bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluating retrieval models using retrievability measurement
Authors: Bashir Shariq 
Published: May 2012

Evaluation is the main driving force in research, development and applications related to information retrieval (IR). In the traditional IR evaluation paradigm a list of query topics along with their relevance judgments are given. The main limitation of this kind of evaluation paradigm is that it focuses almost exclusively on a small set of judged documents and does not consider what influence the given retrieval models have on accessing all the relevant information in the collection. This is particularly important for recall oriented retrieval applications where we want to ensure that that everything relevant has been found.
In this thesis we analyze the effectiveness of retrieval models from the documents retrievability point of view. We focus particularly on the retrieval bias of different retrieval models, and try to examine to what extent this bias restricts the users in retrieving relevant information. We explore this research with the help of three factors. First, we analyze the relationship between different characteristics of queries and retrievability. This is important from the query generation point of view, since in case of exhaustive queries, it is practically infeasible to complete retrievability approximation in reasonable time. The strong correlation between retrievability and query characteristics allows us to approximate the retrievability score accurately with the help of a query subset without processing an exhaustive number of queries. After this, we examine to what extent the retrievability and other IR effectiveness measures are related to each other. This specifically helps us to understand to what extent it is possible to automatically rank the effectiveness of retrieval models on the basis of their retrieval bias. This also offers a basis for optimizing retrieval systems for specific collections without the need to provide manually annotated ground truth. This is particularly useful for those retrieval domains where it is difficult to obtain a sufficient amount of relevance judgments. At the end we investigate and devise different retrieval strategies for mitigating the effect of low retrievability of documents. These include collection partitioning and query expansion on the basis of improved pseudo relevance feedback selection.
The work present in this thesis provides an a novel approach for the evaluation and optimization of retrieval models particularly for recall oriented retrieval domains, where the focus is on retrieving all relevant information but not just retrieving a subset of relevant information. Available online at: http://www.ifs.tuwien.ac.at/~bashir/shariqbashir_phd_thesis.pdf.
Network meta-analysis of prasugrel, ticagrelor, high- and standard-dose clopidogrel in patients scheduled for percutaneous coronary interventions
Authors: Moertl Deddo , Chen Li , Coyle Doug , Wells George A. , Steiner Sabine 
Published: May 2012

SummarySince novel antiplatelet treatments (prasugrel, ticagrelor, high-dose clopidogrel) have been predominantly tested against standard-dose clopidogrel, data on direct comparisons between these therapies are scarce. We therefore indirectly compared their efficacy and safety in patients undergoing percutaneous coronary intervention. Electronic databases were searched systematically to identify head-to-head randomised controlled trials (RCTs). Network meta-analysis was performed using generalised linear mixed models with adjustment for length of follow-up. Findings were corroborated by mixed treatment comparison through Bayesian methods. Fourteen RCTs were identified and included in the analysis (high- vs. standard-dose clopidogrel: 9 trials, prasugrel vs. high-dose clopidogrel: 2 trials, prasugrel vs. standard-dose clopidogrel: 2 trials, ticagrelor vs. standard-dose clopidogrel: 1 trial). No significant differences were found for efficacy outcomes except for stent thrombosis favouring prasugrel (vs. ticagrelor: odds ratio [OR] 0.63, 95% confidence interval [CI]: 0.42, 0.94; vs. high-dose clopidogrel: OR 0.70, 95%CI: 0.48, 1.01). Prasugrel exhibited a similar bleeding risk as high-dose clopidogrel, but more major (OR 1.43, 95%CI 1.07, 1.90) and major or minor bleeding (OR 1.36, 95%CI 1.09, 1.69) compared to ticagrelor. Ticagrelor was also associated with less major or minor bleeding compared to high-dose clopidogrel (OR 0.81, 95%CI 0.69, 0.96). No differences were seen for non CABG-related major bleeding between the three strategies. Results were corroborated in a subgroup analysis comprising only patients with acute coronary syndromes. In the absence of head-to-head clinical trials, network meta-analysis suggests potentially relevant differences in efficacy and bleeding risk among novel antiplatelet treatments and may thereby advance understanding of their differential therapeutic properties.
Lethal factor VII deficiency due to novel mutations in the F7 promoter: Functional analysis reveals disruption of HNF4 binding site
Authors: Chafa Ouerdia , Tapon-Bretaudière Jacqueline , Claustres Mireille , Taulan Magali , Giansily-Blaizot Muriel , Lopez Estelle , Viart Victoria 
Published: May 2012

SummaryHereditary factor VII (FVII) deficiency is a rare autosomal recessive disorder. Deleterious mutations that prevent the synthesis of any amount of functional FVII have been associated with life-threatening haemorrhage in neonates. Here we report two infants, of Maghrebian origin, who suffered a fatal spontaneous cerebral haemorrhage. Investigation of the molecular basis for their severe FVII deficiency revealed novel mutations in a homozygous state within the F7 gene promoter: a single nucleotide substitution (c.-65G>C) and a 2bp deletion (c.-60_-59delTT). To determine whether these promoter variants were responsible for the FVII deficiency, computer–assisted sequence analyses were performed. The data predicted a disrupted binding of both HNF4 and COUP-TF transcription factors with each variant. Concordantly, experimental results revealed an altered HNF4-induced transactivation in the promoter mutated variants. The execution of functional tests is critical to ensuring a complete understanding of the effect of any promoter mutant on FVII deficiency. Only then can an accurate molecular diagnosis be made and further genetic counselling and prenatal diagnosis be offered.
Reactive leptin resistance and the profile of platelet activation in acute ischaemic stroke patients
Authors: Michalak Slawomir , Dworacki Grzegorz , Siewiera Karolina , Kaczmarek Mariusz , Watala Cezary , Kozubski Wojciech , Lukasik Maria 
Published: May 2012

SummaryLeptin is an adipokine that in vitro enhances agonist-induced platelet aggregation and adipokine expression. Hyperleptinaemia represents a risk factor for cardiovascular disease. We conducted a prospective evaluation of the potential link between blood platelet activation and plasma leptin levels in post-stroke patients. Using five-colour flow cyto-metry, the platelet surface expression of CD40L, CD62P, the subpopulations of monocyte-platelet aggregates and platelet-derived microparticles (PMPs) as well as the plasma leptin, soluble leptin receptor (sOb-R), leptin/sOb-R ratio, the plasma adiponectin, and leptin/adiponectin ratio were assessed in 98 stroke patients on the first (V0), 10th (V1) and 90th (V2) day after stroke and once in 78 age-, gender- and vascular risk factor-matched disease controls. We demonstrated that at V0 leptin resistance, defined as leptin/sOb-R ratio, was higher than in the controls [1.1 (0.5–1.8 vs. 0.5 (0.2–1.1); p=0.02]. After adjustment according to the factors which influence platelet activation, we confirmed the relationship between percentage of circulating PMPs and plasma leptin level (B=0.18; p=0.02) or the leptin/sOb-R ratio (B=0.23; p=0.02) in normal-weight subjects in the acute phase of stroke. No correlation could be demonstrated between the adipokine parameters and the percentage of monocyte-platelet aggregates or expression of platelet pro-inflammatory glycoproteins. In conclusion, formation of PMPs on the first day following an ischaemic stroke shows a positive correlation with leptin levels and with resistance to leptin. Leptin level does not seem to affect the expression of platelet surface proinflammatory glycoproteins.
Analytical challenges and technical limitations in assessing circulating MiRNAs
Authors: Mayr Manuel , Zampetaki Anna 
Published: May 2012

SummaryMiRNAs are emerging as promising biomarkers in cardiovascular diseases and may constitute a novel mechanism of intercellular communication. Accurate quantification of circulating miRNAs is essential. A variety of technological approaches and platforms have been developed with increased sensitivity and specificity for the detection and quantification of circulating miRNAs. In this review, we focus on the technical aspects and discuss the analytical challenges in profiling circulating miRNAs.
Anticoagulation in ambulatory cancer patients with no indication for prophylactic or therapeutic anticoagulation
Authors: Pishko Allyson M. , Smith Kenneth J. , Ragni Margaret V. 
Published: May 2012

SummaryVenous thromboembolism (VTE) occurs frequently in cancer patients and is a major cause of mortality. Although anticoagulation (AC) may have anti-tumour effects, it is recommended in cancer patients only for indications unrelated to these effects. A Markov model was constructed to estimate when prophylactic AC, given during four months of chemotherapy following a new cancer diagnosis, would be economically reasonable in ambulatory cancer patients with no VTE history. Risks and costs of major and minor bleeding, VTE, and death were obtained from the literature, including a 2011 Cochrane review of AC in cancer inpatients with no conventional indication. In the model, AC was low-molecular-weight-heparin (LMWH), and effects were modeled over a 24-month period. Model outputs were quality-adjusted life years (QALY) and the incremental cost-effectiveness ratio (ICER). In the base case analysis, when prophylactic AC had a two-year relative mortality risk of 0.92, there was a gain of 0.0354 QALY, for an ICER of $90,893/QALY gained, compared with no AC. In sensitivity analyses, AC prophylaxis cost less than $100,000/QALY, if two-year mortality exceeded 75%, or if AC costs were less than $1,076 per month, or if LMWH relative mortality risk was less than 0.927. Results were not sensitive to variation in VTE relative risk on AC, nor to major or minor bleeding risk on AC. A probabilistic sensitivity analysis also favoured prophylactic AC. In conclusion, prophylactic LMWH given to decrease cancer-related mortality, with no conventional indication, appears economically reasonable if its suggested mortality benefit is confirmed in future trials.
Blocking Toll-Like Receptors 7 and 9 Reduces Postinterventional Remodeling via Reduced Macrophage Activation, Foam Cell Formation, and Migration
Authors: Karper Jacco C. , Ewing Mark M. , Habets Kim L.L. , de Vries Margreet R. , Peters Erna A.B. , van Oeveren-Rietdijk Annemarie M. , de Boer Hetty C. , Hamming Jaap F. , Kuiper Johan , Kandimalla Ekambar R. , La Monica Nicola , Jukema J. Wouter , Quax Paul H.A. 
Published: May 2012

Objective—
The role of toll-like receptors (TLRs) in vascular remodeling is well established. However, the involvement of the endosomal TLRs is unknown. Here, we study the effect of combined blocking of TLR7 and TLR9 on postinterventional remodeling and accelerated atherosclerosis.

Methods and Results—

In hypercholesterolemic apolipoprotein E*3-Leiden mice, femoral artery cuff placement led to strong increase of TLR7 and TLR9 presence demonstrated by immunohistochemistry. Blocking TLR7/9 with a dual antagonist in vivo reduced neointimal thickening and foam cell accumulation 14 days after surgery by 65.6% (
P
=0.0079). Intima/media ratio was reduced by 64.5% and luminal stenosis by 62.8%. The TLR7/9 antagonist reduced the arterial wall inflammation, with reduced macrophage infiltration, decreased cytoplasmic high-mobility group box 1 expression, and altered serum interleukin-10 levels. Stimulation of cultured macrophages with TLR7 and TLR9 ligands enhanced tumor necrosis factor-α expression, which is decreased by TLR7/9 antagonist coadministration. Additionally, the antagonist abolished the TLR7/9-enhanced low-density lipoprotein uptake. The antagonist also reduced oxidized low-density lipoprotein–induced foam cell formation, most likely not via decreased influx but via increased efflux, because CD36 expression was unchanged whereas interleukin-10 levels were higher (36.1±22.3 pg/mL versus 128.9±6.6 pg/mL;
P
=0.008).

Conclusion—
Blocking TLR7 and TLR9 reduced postinterventional vascular remodeling and foam cell accumulation indicating TLR7 and TLR9 as novel therapeutic targets.
Chronic Administration of Oral Vasopressin Type 2 Receptor Antagonist Tolvaptan Exerts Both Myocardial and Renal Protective Effects in Rats With Hypertensive Heart Failure
Authors: Morooka Hanako , Iwanaga Yoshitaka , Tamaki Yodo , Takase Toru , Akahoshi Yasumitsu , Nakano Yoshimasa , Fujiki Hiroyuki , Miyazaki Shunichi 
Published: May 2012

Background—
Although recent clinical trials have demonstrated the efficacy of the oral vasopressin (AVP) type 2 receptor (V2R) antagonist tolvaptan, its long-term effects on the myocardium and kidney in heart failure (HF) are not clear. We examined the chronic effects of tolvaptan administration on both the myocardium and kidney in a rat hypertensive HF model.

Methods and Results—

Not only circulating AVP level but also myocardial AVP and V1a receptor (V1aR) expressions, renal V1aR, and V2R expressions were significantly upregulated during the transition to HF. The animals were chronically treated with low-dose or high-dose (HD) tolvaptan or vehicle from the left ventricular (LV) hypertrophic stage. Chronic tolvaptan treatment persistently increased urine volume but did not affect blood pressure. In the HD group, the animal survival significantly improved (log-rank test,
P
<0.01). At the HF stage, the progression of LV dysfunction was prevented and lung congestion was suppressed. Activation of atrial natriuretic peptide, endothelin-1, AVP, and V1aR mRNA levels were significantly suppressed in the LV myocardium. Meanwhile, renal histopathologic damage was ameliorated and renal function was improved in the HD group at the HF stage. Concomitantly, not only activation of aquaporin-2 but also those of V2R, V1aR, renin, and endothelin-1 in the kidney were significantly suppressed (all
P
<0.05).

Conclusions—
These results indicate that chronic tolvaptan treatment has beneficial effects by preventing not only the progression of LV dysfunction but also that of renal injury in hypertensive rats with HF. The underlying mechanism may be related to the suppression of myocardial and renal neurohumoral activation.
Relation Between Change in Blood Pressure in Acute Stroke and Risk of Early Adverse Events and Poor Outcome
Authors: Sandset Else C. , Murray Gordon D. , Bath Philip M.W. , Kjeldsen Sverre E. , Berge Eivind 
Published: May 2012

Background and Purpose—
The Scandinavian Candesartan Acute Stroke Trial (SCAST) found no benefits of candesartan in acute stroke. In the present analysis we aim to investigate the effect of change in blood pressure during the first 2 days of stroke on the risk of early adverse events and poor outcome.

Methods—
SCAST was a multicenter, randomized controlled, double-blind trial of candesartan in acute stroke. The trial recruited 2029 patients presenting within 30 hours of acute stroke and with systolic blood pressure (SBP) ≥140 mm Hg. Treatment was given for 7 days. Change in blood pressure was defined as the difference in SBP between baseline and Day 2 and was used to divide patients into groups with increase/no change, a small decrease, moderate decrease, or large decrease in SBP. The primary effect parameter was early adverse events (recurrent stroke, stroke progression, and symptomatic hypotension) during the first 7 days, analyzed using logistic regression, with the group with a small decrease in SBP as the reference group. Secondary effect parameters were neurological status at 7 days and functional outcome at 6 months.

Results—

Patients with a large decrease or increase/no change in SBP had a significantly increased risk of early adverse events relative to patients with a small decrease (OR, 2.08; 95% CI, 1.19–3.65 and OR, 1.96; 95% CI, 1.13–3.38, respectively). Patients with an increase/no change in SBP had a significantly increased risk of poor neurological outcome as compared with the other groups (
P
=0.001). No differences were observed in functional outcome at 6 months.

Conclusions—
Our findings support the suggestion from SCAST that blood pressure reduction may be harmful and that routine blood pressure-lowering treatment should probably be avoided in the acute phase.

Clinical Trial Information—

Clinical Trial Registration:
www.clinicaltrials.gov
. Unique identifier: NCT00120003.
Poststroke Disposition and Associated Factors in a Population-Based Study
Authors: Béjot Yannick , Troisgros Odile , Gremeaux Vincent , Lucas Brigitte , Jacquin Agnès , Khoumri Catia , Aboa-Eboulé Corine , Benaïm Charles , Casillas Jean-Marie , Giroud Maurice 
Published: May 2012

Background and Purpose—
The organization of poststroke care will be a major challenge in coming years. We aimed to assess hospital disposition after stroke and its associated factors in clinical practice.

Methods—
All cases of stroke from 2006 to 2010 were identified from the population-based Stroke Registry of Dijon, France. Demographic features, risk factors, and prestroke treatments were recorded. Admission stroke severity was assessed using the National Institutes of Health Stroke Scale score. At discharge, we collected dementia, disability using the modified Rankin Scale, length of stay, and hospital disposition (home, rehabilitation, convalescent home, and nursing home). Multivariate analyses were performed using logistic regression models to identify associated factors of postdischarge disposition.

Results—
Of the patients with 1069 stroke included, 913 survived acute care. Among them, 433 (47.4%) returned home, whereas 206 (22.6%) were discharged to rehabilitation, 134 (14.7%) were admitted to a convalescent home, and 140 (15.3%) to a nursing home. Old patients, those under anticoagulants before stroke, those with severe stroke on admission, severe disability at discharge, dementia, or prolonged length of stay were less likely to return home. Moreover, advanced age, severe initial stroke, severe disability at discharge, and dementia were associated with admission to convalescent and nursing homes rather than rehabilitation centers.

Conclusion—
This population-based study demonstrated that postdischarge destinations are associated with several factors. Our findings may be useful to establish health policy concerning the organization of poststroke care.
Nonstationary Trapped Lee Waves Generated by the Passage of an Isolated Jet
Authors: Hills Matthew O. G. , Durran Dale R. 
Published: May 2012

Abstract
The behavior of nonstationary trapped lee waves in a nonsteady background flow is studied using idealized three-dimensional (3D) numerical simulations. Trapped waves are forced by the passage of an isolated, synoptic-scale barotropic jet over a mountain ridge of finite length. Trapped waves generated within this environment differ significantly in their behavior compared with waves in the more commonly studied two-dimensional (2D) steady flow. After the peak zonal flow has crossed the terrain, two disparate regions form within the mature wave train: 1) upwind of the jet maximum, trapped waves increase their wavelength and tend to untrap and decay, whereas 2) downwind of the jet maximum, wavelengths shorten and waves remain trapped. Waves start to untrap approximately 100 km downwind of the ridge top, and the region of untrapping expands downwind with time as the jet progresses, while waves downstream of the jet maximum persist. Wentzel–Kramers–Brillouin (WKB) ray tracing shows that spatial gradients in the mean flow are the key factor responsible for these behaviors. An example of real-world waves evolving similarly to the modeled waves is presented.
As expected, trapped waves forced by steady 2D and horizontally uniform unsteady 3D flows decay downstream because of leakage of wave energy into the stratosphere. Surprisingly, the downstream decay of lee waves is inhibited by the presence of a stratosphere in the isolated-jet simulations. Also unexpected is that the initial trapped wavelength increases quasi-linearly throughout the event, despite the large-scale forcing at the ridge crest being symmetric in time about the midpoint of the isolated-jet simulation.
Pharmacologically Dosed Oral Glutamine Reduces Myocardial Injury in Patients Undergoing Cardiac Surgery
Authors: Sufit Alexandra , Weitzel Lindsay B. , Hamiel Christine , Queensland Kelly , Dauber Ira , Rooyackers Olav , Wischmeyer Paul E. 
Published: May 2012

Background and Objective:Glutamine (GLN) has been shown to protect against in vitro and in vivo myocardial injury. In humans, perioperative ischemia/reperfusion (I/R) injury during cardiac surgery is associated with higher morbidity and mortality. The objective of this safety and feasibility pilot trial was to determine if pharmacologically dosed, preoperative oral GLN attenuates myocardial injury in cardiac surgery patients.Methods:Patients undergoing elective cardiac surgery, requiring cardiopulmonary bypass, were enrolled in a randomized, double‐blind pilot trial to receive 25 g twice of oral alanyl‐glutamine (GLN; n = 7) or maltodextrin (CONT; n = 7) daily for 3 days preoperatively. Serum troponin (TROP I), creatine kinase (CK‐MB), and myoglobin (MG) were measured at multiple perioperative time points. Clinical outcomes were also recorded and assessed.Results:GLN therapy significantly decreased TROP I levels at 24, 48, and 72 hours postoperatively (all P < .05) vs CONT. GLN also reduced CK‐MB at 24 and 48 hours (P < .05, P < .001) vs CONT. MG was reduced at 24 hours vs control (P = .0397). GLN also significantly reduced pooled clinical complications vs CONT (P = .03).Conclusion:This pilot study showed that pharmacologically dosed oral GLN therapy prior to cardiac surgery was safe, well tolerated, and feasible. GLN therapy reduced myocardial injury and clinical complications in this small randomized, blinded feasibility trial. These data indicate that a larger trial of preoperative GLN therapy in patients undergoing cardiac surgery is needed to confirm clinical benefit.