DOCSLIB.ORG

Oral Supplementation of Orthosilicic Acid and Its Impact on Hair Quality

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Oral Supplementation of Orthosilicic Acid and Its Impact on Hair Quality www.medigraphic.org.mx Medicina Cutánea Ibero-Latino-Americana Localizador 16041 Oral supplementation of orthosilicic acid and its impact on hair quality Suplemento oral de ácido ortosilícico y su impacto en la calidad del cabello Luciana Nakanishi,* Bruna Bombonatti,* Letícia Sabo Muller,‡ Ricardo Tadeu Villa,§ Maria Valéria Robles Velasco,|| Valcinir Bedin,¶ Ana Carolina Fortes Braga Brederodes Villa§ Key words: Orthosilicic acid, ABSTRACT RESUMEN hair growth, resistance. Objectives: We evaluated the correlation between metric Objetivos: Evaluar la correlación entre los parámetros métricos parameters and laboratory assessments of hair taken from y las valoraciones de laboratorio, de pelo extraído de pacientes Palabras clave: patients undergoing oral supplementation of orthosilicic acid. sometidos a suplementación oral de ácido ortosilícico. Material Ácido ortosilícico, Material and methods: 34 women aged between 17 and y métodos: 34 mujeres de entre 17 y 57 años recibieron una crecimiento del cabello, 57 years received an oral dose of 30 mg of orthosilicic acid dosis oral de 30 mg de ácido ortosilícico durante cinco meses. resistencia. for five months. Hair samples (pre and post-treatment) were Se obtuvieron muestras de pelo (pre- y postratamiento) de un obtained from an area of 1 cm² on the occipital protuberance área de 1 cm² sobre la protuberancia occipital y se sometieron and submitted to ultrasound bath in a distilled water solution. a un baño de ultrasonido en una solución de agua destilada. After that, we tested this water using spectrophotometric Después de eso, analizamos el agua mediante la técnica espec- technique for measuring the hair ability to preserve proteins trofotométrica para medir la capacidad del cabello para preservar during physical stress. Hair growth was also assessed every las proteínas durante el estrés físico. El crecimiento del cabello month, before treatment and during treatment. We applied a también se evaluó cada mes, antes y durante el tratamiento. Se questionnaire addressing the perception of patients about their aplicó un cuestionario dirigido a la percepción de los pacientes hair. Results: 83% of patients believed that there was overall sobre su cabello. Resultados: 83% de los pacientes conside- improvement of hair quality after treatment. 79.41% of patients raron que hubo una mejoría general de la calidad del cabello exhibited increasing in hair growth rate and this increase was después del tratamiento. El 79.41% de los pacientes mostró of 37.6%. Protein loss analysis showed a improvement in hair un aumento en la tasa de crecimiento capilar y este aumento quality. Conclusion: We suggest that orthosilicic acid has a fue del 37.6%. El análisis de pérdida de proteínas mostró una beneficial role in the hair, leading to a faster growth rate and mejora en la calidad del cabello. Conclusión: Se sugiere que el * Dermatologist. an increase in resistance to aggression. ácido ortosilícico tiene un papel beneficioso en el cabello, que ‡ MD. conduce a una tasa de crecimiento más rápido y a un aumento § Professor UFMA. de la resistencia a la agresión. || Professor USP. ¶ PhD UNICAMP. Abbreviations: Si = Silicon. INTRODUCTION intake of oligoelements and vitamins and OSA = Orthosilicic acid. 5 ppm = part(s) per million. environmental aggression. These deleterious air is unquestionably one of the most effects are manifested in the form of difficult Confl icto de intereses: Ninguno. Himportant personal attributes in all combing, brittleness and dryness. cultures, and, therefore, its characteristics are In its turn, silicon (Si) is a well known and of great psychological importance, justifying ubiquitous component present in several Received: 6 19/September/2016. all the studies focusing on how to conserve tissues of human body and is found at 1-10 Accepted: and promote hair quality. In this particular, is ppm in hair7 and nails.8 Additionally, silicon 02/March/2017. fundamentalwww.medigraphic.org.mx to consider that human hair has an accumulates in the stratum corneum of outer protective layer, which surrounds the cells epidermis and in hair cuticle.9 Recently, it was of the highly keratinized cortex and a structural confirmed that the phanars, hair and nails are hierarchy of disulfide bonds that has influence more rich in silicon10 than the remaining parts on the mechanical properties of hair.1-4 of the skin and this element accumulates more Changes in growth and hair quality can intensely in the outer layer of the epidermis be induced by protein malnutrition or low and in the cuticule of hair (Table 1), wich Med Cutan Iber Lat Am 2017; 45 (1): 29-35 www.medigraphic.com/medicinacutanea Nakanishi L et al. Oral supplementation of orthosilicic acid and its impact on hair quality ORIGINAL explains the usage of silicon in the treatment of alopecia The silicon absorption is considerably higher in the form since the middle of last century. Further, from his results,11 of silanol as shown by a silicon study and osteogenesis.15 Fregert raised the question that silicon levels strongly Furthermore, toxicological studies referred to the soluble contributes to the solidity and the high resistance of silicon derivative as safe, with no genotoxic for use in keratinous tissues and plays a role as a barrier. Indeed, it living beings.16,17 has been shown that silicon can improve the skin barrier of normal skin and prevents premature skin aging and Objective of the study psoriasis progression.12 In animals, deficit of bioavailable silicon can be Our primary objective of this study was to evaluate the bound to severe diseases (arteriosclerosis, osteoarthritis, correlation between metric parameters and laboratory hypertension and aging processes).8,13 Beyond that, silicon assessments of patients undergoing oral supplementation deficiency in human body has been connected to many of silicon. degenerative diseases (e.g., Alzheimer’s) and tissue aging Our secondary objective was to describe the subjective processes, and that the normal silicon blood plasma results of the hair quality after oral supplementation of concentration varies from 5 to 20 micromoles,14 we silicon. propose that silicon supplementation could be considered. MATERIAL AND METHODS Table 1. Silicon content of the skin, hair and nails in man We conducted an uncontrolled longitudinal study in wich (μg silicon/g of dry tissue). our intervention was the supplementation of silicon for Abdominal epidermis 106 Entire skin 23 women/18 men five months. Dermsi with light 19 Nails 56 All of our 34 patients were women aged between 17 covering of hair and 57 years, as displayed in figure 1. Dermis with strong 25 Hair 90 At day zero, we shaved the hair of an area equivalent covering of hair Plantar dermis 13 to 1 cm² on the occipital protuberance of each patient. After this procedure, we measured three times at each 34 31 28 25 22 19 16 Patients 13 10 7 www.medigraphic.org.mx 4 1 0 10 20 30 40 50 60 Years Figure 1. Patients age. Med Cutan Iber Lat Am 2017; 45 (1): 29-35 30 www.medigraphic.com/medicinacutanea Nakanishi L et al. Oral supplementation of orthosilicic acid and its impact on hair quality ORIGINAL moment (in order to validate the data) the hair length at growth after treatment has increased (we rejected H0 = intervals of 30 days for 3 months and obtained medium H1 and accepted H0 ≠ H1). growth rate for each participant before the treatment was In the same way, our absorbance data of hair samples started. After these first three months, every patient was exhibited significative improvement in hair resistance after submitted to a new trichotomy and we re-started monthly treatment, with a p < 0.00283598, we assumed that hair measures, but, from this moment on, they were receiving resistance after treatment has increased (we rejected H0 the dose of 30 mg of orthosilicic acid in the form of OSA = H1 and accepted H0 ≠ H1). (orthosilicic acid) stabilized in marine collagen at a dose of 600 mg over five months. This dosage was divided in RESULTS two capsules of 300 mg taken twice a day, at least two hours after meals for better absorption of orthosilicic acid. Our subjective data are as follows (Table 2): Patients participating in the study answered a subjective As we can see, features related to hair texture received questionnaire about their hair focusing the following the highest score, and, in total, 83% of the volunteers parameters: smoothness, shine, growth, and fall. They reported a general improvement in the hair quality during were instructed not to change the diet, daily activities treatment. Although growth was not the highest score, it and medications. Women who used any medication that was a feature with a very good response to treatment, as could alter the variables addressed in the study, such as we can see below in our objective data (Table 2). vitamins and other supplements were excluded. If they In (Figure 2), we display the average rate of hair growth were using contraceptives, they had to continue and, if (cm/month). In blue, before treatment and, in red, during they didn’t, they couldn’t start until the end of the research. treatment. This chart exposes precisely our results: They attributed the following score, taking into account the grade of improvement of each parameter: significant • In 79.4% of subjects (27/34), hair growth has improvement (2), moderate improvement (1) and no increased (as mentioned above, with significance improvement (0). Medium scores were calculated and as described in statistical analysis). are displayed in the next section. • Comparing medium growth rate before and during When exposition to physical or chemical treatments treatment, there was an increase of 37.6%. occurs, hair strand may exhibit damage in its structure, and therefore, a change occurs in the protein composition Protein loss and resistance.18,19 In order to evaluate hair resistance, we used a validated assay that consists in submitted When we compared protein loss of samples obtained hair sample to a physical aggression (ultrasonic wave) before and after treatment, we revealed that hair was in a tube with water and assess how much protein that more resistant after treatment and lost 84.2% less protein hair sample looses to the water.
Load more

Recommended publications
  • Sodium Silicate Crops
    Sodium Silicate Crops 1 Identification of Petitioned Substance 2 3 Chemical Names: CAS Numbers: 4 Sodium Silicate 1344-09-8 5 6 Other Name: Other Codes: 7 Sodium metasilicate; Sodium silicate glass; EPA PC code: 072603 (NLM, 2011a); European 8 Sodium water glass; Silicic acid, sodium salt; Inventory of Existing Commercial Chemical 9 tetrasodium orthosilicate (IPCS, 2004) Substances (EINECS) Number: 215-687-4 (IPCS, 10 2004) 11 Trade Names: 12 Waterglass, Britesil, Sikalon, Silican, Carsil, 13 Dryseq, Sodium siloconate, Star, Soluble glass, 14 Sodium polysilicate (NLM, 2011a), N® - PQ 15 Corporation (OMRI, 2011) 16 Characterization of Petitioned Substance 17 18 Composition of the Substance: 19 The basic formula of sodium silicate is Na2O· nO2Si, which represents the components of silicon dioxide (SiO2) 20 and sodium oxide (Na2O) and the varying ratios of the two in the various formulations. This ratio is commonly 21 called the molar ratio (MR), which can range from 0.5 to 4.0 for sodium silicates and varies depending on the 22 composition of the specific sodium silicate. The structural formulas of these silicates are also variable and can be 23 complex, depending on the formulation, but generally do not have distinct molecular structures (IPCS, 2004). 24 The basic structure of soluble silicates, including sodium and potassium silicates, is a trigonal planar 25 arrangement of oxygen atoms around a central silicon atom, as depicted in Figure 1 below. Physical and 26 chemical properties of sodium silicate are summarized in Table 1, on page 2. 27 28 29 30 31 32 33 34 35 Figure 1: Chemical Structure of Sodium Silicate (NLM, 2011a) 36 37 Specific Uses of the Substance: 38 39 Sodium silicate and other soluble silicates have been used in many industries since the early 19th century.
    [Show full text]
  • Guidance for Identification and Naming of Substance Under REACH
    Guidance for identification and naming of substances under 3 REACH and CLP Version 2.1 - May 2017 GUIDANCE Guidance for identification and naming of substances under REACH and CLP May 2017 Version 2.1 2 Guidance for identification and naming of substances under REACH and CLP Version 2.1 - May 2017 LEGAL NOTICE This document aims to assist users in complying with their obligations under the REACH and CLP regulations. However, users are reminded that the text of the REACH and CLP Regulations is the only authentic legal reference and that the information in this document does not constitute legal advice. Usage of the information remains under the sole responsibility of the user. The European Chemicals Agency does not accept any liability with regard to the use that may be made of the information contained in this document. Guidance for identification and naming of substances under REACH and CLP Reference: ECHA-16-B-37.1-EN Cat. Number: ED-07-18-147-EN-N ISBN: 978-92-9495-711-5 DOI: 10.2823/538683 Publ.date: May 2017 Language: EN © European Chemicals Agency, 2017 If you have any comments in relation to this document please send them (indicating the document reference, issue date, chapter and/or page of the document to which your comment refers) using the Guidance feedback form. The feedback form can be accessed via the EVHA Guidance website or directly via the following link: https://comments.echa.europa.eu/comments_cms/FeedbackGuidance.aspx European Chemicals Agency Mailing address: P.O. Box 400, FI-00121 Helsinki, Finland Visiting address: Annankatu 18, Helsinki, Finland Guidance for identification and naming of substances under 3 REACH and CLP Version 2.1 - May 2017 PREFACE This document describes how to name and identify a substance under REACH and CLP.
    [Show full text]
  • Study of the System Cao-Sio2-H2O at 30 C and of the Reaction of Water On
    U.S. Department of Commerce Bureau of Standards RESEARCH PAPER RP687 Part of Bureau of Standards Journal of Research, vol. 12, June 1934 STUDY OF THE SYSTEM CaO-Si02-H2 AT 30 C AND OF THE REACTION OF WATER ON THE ANHYDROUS CALCIUM SILICATES By E. P. Flint and Lansing S. Wells abstract A graph has been prepared representing the solubility of silica at 30 C in solu- tions containing increasing concentrations of lime up to saturation, the solutions being in "equilibrium" with solid phases composed of hydrated combinations of lime and silica. An electrometric and analytical study of both supersaturated and unsaturated solutions of silica at definite concentrations of lime, when corre- lated with these equilibrium solubility relationships, indicates the existence of definite compounds in the system CaO-Si0 2-H 2 which may be the hydrated calcium salts of orthosilicic acid. Experimental values were obtained for the hydrolysis constants of these salts from which ionization constants for the four steps in the dissociation of orthosilicic acid were calculated. A study of the reaction of water upon the anhydrous calcium silicates (CaO Si02 , 3CaO- 2Si0 2 , 7-2CaO-Si0 ,3-2CaO Si0 , ) showed that the products formed depend 2 , 2 3CaOSi0 2 upon the equilibrium relationships of the system CaO-Si02-H 2 0. Of these compounds all but monocalcium silicate (CaO-Si02 ) form solutions which pre- cipitate hydrated calcium silicate on standing. Application of the same methods to a study of the reaction of water upon a portland cement indicated that hydrated calcium orthosilicate is formed during the hydration of portland cement.
    [Show full text]
  • United States Patent (19) 11 4,169,930 Blount 45) Oct
    United States Patent (19) 11 4,169,930 Blount 45) Oct. 2, 1979 (54) PROCESS FOR THE PRODUCTION OF 58 Field of Search ................. 260/448.2 N, 448.2 E; AMNO SILICATE COMPOUNDS AND 528/38 THER CONDENSATION PRODUCTS 76 Inventor: David H. Blount, 5450 Lea St., San 56) References Cited Diego, Calif. 92105 U.S. PATENT DOCUMENTS 21 Appl. No.: 786,617 4,011,253 3/1977 Blount ........................... 260/448.2 E 4,089,883 5/1978 Blount ....................... 260/448.2 E X (22) Filed: Apr. 8, 1977 Primary Examiner-Paul F. Shaver Related U.S. Application Data 57 ABSTRACT 60) Division of Ser. No. 652,338, Jan. 26, 1976, Pat. No. 4,033,935, which is a continuation-in-part of Ser. No. Silicic-amino compounds are formed by the chemical 559,313, Mar. 17, 1975, Pat. No. 3,979,362, which is a reaction of silicic acid with amino compounds in the continuation-in-part of Ser. No. 71,628, Sep. 11, 1970, presence of a suitable alkali at a suitably elevated tem abandoned. perature, and then by reacting the resultant compounds 51 Int. Cl’.............................................. C08G 77/04 with an aldehyde, a condensation product is formed. (52) U.S. C. .............................. 528/38; 260/448.2 N; 260/448.2 E 4 Claims, No Drawings 4,169,930 1. 2 PROCESS FOR THE PRODUCTION OF AMINO Reactions with other amino compounds are expected SILICATE COMPOUNDS AND THER to be similar to these, so that the mol ratios of the reac CONDENSATION PRODUCTS tants should be selected accordingly. Amino silicate compounds are theorized to react with CROSS-REFERENCE TO RELATED an aldehyde to form condensation products as follows: APPLICATIONS Urea silicate is theorized to react with formaldehyde This application is a division of U.S.
    [Show full text]
  • A Bound Form of Silicon in Glycosaminoglycans And
    Proc. Nat. Acad. Sci. USA Vol. 70, No. 5, pp. 1608-1612, May 1973 A Bound Form of Silicon in Glycosaminoglycans and Polyuronides (polysaccharide matrix/connective tissue) KLAUS SCHWARZ Laboratory of Experimental Metabolic Diseases, Veterans Administration Hospital, Long Beach, California 90801; and Department of Biological Chemistry, School of Medicine, University of California at Los Angeles, Calif. 90024 Communicated by P. D. Boyer, March 19, 1973 ABSTRACT Silicon was found to be a constituent of notably hyaluronic acid, chondroitin 4-sulfate, dermatan certain glycosaminoglycans and polyuronides, where it sulfate, and heparan sulfate, contain relatively large amounts occurs firmly bound to the polysaccharide matrix. 330-554 ppm of bound Si were detected in purified hyaluronic acid of the element, not as free silicate ions or silicic acid but as a from umbilical cord, chondroitin 4-sulfate, dermatan firmly bound component of the polysaccharide matrix. High sulfate, and heparan sulfate. These amounts correspond to amounts of bound Si were also detected in two polyuronides, 1 atom of Si per 50,000-85,000 molecular weight or 130-280 pectin and alginic acid. Stability tests and enzymatic studies repeating units. 57-191 ppm occur in chondroitin 6-sulfate, evidence for the assumption that the Si is linked heparin, and keratan sulfate-2 from cartilage, while provide hyaluronic acids from vitreous humor and keratan sulfate- covalently to the polysaccharides in question, possibly as an 1 from cornea were Si-free. Large amounts of bound Si are ether (or ester-like) derivative of silicic acid, i.e., a silanolate. also present in pectin (2580 ppm) and alginic acid (451 ppm).
    [Show full text]
  • Water at Molecular Interfaces: Structure and Dynamics Near Biomolecules and Amorphous Silica
    WATER AT MOLECULAR INTERFACES: STRUCTURE AND DYNAMICS NEAR BIOMOLECULES AND AMORPHOUS SILICA DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Ali A. Hassanali, M.S. Biophysics Graduate Program The Ohio State University 2010 Dissertation Committee: Professor Sherwin J. Singer, Adviser Professor Dongping Zhong Professor Terrence Conlisk Professor Justin Wu ABSTRACT Water, the fundamental constituent of life, has been found to have a critical role at both organic and inorganic surfaces. The properties of water near surfaces, is known to be different from water far away from the interface. This dissertation explores the degree to which inorganic materials such as amorphous silica (glass) and biomolecular surfaces change the properties of water. Of particular interest is the interplay between biological molecules - proteins and nucleic acids - and their aqueous environment, and how this determines biological function. The mobility of water near protein surfaces has been of considerable recent in- terest. There have been many reports in the literature postulating that interfacial water is incapable of undergoing rapid rotational motions due to strong electrostatic forces from the protein surface. This has led to confusing and conflicting interpre- tations on the molecular origin of the slow features observed in certain experiments that probe protein surfaces. Our theoretical studies resolve the conflicts and show that the slow dynamics observed, originates from the protein and water jostling in a concerted fashion. Our studies support a change in the paradigm for the function of proteins to include both the protein and the surrounding water as active participants in biological function.
    [Show full text]
  • Silicon Cycling in Soils Revisited
    plants Review Silicon Cycling in Soils Revisited Jörg Schaller 1,* , Daniel Puppe 1, Danuta Kaczorek 1,2 , Ruth Ellerbrock 1 and Michael Sommer 1,3 1 Leibniz Centre for Agricultural Landscape Research (ZALF), 15374 Müncheberg, Germany; [email protected] (D.P.); [email protected] (D.K.); [email protected] (R.E.); [email protected] (M.S.) 2 Department of Soil Environment Sciences, Warsaw University of Life Sciences (SGGW), 02-776 Warsaw, Poland 3 Institute of Environmental Science and Geography, University of Potsdam, 14476 Potsdam, Germany * Correspondence: [email protected]; Tel.: +49-33432-82371 Abstract: Silicon (Si) speciation and availability in soils is highly important for ecosystem functioning, because Si is a beneficial element for plant growth. Si chemistry is highly complex compared to other elements in soils, because Si reaction rates are relatively slow and dependent on Si species. Consequently, we review the occurrence of different Si species in soil solution and their changes by polymerization, depolymerization, and condensation in relation to important soil processes. We show that an argumentation based on thermodynamic endmembers of Si dependent processes, as currently done, is often difficult, because some reactions such as mineral crystallization require months to years (sometimes even centuries or millennia). Furthermore, we give an overview of Si reactions in soil solution and the predominance of certain solid compounds, which is a neglected but important parameter controlling the availability, reactivity, and function of Si in soils. We further discuss the drivers of soil Si cycling and how humans interfere with these processes. The soil Si cycle is of major importance for ecosystem functioning; therefore, a deeper understanding of drivers of Si cycling (e.g., predominant speciation), human disturbances and the implication for important soil properties (water storage, nutrient availability, and micro aggregate stability) is of fundamental relevance.
    [Show full text]
  • Synthesis and Characterization of Silicate Ester Prodrugs and Poly(Ethylene Glycol)
    Synthesis and Characterization of Silicate Ester Prodrugs and Poly(ethylene glycol)-b-poly(lactic-co-glycolic acid) Block Copolymers for Formulation into Prodrug-Loaded Nanoparticles A DISSERTATION SUBMITTED TO THE FACULTY OF THE GRADUATE SCHOOL OF THE UNIVERSITY OF MINNESOTA BY Adam Richard Wohl IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Doctor of Philosophy Thomas R. Hoye, Advisor September 2012 © Adam Richard Wohl September 2012 Acknowledgements I have been blessed to have the support of my family, friends, and colleagues. Without your help and encouragement, my graduate career would not have been possible. First of all, I would like to thank my advisor Prof. Tom Hoye. Over the past five years, he has been a consistent and patient mentor that leads first and foremost by setting a world-class example. He has taught me so much about analyzing problems, having fun while working hard, and always paying attention to the details. He has constantly taught me during our experimental discussions, results analysis, and late night (or, as I believe Tom would say, “mid-evening”) grant/manuscript writing sessions. I have learned not only many, many chemical concepts and scientific strategies, but also other valuable skills – how to clearly present ideas and make a compelling presentation to the right audience. Thank you, Tom, for all of the time that you have invested in both my scientific career and life – you have my utmost appreciation and respect. I would also like to thank Prof. Chris Macosko for all of his time, help, and expertise that he has provided to this collaborative project.
    [Show full text]
  • Unveiling the Role of Rhizaria in the Silicon Cycle Natalia Llopis Monferrer
    Unveiling the role of Rhizaria in the silicon cycle Natalia Llopis Monferrer To cite this version: Natalia Llopis Monferrer. Unveiling the role of Rhizaria in the silicon cycle. Other. Université de Bretagne occidentale - Brest, 2020. English. NNT : 2020BRES0041. tel-03259625 HAL Id: tel-03259625 https://tel.archives-ouvertes.fr/tel-03259625 Submitted on 14 Jun 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. THESE DE DOCTORAT DE L'UNIVERSITE DE BRETAGNE OCCIDENTALE ECOLE DOCTORALE N° 598 Sciences de la Mer et du littoral Spécialité : Chimie Marine Par Natalia LLOPIS MONFERRER Unveiling the role of Rhizaria in the silicon cycle (Rôle des Rhizaria dans le cycle du silicium) Thèse présentée et soutenue à PLouzané, le 18 septembre 2020 Unité de recherche : Laboratoire de Sciences de l’Environnement Marin Rapporteurs avant soutenance : Diana VARELA Professor, Université de Victoria, Canada Giuseppe CORTESE Senior Scientist, GNS Science, Nouvelle Zélande Composition du Jury : Président : Géraldine SARTHOU Directrice de recherche, CNRS, LEMAR, Brest, France Examinateurs : Diana VARELA Professor, Université de Victoria, Canada Giuseppe CORTESE Senior Scientist, GNS Science, Nouvelle Zélande Colleen DURKIN Research Faculty, Moss Landing Marine Laboratories, Etats Unis Tristan BIARD Maître de Conférences, Université du Littoral Côte d’Opale, France Dir.
    [Show full text]
  • Biological and Therapeutic Effects of Ortho-Silicic Acid
    Jurkić et al. Nutrition & Metabolism 2013, 10:2 http://www.nutritionandmetabolism.com/content/10/1/2 REVIEW Open Access Biological and therapeutic effects of ortho-silicic acid and some ortho-silicic acid-releasing compounds: New perspectives for therapy Lela Munjas Jurkić1, Ivica Cepanec2, Sandra Kraljević Pavelić1* and Krešimir Pavelić1 Abstract Silicon (Si) is the most abundant element present in the Earth's crust besides oxygen. However, the exact biological roles of silicon remain unknown. Moreover, the ortho-silicic acid (H4SiO4), as a major form of bioavailable silicon for both humans and animals, has not been given adequate attention so far. Silicon has already been associated with bone mineralization, collagen synthesis, skin, hair and nails health atherosclerosis, Alzheimer disease, immune system enhancement, and with some other disorders or pharmacological effects. Beside the ortho-silicic acid and its stabilized formulations such as choline chloride-stabilized ortho-silicic acid and sodium or potassium silicates (e.g. M2SiO3; M= Na,K), the most important sources that release ortho-silicic acid as a bioavailable form of silicon are: colloidal silicic acid (hydrated silica gel), silica gel (amorphous silicon dioxide), and zeolites. Although all these compounds are characterized by substantial water insolubility, they release small, but significant, equilibrium concentration of ortho-silicic acid (H4SiO4) in contact with water and physiological fluids. Even though certain pharmacological effects of these compounds might be attributed to specific structural characteristics that result in profound adsorption and absorption properties, they all exhibit similar pharmacological profiles readily comparable to ortho-silicic acid effects. The most unusual ortho-silicic acid-releasing agents are certain types of zeolites, a class of aluminosilicates with well described ion(cation)-exchange properties.
    [Show full text]
  • TM-44-12-05.Pdf
    Registrierung TM-44-12-05 The PSI/Nagra Chemical Thermodynamic Database 12/07 Ersetzt Titel (Update of the Nagra/PSI TDB 01/01): - Data Selection for Silicon Erstellt Autoren/ Autorinnen Wolfgang Hummel 4. June 2014 Summary: Data reported in the literature for dissolved silica and aqueous metal silicate complexes have been reviewed by the author. Literature reviewed in OECD NEA’s books “Chemical Thermodynamics of Uranium” by GRENTHE et al. (1992), “Update on the Chemical Thermodynamics of Uranium, Neptunium, Plutonium, Americium and Technetium” by GUILLAUMONT et al. (2003), “Chemical Thermodynamics of Nickel” by GAMSJÄGER et al. (2005), “Chemical Thermodynamics of Zirconium” by BROWN et al. (2005) and “Chemical Thermodynamics of Thorium” by RAND et al. (2009) have been considered in this review. The updated database is called PSI/Nagra Chemical Thermodynamic Database 12/07. This is the 4th of a continuing series of reports concerning the PSI/Nagra Chemical Thermodynamic Database 12/07. Verteile Abt. Empfänger / Empfängerinnen Expl. Abt. Empfänger / Empfängerinnen Expl Expl. r . 44 B. Baeyens 1 Nagra V. Cloet 1 Bibliothek 2 U. Berner 1 L. Johnson 1 S. Churakov 1 J. Mibus 1 Reserve 4 E. Curti 1 J. Schneider 1 R. Dähn 1 B. Schwyn 1 Total 29 T. Gimmi 1 P. Zuidema 1 M. Glaus 1 Seiten 40 W. Hummel 1 New Bern F.J. Pearson 1 G. Kosakowski 1 Beilagen - D. Kulik 1 M. Marques 1 Informationsliste W. Pfingsten 1 D 1 2 3 4 5 8 9 A T. Thoenen 1 J. Tits 1 Visum Abt./Laborleitung: L. Van Loon 1 E. Wieland 1 TM-44-12-05 / page 2 Silica and silicates 8.1 Elemental silicon Silicon metal and gas are not relevant under environmental conditions.
    [Show full text]
  • Study of Colloidal Silica Formation and Precipitation in Solution of Mutnovskoe Hydrothermal Field (Kamchatka, Russia)
    Proceedings World Geothermal Congress 2005 Antalya, Turkey, 24-29 April 2005 Study of Colloidal Silica Formation and Precipitation in Solution of Mutnovskoe Hydrothermal Field (Kamchatka, Russia) Potapov V.V.1, Povarov K.O.2, Podverbny V.M.3, Guseva O.V.4 1,4Geotechnological Research Center, Far East Branch of Russian Academy of Sciences Petropavlovsk-Kamchatsky, Russia, 683002, Severo-Vostochnoe shosse, 30, p. box 56, E-mail: [email protected] 2,3Open joint stock company “Geoterm”, Mosow, Russia, 111250, Krasnokazarmennaya street, 9/1, E-mail: [email protected] Keywords: nucleation and polymerization of silica acid, power stations pressure and temperature of the solution colloidal silica, coagulation, silica precipitation and decrease, and a part of solution is evaporated. Total content utilization, efficiency of heat carrier of silica Ct in liquid phase after coming solution to the surface can reach in this case 700-1500 mg/kg. Owing to ABSTRACT this water solution becomes oversaturated with respect to the solubility of amorphous silica C . According to the Physical and chemical processes in hydrothermal solution e experimental data (Marshall W.L., 1980), value C (mg/kg) in which colloidal silica took part were researched. The rate e for pure water depends on absolute temperature T by the of nucleation of orthosilicic acid molecules H SiO were 4 4 following way: calculated with the help of mathematical model. The order and constant of rate of silicic acid polymerization reaction log (C /60) = -0.1185 – 1.126⋅103/T + 2.3305⋅105/T2 – were determined. The sizes and diffusion coefficients of e 3.6784⋅107/T3, (2) colloidal silica particles were measured.
    [Show full text]