507 research outputs found

    Influence of contrast media dose and osmolality on the diagnostic performance of contrast fractional flow reserve

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    Background—Contrast fractional flow reserve (cFFR) is a method for assessing functional significance of coronary stenoses, which is more accurate than resting indices and does not require adenosine. However, contrast media volume and osmolality may affect the degree of hyperemia and therefore diagnostic performance. Methods and Results—cFFR, instantaneous wave–free ratio, distal pressure/aortic pressure at rest, and FFR were measured in 763 patients from 12 centers. We compared the diagnostic performance of cFFR between patients receiving low or iso-osmolality contrast (n=574 versus 189) and low or high contrast volume (n=341 versus 422) using FFR≤0.80 as a reference standard. The sensitivity, specificity, and overall accuracy of cFFR for the low versus iso-osmolality groups were 73%, 93%, and 85% versus 87%, 90%, and 89%, and for the low versus high contrast volume groups were 69%, 99%, and 83% versus 82%, 93%, and 88%. By receiver operating characteristics (ROC) analysis, cFFR provided better diagnostic performance than resting indices regardless of contrast osmolality and volume (P<0.001 for all groups). There was no significant difference between the area under the curve of cFFR in the low- and iso-osmolality groups (0.938 versus 0.957; P=0.40) and in the low- and high-volume groups (0.939 versus 0.949; P=0.61). Multivariable logistic regression analysis showed that neither contrast osmolality nor volume affected the overall accuracy of cFFR; however, both affected the sensitivity and specificity. Conclusions—The overall accuracy of cFFR is greater than instantaneous wave–free ratio and distal pressure/aortic pressure and not significantly affected by contrast volume and osmolality. However, contrast volume and osmolality do affect the sensitivity and specificity of cFFR

    Exclusive breastfeeding and its effect on growth of Malawian infants: results from a cross-sectional study

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    Abstract Background: For the optimal nutrition of children under 2 years of age, it is considered important that they be exclusively breastfed for the first 6 months before being given complementary food. Aims and Objectives: A cross-sectional nutritional baseline survey was undertaken in 2011 in the Kasungu and Mzimba Districts of Malawi to assess the nutritional status of children under 2 years of age and its determinants in order to prepare a nutrition education intervention programme. The intention of this study was to assess the nutritional status of infants aged 0–<6 months with regard to food intake. Methods: Interviews were conducted on randomly selected families with children under 2 years; anthropometric measurements were obtained from mothers and their children. Only infants between 0 and <6 months were selected for analysis (n  =  196). An ANCOVA test was performed on age of the infant with mothers’ height and weight as covariates. Results: Prevalence of stunting (infants’ length-for-age Z-score (LAZ) <−2SD) was 39%, wasting (WLZ <−2SD) 2%, and underweight (WAZ <−2SD) 13%. Of the infants under 6 months, 43% were exclusively breastfed. Predominant breastfeeding and mixed breastfeeding were less common (21% and 36%, respectively). The ANCOVA confirmed the association between exclusive breastfeeding and LAZ and WAZ: exclusively breastfed infants had a higher mean (SE) LAZ (−1·13, 0·12) and WAZ (−0·41, 0·13) than infants not being exclusively breastfed (−1·59, 0·11, and −0·97, 0·11, respectively). There was no overall significant association between breastfeeding practice and WLZ. Conclusion: Exclusive breastfeeding of infants under 6 months is associated with higher mean LAZ and WAZ. Promotion of exclusive breastfeeding in low-income countries is important in preventing growth retardation

    Pilot testing of enhanced sorbents for calcium looping with cement production

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    One of the main challenges for commercialising calcium looping (CaL) as a CO2 capture technology is maintaining a high level of sorbent reactivity during long-term cycling. In order to mitigate the decay in carrying capacity, research has moved towards producing enhanced sorbents. However, this creates potential problems related to ease of scaling up production techniques and production costs, and raises the question as to whether such approaches can be used at large scale. On the other hand, a key advantage of CaL over other carbon capture technologies is synergy with the cement industry, i.e., use of spent sorbent as a feedstock for clinker production. In this work two enhanced materials: (i) limestone doped with HBr through a particle surface impregnation technique; and (ii) pellets prepared from limestone and calcium aluminate cement, were tested in a 25 kWth dual fluidised bed pilot-scale reactor in order to investigate their capture performance and mechanical stability under realistic CaL conditions. Moreover, the spent sorbent was then used as a raw material to make cement, which was characterised for phase and chemical composition as well as compressive strength. The HBr-doped limestone showed better performance in terms of both mechanical strength and stability of the CO2 uptake when compared to that of pellets. Furthermore, it was shown that the cement produced has similar characteristics and performance as those of commercial CEM 1 cement. This indicates the advantages of using the spent sorbent as feedstock for cement manufacture and shows the benefits of synthetic sorbents in CaL and suitability of end-use of spent sorbents for the cement industry, validating their synergy at pilot scale. Finally, this study demonstrates the possibility of using several practical techniques to improve the performance of CaL at the pilot scale, and more importantly demonstrates that commercial-grade cement can be made from the lime product from this technology

    The individual’s perception of institutional environments and entrepreneurial motivation in developing economies: Evidence from Cape Verde

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    Background: International organisations and national governments have made great efforts to stimulate entrepreneurial activity in the less-advanced economies, but the results of their programmes have often been disappointing. This may be because a distinction between the institutional factors that generate an individual’s desire to become an entrepreneur and those that generate a motivation that actually leads to entrepreneurial action has not been considered sufficiently. Aim: This work is an attempt to respond to the following question on the basis of the individual’s perception of regulative, normative and cognitive institutions: In developing economies, what institutional factors generate an entrepreneurial motivation that makes individuals desire to become entrepreneurs and what factors cause an entrepreneurial motivation that actually leads them to entrepreneurial action? Setting: We use empirical evidence from the African nation of Cape Verde for the analysis. The study was carried out on 6 of the 10 islands of the archipelago. Method: The sample of study comprises 237 people: 93 entrepreneurs and 144 individuals with different levels of desire to become an entrepreneur. We used multiple linear regression analysis to test the hypotheses. Results: Our findings show that institutional factors which generate the entrepreneurial motivation that forges an individual’s desire to become an entrepreneur, and those which generate the motivation that leads him or her to actually set up his or her own business are not the same. We also find differences in the institutional factors that influence the opportunity, necessity and social components of entrepreneurial motivation. Conclusion: Theoretical implications for better understanding the factors that condition entrepreneurship in developing economies and practical implications useful for improving the planning of growth in these countries are offered

    MATH APPS UTILIZATION: ITS PERCEIVED EFFECTS TO THE ACADEMIC PERFORMANCE OF MATHEMATICS MAJOR STUDENTS

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    This study aimed to determine the perceived effects of apps utilization to study habits and academic performance. Further, it also sought to determine the views of the participants and respondents on their engagement in math apps and their relationship with study habits and academic performance. This study made use of explanatory-sequential design. The purposive sampling design was used to determine the respondents in quantitative data while the quota sampling design was also used to determine the participants in qualitative data. The study revealed that the mathematical application that is mostly used by the students is the calculator app as it garnered the highest percentage value of 80.85.%. The participants agreed that math applications serve as an aid for math problems, aid for lack of teaching by the teacher, promote learning of specific lessons and increase, and help in improving their academic performance. Respondents’ perception of their utilization of math apps is due to technical problems. The respondents also agreed that math application also affected their study habits in which they become dependent on it which led to laziness and tiredness. In addition, this study also found that there is a significant relationship between respondents’ utilization of math applications and their study habits. Lastly, there is also a significant relationship between the study habits and academic performance of selected math students of Notre Dame of Midsayap College.  Article visualizations

    Continuum of vasodilator stress from rest to contrast medium to adenosine hyperemia for fractional flow reserve assessment

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    Objectives: This study compared the diagnostic performance with adenosine-derived fractional flow reserve (FFR) ≤0.8 of contrast-based FFR (cFFR), resting distal pressure (Pd)/aortic pressure (Pa), and the instantaneous wave-free ratio (iFR). Background: FFR objectively identifies lesions that benefit from medical therapy versus revascularization. However, FFR requires maximal vasodilation, usually achieved with adenosine. Radiographic contrast injection causes submaximal coronary hyperemia. Therefore, intracoronary contrast could provide an easy and inexpensive tool for predicting FFR. Methods: We recruited patients undergoing routine FFR assessment and made paired, repeated measurements of all physiology metrics (Pd/Pa, iFR, cFFR, and FFR). Contrast medium and dose were per local practice, as was the dose of intracoronary adenosine. Operators were encouraged to perform both intracoronary and intravenous adenosine assessments and a final drift check to assess wire calibration. A central core lab analyzed blinded pressure tracings in a standardized fashion. Results: A total of 763 subjects were enrolled from 12 international centers. Contrast volume was 8 ± 2 ml per measurement, and 8 different contrast media were used. Repeated measurements of each metric showed a bias &lt;0.005, but a lower SD (less variability) for cFFR than resting indexes. Although Pd/Pa and iFR demonstrated equivalent performance against FFR ≤0.8 (78.5% vs. 79.9% accuracy; p = 0.78; area under the receiver-operating characteristic curve: 0.875 vs. 0.881; p = 0.35), cFFR improved both metrics (85.8% accuracy and 0.930 area; p &lt; 0.001 for each) with an optimal binary threshold of 0.83. A hybrid decision-making strategy using cFFR required adenosine less often than when based on either Pd/Pa or iFR. Conclusions: cFFR provides diagnostic performance superior to that of Pd/Pa or iFR for predicting FFR. For clinical scenarios or health care systems in which adenosine is contraindicated or prohibitively expensive, cFFR offers a universal technique to simplify invasive coronary physiological assessments. Yet FFR remains the reference standard for diagnostic certainty as even cFFR reached only ∼85% agreement

    High IRF8 expression correlates with CD8 T cell infiltration and is a predictive biomarker of therapy response in ER-negative breast cancer

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    Characterization of breast cancer (BC) through the determination of conventional markers such as ER, PR, HER2 and Ki67 has been useful as a predictive and therapeutic tool. Also, assessment of tumor-infiltrating lymphocytes has been proposed as an important prognostic aspect to be considered in certain BC subtypes. However, there is still a need to identify additional biomarkers that could add precision indistinguishing therapeutic response of individual patients. To this end, we focused in the expression of Interferon regulatory factor 8 (IRF8) in BC cells. IRF8 is a transcription factor which plays a well determined role in myeloid cells and that seems to have multiple antitumoral roles: it has tumor suppressor functions; it acts down stream IFN/STAT1, required for the success of some therapeutic regimes and its expression in neoplastic cells seems to depend on a cross talk between the immune contexture and the tumor cells.The goal of the present study was to examine the relationship between IRF8 with the therapeutic response and the immune contexture in BC, since its clinical significance in this type of cancer has not been thoroughly addressed. We identified the relationship between IRF8 expression and the clinical outcome of BCpatients and validated IRF8 as predictive biomarker by using public databases and then performed in silico analysis. To correlate the expression of IRF8 with the immune infiltrate in BC samples we performed quantitative multiplex immuno histochemistry. IRF8 expression can precisely predict the complete pathological response to monoclonal antibody therapy or to select combinations of chemotherapy such as FAC (Fluorouracil, Adriamycin and Cytoxan) in ER negative BC subtypes. Analysis of immune cell infiltration indicates there is a strong correlation between activated and effector CD8 + T cell infiltration and tumoral IRF8 expression. Conclusions Wepropose IRF8 expression as a potent biomarker not only for prognosis, but also forpredicting therapy response in ER negative BC phenotypes. Its expression inneoplastic cells also correlates with CD8 + T cell activation and infiltration. Therefore, our results justify new efforts towards understanding mechanisms regulating IRF8 expression and how they can be therapeutically manipulated.Fil: Gatti, Gerardo Alberto. Fundación Para El Progreso de la Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Betts, Courtney. Oregon Health & Science University; Estados UnidosFil: Rocha, Darío Gastón. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Nicola, Maribel. Fundación Para El Progreso de la Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Grupe, Verónica Maria. Fundación Para El Progreso de la Medicina; ArgentinaFil: Ditada, Cecilia. Fundación Para El Progreso de la Medicina; ArgentinaFil: Núñez, Nicolás G.. Institute Of Experimental Immunology; Suiza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Roselli, Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Araya, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Dutto, Jeremias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Boffelli, Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Fernández, Elmer. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Desarrollo en Inmunología y Enfermedades Infecciosas. Universidad Católica de Córdoba. Centro de Investigación y Desarrollo en Inmunología y Enfermedades Infecciosas; ArgentinaFil: Coussens, Lisa M.. Knight Cancer Institute; Estados UnidosFil: Maccioni, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentin

    Effects of N-acetyl-cysteine on endothelial function and inflammation in patients with type 2 diabetes mellitus

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    Endothelial dysfunction has been associated with premature vascular disease. There is increasing data that N-acetyl-cysteine (NAC) may prevent or improve endothelial dysfunction. The aim of this study was to assess the effects of NAC on endothelial function in patients with type 2 diabetes mellitus, a population at high risk for endothelial dysfunction. Twenty-four patients with diabetes mellitus were assigned randomly to initial therapy with either 900 mg NAC or placebo twice daily in a double-blind, cross-over study design. Flowmediated vasodilation (FMD) of the brachial artery was assessed at baseline, after four weeks of therapy, after a four-week wash-out period, and after another four weeks on the opposite treatment. Plasma and red blood cell glutathione levels and high-sensitivity C-reactive protein (CRP) were measured at all four visits. At baseline, FMD was moderately impaired (3.7±2.9%). There was no significant change in FMD after four weeks of NAC therapy as compared to placebo (0.1±3.6% vs. 1.2±4.2%). Similarly, there was no significant change in glutathione levels. However, median CRP decreased from 2.35 to 2.14 mg/L during NAC therapy (p=0.04), while it increased from 2.24 to 2.65 mg/L with placebo. No side effects were noted during the treatment period. In this double-blind, randomized cross-over study, four weeks of oral NAC therapy failed to improve endothelial dysfunction in patients with diabetes mellitus. However, NAC therapy decreased CRP levels, suggesting that this compound may have some efficacy in reducing systemic inflammation
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