103 research outputs found

    Single-molecule interfacial electron transfer dynamics manipulated by external electric current

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    Interfacial electron transfer (IET) dynamics in 1,1'-dioctadecyl-3, 3, 3', 3'-tetramethylindodicarbocyanine (DiD) dye molecules / indium tin oxide (ITO) film system have been probed at the ensemble and single-molecule level by recording the change of fluorescence emission intensity. By comparing the difference of the external electric current (EEC) dependence of lifetime and intensity for enambles and single molecules, it is shown that the single-molecule probe can effcienly demonstrate the IET dynamics. The backward electron transfer and electron transfer of ground state induce the single molecules fluorescence quenching when an EEC is applied to ITO film.Comment: 6 pages, 6 figure

    Exploring the limits of single emitter detection in fluorescence and extinction

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    We present an experimental comparison and a theoretical analysis of the signal-to-noise ratios in fluorescence and extinction spectroscopy of a single emitter. We show that extinction measurements can be advantageous if the emitter is weakly excited. Furthermore, we discuss the potential of this method for the detection and spectroscopy of weakly emitting systems such as rare earth ions.Comment: 11 pages, 5 figure

    Thermoregulation and heterothermy in some of the smaller flying foxes (Megachiroptera) of New Guinea

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    Body temperature, heterothermy, oxygen consumption, heart rate, and evaporative water loss were studied in four species of flying foxes (Megachiroptera), Dobsonia minor, Nyctimene major, Nyctimene albiventer , and Paranyctimene raptor , from the vicinity of Madang on the north coast of New Guinea.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47105/1/359_2004_Article_BF00297716.pd

    Cognitive behavioural therapy in elderly type 2 diabetes patients with minor depression or mild major depression: study protocol of a randomized controlled trial (MIND-DIA)

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    <p>Abstract</p> <p>Background</p> <p>The global prevalence of diabetes among adults will be 6.4% in 2010 and will increase to 7.7% by 2030. Diabetes doubles the odds of depression, and 9% of patients with diabetes are affected by depressive disorders. When subclinical depression is included, the proportion of patients who have clinically relevant depressive symptoms increases to 26%. In patients aged over 65 years, the interaction of diabetes and depression has predicted increased mortality, complications, disability, and earlier occurrence of all of these adverse outcomes. These deleterious effects were observed even in minor depression, where the risk of mortality within 7 years was 4.9 times higher compared with diabetes patients who did not have depressive symptoms. In this paper we describe the design and methods of the Minor Depression and Diabetes trial, a clinical trial within the 'Competence Network for Diabetes mellitus', which is funded by the German Federal Ministry of Education and Research.</p> <p>Methods/Design</p> <p>Patients' inclusion criteria are: Type 2 diabetes mellitus, 65 to 85 years of age, 3 to 6 depressive symptoms (minor depression or mild major depression). Our aim is to compare the efficacy of diabetes-specific cognitive behavioural therapy adapted for the elderly vs. intensified treatment as usual vs. a guided self-help intervention regarding improvement of health related quality of life as the primary outcome. The trial will be conducted as a multicentre, open, observer-blinded, parallel group (3 groups) randomized controlled trial. Patients will be randomized to one of the three treatment conditions. After 12 weeks of open-label therapy in all treatment conditions, both group interventions will be reduced to one session per month during the one-year long-term phase of the trial. At the one-year follow-up, all groups will be re-examined regarding the primary and secondary parameters, for example reduction of depressive symptoms, prevention of moderate/severe major depression, improvement of glycaemic control, mortality, and cost effectiveness. Depending on additional funding, the sample will be continuously observed as a prospective cohort; the primary outcome will be changed to mortality for all subsequent follow-up measurements.</p> <p>Trial registration</p> <p>Current Controlled Trials Register (ISRCTN58007098).</p

    Microdialysis-based 48-hour continuous glucose monitoring with GlucoDay (TM) : clinical performance and patients' acceptance

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    BACKGROUND: This study was designed to assess clinical performance and patients&#039; acceptance of the minimally invasive microdialysis-based continuous glucose monitoring system Gluco- Day() (Menarini Diagnostics, Florence, Italy) with a targeted monitoring time of 48 h. METHODS: An inpatient sample of 28 patients with diabetes was studied. The analysis of clinical performance was performed using mean absolute differences (MAD) (in percent), Pearson correlations, the Bland-Altman analysis, and Clarke Error Grid Analysis (EGA). GlucoDay glucose values were compared with laboratory standard blood glucose measurements (glucohexokinase assay). The patients&#039; acceptance of the monitoring device was assessed via two self-report scales (pain during application and discomfort while wearing device). RESULTS: A mean (+/- SD) monitoring time of 45.7 +/- 3.3 h with a total of 484 paired readings could be achieved. A correlation of r (average) = 0.91 and a MAD of 19.9% indicated satisfactory to good clinical performance. Of the paired readings, 95.5% fell into the acceptable A and B zones of the EGA. Rather wide 95% limits of agreement were revealed in the Bland-Altman analysis. Whereas virtually no pain was experienced during sensor application, discomfort associated with wearing the device was rather high. All of the participants, however, stated that they would wear the device again. CONCLUSIONS: Satisfactory to good performance of the GlucoDay monitor was observed, indicating the device to be suitable for routine clinical use. In particular, however, the discomfort experienced during wearing requires further improvements in its usability

    Lower rates of ART initiation and decreased retention among ART-naïve patients who consume alcohol enrolling in HIV care and treatment programs in Kenya and Uganda

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    Objectives Almost 13 million people are estimated to be on antiretroviral therapy in Eastern and Southern Africa, and their disease course and program effectiveness could be significantly affected by the concurrent use of alcohol. Screening for alcohol use may be important to assess the prevalence of alcohol consumption and its impact on patient and programmatic outcomes. Methods As part of this observational study, data on patient characteristics and alcohol consumption were collected on a cohort of 765 adult patients enrolling in HIV care in East Africa. Alcohol consumption was assessed with the AUDIT questionnaire at enrollment. Subjects were classified as consuming any alcohol (AUDIT score &gt;0), hazardous drinkers (AUDIT score ≥8) and hyper drinkers (AUDIT score ≥16). The effects of alcohol consumption on retention in care, death and delays in antiretroviral therapy (ART) initiation were assessed through competing risk (Fine &amp; Gray) models. Results Of all study participants, 41.6% consumed alcohol, 26.7% were classified as hazardous drinkers, and 16.0% as hyper drinkers. Depending on alcohol consumption classification, men were 3–4 times more likely to consume alcohol compared to women. Hazardous drinkers (median age 32.8 years) and hyper drinkers (32.7 years) were slightly older compared to non-hazardous drinkers (30.7 years) and non-hyper drinkers (30.8 years), (p-values = 0.014 and 0.053 respectively). Median CD4 at enrollment was 330 cells/μl and 16% were classified World Health Organization (WHO) stage 3 or 4. There was no association between alcohol consumption and CD4 count or WHO stage at enrollment. Alcohol consumption was associated with significantly lower probability of ART initiation (adjusted sub-distribution hazard ratio aSHR = 0.77 between alcohol consumers versus non-consumers; p-value = 0.008), and higher patient non-retention in care (aSHR = 1.77, p-value = 0.023). Discussion Alcohol consumption is associated with significant delays in ART initiation and reduced retention in care for patients enrolling in HIV care and treatment programs in East Africa. Consequently, interventions that target alcohol consumption may have a significant impact on the HIV care cascade. © 2020 Patsis et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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