Investigation of molecular dimers by ensemble and single molecule spectroscopy

We have investigated molecular dimers with different electronic coupling strengths by bulk and single molecule spectroscopy. In one of the dimers the two monomers (perylene-monoimide) are directly connected via a single bond while in the other one they are separated by the benzil motif. The close proximity of the monomers in the first case gives rise to excitonic band splitting which is clearly observable in the bulk absorption spectra. For the benzil structure the electronic interactions are governed by Förster-type energy hopping between the monomers. Fluorescence intensity trajectories at the single molecule level show one-step and two-step bleaching behaviour which appears to be very similar for both dimers. However, emission spectra recorded simultaneously with the trajectories indicate spectral changes which allow to distinguish between weakly and strongly coupled dimers. In the latter case the spectral shape changes significantly when excitonic coupling has been lifted because of photochemical transformation of one of the monomers

Using of polypropylene fibers for cleaning of industrial waste water from the fat-soluble organic pollutants

The paper shows the perspective of using methods of ion implantation and microwave irradiation for modifying polypropylene fiber by iron (II), lanthanum (II) and iron metal ions. It was shown that this method is very useful in order to obtain a material with a high photocatalytic activity for extracting liposoluble dyes from non-aqueous media under UV and visible light

Self-reported practices and emotions in prescribing opioids for chronic, noncancer pain: A cross-sectional study of German physicians

Background: The pressure on physicians when a patient seeks pain relief and their own desire to be self-effective may lead to the prescription of strong opioids for chronic noncancer pain (CNCP). This study, via physician self-reporting, aims to identify and measure (i) physician adherence to national opioid prescribing guidelines and (ii) physician emotions when a patient seeks a dosage increase of the opioid. Methods: Within a cross-sectional survey—conducted as part of a randomized controlled online intervention trial (ERONA)—600 German physicians were queried on their opioid prescribing behavior (choice and formulation of opioid, indications) for CNCP patients and their emotions to a case vignette describing a patient seeking an opioid dosage increase without signs of objective deterioration. Results: The prescription of strong opioids in this study was not always in accordance with current guidelines. When presented with a scenario in which a patient sought to have their opioid dose increased, some physicians reported negative feelings, such as either pressure (25%), helplessness (25%), anger (23%) or a combination. The risk of non-guideline-compliant prescribing behavior using the example of ultrafast-acting fentanyl for CNCP was increased when negative emotions were present (OR: 1.7; 95%-CI: 1.2–2.6; p = 0.007) or when sublingual buprenorphine was prescribed (OR: 15.4; 95%-CI: 10.1–23.3; p < 0.001). Conclusions: Physicians’ emotional self-awareness represents the first step to identify such direct reactions to patient requests and to ensure a responsible, guideline-based opioid prescription approach for the long-term well-being of the patient

a randomized controlled trial

Diurnal carbohydrate and fat distribution modulates glycaemic control in rodents. In humans, the optimal timing of both macronutrients and its effects on glycaemic control after prolonged consumption are not studied in detail. In this cross-over trial, 29 non-obese men were randomized to two four-week diets: (1) carbohydrate-rich meals until 13.30 and fat-rich meals between 16.30 and 22.00 (HC/HF) versus (2) inverse sequence of meals (HF/HC). After each trial period two meal tolerance tests were performed, at 09.00 and 15.40, respectively, according to the previous intervention. On the HF/HC diet, whole-day glucose level was increased by 7.9% (p = 0.026) in subjects with impaired fasting glucose and/or impaired glucose tolerance (IFG/IGT, n = 11), and GLP-1 by 10.2% (p = 0.041) in normal glucose-tolerant subjects (NGT, n = 18). Diet effects on fasting GLP-1 (p = 0.009) and PYY (p = 0.034) levels were observed in IFG/IGT, but not in NGT. Afternoon decline of glucose tolerance was more pronounced in IFG/IGT and associated with a stronger decrease of postprandial GLP-1 and PYY levels, but not with changes of cortisol rhythm. In conclusion, the HF/HC diet shows an unfavourable effect on glycaemic control in IFG/IGT, but not in NGT subjects. Consequently, large, carbohydrate-rich dinners should be avoided, primarily by subjects with impaired glucose metabolism

Reduced postprandial energy expenditure and increased exogenous fat oxidation in young woman after ingestion of test meals with a low protein content

<p>Abstract</p> <p>Background</p> <p>Macronutrient composition of diets can influence energy balance in humans. We tested the hypothesis whether low protein content in single meals may induce lower values of energy expenditure (EE) and fat oxidation (FO) as compared to adequate protein content.</p> <p>Methods</p> <p>Indirect calorimetry was combined with a breath test using naturally ¹³C-enriched corn oil to differentiate between postprandial exogenous and endogenous FO. Young women ingested single meals containing either 3.9% (low protein, LP) or 11.4% (adequate protein, AP) of total energy (~3100 kJ) as protein.</p> <p>Results</p> <p>Postprandial EE was 160 kJ/6 h lower (p < 0.01) after LP meals and diet induced thermogenesis (DIT) increased less (p < 0.001) as compared to AP meals. Total postprandial FO was not significantly different between meals (~17 g/6 h). However, exogenous postprandial FO was significantly (p < 0.01) higher (4.28 ± 1.57 g/6 h) after exposure to LP meals as compared to AP meals (1.87 ± 1.00 g/6 h). Less than 10% of ingested fat (50 g) was oxidized in the postprandial phase. The overall postprandial fat balance was approximately + 33 g.</p> <p>Conclusion</p> <p>Breath tests using naturally ¹³C-labeled corn oil mirror exogenous FO. Low protein meals resulted in reduced postprandial EE and increased exogenous FO as compared to adequate protein meals without differences in total FO.</p