732 research outputs found

    Analytic Representation of Finite Quantum Systems

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    A transform between functions in R and functions in Zd is used to define the analogue of number and coherent states in the context of finite d-dimensional quantum systems. The coherent states are used to define an analytic representation in terms of theta functions. All states are represented by entire functions with growth of order 2, which have exactly d zeros in each cell. The analytic function of a state is constructed from its zeros. Results about the completeness of finite sets of coherent states within a cell are derived

    Blood transfusion in the critically ill: does storage age matter?

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    Morphologic and biochemical changes occur during red cell storage prior to product expiry, and these changes may hinder erythrocyte viability and function following transfusion. Despite a relatively large body of literature detailing the metabolic and structural deterioration that occurs during red cell storage, evidence for a significant detrimental clinical effect related to the transfusion of older blood is relatively less conclusive, limited primarily to observations in retrospective studies. Nonetheless, the implication that the transfusion of old, but not outdated blood may have negative clinical consequences demands attention. In this report, the current understanding of the biochemical and structural changes that occur during storage, known collectively as the storage lesion, is described, and the clinical evidence concerning the detrimental consequences associated with the transfusion of relatively older red cells is critically reviewed. Although the growing body of literature demonstrating the deleterious effects of relatively old blood is compelling, it is notable that all of these reports have been retrospective, and most of these studies have evaluated patients who received a mixture of red cell units of varying storage age. Until prospective studies have been completed and produce confirmative results, it would be premature to recommend any modification of current transfusion practice regarding storage age

    Epidemiological Features of Infantile Hypertrophic Pyloric Stenosis in Taiwanese Children: A Nation-Wide Analysis of Cases during 1997–2007

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    OBJECTIVE: To describe the epidemiological characteristics of infantile hypertrophic pyloric stenosis (IHPS) in ethnic Chinese children. MATERIALS AND METHODS: We reviewed the National Health Insurance claims database and analyzed data from children less than one year of age who had been diagnosed with IHPS (ICD-9-CM 750.5) and had undergone pyloromyotomy (ICD-9-CM 43.3). We analyzed the incidence, gender, age at diagnosis, length of hospital stay, seasonal variation and cost of IHPS from data collected between January 1997 and December 2007. RESULTS: A total of 1,077 infants met inclusion criteria, including 889 boys and 188 girls. The annual incidence of IHPS ranged from 0.30 to 0.47 per 1,000 live births with a mean incidence of 0.39 per 1,000 live births. Between 2002 and 2007, the incidence showed a declining trend (P = 0.025) with coincidentally increasing trends for both exclusive breastfeeding (P = 0.014) and breastfeeding plus bottle feeding (P = 0.004). The male-to-female rate ratio was dynamic and increased from 3.03 during the first two weeks of life to 8.94 during the 8(th) through 10th weeks of life. The overall male-to-female rate ratio was 4.30. The mean age at diagnosis was 43.1 ± 2.4 days. After analyzing the months of birth and hospital admission, no seasonal variation associated with IHPS was detected. The mean length of hospital stay was 8.28 ± 7.10 days. CONCLUSIONS: The incidence of IHPS in Taiwan, a country with a majority ethnic Chinese population, was lower than observed incidences in Caucasian populations living in Western countries. Breastfeeding campaigns and low maternal smoking rates may contribute to the lower incidence of IHPS in Taiwan. However, additional studies with longer follow-up periods are needed

    Prognosis of ovarian cancer subsequent to venous thromboembolism: a nationwide Danish cohort study

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    BACKGROUND: Venous thromboembolism (VTE) is associated with ovarian cancer and may impact the prognosis of ovarian cancer. Our aims were to examine the extent of disease at the time of the diagnosis of ovarian cancer and to estimate the impact of VTE on survival of ovarian cancer. METHODS: We identified 12,835 ovarian cancer patients diagnosed from 1980 to 2003 in the Danish Cancer Registry and obtained information on previous primary VTE diagnosis from the Danish National Hospital Discharge Registry. Ovarian cancer patients with previous VTE related to other cancers, surgery, or pregnancy were excluded. The vital status was determined by linking data to the Civil Registration System. RESULTS: We identified 50 ovarian cancer patients diagnosed less than 4 months after the VTE and 78 ovarian cancer patients diagnosed more than 4 months after the VTE diagnosis. Advanced stages tended to be more common among patients with VTE. One-year survivals were 44% and 54% among the two VTE groups, compared with 63% among patients without VTE. Adjusted (for age, calendar time, comorbidity, and FIGO-stage) mortality ratios were 1.7 (95% CI = 1.2–2.5) and 1.2 (95% CI = 0.8–1.7), respectively. CONCLUSION: Ovarian cancer diagnosed less than four months before VTE is associated with an advanced stage and a poorer prognosis

    The role of ICT in supporting disruptive innovation: a multi-site qualitative study of nurse practitioners in emergency departments

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    <p>Abstract</p> <p>Background</p> <p>The disruptive potential of the Nurse Practitioner (NP) is evident in their ability to offer services traditionally provided by primary care practitioners and their provision of a health promotion model of care in response to changing health trends. No study has qualitatively investigated the role of the Emergency NP in Australia, nor the impact of Information and Communication Technology (ICT) on this disruptive workforce innovation. This study aimed to investigate ways in which Nurse Practitioners (NP) have incorporated the use of ICT as a mechanism to support their new clinical role within Emergency Departments.</p> <p>Methods</p> <p>A cross-sectional qualitative study was undertaken in the Emergency Departments (EDs) of two large Australian metropolitan public teaching hospitals. Semi-structured, in-depth interviews were conducted with five nurse practitioners, four senior physicians and five senior nurses. Transcribed interviews were analysed using a grounded theory approach to develop themes in relation to the conceptualisation of the ED nurse practitioner role and the influences of ICT upon the role. Member checking of results was achieved by revisiting the sites to clarify findings with participants and further explore emergent themes.</p> <p>Results</p> <p>The role of the ENP was distinguished from those of Emergency nurses and physicians by two elements: advanced practice and holistic care, respectively. ICT supported the advanced practice dimension of the NP role in two ways: availability and completeness of electronic patient information enhanced timeliness and quality of diagnostic and therapeutic decision-making, expediting patient access to appropriate care. The ubiquity of patient data sourced from a central database supported and improved quality of communication between health professionals within and across sites, with wider diffusion of the Electronic Medical Record holding the potential to further facilitate team-based, holistic care.</p> <p>Conclusions</p> <p>ICT is a facilitator through which the disruptive impact of NPs can be extended. However, integration of ICT into work practices without detracting from provider-patient interaction is crucial to ensure utilisation of such interventions and realisation of potential benefits.</p
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