4,207 research outputs found

    The removal of thermally aged films of triacylglycerides by surfactant solutions

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    Thermal ageing of triacylglycerides (TAG) at high temperatures produces films which resist removal using aqueous surfactant solutions. We used a mass loss method to investigate the removal of thermally aged TAG films from hard surfaces using aqueous solutions of surfactants of different charge types. It was found that cationic surfactants are most effective at high pH, whereas anionics are most effective at low pH and a non-ionic surfactant is most effective at intermediate pH. We showed that the TAG film removal process occurs in several stages. In the first ‘‘lag phase’’ no TAG removal occurs; the surfactant first partitions into the thermally aged film. In the second stage, the TAG film containing surfactant was removed by solubilisation into micelles in the aqueous solution. The effects of pH and surfactant charge on the TAG removal process correlate with the effects of these variables on the extent of surfactant partitioning to the TAG film and on the maximum extent of TAG solubilisation within the micelles. Additionally, we showed how the TAG removal is enhanced by the addition of amphiphilic additives such as alcohols which act as co-surfactants. The study demonstrates that aqueous surfactant solutions provide a viable and more benign alternative to current methods for the removal of thermally aged TAG films

    Breast-Lesion Characterization using Textural Features of Quantitative Ultrasound Parametric Maps

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    © 2017 The Author(s). This study evaluated, for the first time, the efficacy of quantitative ultrasound (QUS) spectral parametric maps in conjunction with texture-analysis techniques to differentiate non-invasively benign versus malignant breast lesions. Ultrasound B-mode images and radiofrequency data were acquired from 78 patients with suspicious breast lesions. QUS spectral-analysis techniques were performed on radiofrequency data to generate parametric maps of mid-band fit, spectral slope, spectral intercept, spacing among scatterers, average scatterer diameter, and average acoustic concentration. Texture-analysis techniques were applied to determine imaging biomarkers consisting of mean, contrast, correlation, energy and homogeneity features of parametric maps. These biomarkers were utilized to classify benign versus malignant lesions with leave-one-patient-out cross-validation. Results were compared to histopathology findings from biopsy specimens and radiology reports on MR images to evaluate the accuracy of technique. Among the biomarkers investigated, one mean-value parameter and 14 textural features demonstrated statistically significant differences (p < 0.05) between the two lesion types. A hybrid biomarker developed using a stepwise feature selection method could classify the legions with a sensitivity of 96%, a specificity of 84%, and an AUC of 0.97. Findings from this study pave the way towards adapting novel QUS-based frameworks for breast cancer screening and rapid diagnosis in clinic

    Automated COVID-19 and Heart Failure Detection Using DNA Pattern Technique with Cough Sounds.

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    COVID-19 and heart failure (HF) are common disorders and although they share some similar symptoms, they require different treatments. Accurate diagnosis of these disorders is crucial for disease management, including patient isolation to curb infection spread of COVID-19. In this work, we aim to develop a computer-aided diagnostic system that can accurately differentiate these three classes (normal, COVID-19 and HF) using cough sounds. A novel handcrafted model was used to classify COVID-19 vs. healthy (Case 1), HF vs. healthy (Case 2) and COVID-19 vs. HF vs. healthy (Case 3) automatically using deoxyribonucleic acid (DNA) patterns. The model was developed using the cough sounds collected from 241 COVID-19 patients, 244 HF patients, and 247 healthy subjects using a hand phone. To the best our knowledge, this is the first work to automatically classify healthy subjects, HF and COVID-19 patients using cough sounds signals. Our proposed model comprises a graph-based local feature generator (DNA pattern), an iterative maximum relevance minimum redundancy (ImRMR) iterative feature selector, with classification using the k-nearest neighbor classifier. Our proposed model attained an accuracy of 100.0%, 99.38%, and 99.49% for Case 1, Case 2, and Case 3, respectively. The developed system is completely automated and economical, and can be utilized to accurately detect COVID-19 versus HF using cough sounds

    The impact of hyperhidrosis on patients' daily life and quality of life : A qualitative investigation

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    Background: An understanding of the daily life impacts of hyperhidrosis and how patients deal with them, based on qualitative research, is lacking. This study investigated the impact of hyperhidrosis on the daily life of patients using a mix of qualitative research methods. Methods: Participants were recruited through hyperhidrosis patient support groups such as the Hyperhidrosis Support Group UK. Data were collected using focus groups, interviews and online surveys. A grounded theory approach was used in the analysis of data transcripts. Data were collected from 71 participants, out of an initial 100 individuals recruited. Results: Seventeen major themes capturing the impacts of hyperhidrosis were identified; these covered all areas of life including daily life, psychological well-being, social life, professional /school life, dealing with hyperhidrosis, unmet health care needs and physical impact. Conclusions: Psychosocial impacts are central to the overall impacts of hyperhidrosis, cutting across and underlying the limitations experienced in other areas of life.Peer reviewe

    Millennial atmospheric CO2 changes linked to ocean ventilation modes over past 150,000 years

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    Ice core measurements show diverse atmospheric CO2 variations—increasing, decreasing or remaining stable—during millennial-scale North Atlantic cold periods called stadials. The reasons for these contrasting trends remain elusive. Ventilation of carbon-rich deep oceans can profoundly affect atmospheric CO2, but its millennial-scale history is poorly constrained. Here we present a well-dated high-resolution deep Atlantic acidity record over the past 150,000 years, which reveals five hitherto undetected modes of stadial ocean ventilation with different consequences for deep-sea carbon storage and associated atmospheric CO2 changes. Our data provide observational evidence to show that strong and often volumetrically extensive Southern Ocean ventilation released substantial amounts of deep-sea carbon during stadials when atmospheric CO2 rose prominently. By contrast, other stadials were characterized by weak ventilation via both Southern Ocean and North Atlantic, which promoted respired carbon accumulation and thus curtailed or reversed deep-sea carbon losses, resulting in diminished rises or even declines in atmospheric CO2. Our findings demonstrate that millennial-scale changes in deep-sea carbon storage and atmospheric CO2 are modulated by multiple ocean ventilation modes through the interplay of the two polar regions, rather than by the Southern Ocean alone, which is critical for comprehensive understanding of past and future carbon cycle adjustments to climate change

    A combinatorial TIR1/AFB–Aux/IAA co-receptor system for differential sensing of auxin

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    The plant hormone auxin regulates virtually every aspect of plant growth and development. Auxin acts by binding the F-box protein transport inhibitor response 1 (TIR1) and promotes the degradation of the AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) transcriptional repressors. Here we show that efficient auxin binding requires assembly of an auxin co-receptor complex consisting of TIR1 and an Aux/IAA protein. Heterologous experiments in yeast and quantitative IAA binding assays using purified proteins showed that different combinations of TIR1 and Aux/IAA proteins form co-receptor complexes with a wide range of auxin-binding affinities. Auxin affinity seems to be largely determined by the Aux/IAA. As there are 6 TIR1/AUXIN SIGNALING F-BOX proteins (AFBs) and 29 Aux/IAA proteins in Arabidopsis thaliana, combinatorial interactions may result in many co-receptors with distinct auxin-sensing properties. We also demonstrate that the AFB5–Aux/IAA co-receptor selectively binds the auxinic herbicide picloram. This co-receptor system broadens the effective concentration range of the hormone and may contribute to the complexity of auxin response

    Decline in Clostridium difficile-associated disease rates in Singapore public hospitals, 2006 to 2008

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    <p>Abstract</p> <p>Background</p> <p><it>Clostridium difficile </it>is the major cause of pseudomembranous colitis associated with antibiotic use, and the spread of the hypervirulent epidemic ribotype 027/NAP-1 strain across hospitals worldwide has re-focused attention on this nosocomial pathogen. The overall incidence and trend of <it>C. difficile</it>-associated disease (CDAD) in Singapore is unknown, and a surveillance program to determine these via formal laboratory-based reporting was established.</p> <p>Findings</p> <p>Laboratory and pharmacy data were collated from one tertiary and two secondary hospitals on a quarterly basis between 2006 and 2008. All hospitals tested for <it>C. difficile </it>using Immunocard Toxins A&B (Meridian Bioscience Inc., Cincinnati, OH) during this period. Duplicate positive <it>C. difficile </it>results within a 14-day period were removed. The CDAD results were compared with trends in hospital-based prescription of major classes of antibiotics.</p> <p>Overall CDAD incidence-density decreased from 5.16 (95%CI: 4.73 - 5.62) cases per 10,000 inpatient-days in 2006 to 2.99 (95%CI: 2.67 to 3.33) cases per 10,000 inpatient-days in 2008 (<it>p </it>< 0.001), while overall rates for <it>C. difficile </it>testing increased significantly (<it>p </it>< 0.001) within the same period. These trends were mirrored at the individual hospital level. Evaluation of antibiotic prescription data at all hospitals showed increasing use of carbapenems and fluoroquinolones, while cephalosporin and clindamycin prescription remained stable.</p> <p>Conclusions</p> <p>Our results demonstrate a real decline of CDAD rates in three large local hospitals. The cause is unclear and is not associated with improved infection control measures or reduction in antibiotic prescription. Lack of <it>C. difficile </it>stool cultures as part of routine testing precluded determination of the decline of a major clone as a potential explanation. For more accurate epidemiological trending of CDAD and early detection of epidemic clones, data collection will have to be expanded and resources set in place for reference laboratory culture and typing.</p

    What happens if you single out? An experiment

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    We present an experiment investigating the effects of singling out an individual on trust and trustworthiness. We find that (a) trustworthiness falls if there is a singled out subject; (b) non-singled out subjects discriminate against the singled out subject when they are not responsible of the distinct status of this person; (c) under a negative frame, the singled out subject returns significantly less; (d) under a positive frame, the singled out subject behaves bimodally, either selecting very low or very high return rates. Overall, singling out induces a negligible effect on trust but is potentially disruptive for trustworthiness

    Laparoscopic nephrectomy for giant staghorn calculus with non-functioning kidneys: Is associated unsuspected urothelial carcinoma responsible for conversion? Report of 2 cases

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    BACKGROUND-: Neglected renal stones remain a major cause of morbidity in developing countries. They not only result in functional impairment of affected kidney, but also act as an important predisposing factor for development of urothelial neoplasms. It is not uncommon to miss an associated urothelial tumor in a patient of nephrolithiasis preoperatively. CASE PRESENTATION-: In last 3 years, we came across two patients with giant staghorn calculus and poorly functioning kidneys who underwent laparoscopic nephrectomy. In view of significant perirenal adhesions & loss of normal tissue planes both these patients were electively converted to open surgery. The pathological examination of specimen revealed an unsuspected urothelial carcinoma in both these patients. The summary of our cases and review of literature is presented. CONCLUSION-: It is important to keep a differential diagnosis of associated urothelial malignancy in mind in patient presenting with long standing renal calculi. The exact role of a computerized tomography and cytology in preoperative workup for detection of possible associated malignancy in such condition is yet to be defined. Similarly if laparoscopic dissection appears difficult during nephrectomy for a renal calculus with non-functional kidney, keeping a possibility of associated urothelial malignancy in mind it is advisable to dissect in a plane outside gerotas fascia as for radical nephrectomy
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