1,504 research outputs found
Homeopathic Preparations of Quartz, Sulfur and Copper Sulfate Assessed by UV-Spectroscopy
Homeopathic preparations are used in homeopathy and anthroposophic medicine. Although there is evidence of effectiveness in several clinical studies, including double-blinded randomized controlled trials, their nature and mode of action could not be explained with current scientific approaches yet. Several physical methods have already been applied to investigate homeopathic preparations but it is yet unclear which methods are best suited to identify characteristic physicochemical properties of homeopathic preparations. The aim of this study was to investigate homeopathic preparations with UV-spectroscopy. In a blinded, randomized, controlled experiment homeopathic preparations of copper sulfate (CuSO(4); 11c-30c), quartz (SiO(2); 10c-30c, i.e., centesimal dilution steps) and sulfur (S; 11×-30×, i.e., decimal dilution steps) and controls (one-time succussed diluent) were investigated using UV-spectroscopy and tested for contamination by inductively coupled plasma mass spectrometry (ICP-MS). The UV transmission for homeopathic preparations of CuSO(4) preparations was significantly lower than in controls. The transmission seemed to be also lower for both SiO(2) and S, but not significant. The mean effect size (95% confidence interval) was similar for the homeopathic preparations: CuSO(4) (pooled data) 0.0544% (0.0260-0.0827%), SiO(2) 0.0323% (-0.0064% to 0.0710%) and S 0.0281% (-0.0520% to 0.1082%). UV transmission values of homeopathic preparations had a significantly higher variability compared to controls. In none of the samples the concentration of any element analyzed by ICP-MS exceeded 100 ppb. Lower transmission of UV light may indicate that homeopathic preparations are less structured or more dynamic than their succussed pure solvent
Sculpturing as an approach to train holistic thinking and perception in the medical curriculum
Contingent Valuation of Mining Land Reclamation in East Germany
Large parts of East German landscapes are formed by lignite mining activities. The mining pits destroy vast areas of the existing cultural landscapes. These areas have to be made re-accessible to society through extensive reclamation projects after mining has been finished. For an appraisal of the social benefits that need to be compared to the costs of these projects the Contingent Valuation Method (CVM) is the method of choice. The CVM measures the willingness to pay of households for such a project. This paper reports the findings of a Con-tingent Valuation study assessing the social utility created by a reclamation project north of the city of Cottbus in Brandenburg, Germany. The goal of the study is threefold. Firstly, the affected population's aggregate willingness to pay for the planned reclamation project is cal-culated; it amounts to 2.7 mil. Euro per year. Secondly, the determinants of this willingness to pay are analyzed. Apart from the expected positive impact of income on willingness to pay we find that it is also influenced by people's recreational activities, their general attitudes to-wards public spending and by their concerns about the economic situation. Thirdly, the study explores methodological specifics of an application of the CVM to Germany, especially in East Germany, by focusing on the appropriate design of the willingness to pay question which is an important feature still controversially discussed in the literature.contingent valuation;
High-field 1H T1 and T2 NMR relaxation time measurements of H2O in homeopathic preparations of quartz, sulfur, and copper sulfate
Quantitative meta-analyses of randomized clinical trials investigating the specific therapeutic efficacy of homeopathic remedies yielded statistically significant differences compared to placebo. Since the remedies used contained mostly only very low concentrations of pharmacologically active compounds, these effects cannot be accounted for within the framework of current pharmacology. Theories to explain clinical effects of homeopathic remedies are partially based upon changes in diluent structure. To investigate the latter, we measured for the first time high-field (600/500MHz) 1H T1 and T2 nuclear magnetic resonance relaxation times of H2O in homeopathic preparations with concurrent contamination control by inductively coupled plasma mass spectrometry (ICP-MS). Homeopathic preparations of quartz (10c-30c, n = 21, corresponding to iterative dilutions of 100−10-100−30), sulfur (13x-30x, n = 18, 10−13-10−30), and copper sulfate (11c-30c, n = 20, 100−11-100−30) were compared to n = 10 independent controls each (analogously agitated dilution medium) in randomized and blinded experiments. In none of the samples, the concentration of any element analyzed by ICP-MS exceeded 10ppb. In the first measurement series (600MHz), there was a significant increase in T1 for all samples as a function of time, and there were no significant differences between homeopathic potencies and controls. In the second measurement series (500MHz) 1year after preparation, we observed statistically significant increased T1 relaxation times for homeopathic sulfur preparations compared to controls. Fifteen out of 18 correlations between sample triplicates were higher for controls than for homeopathic preparations. No conclusive explanation for these phenomena can be given at present. Possible hypotheses involve differential leaching from the measurement vessel walls or a change in water molecule dynamics, i.e., in rotational correlation time and/or diffusion. Homeopathic preparations thus may exhibit specific physicochemical properties that need to be determined in detail in future investigation
Charge separation and carrier dynamics in donor-acceptor heterojunction photovoltaic systems
Electron transfer and subsequent charge separation across donor-acceptor heterojunctions remain the most important areas of study in the field of third- generation photovoltaics. In this context, it is particularly important to unravel the dynamics of individual ultrafast processes (such as photoinduced electron transfer, carrier trapping and association, and energy transfer and relaxation), which prevail in materials and at their interfaces. In the frame of the National Center of Competence in Research “Molecular Ultrafast Science and Technology,” a research instrument of the Swiss National Science Foundation, several groups active in the field of ultrafast science in Switzerland have applied a number of complementary experimental techniques and computational simulation tools to scrutinize these critical photophysical phenomena. Structural, electronic, and transport properties of the materials and the detailed mechanisms of photoinduced charge separation in dye- sensitized solar cells, conjugated polymer- and small molecule-based organic photovoltaics, and high-efficiency lead halide perovskite solar energy converters have been scrutinized. Results yielded more than thirty research articles, an overview of which is provided here
Proton pump inhibitor prescription in nursing home residents : prevalence, appropriateness, and associated factors - a secondary data analysis from three German regions and the impact of guideline recommendations
Despite reliable evidence of adverse drug effects, the substantially increased prescription rates of proton pump inhibitors (PPIs) remain at a high level. This study analyzed the appropriateness of PPI prescriptions among residents of nursing homes in three regions of Germany. Baseline data of a cluster-randomized controlled trial were used to determine the prevalence of PPI prescriptions, the validity of indications, and the adequacy of the prescribed dosages according to 1. their drug approvals and 2. valid recommendation guidelines. Regression analyses were conducted to assess associated factors. A total of 437 residents in 37 nursing homes were included (mean age 83 ± 9.2 years, 72% women). The PPI prescription prevalence was 44% (n = 193). In 52/193 (27%) there was no adequate indication, and in 54 (39%) of 138 indicated PPI prescriptions it was overdosed. Yet, in only less than one-third (28%) of “adequate” prescriptions, the indication was according to the PPI approvals, whereas the majority (72%) were off-label indications in line with valid guideline recommendations. Non-indicated PPI prescription was associated with the total number of prescribed drugs (OR 1.32; 95% CI 1.18–1.62; p = 0.013). There were no associations with age, level of care dependency, cognitive impairment, prescription of psychotropic drugs, number of chronic diseases, number of physicians’ consultations, or study region. To conclude, in 55%, the high prescription prevalence among residents was either not indicated or overdosed. In total, only 20% (39/193) of cases of PPI use complied with the approved indications. There is a need for quality control of 1. PPI administration in German nursing homes, and 2. of guideline recommendations expanding the off-label PPI use by 72% within the indication scale, predominantly from wide prescription for low-dose ASA
Systemic physiology augmented functional near-infrared spectroscopy: a powerful approach to study the embodied human brain.
In this Outlook paper, we explain why an accurate physiological interpretation of functional near-infrared spectroscopy (fNIRS) neuroimaging signals is facilitated when systemic physiological activity (e.g., cardiorespiratory and autonomic activity) is measured simultaneously by employing systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS). The rationale for SPA-fNIRS is twofold: (i) SPA-fNIRS enables a more complete interpretation and understanding of the fNIRS signals measured at the head since they contain components originating from neurovascular coupling and from systemic physiological sources. The systemic physiology signals measured with SPA-fNIRS can be used for regressing out physiological confounding components in fNIRS signals. Misinterpretations can thus be minimized. (ii) SPA-fNIRS enables to study the embodied brain by linking the brain with the physiological state of the entire body, allowing novel insights into their complex interplay. We envisage the SPA-fNIRS approach will become increasingly important in the future
The Role of Systemic Physiology in Individual Hemodynamic Responses Measured on the Head Due to Long-Term Stimulation Involving Colored Light Exposure and a Cognitive Task: An SPA-fNIRS Study
In our previous investigations using systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS) neuroimaging, we found larger variability between subjects in changes of cerebral hemodynamics and oxygenation induced by an intricate experimental paradigm involving colored light exposure and a cognitive task. We aimed to investigate the role the activity of the systemic physiology has on individual variations in the fNIRS data. Thirty-two healthy subjects (17 female, 15 male and age: 25.5 ± 4.3 years) were exposed to blue and red light for 9 min (colored light exposure, CLE) while performing a verbal fluency task (VFT). We found that (i), at the group level, the visual cortex showed a stronger deoxyhemoglobin concentration response during blue light exposure than during red light exposure, and (ii) this relationship was influenced by individually different baseline blood pressure values. Furthermore, we found other correlations between changes in fNIRS signals and changes in systemic physiology. Our study demonstrates the usefulness and necessity of the SPA-fNIRS approach to gain insights into the individual variability of hemodynamic responses measured with fNIRS, especially in the case of an intricate experimental paradigm (i.e., CLE-VFT) as used in our study
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