Ultradilute Solution Research Articles

Understanding the Electrochemical Extraction of Lithium from Ultradilute Solutions.

The electrochemical extraction of lithium (Li) from aqueous sources using electrochemical means is a promising direct Li extraction technology. However, to this date, most electrochemical Li extraction studies are confined to Li-rich brine, neglecting the practical and existing Li-lean resources, with their overall extraction behaviors currently not fully understood. More still, the effect of elevated sodium (Na) concentrations typically found in most Li-lean water sources on Li extraction is unclear. Hence, in this work, we first understand the electrochemical Li extraction behaviors from ultradilute solutions using spinel lithium manganese oxide as the model electrode. We discovered that Li extraction depends highly on the Li concentration and cell operation current density. Then, we switched our focus on low Li to Na ratio solutions, revealing that Na can dominate the electrostatic screening layer, reducing Li ion concentration. Based on these understandings, we rationally employed pulsed electrochemical operation to restructure the electrode surface and distribute the surface-adsorbed species, which efficiently achieves a high Li selectivity even in extremely low initial Li/Na concentrations of up to 1:20,000.

High-Performance FAU Zeolite Membranes Derived from Nano-Seeds for Gas Separation.

In this study, high-performance FAU (NaY type) zeolite membranes were successfully synthesized using small-sized seeds of 50 nm, and their gas separation performance was systematically evaluated. Employing nano-sized NaY seeds and an ultra-dilute reaction solution with a molar composition of 80 Na2O: 1Al2O3: 19 SiO2: 5000H2O, the effects of synthesis temperature, crystallization time, and porous support (α-Al2O3 or mullite) on the formation of FAU membranes were investigated. The results illustrated that further extending the crystallization time or increasing the synthesis temperature led to the formation of a NaP impurity phase on the FAU membrane layer. The most promising FAU membrane with a thickness of 2.7 µm was synthesized on an α-Al2O3 support at 368 K for 8 h and had good reproducibility. The H2 permeance of the membrane was as high as 5.34 × 10-7 mol/(m2 s Pa), and the H2/C3H8 and H2/i-C4H10 selectivities were 183 and 315, respectively. The C3H6/C3H8 selectivity of the membrane was as high as 46, with a remarkably high C3H6 permeance of 1.35 × 10-7 mol/(m2 s Pa). The excellent separation performance of the membrane is mainly attributed to the thin, defect-free membrane layer and the relatively wide pore size (0.74 nm).

Size separation of sodium dodecyl sulfate-proteins by capillary electrophoresis in dilute and ultra-dilute dextran solutions.

SDS capillary gel electrophoresis is a widely used in the biopharma and the biomedical fields for rapid size separation of proteins. However, very limited information is available on the use of dilute and ultra-dilute sieving matrices for SDS-protein analysis. Here, background electrolytes (BGEs) containing 1%-0% dextran were used in borate-based BGE to separate a protein sizing ladder (PSL)≤225kDa and the intact and subunit forms of a therapeutic monoclonal antibody (mAb). The separation performance for the PSL and mAb components differed significantly with decreasing dextran concentration. Ferguson and reptation plots were used to elucidate the separation mechanism. Highly diluted dextran solutions resulted in linear Ferguson plots for both solute types (cf. Ogston theory) in spite of this model assumes a rigid pore structure, thus cannot describe the separation mechanism in ultra-dilute polymer solutions with no reticulations. The saddle differences between the resolution of the PSL and the intact/subunit mAb forms in ultra-dilute dextran-borate matrices suggested the importance of shape selectivity, manifested by the adequate separation of the SDS covered intact as well as light and heavy chain subunits of the therapeutic mAb even at zero dextran concentration.

Velocity field distribution control in antisolvent flow realizing highly stable and efficient perovskite nanocrystals

Achieving highly stable and efficient perovskite nanocrystals (NCs) without applying functional additives or encapsulation, particularly sustaining the stability in ultra-dilute solution, is still a formidable challenge. Here, we show the FAPbI3 perovskite NCs with achieved ∼100 % photoluminescence quantum yield (PLQY) and low defect density (∼0.2 cm−3 per NCs), which is obtained by controlling the velocity field distribution of antisolvent flow in ligand-assisted reprecipitation process. The NCs show incredible reproducibility with narrow deviation of PLQY and linewidth between batch by batch, as well as remarkable stability of maintaining over 80 % PLQY, either in an ultra-diluted solution (9.3 × 10-6 mg/mL), or storing in ambient condition after 90 days with concentration of 0.09 mg/mL. The results in this work demonstrate the interplay of fluid mechanics and crystallization kinetics of perovskite, which pioneers a novel and unprecedent understanding for improving the stability of perovskite NCs for efficient quantum light source.

A cyclopolymer incorporating tetraphenylethene groups in its cyclic repeating units

Although incorporating AIEgens in versatile polymer topological structures is of high interest, cyclopolymers incorporating AIEgens have rarely been reported yet. In this work, a cyclopolymer incorporating tetraphenylethene groups in its cyclic repeating units (pTPE-dMMA) is synthesized in comparison with a linear polymer with tetraphenylethene pendant side groups (pTPE-MMA). The PLQY of pTPE-dMMA in the solid state is 50.35%, higher than that of pTPE-MMA (32.06%) in the solid state. The AIE behaviors of both pTPE-dMMA and pTPE-MMA in solutions are investigated. Because of the ring-constraint, the PL color of AIE cyclopolymer is not dependent on aggregation, while the PL intensity increases as the increased cyclopolymer concentration or aggregation. Even in an ultra-dilute solution (0.002 mg/mL), pTPE-dMMA exhibits significant AIE performance as the water fraction is increased. The enhanced AIE properties of pTPE-dMMA are ascribed to the ring constraint in the side groups and dense intra-/inter-molecular stacking. This work is useful not only for the designing novel AIE materials or fluorescent dyes, but also for understanding the structure–property–function relationships of a cyclopolymer.

Dynamization-induced nanosolutes (DINS) in ultra-dilute solutions. Analysis on homeopathic dilute capsules below and over the Avogadro's number

article: Dynamization-induced nanosolutes (DINS) in ultra-dilute solutions. Analysis on homeopathic dilute capsules below and over the Avogadro’s number - Gazzetta Medica Italiana - Archivio per le Scienze Mediche 2022 April;181(4):271-7 - Minerva Medica - Journals

NMR analysis: potential and challenges as a homeopathic basic research tool

Background: Homeopathic ultra-diluted solutions surpass the threshold of matter dispersion and, consequently, their chemical constitution is similar to inert solvent. Nevertheless, randomized clinical trials have shown that the clinical effects of these homeopathic medicines are superior to placebo1. Nuclear magnetic resonance (NMR) is one of the most promising techniques to detect physicochemical alterations induced by homeopathic procedures2,3. Aims: To investigate T2 NMR relaxation times of Zincum metallicum and lactose dynamized samples. Methodology: Zincum metallicum samples were ground until 6dH using lactose as an excipient. Subsequently, these samples were dynamized with ultrapure water to produce 8dH, 9dH, 10dH, and 11dH. Lactose dynamized samples (6dH-11dH) were used as control. Aliquots of 540µl of each sample were diluted with 60µl of deuterated water (D2O) in 5mm tubes. The analyses were carried out in Bruker Ascend TM 500MHZ spectrometer at 288 K. Results and discussion: The Zincum metallicum and lactose T2 relaxation times were very similar, except for Zincum metallicum 8dH, which presented a value of 1.226 in comparison to 1.036 of lactose 8dH. The following T2 values were registered: 1.287 - 9dH; 1.413 - 10dH; 1.467 - 11dH, and 1.303 - 9dH; 1.400 – 10dH; 1.350 -11dH, for Zincum metallicum and lactose, respectively. The differences detected in 8dH samples are probably due to the presence of lactose in the first dilution step, in which 1 part of the 6dH triturated mixture was diluted in 9 parts of water, to prepare 7dH. Following this homeopathic procedure, 8dH solutions remain around 1% of lactose which could be influenced by the T2 values registered. Conclusion: These preliminary results showed the possibility to apply the NMR technique to evaluate the influence of dynamization in the relaxation parameters. Further studies should be carried out with other potencies and/or other homeopathic substances, in addition to the evaluation of T1 and the T1/T2 parameters, as previously described by other groups.

Teaching and practice in Homeopathy via pharmacobotany and pathophysiology

Background: Semiology, Clinical Pathophysiology, Phytotherapy and Homeopathy were taught through active methodology by the Moodle platform (HL) also using apps for monitoring injuries through SAPB site, building rationality for the external topic use of homeopathic and herbal medicines. At the 7th Infirmary of General Hospital Santa Casa de Misericordia in Rio de Janeiro, the clinical medical team of the Benoit Mure Nucleus of Assistance Teaching and Research, made a medicinal plant garden with the agricultural/environmental educator, and community ethnical leaders. Undergraduate students from UNIFASE/FMP Academic League of Physiology and Pathophysiology planted Calendula Officinalis seedlings, destined to research in pharmacobotany and to be in touch with pharmacotechnical prepares. Aims: To follow-up the study since from seedling of Calendula Officinalis till to prepare of HUD. Methodology: To prepare medicinal garden: plant seedlings of Calendula offin accordance with good agricultural techniques. At first: Three seeds in ten pots, made in triplicate (N = 90), to obtain explants of quality analyzed whose evaluation was about plant development (explants percentual: weight, size, viability, morphology). To visit pharmacy-school to learn how to prepare matrix extracts and High Ultra-Diluted Solutions (HUD) of Calendula off 6DH. Results and Discussion: The stages of teaching semiology and practice in pharmacobotany, besides cultive plant have been completed. Viability was impaired because of lack of irrigation during 4 months (50%). Weight, size were minor than usual but with no statistical significance (p>0.05). Morphology was maintained. Unfortunately, the visit to pharmacy-school couldn’t be performed at this period. Conclusion: Through hybrid learning and face-to-face activities completely realized, students had qualitative perception of the relevance about morphology and quality of plant development, chemistry plant production, aiming for resolutive actions based upon pathophysiology of chronic diseases. Because of pandemic, it was described just a preliminary experience. After returning to normal activities the experiment will be repeated.

Physical-chemical evaluation of mechanically ultra-diluted and dynamized aqueous solutions of Euphorbia tirucalli L. (aveloz): a preliminary study

Physical-chemical evaluation of mechanically ultra-diluted and dynamized aqueous solutions of Euphorbia tirucalli L. (aveloz): a preliminary study

Chronic toxicological effects of ultradiluted solutions of Aveloz (Euphorbia tirucalli Lineu) on healthy mice: a preliminary study

The latex extracted from Euphorbia tirucalli, a plant popularly known as Aveloz, is used in complementary medicine to induce tumor regression. However, as this latex has toxic effects when administered orally in ponderal doses, the present study was designed to assess the effects of high dilutions in healthy mice over a period of 18 weeks. The Aveloz latex-high diluted solutions (latex-HD) were obtained through the interaction of two processes: 1:100 dilution in mass and succussion, using ethanol 70% as a solvent, in the homeopathic dilutions of 5, 15 and 30cH, following Farmacopéia Homeopática Brasileira. Control solutions without latex were compounded (ethanolic-HD) in the same dilutions and were administered simultaneously. The animals which received latex-HD 30cH showed a significant increase in food consumption (p < 0.05) without significant difference in weight gain. In regards to water consumption, no statistical difference was shown when different Aveloz latex-HD groups were compared, apart from the group that received 1 drop of pure latex in water, which presented a significant increase (p < 0.05) in this parameter. Keywords: Euphorbia tirucalli; Aveloz; Toxicology; High Dilutions; Mice.  Efeitos toxicológicos crônicos de altas diluições de Aveloz (Euphorbia tirucalli L.) em camundongos sadios: estudo preliminar. Resumo O látex extraído de Euphorbia tirucalli, planta conhecida popularmente como Aveloz, é utilizado em medicina complementar para induzir regressão tumoral. No entanto, como este látex tem efeitos tóxicos quando administrado por via oral em doses ponderais, este estudo foi desenhado para avaliar os efeitos de altas diluições do mesmo em camundongos sadios por um período de 18 semanas. As altas diluições do látex do Aveloz (látex-HD) foram obtidas através da interação de dois processos: diluição 1:100 em massa e sucussão, utilizando etanol 70% como solvente, nas diluições homeopáticas 5, 15 e 30cH, de acordo com a Famracopéia Homeopática Brasileira. Soluções de controle sem o látex (etanol-HD) foram compostas nas mesmas diluições e ministradas simultaneamente. Os animais que receberam látex-HD 30cH mostraram aumento significativo no consumo de alimento (p < 0,05) sem diferença significativa em ganho de peso. A respeito do consumo de água, não foram observadas diferenças significativas entre os diferentes grupos látex-HD, enquanto que o grupo que recebeu 1 gota de látex puro em água apresentou aumento significativo neste parâmetro (p < 0,05). Palavras-chave: Euphorbia tirucalli; Aveloz; Toxicologia; Altas diluições; Camundongos.  Efectos toxicológicos crónicos de altas diluciones de Euphorbia tirucalli en ratones sanos: estudio preliminar. Resumen El látex extraído de Euphorbia tirucalli, planta conocida popularmente como arbusto de goma, es utilizado en medicina complementaria para la inducción de regresiones tumorales. Como este látex produce efectos tóxicos cuando es administrado por vía oral en dosis ponderales, este estudio fue diseñado para evaluar los efectos de altas diluciones de éste en ratones sanos, durante 18 semanas. Las altas diluciones del látex de E. tirucalli (látex-HD) fueron preparadas mediante la interacción de dos procesos: dilución 1:100 en masa y sucusión, utilizando etanol 70% como solvente en las diluciones homeopáticas 5, 15 y 30cH, según la Farmacopea Homeopática Brasileña. Soluciones de control, sin látex (etanol-HD) fueron compuestas en estas mismas diluciones y administradas simultáneamente. Los animales que recibieron látex-HD 30cH mostraron un aumento significativo del consumo de alimento (p < 0,05), sin diferencias significativas de aumento de peso. Respecto al consumo de agua, no fueron observadas diferencias significativas en los varios grupos látex-HD, mientras que el grupo de recibió 1 gota de látex puro en agua presentó aumento significativo en este parámetro (p < 0,05). Palabras-clave: Euphorbia tirucalli; Aveloz; Toxicologií; Altas diluciones; Ratones.  Correspondence author: Carla Holandino Quaresma, cholandino@yahoo.com How to cite this article: Varricchio MCBN, Pereira C, Sales F, Gomes T, Daudt E, Aquino CL, Barbosa GM, Gomes N, Pyrrho AS, Hobaica PEM, Branco MC, Kuster R, Holandino C. Chronic toxicological effects of high diluted solutions of Aveloz (Euphorbia tirucalli L.) on healthy mice: a preliminary study. Int J High Dilution Res [online]. 2008 [cited YYYY Mmm DD]; 7(25): 174-178. Available from: http://journal.giri-society.org/index.php/ijhdr/article/view/308/371. ÂÂÂ

Continuous Pathway between the Elasto-Inertial and Elastic Turbulent States in Viscoelastic Channel Flow.

Viscoelastic plane Poiseuille flow is shown to become linearly unstable in the absence of inertia, in the limit of high elasticities, for ultradilute polymer solutions. While inertialess elastic instabilities have been predicted for curvilinear shear flows, this is the first ever report of a purely elastic linear instability in a rectilinear shear flow. The novel instability continues up to a Reynolds number (Re) of O(1000), corresponding to the recently identified elasto-inertial turbulent state believed to underlie the maximum-drag-reduced regime. Thus, for highly elastic ultradilute polymer solutions, a single linearly unstable modal branch may underlie transition to elastic turbulence at zero Re and to elasto-inertial turbulence at moderate Re, implying the existence of continuous pathways connecting the turbulent states to each other and to the laminar base state.

Relationship between Flow Properties and Elastic Stresses of Dilute and Ultra-Dilute Polymer Solutions Passing through Small Apertures

Relationship between Flow Properties and Elastic Stresses of Dilute and Ultra-Dilute Polymer Solutions Passing through Small Apertures

Toward the Limitation of Dealloying: Full Spectrum Responsive Ultralow Density Nanoporous Gold for Plasmonic Photocatalytic SERS.

Plasmon-mediated chemical reaction has a great potential to create self-cleaning surface-enhanced Raman scattering (SERS) substrates. However, few works have been reported to promote this goal. Here, we report ultralow density nanoporous gold (ULDNPG) that possesses an impressive full spectrum responsive characteristic with a reflectivity lower than 5% in the waveband of 300-900 nm. ULDNPG was fabricated by a sandwich dealloying strategy from ultradilute Au-Ag solid solutions with the Au content as low as 1-5 at.%. The prepared ULDNPG presents excellent SERS properties, including high sensitivity, high uniformity, and reproducibility. The full spectrum responsive characteristic of ULDNPG leads to an obvious plasmonic photocatalytic activity. The short lifetime of the SP-excited hot carriers causes a restricted self-cleaning SERS property and a strong photothermal effect for ULDNPG structures.

Effect of ultra-diluted nux vomica and cyclophosphamide solutions on the genotoxicity of allopathic cyclophosphamid

Homeopathic medicines comprise the use of pharmacotechnical processes that promote successive dilutions, followed by grinding or agitation of compounds. The purpose of this study was to assess the genotoxic potential of ultra-diluted cyclophosphamide (CF) and nux vomica associated with or without allopathic CF in Swiss Webster mice, using the micronucleus test. The compounds were prepared according to the Brazilian homeopathic pharmacopoeia. Swiss Webster mice were randomly divided into eight groups (n=6) according to the compounds to be tested and received by gavage (vehicle or CF) or by oral mucosa contact (ultra-diluted CF and nux vomica, and dynamized solutions) once a day for 7 days. After this, one of the groups treated with the dynamized compound was challenged by the administration of the allopathic CF. The dynamized ultra-diluted nux vomica and CF compounds showed lower white cell counts in mice. However, no compound was able to mitigate the genotoxic effects of CF in micronucleus assay. The dynamized compounds did not cause damage to the spleen and thymus, and when used intraperitoneally, they were able to mitigate the effect of CF on thymic cortical reduction in mice. Further studies with nux vomica and dynamized CF should be performed to better delineate their possible therapeutic potential in reducing adverse effects on chemotherapy.

Characteristics of polymer semiconductor film prepared by evaporative spray deposition using ultra-dilute solution (ESDUS): application to polymer photovoltaic cells

Organic photovoltaics (OPV) with junction controlled structure are prepared by the evaporative spray deposition using ultra-diluted solution (ESDUS) method with different donor polymer(p) and acceptor fullerene(n) ratio solution. In order to demonstrate the ideal junction, we fabricate the polymer solar cells with single junction(p/n), pin-layered junction (pin) or bulk-heterojunction (BHJ) active layer. The photovoltaic performance is dramatically varied with its junction. And the pin junction has best performance under the sunlight due to its good carrier generation and transport. And also we investigated the temperature dependence of the active layer morphologies at each substrate temperature 60 − 160 °C during its spray-depositing. The domain of active layer became smaller with increasing substrate temperature. The pin-layered cell sprayed at 120 °C gives best photovoltaic performance. Thus, ESDUS enables us to control the junction and morphologies of active layer.

Synthesis of Polymer Single-Chain Nanoparticle with High Compactness in Cosolvent Condition: A Computer Simulation Study.

Polymeric single-chain nanoparticles (SCNPs) are soft nano-objects synthesized by intramolecular crosslinking of isolated single polymer chains. Syntheses of such SCNPs usually need to be performed in a dilute solution. In such a condition, the bonding probability of the two active crosslinking units at a short contour distance along the chain backbone is much higher than those which are far away from each other. Such a reaction condition often results in local spheroidization and, therefore, the formation of loosely packed structures. How to inhibit the local spheroidization and improve the compactness of SCNPs is thus a major challenge for the syntheses of SCNPs. In this study, computer simulations are performed and the fact that a precollapse of the polymer chain conformation in a cosolvent condition can largely improve the probability of the crosslinking reactions at large contour distances is demonstrated, favoring the formations of closely packed globular structures. As a result, the formed SCNPs can be more spherical and have higher compactness than those fabricated in ultradilute good solvent solution in a conventional way. It is believed this simulation work can provide a insight into the effective syntheses of SCNPs with spherical conformations and high compactness.

Plasmonic color generation and refractive index sensing with three-dimensional air-gap nanocavities.

Three-dimensional (3D) air-gap metal-coated nanocavities with tunable geometries, changeable heights, and improved smoothness are fabricated by combining electron beam lithography (EBL), ultra dilute hydrofluoric acid solution wet etching (UDHFE), and metal magnetron sputtering technologies. With different shapes, heights, and separations of the nanocavities, the strong electromagnetic resonances inside the nanocavities are changed in different extent, resulting in broad gamut and sophisticated plasmonic color generation. The nanocavities-based metasurface is also used to construct a real-time and label-free refractive index sensor with 372 nm/RIU sensitivity, which shows distinct colorimetric change between different mediums. This nanocavities may find extensive potential applications in high-fidelity color printing, high-density information storage, and on-chip colorimetric label-free biomedical sensing.

Ultra-diluted Solutions of Nux vomica in the Remediation of Metals in Soils and Bioavailability for Soybeans

The aim of this study was to evaluate the homeopathic medicine Nux vomica in the remediation of soils contaminated with cadmium (Cd) and lead (Pb) and the bioavailability of these metals in soybean plants. To this end the soil was contaminated prior to sowing, using CdCl2H2O and PbCl2 salts in three rates, based on the resolution of the research values of resolution No. 420 of CONAMA, resulting in 0.0, 3.0 and 9.0 mg kg-1 for Cd and 89.0, 180.0 and 540.0 mg kg-1 for Pb. The homeopathic remedy Nux vomica was used in dynamizations 12, 24, 48, 96, 200 and 400 CH (Centesimal Hanhemannian), being the witness with distilled water. Medicines were applied to the soil seven days before sowing and after sowing, every 14 days applied in the plant until complete the cycle. During cultivation were evaluated development, gas exchange, nutrient composition, component production and bioavailability of metals in the plant. The results demonstrate that Nux vomica medicine interfered in height and stem diameter and CO2 assimilation, stomatal conductance and transpiration of soybean plants, but did not affect the bioavailability of metals to plants.

Measurement of flow properties and mean elastic stresses of dilute polymer solutions passing through small slits

We measured pressure drops and jet thrusts of dilute (100 ppm and 10 ppm) or ultra-dilute (1 ppm) aqueous solutions of polymer in flows through slits with width of 1.0 mm, 480 μm, and 122 μm owing to investigation of flow properties of dilute polymer solution passing through a small slit. Good agreement between the experimental results of water alone and the predictions was obtained within the experimental errors. However, the dilute and ultra-dilute polymer solutions exhibited lower values. To understanding the experimental results, we estimated mean elastic stresses via jet thrust method. Moreover, we clarified that power-law relationship between mean elastic stress and mean velocity, and it corresponded to the flow properties via the pressure drops.

Extracting structural information of Au colloids at ultra-dilute concentrations: identification of growth during nanoparticle immobilization.

Sol-immobilization is increasingly used to achieve supported metal nanoparticles (NPs) with controllable size and shape; it affords a high degree of control of the metal particle size and yields a narrow particle size distribution. Using state-of-the-art beamlines, we demonstrate how X-ray absorption fine structure (XAFS) techniques are now able to provide accurate structural information on nano-sized colloidal Au solutions at μM concentrations. This study demonstrates: (i) the size of Au colloids can be accurately tuned by adjusting the temperature of reduction, (ii) Au concentration, from 50 μM to 1000 μM, has little influence on the average size of colloidal Au NPs in solution and (iii) the immobilization step is responsible for significant growth in Au particle size, which is further exacerbated at increased Au concentrations. The work presented demonstrates that an increased understanding of the primary steps in sol-immobilization allows improved optimization of materials for catalytic applications.