Without a detection limit a negative finding is hard to interpret. The project described in this article used a high-sensitivity NMR method to test this possibility, i.e., do remedies made in water contain low concentrations of long-lived non-dynamic regions of structured H-bonding? A good starting point was to quantify the detection limits of previous studies and of the present study. Therefore NMR spectroscopy is a good method for testing the cluster hypothesis only if, as part of the hypothesis, we postulate that clusters are non-dynamic or that dwell times are on the order of several milliseconds or longer. Dwell times are considerably shorter than 10 -3 sec for a variety of processes, such as ion solvation and protein association. If the dwell time is shorter than 10 -3 sec or so, NMR will not be able to "see" it because the chemical shift will be the average over some milliseconds, and the discrete signals will blend back in with the ambient water signal. The key concept is a parameter called "dwell time", which is the average time a molecule spends in a cluster. A cluster whose components exchange with the ambient solvent would be called "dynamic". Exchanges of surface hydrogens could also occur rapidly without losing the cluster geometry. If only one molecule at a time leaves a cluster and it is replaced quickly by another solvent molecule, then the pattern or geometry of the cluster could be sustained without indefinitely tying up any individual solvent molecules. A trickier but more believable hypothesis is that solvent molecules cycle back and forth between the ambient solvent and the clusters. One version of the "cluster theory" posits that once a solvent molecule becomes part of a stable cluster it will stay in that cluster indefinitely. "Unexplained" discrete peaks have never been reported in NMR spectroscopy studies of remedies, but we wondered if this might be because cluster concentrations are very small and the methodology has been insufficiently sensitive to detect them.Ī technical but relevant point must be introduced here. There would be one discrete signal or peak for each symmetry-distinct H in the cluster, along with the expected large peak at 4.8 ppm for the ambient water. If this hypothesis is correct, then the H's making up H-bonds in the stable clusters would experience a bonding environment different from that of the ambient solvent, and they should generate a separate signal on the NMR spectrum. One hypothesis to explain how UD remedies might be different from controls states that remedies contain long-lived stable clusters of solvent molecules that are not present in controls. It should be noted that all studies had methodological weaknesses according to the criteria developed by Becker-Witt et al. However Aabel and coworkers' recent study found no differences between remedies and controls. Of these nine, eight reported finding differences between remedies and controls when focusing on the relative height, chemical shift, or width of one or more of the peaks due to H's in the solvent. identified 18 published articles on the use of NMR to study remedies, of which 9 projects used NMR spectroscopy. Recent literature reviews by Baumgärtner and by Becker-Witt et al. Chemical shifts are measured in units of parts per million (ppm) deviation from a reference shift. The chemical shift of a proton in a molecule in a sample reflects the (time-averaged) amount of magnetic shielding provided by the electrons making up the covalent or hydrogen bond(s) in which the proton participates, with greater electron density generally correlating with lower chemical shift numbers. There are also more complex applications of NMR such as imaging and two-dimensional NMR that are not relevant to the study of discrete remedy samples. In analytical studies, also called spectroscopy, the results are displayed as a graph or spectrum plotting concentration against a variable called chemical shift. The term "NMR" encompasses both solvent mobility studies (results are given as a pair of relaxation times denoted T 1 and T 2) and analytical studies. Proton nuclear magnetic resonance ( 1H-NMR, or simply NMR) is among the techniques that have been used to look for differences between remedies and control samples. Experiments attempting to measure or document solvent alteration through direct study of the physical and chemical properties of remedies have so far failed to yield any independently replicated positive effects. A widely accepted premise of those doing research in this field is that if remedies are more than placebos, then the process of making remedies by alternating dilution and succussion must alter the solvent, encoding in it a "memory" or "information" that biological systems can detect. The mechanism of action of homeopathic remedies has baffled practitioners and scientists for two centuries.
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