were also observed between MRSA incidence and infection control practices, i.e. the number of patients actively screened for MRSA (coefficient = -0.007), the use of alcohol-impregnated wipes (coefficient = -0.0003) and the bulk orders of alcohol-based handrub (coefficients = -0.04 and -0.08), with increased infection control activity being associated with decreased MRSA incidence, and between MRSA incidence and the number of new patients admitted with MRSA (coefficient = 0.22). The model explained 78.4% of the variance in the monthly incidence of MRSA.

Conclusions: The results of this study confirm the value of infection control policies as well as suggest the usefulness of restricting the use of certain antimicrobial classes to control MRSA.

Outreach and Early Warning Systems (EWS) for the prevention of intensive care admission and death of critically ill adult patients on general hospital wards

BACKGROUND: Despite the fact that outreach and early warning systems (EWS) are an integral part of a hospital wide systems approach to improve the early identification and management of deteriorating patients on general hospital wards, the widespread implementation of these interventions in practice is not based on robust research evidence. OBJECTIVES: The primary objective was to determine the impact of critical care outreach services on hospital mortality rates. Secondary objectives included determining the effect of outreach services on intensive care unit (ICU) admission patterns, length of hospital stay and adverse events. SEARCH STRATEGY: The review authors searched the following electronic databases: EPOC Specialised Register, The Cochrane Central Register of Controlled Trials (CENTRAL) and other Cochrane databases (all on The Cochrane Library 2006, Issue 3), MEDLINE (1996-June week 3 2006), EMBASE (1974-week 26 2006), CINAHL (1982-July week 5 2006), First Search (1992-2005) and CAB Health (1990-July 2006); also reference lists of relevant articles, conference abstracts, and made contact with experts and critical care organisations for further information. SELECTION CRITERIA: Randomised controlled trials (RCTs), controlled clinical trials (CCTs), controlled before and after studies (CBAs) and interrupted time series designs (ITS) which measured hospital mortality, unanticipated ICU admissions, ICU readmissions, length of hospital stay and adverse events following implementation of outreach and EWS in a general hospital ward to identify deteriorating adult patients versus general hospital ward setting without outreach and EWS were included in the review. DATA COLLECTION AND ANALYSIS: Three review authors independently extracted data and two review authors assessed the methodological quality of the included studies. Meta-analysis was not possible due to heterogeneity. Summary statistics and descriptive summaries of primary and secondary outcomes are presented for each study. MAIN RESULTS: Two cluster-randomised control trials were included: one randomised at hospital level (23 hospitals in Australia) and one at ward level (16 wards in the UK). The primary outcome in the Australian trial (a composite score comprising incidence of unexpected cardiac arrests, unexpected deaths and unplanned ICU admissions) showed no statistical significant difference between control and medical emergency team (MET) hospitals (adjusted P value 0.640; adjusted odds ratio (OR) 0.98; 95% confidence interval (CI) 0.83 to 1.16). The UK-based trial found that outreach reduced in-hospital mortality (adjusted OR 0.52; 95% CI 0.32 to 0.85) compared with the control group. AUTHORS' CONCLUSIONS: The evidence from this review highlights the diversity and poor methodological quality of most studies investigating outreach. The results of the two included studies showed either no evidence of the effectiveness of outreach or a reduction in overall mortality in patients receiving outreach. The lack of evidence on outreach requires further multi-site RCT's to determine potential effectiveness.

Quasiexperimental Study of the Effects of Antibiotic Use, Gastric Acid-Suppressive Agents, and Infection Control Practices on the Incidence of <i>Clostridium difficilei>-Associated Diarrhea in Hospitalized Patients

The objective of this study was to evaluate the effects of antimicrobial drug use, gastric acid-suppressive agent use, and infection control practices on the incidence of Clostridium difficile-associated diarrhea (CDAD) in a 426-bed general teaching hospital in Northern Ireland. The study was retrospective and ecological in design. A multivariate autoregressive integrated moving average (time-series analysis) model was built to relate CDAD incidence with antibiotic use, gastric acid-suppressive agent use, and infection control practices within the hospital over a 5-year period (February 2002 to March 2007). The findings of this study showed that temporal variation in CDAD incidence followed temporal variations in expanded-spectrum cephalosporin use (average delay = 2 months; variation of CDAD incidence = 0.01/100 bed-days), broad-spectrum cephalosporin use (average delay = 2 months; variation of CDAD incidence = 0.02/100 bed-days), fluoroquinolone use (average delay = 3 months; variation of CDAD incidence = 0.004/100 bed-days), amoxicillin-clavulanic acid use (average delay = 1 month; variation of CDAD incidence = 0.002/100 bed-days), and macrolide use (average delay = 5 months; variation of CDAD incidence = 0.002/100 bed-days). Temporal relationships were also observed between CDAD incidence and use of histamine-2 receptor antagonists (H2RAs; average delay = 1 month; variation of CDAD incidence = 0.001/100 bed-days). The model explained 78% of the variance in the monthly incidence of CDAD. The findings of this study highlight a temporal relationship between certain classes of antibiotics, H2RAs, and CDAD incidence. The results of this research can help hospitals to set priorities for restricting the use of specific antibiotic classes, based on the size-effect of each class and the delay necessary to observe an effect.

AUDIT OF ANTIBIOTIC USAGE IN A MEDIUM-SIZED GENERAL-HOSPITAL OVER AN 11-YEAR PERIOD - THE IMPACT OF ANTIBIOTIC POLICIES

The objective of the present study was to evaluate trends in antibiotic expenditure over an 11-year period (1982-1992) in a 370-bed district general hospital in Northern Ireland and to examine the impact of two separate antibiotic policies on antibiotic usage. A further objective was to examine the attitudes of prescribers to the second policy. Drug utilization review was used to collect information on antibiotic expenditure and usage before and after introduction of separate antibiotic policies in 1985 (not intensively monitored) and 1989 (intensively monitored). A mail questionnaire was used to determine the attitudes of prescribers. The first policy (1985) showed no benefits with regard to the number of antibiotic entities stocked (45 before, 45 after), number of dosage units issued (9.35 increase) or expenditure (33.35 increase). The 1989 policy led to significant reductions in the number of antibiotic entities stocked (28.9%), number of antibiotics issued (11.9%) and expenditure (6.1%). Expenditure began to spiral upwards when active monitoring of the second policy was suspended. The majority of prescribers (87.2%) who responded to the questionnaire (56.5% response rate) felt that the 1989 policy made a positive contribution to antibiotic usage in the hospital.

General Nurses’ Experiences of End-Of-Life Care in the Acute Hospital Setting

Approximately 90% of the UK population spend some time in hospital in their final year of life, and more than half of the population die in hospital. This review aims to explore the experiences of general nurses when providing end-of-life care to patients in the acute hospital setting. Nine studies were identified through a literature search, and each was then analysed and evaluated until themes emerged. Six themes were drawn from the literature: lack of education and knowledge, lack of time with patients, barriers arising in the culture of the health-care setting, communication barriers, symptom management, and nurses' personal issues. The themes cause concern about the quality of end-of-life care being provided in the acute care setting. The literature appears to be consistent in the view that terminally ill patients are best cared for in specialised care settings, such as palliative care units and hospices. However, increasing demands on health services will result in greater numbers of dying patients being admitted to the acute hospital setting. It is therefore paramount that general nurses' educational needs are met to ensure they develop clinical competence to provide high-quality holistic end-of-life care.