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Takekiyo T, Yamada N, Nakazawa CT, Amo T, Asano A, Yoshimura Y. Formation of α-synuclein aggregates in aqueous ethylammonium nitrate solutions. Biopolymers 2020; 111:e23352. [PMID: 32203628 DOI: 10.1002/bip.23352] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 02/04/2023]
Abstract
The effect of adding ethylammonium nitrate (EAN), which is an ionic liquid (IL), on the aggregate formation of α-synuclein (α-Syn) in aqueous solution has been investigated. FTIR and Raman spectroscopy were used to investigate changes in the secondary structure of α-Syn and in the states of water molecules and EAN. The results presented here show that the addition of EAN to α-Syn causes the formation of an intermolecular β-sheet structure in the following manner: native disordered state → polyproline II (PPII)-helix → intermolecular β-sheet (α-Syn amyloid-like aggregates: α-SynA). Although cations and anions of EAN play roles in masking the charged side chains and PPII-helix-forming ability involved in the formation of α-SynA, water molecules are not directly related to its formation. We conclude that EAN-induced α-Syn amyloid-like aggregates form at hydrophobic associations in the middle of the molecules after masking the charged side chains at the N- and C-terminals of α-Syn.
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Affiliation(s)
- Takahiro Takekiyo
- Department of Applied Chemistry, National Defense Academy, Yokosuka, Kanagawa, Japan
| | - Natsuki Yamada
- Department of Applied Chemistry, National Defense Academy, Yokosuka, Kanagawa, Japan
| | - Chikako T Nakazawa
- Department of Applied Chemistry, National Defense Academy, Yokosuka, Kanagawa, Japan
| | - Taku Amo
- Department of Applied Chemistry, National Defense Academy, Yokosuka, Kanagawa, Japan
| | - Atsushi Asano
- Department of Applied Chemistry, National Defense Academy, Yokosuka, Kanagawa, Japan
| | - Yukihiro Yoshimura
- Department of Applied Chemistry, National Defense Academy, Yokosuka, Kanagawa, Japan
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Cao X, Lu H, Liu J, Lu W, Guo L, Ma M, Zhang B, Guo Y. 3D plotting in the preparation of newberyite, struvite, and brushite porous scaffolds: using magnesium oxide as a starting material. J Mater Sci Mater Med 2019; 30:88. [PMID: 31325082 DOI: 10.1007/s10856-019-6290-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/08/2019] [Indexed: 06/10/2023]
Abstract
Calcium phosphate (CaP)-containing materials, such as hydroxyapatite and brushite, are well studied bone grafting materials owing to their similar chemical compositions to the mineral phase of natural bone and kidney calculi. In recent studies, magnesium phosphate (MgP)-containing compounds, such as newberyite and struvite, have shown promise as alternatives to CaP. However, the different ways in degradation and release of Mg2+ and Ca2+ ions in vitro may affect the biocompatibility of CaP and MgP-containing compounds. In the present paper, newberyite, struvite, and brushite 3D porous structures were constructed by 3D-plotting combining with a two-step cementation process, using magnesium oxide (MgO) as a starting material. Briefly, 3D porous green bodies fabricated by 3D-plotting were soaked in (NH4)2HPO4 solution to form semi-manufactured 3D porous structures. These structures were then soaked in different phosphate solutions to translate the structures into newberyite, struvite, and brushite porous scaffolds. Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectrometry (EDS) were used to characterize the phases, morphologies, and compositions of the 3D porous scaffolds. The porosity, compressive strength, in vitro degradation and cytotoxicity on MC3T3-E1 osteoblast cells were assessed as well. The results showed that extracts obtained from immersing scaffolds in alpha-modified essential media induced minimal cytotoxicity and the cells could be attached merely onto newberyite and brushite scaffolds. Newberyite and brushite scaffolds produced through our 3D-plotting and two-step cementation process showed the sustained in vitro degradation and excellent biocompatibility, which could be used as scaffolds for the bone tissue engineering.
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Affiliation(s)
- Xiaofeng Cao
- Key Laboratory of Photochemical Conversion and Optoelectronic Material, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, PR China
| | - Haojun Lu
- Hangzhou Branch of Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Zhejiang, 310018, Hangzhou, PR China
| | - Junli Liu
- Key Laboratory of Photochemical Conversion and Optoelectronic Material, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, PR China
| | - Weipeng Lu
- Key Laboratory of Photochemical Conversion and Optoelectronic Material, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, PR China
| | - Lin Guo
- Key Laboratory of Photochemical Conversion and Optoelectronic Material, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, PR China
| | - Ming Ma
- Key Laboratory of Photochemical Conversion and Optoelectronic Material, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, PR China
| | - Bing Zhang
- Key Laboratory of Photochemical Conversion and Optoelectronic Material, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, PR China
| | - Yanchuan Guo
- Key Laboratory of Photochemical Conversion and Optoelectronic Material, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, PR China.
- Hangzhou Branch of Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Zhejiang, 310018, Hangzhou, PR China.
- University of Chinese Academy of Sciences, 100049, Beijing, PR China.
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Abstract
Microbially induced calcium carbonate precipitation (MICP) is a potential method for improvement of soil. A laboratory study was conducted to investigate the influence of temperatures for soil improvement by MICP. The ureolytic activity experiments, MICP experiments in aqueous solution and sand column using Sporosarcina pasteurii were conducted at different temperatures(10, 15, 20, 25 and 30°C). The results showed there were microbially induced CaCO3 precipitation at all the temperatures from 10 to 30°C. The results of ureolytic activity experiments showed that the bacterial had higher ureolytic activity at high temperatures within the early 20 hours, however, the ureolytic activity at higher temperatures decreased more quickly than at lower temperatures. The results of MICP experiments in aqueous solution and sand column were consistent with tests of ureolytic activity. Within 20 to 50 hours of the start of the test, more CaCO3 precipitation was precipitated at higher temperature, subsequently, the precipitation rate of all experiments decreased, and the higher the temperature, the faster the precipitation rate dropped. The final precipitation amount of CaCO3 in aqueous solution and sand column tests at 10 °C was 92% and 37% higher than that at 30 °C. The maximum unconfined compressive strength of MICP treated sand column at 10 °C was 135% higher than that at 30 °C. The final treatment effect of MICP at lower temperature was better than that at high temperature within the temperature range studied. The reason for better treatment effect at lower temperatures was due to the longer retention time of ureolytic activity of bacteria at lower temperatures.
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Affiliation(s)
- Jie Peng
- Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing, Jiangsu, China
- Geotechnical Research Institute, Hohai University, Nanjing, Jiangsu, China
- * E-mail:
| | - Zhiming Liu
- Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing, Jiangsu, China
- Geotechnical Research Institute, Hohai University, Nanjing, Jiangsu, China
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Berwig KH, Baldasso C, Dettmer A. Production and characterization of poly(3-hydroxybutyrate) generated by Alcaligenes latus using lactose and whey after acid protein precipitation process. Bioresour Technol 2016; 218:31-37. [PMID: 27347795 DOI: 10.1016/j.biortech.2016.06.067] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 06/16/2016] [Accepted: 06/17/2016] [Indexed: 06/06/2023]
Abstract
Whey after acid protein precipitation was used as substrate for PHB production in orbital shaker using Alcaligenes latus. Statistical analysis determined the most appropriate hydroxide for pH neutralization of whey after protein precipitation among NH4OH, KOH and NaOH 10%w/v. The results were compared to those of commercial lactose. A scale-up test in a 4L bioreactor was done at 35°C, 750rpm, 7L/min air flow, and 6.5 pH. The PHB was characterized through Fourier Transform Infrared Spectroscopy, thermogravimetry and differential scanning calorimetry. NH4OH provided the best results for productivity (p), 0.11g/L.h, and for polymer yield, (YP/S), 1.08g/g. The bioreactor experiment resulted in lower p and YP/S. PHB showed maximum degradation temperature (291°C), melting temperature (169°C), and chemical properties similar to those of standard PHB. The use of whey as a substrate for PHB production did not affect significantly the final product quality.
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Affiliation(s)
- Karina Hammel Berwig
- Laboratory of Energy and Bioprocess, Engineering of Processes and Technology Post-Graduate Program, University of Caxias do Sul, 1130, Francisco Getúlio Vargas Street, 95070-560 Caxias do Sul, Rio Grande do Sul, Brazil
| | - Camila Baldasso
- Laboratory of Energy and Bioprocess, Engineering of Processes and Technology Post-Graduate Program, University of Caxias do Sul, 1130, Francisco Getúlio Vargas Street, 95070-560 Caxias do Sul, Rio Grande do Sul, Brazil
| | - Aline Dettmer
- Laboratory of Energy and Bioprocess, Engineering of Processes and Technology Post-Graduate Program, University of Caxias do Sul, 1130, Francisco Getúlio Vargas Street, 95070-560 Caxias do Sul, Rio Grande do Sul, Brazil.
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Punčochová K, Prajzlerová M, Beránek J, Štěpánek F. The impact of polymeric excipients on the particle size of poorly soluble drugs after pH-induced precipitation. Eur J Pharm Sci 2016; 95:138-144. [PMID: 27539142 DOI: 10.1016/j.ejps.2016.08.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 07/24/2016] [Accepted: 08/13/2016] [Indexed: 01/25/2023]
Abstract
Active pharmaceutical ingredients (APIs) with strongly pH-dependent aqueous solubility can face the problem of precipitating from solution when the pH changes from acidic in the stomach to neutral in the intestine. The present work investigates the effect of two polymeric excipients - polyvinylpyrrolidone (PVP) and Soluplus - on the ability to either prevent precipitation, or to control the size distribution of precipitated particles when precipitation cannot be prevented. Two different APIs were compared, Dabigatran etexilate mesylate and Rilpivirine hydrochloride. The effect of excipient concentration on the precipitation behaviour during pH titration was systematically investigated and qualitatively different trends were observed: in case of Soluplus, which forms a micellar solution when critical micelle concentration is exceeded, precipitation was inhibited in the case of Dabigatran etexilate, which partitioned into the micelles. On the other hand, Rilpivirine precipitated independently of Soluplus concentration. In the case of PVP, which does not form micelles, precipitation could not be avoided. Increased polymer concentration, however prevented the aggregation of precipitated particles into larger cluster. The observed effect of PVP was especially pronounced for Rilpivirine. The main conclusion of this study is that a suitably chosen polymeric excipient can either prevent precipitation altogether or reduce the size of the resulting particles. The mechanism of action, however, seems-specific to a given molecule. It was also shown that the polymer-stabilised particles have a potential to redissolve.
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Affiliation(s)
- Kateřina Punčochová
- Department of Chemical Engineering, University of Chemistry and Technology Prague, Prague 6, Czech Republic; Zentiva, k.s., U Kabelovny 130, Prague 10, Czech Republic
| | - Marie Prajzlerová
- Department of Chemical Engineering, University of Chemistry and Technology Prague, Prague 6, Czech Republic
| | - Josef Beránek
- Zentiva, k.s., U Kabelovny 130, Prague 10, Czech Republic
| | - František Štěpánek
- Department of Chemical Engineering, University of Chemistry and Technology Prague, Prague 6, Czech Republic.
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6
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Nishizawa K, Masuda T, Takenaka Y, Masui H, Tani F, Arii Y. Precipitation of sword bean proteins by heating and addition of magnesium chloride in a crude extract. Biosci Biotechnol Biochem 2016; 80:1623-31. [PMID: 27022983 DOI: 10.1080/09168451.2016.1164587] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/05/2016] [Indexed: 10/22/2022]
Abstract
Sword bean (Canavalia gladiata) seeds are a traditional food in Asian countries. In this study, we aimed to determine the optimal methods for the precipitation of sword bean proteins useful for the food development. The soaking time for sword beans was determined by comparing it with that for soybeans. Sword bean proteins were extracted from dried seeds in distilled water using novel methods. We found that most proteins could be precipitated by heating the extract at more than 90 °C. Interestingly, adding magnesium chloride to the extract at lower temperatures induced specific precipitation of a single protein with a molecular weight of approximately 48 kDa. The molecular weight and N-terminal sequence of the precipitated protein was identical to that of canavalin. These data suggested that canavalin was precipitated by the addition of magnesium chloride to the extract. Our results provide important insights into the production of processed foods from sword bean.
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Affiliation(s)
- Kaho Nishizawa
- a Department of Food Science and Nutrition , School of Human Environmental Sciences, Mukogawa Women's University , Nishinomiya , Japan
| | - Tetsuya Masuda
- b Division of Food Science and Biotechnology , Graduate School of Agriculture, Kyoto University , Uji , Japan
| | - Yasuyuki Takenaka
- c Department of Lifestyle Studies , Kobe Shoin Women's University , Kobe , Japan
| | - Hironori Masui
- a Department of Food Science and Nutrition , School of Human Environmental Sciences, Mukogawa Women's University , Nishinomiya , Japan
| | - Fumito Tani
- b Division of Food Science and Biotechnology , Graduate School of Agriculture, Kyoto University , Uji , Japan
| | - Yasuhiro Arii
- a Department of Food Science and Nutrition , School of Human Environmental Sciences, Mukogawa Women's University , Nishinomiya , Japan
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Hubbard B. Session 1.5: other viral clearance and inactivation approaches (multimodal chromatography, membrane chromatography, chemical precipitation). PDA J Pharm Sci Technol 2015; 69:173-182. [PMID: 25691725 DOI: 10.5731/pdajpst.2015.01041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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Abstract
Alcoholic precipitation is a critical step to recover RNA of high purity. This chapter describes the principles of alcoholic precipitation as well as a standard, basic protocol with key advices to observe, but numerous variations on the theme are discussed. Indeed, several important parameters, such as the choice of salt, alcohol, or carrier, have to be considered to improve the efficiency of precipitation and the yield of RNA recovery.
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Affiliation(s)
- Guillaume Clerget
- Université de Lorraine, CNRS UMR 7365 IMoPA, Biopôle, 9 avenue de la Forêt de Haye, Vandoeuvre-lès-Nancy, 54506, France
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Wang H, Dong W, Li T, Liu T. Enhanced synergistic denitrification and chemical precipitation in a modified BAF process by using Fe2+. Bioresour Technol 2014; 151:258-264. [PMID: 24246481 DOI: 10.1016/j.biortech.2013.10.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 10/10/2013] [Accepted: 10/18/2013] [Indexed: 06/02/2023]
Abstract
A series of laboratory-scale experiments for examining the feasibility and suitability of using Fe(2+) as the precipitant dosed in the pre-denitrification stage of a modified BAF process employing simultaneous chemical precipitation of TSS and phosphorus were carried out. The effects of dosing Fe(2+) on effluent quality and sludge characteristics of the pre-denitrification stage were assessed with comparing to the cases of no additional chemical dosing and dosing Fe(3+). Results obtained demonstrated a sound performance of synergistic denitrification and chemical precipitation in pre-denitrification of the modified BAF process when dosing Fe salts, which showed enhanced by using Fe(2+) as the dosed precipitant in increasing the denitrification loading rate, exhibiting a better controlling of the residual phosphorus in pre-denitrification effluent, and improving sludge settleability. Dosing Fe salt showed no adverse impact in removing COD, but resulted in a relatively higher SS content in the pre-denitrification effluent.
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Affiliation(s)
- Hongjie Wang
- Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055, PR China; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, China
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Schilcher G, Schlagenhauf A, Schneditz D, Scharnagl H, Ribitsch W, Krause R, Rosenkranz AR, Stojakovic T, Horina JH. Ethanol causes protein precipitation--new safety issues for catheter locking techniques. PLoS One 2013; 8:e84869. [PMID: 24391979 PMCID: PMC3877335 DOI: 10.1371/journal.pone.0084869] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 11/19/2013] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE The ethanol lock technique has shown great potential to eradicate organisms in biofilms and to treat or prevent central venous catheter related infections. Following instillation of ethanol lock solution, however, the inherent density gradient between blood and ethanol causes gravity induced seepage of ethanol out of the catheter and blood influx into the catheter. Plasma proteins so are exposed to highly concentrated ethanol, which is a classic agent for protein precipitation. We aimed to investigate the precipitating effect of ethanol locks on plasma proteins as a possible cause for reported catheter occlusions. METHODS Plasma samples were exposed in-vitro to ethanol (concentrations ranging from 7 to 70 v/v%) and heparin lock solutions. In catheter studies designed to mimic different in-vivo situations, the catheter tip was placed in a plasma reservoir and the material contained within the catheter was analyzed after ethanol lock instillation. The samples underwent standardized investigation for protein precipitation. RESULTS Protein precipitation was observed in plasma samples containing ethanol solutions above a concentration of 28%, as well as in material retrieved from vertically positioned femoral catheters and jugular (subclavian) catheters simulating recumbent or head down tilt body positions. Precipitates could not be re-dissolved by dilution with plasma, urokinase or alteplase. Plasma samples containing heparin lock solutions showed no signs of precipitation. CONCLUSIONS Our in-vitro results demonstrate that ethanol locks may be associated with plasma protein precipitation in central venous catheters. This phenomenon could be related to occlusion of vascular access devices locked with ethanol, as has been reported. Concerns should be raised regarding possible complications upon injection or spontaneous gravity induced leakage of such irreversibly precipitated protein particles into the systemic circulation. We suggest limiting the maximum advisable concentration of ethanol to 28 v/v% in catheter lock solutions.
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Affiliation(s)
- Gernot Schilcher
- Clinical Division of Nephrology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
- * E-mail:
| | - Axel Schlagenhauf
- Department of General Pediatrics and Adolescent Medicine, Medical University of Graz, Graz, Austria
| | - Daniel Schneditz
- Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Hubert Scharnagl
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
| | - Werner Ribitsch
- Clinical Division of Nephrology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Robert Krause
- Section of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Alexander R. Rosenkranz
- Clinical Division of Nephrology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Tatjana Stojakovic
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
| | - Joerg H. Horina
- Clinical Division of Nephrology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
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Xiao L, Yi T. [Mechanisms of hydroxypropyl methylcellulose for the precipitation inhibitor of supersaturatable self-emulsifying drug delivery systems]. Yao Xue Xue Bao 2013; 48:767-772. [PMID: 23888703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Hydroxypropyl methylcellulose (HPMC) propels self-emulsifying drug delivery systems (SEDDS) to achieve the supersaturated state in gastrointestinal tract, which possesses important significance to enhance oral absorption for poorly water-soluble drugs. This study investigated capacities and mechanisms of HPMC with different viscosities (K4M, K15M and K100M) to inhibit drug precipitation of SEDDS in the simulated gastrointestinal tract environment in vitro. The results showed that HPMC inhibited drug precipitation during the dispersion of SEDDS under gastric conditions by inhibiting the formation of crystal nucleus and the growth of crystals. HPMC had evident effects on the rate of SEDDS lipolysis and benefited the distribution of drug molecules across into the aqueous phase and the decrease of drug sediment. The mechanisms were related to the formed network of HPMC and its viscosities and molecular weight. These results offered a reference for selecting appropriate type of HPMC as the precipitation inhibitor of supersaturatable SEDDS.
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Affiliation(s)
- Lu Xiao
- State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Macau 000853, China
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12
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Lin D, Ji J, Long Z, Yang K, Wu F. The influence of dissolved and surface-bound humic acid on the toxicity of TiO₂ nanoparticles to Chlorella sp. Water Res 2012; 46:4477-87. [PMID: 22704133 DOI: 10.1016/j.watres.2012.05.035] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Revised: 04/20/2012] [Accepted: 05/21/2012] [Indexed: 05/04/2023]
Abstract
NOM is likely to coat TiO₂ nanoparticles (nano-TiO₂) discharged into the aquatic environment and influence the nanotoxicity to aquatic organisms, which however has not been well investigated. This study explored the influence of nanoparticle surface-bound humic acid (HA, as a model NOM) as well as dissolved HA on the toxicity of nano-TiO₂ to Chlorella sp., with a specific focus on adhesion of the nanoparticles to the algae. Results showed that nano-TiO₂ and the dissolved HA could inhibit the algal growth with an IC₅₀ of 4.9 and 8.4 mg L⁻¹, respectively, while both dissolved and nanoparticle surface-bound HA could significantly alleviate the algal toxicity of nano-TiO₂. IC₅₀ of nano-TiO₂ increased to 18 mg L⁻¹ in the presence of 5 mg L⁻¹ of the dissolved HA and to 48 mg L⁻¹ as the result of surface-saturation by HA. Co-precipitation experiment and transmission electron microscopy observation revealed that both dissolved and nanoparticle surface-bound HA prevented the adhesion of nano-TiO₂ to the algal cells due to the increased electrosteric repulsion. The generation of intracellular reactive oxygen species (ROS) was significantly limited by the dissolved and nanoparticle surface-bound HA. The prevention of adhesion and inhibition of ROS generation could account for the HA-mitigated nanotoxicity.
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Affiliation(s)
- Daohui Lin
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China.
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13
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Chen CK, Ju CP, Lin JHC. Setting solution concentration effect on properties of a TTCP/DCPA-derived calcium phosphate cement. J Mater Sci Mater Med 2012; 23:2109-2114. [PMID: 22689011 DOI: 10.1007/s10856-012-4700-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 05/29/2012] [Indexed: 06/01/2023]
Abstract
The present work was to investigate the effects of concentration of (NH(4))(2)HPO(4) (diammonium hydrogen phosphate) setting solution on properties of a tetracalcium phosphate (TTCP)/dicalcium phosphate anhydrous (DCPA)--derived calcium phosphate cement. Experimental results indicated that working/setting time of the cement paste decreased with increasing (NH(4))(2)HPO(4) concentration of the setting solution. After being immersed in Hanks' solution for 1 day or longer, the XRD intensities of initial TTCP and DCPA phases largely decreased, while apatite phase became dominant. More residual TTCP phase was observed in the 1 day-immersed cement prepared from higher concentration setting solutions. Compressive strength of the cement immersed for 1 day was consistently higher than that immersed for 30 min or 7 days. After being immersed for 1 day, the average CS value reached a maximal value (59 MPa) as (NH(4))(2)HPO(4) concentration was increased to 0.6 M, beyond that the cement strength decreased and maintained in a relatively high range of 47-54 MPa. Cells incubated with conditioned medium of Al(2)O(3) powder and with blank medium exhibited similar average viability values (0.80 and 0.78, respectively). The OD value with extractions of cement decreased with increasing (NH(4))(2)HPO(4) concentration of the setting solution. The average 0.25, 0.5 and 0.6 M--OD values were 0.78, 0.67 and 0.66, respectively. When setting solution concentration was greater than 0.6 M, the OD value sharply declined to 0.47.
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Affiliation(s)
- Chang-Keng Chen
- Department of Materials Science and Engineering, National Cheng-Kung University, No. 1 University Road, 70101, Tainan, Taiwan, ROC
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14
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Wang K, Mao Z, Zhang C, Zhang J, Zhang H, Tang L. Influence of nitrogen sources on ethanol fermentation in an integrated ethanol-methane fermentation system. Bioresour Technol 2012; 120:206-211. [PMID: 22804850 DOI: 10.1016/j.biortech.2012.06.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 05/17/2012] [Accepted: 06/14/2012] [Indexed: 06/01/2023]
Abstract
An integrated ethanol-methane fermentation system was proposed to resolve wastewater pollution in cassava ethanol production. In the integrated system, wastewater originating from ethanol distillation was treated by two-stage anaerobic digestion and then used in medium for the next batch of ethanol fermentation. Ammonium and other components in the effluent promoted yeast growth and fermentation rate but did not increase the yield of ethanol. Fermentations with the effluent as the nitrogen source showed higher growth and ethanol production rates (0.215 h(-1) and 1.276 g/L/h, respectively) than urea that resulted in corresponding rates of 0.176 h(-1) and 0.985 g/L/h, respectively. Results indicated that anaerobic digestion effluent can be used as nitrogen source for the ethanol fermentation instead of urea in the ethanol-methane fermentation system.
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Affiliation(s)
- Ke Wang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
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15
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Lu Y, Cheng X, Xing B, Sun ZE, Sun DZ. [Influence of reaction time of urea hydrolysis-based co-precipitation on the structure of ZnAl layered double hydroxides and the phosphate adsorption]. Huan Jing Ke Xue 2012; 33:2868-2874. [PMID: 23213917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A series of ZnAl layered double hydroxides (LDHs) were prepared by urea hydrolysis-based homogeneous co-precipitation for studying their structure and phosphate adsorption capacities. The results show that all the samples exhibited a typical layered structure as the reaction time extended from 12 h to 96 h, whereas Zn/Al molar ratio in the ZnAls decreased from 2.06 to 0.70 and the specific surface area markedly increased to be 7.6-fold higher than that of ZnAl-12. Phosphate adsorption capacity of the ZnAl was in general increased gradually with the reaction time extension, which can be attributed to the surface area rising as well as the increased positive charge of LDHs layer caused by a higher proportion of Al. This reveals that physicochemical adsorption on LDHs surface would have played an important role during the phosphate adsorption. With a reaction time of 24 h, a high amount of exchangeable interlayer anions was observed, giving rise to a highest phosphate uptake of 34.1 mg x g(-1) by the ZnAl-24. It indicates the ion exchange was another major pathway for the phosphate removal. For all the ZnAls with different reaction times, the phosphate adsorption isotherms fit well with Langmuir-type equations; the adsorption kinetics followed pseudo-second-order models.
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Affiliation(s)
- Ying Lu
- College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
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16
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Huang CC, Hung JJ, Peng SH, Chen CNN. Cultivation of a thermo-tolerant microalga in an outdoor photobioreactor: influences of CO2 and nitrogen sources on the accelerated growth. Bioresour Technol 2012; 112:228-233. [PMID: 22414576 DOI: 10.1016/j.biortech.2012.02.078] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 02/12/2012] [Accepted: 02/16/2012] [Indexed: 05/31/2023]
Abstract
A photobioreactor was designed to evaluate the performance of a newly isolated thermo-tolerant microalga Desmodesmus sp. F2 in municipal wastewater under tropical outdoor conditions. The environmental parameters, levels of nutrients, and growth rates were monitored during the cultivations to elucidate the factors that contributed to accelerated growth after lag phase. Cultures bubbled with CO(2)-air had about 20% higher yields than the air-bubbled culture, and 2% of CO(2) at a flux rate of 5L/min was sufficient to reach this increased yield. In the cultures bubbled with CO(2)-air, the microalgal cells preferentially utilized ammonium and nitrate, while the air-bubbled culture made greater use of ammonium and organic nitrogen. In conclusion, the factors required for microalga Desmodesmus sp. F2 to achieve accelerated growth in tropical outdoor conditions include (1) 2% CO(2) bubbling; (2) a level of ammonium higher than 100 μM; and (3) a level of nitrate higher than 400 μM.
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Affiliation(s)
- Chai-Cheng Huang
- Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung 804, Taiwan
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17
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Egüés I, Sanchez C, Mondragon I, Labidi J. Effect of alkaline and autohydrolysis processes on the purity of obtained hemicelluloses from corn stalks. Bioresour Technol 2012; 103:239-248. [PMID: 22029960 DOI: 10.1016/j.biortech.2011.09.139] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 09/12/2011] [Accepted: 09/30/2011] [Indexed: 05/31/2023]
Abstract
A study of the potential of autohydrolysis and alkaline extraction processes from corn stalks was performed for high purity hemicellulose extraction. The influence of process parameters on the purity of obtained hemicelluloses was analyzed. An experimental design was developed for the autohydrolysis treatments to determine the optimal conditions to solubilize the hemicelluloses with lowest content in contaminants. On the other hand, alkaline extraction, including raw material pretreatment (dewaxing and delignification step) was carried out analyzing the effectiveness of this processes for maximum pure hemicellulose recovery. The maximum yield (54% of the raw material hemicelluloses) and the best physicochemical properties (highest hemicellulose content free of lignin) were obtained with these pretreatments in alkaline extraction. Moreover, the effect of lignin removal by sulfuric acid from the autohydrolysis liquors before hemicellulose precipitation was studied. This purification step has allowed to obtain lignin-free autohydrolysis hemicellulose but with the presence of sulfur as predominant contaminant.
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Affiliation(s)
- Itziar Egüés
- Chemical and Environmental Engineering Department, University of the Basque Country, Plaza Europa 1, 20018 Donostia-San Sebastián, Spain
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18
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Govind CK, Ginsburg D, Hinnebusch AG. Measuring dynamic changes in histone modifications and nucleosome density during activated transcription in budding yeast. Methods Mol Biol 2012; 833:15-27. [PMID: 22183585 PMCID: PMC3610330 DOI: 10.1007/978-1-61779-477-3_2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Chromatin immunoprecipitation is widely utilized to determine the in vivo binding of factors that regulate transcription. This procedure entails formaldehyde-mediated cross-linking of proteins and isolation of soluble chromatin followed by shearing. The fragmented chromatin is subjected to immunoprecipitation using antibodies against the protein of interest and the associated DNA is identified using quantitative PCR. Since histones are posttranslationally modified during transcription, this technique can be effectively used to determine the changes in histone modifications that occur during transcription. In this paper, we describe a detailed methodology to determine changes in histone modifications in budding yeast that takes into account reductions in nucleosome.
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Affiliation(s)
- Chhabi K Govind
- Department of Biological Sciences, Oakland University, Rochester, MI, USA.
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19
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Kornblatt MJ, Kornblatt JA, Hancock MA. The interaction of canine plasminogen with Streptococcus pyogenes enolase: they bind to one another but what is the nature of the structures involved? PLoS One 2011; 6:e28481. [PMID: 22174817 PMCID: PMC3235116 DOI: 10.1371/journal.pone.0028481] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 11/09/2011] [Indexed: 12/02/2022] Open
Abstract
For years it has been clear that plasminogen from different sources and enolase from different sources interact strongly. What is less clear is the nature of the structures required for them to interact. This work examines the interaction between canine plasminogen (dPgn) and Streptococcus pyogenes enolase (Str enolase) using analytical ultracentrifugation (AUC), surface plasmon resonance (SPR), fluorescence polarization, dynamic light scattering (DLS), isothermal titration calorimetry (ITC), and simple pull-down reactions. Overall, our data indicate that a non-native structure of the octameric Str enolase (monomers or multimers) is an important determinant of its surface-mediated interaction with host plasminogen. Interestingly, a non-native structure of plasminogen is capable of interacting with native enolase. As far as we can tell, the native structures resist forming stable mixed complexes.
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20
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Mellinger-Silva C, Simas-Tosin FF, Schiavini DN, Werner MF, Baggio CH, Pereira IT, da Silva LM, Gorin PAJ, Iacomini M. Isolation of a gastroprotective arabinoxylan from sugarcane bagasse. Bioresour Technol 2011; 102:10524-10528. [PMID: 21945160 DOI: 10.1016/j.biortech.2011.08.107] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 08/18/2011] [Accepted: 08/25/2011] [Indexed: 05/31/2023]
Abstract
After industrial processing, one-third of sugarcane culms is converted into residual bagasse. The xylan-rich hemicellulose components of the bagasse were extracted with hot aqueous alkali (AX-CRUDE). Approximately 82% of the extracted hemicelluloses was precipitated with ethanol (AX-PET). Both AX-CRUDE and AX-PET contained an arabinoxylan as confirmed by 13C NMR and methylation analysis. Fraction AX-PET was fed to female Wistar rats with ethanol-induced gastric lesions. Oral administrations of 30, 100, and 300 mg/kg reduced the gastric lesion area by over 50%, and replenished ethanol-induced depletion of glutathione. The polysaccharide also increased mucus production by over 70%, indicating its cytoprotective action on experimentally induced gastric ulcers. These findings are significant, since a biologically active compound can be extracted in high yields from an abundant, readily available residue.
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Affiliation(s)
- Caroline Mellinger-Silva
- Embrapa Agroindústria de Alimentos, Av. das Américas, 29501, 23.020-470 Rio de Janeiro, RJ, Brazil.
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21
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Zhang LZ, Chen XD, Ma J, Yu M, Li X. [Effects on phenol removal in the process of enhanced coagulation by manganese dioxide formed in situ]. Huan Jing Ke Xue 2011; 32:2926-2930. [PMID: 22279903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Phenol was selected as a model compound. Factors, such as Ca2+, tannic acid, dose of kaolinite, dose of manganese dioxide formed in situ and pH, were invested on phenol removal in the process of enhanced coagulation by manganese dioxide formed in situ. Results showed that the addition of Ca2+ is beneficial for phenol removal. In the range of Ca2+ varied from 0 to 1.0 mmol x L(-1), the efficiency of phenol removal was enhanced more than 10%. Tannic acid can enhance phenol removal significantly when they are coexisted in water. As tannic acid was added to 10 mg x L(-1), phenol removal can be increased about 30% and 50% in the process of coagulation by AlCl3 and enhanced coagulation by manganese dioxide formed in situ, respectively. The dose of coagulant can be reduced in the process of enhanced coagulation with the addition of manganese dioxide formed in situ. The point of 1 mg x L(-1) manganese dioxide formed in situ linked with 30 mg x L(-1) AlCl3 can have the same phenol removal efficiency as the addition of 50 mg x L(-1) AlCl3. In the range of pH varied from 5 to 9, phenol can be removed with the high efficiency in the process of enhanced coagulation by manganese dioxide formed in situ. While under the strong acid condition and strong basic condition, phenol has lower removal efficiency.
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Affiliation(s)
- Li-Zhu Zhang
- Department of Chemistry of Science School, Harbin Institute of Technology, Harbin 150001, China.
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22
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Karagoz B, Bayramoglu G, Altintas B, Bicak N, Arica MY. Amine functional monodisperse microbeads via precipitation polymerization of N-vinyl formamide: immobilized laccase for benzidine based dyes degradation. Bioresour Technol 2011; 102:6783-6790. [PMID: 21531131 DOI: 10.1016/j.biortech.2011.03.050] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2011] [Revised: 03/10/2011] [Accepted: 03/16/2011] [Indexed: 05/30/2023]
Abstract
Densely cross-linked poly(vinylamine) microbeads (∼ 2 μm) were prepared by precipitation copolymerization of N-vinyl formamide and ethylene glycoldimethacrylate in acetonitrile. The formamido groups of the microbeads were hydrolyzed into amino groups. Then, amino-functionalized microbeads were used for covalent immobilization of laccase via glutaraldehyde coupling. The average amount of immobilized enzyme was 18.7 mg/g microbeads. Kinetic parameters, V(max) and K(m) values were determined as 20.7 U/mg protein and 2.76 × 10(-2)mmol/L for free enzyme and 15.8 U/mg protein and 4.65 mmol/L for the immobilized laccase, respectively. The immobilized laccase was operated in a batch reactor for the degradation of two different benzidine based dyes (i.e., Direct Blue 1 and Direct Red 128). The laccase immobilized on the microbeads was very effective for removal of these dyes which interfere with the hormonal system.
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Affiliation(s)
- Bunyamin Karagoz
- Istanbul Technical University, Department of Chemistry, Maslak 34469, Istanbul, Turkey
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23
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Imbuluzqueta E, Elizondo E, Gamazo C, Moreno-Calvo E, Veciana J, Ventosa N, Blanco-Prieto MJ. Novel bioactive hydrophobic gentamicin carriers for the treatment of intracellular bacterial infections. Acta Biomater 2011; 7:1599-608. [PMID: 21115143 DOI: 10.1016/j.actbio.2010.11.031] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Revised: 11/22/2010] [Accepted: 11/22/2010] [Indexed: 11/28/2022]
Abstract
Gentamicin (GEN) is an aminoglycoside antibiotic with a potent antibacterial activity against a wide variety of bacteria. However, its poor cellular penetration limits its use in the treatment of infections caused by intracellular pathogens. One potential strategy to overcome this problem is the use of particulate carriers that can target the intracellular sites of infection. In this study GEN was ion-paired with the anionic AOT surfactant to obtain a hydrophobic complex (GEN-AOT) that was formulated as a particulated material either by the precipitation with a compressed antisolvent (PCA) method or by encapsulation into poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs). The micronization of GEN-AOT by PCA yielded a particulated material with a higher surface area than the non-precipitated complex, while PLGA NPs within a size range of 250-330 nm and a sustained release of the drug over 70 days were obtained by preparing the NPs using the emulsion solvent evaporation method. For the first time, GEN encapsulation efficiency values of ∼100% were achieved for the different NP formulations with no signs of interaction between the drug and the polymer. Finally, in vitro studies against the intracellular bacteria Brucella melitensis, used as a model of intracellular pathogen, demonstrated that the bactericidal activity of GEN was unmodified after ion-pairing, precipitation or encapsulation into NPs. These results encourage their use for treatment for infections caused by GEN-sensitive intracellular bacteria.
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Affiliation(s)
- Edurne Imbuluzqueta
- Department of Pharmacy and Pharmaceutical Technology, University of Navarra, Pamplona, Spain
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24
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Dittrich M, Gabriel O, Rutzen C, Koschel R. Lake restoration by hypolimnetic Ca(OH)2 treatment: impact on phosphorus sedimentation and release from sediment. Sci Total Environ 2011; 409:1504-1515. [PMID: 21292312 DOI: 10.1016/j.scitotenv.2011.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 01/05/2011] [Accepted: 01/05/2011] [Indexed: 05/30/2023]
Abstract
A whole-lake hypolimnetic Ca(OH)(2) addition, that induced calcium carbonate precipitation, combined with deep water aeration has been applied to eutrophic Lake Luzin, Germany during 1996-1998. In this study we investigated the dynamic of phosphorus and its binding forms in seston and sediment before and during the treatment. The sedimentation rates of phosphorus increased within three years of induced calcite precipitation. The phosphorus binding forms shifted to the calcite-bound phosphorus in the settling matter. The increase of calcite-bound P in the settling material did not coincide with the maximum induced CaCO(3)-precipitation caused by the hypolimnetic addition of Ca(OH)(2). An impact of chemicals additions and pH on phosphorus binding forms in seston and surface sediments has been studied in laboratory experiments with sediment core incubations and slurry experiments. Laboratory studies showed that the lowest phosphorus flux from sediment was related to the experiment with pH=7 in overlaying water adjusted with Ca(OH)(2). The adjusting of pH with Ca(OH)(2) leads to a lower P flux of 2.3 mg Pm(-2)d(-1), while the highest P-flux is attributed to the experiment with the pH which was adjusted with NaOH. Phosphorus fraction which reflects phosphorus binding on carbonates in surface sediments increased within one year of treatment, enhancing the phosphorus retention capacity of sediments.
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Affiliation(s)
- Maria Dittrich
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Canada.
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25
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Buker SM, Motamedi MR. Purification of native Argonaute complexes from the fission yeast Schizosaccharomyces pombe. Methods Mol Biol 2011; 725:1-13. [PMID: 21528443 DOI: 10.1007/978-1-61779-046-1_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Small interfering (si) RNAs, produced by the RNA interference (RNAi)-mediated processing of long double-stranded (ds) RNAs, can inhibit gene expression by post-transcriptional or transcriptional gene silencing mechanisms. At the heart of all small RNA-mediated silencing lies the key RNAi effector protein Argonaute, which once loaded with small RNAs can recognize its target transcript by siRNA-RNA Watson-Crick base pairing interactions. In the fission yeast Schizosaccharomyces pombe, the formation of the epigenetically heritable centromeric heterochromatin requires RNAi proteins including the sole fission yeast Argonaute homolog, Ago1. Two distinct native Ago1 complexes have been purified and studied extensively, both of which are required for siRNA production and heterochromatin formation at the fission yeast centromeres. The purification and analysis of the Argonaute siRNA chaperone (ARC) complex and RNA-induced transcriptional silencing (RITS) complex have provided insight into the mechanism of siRNA-Ago1 loading and the cis recruitment of silencing complexes at fission yeast centromeres, respectively. These discoveries have been instrumental in shaping the current models of RNA-mediated epigenetic silencing in eukaryotes. Below, we describe the protocol used for affinity purification of the native Ago1 complexes from S. pombe.
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Affiliation(s)
- Shane M Buker
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
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26
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Li H, Hsieh MK, Chien SH, Monnell JD, Dzombak DA, Vidic RD. Control of mineral scale deposition in cooling systems using secondary-treated municipal wastewater. Water Res 2011; 45:748-760. [PMID: 20851443 DOI: 10.1016/j.watres.2010.08.052] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Revised: 08/19/2010] [Accepted: 08/30/2010] [Indexed: 05/29/2023]
Abstract
Secondary-treated municipal wastewater (MWW) is a promising alternative to freshwater as power plant cooling system makeup water, especially in arid regions. A prominent challenge for the successful use of MWW for cooling is potentially severe mineral deposition (scaling) on pipe surfaces. In this study, theoretical, laboratory, and field work was conducted to evaluate the mineral deposition potential of MWW and its deposition control strategies under conditions relevant to power plant cooling systems. Polymaleic acid (PMA) was found to effectively reduce scale formation when the makeup water was concentrated four times in a recirculating cooling system. It was the most effective deposition inhibitor of those studied when applied at 10 mg/L dosing level in a synthetic MWW. However, the deposition inhibition by PMA was compromised by free chlorine added for biogrowth control. Ammonia present in the wastewater suppressed the reaction of the free chlorine with PMA through the formation of chloramines. Monochloramine, an alternative to free chlorine, was found to be less reactive with PMA than free chlorine. In pilot tests, scaling control was more challenging due to the occurrence of biofouling even with effective control of suspended bacteria. Phosphorous-based corrosion inhibitors are not appropriate due to their significant loss through precipitation reactions with calcium. Chemical equilibrium modeling helped with interpretation of mineral precipitation behavior but must be used with caution for recirculating cooling systems, especially with use of MWW, where kinetic limitations and complex water chemistries often prevail.
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Affiliation(s)
- Heng Li
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
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27
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Shahid S, Billington RW, Hill RG, Pearson GJ. The effect of ultrasound on the setting reaction of zinc polycarboxylate cements. J Mater Sci Mater Med 2010; 21:2901-2905. [PMID: 20717709 DOI: 10.1007/s10856-010-4146-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Accepted: 08/03/2010] [Indexed: 05/29/2023]
Abstract
The set of glass ionomer cement (GIC) is accelerated by application of ultrasound. Although GIC has somewhat displaced zinc polycarboxylate cement (ZPC) in dental applications the latter is still extensively used. Like GIC, it provides direct adhesion to tooth and can provide F release, but is more radiopaque and biocompatible than GIC. The aim of this study is to examine the effect of ultrasound on the setting of ZPC using Fourier transform infra red spectroscopy and any interaction with SnF(2) addition. ZPC with and without SnF(2) addition (+/-S) at luting (L) 2:1 P/L ratio and restorative (R) 4:1 P/L ratio consistencies. Ultrasound is applied to the cement using Piezon-Master 400, EMS, Switzerland at 60 s from start of mixing for 15 s. The ratios of absorbance peak height at 1,400 cm(-1) -COO(-) to that at 1,630 cm(-1) -COOH were measured and compared those obtained for the cement not treated with US. These values were taken at the elapsed time at which no further change in spectrum [ratio] was observed at room temperature [10-20 min]. The US results are taken at 2 or 3 min. No US: R/+S (1.09), R/-S (1.2), L/+S (1.07), L/-S (1.04); US: R/+S (1.50), R/-S (1.64), L/+S (1.38), L/-S (1.05). The results show all four ZPC formulations are very sensitive to ultrasound whether with or without SnF(2). Reducing US to 10 s produces lower initial ratios but these increase up to 10 min when very high ratios (>2) are obtained. Previous studies with restorative GICs found that 40-55 s US was needed to produce the effect found with 15 s on ZPCs. ZPC powder is more basic than GIC glass; this may account for ZPC's greater sensitivity to US. Ultrasound may provide a useful adjunct to the clinical use of ZPC both as luting agent and temporary restorative.
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Affiliation(s)
- S Shahid
- Department of Dental Physical Sciences, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, Francis Bancroft Building, Mile End, London E1 4NS, UK.
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28
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Cho JH, Cho MH, Hwang H, Bhoo SH, Hahn TR. Improvement of plant protein solubilization and 2-DE gel resolution through optimization of the concentration of Tris in the solubilization buffer. Mol Cells 2010; 29:611-6. [PMID: 20496115 DOI: 10.1007/s10059-010-0076-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 03/02/2010] [Accepted: 03/03/2010] [Indexed: 10/19/2022] Open
Abstract
It is important to solubilize acetone-precipitated proteins before isoelectric focusing (IEF) to achieve high resolution 2-DE gels. To resolve the maximum possible number of plant protein spots, we developed an improved solubilization buffer for plant proteins. We demonstrated that the resolution of 2-DE gels increased dramatically as the concentration of Tris-base increased, with maximum solubilization obtained at 200 mM Tris-base (Ly200T). The Ly200T buffer was more effective than the commonly used solubilization buffer containing 40 mM Tris at solubilizing acetone-precipitated plant proteins. Use of the Ly200T buffer to solubilize proteins resulted in an increase in intensity of approximately 30% of plant protein spots in the larger-than-40 kDa region of the gel. The Ly200T buffer also improved the resolution of abundant and basic proteins. Thus, the Ly200T buffer can be used to achieve greater resolution of protein spots in plant proteomics research.
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Affiliation(s)
- Jin-Hwan Cho
- Graduate School of Biotechnology and Plant Metabolism Research Center, Kyung Hee University, Suwon, 446-701, Korea
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29
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Hsu HF, Jhuo YS, Kumar M, Ma YS, Lin JG. Simultaneous sulfate reduction and copper removal by a PVA-immobilized sulfate reducing bacterial culture. Bioresour Technol 2010; 101:4354-4361. [PMID: 20153634 DOI: 10.1016/j.biortech.2010.01.094] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Revised: 01/19/2010] [Accepted: 01/21/2010] [Indexed: 05/28/2023]
Abstract
The effect of a sulfate reducing bacteria immobilized in polyvinyl alcohol (PVA) on simultaneous sulfate reduction and copper removal was investigated. Batch experiments were designed using central composite design (CCD) with two parameters, i.e. the copper concentration (10-100mg/L), and the quantity of immobilized SRB in culture solution (19-235 mg of VSS/L). Response surface methodology (RSM) was used to model the experimental data, and to identify optimal conditions for the maximum sulfate reduction and copper removal. Under optimum condition, i.e. approximately 138.5mg VSS/L of sulfate reducing bacteria immobilized in PVA, and approximately 51.5mg/L of copper, the maximum sulfate reduction rate was 1.57 d(-1) as based on the first-order kinetic equation. The data demonstrate that immobilizing sulfate reducing bacteria in PVA can enhance copper removal and the resistance of the bacteria towards copper toxicity.
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Affiliation(s)
- Hsiu-Feng Hsu
- Institute of Environmental Engineering, National Chiao Tung University, 1001, University Road, Hsinchu, Taiwan
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30
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Chauhan CK, Joshi MJ, Vaidya ADB. Growth inhibition of struvite crystals in the presence of herbal extract Commiphora wightii. J Mater Sci Mater Med 2009; 20 Suppl 1:S85-S92. [PMID: 18568390 DOI: 10.1007/s10856-008-3489-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Accepted: 05/28/2008] [Indexed: 05/26/2023]
Abstract
Struvite is one of the components of urinary stone. Large number of people is suffering from urinary stones (calculi) problem all over the globe. These stones can grow rapidly forming "staghorn-calculi", which is more painful urological disorder. Therefore, it is of prime importance to study the growth and inhibition of Struvite crystals. This in vitro study has been carried out in the presence of herbal extract of Commiphora wightii by using single diffusion gel growth technique. Sodium metasilicate solution of specific gravity 1.05 and an aqueous solution of ammonium dihydrogen phosphate of 0.5 M concentration were mixed so that the pH value 7.0 could be set. After the gelation, equal amount of supernatant solutions comprising of pure 1.0 M magnesium acetate as well as the mixtures of magnesium acetate and the herbal extract solutions of 0.5 and 1% concentrations of C. wightii were gently poured on the set gels. From the study of growth and inhibition behavior of Struvite crystals, it was found that C. wightii inhibits the growth of the Struvite. This study incorporates multidisciplinary interests and may be used for formulating the strategy for prevention or dissolution of urinary stones.
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Affiliation(s)
- C K Chauhan
- Crystal Growth Laboratory, Department of Physics, Saurashtra University, Rajkot 360 005, Gujarat, India.
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Zhang YJ, Zhou LL, Li WY, Li X, Li DQ, Li GB. [Mechanism of natural organic matter removal by potassium permanganate composite enhanced coagulation]. Huan Jing Ke Xue 2009; 30:761-764. [PMID: 19432324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Streaming current technique, fluctuation of transmitted light technique, molecular weight distribution and XAD resin adsorption technique were used to study the mechanism of natural organic matter removal by potassium permanganate composite (PPC) enhanced coagulation. Results showed that natural organic matter removal efficiency increased 13% by 0.75 mg/L potassium permanganate composite enhanced coagulation compared with that of alum coagulation alone. Streaming current indicated that potassium permanganate composite decreased the organic matter stability by reducing the surface negative charge, and the SC value increased from 55.2 to 61.4, 69.6 and 87.0 by addition of 0.50, 0.75 and 1.0 mg/L PPC. Coagulation index R indicated both nascent manganese dioxide and subsidiaries played an important role in potassium permanganate composite enhanced coagulation process. Potassium permanganate composite enhanced coagulation increased the removal efficiency of lower molecular weight and hydrophilic organic matter compared with alum coagulation, and hydrophilic organic matter can be reduced from 1.9 mg/L to 1.32 mg/L by the addition of 0.75 mg/L potassium permanganate composite.
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Affiliation(s)
- Yong-Ji Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China.
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