Synthesis and antibacterial characterization of sustainable nanosilver using naturally-derived macromolecules.

Greener nanosynthesis utilizes fewer amounts of materials, water, and energy; while reducing or replacing the need for organic solvents. A novel approach is presented using naturally-derived flavonoids including Quercetin pentaphosphate (QPP), Quercetin sulfonic acid (QSA) and Apigenin Triphosphate (ATRP). These water soluble, phosphorylated flavonoids were utilized both as reducing agent and stabilizer. The synthesis was achieved at room temperature using water as a solvent and it requires no capping agents. The efficiency of the resulting silver nanoparticle synthesis was compared with naturally-occurring flavonoid such as Quercetin (QCR). Results show that QCR reduced Ag(+) faster followed by QPP, QSA and ATRP respectively. This is the first evidence of direct utilization of QCR for synthesis of silver nanoparticles (AgNPs) in water. The percentage conversion of Ag(+) to Ag(0) was determined to be 96% after 35min. The synthesized nanoparticles were characterized using Transmission electron microscopy (TEM), Energy dispersive absorption spectroscopy (EDS), UV-vis spectroscopy, High resolution TEM (HR-TEM) with selected area electron diffraction (SAED). The particle sizes ranged from 2 to 80nm with an average size of 22nm and in the case of ATRP, the nanoparticle shapes varied from spherical to hexagonal with dispersed particle size ranging from 2 to 30nm. Crystallinity was confirmed by XRD and the SAED of (111), (200), and the fringes observed in HRTEM images. Results were in agreement with the UV resonance peaks of 369-440nm. The particles also exhibit excellent antibacterial activity against Staphylococcus epidermidis, Escherichia coli and Citrobacter freundii in water.

"Ultra High Dilution 1994" revisited 2015--the state of follow-up research.

BACKGROUND: The "Ultra High Dilution 1994" project was an endeavour to take stock of the findings and theories on homeopathic extreme dilutions that were under research at the time in areas of biology, biophysics, physics and medicine. The project finally materialized into an anthology assembling contributions of leading scientists in the field. Over the following two decades, it became widely quoted within the homeopathic community and also known in other research communities. The aim of the present project was to re-visit and review the 1994 studies from the perspective of 2015. METHOD: The original authors from 1994 or close laboratory colleagues were asked to contribute papers covering their research efforts and learnings in the period from 1994 up to 2015. These contributions were edited and cross-referenced, and a selection of further contributions was added. RESULTS: About a dozen contributions reported on follow-up experiments and studies, including further developments in theory. Only few of the models that had seemed promising in 1994 had not been followed up later. Most models presented in the original publication had meanwhile been submitted to intra-laboratory, multicentre or independent scrutiny. The results of the follow-up research seemed to have rewarded the efforts. Furthermore, contributions were provided on new models that had been inspired by the original ones or that may be candidates for further in-depth ultra high dilution (UHD) research. CONCLUSION: The project "Ultra High Dilution 1994 revisited 2015" is the latest output of what might be considered the "buena vista social club" of homeopathy research. However, it presents new developments and results of the older, established experimental models as well as a general survey of the state of UHD research.

Experimental physical methods and theories--then and now.

INTRODUCTION: A first evaluation of fundamental research into the physics and physiology of Ultra high dilutions (UHDs) was conducted by the author in 1994(1). In this paper we revisit methods and theories from back then and follow their paths through their evolution and contribution to new knowledge in UHD research since then. METHOD: Physical methods and theories discusses in our anthology on UHD in 1994(1) form the basis for tracing ideas and findings along their path of further development and impact on new knowledge in UHD. RESULTS: Experimental approaches to probe physical changes in homeopathic preparations have become more sophisticated over past two decades, so did the desire to report results to a scientific standard that is on par with those in specialist literature. The same cannot be said about underlying supporting theoretical models and simulations. CONCLUSION: Grant challenges in science often take a more targeted and more concerted approach to formulate a research question and then look for answers. A concerted effort to focus on one hypothesized physical aspect of a well-defined homeopathic preparation may help aligning experimental methods with theoretical models and, in doing so, help to gain a deeper understanding of the whole body of insights and data produced.

Publications on experimental physical methods to investigate ultra high dilutions--an assessment on quality.

INTRODUCTION: Our first evaluation of fundamental research into the physics and physiology of Ultra High Dilution (UHD) was conducted in 1994. Since then, in 2003, Becker-Witt et al. conducted a more systematic evaluation of the literature and established the Score for Assessment of Physical Experiments on Homeopathy (SAPEH). While this evaluation focused on experimental methodologies, Stock-Schröer et al., in 2009, formulated a detailed guideline for authors on Reporting Experiments in Homeopathic Basic research (REHBaR) to promote a high standard in research as well as in its communication in scientific literature. METHOD: In this paper, we evaluate publications on basic research into the physics of UHD since the decade following the presentation of the SAPEH score (2004-2014), and present the state of progress in this field. RESULTS: Fundamental research into the physics of UHD has been reported at a steady rate over the past 60 years. Reported research of high quality as per SAPEH scoring appears to be still the exception rather than standard. CONCLUSION: Considering the importance of a fundamental understanding of what makes a UHD preparation, results of this study suggest that it may be beneficial to this field of fundamental research if grant challenges are approached in strategic way similar to other grant challenges in science.

Observations on entanglement, non-locality and ultra-high dilutions.

INTRODUCTION: Fundamental research into the scientific basis of the manufacture of ultra-high dilutions and their working in applications has evolved over the past twenty years since our last critical analysis of the field was published in 1994. New contenders from the realm of physics (entanglement, non-locality) have entered the scene. The vast majority within the community of the application of ultra-high dilutions are not physicists. This paper attempts to elucidate the concepts of entanglement, non-locality and their application in ultra-high dilution research (UHD). METHOD: A selected study on the activity of fundamental research into UHD is performed to gain insight into trends of development activity of fundamental research in this area. In an attempt to nurture further development of theoretical models in fundamental research in UHD, an attempt is made to made recent theoretical concepts more accessible to the larger community including practitioners, policy makers and beneficiaries of UHD. RESULTS: Fundamental research in UHD had a period of prolific activity and recognition at the turn of the millennium until about ten years ago. Since then, research output as well as its recognition receded sharply suggesting that a period of reflection and consolidation may be in progress. CONCLUSION: The study and the knowledge gained from more recent theoretical models in UHD and entanglement suggest that there may be some benefit in stocktaking of what we really know about the fundamental workings of UHD as well as identifying or developing models that include measurable predictors that go beyond metaphorical descriptors.

Update on preliminary elements of a theory of ultra high dilutions.

INTRODUCTION: The different mechanisms: A. of the interaction between the molecular mother substance and the solvent water or ethanol B. of the storage of molecule-specific information in the solvent. C. the physiological basis of the sensitivity of the living organism towards an ultra high dilution (UHD). D. the mechanism of the interaction of the test dilution with the organism are largely unknown. Several ideas have been postulated, and experiments to test them carried out in physics and in biology. METHOD: The authors revisited a 1994 contribution on 'preliminary elements of a theory on UHDs' and updated it with regard to more recent literature and research findings. RESULTS: Although the experimental basis can still be questioned in most cases, remarkable fundamental observations have been made to explain the effects of UHDs. For some topics in question, it appears that information specific properties of the diluted substance to be transferred is stored by means electromagnetic fields. The interaction between the UHD and the organism seems to be electromagnetic in nature. The transmission of information from (bio-)molecules to the UHD is of special interest. Again, electromagnetic actions and vector potential fields appear to be implicated. CONCLUSION: The mechanisms of information storage and transfer in UHDs are far from fully understood, but progress has been made at experimental and theoretical levels.

Fibrillation of ß amyloid peptides in the presence of phospholipid bilayers and the consequent membrane disruption.

Fibrillation of ß amyloid (Aß) peptides and the accumulation of amyloid plaques are considered as an important clinical hallmark to identify Alzheimer's disease (AD). The physiological connection between Aß plaques and the disruption of neuronal cells has not been clearly understood. One hypothesis to explain the Aß neurotoxicity is that the fibrillation process induces disruption to the cellular membrane. We studied the Aß fibrillation process in two biologically relevant conditions with the peptide either pre-incorporated into or externally added to the synthetic phospholipid bilayers. These two sample preparation conditions mimic the physiological membrane proximities of Aß peptides before and after the enzymatic cleavage of amyloid precursor protein (APP). Using thioflavin T (ThT) fluorescence and transmission electron microscopy (TEM), we were able to monitor the kinetics and morphological evolution of fibril formation, which was highly sensitive to the two sample preparation protocols. While the external addition protocol generates long and mature fibrils through normal fibrillation process, the pre-incubation protocol was found to stabilize the immature protofibrils. Fluorescence spectroscopy studies with doubly-labeled phospholipids indicated that there may be a lipid uptake process associated with the fibril formation. Solid state nuclear magnetic resonance (NMR) spectroscopy provided evidence for high resolution structural variations in fibrils formed with different protocols, and in particular the stabilization of long-range contact between N- and C-terminal ß strands. In addition, disruption of phospholipid bilayers was supported by measurements with ³¹P chemical shifts and relaxation time constants.

Secrets of solid state and aqueous solution structures of [Ni(tmdta)](2-).

The molecular structures of Li2[Ni(tmdta)]·5H2O (1a, tmdta = trimethylenediaminetetraacetate), {C(NH2)3}2[Ni(tmdta)]·6H2O (1b), and {Ni(H2O)6}[Ni(tmdta)]·2H2O (2a) have been determined. The central trimethylenediamine chelate ring shows half-chair (hc) geometries in 1a and 1b, while a twist-boat (tb) conformation is encountered in 2a. The coexistence of tb and hc forms in the solid state prompted us to elucidate the existence of a tb ⇌ hc equilibrium in aqueous solution. Evaluation of the data from solid state vibrational spectra (Raman and IR) for the hc and tb forms showed excellent agreement with simulated spectra obtained with DFT computations (TPSSh/TZVP). This outstanding matching between theory and experiment enabled us to build composite spectra with varying hc:tb ratios. Comparison of these results with Raman and IR spectra recorded for [Ni(tmdta)](2-) in aqueous solution revealed that simulated Raman and IR spectra with a hc:tb ratio = 2:3 match the solution spectra in an accurate way. This equilibrium ratio enabled us to compute (13)C NMR sifts for the paramagnetic solution spectrum of [Ni(tmdta)](2-) based on the relative contributions by hc and tb fractions. This leads to computed shifts that agree closely with the experimental ones. Also, the kinetics of the skeleton dynamics could be estimated quantitatively by temperature-dependent (13)C NMR spectroscopic measurements. An interesting effect encountered for the very first time here concerns a drastic intensity difference of the 10Dq band ((3)A2g → (3)T2g(F) transition) in solid state electronic spectra of tb vs hc isomers, where the intensity of this band in the case of the hc form is much lower than that of the tb conformer and thus more similar to the case of the usual Ni(II) chromophore in octahedral environment. The equilibrium constants for complex formation and protonation of Ni(II)-tmdta at low pH have been estimated by pH-dependent UV-vis titration experiments. Correlation of these data with those of Ni(II)-edta and related 3d M(II) edta and tmdta complexes allow important conclusions on the consequences resulting from extending the central diamine ring in the ligand by one methylene group in terms of both complex and protolytic stability for edta vs tmdta complexes.

Adsorption of organophosphates into microporous and mesoporous NaX zeolites and subsequent chemistry.

Due to the neurotoxicity of organophosphate (OP) pesticides and nerve agents synthesized as military or terror agents, their safe destruction and disposal is of considerable current importance. A representative OP, trimethyl phosphate (TMP), was adsorbed onto NaX zeolite, two mesoporous modifications, and a low-silica X zeolite. The nucleophilic chemical reactions of TMP with the zeolites were investigated by solid-state 13C and 31P nuclear magnetic resonance (NMR) and the solvent extracts by 1H, 13C, and 31P NMR. Nucleophilic substitution and subsequent hydrolysis reaction schemes are proposed. All of the zeolites have similar TMP decomposition yields, supporting the hypothesis that slow or incomplete diffusion of TMP in the microporous zeolite regions limits TMP decomposition.

Synthesis and Characterization of Tetrahydrofurfurylcyclopentadienyl Molybdenum Tricarbonyl Dimer: Evidence for 19-Electron Intramolecular "Solvento" Interactions.

The synthesis and characterization of a THF pendant, dimeric Mo cyclopentadienyl complex is reported and the structure characterized by NMR, FTIR, and UV-vis spectroscopies. The dimer was found to undergo metal-metal bond homolysis under either photochemical or electrochemical conditions to yield an odd-electron complex. Cyclic voltammetry under varying scan rate conditions from 25 to 10 000 mV/s demonstrates a dynamic equilibrium process that we assign to the formation of either an intramolecular 19-electron (18 + delta) complex or a bare 17-electron complex. Photolysis of the dimer in room temperature solution could be monitored as a loss of the dpi-dsigma transition at 503 nm by transient absorption spectroscopy. The recovery of the transient absorption signal at 410 nm follows first-order kinetics at a rate of 5 x 10(3) s(-1).