327 research outputs found

    Substrate Based Ablation of Ventricular Tachycardia Through An Epicardial Approach

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    Ventricular tachycardia (VT) occurring late after myocardial infarction is often due to reentry circuit in the peri-infarct zone. The circuit is usually located in the sub-endocardium, though subepicardial substrates are known. Activation mapping during VT to identify target regions for ablation can be difficult if VT is non inducible or poorly tolerated. In the latter, a substrate based approach of mapping during sinus rhythm in conjunction with pace mapping helps to define the reentry circuit and select target sites for ablation in majority of patients with hemodynamically unstable VT. Percutaneous epicardial catheter ablation has been attempted as an approach where ablation by a conventional endocardial access has been unsuccessful. We report a case of post myocardial infarction scar VT which could be successfully ablated with a substrate based approach from the epicardial aspect

    Optimiranje uvjeta uzgoja radi povećanja biomase lišaja Usnea ghattensis G. Awasthi i stvaranja veće količine metabolita s antioksidacijskim svojstvima

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    The aim of this study is to optimize the culture conditions for lichen Usnea ghattensis G. Awasthi in order to increase biomass and antioxidant metabolite production. The cultured lichen consisted of usnic acid produced by mycobionts and photobionts after 2 to 3 months of inoculation. Cultures grown in the media with excess carbon sources showed significant increment in the biomass growth, usnic acid production and total polyphenol mass fraction after six months of inoculation. The methanol extract of six-month-old cultures grown in the malt-yeast extract (MYE) medium containing 0.01 mol/L of sucrose and 0.01 mol/L of polyethylene glycol showed a significantly high inhibition of lipid peroxidation activity up to 89 %. A significant correlation (R^2=0.89) of p<0.01 was also found between total polyphenol mass fraction and the inhibition of lipid peroxidation in this lichen species.Svrha je ovog istraživanja bila optimirati uvjete uzgoja radi povećanja biomase lišaja Usnea ghatteniss G. Awasthi i dobivanja veće količine metabolita koji imaju antioksidativni učinak. Uzgojeni je lišaj (simbiont alge i gljive) ispitan 2-3 mjeseca nakon inokulacije te je utvrđeno da sadrži usninsku kiselinu. Također je ustanovljeno da je uzgojem na podlozi s povećanim udjelom ugljikovih spojeva tijekom 6 mjeseci dobivena kudikamo veća biomasa lišaja s većim masenim udjelima usninske kiseline i ukupnih polifenola. Ispitani metanolni ekstrakt kultura dobivenih šestomjesečnim uzgojem na podlozi od maltoznog i kvaščeva ekstrakta s dodatkom 0,01 mol/L saharoze i 0,01 mol/L polietilenglikola znatno je inhibirao peroksidaciju lipida, čak i do 89 %. Utvrđena je značajna pozitivna korelacija (R^2=0,89; p<0,01) između masenog udjela ukupnih polifenola u ispitanoj vrsti lišaja i inhibicije lipidne peroksidacije

    Techno-environ-economical analysis of floating PV/on-ground PV/grid extension systems for electrification of a remote area in India

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    Remote area electrification is a major concern for a government of any developing nation. India is also working for it but despite continuous efforts towards remote area electrification, several thousand households in India are un-electrified. Several schemes have been launched by Government for electrification of such areas through grid extension but still many areas have not been covered under the proposed schemes due to economic, environmental and geographical reasons. Narayanpur district in Chhattisgarh state of India has un-electrified regions and various issues like poor literacy, untreated water facility and lack of access to communication networks. In order to find viable option of electricity supply to this region, a case study has been performed for the feasibility of off-grid floating photovoltaic (PV) system, on-ground PV system and grid extension along with their comparative analysis with respect to certain parameters i.e. net present value (NPV), cost of energy (CoE), environment cleanliness and social acceptance. Floating PV and on-ground PV systems have been designed and simulated using System Adviser Model (SAM) software developed by National Renewable Energy Laboratory (NREL), USA. The results show that floating PV system has lowest CoE of 0.0598/kWhandleastnegativeNPVof0.0598/kWh and least negative NPV of 185,431 as compared to other two options. However, it is found that floating PV system achieves positive NPV of $38,968 in 28th year of project life.http://www.springer.com/journal/40866hj2022Electrical, Electronic and Computer Engineerin

    Unusual tumours of the heart: diagnostic and prognostic implications

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    Metastases to the heart are extremely uncommon. We describe three unusual cases along with their management. A review of the current literature concerning cardiac secondaries is included

    Cardiovascular-protective, antioxidative, and antimicrobial properties of natural thallus of lichen Usnea complanata

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    In this study the cardiovascular protective antioxidative and antimicrobial properties of natural thallus of lichen Usnea complanata has been reported. Ethyl acetate extract showed maximum HMG-CoA reductase inhibitory activity up to 52.87 % at 200 μg/ml. Ethanol extract at same concentration showed 46.37 % inhibition of angiotensin converting enzyme. Maximum fibrinolytic activity was obtained in ethanol extract followed by hexane extract. Ethanol extract of U. complanata showed antioxidative activity as scavenging of nitric oxide radical, free radical scavenging and lipid peroxidation inhibition with an IC50 value ranging from 0.062 to 0.27 μg/ml, which was lower than the other solvent extracts. All extract with the exception of DMSO and hexane showed inhibitory activity against bacteria and fungi. Ethyl acetate extract was found to be most efficient as MIC90 was found in the range 4.61 – 21.55 μg/ml. Acetone and ethyl acetate extract inhibited all the tested fungi with MIC values ranged from 6.25 to 100 μg/ml and 12.5 to 100 μg/ml, respectively. Cardiovascular protective and antioxidative properties were shown strong correlation with the total polyphenol content present in the extract with R2 value ranging from 0.585 to 0.927.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Impact of audiovisual biofeedback on interfraction respiratory motion reproducibility in liver cancer stereotactic body radiotherapy.

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    INTRODUCTION: Irregular breathing motion exacerbates uncertainties throughout a course of radiation therapy. Breathing guidance has demonstrated to improve breathing motion consistency. This was the first clinical implementation of audiovisual biofeedback (AVB) breathing guidance over a course of liver stereotactic body radiotherapy (SBRT) investigating interfraction reproducibility. METHODS: Five liver cancer patients underwent a screening procedure prior to CT sim during which patients underwent breathing conditions (i) AVB, or (ii) free breathing (FB). Whichever breathing condition was more regular was utilised for the patient's subsequent course of SBRT. Respiratory motion was obtained from the Varian respiratory position monitoring (RPM) system (Varian Medical Systems). Breathing motion reproducibility was assessed by the variance of displacement across 10 phase-based respiratory bins over each patient's course of SBRT. RESULTS: The screening procedure yielded the decision to utilise AVB for three patients and FB for two patients. Over the course of SBRT, AVB significantly improved the relative interfraction motion by 32%, from 22% displacement difference for FB patients to 15% difference for AVB patients. Further to this, AVB facilitated sub-millimetre interfraction reproducibility for two AVB patients. CONCLUSION: There was significantly less interfraction motion with AVB than FB. These findings demonstrate that AVB is potentially a valuable tool in ensuring reproducible interfraction motion

    Thirty Years After Michael E. Porter: What Do We Know About Business Exit?

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    Although a business exit is an important corporate change initiative, the buyer’s side seems to be more appealing to management researchers than the seller’s because acquisitions imply growth, i.e., success. Yet from an optimistic viewpoint, business exit can effectively create value for the selling company. In this paper we attempt to bring the relevance of the seller’s side back into our consciousness by asking: What do we know about business exit? We start our exploration with Porter (1976), focusing on literature that investigates the antecedents of, barriers to, and outcomes of business exit. We also include studies from related fields such as finance and economics.1 Through this research we determine three clusters of findings: factors promoting business exit, exit barriers, and exit outcomes. Overall, it is the intention of this paper to highlight the importance of business exit for research and practice. Knowing what we know about business exits and their high financial value we should bear in mind that exit need not mean failure but a new beginning for a corporation

    Practices participating in a dental PBRN have substantial and advantageous diversity even though as a group they have much in common with dentists at large

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    <p>Abstract</p> <p>Background</p> <p>Practice-based research networks offer important opportunities to move recent advances into routine clinical practice. If their findings are not only generalizable to dental practices at large, but can also elucidate how practice characteristics are related to treatment outcome, their importance is even further elevated. Our objective was to determine whether we met a key objective for The Dental Practice-Based Research Network (DPBRN): to recruit a diverse range of practitioner-investigators interested in doing DPBRN studies.</p> <p>Methods</p> <p>DPBRN participants completed an enrollment questionnaire about their practices and themselves. To date, more than 1100 practitioners from the five participating regions have completed the questionnaire. The regions consist of: Alabama/Mississippi, Florida/Georgia, Minnesota, Permanente Dental Associates, and Scandinavia (Denmark, Norway, and Sweden). We tested the hypothesis that there are statistically significant differences in key characteristics among DPBRN practices, based on responses from dentists who participated in DPBRN's first network-wide study (n = 546).</p> <p>Results</p> <p>There were statistically significant, substantive regional differences among DPBRN-participating dentists, their practices, and their patient populations.</p> <p>Conclusion</p> <p>Although as a group, participants have much in common with practices at large; their substantial diversity offers important advantages, such as being able to evaluate how practice differences may affect treatment outcomes, while simultaneously offering generalizability to dentists at large. This should help foster knowledge transfer in both the research-to-practice and practice-to-research directions.</p

    Endotypes of difficult-to-control asthma in inner-city African American children

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    African Americans have higher rates of asthma prevalence, morbidity, and mortality in comparison with other racial groups. We sought to characterize endotypes of childhood asthma severity in African American patients in an inner-city pediatric asthma population. Baseline blood neutrophils, blood eosinophils, and 38 serum cytokine levels were measured in a sample of 235 asthmatic children (6–17 years) enrolled in the NIAID (National Institute of Allergy and Infectious Diseases)-sponsored Asthma Phenotypes in the Inner City (APIC) study (ICAC (Inner City Asthma Consortium)-19). Cytokines were quantified using a MILLIPLEX panel and analyzed on a Luminex analyzer. Patients were classified as Easy-to-Control or Difficult-to-Control based on the required dose of controller medications over one year of prospective management. A multivariate variable selection procedure was used to select cytokines associated with Difficult-to-Control versus Easy-to-Control asthma, adjusting for age, sex, blood eosinophils, and blood neutrophils. In inner-city African American children, 12 cytokines were significant predictors of Difficult-to-Control asthma (n = 235). CXCL-1, IL-5, IL-8, and IL-17A were positively associated with Difficult-to-Control asthma, while IL-4 and IL-13 were positively associated with Easy-to-Control asthma. Using likelihood ratio testing, it was observed that in addition to blood eosinophils and neutrophils, serum cytokines improved the fit of the model. In an inner-city pediatric population, serum cytokines significantly contributed to the definition of Difficult-to-Control asthma endotypes in African American children. Mixed responses characterized by TH2 (IL-5) and TH17-associated cytokines were associated with Difficult-to-Control asthma. Collectively, these data may contribute to risk stratification of Difficult-to-Control asthma in the African American population
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