302 research outputs found

    Homeopathic Preparations of Quartz, Sulfur and Copper Sulfate Assessed by UV-Spectroscopy

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    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

    High-field 1H T1 and T2 NMR relaxation time measurements of H2O in homeopathic preparations of quartz, sulfur, and copper sulfate

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    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

    Calibration of parallel kinematics machine-tools using small displacement torsors

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    The accuracy of a machine-tool depends on manufacturing and assembly errors, backlash in the structure and the links, thermal variations, vibrations, and others. The method presented in this paper deals with manufacturing and assembly errors but it can be adapted to other sources of errors. This method uses the concept of Small Displacement Torsors (SDT) to the calibration of parallel kinematics machine-tools. The following hypothesis is made: the defaults of the structure can be modelled by a combination of small displacements of the surfaces in contact. The method consists first of all in modelling each link by a SDT expressed in the local frame of the link (n parameters characterize the defaults of the structure). Then each torsor is written in the frame of the structure where measurements are done. The value of the components of the torsors depends on the pose (position and orientation) of the tool. The relations between the torsors and the tool pose are calculated (N equations connect the parameters to the pose of the tool). Then the pose error is measured in m correctly selected points, so that the n parameters can be identified solving the equation : E=M.D, where E is the vector containing the measured pose errors ; M is the invertible matrix formed with the relations between the torsors and the tool pose ; D is the vector containing the parameters of the torsors. After the identification of vector D, the hypothesis of small displacement must be verified. Finally the pose error of the tool can be calculated in all the working volume. This paper presents the general method based on the Small Displacement Torsors. The links used in machine-tools is modelled by SDT. Then this method is applied to the calibration of the Hita-STT machine-tool, an industrial prototype. The objective is to reach an absolute accuracy of less than 10 microns with a relative accuracy of 5 microns, considering manufacturing and assembly errors in the first calibration phase

    Profibus PC based motion control with application to a new 5 axes parallel kinematics

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    Generally the classical control architecture used to carry out a robot position control is based on a classical industrial motion planner that needs encoders cabling and analog cabling to insure the regulation loop. This work proposes a Profibus PC based control architecture that has a double-originality. The first originality concerns the hardware architecture and the second concerns the software flexibility that allows easiness in implementation, either modification, for controlling parallel robots. The hardware architecture is based upon so-called “intelligent” digital drives and the whole fieldbus hardware

    Homeopathic treatment of children with attention deficit hyperactivity disorder: a randomised, double blind, placebo controlled crossover trial

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    An increasing number of parents turn to homeopathy for treatment of their hyperactive child. Two publications, a randomised, partially blinded trial and a clinical observation study, conclude that homeopathy has positive effects in patients with attention deficit hyperactivity disorder (ADHD). The aim of this study was to obtain scientific evidence of the effectiveness of homeopathy in ADHD. A total of 83 children aged 6-16 years, with ADHD diagnosed using the Diagnostic and Statistical Manual of Mental Disorders-IV criteria, were recruited. Prior to the randomised, double blind, placebo controlled crossover study, they were treated with individually prescribed homeopathic medications. 62 patients, who achieved an improvement of 50% in the Conners' Global Index (CGI), participated in the trial. Thirteen patients did not fulfill this eligibility criterion (CGI). The responders were split into two groups and received either verum for 6 weeks followed by placebo for 6 weeks (arm A), or vice-versa (arm B). At the beginning of the trial and after each crossover period, parents reported the CGI and patients underwent neuropsychological testing. The CGI rating was evaluated again at the end of each crossover period and twice in long-term follow-up. At entry to the crossover trial, cognitive performance such as visual global perception , impulsivity and divided attention, had improved significantly under open label treatment ( P<0.0001). During the crossover trial, CGI parent-ratings were significantly lower under verum (average 1.67 points) than under placebo ( P =0.0479). Long-term CGI improvement reached 12 points (63%, P <0.0001). Conclusion:The trial suggests scientific evidence of the effectiveness of homeopathy in the treatment of attention deficit hyperactivity disorder, particularly in the areas of behavioural and cognitive function

    Patient satisfaction and side effects in primary care: An observational study comparing homeopathy and conventional medicine

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    <p>Abstract</p> <p>Background</p> <p>This study is part of a nationwide evaluation of complementary medicine in Switzerland (Programme Evaluation of Complementary Medicine PEK) and was funded by the Swiss Federal Office of Public Health. The main objective of this study is to investigate patient satisfaction and perception of side effects in homeopathy compared with conventional care in a primary care setting.</p> <p>Methods</p> <p>We examined data from two cross-sectional studies conducted in 2002–2003. The first study was a physician questionnaire assessing structural characteristics of practices. The second study was conducted on four given days during a 12-month period in 2002/2003 using a physician and patient questionnaire at consultation and a patient questionnaire mailed to the patient one month later (including Europep questionnaire).</p> <p>The participating physicians were all trained and licensed in conventional medicine. An additional qualification was required for medical doctors providing homeopathy (membership in the Swiss association of homeopathic physicians SVHA).</p> <p>Results</p> <p>A total of 6778 adult patients received the questionnaire and 3126 responded (46.1%). Statistically significant differences were found with respect to health status (higher percentage of chronic and severe conditions in the homeopathic group), perception of side effects (higher percentage of reported side effects in the conventional group) and patient satisfaction (higher percentage of satisfied patients in the homeopathic group).</p> <p>Conclusion</p> <p>Overall patient satisfaction was significantly higher in homeopathic than in conventional care. Homeopathic treatments were perceived as a low-risk therapy with two to three times fewer side effects than conventional care</p
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