1,310 research outputs found

    Improved ventricular function during inhalation of PGI(2) aerosol partly relies on enhanced myocardial contractility

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    Inhaled prostacyclin (PGI(2)) aerosol induces selective pulmonary vasodilation. Further, it improves right ventricular ( RV) function, which may largely rely on pulmonary vasodilation, but also on enhanced myocardial contractility. We investigated the effects of the inhaled PGI(2) analogs epoprostenol (EPO) and iloprost (ILO) on RV function and myocardial contractility in 9 anesthetized pigs receiving aerosolized EPO (25 and 50 ng center dot kg(-1) center dot min(-1)) and, consecutively, ILO (60 ng center dot kg(-1) center dot min(-1)) for 20 min each. We measured pulmonary artery pressure ( PAP), RV ejection fraction (RVEF) and RV end-diastolic-volume (RV-EDV), and left ventricular end-systolic pressure-volume-relation (end-systolic elastance, E-es). EPO and ILO reduced PAP, increased RVEF and reduced RVEDV. E-es was enhanced during all doses tested, which reached statistical significance during EPO25ng and ILO, but not during EPO50ng. PGI(2) aerosol enhances myocardial contractility in healthy pigs, contributing to improve RV function. Copyright (C) 2005 S. Karger AG, Basel

    A rapid intrapartum test for group B Streptococcus to reduce antibiotic usage in mothers with risk factors: the GBS2 cluster RCT

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    BACKGROUND: Mother-to-baby transmission of group B Streptococcus (Streptococcus agalactiae) is the main cause of early-onset infection. OBJECTIVES: We investigated if intrapartum antibiotic prophylaxis directed by a rapid intrapartum test reduces maternal and neonatal antibiotic use, compared with usual care (i.e. risk factor-directed antibiotics), among women with risk factors for vertical group B Streptococcus transmission, and examined the accuracy and cost-effectiveness of the rapid test. DESIGN: An unblinded cluster randomised controlled trial with a nested test accuracy study, an economic evaluation and a microbiology substudy. SETTING: UK maternity units were randomised to either a strategy of rapid test or usual care. PARTICIPANTS: Vaginal and rectal swabs were taken from women with risk factors for vertical group B Streptococcus transmission in established term labour. The accuracy of the GeneXpert® Dx IV GBS rapid testing system (Cepheid, Maurens-Scopont, France) was compared with the standard of selective enrichment culture in diagnosing maternal group B Streptococcus colonisation. MAIN OUTCOME MEASURES: Primary outcomes were rates of intrapartum antibiotic prophylaxis administered to prevent early-onset group B Streptococcus infection and accuracy estimates of the rapid test. Secondary outcomes were maternal antibiotics for any indication, neonatal antibiotic exposure, maternal antibiotic duration, neonatal group B Streptococcus colonisation, maternal and neonatal antibiotic resistance, neonatal morbidity and mortality, and cost-effectiveness of the strategies. RESULTS: Twenty-two maternity units were randomised and 20 were recruited. A total of 722 mothers (749 babies) participated in rapid test units and 906 mothers (951 babies) participated in usual-care units. There were no differences in the rates of intrapartum antibiotic prophylaxis for preventing early-onset group B Streptococcus infection in the rapid test units (41%, 297/716) compared with the usual-care units (36%, 328/906) (risk ratio 1.16, 95% confidence interval 0.83 to 1.64). There were no differences between the groups in intrapartum antibiotic administration for any indication (risk ratio 0.99, 95% confidence interval 0.81 to 1.21). Babies born in the rapid test units were 29% less likely to receive antibiotics (risk ratio 0.71, 95% confidence interval 0.54 to 0.95) than those born in usual-care units. The sensitivity and specificity of the rapid test were 86% (95% confidence interval 81% to 91%) and 89% (95% confidence interval 85% to 92%), respectively. In 14% of women (99/710), the rapid test was invalid or the machine failed to provide a result. In the economic analysis, the rapid test was shown to be both less effective and more costly and, therefore, dominated by usual care. Sensitivity analysis indicated potential lower costs for the rapid test strategy when neonatal costs were included. No serious adverse events were reported. CONCLUSIONS: The Group B Streptococcus 2 (GBS2) trial found no evidence that the rapid test reduces the rates of intrapartum antibiotic prophylaxis administered to prevent early-onset group B Streptococcus infection. The rapid test has the potential to reduce neonatal exposure to antibiotics, but economically is dominated by usual care. The accuracy of the test is within acceptable limits. FUTURE WORK: The role of routine testing for prevention of neonatal infection requires evaluation in a randomised controlled trial. TRIAL REGISTRATION: Current Controlled Trials ISRCTN74746075. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 12. See the NIHR Journals Library website for further project information

    Developing a manually annotated clinical document corpus to identify phenotypic information for inflammatory bowel disease

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    <p>Abstract</p> <p>Background</p> <p>Natural Language Processing (NLP) systems can be used for specific Information Extraction (IE) tasks such as extracting phenotypic data from the electronic medical record (EMR). These data are useful for translational research and are often found only in free text clinical notes. A key required step for IE is the manual annotation of clinical corpora and the creation of a reference standard for (1) training and validation tasks and (2) to focus and clarify NLP system requirements. These tasks are time consuming, expensive, and require considerable effort on the part of human reviewers.</p> <p>Methods</p> <p>Using a set of clinical documents from the VA EMR for a particular use case of interest we identify specific challenges and present several opportunities for annotation tasks. We demonstrate specific methods using an open source annotation tool, a customized annotation schema, and a corpus of clinical documents for patients known to have a diagnosis of Inflammatory Bowel Disease (IBD). We report clinician annotator agreement at the document, concept, and concept attribute level. We estimate concept yield in terms of annotated concepts within specific note sections and document types.</p> <p>Results</p> <p>Annotator agreement at the document level for documents that contained concepts of interest for IBD using estimated Kappa statistic (95% CI) was very high at 0.87 (0.82, 0.93). At the concept level, F-measure ranged from 0.61 to 0.83. However, agreement varied greatly at the specific concept attribute level. For this particular use case (IBD), clinical documents producing the highest concept yield per document included GI clinic notes and primary care notes. Within the various types of notes, the highest concept yield was in sections representing patient assessment and history of presenting illness. Ancillary service documents and family history and plan note sections produced the lowest concept yield.</p> <p>Conclusion</p> <p>Challenges include defining and building appropriate annotation schemas, adequately training clinician annotators, and determining the appropriate level of information to be annotated. Opportunities include narrowing the focus of information extraction to use case specific note types and sections, especially in cases where NLP systems will be used to extract information from large repositories of electronic clinical note documents.</p

    Evidence-based nanoscopic and molecular framework for excipient functionality in compressed orally disintegrating tablets

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    The work investigates the adhesive/cohesive molecular and physical interactions together with nanoscopic features of commonly used orally disintegrating tablet (ODT) excipients microcrystalline cellulose (MCC) and D-mannitol. This helps to elucidate the underlying physico-chemical and mechanical mechanisms responsible for powder densification and optimum product functionality. Atomic force microscopy (AFM) contact mode analysis was performed to measure nano-adhesion forces and surface energies between excipient-drug particles (6-10 different particles per each pair). Moreover, surface topography images (100 nm2-10 μm2) and roughness data were acquired from AFM tapping mode. AFM data were related to ODT macro/microscopic properties obtained from SEM, FTIR, XRD, thermal analysis using DSC and TGA, disintegration testing, Heckel and tabletability profiles. The study results showed a good association between the adhesive molecular and physical forces of paired particles and the resultant densification mechanisms responsible for mechanical strength of tablets. MCC micro roughness was 3 times that of D-mannitol which explains the high hardness of MCC ODTs due to mechanical interlocking. Hydrogen bonding between MCC particles could not be established from both AFM and FTIR solid state investigation. On the contrary, D-mannitol produced fragile ODTs due to fragmentation of surface crystallites during compression attained from its weak crystal structure. Furthermore, AFM analysis has shown the presence of extensive micro fibril structures inhabiting nano pores which further supports the use of MCC as a disintegrant. Overall, excipients (and model drugs) showed mechanistic behaviour on the nano/micro scale that could be related to the functionality of materials on the macro scale. © 2014 Al-khattawi et al

    Plant Diversity Changes during the Postglacial in East Asia: Insights from Forest Refugia on Halla Volcano, Jeju Island

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    Understanding how past climate changes affected biodiversity is a key issue in contemporary ecology and conservation biology. These diversity changes are, however, difficult to reconstruct from paleoecological sources alone, because macrofossil and pollen records do not provide complete information about species assemblages. Ecologists therefore use information from modern analogues of past communities in order to get a better understanding of past diversity changes. Here we compare plant diversity, species traits and environment between late-glacial Abies, early-Holocene Quercus, and mid-Holocene warm-temperate Carpinus forest refugia on Jeju Island, Korea in order to provide insights into postglacial changes associated with their replacement. Based on detailed study of relict communities, we propose that the late-glacial open-canopy conifer forests in southern part of Korean Peninsula were rich in vascular plants, in particular of heliophilous herbs, whose dramatic decline was caused by the early Holocene invasion of dwarf bamboo into the understory of Quercus forests, followed by mid-Holocene expansion of strongly shading trees such as maple and hornbeam. This diversity loss was partly compensated in the Carpinus forests by an increase in shade-tolerant evergreen trees, shrubs and lianas. However, the pool of these species is much smaller than that of light-demanding herbs, and hence the total species richness is lower, both locally and in the whole area of the Carpinus and Quercus forests. The strongly shading tree species dominating in the hornbeam forests have higher leaf tissue N and P concentrations and smaller leaf dry matter content, which enhances litter decomposition and nutrient cycling and in turn favored the selection of highly competitive species in the shrub layer. This further reduced available light and caused almost complete disappearance of understory herbs, including dwarf bamboo

    Managing Relationship Decay Network, Gender, and Contextual Effects

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    Relationships are central to human life strategies and have crucial fitness consequences. Yet, at the same time, they incur significant maintenance costs that are rarely considered in either social psychological or evolutionary studies. Although many social psychological studies have explored their dynamics, these studies have typically focused on a small number of emotionally intense ties, whereas social networks in fact consist of a large number of ties that serve a variety of different functions. In this study, we examined how entire active personal networks changed over 18 months across a major life transition. Family relationships and friendships differed strikingly in this respect. The decline in friendship quality was mitigated by increased effort invested in the relationship, but with a striking gender difference: relationship decline was prevented most by increased contact frequency (talking together) for females but by doing more activities together in the case of males

    Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

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    Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

    Evidence for the h_b(1P) meson in the decay Upsilon(3S) --> pi0 h_b(1P)

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    Using a sample of 122 million Upsilon(3S) events recorded with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we search for the hb(1P)h_b(1P) spin-singlet partner of the P-wave chi_{bJ}(1P) states in the sequential decay Upsilon(3S) --> pi0 h_b(1P), h_b(1P) --> gamma eta_b(1S). We observe an excess of events above background in the distribution of the recoil mass against the pi0 at mass 9902 +/- 4(stat.) +/- 2(syst.) MeV/c^2. The width of the observed signal is consistent with experimental resolution, and its significance is 3.1sigma, including systematic uncertainties. We obtain the value (4.3 +/- 1.1(stat.) +/- 0.9(syst.)) x 10^{-4} for the product branching fraction BF(Upsilon(3S)-->pi0 h_b) x BF(h_b-->gamma eta_b).Comment: 8 pages, 4 postscript figures, submitted to Phys. Rev. D (Rapid Communications
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