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Sample records for sirna purification process

  1. Development of partitioning process: purification of DIDPA

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Masayuki; Morita, Yasuji; Kubota, Masumitsu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-04-01

    The partitioning process has developed and demonstrated that the solvent extraction with diisodecylphosphoric acid (DIDPA) can successfully separate transuranium elements from a high-level liquid waste. In the solvent extraction, DIDPA is decomposed by radiolysis and hydrolysis. The main degradation product is monoisodecyl phosphoric acid (MIDPA). Ethylene glycol has been used for removing the product by a solvent extraction method. However this method has two drawbacks that two phases separate slowly and the used ethylene glycol is not regeneratable. First it was found that the addition of acetone or methanol with 20 volume % improved the phase separation. Then a new purification method was developed by using an aqueous solution of methanol or acetone. The new purification method is as excellent as the ethylene glycol method for the removal of MIDPA. (author)

  2. Deep Sequencing Insights in Therapeutic shRNA Processing and siRNA Target Cleavage Precision.

    Science.gov (United States)

    Denise, Hubert; Moschos, Sterghios A; Sidders, Benjamin; Burden, Frances; Perkins, Hannah; Carter, Nikki; Stroud, Tim; Kennedy, Michael; Fancy, Sally-Ann; Lapthorn, Cris; Lavender, Helen; Kinloch, Ross; Suhy, David; Corbau, Romu

    2014-02-04

    TT-034 (PF-05095808) is a recombinant adeno-associated virus serotype 8 (AAV8) agent expressing three short hairpin RNA (shRNA) pro-drugs that target the hepatitis C virus (HCV) RNA genome. The cytosolic enzyme Dicer cleaves each shRNA into multiple, potentially active small interfering RNA (siRNA) drugs. Using next-generation sequencing (NGS) to identify and characterize active shRNAs maturation products, we observed that each TT-034-encoded shRNA could be processed into as many as 95 separate siRNA strands. Few of these appeared active as determined by Sanger 5' RNA Ligase-Mediated Rapid Amplification of cDNA Ends (5-RACE) and through synthetic shRNA and siRNA analogue studies. Moreover, NGS scrutiny applied on 5-RACE products (RACE-seq) suggested that synthetic siRNAs could direct cleavage in not one, but up to five separate positions on targeted RNA, in a sequence-dependent manner. These data support an on-target mechanism of action for TT-034 without cytotoxicity and question the accepted precision of substrate processing by the key RNA interference (RNAi) enzymes Dicer and siRNA-induced silencing complex (siRISC).Molecular Therapy-Nucleic Acids (2014) 3, e145; doi:10.1038/mtna.2013.73; published online 4 February 2014.

  3. Process for purification of gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, S Z; Letitschevskij, V I; Maergojz, I I; Michailov, L A; Puschkarev, L I

    1977-06-23

    The process relates to the purification of gas mixtures of N, H, and Ar, or N and H, or N and O which contain CO, CO/sub 2/ and water vapour. Single-stage adsorption occurs under standard pressure at temperatures from -40 to +4/sup 0/C up to the point of CO penetration through the zeolite layer. Zeolite is of type A or X combined with Ca, Na, Ag, Cd, Co, Ni, Mn or a natural zeolite of the type klinoptilolite. Regeneration is achieved at constant temperature and pressure of 1-5x10/sup -1/ Torr or by heating to 120-600/sup 0/C.

  4. PLUTONIUM PURIFICATION PROCESS EMPLOYING THORIUM PYROPHOSPHATE CARRIER

    Science.gov (United States)

    King, E.L.

    1959-04-28

    The separation and purification of plutonium from the radioactive elements of lower atomic weight is described. The process of this invention comprises forming a 0.5 to 2 M aqueous acidffc solution containing plutonium fons in the tetravalent state and elements with which it is normally contaminated in neutron irradiated uranium, treating the solution with a double thorium compound and a soluble pyrophosphate compound (Na/sub 4/P/sub 2/O/sub 7/) whereby a carrier precipitate of thorium A method is presented of reducing neptunium and - trite is advantageous since it destroys any hydrazine f so that they can be removed from solutions in which they are contained is described. In the carrier precipitation process for the separation of plutonium from uranium and fission products including zirconium and columbium, the precipitated blsmuth phosphate carries some zirconium, columbium, and uranium impurities. According to the invention such impurities can be complexed and removed by dissolving the contaminated carrier precipitate in 10M nitric acid, followed by addition of fluosilicic acid to about 1M, diluting the solution to about 1M in nitric acid, and then adding phosphoric acid to re-precipitate bismuth phosphate carrying plutonium.

  5. Surface processes during purification of InP quantum dots

    Directory of Open Access Journals (Sweden)

    Natalia Mordvinova

    2014-08-01

    Full Text Available Recently, a new simple and fast method for the synthesis of InP quantum dots by using phosphine as phosphorous precursor and myristic acid as surface stabilizer was reported. Purification after synthesis is necessary to obtain samples with good optical properties. Two methods of purification were compared and the surface processes which occur during purification were studied. Traditional precipitation with acetone is accompanied by a small increase in photoluminescence. It occurs that during the purification the hydrolysis of the indium precursor takes place, which leads to a better surface passivation. The electrophoretic purification technique does not increase luminescence efficiency but yields very pure quantum dots in only a few minutes. Additionally, the formation of In(OH3 during the low temperature synthesis was explained. Purification of quantum dots is a very significant part of postsynthetical treatment that determines the properties of the material. But this subject is not sufficiently discussed in the literature. The paper is devoted to the processes that occur at the surface of quantum dots during purification. A new method of purification, electrophoresis, is investigated and described in particular.

  6. Purification

    DEFF Research Database (Denmark)

    Andersen, Astrid Oberborbeck

    2017-01-01

    In Arequipa, Peru’s second largest city, engineers work hard to control water flows and provide different sectors with clean and sufficient water. In 2011, only 10 percent of the totality of water used daily by Arequipa’s then close to 1 million people—in households, tourism, industry, and mining......—was treated before it was returned to the river where it continues its flow downstream towards cultivated fields and, finally, into the Pacific Ocean. It takes specialized knowledge and manifold technologies to manage water and sustain life in Arequipa, and engineers are central actors for making water flow...... of categories can be understood as practices of purification. However, a purely technical grip on water is never possible. Unruly elements, like weather, contamination, urban dwellers, and competing interests, interfere and make processes of intervention unstable. Water is never completely cleaned, and, equally...

  7. Rational and systematic protein purification process development: the next generation.

    Science.gov (United States)

    Nfor, Beckley K; Verhaert, Peter D E M; van der Wielen, Luuk A M; Hubbuch, Jürgen; Ottens, Marcel

    2009-12-01

    Current biopharmaceutical manufacturing strongly relies on using purification platform processes, offering harmonization of practices and speed-to-market. However, the ability of such processes to respond quickly to anticipated higher quality and capacity demands is under question. Here, we describe novel approaches for purification process development that incorporate biothermodynamics, modern high throughput experimentation and simulation tools. Such development leads to production platform-specific databases containing thermodynamic protein descriptors of major host cell proteins over a range of experimental conditions. This will pave the way for in silico purification process development, providing better process understanding and the potential to respond quickly to product quality and market demands. Future efforts will focus on improving this field further and enabling more rationale in process development.

  8. A low inventory adsorptive process for tritium extraction and purification

    International Nuclear Information System (INIS)

    Keefer, B.; Bora, B.; Chew, M.; Rump, M.; Kveton, O.K.

    1990-08-01

    The fuel cycles of future fusion power systems present a diverse spectrum of challenges to gas separation technology, for extraction, concentration, purification and confinement of tritium in fusion fuel cycles. Economic and safety factors motivate process design for minimum tritium inventory, functional simplicity, and overall reliability. A new gas separation process with some features of interest to fusion has been demonstrated under the auspices of the Canadian Fusion Fuels Technology Project. This process (Thermally Coupled Pressure Swing Adsorption or 'TCPSA') is potentially applicable to several fusion applications for separation purification of hydrogen, notably for tritium extraction from breeder blanket purge helium. Recent experimental tests have been directed toward fusion applications, primarily extraction and concentration of tritium-rich hydrogen from the blanket purge helium stream, and also considering purification of this and other hydrogen isotope streams such as the plasma exhaust. For example, hydrogen at 0.1% concentration in helium has been extracted in a TCPSA module operating at 195 K, with the process performed in a single working space to achieve simultaneous high extraction and concentration of the hydrogen. With methane or carbon oxides as the impurities, substantially complete separation is achieved by the same apparatus at ambient temperature. Engineering projections for scale-up to ITER blanket purge extraction and purification applications indicate a low working inventory of tritium

  9. Assorted Processing of Synthetic Trans-Acting siRNAs and Its Activity in Antiviral Resistance.

    Science.gov (United States)

    Zhao, Mingmin; San León, David; Mesel, Frida; García, Juan Antonio; Simón-Mateo, Carmen

    2015-01-01

    The use of syn-tasiRNAs has been proposed as an RNA interference technique alternative to those previously described: hairpin based, virus induced gene silencing or artificial miRNAs. In this study we engineered the TAS1c locus to impair Plum pox virus (PPV) infection by replacing the five native siRNAs with two 210-bp fragments from the CP and the 3´NCR regions of the PPV genome. Deep sequencing analysis of the small RNA species produced by both constructs in planta has shown that phased processing of the syn-tasiRNAs is construct-specific. While in syn-tasiR-CP construct the processing was as predicted 21-nt phased in register with miR173-guided cleavage, the processing of syn-tasiR-3NCR is far from what was expected. A 22-nt species from the miR173-guided cleavage was a guide of two series of phased small RNAs, one of them in an exact 21-nt register, and the other one in a mixed of 21-/22-nt frame. In addition, both constructs produced abundant PPV-derived small RNAs in the absence of miR173 as a consequence of a strong sense post-transcriptional gene silencing induction. The antiviral effect of both constructs was also evaluated in the presence or absence of miR173 and showed that the impairment of PPV infection was not significantly higher when miR173 was present. The results show that syn-tasiRNAs processing depends on construct-specific factors that should be further studied before the so-called MIGS (miRNA-induced gene silencing) technology can be used reliably.

  10. Assorted Processing of Synthetic Trans-Acting siRNAs and Its Activity in Antiviral Resistance.

    Directory of Open Access Journals (Sweden)

    Mingmin Zhao

    Full Text Available The use of syn-tasiRNAs has been proposed as an RNA interference technique alternative to those previously described: hairpin based, virus induced gene silencing or artificial miRNAs. In this study we engineered the TAS1c locus to impair Plum pox virus (PPV infection by replacing the five native siRNAs with two 210-bp fragments from the CP and the 3´NCR regions of the PPV genome. Deep sequencing analysis of the small RNA species produced by both constructs in planta has shown that phased processing of the syn-tasiRNAs is construct-specific. While in syn-tasiR-CP construct the processing was as predicted 21-nt phased in register with miR173-guided cleavage, the processing of syn-tasiR-3NCR is far from what was expected. A 22-nt species from the miR173-guided cleavage was a guide of two series of phased small RNAs, one of them in an exact 21-nt register, and the other one in a mixed of 21-/22-nt frame. In addition, both constructs produced abundant PPV-derived small RNAs in the absence of miR173 as a consequence of a strong sense post-transcriptional gene silencing induction. The antiviral effect of both constructs was also evaluated in the presence or absence of miR173 and showed that the impairment of PPV infection was not significantly higher when miR173 was present. The results show that syn-tasiRNAs processing depends on construct-specific factors that should be further studied before the so-called MIGS (miRNA-induced gene silencing technology can be used reliably.

  11. Effect of water purification process in radioactive content: analysis on small scale purification plants

    International Nuclear Information System (INIS)

    Lopez del Rio, H.; Quiroga S, J. C.; Davila R, J. I.; Mireles G, F.

    2009-10-01

    Water from small scale purification plants is a low cost alternative for consumers in comparison to the bottled commercial presentations. Because of its low cost per liter, the consumption of this product has increased in recent years, stimulating in turn the installation of purification systems for these small businesses. The purpose of this study was to estimate the efficiency of small scale purification systems located in the cities of Zacatecas and Guadalupe, Zacatecas, to reduce the radioactive content of water. It was measured the total alpha and beta activity in water samples of entry and exit to process, through the liquid scintillation technique. In general it was observed that the process is more efficient in removing alpha that beta activity. The fraction of total alpha activity removed varied between 27 and 100%, while between 0 and 77% of the total beta activity was removed by the analyzed plants. In all cases, the total radioactivity level was lower than the maximum permissible value settled by the official mexican standard for drinking water. (Author)

  12. Purification process of recombinant monoclonal antibodies with mixed mode chromatography.

    Science.gov (United States)

    Maria, Sophie; Joucla, Gilles; Garbay, Bertrand; Dieryck, Wilfrid; Lomenech, Anne-Marie; Santarelli, Xavier; Cabanne, Charlotte

    2015-05-08

    An innovative process to purify mAb from CHO cell culture supernatant was developed. This three-step process involved two mixed mode resins and an anion exchange membrane. We used a human IgG mixture to determine the optimal conditions for each purification step. Thereafter, the whole process was evaluated and improved for the purification of a recombinant mAb produced in the supernatant of CHO cells. Once optimized, yield and purity of 88% and 99.9%, respectively were comparable to those obtained in a conventional process based on a capture step using protein A. In addition, aggregates, HCPs and DNA levels in the purified fraction were below regulatory specifications. Then we used mass spectrometry to identify contaminating proteins in the antibody fraction in order to highlight the behavior of HCPs. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. siMacro: A Fast and Easy Data Processing Tool for Cell-Based Genomewide siRNA Screens

    Directory of Open Access Journals (Sweden)

    Nitin Kumar Singh

    2013-03-01

    Full Text Available Growing numbers of studies employ cell line-based systematic short interfering RNA (siRNA screens to study gene functions and to identify drug targets. As multiple sources of variations that are unique to siRNA screens exist, there is a growing demand for a computational tool that generates normalized values and standardized scores. However, only a few tools have been available so far with limited usability. Here, we present siMacro, a fast and easy-to-use Microsoft Office Excel-based tool with a graphic user interface, designed to process single-condition or two-condition synthetic screen datasets. siMacro normalizes position and batch effects, censors outlier samples, and calculates Z-scores and robust Z-scores, with a spreadsheet output of >120,000 samples in under 1 minute.

  14. Review of desulfurization process for biogas purification

    Science.gov (United States)

    Xiao, Cong; Ma, Yunqian; Ji, Dandan; Zang, Lihua

    2017-12-01

    Hydrogen sulfide (H2S) is a toxic and odorous compound present in biogas produced by the anaerobic digestion of biosolids and other organic materials. Elimination of H2S is necessary as it is extremely hazardous to human health, poisonous to process catalysts and corrosive to equipment. The desulfurization technology is an important part for efficient utilization of biogas. In this paper, the traditional wet and dry desulfurization technology for biogas was reviewed, and the new research progress of biological desulfurization technologies are also introduced.

  15. PROCESS FOR THE PURIFICATION OF URANIUM

    Science.gov (United States)

    Rosenfeld, S.

    1959-01-20

    A proccss is described for reclaiming uranium values from aqueous solutions containing U, Fe, Ni, Cu, and Cr comprising treating the solution with NH/sub 3/ to precipitate the: U, Fc, and Cr and leaving Cu and Ni in solution as ammonia complex ions. The precipitate is chlorinated with CCl/sub 4/ at an elevated temperature to convert the U, Tc, and Cr into their chlorides. The more volatile FeCl/sub 3/ and CrCl/sub 3/ are separated from the UCl/sub 4/. The process is used when U is treated in a calutron, and composite solutions are produccd which contain dissolved products of stainless steel.

  16. Process for the biological purification of waste water

    DEFF Research Database (Denmark)

    1992-01-01

    Process for the biological purification of waste water by the activated sludge method, the waste water being mixed with recirculated sludge and being subjected to an anaerobic treatment, before the waste water thus treated is alternately subjected to anoxic and aerobic treatments and the waste...... water thus treated is led into a clarification zone for settling sludge, which sludge is recirculated in order to be mixed with the crude waste water. As a result, a simultaneous reduction of the content both of nitrogen and phosphorus of the waste water is achieved....

  17. Separation process design for isolation and purification of natural products

    DEFF Research Database (Denmark)

    Malwade, Chandrakant R.

    Natural products are defined as secondary metabolites produced by plants and form a vast pool of compounds with unlimited chemical and functional diversity. Many of these secondary metabolites are high value added chemicals that are frequently used as ingredients in food, cosmetics, pharmaceuticals...... and other consumer products. Therefore, process technology towards industrial scale production of such high value chemicals from plants has significant value. Natural products can be obtained in pure form via synthetic or semi-synthetic route, but due to their complicated nature these methods have not been...... developed to the extent of industrial production for majority of natural products. Thus, isolation and purification of such natural products from plants is the most viable way to obtain natural products in pure form. This PhD project is mainly concerned with the design of separation process to isolate...

  18. Production and processing of siRNA precursor transcripts from the highly repetitive maize genome.

    Directory of Open Access Journals (Sweden)

    Christopher J Hale

    2009-08-01

    Full Text Available Mutations affecting the maintenance of heritable epigenetic states in maize identify multiple RNA-directed DNA methylation (RdDM factors including RMR1, a novel member of a plant-specific clade of Snf2-related proteins. Here we show that RMR1 is necessary for the accumulation of a majority of 24 nt small RNAs, including those derived from Long-Terminal Repeat (LTR retrotransposons, the most common repetitive feature in the maize genome. A genetic analysis of DNA transposon repression indicates that RMR1 acts upstream of the RNA-dependent RNA polymerase, RDR2 (MOP1. Surprisingly, we show that non-polyadenylated transcripts from a sampling of LTR retrotransposons are lost in both rmr1 and rdr2 mutants. In contrast, plants deficient for RNA Polymerase IV (Pol IV function show an increase in polyadenylated LTR RNA transcripts. These findings support a model in which Pol IV functions independently of the small RNA accumulation facilitated by RMR1 and RDR2 and support that a loss of Pol IV leads to RNA Polymerase II-based transcription. Additionally, the lack of changes in general genome homeostasis in rmr1 mutants, despite the global loss of 24 nt small RNAs, challenges the perceived roles of siRNAs in maintaining functional heterochromatin in the genomes of outcrossing grass species.

  19. Denitrification of acid wastes from uranium purification processes

    International Nuclear Information System (INIS)

    Clark, F.E.; Francis, C.W.; Francke, H.C.; Strohecker, J.W.

    1975-11-01

    Laboratory and pilot-plant investigations have shown the technical feasibility of removing nitrates from neutralized acid wastes from uranium purification processes by biological denitrification, a dissimilatory process in which the nitrate ion is reduced to nitrogen gas by specific bacteria. The process requires anaerobic conditions and an organic carbon source, as well as other life-sustaining constituents. These denitrification studies produced process design information on a columnar denitrification plant and on continuous-flow, stirred-bed reactors. Denitrification, using packed columns, was found to be desirable for soluble salts, such as those of sodium and ammonium; denitrification, using stirred reactors, was found to be desirable for mixtures containing insoluble salts, such as those of calcium and aluminum. Packed columns were found to have denitrification rates ranging up to 122 grams of nitrate per day per cubic decimeter of column volume; stirred-bed reactors have been shown to have reaction rates near 10 grams of nitrate per day per cubic decimeter of reactor volume. The continuous-flow, stirred-bed reactors were selected for scaleup studies because of the solids-removal problems associated with packed columns when operating on feeds containing high concentrations of insoluble salts or ions which form insoluble salts with the products of the denitrification reaction

  20. The application of modified montmorillonite in the processes of baromembrane purification of water from U (VI)

    International Nuclear Information System (INIS)

    Yurlova, L.Yu.; Krivoruchko, A.P.

    2010-01-01

    The processes of uranium-containing water purification by ultra- and nanofiltration methods combined with the use of montmorillonite modified by polyethyleneimine are studied. It is shown that the application of montmorillonite allows one to obtain the high indices of the uranium-containing water purification by baromembrane methods.

  1. Pathway-based analysis of genome-wide siRNA screens reveals the regulatory landscape of APP processing.

    Directory of Open Access Journals (Sweden)

    Luiz Miguel Camargo

    Full Text Available The progressive aggregation of Amyloid-β (Aβ in the brain is a major trait of Alzheimer's Disease (AD. Aβ is produced as a result of proteolytic processing of the β-amyloid precursor protein (APP. Processing of APP is mediated by multiple enzymes, resulting in the production of distinct peptide products: the non-amyloidogenic peptide sAPPα and the amyloidogenic peptides sAPPβ, Aβ40, and Aβ42. Using a pathway-based approach, we analyzed a large-scale siRNA screen that measured the production of different APP proteolytic products. Our analysis identified many of the biological processes/pathways that are known to regulate APP processing and have been implicated in AD pathogenesis, as well as revealing novel regulatory mechanisms. Furthermore, we also demonstrate that some of these processes differentially regulate APP processing, with some mechanisms favouring production of certain peptide species over others. For example, synaptic transmission having a bias towards regulating Aβ40 production over Aβ42 as well as processes involved in insulin and pancreatic biology having a bias for sAPPβ production over sAPPα. In addition, some of the pathways identified as regulators of APP processing contain genes (CLU, BIN1, CR1, PICALM, TREM2, SORL1, MEF2C, DSG2, EPH1A recently implicated with AD through genome wide association studies (GWAS and associated meta-analysis. In addition, we provide supporting evidence and a deeper mechanistic understanding of the role of diabetes in AD. The identification of these processes/pathways, their differential impact on APP processing, and their relationships to each other, provide a comprehensive systems biology view of the "regulatory landscape" of APP.

  2. Purification and detoxification of petroleum refinery wastewater by electrocoagulation process.

    Science.gov (United States)

    Gousmi, N; Sahmi, A; Li, H Z; Poncin, S; Djebbar, R; Bensadok, K

    2016-09-01

    The treatment of synthetic oily wastewater having the characteristics of a typical petroleum refinery wastewater (PRW) by electrocoagulation (EC) using iron and aluminum electrodes was conducted in an electrolytic reactor equipped with fluid recirculation. During the treatment, the emulsion stability was followed by the measurement of Zeta potential and particle sizes. Effects of some operating conditions such as electrodes material, current density and electrolysis time on removal efficiencies of turbidity, and chemical oxygen demand (COD) were investigated in detail. The PRW purification by the EC process was found to be the most effective using aluminum as the anode and cathode, current density of 60 A/m(2) and 30 min of electrolysis time. Under these conditions, the process efficiencies were 83.52% and 99.94%, respectively, for COD and turbidity removals which correspond to final values of 96 mg O2/L and 0.5 NTU. A moderate energy consumption (0.341 kWh) was needed to treat 1 m(3) of PRW. Besides, the ecotoxicity test proved that toxic substances presented in the PRW, and those inhibiting the germination growth of whet, were eliminated by the EC technique.

  3. Plasma processes including electron beam for off-gases purification

    International Nuclear Information System (INIS)

    Chmielewski, A.G.; Witman, S.; Licki, J.

    2011-01-01

    Complete text of publication follows. Non-thermal plasma technologies based on different methods of plasma generation are being applied for ozone generation for different applications, waste water and off-gases treatment. Plasmas create reactive species, in particular ions, radicals or other reactive compounds, which can decompose pollutant molecules, organic particulate matter or soot. Electron beam flue gas treatment is another plasma-based technology which has been successfully demonstrated on industrial scale coal fired power plants. High efficiency of SO 2 (> 95%) and NO x (> 70%) has been obtained and industrial plant applying this process has been built in Poland. The further investigations carried out all over the world have illustrated that the process can be applied for poly-aromatic hydrocarbons (PAH) destruction as well, and just recently research laboratories in the US and South Korea have reported in the feasibility of the process for mercury removal from the flue gas. The recent studies concern a new type of accelerators implementation in the industrial scale, application of the process in the high sulfur oil fired boilers and Diesel off - gases purification. The treatment of the flue gases with the high NOx concentration is a special challenge for the technology since the main energy consumption (and applied accelerators power) is related to this pollutant content in the processed off gases. The pulse beams and scavenger application can be a solution to reduce investment and operational costs. The further development of the technology is directly connected with high power accelerators development. Acknowledgement: The R and D activities are supported by the European Regional Development Found in the frame of the project PlasTEP 'Dissemination and fostering of plasma based technological innovation for environment protection in the Baltic Sea Region'.

  4. Process for recovery and purification of lithium from dilute sources

    International Nuclear Information System (INIS)

    Kunugita, Eiichi; Kim, Jong-Hwa; Komasawa, Isao

    1990-01-01

    A process was studied for recovery and purification of lithium from hot spring water and leachate of coal fly ash in which lithium is present at very low concentration in a mixture of high concentration of less desirable species such as alkali metals, alkaline earth metals and others. Lithium is, as a first step, adsorbed selectively by an ion-sieve type adsorbent, λ-MnO 2 , which can effect separation by adsorbing lithium alone in its intraparticle spaces while adsorbing most metals on its surface. Stagewise elutions are performed, employing two elutrients: NH 4 NO 3 and then HNO 3 solution. The concentration ratio of lithium and sodium is 1/70∼1/120 in the original feed stream, and this is upgraded to 300/1 in the pregnant elutrient. Some impurities in the pregnant elutrient is removed by a solvent extraction technique, employing a mixed extractant of a β-diketone (LIX51) and tri-n-octyl-phosphine oxide in kerosene. A lithium solution with an undetectable amount of impurities is obtained by single extraction followed by single scrubbing with dilute hydrochloric acid of carefully controlled concentration. (author)

  5. Development of solvent extraction process for erbium purification

    International Nuclear Information System (INIS)

    Singh, D.K.; Anitha, M.; Vijayalakshmi, R.; Chakravartty, J.K.

    2016-01-01

    Erbium an important heavy rare earth (HRE) finds valuable application in space and nuclear energy technology. High purity erbium oxide is used as coating material for test blanket module of fusion reactor to prevent the tritium permeation. The total concentration of HRE (including Er) in only proven resource of rare earths in Indian monazite mineral is < 0.05%. Its separation from such a low concentration and also from host of other chemically similar elements like Y, Dy, Ho, Yb, Tm etc is quite difficult and challenging. A solvent extraction process employing PC88A and Aliquat336 has been developed for the purification of erbium oxide from two types of HRE fractions having % composition; (i) Y 2 O 3 : 0.18, Tb 4 O 7 : 0.28, Dy 2 CO 2 : 47.07, Er 2 O 3 : 35.03, HO 2 O 3 : 10.11, Yb 2 O 3 : 5.88, Tm 2 O 3 : 1.43 and (ii) Dy 2 O 3 : 6.39, Er 2 O 3 : 49.43, HO 2 O 3 : 10.43, Tm 2 O 3 : 2.7, Y 2 O 3 : 24.08, Yb 2 O 3 : 6.96. PC88A was used to process low Y content concentrate from chloride medium whereas Aliquat336 was found to be suitable in thiocynate medium to treat the concentrate with high Y content. Effects of process variables such as acidity, extractant concentration, total oxide concentration in feed, number of stages, phase ratio, scrubbing agent were investigated for both the systems

  6. Relationship between the losses of furfural in the oil purification process and the furfural quality

    Energy Technology Data Exchange (ETDEWEB)

    Shiriaeva, G.P.; Baiburskaia, E.L.; Kalenik, G.S.; Martynenko, A.G.; Okhrimenko, N.V.

    1981-01-01

    It is demonstrated that the use of low quality furfural in the purification process of oil results in a situation where approximately 10% of the solvent delivered to these enterprises make up the avoidable losses.

  7. Optimization of mass flow rate in RGTT200K coolant purification for Carbon Monoxide conversion process

    International Nuclear Information System (INIS)

    Sumijanto; Sriyono

    2016-01-01

    Carbon monoxide is a species that is difficult to be separated from the reactor coolant helium because it has a relatively small molecular size. So it needs a process of conversion from carbon monoxide to carbondioxide. The rate of conversion of carbon monoxide in the purification system is influenced by several parameters including concentration, temperature and mass flow rate. In this research, optimization of the mass flow rate in coolant purification of RGTT200K for carbon monoxide conversion process was done. Optimization is carried out by using software Super Pro Designer. The rate of reduction of reactant species, the growth rate between the species and the species products in the conversion reactions equilibrium were analyzed to derive the mass flow rate optimization of purification for carbon monoxide conversion process. The purpose of this study is to find the mass flow rate of purification for the preparation of the basic design of the RGTT200K coolant helium purification system. The analysis showed that the helium mass flow rate of 0.6 kg/second resulted in an un optimal conversion process. The optimal conversion process was reached at a mass flow rate of 1.2 kg/second. A flow rate of 3.6 kg/second – 12 kg/second resulted in an ineffective process. For supporting the basic design of the RGTT200K helium purification system, the mass flow rate for carbon monoxide conversion process is suggested to be 1.2 kg/second. (author)

  8. Modelling a water purification process for quality monitoring

    NARCIS (Netherlands)

    Meulen, van der F.H.; Luca, S.; Overal, G.; Dubbeldam, J.L.A.; Di Bucchianico, A.; Jongbloed, G.; Dubbeldam, J.; Groenevelt, W.; Heemink, A.W.; Lahaye, D.; Meerman, C.; Meulen, van der F.

    2014-01-01

    This paper deals with a quality engineering problem introduced by ‘Waterlaboratorium Noord’ (WLN) situated at the Netherlands. In-terest lies in determining an optimal sampling frequency that provides suÿcient information on the water quality in a drinking water purifica-tion plant. The water

  9. Research progress of novel adsorption processes in water purification:A review

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    As an effective, efficient, and economic approach for water purification, adsorbents and adsorption processes have been widely studied and applied in different aspects for a long time. In the recent years, a lot of novel adsorption processes have been developed for enhancing the efficiency of removing the organic and inorganic contaminants from water. This article reviews some new adsorbents and advanced adsorption methods that specialize in their compositions, structures, functions, and characteristics used in water treatment. The review emphasizes adsorption/catalytic oxidation process, adsorption/catalytic reduction process, adsorption coupled with redox process, biomimetic sorbent and its sorption behaviors of POPs, and modified adsorbents and their water purification efficiency.

  10. Decisional tool to assess current and future process robustness in an antibody purification facility.

    Science.gov (United States)

    Stonier, Adam; Simaria, Ana Sofia; Smith, Martin; Farid, Suzanne S

    2012-07-01

    Increases in cell culture titers in existing facilities have prompted efforts to identify strategies that alleviate purification bottlenecks while controlling costs. This article describes the application of a database-driven dynamic simulation tool to identify optimal purification sizing strategies and visualize their robustness to future titer increases. The tool harnessed the benefits of MySQL to capture the process, business, and risk features of multiple purification options and better manage the large datasets required for uncertainty analysis and optimization. The database was linked to a discrete-event simulation engine so as to model the dynamic features of biopharmaceutical manufacture and impact of resource constraints. For a given titer, the tool performed brute force optimization so as to identify optimal purification sizing strategies that minimized the batch material cost while maintaining the schedule. The tool was applied to industrial case studies based on a platform monoclonal antibody purification process in a multisuite clinical scale manufacturing facility. The case studies assessed the robustness of optimal strategies to batch-to-batch titer variability and extended this to assess the long-term fit of the platform process as titers increase from 1 to 10 g/L, given a range of equipment sizes available to enable scale intensification efforts. Novel visualization plots consisting of multiple Pareto frontiers with tie-lines connecting the position of optimal configurations over a given titer range were constructed. These enabled rapid identification of robust purification configurations given titer fluctuations and the facility limit that the purification suites could handle in terms of the maximum titer and hence harvest load. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

  11. Materials measurement and accounting in an operating plutonium conversion and purification process. Phase I. Process modeling and simulation

    International Nuclear Information System (INIS)

    Thomas, C.C. Jr.; Ostenak, C.A.; Gutmacher, R.G.; Dayem, H.A.; Kern, E.A.

    1981-04-01

    A model of an operating conversion and purification process for the production of reactor-grade plutonium dioxide was developed as the first component in the design and evaluation of a nuclear materials measurement and accountability system. The model accurately simulates process operation and can be used to identify process problems and to predict the effect of process modifications

  12. [Alcohol-purification technology and its particle sedimentation process in manufactory of Fufang Kushen injection].

    Science.gov (United States)

    Liu, Xiaoqian; Tong, Yan; Wang, Jinyu; Wang, Ruizhen; Zhang, Yanxia; Wang, Zhimin

    2011-11-01

    Fufang Kushen injection was selected as the model drug, to optimize its alcohol-purification process and understand the characteristics of particle sedimentation process, and to investigate the feasibility of using process analytical technology (PAT) on traditional Chinese medicine (TCM) manufacturing. Total alkaloids (calculated by matrine, oxymatrine, sophoridine and oxysophoridine) and macrozamin were selected as quality evaluation markers to optimize the process of Fufang Kushen injection purification with alcohol. Process parameters of particulate formed in the alcohol-purification, such as the number, density and sedimentation velocity, were also determined to define the sedimentation time and well understand the process. The purification process was optimized as that alcohol is added to the concentrated extract solution (drug material) to certain concentration for 2 times and deposited the alcohol-solution containing drug-material to sediment for some time, i.e. 60% alcohol deposited for 36 hours, filter and then 80% -90% alcohol deposited for 6 hours in turn. The content of total alkaloids was decreased a little during the depositing process. The average settling time of particles with the diameters of 10, 25 microm were 157.7, 25.2 h in the first alcohol-purified process, and 84.2, 13.5 h in the second alcohol-purified process, respectively. The optimized alcohol-purification process remains the marker compositions better and compared with the initial process, it's time saving and much economy. The manufacturing quality of TCM-injection can be controlled by process. PAT pattern must be designed under the well understanding of process of TCM production.

  13. Contribution to the study of new hydrogen production, purification and storage processes

    International Nuclear Information System (INIS)

    Manaud, Jean-Pierre

    1984-01-01

    This research thesis addresses the various aspects of hydrogen production, purification and process within the scope of hydrogen-based energy production. Hydrogen production is achieved by water decomposition through a thermo-chemical process. The author reports the thermodynamic assessment of a water decomposition thermo-chemical cycle for chlorine and sulphur-related cycles. He reports the experimental investigation of hydrogen purification by selective diffusion, the study of contamination of a CeMg12 alloy by nitrogen, oxygen and water vapour with application to hydrogen storage under the form of hydrides [fr

  14. A purification process for an inert gas system

    International Nuclear Information System (INIS)

    Raj, S.S.; Samanta, S.K.; Jain, N.G.; Deshingkar, D.S.; Ramaswamy, M.

    1984-01-01

    Special inert atmosphere is desired inside hot cells used for handling radioactive materials. In this report, details of experiments conducted to generate data required for the design of a system for maintaining very low levels of organic and acid vapours, oxygen and moisture in a nitrogen gas inert atmosphere, are described. Several grades of activated charcoals impregnated with 1% KOH were studied for the adsorption of acidic and organic vapours. A Pd/Al 2 O 3 catalyst was developed to remove oxygen with greater than 90% efficiency. For the removal of moisture, a regenerable molecular sieve 4A dual-bed was provided. Based on the performance data thus generated, an integrated purification system for nitrogen gas is proposed. (author)

  15. Application of hydrometallurgy techniques in quartz processing and purification: a review

    Science.gov (United States)

    Lin, Min; Lei, Shaomin; Pei, Zhenyu; Liu, Yuanyuan; Xia, Zhangjie; Xie, Feixiang

    2018-04-01

    Although there have been numerous studies on separation and purification of metallic minerals by hydrometallurgy techniques, applications of the chemical techniques in separation and purification of non-metallic minerals are rarely reported. This paper reviews disparate areas of study into processing and purification of quartz (typical non-metallic ore) in an attempt to summarize current work, as well as to suggest potential for future consolidation in the field. The review encompasses chemical techniques of the quartz processing including situations, progresses, leaching mechanism, scopes of application, advantages and drawbacks of micro-bioleaching, high temperature leaching, high temperature pressure leaching and catalyzed high temperature pressure leaching. Traditional leaching techniques including micro-bioleaching and high temperature leaching are unequal to demand of modern glass industry for quality of quartz concentrate because the quartz products has to be further processed. High temperature pressure leaching and catalyzed high temperature pressure leaching provide new ways to produce high-grade quartz sand with only one process and lower acid consumption. Furthermore, the catalyzed high temperature pressure leaching realizes effective purification of quartz with extremely low acid consumption (no using HF or any fluoride). It is proposed that, by integrating the different chemical processes of quartz processing and expounding leaching mechanisms and scopes of application, the research field as a monopolized industry would benefit.

  16. Purification process of uranium hexafluoride containing traces of plutonium fluoride and/or neptunium fluoride

    International Nuclear Information System (INIS)

    Aubert, J.; Bethuel, L.; Carles, M.

    1983-01-01

    In this process impure uranium hexafluoride is contacted with a metallic fluoride chosen in the group containing lead fluoride PbF 2 , uranium fluorides UFsub(4+x) (0 3 at a temperature such as plutonium and/or neptunium are reduced and pure uranium hexafluoride is recovered. Application is made to uranium hexafluoride purification in spent fuel reprocessing [fr

  17. The importance of the ammonia purification process in ammonia-water absorption systems

    International Nuclear Information System (INIS)

    Fernandez-Seara, Jose; Sieres, Jaime

    2006-01-01

    Practical experience in working with ammonia-water absorption systems shows that the ammonia purification process is a crucial issue in order to obtain an efficient and reliable system. In this paper, the detrimental effects of the residual water content in the vapour refrigerant are described and quantified based on the system design variables that determine the effectiveness of the purification process. The study has been performed considering a single stage system with a distillation column with complete condensation. The ammonia purification effectiveness of the column is analysed in terms of the efficiencies in the stripping and rectifying sections and the reflux ratio. By varying the efficiencies from 0 to 1, systems with neither the rectifying nor stripping section, with either the rectifying or stripping section, or with both sections can be considered. The impact of the ammonia purification process on the absorption system performance is studied based on the column efficiencies and reflux ratio; and its effects on refrigerant concentration, system COP, system pressures and main system mass flow rates and concentrations are analysed. When the highest efficiency rectifying sections are used a combination of generation temperature and reflux ratio which leads to optimum COP values is found. The analysis covers different operating conditions with air and water cooled systems from refrigeration to air conditioning applications by changing the evaporation temperature. The importance of rectification in each kind of application is evaluated

  18. Function and anatomy of plant siRNA pools derived from hairpin transgenes

    Directory of Open Access Journals (Sweden)

    Lee Kevin AW

    2007-11-01

    Full Text Available Abstract Background RNA interference results in specific gene silencing by small-interfering RNAs (siRNAs. Synthetic siRNAs provide a powerful tool for manipulating gene expression but high cost suggests that novel siRNA production methods are desirable. Strong evolutionary conservation of siRNA structure suggested that siRNAs will retain cross-species function and that transgenic plants expressing heterologous siRNAs might serve as useful siRNA bioreactors. Here we report a detailed evaluation of the above proposition and present evidence regarding structural features of siRNAs extracted from plants. Results Testing the gene silencing capacity of plant-derived siRNAs in mammalian cells proved to be very challenging and required partial siRNA purification and design of a highly sensitive assay. Using the above assay we found that plant-derived siRNAs are ineffective for gene silencing in mammalian cells. Plant-derived siRNAs are almost exclusively double-stranded and most likely comprise a mixture of bona fide siRNAs and aberrant partially complementary duplexes. We also provide indirect evidence that plant-derived siRNAs may contain a hitherto undetected physiological modification, distinct from 3' terminal 2-O-methylation. Conclusion siRNAs produced from plant hairpin transgenes and extracted from plants are ineffective for gene silencing in mammalian cells. Thus our findings establish that a previous claim that transgenic plants offer a cost-effective, scalable and sustainable source of siRNAs is unwarranted. Our results also indicate that the presence of aberrant siRNA duplexes and possibly a plant-specific siRNA modification, compromises the gene silencing capacity of plant-derived siRNAs in mammalian cells.

  19. Thermal Stability of siRNA Modulates Aptamer- conjugated siRNA Inhibition

    Directory of Open Access Journals (Sweden)

    Alexey Berezhnoy

    2012-01-01

    Full Text Available Oligonucleotide aptamer-mediated in vivo cell targeting of small interfering RNAs (siRNAs is emerging as a useful approach to enhance the efficacy and reduce the adverse effects resulting from siRNA-mediated genetic interference. A current main impediment in aptamer-mediated siRNA targeting is that the activity of the siRNA is often compromised when conjugated to an aptamer, often requiring labor intensive and time consuming design and testing of multiple configurations to identify a conjugate in which the siRNA activity has not been significantly reduced. Here, we show that the thermal stability of the siRNA is an important parameter of siRNA activity in its conjugated form, and that siRNAs with lower melting temperature (Tm are not or are minimally affected when conjugated to the 3′ end of 2′F-pyrimidine-modified aptamers. In addition, the configuration of the aptamer-siRNA conjugate retains activity comparable with the free siRNA duplex when the passenger strand is co-transcribed with the aptamer and 3′ overhangs on the passenger strand are removed. The approach described in this paper significantly reduces the time and effort necessary to screening siRNA sequences that retain biological activity upon aptamer conjugation, facilitating the process of identifying candidate aptamer-siRNA conjugates suitable for in vivo testing.

  20. Evaluation of the efficiency of the processes of purification of antimony to semiconductor grade purity

    International Nuclear Information System (INIS)

    Walis, L.; Rowinska, L.; Panczyk, E.

    1992-01-01

    A complex of techniques for purification of antimony from arsenic has been examined with the aid of radiotracer 76 As. The investigated processes comprised vacuum distillation, zone melting and remelting of the metal under artificial slags. The purification efficiencies for the above processes were high and amounted to 94% (for 30% of the charge), 50% (for 50% of the charge) and 99.5% (for 60% of the charge), respectively. Attempts were made to determine the kinetics of the separation of arsenic from antimony by distillation. The application of the radioactive tracer made it possible to determine rapidly the distribution of impurities after each stage of the process within a wide concentration range (10 -2 -10 -7 g/g). (author). 7 refs, 4 figs, 6 tabs

  1. Correction in the efficiency of uranium purification process by solvent extraction

    International Nuclear Information System (INIS)

    Franca Junior, J.M.

    1981-01-01

    An uranium solvent extraction, of high purification, with full advantage of absorbed uranium in the begining of process, is described. Including a pulsed column, called correction column, the efficiency of whole process is increased, dispensing the recycling of uranium losses from leaching column. With the correction column the uranium losses go in continuity, for reextraction column, increasing the efficiency of process. The purified uranium is removed in the reextraction column in aqueous phase. The correction process can be carried out with full efficiency using pulsed columns or chemical mixer-settlers. (M.C.K.) [pt

  2. Purification of Contaminated MIL-PRF-83282 Hydraulic Fluid Using the Pall Purifier and Multiple Process Configurations (Preprint)

    National Research Council Canada - National Science Library

    Snyder, Jr., Carl E; Gschwender, Lois J; Gunderson, Stephen L; Fultz, George W

    2006-01-01

    .... This report describes a project that evaluated the effectiveness of various hydraulic fluid purification process configurations on the removal of water and particulate contaminants from MIL-PRF-83282...

  3. Extraction and partial purification of chitinase from mycosymbiont and its relation with mycorrhiza association process

    International Nuclear Information System (INIS)

    Darusman, L.K.; Purwakusumah, E.D.; Nurlia, N.

    1999-01-01

    Extraction effectivity and partial purification of chitinase extracellular metabolite from Scleroderma columnare, Pisolithus tinctorius, Trichoderma harzianum and the root of Shorea selanica have been searched. S. columnare and P. tinctorius were the mycosymbiont for S. selanica while T. harzianum was not. (NH4)2SO4 was the very effective solvent for crude extracellular enzyme extraction, followed by PEG-6000 and ethanol 50 percent respectively. The activity of P. tinctorius was the lowest among the microbe while S. columnare was the highest. The activity lowered by purification process but specific activity was not. The chitinase activity of inoculated root was higher in the S. columnare association than P. tinctorius's also the percentage of root chitin content and infection rate. It mean that S. columnare more effective as mycosymbiont. The periods of association lowered the activity of root chitinase but this phenomenon did not happen in the root of S. selanica with T. harzianum infection

  4. A Simulation of Pre-Arcing Plasma Discharge Processes in Water Purification

    International Nuclear Information System (INIS)

    Rodriguez-Mendez, B. G.; Piedad-Beneitez, A. de la; Lopez-Callejas, R.; Godoy-Cabrera, O. G.; Benitez-Read, J. S.; Pacheco-Sotelo, J. O.; Pena-Eguiluz, R.; Mercado-Cabrera, A.; Valencia-A, R.; Barocio, S. R.

    2006-01-01

    The simulation of a water purification system within a coaxial cylinder reactor operated by 1 kHz frequency plasma discharges in pre-arcing regimes is presented. In contrast with precedent works, this computational model considers three mechanisms of the system operation: (a) the relevant physical characteristics of water (b) the ionisation and expansion processes in the spark channel including the near-breakdown electric current generated by the rate of change of the effective capacitance and resistance in the discharge, and (c) the energy associated with this initial spark in the water. The outcome of the model seems to meet all main requirements to allow the design and construction of specific water purification technology devices

  5. Catalyst study for the plasma exhaust purification process

    International Nuclear Information System (INIS)

    Chabot, J.; Sannier, J.

    1990-01-01

    Several catalysts available from commercial sources have been screened to find out specific catalysts which allow complete methane oxidation and ammonia decomposition at temperature as low as possible in order to minimize tritium loss by permeation through processing equipment walls. Afterwards, an extended kinetic investigation has been performed on the best catalysts to achieve the data necessary to unit calculations. For methane oxidation, a palladium on alumina catalyst shows a very satisfactory low-temperature efficiency while a non-precious metal catalyst made of nickel oxide and alumina was found to be the more efficient for ammonia decomposition

  6. Application of dielectric constant measurement in microwave sludge disintegration and wastewater purification processes.

    Science.gov (United States)

    Kovács, Petra Veszelovszki; Lemmer, Balázs; Keszthelyi-Szabó, Gábor; Hodúr, Cecilia; Beszédes, Sándor

    2018-05-01

    It has been numerously verified that microwave radiation could be advantageous as a pre-treatment for enhanced disintegration of sludge. Very few data related to the dielectric parameters of wastewater of different origins are available; therefore, the objective of our work was to measure the dielectric constant of municipal and meat industrial wastewater during a continuous flow operating microwave process. Determination of the dielectric constant and its change during wastewater and sludge processing make it possible to decide on the applicability of dielectric measurements for detecting the organic matter removal efficiency of wastewater purification process or disintegration degree of sludge. With the measurement of dielectric constant as a function of temperature, total solids (TS) content and microwave specific process parameters regression models were developed. Our results verified that in the case of municipal wastewater sludge, the TS content has a significant effect on the dielectric constant and disintegration degree (DD), as does the temperature. The dielectric constant has a decreasing tendency with increasing temperature for wastewater sludge of low TS content, but an adverse effect was found for samples with high TS and organic matter contents. DD of meat processing wastewater sludge was influenced significantly by the volumetric flow rate and power level, as process parameters of continuously flow microwave pre-treatments. It can be concluded that the disintegration process of food industry sludge can be detected by dielectric constant measurements. From technical purposes the applicability of dielectric measurements was tested in the purification process of municipal wastewater, as well. Determination of dielectric behaviour was a sensitive method to detect the purification degree of municipal wastewater.

  7. PROCESS FOR THE RECOVERY AND PURIFICATION OF URANIUM DEPOSITS

    Science.gov (United States)

    Carter, J.M.; Kamen, M.D.

    1958-10-14

    A process is presented for recovering uranium values from UCl/sub 4/ deposits formed on calutrons. Such deposits are removed from the calutron parts by an aqueous wash solution which then contains the uranium values in addition to the following impurities: Ni, Cu, Fe, and Cr. This impurity bearing wash solution is treated with an oxidizing agent, and the oxidized solution is then treated with ammonia in order to precipitate the uranium as ammonium diuranate. The metal impurities of iron and chromium, which form insoluble hydroxides, are precipitated along with the uranium values. The precipitate is separated from the solution, dissolved in acid, and the solution again treated with ammonia and ammonium carbonate, which results in the precipitation of the metal impurities as hydroxides while the uranium values remain in solution.

  8. Industrial compatible re-growth of vertically aligned multiwall carbon nanotubes by ultrafast pure oxygen purification process

    DEFF Research Database (Denmark)

    Bu, Ian Y.Y.; Hou, Kai; Engstrøm, Daniel Southcott

    2011-01-01

    amorphous carbon and reactivate nickel catalyst. Controlling of the purification temperature is important for high yield CNTs, as excessive high annealing temperature results in deformation of the CNTs. Unlike hazardous wet purification treatments, purified CNTs remained vertically aligned and offer......Reproducible high-yield purification process of multiwalled carbon nanotubes (CNTs) was developed by thermal annealing in ultrapure oxygen. The optimized condition involves thermal annealing via a PID controlled heater in high purity oxygen at temperature of 450°C for 180s, which burns out...

  9. Plasma exhaust purification: Experimental basis for a process concept

    International Nuclear Information System (INIS)

    Penzhorn, R.D.; Gunther, K.; Nolte, K.

    1987-01-01

    At KfK a process for the recovery of D,T from a noble gas stream containing up to 16 mol % of tritiated (Q/sub 2/, Q/sub 2/O, NQ/sub 3/, CQ/sub 4/ with Q = D,T) and non-tritiated impurities (He, Ar, O/sub 2/, CO, CO/sub 2/, etc) is presently under investigation. In a first step CO is oxidized to CO/sub 2/ over a hopcalite bed at 120 0 C. Next, molecular oxygen and oxygen from water are gettered on a U bed at 250 - 300 0 C. The gases are then send through a Pd/Ag diffuser, where NQ/sub 3/ is decomposed quantitatively into N/sub 2/ and Q/sub 2/, the latter permeating out of the loop together with residual molecular Q/sub 2/ originally present in the noble gas stream. Finally, the gaseous mixture, now consisting of He, AR, CO/sub 2/, N/sub 2/ and CQ/sub 4/, is passed over a Ni/Al/sub 2/O/sub 3/ catalyst held at 450 - 500 0 C. On this catalyst CQ/sub 4/ is decomposed into the elements, the reaction becoming quantitative (DF/sub CQ/4/sub / > 1.3 x 10/sup 6/) if the produced hydrogen is continuously removed from the loop via the Pd/Ag diffuser

  10. Purification process of natural graphite as anode for Li-ion batteries: chemical versus thermal

    Science.gov (United States)

    Zaghib, K.; Song, X.; Guerfi, A.; Rioux, R.; Kinoshita, K.

    The intercalation of Li ions in natural graphite that was purified by chemical and thermal processes was investigated. A new chemical process was developed that involved a mixed aqueous solution containing 30% H 2SO 4 and 30% NH xF y heated to 90 °C. The results of this process are compared to those obtained by heating the natural graphite from 1500 to 2400 °C in an inert environment (thermal process). The first-cycle coulombic efficiency of the purified natural graphite obtained by the chemical process is 91 and 84% after the thermal process at 2400 °C. Grinding the natural graphite before or after purification had no significant effect on electrochemical performance at low currents. However, grinding to a very small particle size before purification permitted optimization of the size distribution of the particles, which gives rise to a more homogenous electrode. The impurities in the graphite play a role as microabrasion agents during grinding which enhances its hardness and improves its mechanical properties. Grinding also modifies the particle morphology from a 2- to a 3-D structure (similar in shape to a potato). This potato-shaped natural graphite shows high reversible capacity at high current densities (about 90% at 1 C rate). Our analysis suggests that thermal processing is considerably more expensive than the chemical process to obtain purified natural graphite.

  11. Production of Cyclin D1 specific siRNAs by double strand processing for gene therapy of esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Negar Mottaghi-Dastjerdi

    2013-02-01

    Conclusion: dsRNA digestion method includes several steps which the product of each step is used as the precursor for the next step. So optimization and increasing the specificity and product yield should be in the most important goals of the study, because the yield of each step has a direct relationship with the final product yield which is siRNA. Optimizing and increasing the yield, dsRNA digestion method could be a rapid, available and profitable method for siRNA generation, providing large amounts of siRNA.

  12. A flow-through chromatography process for influenza A and B virus purification.

    Science.gov (United States)

    Weigel, Thomas; Solomaier, Thomas; Peuker, Alessa; Pathapati, Trinath; Wolff, Michael W; Reichl, Udo

    2014-10-01

    Vaccination is still the most efficient measure to protect against influenza virus infections. Besides the seasonal wave of influenza, pandemic outbreaks of bird or swine flu represent a high threat to human population. With the establishment of cell culture-based processes, there is a growing demand for robust, economic and efficient downstream processes for influenza virus purification. This study focused on the development of an economic flow-through chromatographic process avoiding virus strain sensitive capture steps. Therefore, a three-step process consisting of anion exchange chromatography (AEC), Benzonase(®) treatment, and size exclusion chromatography with a ligand-activated core (LCC) was established, and tested for purification of two influenza A virus strains and one influenza B virus strain. The process resulted in high virus yields (≥68%) with protein contamination levels fulfilling requirements of the European Pharmacopeia for production of influenza vaccines for human use. DNA was depleted by ≥98.7% for all strains. The measured DNA concentrations per dose were close to the required limits of 10ng DNA per dose set by the European Pharmacopeia. In addition, the added Benzonase(®) could be successfully removed from the product fraction. Overall, the presented downstream process could potentially represent a simple, robust and economic platform technology for production of cell culture-derived influenza vaccines. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Effect of synthetic iron colloids on the microbiological NH(4)(+) removal process during groundwater purification.

    Science.gov (United States)

    Wolthoorn, Anke; Temminghoff, Erwin J M; van Riemsdijk, Willem H

    2004-04-01

    Subsurface aeration is used to oxidise Fe in situ in groundwater that is used to make drinking water potable. In a groundwater system with pH>7 subsurface aeration results in non-mobile Fe precipitate and mobile Fe colloids. Since originally the goal of subsurface aeration is to remove iron in situ, the formation of non-mobile iron precipitate, which facilitates the metal's removal, is the desired result. In addition to this intended effect, subsurface aeration may also strongly enhance the microbiological removal of ammonium (NH(4)(+)) in the purification station. Mobile iron colloids could be the link between subsurface aeration and the positive effect on the NH(4)(+) removal process. Therefore, the objective of this study was to assess whether synthetic iron colloids could improve the NH(4)(+) removal process. The effect of synthetic iron colloids on the NH(4)(+) removal process was studied using an artificial purification set-up on a laboratory scale. Columns that purified groundwater with or without added synthetic iron colloids were set up in duplicate. The results showed that the NH(4)(+) removal was significantly ( alpha = 0.05 ) increased in columns treated with the synthetic iron colloids. Cumulative after 4 months about 10% more NH(4)(+) was nitrified in the columns that was treated with the groundwater containing synthetic iron colloids. The results support the hypothesis that mobile iron colloids could be the link between subsurface aeration and the positive effect on the NH(4)(+) removal process.

  14. DYNAMIC MODELLING AND ADVANCED PREDICTIVE CONTROL OF A CONTINUOUS PROCESS OF ENZYME PURIFICATION

    Directory of Open Access Journals (Sweden)

    Dechechi E.C.

    1997-01-01

    Full Text Available A dynamic mathematical model, simulation and computer control of a Continuous Affinity Recycle Extraction (CARE process, a protein purification technique based on protein adsorption on solid-phase adsorbents is described in this work. This process, consisting of three reactors, is a multivariable process with considerable time delay in the on-line analyses of the controlled variable. An advanced predictive control configuration, specifically the Dynamic Matrix Control (DMC, was applied. The DMC algorithm was applied in process schemes where the aim was to maintain constant the enzyme concentration in the outlet of the third reactor. The performance of the DMC controller was analyzed in the feed-flow disturbances and the results are presented.

  15. Research and Development of Crystal Purification for Product of Uranium Crystallization Process

    Energy Technology Data Exchange (ETDEWEB)

    Yano, K. [Japan Atomic Energy Agency - JAEA (Japan)

    2009-06-15

    Uranium crystallization has been developed as a part of advanced aqueous reprocessing for FBR spent fuel. Although the purity of uranyl nitrate hexahydrate (UNH) crystal from the crystallization process is supposed to meet a specification of FBR blanket fuel, an improvement of its purity is able to reduce the cost of fuel fabrication and storage (in case interim storage of recovered uranium is required). In this work, UNH crystal purification was developed as additional process after crystallization. Contamination of the crystal is caused by mother solution and solid state impurities. They are inseparable by washing and filtration. Mother solution on the surface of UNH crystals is removable by washing, but it is difficult to remove that in an obstructed part of crystalline aggregate by washing. Major elements of solid state impurities are cesium and barium. Cesium precipitates with tetravalent plutonium as a double nitrate, Cs{sub 2}Pu(NO{sub 3}){sub 6}. Barium crystallizes as Ba(NO{sub 3}){sub 2} because of its low solubility in nitric acid solution. It is difficult to separate their particle from UNH crystal by solid-liquid separation such as simple filtration. As a kind of crystal purification, there are some methods using sweating. Sweating is a phenomenon that a crystal melts partly below its melting point and it is caused by depression of freezing point due to impurity. It is considerably applicable for removal of mother solution. Concerning the solid state impurities, which has higher melting point than that of UNH crystal, it is supposed that they are separable by melting UNH crystal and filtration. The behaviors of impurities and applicability of sweating and melting-filtration operations to the purification for UNH crystal were investigated experimentally on a beaker and an engineering scale. With regard to behaviors of impurities, the conditions of cesium and barium precipitation were surveyed and it was clarified that there were most impurities on the

  16. Contribution to the study of the process of purification of plutonium by extraction with trilaurylamine

    International Nuclear Information System (INIS)

    Saey, Jean-Claude

    1966-01-01

    This work addresses the process of plutonium purification which uses trilaurylamine nitrate. In order to use this nitrate in its solid state and at ordinary temperature, a secondary solvent must be added which must have some properties: low volume mass and viscosity, high boiling and ignition temperatures, rather low miscibility with water, high stability in front of joint actions of nitric acid and radiations, and no reaction with the alkylammonium nitrate and the complex. Thus, the author addresses phenomena of immiscibility and identifies some important molecular characteristics which could lead to the selection of another secondary solvent than dodecane. The decalin seem interesting and its behaviour is studied. A mixing of dodecane and decalin is used as extraction mixing. The obtained results are discussed. Finally, the author notices that using this mixing in the plutonium purification process results in a large increase of metal concentrations and a decrease of risks of crystallisation, without any major drawback, in a continuously operating micro-industrial installation

  17. Nonviral pulmonary delivery of siRNA.

    Science.gov (United States)

    Merkel, Olivia M; Kissel, Thomas

    2012-07-17

    RNA interference (RNAi) is an important part of the cell's defenses against viruses and other foreign genes. Moreover, the biotechnological exploitation of RNAi offers therapeutic potential for a range of diseases for which drugs are currently unavailable. Unfortunately, the small interfering RNAs (siRNAs) that are central to RNAi in the cytoplasm are readily degradable by ubiquitous nucleases, are inefficiently targeted to desired organs and cell types, and are excreted quickly upon systemic injection. As a result, local administration techniques have been favored over the past few years, resulting in great success in the treatment of viral infections and other respiratory disorders. Because there are several advantages of pulmonary delivery over systemic administration, two of the four siRNA drugs currently in phase II clinical trials are delivered intranasally or by inhalation. The air-blood barrier, however, has only limited permeability toward large, hydrophilic biopharmaceuticals such as nucleic acids; in addition, the lung imposes intrinsic hurdles to efficient siRNA delivery. Thus, appropriate formulations and delivery devices are very much needed. Although many different formulations have been optimized for in vitro siRNA delivery to lung cells, only a few have been reported successful in vivo. In this Account, we discuss both obstacles to pulmonary siRNA delivery and the success stories that have been achieved thus far. The optimal pulmonary delivery vehicle should be neither cytotoxic nor immunogenic, should protect the payload from degradation by nucleases during the delivery process, and should mediate the intracellular uptake of siRNA. Further requirements include the improvement of the pharmacokinetics and lung distribution profiles of siRNA, the extension of lung retention times (through reduced recognition by macrophages), and the incorporation of reversible or stimuli-responsive binding of siRNA to allow for efficient release of the siRNAs at the

  18. Customization of copolymers to optimize selectivity and yield in polymer-driven antibody purification processes.

    Science.gov (United States)

    Capito, Florian; Skudas, Romas; Stanislawski, Bernd; Kolmar, Harald

    2013-01-01

    This manuscript describes customization of copolymers to be used for polymer-driven protein purification in bioprocessing. To understand how copolymer customization can be used for fine-tuning, precipitation behavior was analyzed for five target antibodies (mAbs) and BSA as model impurity protein, at ionic strength similar to undiluted cell culture fluid. In contrast to the use of standardized homopolymers, customized copolymers, composed of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and 4-(acryloylamino)benzoic acid (ABZ), exhibited antibody precipitation yields exceeding 90%. Additionally, copolymer average molecular weight (Mw ) was varied and its influence on precipitation yield and contaminant coprecipitation was investigated. Results revealed copolymer composition as the major driving force for precipitation selectivity, which was also dependent on protein hydrophobicity. By adjusting ABZ content and Mw of the precipitant for each of the mAbs, conditions were found that allowed for high precipitation yield and selectivity. These findings may open up new avenues for using polymers in antibody purification processes. © 2013 American Institute of Chemical Engineers.

  19. Process and economic evaluation of the extraction and purification of recombinant beta-glucuronidase from transgenic corn

    Science.gov (United States)

    Evangelista; Kusnadi; Howard; Nikolov

    1998-07-01

    A process model for the recovery and purification of recombinant beta-glucuronidase (rGUS) from transgenic corn was developed, and the process economics were estimated. The base-case bioprocessing plant operates 7500 h/year processing 1.74 million (MM) kg of transgenic corn containing 0.015% (db) rGUS. The process consists of milling the corn into flour, extraction of protein by using 50 mM sodium phosphate buffer, and rGUS purification by ion exchange and hydrophobic interaction chromatography. About 137 kg of rGUS of 83% (db) purity can be produced annually. The production cost amounted to $43 000/kg of rGUS. The cost of milling, protein extraction, and rGUS purification accounted for 6, 40, and 48% of annual operating cost, respectively. The cost of transgenic corn was 31% of the raw material costs or 6% of the annual operating cost. About 78% of the cost of buffer and water were incurred in the protein extraction section, while 88% of other consumables were from the purification section. The sensitivity analysis indicated that rGUS can be produced profitably from corn even at the 0.015% (db) expression level, assuming a selling price of $100 000/kg GUS. An increase in rGUS expression levels up to 0.08% significantly improves the process economics.

  20. Finite Element Modeling of Adsorption Processes for Gas Separation and Purification

    International Nuclear Information System (INIS)

    Humble, Paul H.; Williams, Richard M.; Hayes, James C.

    2009-01-01

    Pacific Northwest National Laboratory (PNNL) has expertise in the design and fabrication of automated radioxenon collection systems for nuclear explosion monitoring. In developing new systems there is an ever present need to reduce size, power consumption and complexity. Most of these systems have used adsorption based techniques for gas collection and/or concentration and purification. These processes include pressure swing adsorption, vacuum swing adsorption, temperature swing adsorption, gas chromatography and hybrid processes that combine elements of these techniques. To better understand these processes, and help with the development of improved hardware, a finite element software package (COMSOL Multiphysics) has been used to develop complex models of these adsorption based operations. The partial differential equations used include a mass balance for each gas species and adsorbed species along with a convection conduction energy balance equation. These equations in conjunction with multicomponent temperature dependent isotherm models are capable of simulating separation processes ranging from complex multibed PSA processes, and multicomponent temperature programmed gas chromatography, to simple two component temperature swing adsorption. These numerical simulations have been a valuable tool for assessing the capability of proposed processes and optimizing hardware and process parameters.

  1. Environmental Management in the Process of Purification of Cuban Furfural in the Chemical Bioactive Center Plant

    Directory of Open Access Journals (Sweden)

    Ing. Liset Rodríguez-Machín

    2016-02-01

    Full Text Available It is necessary to establish in the installed equipment, operating conditions and quality specifications in the purification of furfural produced in Cuba. To do this some literature review and experiments are carried out. The approved batches by the quality control are quantified as well as the heat and evaporation losses and the impact on workers health. Energy management is performed by identifying electricity as the energy source of higher consumption. Some measures are applied like coating the evaporator portions that are required together with condenser modification and improvement of the room ventilation. As a result it was shown that it is possible to purify the Cuban furfural in the installed equipment, the process efficiency increases in 5,5 %, the evaporation losses decrease and non-acceptance by quality control drops. If the imported furfural is replaced by the Cuban are saved about 39 000 • per year production.

  2. Processing and removal of the Three Mile Island makeup and purification system resins

    International Nuclear Information System (INIS)

    Reilly, J.K.; McIntosh, T.W.; Northey, L.M.; GaTanto, J.J.; Osterhoudt, T.R.; Thompson, J.D.

    1985-01-01

    The accident at Three Mile Island Unit 2 in March 1979 left the makeup and purification demineralizers inaccessible to workers. These demineralizers contained the highest concentrations of radioactive isotopes outside the Reactor Building. Additionally, unknown quantities of fuel were in the demineralizers. Other concerns centered on the unknown condition of the demineralizer resins, the possible loss of system integrity, and the presence of hydrogen due to the radiolytic breakdown of water contained in the demineralizers. GPU Nuclear, with the US Department of Energy and its contractors EG and G Idaho, Inc., Oak Ridge National Laboratory, and Westinghouse Hanford Company, remotely measured the fuel and fission product inventory of the demineralizers and demonstrated a practical chemical processing method using samples acquired from the demineralizers. Equipment was developed and installed to elute the radioactive cesium from the demineralizers. And elution, which began in September 1984 now nears completion

  3. [Studies on purification of total glycosides of paeony (TGP) from Paeonia lactiflora by ethanol gradient combined with resin processing].

    Science.gov (United States)

    Shu, Xin-Ying; Meng, Xian-Sheng; Pan, Ying; Han, Ling; Bao, Yong-Rui; Guo, Xiao-Rui

    2010-11-01

    To study the purification technology of TGP from Paeonia lactiflora by ethanol gradient combined with resin processing and determine the optimum technological conditions and parameters. Using orthogonal test design to investigate the effect of ethanol gradient treatment on the content of TGP. Moreover, from the static and dynamic adsorption nine types of macroporous adsorption resin were evaluated to select the best resin type and the optimum separation and purification conditions. The best technology of Paeonia lactiflora ethanol precipitation was concentration of 1 g crude drug/mL precipitated by 95% ethanol to 90% concentration and then frozen for 10 h. HPD300 resin was the optimal model for the separation and purification of TGP from Paeonia lactiflora, with 5BV of 50% ethanol eluenting and the ratio of herb to resin was 2:1 . This technology is suitable and advanced for industry production and it is simple and convenient, rapid, accurate, etc.

  4. Optimization‐based framework for resin selection strategies in biopharmaceutical purification process development

    Science.gov (United States)

    Liu, Songsong; Gerontas, Spyridon; Gruber, David; Turner, Richard; Titchener‐Hooker, Nigel J.

    2017-01-01

    This work addresses rapid resin selection for integrated chromatographic separations when conducted as part of a high‐throughput screening exercise during the early stages of purification process development. An optimization‐based decision support framework is proposed to process the data generated from microscale experiments to identify the best resins to maximize key performance metrics for a biopharmaceutical manufacturing process, such as yield and purity. A multiobjective mixed integer nonlinear programming model is developed and solved using the ε‐constraint method. Dinkelbach's algorithm is used to solve the resulting mixed integer linear fractional programming model. The proposed framework is successfully applied to an industrial case study of a process to purify recombinant Fc Fusion protein from low molecular weight and high molecular weight product related impurities, involving two chromatographic steps with eight and three candidate resins for each step, respectively. The computational results show the advantage of the proposed framework in terms of computational efficiency and flexibility. © 2017 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers Biotechnol. Prog., 33:1116–1126, 2017 PMID:28393478

  5. Oil quality of passion fruit seeds subjected to a pulp-waste purification process

    Directory of Open Access Journals (Sweden)

    Suelen Alvarenga Regis

    2015-06-01

    Full Text Available Passion fruit seeds must be clean and dry before the extraction processing to obtain high-quality oil for edible and cosmetic purposes. This research studies the viability of a cleaning process of seeds by evaluating the oil quality. The research examined 2 maturation stages of the fruit and one purification process of the seeds, compared to the control. The oil quality was evaluated by fatty acid composition, acidity, peroxide value and oxidative stability. The pulp waste suffered a thermal treatment in an alkaline water solution at 60°C for 10min and was further purified in an experimental decanter. In the control treatment, the pulp waste was processed using only water at ambient conditions. The passion fruit seeds were totally cleaned by the thermal/chemical treatment, allowing a faster drying (less than 50% of the drying time of the seeds and a bit higher yield of oil extraction (proportionally around 7.7%, without changes in quality of the oil

  6. Application and improvement of reciprocating-sieve plate extraction column in natural uranium extraction and purification process

    International Nuclear Information System (INIS)

    Wang Xuejun; Li Linyan; Liu Jing; Liu Xin; Yang Lifeng; Xiao Shaohua; Liu Hao

    2013-01-01

    Reciprocating-sieve plate extraction column is commonly used in the extraction process. Optimization and application were conducted successfully via production practice in some chemical and pharmaceutical plants, and good results are obtained while it is applied in the natural uranium extraction and purification process. The key component of reciprocating-sieve plate extraction column is gear-drive equipment in which drive motor serves as its core. Hence, it is important to select appropriate mode of speed regulation. In this paper, the principle and performance of several mode of speed regulation are compared. Both electromagnetic slip and frequency speed-regulation can be applied in general industrial process, but frequency speed-regulation with low energy cost can be used in wider operating range. The application of frequency speed-regulation mode used in reciprocating-sieve plate extraction column will increase the convenience and stability of natural uranium extraction and purification process. (authors)

  7. CONTINUOUS CHELATION-EXTRACTION PROCESS FOR THE SEPARATION AND PURIFICATION OF METALS

    Science.gov (United States)

    Thomas, J.R.; Hicks, T.E.; Rubin, B.; Crandall, H.W.

    1959-12-01

    A continuous process is presented for separating metal values and groups of metal values from each other. A complex mixture. e.g., neutron-irradiated uranium, can be resolved into component parts. In the present process the values are dissolved in an acidic solution and adjusted to the proper oxidation state. Thenceforth the solution is contacted with an extractant phase comprising a fluorinated beta -diketone in an organic solvent under centain pH conditions whereupon plutonium and zirconium are extracted. Plutonium is extracted from the foregoing extract with reducing aqueous solutions or under specified acidic conditions and can be recovered from the aqueous solution. Zirconium is then removed with an oxalic acid aqueous phase. The uranium is recovered from the residual original solution using hexone and hexone-diketone extractants leaving residual fission products in the original solution. The uranium is extracted from the hexone solution with dilute nitric acid. Improved separations and purifications are achieved using recycled scrub solutions and the "self-salting" effect of uranyl ions.

  8. Is the phototransformation of pharmaceuticals a natural purification process that decreases ecological and human health risks?

    International Nuclear Information System (INIS)

    Wang, Xiao-Huan; Lin, Angela Yu-Chen

    2014-01-01

    Sunlight photodegradation has long been considered a significant process in lowering the concentrations of pharmaceuticals in surface waters and thus decreasing the ecological risk. For the first time, this study identified the significance of investigating the environmental photodegradation of a pharmaceutical residue mixture (rather than a single compound) and the associated toxicity of transformation byproducts in environmental waters, including rivers, hospital wastewaters, and effluents from wastewater treatment plants and pharmaceutical production facilities. Pharmaceuticals undergo phototransformation rather than mineralization (11–23% in 34 h). Pharmaceutical mixtures could possibly act as dissolved organic matter for each individual compound and subsequently affect the photolysis rates. The increased toxicity of irradiated pharmaceutical mixtures challenges the validity of the current understanding of sunlight photolysis. The implications of this work suggest that current knowledge concerning the occurrence, natural attenuation, ecotoxicity, and human health risks of pharmaceuticals is far from complete; photolysis is not necessarily a purification process. -- Highlights: • Pharmaceutical mixtures could possibly act as DOMs for each other. • Pharmaceuticals underwent merely phototransformation rather than mineralization. • Increased toxicity from photo byproducts associated with the pharmaceutical mixture. • Phototransformation does not necessary mitigate the risk to human and the ecosystem. -- Transformation byproducts associated with a pharmaceutical mixture could be more toxic, and phototransformation does not necessary mitigate the risk to humans and the ecosystem

  9. Evaluation of strategies to control Fab light chain dimer during mammalian expression and purification: A universal one-step process for purification of correctly assembled Fab.

    Science.gov (United States)

    Spooner, Jennifer; Keen, Jenny; Nayyar, Kalpana; Birkett, Neil; Bond, Nicholas; Bannister, David; Tigue, Natalie; Higazi, Daniel; Kemp, Benjamin; Vaughan, Tristan; Kippen, Alistair; Buchanan, Andrew

    2015-07-01

    Fabs are an important class of antibody fragment as both research reagents and therapeutic agents. There are a plethora of methods described for their recombinant expression and purification. However, these do not address the issue of excessive light chain production that forms light chain dimers nor do they describe a universal purification strategy. Light chain dimer impurities and the absence of a universal Fab purification strategy present persistent challenges for biotechnology applications using Fabs, particularly around the need for bespoke purification strategies. This study describes methods to address light chain dimer formation during Fab expression and identifies a novel CH 1 affinity resin as a simple and efficient one-step purification for correctly assembled Fab. © 2015 Wiley Periodicals, Inc.

  10. Using pattern classification and nuclear forensic signatures to link UOC to source rocks and purification processes

    International Nuclear Information System (INIS)

    Marks, N.; Robel, M.; Borg, M.; Hutcheon, I.; Kristo, M.

    2014-01-01

    Nuclear forensics is a scientific discipline interfacing law enforcement, nuclear science and nonproliferation. Information on the history and on the potential origin of unknown nuclear material can be obtained through nuclear forensic analysis. Using commonly available techniques of mass spectrometry, microscopy and x-ray diffraction, we have gained insight into the processing and origin of a suite of uranium ore concentrate (UOC) samples. We have applied chemometric techniques to investigate the relationships between uranium ore deposits and UOC samples in order to identify chemical and isotopic signatures of nuclear forensic importance. We developed multivariate signatures based on elemental concentrations and isotope ratios using a database of characteristics of UOC originating throughout the world. By introducing detailed and specific information about the source rock geology for each sample, we improved our understanding of the preservation of forensic signatures in UOC. Improved characterization of sample processing and provenance allows us to begin to assess the statistical significance of different groupings of samples and identify underlying patterns. Initial results indicate the concentration of uranium in the ore body, the geochemical conditions associated with uranium emplacement, and host rock petrogenesis exert controlling influences on the impurities preserved in UOC. Specific ore processing techniques, particularly those related to In-Situ Recovery, are also reflected in UOC impurity signatures. Stable and radiogenic isotope geochemistry can be used in conjunction with rare earth element patterns and other characteristics to link UOCs to specific geologic deposits of origin. We will present a number of case studies illustrating the ways in which nuclear forensic analysis can provide insight into the ore geology and production and purification processes used to produce UOC. (author)

  11. Purification and treatment of industrial wastewater by electron beam process: it's potential and effectiveness evaluation

    International Nuclear Information System (INIS)

    Zulkafli Ghazali; Khomsaton Abu Bakar; Ting Teo Ming; Siti Aiasah Hashim; Khairul Zaman Mohd Dahlan

    2002-01-01

    Demand for water has grown dramatically globally. We have seen how acute is the demand for treated water in Malaysia during dry spell of late. Between 1900 and 1995, water consumption increased by over six times, globally, more than double the rate of population growth. This rapid growth in water demand is due to the increasing reliance on irrigation to achieve food security, the growth of industries, and the increasing use for domestic purposes. Given the seriousness of the situation and future risk of crises, there is an urgent need to develop the water-efficient technologies including economical treatment methods of wastewater and polluted water. Electron beam treatment (E-Beam treatment) is a comparatively new method of wastewater purification. E-beam treatment is also an environment-friendly approach for the cleanup of contaminated groundwater and industrial wastewater. E-beam treatment treats multi-components waste streams and does not require any hazardous chemical additives nor does it create any secondary wastes. It uses fast formation of short-lived reactive particles, which are capable of efficient decomposition of pollutants inside wastewater. This paper highlights the practical treatment of wastewater using E-Beam method that gives essential conveniences and advantages of the followings: - strongest reducing and oxidizing agents; - universality and interchangeability of redox agents; - variety of paths for pollutant conversion; - process controllability; - wide choice of equipment and technological regimes; - compatibility with conventional methods. (Author)

  12. Liquid-liquid extraction for purification of wet process phosphoric acid

    International Nuclear Information System (INIS)

    Lotfollahi, Mohammad Nader; Bakshi, Mahdi

    2006-01-01

    The Wet Process Phosphoric Acid (WPA) is used to produce fertilizers and alimentary supplies for cattle. In each of these applications, the impurities contained in acid must be in standard range. In this paper purification of WPA by solvent extraction is performed and the effect of the mass ratio of solvent to feed on extraction efficiency is studied. The working solvents are Methyl Iso Butyl Ketone (MIBK), Iso Amyl Alcohol (IAA) and the mixture of them. The results show that the IAA is better than other solvents in extraction of WPA. This solvent can extract 82.2% of acid after two extraction stages but MIBK can extract only 73.5% of acid after three extraction stages. For all of these solvents, the Pb and Cd concentrations go down to trace. The experimental results show that the maximum separation of Mg with MIBK is 87.5% which occurs at the mass ratio of solvent to feed eual to 4. In the case of IAA solvent the percent is 91.7% and the ratio is 8

  13. A sulfuric-lactic acid process for efficient purification of fungal chitosan with intact molecular weight.

    Science.gov (United States)

    Naghdi, Mitra; Zamani, Akram; Karimi, Keikhosro

    2014-02-01

    The most recent method of fungal chitosan purification, i.e., two steps of dilute sulfuric acid treatment, pretreatment of cell wall at room temperature for phosphate removal and extraction of chitosan from the phosphate free cell wall at high temperature, significantly reduces the chitosan molecular weight. This study was aimed at improvement of this method. In the pretreatment step, to choose the best conditions, cell wall of Rhizopus oryzae, containing 9% phosphate, 10% glucosamine, and 21% N-acetyl glucosamine, was treated with sulfuric, lactic, acetic, nitric, or hydrochloric acid, at room temperature. Sulfuric acid showed the best performance in phosphate removal (90%) and cell wall recovery (89%). To avoid depolymerisation of chitosan, hot sulfuric acid extraction was replaced with lactic acid treatment at room temperature, and a pure fungal chitosan was obtained (0.12 g/g cell wall). Similar pretreatment and extraction processes were conducted on pure shrimp chitosan and resulted in a chitosan recovery of higher than 87% while the reduction of chitosan viscosity was less than 15%. Therefore, the sulfuric-lactic acid method purified the fungal chitosan without significant molecular weight manipulation. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Air Stripping Designs and Reactive Water Purification Processes for the Lunar Surface

    Science.gov (United States)

    Boul, Peter J.; Lange, Kevin; Conger, Bruce; Anderson, Molly

    2010-01-01

    Air stripping designs are considered to reduce the presence of volatile organic compounds in the purified water. Components of the wastewater streams are ranked by Henry's Law Constant and the suitability of air stripping in the purification of wastewater in terms of component removal is evaluated. Distillation processes are modeled in tandem with air stripping to demonstrate the potential effectiveness and utility of these methods in recycling wastewater on the Moon. Scaling factors for distillation and air stripping columns are presented to account for the difference in the lunar gravitation environment. Commercially available distillation and air stripping units which are considered suitable for Exploration Life Support are presented. The advantages to the various designs are summarized with respect to water purity levels, power consumption, and processing rates. An evaluation of reactive distillation and air stripping is presented with regards to the reduction of volatile organic compounds in the contaminated water and air. Among the methods presented, an architecture is presented for the evaluation of the simultaneous oxidation of organics in air and water. These and other designs are presented in light of potential improvements in power consumptions and air and water purities for architectures which include catalytic activity integrated into the water processor. In particular, catalytic oxidation of organics may be useful as a tool to remove contaminants that more traditional distillation and/or air stripping columns may not remove. A review of the current leading edge at the commercial level and at the research frontier in catalytically active materials is presented. Themes and directions from the engineering developments in catalyst design are presented conceptually in light of developments in the nanoscale chemistry of a variety of catalyst materials.

  15. Investigation of a miRNA-Induced Gene Silencing Technique in Petunia Reveals Alterations in miR173 Precursor Processing and the Accumulation of Secondary siRNAs from Endogenous Genes.

    Directory of Open Access Journals (Sweden)

    Yao Han

    Full Text Available MIGS (miRNA-induced gene silencing is a straightforward and efficient gene silencing technique in Arabidopsis. It works by exploiting miR173 to trigger the production of phasiRNAs (phased small interfering RNAs. MIGS can be used in plant species other than Arabidopsis by co-expression of miR173 and target gene fragments fused to an upstream miR173 target site. However, the efficiency and technical mechanisms have not been thoroughly investigated in other plants. In this work, two vectors, pMIGS-chs and pMIGS-pds, were constructed and transformed into petunia plants. The transgenic plants showed CHS (chalcone synthase and PDS (phytoene desaturase gene-silencing phenotypes respectively, indicating that MIGS functions in petunia. MIGS-chs plants were used to investigate the mechanisms of this technique in petunia. Results of 5'- RACE showed that the miR173 target site was cleaved at the expected position and that endogenous CHS genes were cut at multiple positions. Small RNA deep sequencing analysis showed that the processing of Arabidopsis miR173 precursors in MIGS-chs transgenic petunia plants did not occur in exactly the same way as in Arabidopsis, suggesting differences in the machinery of miRNA processing between plant species. Small RNAs in-phase with the miR173 cleavage register were produced immediately downstream from the cleavage site and out-of-phase small RNAs were accumulated at relatively high levels from processing cycle 5 onwards. Secondary siRNAs were generated from multiple sites of endogenous CHS-A and CHS-J genes, indicating that miR173 cleavage induced siRNAs have the same ability to initiate siRNA transitivity as the siRNAs functioning in co-suppression and hpRNA silencing. On account of the simplicity of vector construction and the transitive amplification of signals from endogenous transcripts, MIGS is a good alternative gene silencing method for plants, especially for silencing a cluster of homologous genes with redundant

  16. Investigation of a miRNA-Induced Gene Silencing Technique in Petunia Reveals Alterations in miR173 Precursor Processing and the Accumulation of Secondary siRNAs from Endogenous Genes.

    Science.gov (United States)

    Han, Yao; Zhang, Bin; Qin, Xiaoting; Li, Mingyang; Guo, Yulong

    2015-01-01

    MIGS (miRNA-induced gene silencing) is a straightforward and efficient gene silencing technique in Arabidopsis. It works by exploiting miR173 to trigger the production of phasiRNAs (phased small interfering RNAs). MIGS can be used in plant species other than Arabidopsis by co-expression of miR173 and target gene fragments fused to an upstream miR173 target site. However, the efficiency and technical mechanisms have not been thoroughly investigated in other plants. In this work, two vectors, pMIGS-chs and pMIGS-pds, were constructed and transformed into petunia plants. The transgenic plants showed CHS (chalcone synthase) and PDS (phytoene desaturase) gene-silencing phenotypes respectively, indicating that MIGS functions in petunia. MIGS-chs plants were used to investigate the mechanisms of this technique in petunia. Results of 5'- RACE showed that the miR173 target site was cleaved at the expected position and that endogenous CHS genes were cut at multiple positions. Small RNA deep sequencing analysis showed that the processing of Arabidopsis miR173 precursors in MIGS-chs transgenic petunia plants did not occur in exactly the same way as in Arabidopsis, suggesting differences in the machinery of miRNA processing between plant species. Small RNAs in-phase with the miR173 cleavage register were produced immediately downstream from the cleavage site and out-of-phase small RNAs were accumulated at relatively high levels from processing cycle 5 onwards. Secondary siRNAs were generated from multiple sites of endogenous CHS-A and CHS-J genes, indicating that miR173 cleavage induced siRNAs have the same ability to initiate siRNA transitivity as the siRNAs functioning in co-suppression and hpRNA silencing. On account of the simplicity of vector construction and the transitive amplification of signals from endogenous transcripts, MIGS is a good alternative gene silencing method for plants, especially for silencing a cluster of homologous genes with redundant functions.

  17. Stress analysis of the O-element pipe during the process of flue gases purification

    Directory of Open Access Journals (Sweden)

    Nekvasil R.

    2008-11-01

    Full Text Available Equipment for flue gases purification from undesired substances is used throughout power and other types of industry. This paper deals with damaging of the O-element pipe designed to remove sulphur from the flue gases, i.e. damaging of the pipe during flue gases purification. This purification is conducted by spraying the water into the O-shaped pipe where the flue gases flow. Thus the sulphur binds itself onto the water and gets removed from the flue gas. Injection of cold water into hot flue gases, however, causes high stress on the inside of the pipe, which can gradually damage the O-element pipe. In this paper initial injection of water into hot pipe all the way to stabilization of temperature fields will be analyzed and the most dangerous places which shall be considered for fatigue will be determined.

  18. A dominant mutation in mediator of paramutation2, one of three second-largest subunits of a plant-specific RNA polymerase, disrupts multiple siRNA silencing processes.

    Science.gov (United States)

    Sidorenko, Lyudmila; Dorweiler, Jane E; Cigan, A Mark; Arteaga-Vazquez, Mario; Vyas, Meenal; Kermicle, Jerry; Jurcin, Diane; Brzeski, Jan; Cai, Yu; Chandler, Vicki L

    2009-11-01

    Paramutation involves homologous sequence communication that leads to meiotically heritable transcriptional silencing. We demonstrate that mop2 (mediator of paramutation2), which alters paramutation at multiple loci, encodes a gene similar to Arabidopsis NRPD2/E2, the second-largest subunit of plant-specific RNA polymerases IV and V. In Arabidopsis, Pol-IV and Pol-V play major roles in RNA-mediated silencing and a single second-largest subunit is shared between Pol-IV and Pol-V. Maize encodes three second-largest subunit genes: all three genes potentially encode full length proteins with highly conserved polymerase domains, and each are expressed in multiple overlapping tissues. The isolation of a recessive paramutation mutation in mop2 from a forward genetic screen suggests limited or no functional redundancy of these three genes. Potential alternative Pol-IV/Pol-V-like complexes could provide maize with a greater diversification of RNA-mediated transcriptional silencing machinery relative to Arabidopsis. Mop2-1 disrupts paramutation at multiple loci when heterozygous, whereas previously silenced alleles are only up-regulated when Mop2-1 is homozygous. The dramatic reduction in b1 tandem repeat siRNAs, but no disruption of silencing in Mop2-1 heterozygotes, suggests the major role for tandem repeat siRNAs is not to maintain silencing. Instead, we hypothesize the tandem repeat siRNAs mediate the establishment of the heritable silent state-a process fully disrupted in Mop2-1 heterozygotes. The dominant Mop2-1 mutation, which has a single nucleotide change in a domain highly conserved among all polymerases (E. coli to eukaryotes), disrupts both siRNA biogenesis (Pol-IV-like) and potentially processes downstream (Pol-V-like). These results suggest either the wild-type protein is a subunit in both complexes or the dominant mutant protein disrupts both complexes. Dominant mutations in the same domain in E. coli RNA polymerase suggest a model for Mop2-1 dominance

  19. Improved laboratory assays of Pu and U for SRP purification and finishing processes

    International Nuclear Information System (INIS)

    Holland, M.K.; Dorsett, R.S.

    1986-01-01

    Significant improvements have been made in routine assay techniques for uranium and plutonium as part of an effort to improve accountability at the Savannah River Plant (SRP). Emphasis was placed on input/output accountability points and key physical inventory tanks associated with purification and finishing processes. Improvements were made in existing assay methods; new methods were implemented; and the application of these methods was greatly expanded. Prior to assays, samples were validated via density measurements. Digital density meters precise to four, five, and six decimal places were used to meet specific requirements. Improved plutonium assay techniques are now in routine use: controlled-potential coulometry, ion-exchange coulometry, and Pu(III) diode-array spectrophotometry. A new state-of-the-art coulometer was fabricated and used to ensure maximum accuracy in verifying standards and in measuring plutonium in product streams. The diode-array spectrophotometer for Pu(III) measurements was modified with fiber optics to facilitate remote measurements; rapid, precise measurements made the technique ideally suited for high-throughput assays. For uranium assays, the isotope-dilution mass spectrometric (IDMS) method was converted to a gravimetric basis. The IDMS method and the existing Davies-Gray titration (gravimetric basis) have met accountability requirements for uranium. More recently, a Pu(VI) diode-array spectrophotometric method was used on a test basis to measure plutonium in shielded-cell input accountability samples. In addition, tests to measure uranium via diode-array spectrophotometry were initiated. This rapid, precise method will replace IDMS for certain key sample points

  20. Cleanex process: a versatile solvent extraction process for recovery and purification of lanthanides, americium, and curium

    International Nuclear Information System (INIS)

    Bigelow, J.E.; Collins, E.D.; King, L.J.

    1979-01-01

    At a concentration of 1 M in straight-chain hydrocarbon diluent, HDEHP will extract americium, curium, and other trivalent actinide and lanthanide elements from dilute acid or salt solutions. The solute is back-extracted with more concentrated acid, either nitric or hydrochloric. The process has been used in the continuous, countercurrent mode, but its greatest advantage arises in batch extractions where the excess acid can be titrated with NaOH to produce a final acidity of about 0.03 M. Under these conditions, 99% recovery can be achieved, usually in one stage. Cleanex was used on the 50-liter scale at the Transuranium Processing Plant at Oak Ridge for 12 years to provide a broad spectrum cleanup to transuranium elements before applying more sophisticated techniques for separating individual products. The process is also used routinely to recover excessive losses of curium and/or californium from plant waste streams. The solvent system is relatively resistant to radiation damage, being usable up to 200 W-h/liter

  1. TIO2 based photocatalytic gas purification: the effects of co-catalysts and process conditions

    NARCIS (Netherlands)

    Fraters, B.D.

    2015-01-01

    Photocatalysis is highly promising as a technology to mitigate environmental pollution. In this thesis the focus will be on air purification by photocatalytic oxidation of volatile organic compounds (VOC’s). A major challenge in photocatalysis is the low photonic efficiency, due to high electron

  2. Process for purification of waste water produced by a Kraft process pulp and paper mill

    Science.gov (United States)

    Humphrey, M. F. (Inventor)

    1979-01-01

    The water from paper and pulp wastes obtained from a mill using the Kraft process is purified by precipitating lignins and lignin derivatives from the waste stream with quaternary ammonium compounds, removing other impurities by activated carbon produced from the cellulosic components of the water, and then separating the water from the precipitate and solids. The activated carbon also acts as an aid to the separation of the water and solids. If recovery of lignins is also desired, then the precipitate containing the lignins and quaternary ammonium compounds is dissolved in methanol. Upon acidification, the lignin is precipitated from the solution. The methanol and quaternary ammonium compound are recovered for reuse from the remainder.

  3. Statistical and Judgmental Criteria for Scale Purification

    DEFF Research Database (Denmark)

    Wieland, Andreas; Durach, Christian F.; Kembro, Joakim

    2017-01-01

    of scale purification, to critically analyze the current state of scale purification in supply chain management (SCM) research and to provide suggestions for advancing the scale-purification process. Design/methodology/approach A framework for making scale-purification decisions is developed and used...

  4. Electrocoagulation and nanofiltration integrated process application in purification of bilge water using response surface methodology.

    Science.gov (United States)

    Akarsu, Ceyhun; Ozay, Yasin; Dizge, Nadir; Elif Gulsen, H; Ates, Hasan; Gozmen, Belgin; Turabik, Meral

    Marine pollution has been considered an increasing problem because of the increase in sea transportation day by day. Therefore, a large volume of bilge water which contains petroleum, oil and hydrocarbons in high concentrations is generated from all types of ships. In this study, treatment of bilge water by electrocoagulation/electroflotation and nanofiltration integrated process is investigated as a function of voltage, time, and initial pH with aluminum electrode as both anode and cathode. Moreover, a commercial NF270 flat-sheet membrane was also used for further purification. Box-Behnken design combined with response surface methodology was used to study the response pattern and determine the optimum conditions for maximum chemical oxygen demand (COD) removal and minimum metal ion contents of bilge water. Three independent variables, namely voltage (5-15 V), initial pH (4.5-8.0) and time (30-90 min) were transformed to coded values. The COD removal percent, UV absorbance at 254 nm, pH value (after treatment), and concentration of metal ions (Ti, As, Cu, Cr, Zn, Sr, Mo) were obtained as responses. Analysis of variance results showed that all the models were significant except for Zn (P > 0.05), because the calculated F values for these models were less than the critical F value for the considered probability (P = 0.05). The obtained R(2) and Radj(2) values signified the correlation between the experimental data and predicted responses: except for the model of Zn concentration after treatment, the high R(2) values showed the goodness of fit of the model. While the increase in the applied voltage showed negative effects, the increases in time and pH showed a positive effect on COD removal efficiency; also the most effective linear term was found as time. A positive sign of the interactive coefficients of the voltage-time and pH-time systems indicated synergistic effect on COD removal efficiency, whereas interaction between voltage and pH showed an antagonistic

  5. Purification of Sodium Phosphates as by Product of Rirang Ore Decomposition Process

    International Nuclear Information System (INIS)

    Sugeng-Walujo; Hafni-LN; Susilaningtyas; Mukhlis; Budi-Sarono; Widowati

    2004-01-01

    The aim of this experiment is to get purification condition of sodium phosphates from the filtration result of mixing mother liquor and filtrate of washing residue from Rirang monazite decomposition by alkaline. The method of purification which has been used is dissolved the precipitation of sodium phosphates into agitated water 5 minutes and solution settling for 12 hours until appear of sodium phosphate crystals. The variable of experiment included dissolution time and ratio of the amount precipitate sodium phosphate volume of water to solvent. Experimental data shown that the good temperature of dissolution is 70 o C with the ratio of precipitate sodium phosphate is 80 gram/ 40 ml to water. The recovery of sodium phosphate crystallisation is 87.4314 % with 54.0105 % pure of Na 3 PO 4 , U content is 0.0004%, NaOH content and other impurities is 45.9889%. (author)

  6. The development and testing of the new flowsheets for the plutonium purification of the Purex process

    Energy Technology Data Exchange (ETDEWEB)

    Bugrov, K.V.; Korotaev, V.G.; Korchenkin, K.K.; Logunov, M.V.; Ludin, S.A.; Mashkin, A.N.; Melentev, A.B.; Samarina, N.S. [FSUE ' PAMayak' , Lenin st., 35, Ozersk 456780 (Russian Federation)

    2016-07-01

    In order to improve the extraction flowsheet of RT-1 Plant two versions of plutonium purification unit flowsheet were developed: a flowsheet with stabilization of Pu(IV)-Np(IV) valence pair and Pu, Np co-recovery, and a flowsheet with stabilization of Pu(IV)-Np(V) valence pair and Pu recovery. The task related to stabilization of the valence pair of the target components in the required state was solved with the use of reactants already applied at RT-1 Plant, namely, hydrogen peroxide, hydrazine nitrate and catalyst (Fe). Both flowsheets were adapted for the plant purification facility with minimum modifications of the equipment, and passed the full scale industrial testing. As a result of this work, reduction in volume and salt content of the raffinate was achieved. (authors)

  7. A Hybrid MPC-PID Control System Design for the Continuous Purification and Processing of Active Pharmaceutical Ingredients

    Directory of Open Access Journals (Sweden)

    Maitraye Sen

    2014-05-01

    Full Text Available In this work, a hybrid MPC (model predictive control-PID (proportional-integral-derivative control system has been designed for the continuous purification and processing framework of active pharmaceutical ingredients (APIs. The specific unit operations associated with the purification and processing of API have been developed from first-principles and connected in a continuous framework in the form of a flowsheet model. These integrated unit operations are highly interactive along with the presence of process delays. Therefore, a hybrid MPC-PID is a promising alternative to achieve the desired control loop performance as mandated by the regulatory authorities. The integrated flowsheet model has been simulated in gPROMSTM (Process System Enterprise, London, UK. This flowsheet model has been linearized in order to design the control scheme. The ability to track the set point and reject disturbances has been evaluated. A comparative study between the performance of the hybrid MPC-PID and a PID-only control scheme has been presented. The results show that an enhanced control loop performance can be obtained under the hybrid control scheme and demonstrate that such a scheme has high potential in improving the efficiency of pharmaceutical manufacturing operations.

  8. Behaviour analysis of uranium purification pilot plant taking into consideration the incorporation of a second column of extraction in the process flow chart

    International Nuclear Information System (INIS)

    Souza Barbosa, E.M. de.

    1979-01-01

    This work analyses the effect of the incorporation of a second column of extraction by solvents in pulsed plate columns in the Process of Uranium Purification. Operating with the aqueous phase of washing this second column of extraction recovers the dragged Uranium, increasing the efficiency of the process. The experiments were carried out in the display unit of Uranium purification in the Institute of Energetic and Nuclear Researches in Sao Paulo, where the dimension and the performance were studied with the following parameters: real increase in the efficiency and decontamination in the process. An efficiency superior to 98% in mass was obtained against 84,6% in the conventional process. With a performance similar to the first column of extract on the decontamination, about 99%, obtained in this column, maintained the grade of nuclear purity peculiar to the Process of Uranium Purification by solvents in pulsed plate columns. (author) [pt

  9. Pathways of cellular internalisation of liposomes delivered siRNA and effects on siRNA engagement with target mRNA and silencing in cancer cells.

    Science.gov (United States)

    Alshehri, Abdullah; Grabowska, Anna; Stolnik, Snow

    2018-02-28

    Design of an efficient delivery system is a generally recognised bottleneck in translation of siRNA technology into clinic. Despite research efforts, cellular processes that determine efficiency of siRNA silencing achieved by different delivery formulations remain unclear. Here, we investigated the mechanism(s) of cellular internalisation of a model siRNA-loaded liposome system in a correlation to the engagement of delivered siRNA with its target and consequent silencing by adopting siRNA molecular beacon technology. Probing of cellular internalisation pathways by a panel of pharmacological inhibitors indicated that clathrin-mediated (dynamin-dependent) endocytosis, macropinocytosis (dynamine independent), and cell membrane cholesterol dependent process(es) (clathrin and caveolea-independent) all play a role in the siRNA-liposomes internalization. The inhibition of either of these entry routes was, in general, mirrored by a reduction in the level of siRNA engagement with its target mRNA, as well as in a reduction of the target gene silencing. A dramatic increase in siRNA engagement with its target RNA was observed on disruption of endosomal membrane (by chloroquine), accompanied with an increased silencing. The work thus illustrates that employing molecular beacon siRNA technology one can start to assess the target RNA engagement - a stage between initial cellular internalization and final gene silencing of siRNA delivery systems.

  10. A novel multimodal chromatography based single step purification process for efficient manufacturing of an E. coli based biotherapeutic protein product.

    Science.gov (United States)

    Bhambure, Rahul; Gupta, Darpan; Rathore, Anurag S

    2013-11-01

    Methionine oxidized, reduced and fMet forms of a native recombinant protein product are often the critical product variants which are associated with proteins expressed as bacterial inclusion bodies in E. coli. Such product variants differ from native protein in their structural and functional aspects, and may lead to loss of biological activity and immunogenic response in patients. This investigation focuses on evaluation of multimodal chromatography for selective removal of these product variants using recombinant human granulocyte colony stimulating factor (GCSF) as the model protein. Unique selectivity in separation of closely related product variants was obtained using combined pH and salt based elution gradients in hydrophobic charge induction chromatography. Simultaneous removal of process related impurities was also achieved in flow-through leading to single step purification process for the GCSF. Results indicate that the product recovery of up to 90.0% can be obtained with purity levels of greater than 99.0%. Binding the target protein at pHproduct variants using the combined pH and salt based elution gradient and removal of the host cell impurities in flow-through are the key novel features of the developed multimodal chromatographic purification step. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Impurity impacts on the purification process in oxy-fuel combustion based CO2 capture and storage system

    International Nuclear Information System (INIS)

    Li, H.; Yan, J.; Yan, J.; Anheden, M.

    2009-01-01

    Based on the requirements of CO 2 transportation and storage, non-condensable gases, such as O 2 , N 2 and Ar should be removed from the CO 2 -stream captured from an oxy-fuel combustion process. For a purification process, impurities have great impacts on the design, operation and optimization through their impacts on the thermodynamic properties of CO 2 -streams. Study results show that the increments of impurities will make the energy consumption of purification increase; and make CO 2 purity of separation product and CO 2 recovery rate decrease. In addition, under the same operating conditions, energy consumptions have different sensitivities to the variation of the impurity mole fraction of feed fluids. The isothermal compression work is more sensitive to the variation of SO 2 ; while the isentropic compression work is more sensitive to the variation of Ar. In the flash system, the energy consumption of condensation in is more sensitive to the variation of Ar; but in the distillation system, the energy consumption of condensation is more sensitive to the variation of SO 2 , and CO 2 purity of separation is more sensitive to the variation of SO 2 . (author)

  12. Process development, design and operation of off-line purification system for oil-contaminated impure heavy water

    International Nuclear Information System (INIS)

    Bose, H.; Rakesh Kumar; Gandhi, H.C.; Unny, V.K.P.; Ghosh, S.K.; Mishra, Vivek; Shukla, D.K.; Duraisamy, S.; Agarwal, S.K.

    2004-01-01

    A large volume of degraded, tritiated heavy water contaminated with mineral oil and ionic impurities have accumulated at Dhruva in the past years of reactor operation as a result of routine operation and maintenance activities. The need was felt for a simple and efficient process that could be set up and operated locally at site using readily available materials, to purify the accumulated impure heavy waters at Dhruva so as to make them acceptable at the up gradation facilities. After a detailed laboratory study, a three stage clean-up process was developed which could purify a highly turbid oil-water emulsion to yield clear, oil-free and de-mineralized heavy water at reasonable rates of volume through-put. Based on the laboratory data, a suitably scaled up purification unit has been designed and commissioned which in the past few months has processed a sizeable volume of oil-contaminated heavy water waste from Dhruva, with most satisfactory results

  13. Microfluidic cartridges for DNA purification and genotyping processed in standard laboratory instruments

    Science.gov (United States)

    Focke, Maximilian; Mark, Daniel; Stumpf, Fabian; Müller, Martina; Roth, Günter; Zengerle, Roland; von Stetten, Felix

    2011-06-01

    Two microfluidic cartridges intended for upgrading standard laboratory instruments with automated liquid handling capability by use of centrifugal forces are presented. The first microfluidic cartridge enables purification of DNA from human whole blood and is operated in a standard laboratory centrifuge. The second microfluidic catridge enables genotyping of pathogens by geometrically multiplexed real-time PCR. It is operated in a slightly modified off-the-shelf thermal cycler. Both solutions aim at smart and cost-efficient ways to automate work flows in laboratories. The DNA purification cartridge automates all liquid handling steps starting from a lysed blood sample to PCR ready DNA. The cartridge contains two manually crushable glass ampoules with liquid reagents. The DNA yield extracted from a 32 μl blood sample is 192 +/- 30 ng which corresponds to 53 +/- 8% of a reference extraction. The genotyping cartridge is applied to analyse isolates of the multi-resistant Staphyloccus aureus (MRSA) by real-time PCR. The wells contain pre-stored dry reagents such as primers and probes. Evaluation of the system with 44 genotyping assays showed a 100% specificity and agreement with the reference assays in standard tubes. The lower limit of detection was well below 10 copies of DNA per reaction.

  14. Purification processes of cadmium based quantum dots in aqueous medium: a comparative study

    Science.gov (United States)

    Petris, Dimitri; Freitas, Denilson V.; dos Santos, Rayany K. V.; Dias, Jéssica M. M.; Navarro, Marcelo

    2017-07-01

    Three different purification methods for CdTe-MPA quantum dot (QD) were performed in aqueous medium: acid titration (HCl, HClO4, H2SO4 and CH3COOH), non-selective precipitation by addition of acetone and co-precipitation of the QD in the presence of inorganic salts. The QD stock solutions were prepared by an electrochemical method of synthesis, in four different heating times (1 h, 4 h, 8 h and 12 h). After purifications, the QD solids were redispersed in distilled water and analyzed by absorption and emission spectra. The λ abs and λ em of the purified QDs showed similar data observed for QD stock solutions, and the recovery rate varied from 71% to 99%. Co-precipitation method showed some advantages: quantum yield maintenance of the QD redispersed solution, longer period of storage (over 6 months) in solution and in solid state (QD embedded into the KCl crystal lattice). CdSe-MPA and CdS-MPA solutions were also purified by co-precipitation method with KCl, showing good results as observed for CdTe-MPA.

  15. Chemical purification of Gunungpati elephant foot yam flour to improve physical and chemical quality on processed food

    Science.gov (United States)

    Paramita, Octavianti; Wahyuningsih, Ansori, Muhammad

    2017-03-01

    This study was aimed at improving the physicochemical quality of elephant foot yam flour in Gunungpati, Semarang by chemical purification. The utilization of elephant foot yam flour in several processed food was also discussed in this study. The flour purification discussed in this study was expected to become a reference for the manufacturers of elephant foot yam flour and its processed food in Gunungpati. This study modified the elephant foot yam flour using pre - gelatinization method. The physical and chemical quality of each elephant foot yam flour purification sample were assessed using proximate analysis. The likability test was conducted for its processed food. 20 grams of elephant foot yam flour was put into a beaker glass, then 60 ml of water was added. The suspension was then heated at a temperature of 60 ° C and 70 ° C while stirred until it was homogeneous and thickened for 10, 30 and 60 minutes. The flour which had been heated was then cooled at room temperature for 1 hour and then at a temperature of 0 ° C until it was frozen. Furthermore, flour was dried in an oven at a temperature of 60 ° C for 9 hours. The dried flour was sifted with a 80 mesh sieve. Chemical test was conducted after elephant foot yam was pre-gelatinized to determine changes in the quality flour: test levels of protein, fat, crude fiber content, moisture content, ash content and starch content. In addition, color tests and granular test on elephant foot yam flour were also conducted. The pre-gelatinization as chemical treatment on elephant foot yam flour in this study was able to change the functional properties of elephant foot yam flour towards a better processing characterized by a brighter color (L = 70, a = 6 and b = 12), the hydrolysis of polysaccharides flour into shorter chain (flour content decreased to 44%), the expansion of granules in elephant foot yam resulting in a process - ready flour, and better monolayer water content of 9%. The content of protein and fiber

  16. Validation of 68Ge/68Ga generator processing by chemical purification for routine clinical application of 68Ga-DOTATOC

    International Nuclear Information System (INIS)

    Asti, Mattia; De Pietri, Giovanni; Fraternali, Alessandro; Grassi, Elisa; Sghedoni, Roberto; Fioroni, Federica; Roesch, Frank; Versari, Annibale; Salvo, Diana

    2008-01-01

    Introduction: Imaging of somatostatin receptor expressing tumours has been greatly enhanced by the use of 68 Ga-DOTATOC and PET/CT. Methods: In this work, a purification method for the 68 Ge/ 68 Ga generator eluate and a method to produce 68 Ga-DOTATOC suitable for clinical use were evaluated. The generator eluate was purified and concentrated on a cation-exchange cartridge in HCl/acetone media. The efficacy of this procedure in eliminating metal impurities from the 68 Ga solution was investigated by ICP-MS. The radiotracer quality was evaluated by radio-TLC, GC and γ-ray spectrometry. Results: 68 Ga-DOTATOC preparations (n=33) were carried out with a mean synthesis yield of 59.3±2.8% (not corrected for decay) and a batch activity ranging from 555 to 296 MBq. The radiochemical and radionuclidic purity were >98% and 99.9999%, respectively. With this purification process, >95% of the Fe(III), Zn(II) and Mn(II) were eliminated from the solution. Conclusions: 68 Ga-DOTATOC produced with this method can be efficiently used in nuclear medicine departments for PET evaluations

  17. Novel immobilization process of a thermophilic catalase: efficient purification by heat treatment and subsequent immobilization at high temperature.

    Science.gov (United States)

    Xu, Juan; Luo, Hui; López, Claudia; Xiao, Jing; Chang, Yanhong

    2015-10-01

    The main goal of the present work is to investigate a novel process of purification and immobilization of a thermophilic catalase at high temperatures. The catalase, originated from Bacillus sp., was overexpressed in a recombinant Escherichia coli BL21(DE3)/pET28-CATHis and efficiently purified by heat treatment, achieving a threefold purification. The purified catalase was then immobilized onto an epoxy support at different temperatures (25, 40, and 55 °C). The immobilizate obtained at higher temperatures reached its maximum activity in a shorter time than that obtained at lower temperatures. Furthermore, immobilization at higher temperatures required a lower ionic strength than immobilization at lower temperatures. The characteristics of immobilized enzymes prepared at different temperatures were investigated. The high-temperature immobilizate (55 °C) showed the highest thermal stability, followed by the 40 °C immobilizate. And the high-temperature immobilizate (55 °C) had slightly higher operational stability than the 25 °C immobilizate. All of the immobilized catalase preparations showed higher stability than the free enzyme at alkaline pH 10.0, while the alkali resistance of the 25 °C immobilizate was slightly better than that of the 40 and 55 °C immobilizates.

  18. Self-packed filter plates: a good alternative for pre-packed filter plates for developing purification processes of therapeutic proteins

    NARCIS (Netherlands)

    Li, X.; Roo, de G.; Burgers, K.; Ottens, M.; Eppink, M.H.M.

    2012-01-01

    The use of high throughput screening (HTS) has successfully been applied in the past years in downstream process development of therapeutic proteins. Different HTS applications were introduced to speed up the purification process development of these proteins. In the light of these findings, studies

  19. APPLICATION OF PAN/PANI COMPOSITE MEMBRANES IN PURIFICATION OF INDUSTRIAL WASTEWATER GENERATED DURING PROCESSING OF METALS

    Directory of Open Access Journals (Sweden)

    Beata Fryczkowska

    2017-04-01

    Full Text Available The paper presents results of research on the use of composite membranes of polyacrylonitrile (PAN doped polyaniline (PANI to remove contaminations of industrial wastewater generated during the processing of metals. Wastewater obtained from industry was pre-treated with the flocculant Magnafloc®336, and then the supernatant solution was introduced into the ultrafiltration cell, AMICON (Millipore equipped in the previously prepared polymer membrane. Using spectrophotometer UV-Vis (HACH and atomic absorption spectrometry (AAS pollution indicators was marked before and after the integrated purification proces, to determine the degree of removal of selected ions from wastewater. As a result of flocculation from wastewater there have been removed phosphates (79%, chlorides (11-14%, sulfates (2-10% and iron (36-92%, cobalt (~ 80%, cadmium (~ 31% and nickel (~ 25%. However, the pressure membrane process almost completely removed zinc, copper and cadmium (~ 100%, iron (by a further 43-69% and phosphate anions, which was a little.

  20. Physicochemically modified peat by thermal and oxidation processes as an active material for purification of wastewaters from certain hazardous pollutants

    Directory of Open Access Journals (Sweden)

    Purenović Jelena M.

    2017-01-01

    Full Text Available The physicochemical modification of peat through thermal and oxidation processes was carried out, in order to obtain new, inexpensive and active material for purification of different types of waters. During the modification, surface chemical compounds of Shilov type were formed. Batch adsorption properties and suitability of physicochemically modified peat (PCMP for odor removal were tested in aqueous solutions of H2S and colloidal sulphur. Additionally, PCMP was tested in the removal of As(V which is hazardous ingredient in contaminated waters. Possible mechanisms of pollutants binding include interactions, which lead to formation of adducts and clathrates. All these processes are elucidated in detail. The results showed that the obtained material can be used for the removal of sulphide, colloidal sulphur and As(V from different types of waters. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 45012

  1. Theoretical analysis of a biogas-fed PEMFC system with different hydrogen purifications: Conventional and membrane-based water gas shift processes

    International Nuclear Information System (INIS)

    Authayanun, Suthida; Aunsup, Pounyaporn; Patcharavorachot, Yaneeporn; Arpornwichanop, Amornchai

    2014-01-01

    Highlights: • Thermodynamic analysis of the biogas-fed PEMFC system is performed. • Conventional and membrane-based WGS processes for H 2 purification are studied. • A flowsheet model of the PEMFC system is developed. • Effect of key parameters on yields of H 2 and carbon in the biogas reformer is shown. • Performance of PEMFC systems with different H 2 purification processes is analyzed. - Abstract: This study presents a thermodynamic analysis of biogas reforming and proton electrolyte membrane fuel cell (PEMFC) integrated process with different hydrogen purifications: conventional and membrane-based water gas shift processes. The aim is to determine the optimal reforming process for hydrogen production from biogas in the PEMFC system. The formation of carbon is concerned in the hydrogen production. The simulation results show that increases in the steam-to-methane ratio and reformer temperature can improve the hydrogen yield and reduce the carbon formation. From the performance analysis, it is found that when the PEMFC is operated at high temperature and fuel utilization, the overall system efficiency enhances. The performance of the PEMFC system with the installation of a water gas shift membrane unit in the hydrogen purification step is slightly increased, compared with a conventional process

  2. Effect of water purification process in radioactive content: analysis on small scale purification plants; Efecto del proceso de purificacion de agua en el contenido radiactivo: analisis en plantas purificadoras a pequena escala

    Energy Technology Data Exchange (ETDEWEB)

    Lopez del Rio, H.; Quiroga S, J. C.; Davila R, J. I.; Mireles G, F. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98000, Zacatecas (Mexico)], e-mail: hlopez@uaz.edu.mx

    2009-10-15

    Water from small scale purification plants is a low cost alternative for consumers in comparison to the bottled commercial presentations. Because of its low cost per liter, the consumption of this product has increased in recent years, stimulating in turn the installation of purification systems for these small businesses. The purpose of this study was to estimate the efficiency of small scale purification systems located in the cities of Zacatecas and Guadalupe, Zacatecas, to reduce the radioactive content of water. It was measured the total alpha and beta activity in water samples of entry and exit to process, through the liquid scintillation technique. In general it was observed that the process is more efficient in removing alpha that beta activity. The fraction of total alpha activity removed varied between 27 and 100%, while between 0 and 77% of the total beta activity was removed by the analyzed plants. In all cases, the total radioactivity level was lower than the maximum permissible value settled by the official mexican standard for drinking water. (Author)

  3. APPLICATION OF MEMBRANES FROM POLYACRYLONITRITE DOPPED WITH GRAPHEN OXIDE IN PURIFICATION OF INDUSTRIAL WASTEWATER GENERATED DURING PROCESSING OF METALS

    Directory of Open Access Journals (Sweden)

    Tomasz Turek

    2017-08-01

    Full Text Available The paper presents results of research on the use of composite membranes of polyacrylonitrile (PAN doped with graphene oxide (GO to remove contaminations of galvanic wastewater. Membranes were obtained using phase inversion method from PAN and GO solution in N,N-dimethylformamide (DMF. Wastewater was pre-treated with the flocculant Magnafloc®336. Next, ultrafiltration of the treated wastewater was carried out in the ultrafiltration cell AMICON on the previously prepared PAN/GO composite membranes. Physico-chemical properties and composition of solutions before and after integrated purification process were analyzed by UV-Vis spectrophotometer and atomic absorption spectrometry (AAS. As a result of flocculation from wastewater there have been removed phosphates (97%, chlorides (5,2%, sulfates (5,9% and iron (82%. In addition, as a result of ultrafiltration was complete removal of phosphate anions (100% and iron (~91-92%, zinc (68÷84%, lead (65-98% and cadmium (~67%.

  4. Energy-neutral sustainable nutrient recovery incorporated with the wastewater purification process in an enlarged microbial nutrient recovery cell

    Science.gov (United States)

    Sun, Dongya; Gao, Yifan; Hou, Dianxun; Zuo, Kuichang; Chen, Xi; Liang, Peng; Zhang, Xiaoyuan; Ren, Zhiyong Jason; Huang, Xia

    2018-04-01

    Recovery of nutrient resources from the wastewater is now an inevitable strategy to maintain the supply of both nutrient and water for our huge population. While the intensive energy consumption in conventional nutrient recovery technologies still remained as the bottleneck towards the sustainable nutrient recycle. This study proposed an enlarged microbial nutrient recovery cell (EMNRC) which was powered by the energy contained in wastewater and achieved multi-cycle nutrient recovery incorporated with in situ wastewater treatment. With the optimal recovery solution of 3 g/L NaCl and the optimal volume ratio of wastewater to recovery solution of 10:1, >89% of phosphorus and >62% of ammonium nitrogen were recovered into struvite. An extremely low water input ratio of water. It was proved the EMNRC system was a promising technology which could utilize the chemical energy contained in wastewater itself and energy-neutrally recover nutrient during the continuous wastewater purification process.

  5. Improved purification process of β- and α-trypsin isoforms by ion-exchange chromatography

    Directory of Open Access Journals (Sweden)

    Alexandre Martins Costa Santos

    2008-08-01

    Full Text Available The purpose of this work was to improve the separation and yield of pure β- and α-trypsin isoforms by ion-exchange chromatography and to characterize some physical-chemical properties of these isoforms. Purification of trypsin isoforms was performed by ion-exchange chromatography in 0.1 mol/L tris-HC buffer, pH 7.10 at 4ºC. The sample loading, salt concentration, flow rate and pH of mobile phase were varied to determine their effects on the resolution of the separation. The resolution was optimized mainly between β- and α-trypsin. Pure isoforms were obtained by chromatographying 100 mg of commercial trypsin during seven days, yielding 51 mg of high purity β-trypsin and 13 mg of α-trypsin partially pure, with small amounts of contaminating of ψ-trypsin. Thus, time and resolution of purification were optimized yielding large amounts of pure active enzymes that are useful for several research areas and biotechnology.O propósito deste trabalho foi melhorar a separação e o rendimento das isoformas puras β- e α-tripsina por meio de cromatografia de troca iônica e caracterizar algumas propriedades físico-químicas dessas isoformas. A purificação de isoformas de tripsina foi realizada em SE Sephadex, com tampão tris-HCl, pH 7,10 a 4ºC. A quantidade de amostra, a concentração salina, o fluxo e o pH da fase móvel foram variados para determinar o efeito sobre a resolução da separação. A resolução foi otimizada principalmente entre β- e α-tripsina, utilizando o pH 7,10 a 4ºC. Isoformas puras foram obtidas a partir de 100 mg de tripsina comercial bovina depois de sete dias de cromatografia, fornecendo 51,0 mg de β-tripsina totalmente pura e 13,0 mg de α-tripsina parcialmente pura, com quantidades pequenas de contaminação por ψ-Tripsina. Assim, tempo e resolução da purificação foram otimizados redendo grandes quantidades de enzimas puras e ativas que são úteis em várias áreas de pesquisa e ciências biotecnológicas.

  6. Monitoring the process of purification of crude glycerol derived from biodiesel production: a method based on fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Keurison F.; Caires, Anderson R.L. [Universidade Federal da Grande Dourados, MS (Brazil). Grupo de Optica Aplicada; Oliveira, Samuel L. [Universidade Federal de Mato Grosso do Sul (UFMS), MS (Brazil). Grupo de Optica e Fotonica

    2011-07-01

    Full text. The use of biodiesel has increased worldwide. The biodiesel production on an industrial scale has been based on the transesterification of vegetable oils and fats with methanol in the presence of an alkaline catalyst. During the transesterification, one molecule of triglyceride reacts with three molecules of alcohol to produce glycerol and molecules of alkyl esters (biodiesel). As a result, an increase in biodiesel production also enhances the availability of glycerol on the market. However, crude glycerin has about 30% of impurities which are inherent to biodiesel production such as catalyst, alcohol and fatty acids. The present study evaluated the usefulness of the fluorescence spectroscopy as a tool to monitor the glycerol purification process. Glycerol samples were obtained from transesterification of soybean, canola, and sunflower oils in the presence of NaOH. After stirring time, the solutions were let to stand in separating funnels, then two phases were observed: one containing mainly biodiesel and other consisting of glycol. Then, the respective glycerol samples were collected, henceforth called G1. After that, it was added H2SO4 (20%) in the crude glycerol samples to reduce their pH to 4 in order to remove fatty acids. The solutions were stored for 24 hours in separating funnels. The glycerol (heavy phase), hereafter named G2, was then separated and filtered. To remove other impurities from G2 samples by means of ionic exchange columns, the samples were neutralized and diluted using Milli-Q water (G3 samples). Aliquots of 20 mL were then passed through cationic and anionic resins (G4 and G5 samples, respectively). Emission and excitation spectra of the G1-G5 samples as well as of the glycerol PA-ACS (reference) were recorded at room temperature using a spectrofluorimeter. The emission spectra were obtained setting the excitation at 325nm and monitoring the emission in the 330-800nm range. Fluorimetric maps were also achieved by pumping the

  7. Sulfur hexafluoride purification from mixtures with air: a process feasibility study

    International Nuclear Information System (INIS)

    Perona, J.J.; Watson, J.S.

    1979-10-01

    Studies were made of the purification of SF 6 vapor contaminated with air for application at the Holifield Heavy-Ion Research Facility. Liquefaction appears to be a good method for recovering about 90% of the SF 6 if it is badly contaminated (15% air), and an even greater fraction can be recovered from mixtures containing less air. In cases where liquefaction is insufficient by itself, adsorption of SF 6 on activated carbon at -50 0 F is promising. Two carbon beds, each containing about 500 lb of carbon, should be sufficient. The refrigeration system for liquefaction and adsorption would have a capacity of about 2 tons. As an alternative, the use of molecular sieves to trap out the air was investigated, but such a bed would require at least 15,000 lb of molecular sieves and very long cycle times. A large-scale desublimer was also investigated and appears workable, but it would require some development effort before the design could proceed with confidence

  8. Intranasal delivery of antiviral siRNA.

    Science.gov (United States)

    Barik, Sailen

    2011-01-01

    Intranasal administration of synthetic siRNA is an effective modality of RNAi delivery for the prevention and therapy of respiratory diseases, including pulmonary infections. Vehicles used for nasal siRNA delivery include established as well as novel reagents, many of which have been recently optimized. In general, they all promote significant uptake of siRNA into the lower respiratory tract, including the lung. When properly designed and optimized, these siRNAs offer significant protection against respiratory viruses such as influenza virus, parainfluenza virus and respiratory syncytial virus (RSV). Nasally administered siRNA remains within the lung and does not access systemic blood flow, as judged by its absence in other major organs such as liver, heart, kidney, and skeletal muscle. Adverse immune reaction is generally not encountered, especially when immunogenic and/or off-target siRNA sequences and toxic vehicles are avoided. In fact, siRNA against RSV has entered Phase II clinical trials in human with promising results. Here, we provide a standardized procedure for using the nose as a specific route for siRNA delivery into the lung of laboratory animals. It should be clear that this simple and efficient system has enormous potential for therapeutics.

  9. A review: Potential and challenges of biologically activated carbon to remove natural organic matter in drinking water purification process.

    Science.gov (United States)

    Korotta-Gamage, Shashika Madushi; Sathasivan, Arumugam

    2017-01-01

    The use of biologically activated carbon (BAC) in drinking water purification is reviewed. In the past BAC is seen mostly as a polishing treatment. However, BAC has the potential to provide solution to recent challenges faced by water utilities arising from change in natural organic matter (NOM) composition in drinking water sources - increased NOM concentration with a larger fraction of hydrophilic compounds and ever increasing trace level organic pollutants. Hydrophilic NOM is not removed by traditional coagulation process and causes bacterial regrowth and increases disinfection by-products (DBPs) formation during disinfection. BAC can offer many advantages by removing hydrophilic fraction and many toxic and endocrine compounds which are not otherwise removed. BAC can also aid the other downstream processes if used as a pre-treatment. Major drawback of BAC was longer empty bed contact time (EBCT) required for an effective NOM removal. This critical review analyses the strategies that have been adopted to enhance the biological activity of the carbon by operational means and summarises the surface modification methods. To maximize the benefit of the BAC, a rethink of current treatment plant configuration is proposed. If the process can be expedited and adopted appropriately, BAC can solve many of the current problems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Studies on molybdenum elution study in dowex 1x8 resin applied on purification process of fission 99Mo

    International Nuclear Information System (INIS)

    Damasceno, M.O.; Yamaura, M.; Santos, J.L. dos; Forbicini, C.A.L.G. de O.

    2013-01-01

    Molybdenum-99 is the most widely employed radioisotope in nuclear medicine, due to its decay product, Technetium-99, which is used in radio-pharmaceutical marking molecules for diagnostic examinations tumor dis-eases. Today Brazil imports 99 Mo from some countries, so the National Commission of Nuclear Energy (CNEN) is implementing a new research reactor RMB, currently in the conceptual design phase. The process of separation of fission 99 Mo begins with the dissolution of uranium targets after irradiation in reactor; the resulting solution goes through a series of chromatographic columns that allows a gradual decontamination of other components, yielding the 99 Mo with high radio-chemical and chemical purity for use in nuclear medicine as a generator of 99 mTc. This work is part of the RMB research project to separate and purify the fission 99 Mo by chromatographic columns from alkaline dissolution of LEU UAl x -Al targets. In the present study Mo removal by batch assays and glass column was investigated using anionic exchanger Dowex 1x8. Different salts and its concentration, cations and temperature were evaluated on elution of molybdenum and iodine (contaminant) retained on resin Dowex 1x8, aiming at their use in the process of separation and purification in chromatography columns on Brazilian project. Results showed high recovery of Mo and low-level contamination by iodine using NaHCO 3 hot solution. (author)

  11. Sucrose purification and repeated ethanol production from sugars remaining in sweet sorghum juice subjected to a membrane separation process.

    Science.gov (United States)

    Sasaki, Kengo; Tsuge, Yota; Kawaguchi, Hideo; Yasukawa, Masahiro; Sasaki, Daisuke; Sazuka, Takashi; Kamio, Eiji; Ogino, Chiaki; Matsuyama, Hideto; Kondo, Akihiko

    2017-08-01

    The juice from sweet sorghum cultivar SIL-05 (harvested at physiological maturity) was extracted, and the component sucrose and reducing sugars (such as glucose and fructose) were subjected to a membrane separation process to purify the sucrose for subsequent sugar refining and to obtain a feedstock for repeated bioethanol production. Nanofiltration (NF) of an ultrafiltration (UF) permeate using an NTR-7450 membrane (Nitto Denko Corporation, Osaka, Japan) concentrated the juice and produced a sucrose-rich fraction (143.2 g L -1 sucrose, 8.5 g L -1 glucose, and 4.5 g L -1 fructose). In addition, the above NF permeate was concentrated using an ESNA3 NF membrane to provide concentrated permeated sugars (227.9 g L -1 ) and capture various amino acids in the juice, enabling subsequent ethanol fermentation without the addition of an exogenous nitrogen source. Sequential batch fermentation using the ESNA3 membrane concentrate provided an ethanol titer and theoretical ethanol yield of 102.5-109.5 g L -1 and 84.4-89.6%, respectively, throughout the five-cycle batch fermentation by Saccharomyces cerevisiae BY4741. Our results demonstrate that a membrane process using UF and two types of NF membranes has the potential to allow sucrose purification and repeated bioethanol production.

  12. siRNA and innate immunity.

    Science.gov (United States)

    Robbins, Marjorie; Judge, Adam; MacLachlan, Ian

    2009-06-01

    Canonical small interfering RNA (siRNA) duplexes are potent activators of the mammalian innate immune system. The induction of innate immunity by siRNA is dependent on siRNA structure and sequence, method of delivery, and cell type. Synthetic siRNA in delivery vehicles that facilitate cellular uptake can induce high levels of inflammatory cytokines and interferons after systemic administration in mammals and in primary human blood cell cultures. This activation is predominantly mediated by immune cells, normally via a Toll-like receptor (TLR) pathway. The siRNA sequence dependency of these pathways varies with the type and location of the TLR involved. Alternatively nonimmune cell activation may also occur, typically resulting from siRNA interaction with cytoplasmic RNA sensors such as RIG1. As immune activation by siRNA-based drugs represents an undesirable side effect due to the considerable toxicities associated with excessive cytokine release in humans, understanding and abrogating this activity will be a critical component in the development of safe and effective therapeutics. This review describes the intracellular mechanisms of innate immune activation by siRNA, the design of appropriate sequences and chemical modification approaches, and suitable experimental methods for studying their effects, with a view toward reducing siRNA-mediated off-target effects.

  13. Model-based Rational and Systematic Protein Purification Process Development : A Knowledge-based Approach

    NARCIS (Netherlands)

    Kungah Nfor, B.

    2011-01-01

    The increasing market and regulatory (quality and safety) demands on therapeutic proteins calls for radical improvement in their manufacturing processes. Addressing these challenges requires the adoption of strategies and tools that enable faster and more efficient process development. This thesis

  14. Water purification in Borexino

    Energy Technology Data Exchange (ETDEWEB)

    Giammarchi, M. [Infn Milano (Italy); Balata, M.; Ioannucci, L.; Nisi, S. [Laboratori Nazionali del Gran Sasso (Italy); Goretti, A.; Ianni, A. [Princeton University (United States); Miramonti, L. [Dip. di Fisica dell' Università di Milano e Infn (Italy)

    2013-08-08

    Astroparticle Physics and Underground experiments searching for rare nuclear events, need high purity materials to act as detectors or detector shielding. Water has the advantage of being cheap, dense and easily available. Most of all, water can be purified to the goal of obatining a high level of radiopurity. Water Purification can be achieved by means of a combination of processes, including filtration, reverse osmosis, deionization and gas stripping. The Water Purification System for the Borexino experiment, will be described together with its main performances.

  15. Purification of a modified cyclosporine A by co-current centrifugal partition chromatography: process development and intensification.

    Science.gov (United States)

    Amarouche, Nassima; Boudesocque, Leslie; Sayagh, Charlotte; Giraud, Matthieu; McGarrity, John; Butte, Alessandro; Marchal, Luc; Foucault, Alain; Renault, Jean-Hugues

    2013-10-11

    Synthetic hydrophobic non-ionizable peptides are not soluble in most common solvents and are thus difficult to purify by preparative reversed-phase HPLC, normally used for industrial production. The challenge exists to develop alternative purification chromatographic processes using suitable solvents and providing good yields, high purity and sufficient productivity. A 11mer hydrophobic synthetic modified cyclosporine, showing an anti-HIV activity, was successfully purified by centrifugal partition chromatography using the biphasic solvent system heptane/ethyl acetate/acetone/methanol/water (1:2:2:1:2, v/v). A 5% co-current elution - made possible by the liquid nature of the two phases - has been used in order to avoid hydrodynamic instabilities mainly due to the physico-chemical properties of the target peptide. This original solution was developed after the study of the effect of the peptide on the hydrodynamic behavior of the two phases during the separation, and the visualization of the flow patterns using the Visual-CPC device. Critical impurities were efficiently eliminated and the peptide was recovered in high yield and high productivity achieving the specifications requirements. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Optimum operating conditions for a water purification process integrated to a heat transformer with energy recycling using neural network inverse

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, J.A.; Siqueiros, J.; Juarez-Romero, D. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos (UAEM), Av. Universidad No. 1001, Col. Chamilpa, Cuernavaca, Morelos C.P. 62209 (Mexico); Bassam, A. [Posgrado en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos (UAEM), Av. Universidad No. 1001, Col. Chamilpa, Cuernavaca, Morelos C.P. 62209 (Mexico)

    2009-04-15

    Artificial neural network inverse (ANNi) is applied to calculate the optimal operating conditions on the coefficient of performance (COP) for a water purification process integrated to an absorption heat transformer with energy recycling. An artificial neural network (ANN) model is developed to predict the COP which was increased with energy recycling. This ANN model takes into account the input and output temperatures for each one of the four components (absorber, generator, evaporator, and condenser), as well as two pressures and LiBr + H{sub 2}O concentrations. For the network, a feedforward with one hidden layer, a Levenberg-Marquardt learning algorithm, a hyperbolic tangent sigmoid transfer function and a linear transfer function were used. The best fitting training data set was obtained with three neurons in the hidden layer. On the validation data set, simulations and experimental data test were in good agreement (R > 0.99). This ANN model can be used to predict the COP when the input variables (operating conditions) are well known. However, to control the COP in the system, we developed a strategy to estimate the optimal input variables when a COP is required from ANNi. An optimization method (the Nelder-Mead simplex method) is used to fit the unknown input variable resulted from the ANNi. This methodology can be applied to control on-line the performance of the system. (author)

  17. Molybdenum adsorption by alumina and Dowex 1x8 resin for the separation and purification process of fission 99Mo

    International Nuclear Information System (INIS)

    Yamaura, M.; Damasceno, M.O.; Freitas, A.A.; Camilo, R.L.; Araujo, I.C.; Forbicini, C.A.L.G. de O.

    2011-01-01

    Molybdenum-99 is the most widely employed radioisotope in nuclear medicine, due to its decay product, Technetium-99m, a radioisotope used in over 80% of diagnostic tests. Since 2009, the production of generators 99 Mo/ 99m Tc suffers a crisis of global supply. The raw material, the 99 Mo, is produced mainly by fission of 235 U in the reactor in uranium targets. Brazilian government invests in building of a research reactor suitable for the domestic production of 99 Mo from LEU (Low Enriched Uranium) targets and the IPEN/CNEN develops the production technology. This work is part of the research for the development of production technology of 99 Mo at the IPEN/CNEN-SP. The study has evaluated the adsorption behaviour of molybdenum from the alkaline dissolution of aluminum plates by the alumina and by the anionic resin Dowex 1x8 aiming at their use in the process of separation and purification in chromatography columns. Influences of pH and of aluminum concentration in the retention of molybdenum were investigated. Results showed high performance in the wide pH range. However in strongly acid solutions containing aluminum, alumina showed higher adsorption percentage than that achieved by the resin Dowex 1x8. (author)

  18. Removal of cationic pollutants from water by xanthated corn cob: optimization, kinetics, thermodynamics, and prediction of purification process.

    Science.gov (United States)

    Kostić, Miloš; Đorđević, Miloš; Mitrović, Jelena; Velinov, Nena; Bojić, Danijela; Antonijević, Milan; Bojić, Aleksandar

    2017-07-01

    The removal of Cr(III) ions and methylene blue (MB) from aqueous solutions by xanthated corn cob (xCC) in batch conditions was investigated. The sorption capacity of xCC strongly depended of the pH, and increase when the pH rises. The kinetics was well fitted by pseudo-second-order and Chrastil's model. Sorption of Cr(III) ions and MB on xCC was rapid during the first 20 min of contact time and, thereafter, the biosorption rate decrease gradually until reaching equilibrium. The maximum sorption capacity of 17.13 and 83.89 mg g -1 for Cr(III) ions and MB, respectively, was obtained at 40 °C, pH 5, and sorbent dose 4 g dm -3 for removal of Cr(III) ions and 1 g dm -3 for removal of MB. The prediction of purification process was successfully carried out, and the verification of theoretically calculated amounts of sorbent was confirmed by using packed-bed column laboratory system with recirculation of the aqueous phase. The wastewater from chrome plating industry was successfully purified, i.e., after 40 min concentration of Cr(III) ions was decreased lower than 0.1 mg dm -3 . Also, removal of MB from the river water was successfully carried out and after 40 min, removal efficiency was about 94%.

  19. EVALUATION OF THE POLYAD FB AIR PURIFICATION AND SOLVENT RECOVERY PROCESS FOR STYRENE REMOVAL

    Science.gov (United States)

    The report gives results of a study evaluating the Polyad fluidized-bed (FB) process for controlling styrene emissions at a representative fiberglass shower stall and bath tub manufacturing plan*t. he process was evaluated using a transport able unit supplied by Weatherly, Inc., ...

  20. Electron beam silicon purification

    Energy Technology Data Exchange (ETDEWEB)

    Kravtsov, Anatoly [SIA ' ' KEPP EU' ' , Riga (Latvia); Kravtsov, Alexey [' ' KEPP-service' ' Ltd., Moscow (Russian Federation)

    2014-11-15

    Purification of heavily doped electronic grade silicon by evaporation of N-type impurities with electron beam heating was investigated in process with a batch weight up to 50 kilos. Effective temperature of the melt, an indicative parameter suitable for purification process characterization was calculated and appeared to be stable for different load weight processes. Purified material was successfully approbated in standard CZ processes of three different companies. Each company used its standard process and obtained CZ monocrystals applicable for photovoltaic application. These facts enable process to be successfully scaled up to commercial volumes (150-300 kg) and yield solar grade silicon. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Separation and purification of 99Mo from uranium and fission products using Cintichem process, our experience

    International Nuclear Information System (INIS)

    Manolkar, R.B.; Mathakar, A.R.; Kumar, Yogendra; Kumar, Manoj; Dash, A.; Venkatesh, Meera; Pillai, K.T.; Singh, Sarbjit; Venugopal, V.

    2009-01-01

    A pilot study was carried out to assess the feasibility of producing 99 Mo by fission of Unat following the Cintichem method. U-Mo alloy was irradiated for one week at Dhruva reactor and processed for the separation of 99 Mo from fission products. The irradiated targets were chemically processed to separate and purify the 99 Mo. Recovery of ∼70% and the purity of 99 Mo was > 99%. (author)

  2. Electron beam induced purification of dilute off gases from industrial processes and automobile tunnels

    International Nuclear Information System (INIS)

    Paur, H.-R.; Maetzing, H.

    1993-01-01

    The electron beam process has proved to be an efficient method for the removal of inorganic pollutants from flue gas. Since it simulates natural processes which occur in the atmospheric photochemistry, it appeared attractive to investigate the potential of the e-beam process to clean off-gases which contain hydrocarbon and inorganic trace components. Such emissions arise from industrial processes and from automobile tunnels. Commercial solvents were vaporized in air and irradiated with energetic electrons (300 keV). CO, CO 2 and aerosol particles were found as products and were determined quantitatively. The aerosol particles can be collected by a gravel bed filter and can be removed by combustion or biological degradation. From experiments and model calculations it was found that the e-beam process is a very economic tool to remove hydrocarbons from large off-gas volumes at initial concentrations of 50-100 mg C/m 3 , and that NO x can be removed very efficiently from tunnel off-gas. (author)

  3. Recovery and purification of ethylene

    Science.gov (United States)

    Reyneke, Rian [Katy, TX; Foral, Michael J [Aurora, IL; Lee, Guang-Chung [Houston, TX; Eng, Wayne W. Y. [League City, TX; Sinclair, Iain [Warrington, GB; Lodgson, Jeffery S [Naperville, IL

    2008-10-21

    A process for the recovery and purification of ethylene and optionally propylene from a stream containing lighter and heavier components that employs an ethylene distributor column and a partially thermally coupled distributed distillation system.

  4. Purification process for aqueous solutions of rare earths by liquid-liquid extraction

    International Nuclear Information System (INIS)

    Rollat, A.; Sabot, J.L.; Burgard, M.; Delloye, T.

    1986-01-01

    Alkaline earth metals are removed by liquid-liquid extraction between on aqueous nitric phase of impure rare earth compounds and an organic phase of polyether (crown ether). This process is particularly suited to removal of Ca, Ba and Ra contained in nitric solutions of rare earths [fr

  5. Application of a multiwalled carbon nanotube-chitosan composite as an electrode in the electrosorption process for water purification.

    Science.gov (United States)

    Ma, Chih-Yu; Huang, Shih-Ching; Chou, Pei-Hsin; Den, Walter; Hou, Chia-Hung

    2016-03-01

    In this study, a multiwalled carbon nanotubes-chitosan (CNTs-CS) composite electrode was fabricated to enable water purification by electrosorption. The CNTs-CS composite electrode was shown to possess excellent capacitive behaviors and good pore accessibility by electrochemical impedance spectroscopy, galvanostatic charge-discharge, and cyclic voltammetry measurements in 1 M H2SO4 electrolyte. Moreover, the CNTs-CS composite electrode showed promising performance for capacitive water desalination. At an electric potential of 1.2 V, the electrosorption capacity and electrosorption rate of NaCl ions on the CNTs-CS composite electrode were determined to be 10.7 mg g(-1) and 0.051 min(-1), respectively, which were considerably higher than those of conventional activated electrodes. The improved electrosorption performance could be ascribed to the existence of mesopores. Additionally, the feasibility of electrosorptive removal of aniline from an aqueous solution has been demonstrated. Upon polarization at 0.6 V, the CNTs-CS composite electrode had a larger electrosorption capacity of 26.4 mg g(-1) and a higher electrosorption rate of 0.006 min(-1) for aniline compared with the open circuit condition. The enhanced adsorption resulted from the improved affinity between aniline and the electrode under electrochemical assistance involving a nonfaradic process. Consequently, the CNT-CS composite electrode, exhibiting typical double-layer capacitor behavior and a sufficient potential range, can be a potential electrode material for application in the electrosorption process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. A high recovery membrane process for purification of low-level radioactive liquid waste

    Energy Technology Data Exchange (ETDEWEB)

    Al-Samadi, R. [Ontario Power Generation, Pickering, Ontario (Canada); Davloor, R.; Harper, B., E-mail: ram.davloor@brucepower.com [Bruce Power, Tiverton, Ontario (Canada)

    2013-07-01

    An advanced Active Liquid Waste Treatment System (ALWTS) was designed placed in-service at the Bruce Nuclear Generating Station 'A' in 1999. As part of this unique system an innovative high recovery reverse osmosis system (ROS) was installed to concentrate the contaminants into a small retentate stream that can be processed on-site or sent off-site for disposal. The permeate is discharged to the lake. The overall permeate recovery of the system is greater than 98%. This patented system which saw its first commercial application at the station has now operated continuously for over thirteen years. It has enabled the ALWTS to consistently produce high quality effluent that exceeds environmental discharge limits. This paper discusses the high recovery membrane process its unique design features aimed at minimizing the volume of rejects its separation performance operating history. (author)

  7. Evaluation of Effectiveness Technological Process of Water Purification Exemplified on Modernized Water Treatment Plant at Otoczna

    Directory of Open Access Journals (Sweden)

    Jordanowska Joanna

    2014-12-01

    Full Text Available The article presents the work of the Water Treatment Plant in the town of Otoczna, located in the Wielkopolska province, before and after the modernization of the technological line. It includes the quality characteristics of the raw water and treated water with particular emphasis on changes in the quality indicators in the period 2002 -2012 in relation to the physicochemical parameters: the content of total iron and total manganese, the ammonium ion as well as organoleptic parameters(colour and turbidity. The efficiency of technological processes was analysed, including the processes of bed start up with chalcedonic sand to remove total iron and manganese and ammonium ion. Based on the survey, it was found that the applied modernization helped solve the problem of water quality, especially the removal of excessive concentrations of iron, manganese and ammonium nitrogen from groundwater.

  8. A high recovery membrane process for purification of low-level radioactive liquid waste

    International Nuclear Information System (INIS)

    Al-Samadi, R.; Davloor, R.; Harper, B.

    2013-01-01

    An advanced Active Liquid Waste Treatment System (ALWTS) was designed placed in-service at the Bruce Nuclear Generating Station 'A' in 1999. As part of this unique system an innovative high recovery reverse osmosis system (ROS) was installed to concentrate the contaminants into a small retentate stream that can be processed on-site or sent off-site for disposal. The permeate is discharged to the lake. The overall permeate recovery of the system is greater than 98%. This patented system which saw its first commercial application at the station has now operated continuously for over thirteen years. It has enabled the ALWTS to consistently produce high quality effluent that exceeds environmental discharge limits. This paper discusses the high recovery membrane process its unique design features aimed at minimizing the volume of rejects its separation performance operating history. (author)

  9. Evaluation of Effectiveness Technological Process of Water Purification Exemplified on Modernized Water Treatment Plant at Otoczna

    Science.gov (United States)

    Jordanowska, Joanna; Jakubus, Monika

    2014-12-01

    The article presents the work of the Water Treatment Plant in the town of Otoczna, located in the Wielkopolska province, before and after the modernization of the technological line. It includes the quality characteristics of the raw water and treated water with particular emphasis on changes in the quality indicators in the period 2002 -2012 in relation to the physicochemical parameters: the content of total iron and total manganese, the ammonium ion as well as organoleptic parameters(colour and turbidity). The efficiency of technological processes was analysed, including the processes of bed start up with chalcedonic sand to remove total iron and manganese and ammonium ion. Based on the survey, it was found that the applied modernization helped solve the problem of water quality, especially the removal of excessive concentrations of iron, manganese and ammonium nitrogen from groundwater. It has been shown that one year after modernization of the technological line there was a high reduction degree of most parameters, respectively for the general iron content -99%, general manganese - 93% ammonia - 93%, turbidity - 94%. It has been proved, that chalcedonic turned out to be better filter material than quartz sand previously used till 2008. The studies have confirmed that the stage of modernization was soon followed by bed start-up for removing general iron from the groundwater. The stage of manganese removal required more time, about eight months for bed start-up. Furthermore, the technological modernization contributed to the improvement of the efficiency of the nitrification process.

  10. Chemical hot gas purification for biomass gasification processes; Chemische Heissgasreinigung bei Biomassevergasungsprozessen

    Energy Technology Data Exchange (ETDEWEB)

    Stemmler, Michael

    2010-07-01

    The German government decided to increase the percentage of renewable energy up to 20 % of all energy consumed in 2020. The development of biomass gasification technology is advanced compared to most of the other technologies for producing renewable energy. So the overall efficiency of biomass gasification processes (IGCC) already increased to values above 50 %. Therefore, the production of renewable energy attaches great importance to the thermochemical biomass conversion. The feedstock for biomass gasification covers biomasses such as wood, straw and further energy plants. The detrimental trace elements released during gasification of these biomasses, e.g. KCl, H{sub 2}S and HCl, cause corrosion and harm downstream devices. Therefore, gas cleaning poses an especial challenge. In order to improve the overall efficiency this thesis aims at the development of gas cleaning concepts for the allothermic, water blown gasification at 800 C and 1 bar (Guessing-Process) as well as for the autothermic, water and oxygen blown gasification at 950 C and 18 bar (Vaernamo-Process). Although several mechanisms for KCl- and H{sub 2}S-sorption are already well known, the achievable reduction of the contamination concentration is still unknown. Therefore, calculations on the produced syngas and the chemical hot gas cleaning were done with a thermodynamic process model using SimuSage. The syngas production was included in the calculations because the knowledge of the biomass syngas composition is very limited. The results of these calculations prove the dependence of syngas composition on H{sub 2}/C-ratio and ROC (Relative Oxygen Content). Following the achievable sorption limits were detected via experiments. The KCl containing syngases were analysed by molecular beam mass spectrometry (MBMS). Furthermore, an optimised H{sub 2}S-sorbent was developed because the examined sorbents exceeded the sorption limit of 1 ppmv. The calculated sorption limits were compared to the limits

  11. Dendrimers as Carriers for siRNA Delivery and Gene Silencing: A Review

    Directory of Open Access Journals (Sweden)

    Jiangyu Wu

    2013-01-01

    Full Text Available RNA interference (RNAi was first literaturally reported in 1998 and has become rapidly a promising tool for therapeutic applications in gene therapy. In a typical RNAi process, small interfering RNAs (siRNA are used to specifically downregulate the expression of the targeted gene, known as the term “gene silencing.” One key point for successful gene silencing is to employ a safe and efficient siRNA delivery system. In this context, dendrimers are emerging as potential nonviral vectors to deliver siRNA for RNAi purpose. Dendrimers have attracted intense interest since their emanating research in the 1980s and are extensively studied as efficient DNA delivery vectors in gene transfer applications, due to their unique features based on the well-defined and multivalent structures. Knowing that DNA and RNA possess a similar structure in terms of nucleic acid framework and the electronegative nature, one can also use the excellent DNA delivery properties of dendrimers to develop effective siRNA delivery systems. In this review, the development of dendrimer-based siRNA delivery vectors is summarized, focusing on the vector features (siRNA delivery efficiency, cytotoxicity, etc. of different types of dendrimers and the related investigations on structure-activity relationship to promote safe and efficient siRNA delivery system.

  12. Dendrimers as Carriers for siRNA Delivery and Gene Silencing: A Review

    Science.gov (United States)

    Huang, Weizhe; He, Ziying

    2013-01-01

    RNA interference (RNAi) was first literaturally reported in 1998 and has become rapidly a promising tool for therapeutic applications in gene therapy. In a typical RNAi process, small interfering RNAs (siRNA) are used to specifically downregulate the expression of the targeted gene, known as the term “gene silencing.” One key point for successful gene silencing is to employ a safe and efficient siRNA delivery system. In this context, dendrimers are emerging as potential nonviral vectors to deliver siRNA for RNAi purpose. Dendrimers have attracted intense interest since their emanating research in the 1980s and are extensively studied as efficient DNA delivery vectors in gene transfer applications, due to their unique features based on the well-defined and multivalent structures. Knowing that DNA and RNA possess a similar structure in terms of nucleic acid framework and the electronegative nature, one can also use the excellent DNA delivery properties of dendrimers to develop effective siRNA delivery systems. In this review, the development of dendrimer-based siRNA delivery vectors is summarized, focusing on the vector features (siRNA delivery efficiency, cytotoxicity, etc.) of different types of dendrimers and the related investigations on structure-activity relationship to promote safe and efficient siRNA delivery system. PMID:24288498

  13. Separation and Purification of Mineral Salts from Spacecraft Wastewater Processing via Electrostatic Beneficiation

    Science.gov (United States)

    Miles, John D., II; Lunn, Griffin

    2013-01-01

    Electrostatic separation is a class of material processing technologies commonly used for the sorting of coarse mixtures by means of electrical forces acting on charged or polarized particles. Most if not all of the existing tribo-electrostatic separators had been initially developed for mineral ores beneficiation. It is a well-known process that has been successfully used to separate coal from minerals. Potash (potassium) enrichment where underground salt mines containing large amounts of sodium is another use of this techno logy. Through modification this technology can be used for spacecraft wastewater brine beneficiation. This will add in closing the gap beeen traveling around Earth's Gravity well and long-term space explorations. Food has been brought on all man missions, which is why plant growth for food crops continues to be of interest to NASA. For long-term mission considerations food productions is one of the top priorities. Nutrient recovery is essential for surviving in or past low earth orbit. In our advance bio-regenerative process instead of nitrogen gas produced; soluble nitrate salts that can be recovered for plant fertilizer would be produced instead. The only part missing is the beneficiation of brine to separate the potassium from the sodium. The use of electrostatic beneficiation in this experiment utilizes the electrical charge differences between aluminum and dried brine by surface contact. The helixes within the aluminum tribocharger allows for more surface contact when being agitated. When two materials are in contact, the material with the highest affinity for electrons becomes negatively charged, while the other becomes positively charged. This contact exchange of charge may cause the particles to agglomerate depending on their residence time within the tribocharger, compromising the efficiency of separation. The aim of this experiment is to further the development in electrostatic beneficiation by optimizing the separation of ersatz and

  14. Separation and purification of uranium product from thorium in thorex process by precipitation technique

    International Nuclear Information System (INIS)

    Ramanujam, A.; Dhami, P.S.; Gopalakrishnan, V.; Mukherjee, A.; Dhumwad, R.K.

    1989-01-01

    A sequential precipitation technique is reported for the separation of uranium and thorium present in the uranium product stream of a single cycle 5 per cent TBP Thorex Process. It involves the precipitation of thorium as oxalate in 1M HNO 3 medium at 60-70degC and after filtration, precipitation of uranium as ammonium diuranate at 80-90degC from the oxalate supernatant. This technique has several advantages over the ion-exchange process normally used for treating these products. In order to meet the varying feed conditions, this method has been tested for feeds containing 10 g/1 uranium and 1-50 g/1 thorium in 1-6M HNO 3 . Various parameters like feed acidities, uranium and thorium concentrations, excess oxalic acid concentrations in the oxalate supernatant, precipitation temperatures, precipitate wash volumes etc. have been optimised to obtain more than 99 per cent recovery of thorium and uranium as their oxides with less than 50 ppm uranium losses to ammonium diuranate filtrate. The distribution patterns of different fission products and stainless steel corrosion products during various steps of this procedure have also been studied. For simulating the actual Thorex plant scale operation, experiments have been conducted with 25g and 100g lots of uranium per batch. (author). 6 tabs., 8 figs., 22 refs

  15. Separation and purification of hemicellulose-derived saccharides from wood hydrolysate by combined process.

    Science.gov (United States)

    Wang, Xiaojun; Zhuang, Jingshun; Jiang, Jungang; Fu, Yingjuan; Qin, Menghua; Wang, Zhaojiang

    2015-11-01

    Prehydrolysis of wood biomass prior to kraft cooking provides a stream containing hemicellulose-derived saccharides (HDSs) but also undesired non-saccharide compounds (NSCs) that were resulted from lignin depolymerization and carbohydrate degradation. In this study, a combined process consisting of lime treatment, resin adsorption, and gel filtration was developed to separate HDSs from NSCs. The macro-lignin impurities that accounted for 32.2% of NSCs were removed by lime treatment at 1.2% dosage with negligible HDSs loss. The majority of NSCs, lignin-derived phenolics, were eliminated by mixed bed ion exchange resin, elevating NSCs removal to 94.0%. The remaining NSCs, furfural and hydroxymethylfurfural, were excluded from HDSs by gel filtration. Chemical composition analysis showed that xylooligosaccharides (XOS) with the degree of depolymerization from 2 to 6 accounted for 28% of the total purified HDSs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Ionic behavior of treated water at a water purification plant

    OpenAIRE

    Yanagida, Kazumi; Kawahigashi, Tatsuo

    2012-01-01

    [Abstract] Water at each processing stage in a water purification plant was extracted and analyzed to investigate changes of water quality. Investigations of water at each processing stage at the water purification plant are discussed herein.

  17. Microfluidic Synthesis of Highly Potent Limit-size Lipid Nanoparticles for In Vivo Delivery of siRNA

    Directory of Open Access Journals (Sweden)

    Nathan M Belliveau

    2012-01-01

    Full Text Available Lipid nanoparticles (LNP are the leading systems for in vivo delivery of small interfering RNA (siRNA for therapeutic applications. Formulation of LNP siRNA systems requires rapid mixing of solutions containing cationic lipid with solutions containing siRNA. Current formulation procedures employ macroscopic mixing processes to produce systems 70-nm diameter or larger that have variable siRNA encapsulation efficiency, homogeneity, and reproducibility. Here, we show that microfluidic mixing techniques, which permit millisecond mixing at the nanoliter scale, can reproducibly generate limit size LNP siRNA systems 20 nm and larger with essentially complete encapsulation of siRNA over a wide range of conditions with polydispersity indexes as low as 0.02. Optimized LNP siRNA systems produced by microfluidic mixing achieved 50% target gene silencing in hepatocytes at a dose level of 10 µg/kg siRNA in mice. We anticipate that microfluidic mixing, a precisely controlled and readily scalable technique, will become the preferred method for formulation of LNP siRNA delivery systems.

  18. Optimization of electrocoagulation (EC) process for the purification of a real industrial wastewater from toxic metals.

    Science.gov (United States)

    Gatsios, Evangelos; Hahladakis, John N; Gidarakos, Evangelos

    2015-05-01

    In the present work, the efficiency evaluation of electrocoagulation (EC) in removing toxic metals from a real industrial wastewater, collected from Aspropyrgos, Athens, Greece was investigated. Manganese (Mn), copper (Cu) and zinc (Zn) at respective concentrations of 5 mg/L, 5 mg/L and 10 mg/L were present in the wastewater (pH=6), originated from the wastes produced by EBO-PYRKAL munitions industry and Hellenic Petroleum Elefsis Refineries. The effect of operational parameters such as electrode combination and distance, applied current, initial pH and initial metal concentration, was studied. The results indicated that Cu and Zn were totally removed in all experiments, while Mn exhibited equally high removal percentages (approximately 90%). Decreasing the initial pH and increasing the distance between electrodes, resulted in a negative effect on the efficiency and energy consumption of the process. On the other hand, increasing the applied current, favored metal removal but resulted in a power consumption increase. Different initial concentrations did not affect metal removal efficiency. The optimal results, regarding both cost and EC efficiency, were obtained with a combination of iron electrodes, at 2 cm distance, at initial current of 0.1 A and pH=6. After 90 min of treatment, maximum removal percentages obtained were 89% for Mn, 100% for Cu and 100% for Zn, at an energy consumption of 2.55 kWh/m(3). Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Continuous processing of recombinant proteins: integration of refolding and purification using simulated moving bed size-exclusion chromatography with buffer recycling.

    Science.gov (United States)

    Wellhoefer, Martin; Sprinzl, Wolfgang; Hahn, Rainer; Jungbauer, Alois

    2014-04-11

    Continuous processing of recombinant proteins was accomplished by combining continuous matrix-assisted refolding and purification by tandem simulated moving bed (SMB) size-exclusion chromatography (SEC). Recombinant proteins, N(pro) fusion proteins from inclusion bodies were dissolved with NaOH and refolded in the SMB system with a closed-loop set-up with refolding buffer as the desorbent buffer and buffer recycling of the refolding buffer of the raffinate by tangential flow filtration. For further purification of the refolded proteins, a second SMB operation also based on SEC was added. The whole system could be operated isocratically with refolding buffer as the desorbent buffer, and buffer recycling could also be applied in the purification step. Thus, a significant reduction in buffer consumption was achieved. The system was evaluated with two proteins, the N(pro) fusion pep6His and N(pro) fusion MCP-1. Refolding solution, which contained residual N(pro) fusion peptide, the cleaved autoprotease N(pro), and the cleaved target peptide was used as feed solution. Full separation of the cleaved target peptide from residual proteins was achieved at a purity and recovery in the raffinate and extract, respectively, of approximately 100%. In addition, more than 99% of the refolding buffer of the raffinate was recycled. A comparison of throughput, productivity, and buffer consumption of the integrated continuous process with two batch processes demonstrated that up to 60-fold higher throughput, up to 180-fold higher productivity, and at least 28-fold lower buffer consumption can be obtained by the integrated continuous process, which compensates for the higher complexity. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. The bubble method of water purification

    Science.gov (United States)

    Smirnov, B. M.; Babaeva, N. Yu.; Naidis, G. V.; Panov, V. A.; Saveliev, A. S.; Son, E. E.; Tereshonok, D. V.

    2018-02-01

    The processes of water purification from admixture molecules are analyzed. The purification rate is limited due to a low diffusion coefficient of the admixture molecules in water. At non-small concentrations of the admixture molecules, the water purication can proceed through association of molecules in condensed nanoparticles which fall on the bottom of the water volume. The rate of association may be increased in an external electric field, but in reality this cannot change significantly the rate of the purification process. The bubble method of water purification is considered, where air bubbles formed at the bottom of the water volume, transfer admixture molecules to the interface. This method allows one to clean small water volumes fast. This mechanism of water purification is realized experimentally and exhibits the promises of the bubble purification method.

  1. Extraction and purification of high added value compounds from by-products of the winemaking chain using alternative/nonconventional processes/technologies.

    Science.gov (United States)

    Yammine, Sami; Brianceau, Sylène; Manteau, Sébastien; Turk, Mohammad; Ghidossi, Rémy; Vorobiev, Eugène; Mietton-Peuchot, Martine

    2018-05-24

    Grape byproducts are today considered as a cheap source of valuable compounds since existent technologies allow the recovery of target compounds and their recycling. The goal of the current article is to explore the different recovery stages used by both conventional and alternative techniques and processes. Alternative pre-treatments techniques reviewed are: ultrasounds, pulsed electric fields and high voltage discharges. In addition, nonconventional solvent extraction under high pressure, specifically, supercritical fluid extraction and subcritical water extraction are discussed. Finally alternative purification technologies, for example membrane processing were also examined. The intent is to describe the mechanisms involved by these alternative technologies and to summarize the work done on the improvement of the extraction process of phenolic compounds from winery by-products. With a focus on the developmental stage of each technology, highlighting the research need and challenges to be overcome for an industrial implementation of these unitary operations in the overall extraction process. A critical comparison of conventional and alternative techniques will be reviewed for ethe pre-treatment of raw material, the diffusion of polyphenols and the purification of these high added value compounds. This review intends to give the reader some key answers (costs, advantages, drawbacks) to help in the choice of alternative technologies for extraction purposes.

  2. siRNA for Influenza Therapy

    Directory of Open Access Journals (Sweden)

    Sailen Barik

    2010-07-01

    Full Text Available Influenza virus is one of the most prevalent and ancient infections in humans. About a fifth of world's population is infected by influenza virus annually, leading to high morbidity and mortality, particularly in infants, the elderly and the immunocompromised. In the US alone, influenza outbreaks lead to roughly 30,000 deaths each year. Current vaccines and anti-influenza drugs are of limited use due to high mutation rate of the virus and side effects. In recent years, RNA interference, triggered by synthetic short interfering RNA (siRNA, has rapidly evolved as a potent antiviral regimen. Properly designed siRNAs have been shown to function as potent inhibitors of influenza virus replication. The siRNAs outperform traditional small molecule antivirals in a number of areas, such as ease of design, modest cost, and fast turnaround. Although specificity and tissue delivery remain major bottlenecks in the clinical applications of RNAi in general, intranasal application of siRNA against respiratory viruses including, but not limited to influenza virus, has experienced significant success and optimism, which is reviewed here.

  3. siRNA for Influenza Therapy.

    Science.gov (United States)

    Barik, Sailen

    2010-07-01

    Influenza virus is one of the most prevalent and ancient infections in humans. About a fifth of world's population is infected by influenza virus annually, leading to high morbidity and mortality, particularly in infants, the elderly and the immunocompromised. In the US alone, influenza outbreaks lead to roughly 30,000 deaths each year. Current vaccines and anti-influenza drugs are of limited use due to high mutation rate of the virus and side effects. In recent years, RNA interference, triggered by synthetic short interfering RNA (siRNA), has rapidly evolved as a potent antiviral regimen. Properly designed siRNAs have been shown to function as potent inhibitors of influenza virus replication. The siRNAs outperform traditional small molecule antivirals in a number of areas, such as ease of design, modest cost, and fast turnaround. Although specificity and tissue delivery remain major bottlenecks in the clinical applications of RNAi in general, intranasal application of siRNA against respiratory viruses including, but not limited to influenza virus, has experienced significant success and optimism, which is reviewed here.

  4. Uranium hexafluoride purification

    International Nuclear Information System (INIS)

    Araujo, Eneas F. de

    1986-01-01

    Uranium hexafluoride might contain a large amount of impurities after manufacturing or handling. Three usual methods of purification of uranium hexafluoride were presented: selective sorption, sublimation, and distillation. Since uranium hexafluoride usually is contaminated with hydrogen fluoride, a theoretical study of the phase equilibrium properties was performed for the binary system UF 6 -HF. A large deviation from the ideal solution behaviour was observed. A purification unity based on a constant reflux batch distillation process was developed. A procedure was established in order to design the re boiler, condenser and packed columns for the UF 6 -HF mixture separation. A bench scale facility for fractional distillation of uranium hexafluoride was described. Basic operations for that facility and results extracted from several batches were discussed. (author)

  5. Abundance and diversity of ammonia-oxidizing archaea and bacteria on granular activated carbon and their fates during drinking water purification process.

    Science.gov (United States)

    Niu, Jia; Kasuga, Ikuro; Kurisu, Futoshi; Furumai, Hiroaki; Shigeeda, Takaaki; Takahashi, Kazuhiko

    2016-01-01

    Ammonia is a precursor to trichloramine, which causes an undesirable chlorinous odor. Granular activated carbon (GAC) filtration is used to biologically oxidize ammonia during drinking water purification; however, little information is available regarding the abundance and diversity of ammonia-oxidizing archaea (AOA) and bacteria (AOB) associated with GAC. In addition, their sources and fates in water purification process remain unknown. In this study, six GAC samples were collected from five full-scale drinking water purification plants in Tokyo during summer and winter, and the abundance and community structure of AOA and AOB associated with GAC were studied in these two seasons. In summer, archaeal and bacterial amoA genes on GACs were present at 3.7 × 10(5)-3.9 × 10(8) gene copies/g-dry and 4.5 × 10(6)-4.2 × 10(8) gene copies/g-dry, respectively. In winter, archaeal amoA genes remained at the same level, while bacterial amoA genes decreased significantly for all GACs. No differences were observed in the community diversity of AOA and AOB from summer to winter. Phylogenetic analysis revealed high AOA diversity in group I.1a and group I.1b in raw water. Terminal-restriction fragment length polymorphism analysis of processed water samples revealed that AOA diversity decreased dramatically to only two OTUs in group I.1a after ozonation, which were identical to those detected on GAC. It suggests that ozonation plays an important role in determining AOA diversity on GAC. Further study on the cell-specific activity of AOA and AOB is necessary to understand their contributions to in situ nitrification performance.

  6. Purification of crude biodiesel using dry washing and membrane technologies

    OpenAIRE

    Atadashi, I.M.

    2015-01-01

    Purification of crude biodiesel is mandatory for the fuel to meet the strict international standard specifications for biodiesel. Therefore, this paper carefully analyzed recently published literatures which deal with the purification of biodiesel. As such, dry washing technologies and the most recent membrane biodiesel purification process have been thoroughly examined. Although purification of biodiesel using dry washing process involving magnesol and ion exchange resins provides high-quali...

  7. siRNA as an alternative therapy against viral infections

    Directory of Open Access Journals (Sweden)

    Hana A. Pawestri

    2012-07-01

    Full Text Available siRNA (small interfering ribonucleic acid adalah sebuah metode yang dapat digunakan untuk mengatasi infeksi virus yang prinsip kerjanya berdasarkan metode komplementer dsRNA (double stranded RNA pada RNA virus sehingga menyebabkan kegagalan proses transkripsi (silencing.  Untuk lebih memahami bagaimana proses kerja dan ulasan penelitian siRNA yang terkini, di dalam tulisan ini ditinjau siRNA sebagai metoda yang dikembangkan untuk mengatasi infeksi dan meneliti efeknya pada replikasi beberapa virus seperti Hepatitis C, Influenza, Polio, dan HIV. Kami menemukan bahwa urutan basa nukleotida dari target siRNA sangat penting. Hal tersebut harus homolog dengan target RNA virus dan tidak menganggu RNA sel inang. Untuk mengurangi kegagalan terapi siRNA oleh adanya mutasi, digunakan beberapa siRNA yang sekaligus menjadi target RNA virus yang berbeda. Namun demikian, terapi siRNA masih menghadapi beberapa kesulitan seperti pengiriman (transfer khusus ke jaringan yang terinfeksi dan perlindungan siRNA dari perusakan oleh nuklease. Berdasarkan beberapa penelitian yang telah dilakukan, siRNA dapat digunakan sebagai alternatif untuk mengobati infeksi yang disebabkan oleh virus. Terapi tersebut direkomendasikan untuk dilakukan uji klinis dengan memperhatikan beberapa aspek seperti desain siRNA dan mekanisme transfer. (Health Science Indones 2010; 1: 58 - 65 Kata kunci: siRNA, infeksi virus, target virus, alternatif terapi Abstract SiRNA is a promising method to deal with viral infections. The principle of siRNA is based on the complementarily of (synthetic dsRNA to an RNA virus which, in consequence, will be silenced. Many studies are currently examining the effects of siRNA on replication of diverse virus types like Hepatitis C, polio and HIV. The choice of the siRNA target sequence is crucial. It has to be very homologous to the target RNA, but it cannot target RNA of the host cell. To reduce the possibility for the virus to escape from the siRNA therapy by

  8. Hydrogen purification by periodic adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Barg, Christian; Secchi, Argimiro R.; Trierweiler, Jorge O. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Dept. de Engenharia Quimica]. E-mail: cbarg@enq.ufrgs.br; arge@enq.ufrgs.br; jorge@enq.ufrgs.br

    2000-07-01

    The periodic adsorption processes have been widely used for industrial applications, mainly because it spends less energy than the usual gas separation processes, like the cryogenic distillation. The largest commercial application of periodic adsorption processes is the pressure swing adsorption (PSA) applied to hydrogen purification. Although its wide use in the chemical and petrochemical industry, there are no reports in the open literature about complete modeling studies of a complex commercial unit, with multiple adsorbents and multiple beds and several feed components. This study has as objective the modeling, optimization and dynamical analysis of an industrial PSA unit for hydrogen purification. (author)

  9. SiRNAs in vivo imaging: methodology of fluorine-18 radiolabelling and application for the optimization of the siRNAs biodistribution and pharmaceutical properties

    International Nuclear Information System (INIS)

    Viel, Th.

    2008-01-01

    As RNA interference is a natural process which enables eukaryote cells to regulate the gene expressions, to control transposons, and to struggle against some viruses, two imagery techniques have been used in this research, i.e. optical imagery and Positron Emission Tomography (PET) imagery, to study the various modifications of the small interferential RNAs (siRNA). Different chemically modified siRNAs have been prepared and their in vitro activity, their in vivo metabolism (by HPLC analysis), their bio-distribution and their pharmacokinetic properties (by PET imagery) after marking them with fluorine-18. Their in vivo activity has been assessed by optical imagery

  10. Dendrimers for siRNA Delivery

    Directory of Open Access Journals (Sweden)

    Swati Biswas

    2013-02-01

    Full Text Available Since the discovery of the “starburst polymer”, later renamed as dendrimer, this class of polymers has gained considerable attention for numerous biomedical applications, due mainly to the unique characteristics of this macromolecule, including its monodispersity, uniformity, and the presence of numerous functionalizable terminal groups. In recent years, dendrimers have been studied extensively for their potential application as carriers for nucleic acid therapeutics, which utilize the cationic charge of the dendrimers for effective dendrimer-nucleic acid condensation. siRNA is considered a promising, versatile tool among various RNAi-based therapeutics, which can effectively regulate gene expression if delivered successfully inside the cells. This review reports on the advancements in the development of dendrimers as siRNA carriers.

  11. Detection of small interfering RNA (siRNA) by mass spectrometry procedures in doping controls.

    Science.gov (United States)

    Thomas, Andreas; Walpurgis, Katja; Delahaut, Philippe; Kohler, Maxie; Schänzer, Wilhelm; Thevis, Mario

    2013-01-01

    Uncovering manipulation of athletic performance via small interfering (si)RNA is an emerging field in sports drug testing. Due to the potential to principally knock down every target gene in the organism by means of the RNA interference pathway, this facet of gene doping has become a realistic scenario. In the present study, two distinct model siRNAs comprising 21 nucleotides were designed as double strands which were perfect counterparts to a sequence of the respective messenger RNA coding the muscle regulator myostatin of Rattus norvegicus. Several modified nucleotides were introduced in both the sense and the antisense strand comprising phosphothioates, 2'-O-methylation, 2'-fluoro-nucleotides, locked nucleic acids and a cholesterol tag at the 3'-end. The model siRNAs were applied to rats at 1 mg/kg (i.v.) and blood as well as urine samples were collected. After isolation of the RNA by means of a RNA purification kit, the target analytes were detected by liquid chromatography - high resolution/high accuracy mass spectrometry (LC-HRMS). Analytes were detected as modified nucleotides after alkaline hydrolysis, as intact oligonucleotide strands (top-down) and by means of denaturing SDS-PAGE analysis. The gel-separated siRNA was further subjected to in-gel hydrolysis with different RNases and subsequent identification of the fragments by untargeted LC-HRMS analysis (bottom-up, 'experimental RNomics'). Combining the results of all approaches, the identification of several 3'-truncated urinary metabolites was accomplished and target analytes were detected up to 24 h after a single administration. Simultaneously collected blood samples yielded no promising results. The methods were validated and found fit-for-purpose for doping controls. Copyright © 2013 John Wiley & Sons, Ltd.

  12. The various sodium purification techniques

    International Nuclear Information System (INIS)

    Courouau, J.L.; Masse, F.; Rodriguez, G.; Latge, C.; Redon, B.

    1997-01-01

    In the framework of sodium waste treatment, the sodium purification phase plays an essential role in the chain of operations leading to the transformation of the active sodium, considered as waste, into a stable sodium salt. The objectives of the purification operations are: To keep a low impurity level, particularly a low concentration in oxygen and hydrogen, in order to allow its transfer to a processing plant, and in order to avoid risks of plugging and/or corrosion in sodium facilities; To reduce the sodium activity in order to limit the dose rate close to the facilities, and in order to reduce the activity of the liquid and gaseous effluents. After a recall of the different kind of impurities that can be present in sodium, and of the different purification methods that could be associated with, the following points are highlighted: (i) Oxygen and hydrogen purification needs, and presentation of some selection criteria for a purification unit adapted to a sodium processing plant, as well as 2 cold trap concepts that are in accordance with these criteria: PSICHOS and PIRAMIDE. (ii) Tritium reduction in a bulk of liquid sodium by swamping, isotopic exchange, or permeation throughout a membrane. (iii) Caesium trapping on carbonaceous matrix. The main matrices used at present are R.V.C. (Reticulated Vitreous Carbon) and Actitex/Pica products. Tests in the laboratory and on an experimental device have demonstrated the performances of these materials, which are able to reduce sodium activity in Cs 134 and Cs 137 to very low values. The sodium purification processes as regards to the hydrogen, oxygen and caesium, that are aimed at facilitating the subsequent treatment of sodium, are therefore mastered operations. Regarding the operations associated with the reduction of the tritium activity, the methods are in the process of being qualified, or to be qualified. (author)

  13. Sulfur hexafluoride purification from mixtures with air: a process feasibility study for the Holifield Heavy Ion Research Facility

    International Nuclear Information System (INIS)

    Perona, J.J.

    1979-01-01

    A preliminary feasibility study was made for the purification of SF 6 vapor contaminated with air for application at the Holifield Heavy Ion Research Facility. Liquefaction appears to be a good way to recover about 90% of the SF 6 if it is badly contaminated (15% air), and even greater recovery will be possible for mixtures containing less air. Where liquefaction is insufficient alone, adsorption of SF 6 on activated carbon at -50 0 F looks promising. Two carbon beds each containing about 500 lb of carbon should be sufficient. The refrigeration system for liquefaction and adsorption would have a capacity of about 2 tons. As alternatives, the use of molecular sieves to trap out the air was investigated, but such a bed would require at least 15,000 lb of molecular sieves and very long cycle times. A large-scale desublimer was investigated and appears workable but would require some development work to permit design work to proceed with confidence

  14. Strong ion exchange in centrifugal partition extraction (SIX-CPE): effect of partition cell design and dimensions on purification process efficiency.

    Science.gov (United States)

    Hamzaoui, Mahmoud; Hubert, Jane; Reynaud, Romain; Marchal, Luc; Foucault, Alain; Renault, Jean-Hugues

    2012-07-20

    The aim of this article was to evaluate the influence of the column design of a hydrostatic support-free liquid-liquid chromatography device on the process efficiency when the strong ion-exchange (SIX) development mode is used. The purification of p-hydroxybenzylglucosinolate (sinalbin) from a crude aqueous extract of white mustard seeds (Sinapis alba L.) was achieved on two types of devices: a centrifugal partition chromatograph (CPC) and a centrifugal partition extractor (CPE). They differ in the number, volume and geometry of their partition cells. The SIX-CPE process was evaluated in terms of productivity and sinalbin purification capability as compared to previously optimized SIX-CPC protocols that were carried out on columns of 200 mL and 5700 mL inner volume, respectively. The objective was to determine whether the decrease in partition cell number, the increase in their volume and the use of a "twin cell" design would induce a significant increase in productivity by applying higher mobile phase flow rate while maintaining a constant separation quality. 4.6g of sinalbin (92% recovery) were isolated from 25 g of a crude white mustard seed extract, in only 32 min and with a purity of 94.7%, thus corresponding to a productivity of 28 g per hour and per liter of column volume (g/h/LV(c)). Therefore, the SIX-CPE process demonstrates promising industrial technology transfer perspectives for the large-scale isolation of ionized natural products. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Materials for Molybdenum 99 purification

    International Nuclear Information System (INIS)

    Wilkinson, M. Victoria; Mondino, Angel V.; Manzini, Alberto C.

    2003-01-01

    The National Atomic Energy Commission (CNEA) produces fission Mo 99, an isotope of wide use in nuclear medicine. In order to simplify the current Mo 99 production process, to shorten its duration and reduce impurities in the final product, alternative methods for purification steps were looked for. In this work a variety of new materials for the purification columns were designed, all of them with carbon. These materials were studied and a material which contribute with the best results for molybdenum retention, was selected. The preparation procedure and the working conditions were determined. (author)

  16. Efficient inhibition of fibroblast proliferation and collagen expression by ERK2 siRNAs

    International Nuclear Information System (INIS)

    Li, Fengfeng; Fan, Cunyi; Cheng, Tao; Jiang, Chaoyin; Zeng, Bingfang

    2009-01-01

    Transforming growth factor-β1 and fibroblast growth factor-2 play very important roles in fibroblast proliferation and collagen expression. These processes lead to the formation of joint adhesions through the SMAD and MAPK pathways, in which ERK2 is supposed to be crucial. Based on these assumptions, lentivirus (LV)-mediated small interfering RNAs (siRNAs) targeting ERK2 were used to suppress the proliferation and collagen expression of rat joint adhesion tissue fibroblasts (RJATFs). Among four siRNAs examined, siRNA1 caused an 84% reduction in ERK2 expression (p < 0.01) and was selected as the most efficient siRNA for use in this study. In subsequent experiments, significant downregulation of types I and III collagen were observed by quantitative RT-PCR and Western blot analyses. MTT assays and flow cytometry revealed marked inhibition of RJATF proliferation, but no apoptosis. In conclusion, LV-mediated ERK2 siRNAs may represent novel therapies or drug targets for preventing joint adhesion formation.

  17. Kinetic analysis of the effects of target structure on siRNA efficiency

    Science.gov (United States)

    Chen, Jiawen; Zhang, Wenbing

    2012-12-01

    RNAi efficiency for target cleavage and protein expression is related to the target structure. Considering the RNA-induced silencing complex (RISC) as a multiple turnover enzyme, we investigated the effect of target mRNA structure on siRNA efficiency with kinetic analysis. The 4-step model was used to study the target cleavage kinetic process: hybridization nucleation at an accessible target site, RISC-mRNA hybrid elongation along with mRNA target structure melting, target cleavage, and enzyme reactivation. At this model, the terms accounting for the target accessibility, stability, and the seed and the nucleation site effects are all included. The results are in good agreement with that of experiments which show different arguments about the structure effects on siRNA efficiency. It shows that the siRNA efficiency is influenced by the integrated factors of target's accessibility, stability, and the seed effects. To study the off-target effects, a simple model of one siRNA binding to two mRNA targets was designed. By using this model, the possibility for diminishing the off-target effects by the concentration of siRNA was discussed.

  18. Future of antibody purification.

    Science.gov (United States)

    Low, Duncan; O'Leary, Rhona; Pujar, Narahari S

    2007-03-15

    Antibody purification seems to be safely ensconced in a platform, now well-established by way of multiple commercialized antibody processes. However, natural evolution compels us to peer into the future. This is driven not only by a large, projected increase in the number of antibody therapies, but also by dramatic improvements in upstream productivity, and process economics. Although disruptive technologies have yet escaped downstream processes, evolution of the so-called platform is already evident in antibody processes in late-stage development. Here we perform a wide survey of technologies that are competing to be part of that platform, and provide our [inherently dangerous] assessment of those that have the most promise.

  19. Lysine purification with cation exchange resin

    International Nuclear Information System (INIS)

    Khayati, GH.; Mottaghi Talab, M.; Hamooni Hagheeghat, M.; Fatemi, M.

    2003-01-01

    L-lysine is an essential amino acid for the growth most of animal species and the number one limiting amino acid for poultry. After production and biomass removal by filtration and centrifugation, the essential next step is the lysine purification and recovery. There are different methods for lysine purification. The ion exchange process is one of the most commonly used purification methods. Lysine recovery was done from broth by ion exchange resin in three different ways: repeated passing, resin soaking and the usual method. Impurities were isolated from the column by repeated wash with distilled water. Recovery and purification was done with NH 4 OH and different alcohol volumes respectively. The results showed that repeated passing is the best method for lysine absorption (maximum range 86.21 %). Washing with alkali solution revealed that most of lysine is obtained in the first step of washing. The highest degree of lysine purification was achieved with the use of 4 volumes of alcohol

  20. siRNAs targeted to certain polyadenylation sites promote specific, RISC-independent degradation of messenger RNAs.

    Science.gov (United States)

    Vickers, Timothy A; Crooke, Stanley T

    2012-07-01

    While most siRNAs induce sequence-specific target mRNA cleavage and degradation in a process mediated by Ago2/RNA-induced silencing complex (RISC), certain siRNAs have also been demonstrated to direct target RNA reduction through deadenylation and subsequent degradation of target transcripts in a process which involves Ago1/RISC and P-bodies. In the current study, we present data suggesting that a third class of siRNA exist, which are capable of promoting target RNA reduction that is independent of both Ago and RISC. These siRNAs bind the target messenger RNA at the polyA signal and are capable of redirecting a small amount of polyadenylation to downstream polyA sites when present, however, the majority of the activity appears to be due to inhibition of polyadenylation or deadenylation of the transcript, followed by exosomal degradation of the immature mRNA.

  1. Platinum Interference with siRNA Non-seed Regions Fine-Tunes Silencing Capacity

    DEFF Research Database (Denmark)

    Hedman, Hanna K; Kirpekar, Finn; Elmroth, Sofi K C

    2011-01-01

    expression, and the other one focused on the function of endogenous miRNAs. In both cases, the active molecule consists of a ∼20-nucleotide-long RNA duplex. In the siRNA case, improved systemic stability is of central interest for its further development toward clinical applications. With respect to mi......RNA processing and function, understanding its influence on mRNA targeting and the silencing ability of individual miRNAs, e.g., under pathological conditions, remains a scientific challenge. In the present study, a model system is presented where the influence of the two clinically used anticancer drugs......, cisplatin and oxaliplatin, on siRNA's silencing capacity has been evaluated. More specifically, siRNAs targeting the 3' UTR region of Wnt-5a mRNA (NM_003352) were constructed, and the biologically active antisense RNA strand was pre-platinated. Platinum adducts were detected and characterized...

  2. Development, upscaling and validation of the purification process for human-cl rhFVIII (Nuwiq®), a new generation recombinant factor VIII produced in a human cell-line.

    Science.gov (United States)

    Winge, Stefan; Yderland, Louise; Kannicht, Christoph; Hermans, Pim; Adema, Simon; Schmidt, Torben; Gilljam, Gustav; Linhult, Martin; Tiemeyer, Maya; Belyanskaya, Larisa; Walter, Olaf

    2015-11-01

    Human-cl rhFVIII (Nuwiq®), a new generation recombinant factor VIII (rFVIII), is the first rFVIII produced in a human cell-line approved by the European Medicines Agency. To describe the development, upscaling and process validation for industrial-scale human-cl rhFVIII purification. The purification process involves one centrifugation, two filtration, five chromatography columns and two dedicated pathogen clearance steps (solvent/detergent treatment and 20 nm nanofiltration). The key purification step uses an affinity resin (VIIISelect) with high specificity for FVIII, removing essentially all host-cell proteins with >80% product recovery. The production-scale multi-step purification process efficiently removes process- and product-related impurities and results in a high-purity rhFVIII product, with an overall yield of ∼50%. Specific activity of the final product was >9000 IU/mg, and the ratio between active FVIII and total FVIII protein present was >0.9. The entire production process is free of animal-derived products. Leaching of potential harmful compounds from chromatography resins and all pathogens tested were below the limit of quantification in the final product. Human-cl rhFVIII can be produced at 500 L bioreactor scale, maintaining high purity and recoveries. The innovative purification process ensures a high-purity and high-quality human-cl rhFVIII product with a high pathogen safety margin. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Surveillance of siRNA integrity by FRET imaging

    Science.gov (United States)

    Järve, Anne; Müller, Julius; Kim, Il-Han; Rohr, Karl; MacLean, Caroline; Fricker, Gert; Massing, Ulrich; Eberle, Florian; Dalpke, Alexander; Fischer, Roger; Trendelenburg, Michael F.; Helm, Mark

    2007-01-01

    Techniques for investigation of exogenous small interfering RNA (siRNA) after penetration of the cell are of substantial interest to the development of efficient transfection methods as well as to potential medical formulations of siRNA. A FRET-based visualization method including the commonplace dye labels fluorescein and tetramethylrhodamin (TMR) on opposing strands of siRNA was found compatible with RNA interference (RNAi). Investigation of spectral properties of three labelled siRNAs with differential FRET efficiencies in the cuvette, including pH dependence and FRET efficiency in lipophilic environments, identified the ratio of red and green fluorescence (R/G-ratio) as a sensitive parameter, which reliably identifies samples containing >90% un-degraded siRNA. Spectral imaging of siRNAs microinjected into cells showed emission spectra indistinguishable from those measured in the cuvette. These were used to establish a calibration curve for assessing the degradation state of siRNA in volume elements inside cells. An algorithm, applied to fluorescence images recorded in standard green and red fluorescence channels, produces R/G-ratio images of high spatial resolution, identifying volume elements in the cell with high populations of intact siRNA with high fidelity. To demonstrate the usefulness of this technique, the movement of intact siRNA molecules are observed after introduction into the cytosol by microinjection, standard transfection and lipofection with liposomes. PMID:17890733

  4. Bioinspired Materials for Water Purification

    Directory of Open Access Journals (Sweden)

    Alfredo Gonzalez-Perez

    2016-06-01

    Full Text Available Water scarcity issues associated with inadequate access to clean water and sanitation is a ubiquitous problem occurring globally. Addressing future challenges will require a combination of new technological development in water purification and environmental remediation technology with suitable conservation policies. In this scenario, new bioinspired materials will play a pivotal role in the development of more efficient and environmentally friendly solutions. The role of amphiphilic self-assembly on the fabrication of new biomimetic membranes for membrane separation like reverse osmosis is emphasized. Mesoporous support materials for semiconductor growth in the photocatalytic degradation of pollutants and new carriers for immobilization of bacteria in bioreactors are used in the removal and processing of different kind of water pollutants like heavy metals. Obstacles to improve and optimize the fabrication as well as a better understanding of their performance in small-scale and pilot purification systems need to be addressed. However, it is expected that these new biomimetic materials will find their way into the current water purification technologies to improve their purification/removal performance in a cost-effective and environmentally friendly way.

  5. Mass spectrometric detection of siRNA in plasma samples for doping control purposes.

    Science.gov (United States)

    Kohler, Maxie; Thomas, Andreas; Walpurgis, Katja; Schänzer, Wilhelm; Thevis, Mario

    2010-10-01

    Small interfering ribonucleic acid (siRNA) molecules can effect the expression of any gene by inducing the degradation of mRNA. Therefore, these molecules can be of interest for illicit performance enhancement in sports by affecting different metabolic pathways. An example of an efficient performance-enhancing gene knockdown is the myostatin gene that regulates muscle growth. This study was carried out to provide a tool for the mass spectrometric detection of modified and unmodified siRNA from plasma samples. The oligonucleotides are purified by centrifugal filtration and the use of an miRNA purification kit, followed by flow-injection analysis using an Exactive mass spectrometer to yield the accurate masses of the sense and antisense strands. Although chromatography and sensitive mass spectrometric analysis of oligonucleotides are still challenging, a method was developed and validated that has adequate sensitivity (limit of detection 0.25-1 nmol mL(-1)) and performance (precision 11-21%, recovery 23-67%) for typical antisense oligonucleotides currently used in clinical studies.

  6. Intranasal siRNA administration reveals IGF2 deficiency contributes to impaired cognition in Fragile X syndrome mice.

    Science.gov (United States)

    Pardo, Marta; Cheng, Yuyan; Velmeshev, Dmitry; Magistri, Marco; Eldar-Finkelman, Hagit; Martinez, Ana; Faghihi, Mohammad A; Jope, Richard S; Beurel, Eleonore

    2017-03-23

    Molecular mechanisms underlying learning and memory remain imprecisely understood, and restorative interventions are lacking. We report that intranasal administration of siRNAs can be used to identify targets important in cognitive processes and to improve genetically impaired learning and memory. In mice modeling the intellectual deficiency of Fragile X syndrome, intranasally administered siRNA targeting glycogen synthase kinase-3β (GSK3β), histone deacetylase-1 (HDAC1), HDAC2, or HDAC3 diminished cognitive impairments. In WT mice, intranasally administered brain-derived neurotrophic factor (BDNF) siRNA or HDAC4 siRNA impaired learning and memory, which was partially due to reduced insulin-like growth factor-2 (IGF2) levels because the BDNF siRNA- or HDAC4 siRNA-induced cognitive impairments were ameliorated by intranasal IGF2 administration. In Fmr1 -/- mice, hippocampal IGF2 was deficient, and learning and memory impairments were ameliorated by IGF2 intranasal administration. Therefore intranasal siRNA administration is an effective means to identify mechanisms regulating cognition and to modulate therapeutic targets.

  7. Reductively Responsive Hydrogel Nanoparticles with Uniform Size, Shape, and Tunable Composition for Systemic siRNA Delivery in Vivo.

    Science.gov (United States)

    Ma, Da; Tian, Shaomin; Baryza, Jeremy; Luft, J Christopher; DeSimone, Joseph M

    2015-10-05

    To achieve the great potential of siRNA based gene therapy, safe and efficient systemic delivery in vivo is essential. Here we report reductively responsive hydrogel nanoparticles with highly uniform size and shape for systemic siRNA delivery in vivo. "Blank" hydrogel nanoparticles with high aspect ratio were prepared using continuous particle fabrication based on PRINT (particle replication in nonwetting templates). Subsequently, siRNA was conjugated to "blank" nanoparticles via a disulfide linker with a high loading ratio of up to 18 wt %, followed by surface modification to enhance transfection. This fabrication process could be easily scaled up to prepare large quantity of hydrogel nanoparticles. By controlling hydrogel composition, surface modification, and siRNA loading ratio, siRNA conjugated nanoparticles were highly tunable to achieve high transfection efficiency in vitro. FVII-siRNA conjugated nanoparticles were further stabilized with surface coating for in vivo siRNA delivery to liver hepatocytes, and successful gene silencing was demonstrated at both mRNA and protein levels.

  8. Purification of crude biodiesel using dry washing and membrane technologies

    Directory of Open Access Journals (Sweden)

    I.M. Atadashi

    2015-12-01

    Full Text Available Purification of crude biodiesel is mandatory for the fuel to meet the strict international standard specifications for biodiesel. Therefore, this paper carefully analyzed recently published literatures which deal with the purification of biodiesel. As such, dry washing technologies and the most recent membrane biodiesel purification process have been thoroughly examined. Although purification of biodiesel using dry washing process involving magnesol and ion exchange resins provides high-quality biodiesel fuel, considerable amount of spent absorbents is recorded, besides the skeletal knowledge on its operating process. Further, recent findings have shown that biodiesel purification using membrane technique could offer high-quality biodiesel fuel with less wastewater discharges. Thus, both researchers and industries are expected to benefit from the development of membrane technique in purifying crude biodiesel. As well biodiesel purification via membranes has been shown to be environmentally friendly. For these reasons, it is important to explore and exploit membrane technology to purify crude biodiesel.

  9. Extraction and purification of yellow cake

    International Nuclear Information System (INIS)

    Yousif, E.H.

    2006-01-01

    This dissertation has reviewed current studies on production and purification of yellow cake from uranium ores by both acid and alkaline leaching processes. It comprises three chapters, the first one deal with uranium minerals, uranium deposits, geology of uranium and uranium isotopes. The second chapter covers mining and milling methods, uranium leaching chemistry, precipitation, and purification of uranium concentrate by solvent extraction and possible impurities that commonly interfered with yellow cake. The last chapter presented ongoing literature review.(Author)

  10. Water Purification

    Science.gov (United States)

    1994-01-01

    The Vision Catalyst Purifier employs the basic technology developed by NASA to purify water aboard the Apollo spacecraft. However, it also uses an "erosion" technique. The purifier kills bacteria, viruses, and algae by "catalytic corrosion." A cartridge contains a silver-impregnated alumina bed with a large surface area. The catalyst bed converts oxygen in a pool of water to its most oxidative state, killing over 99 percent of the bacteria within five seconds. The cartridge also releases into the pool low levels of ionic silver and copper through a controlled process of erosion. Because the water becomes electrochemically active, no electricity is required.

  11. Molybdenum adsorption by alumina and Dowex 1x8 resin for the separation and purification process of fission {sup 99}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Yamaura, M.; Damasceno, M.O.; Freitas, A.A.; Camilo, R.L.; Araujo, I.C.; Forbicini, C.A.L.G. de O., E-mail: myamaura@ipen.b, E-mail: molidam@ipen.b, E-mail: afreitas@ipen.b, E-mail: rcamilo@ipen.b, E-mail: cruz.araujo@uol.com.b, E-mail: cforbici@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Molybdenum-99 is the most widely employed radioisotope in nuclear medicine, due to its decay product, Technetium-99m, a radioisotope used in over 80% of diagnostic tests. Since 2009, the production of generators {sup 99}Mo/{sup 99m}Tc suffers a crisis of global supply. The raw material, the {sup 99}Mo, is produced mainly by fission of {sup 235}U in the reactor in uranium targets. Brazilian government invests in building of a research reactor suitable for the domestic production of {sup 99}Mo from LEU (Low Enriched Uranium) targets and the IPEN/CNEN develops the production technology. This work is part of the research for the development of production technology of {sup 99}Mo at the IPEN/CNEN-SP. The study has evaluated the adsorption behaviour of molybdenum from the alkaline dissolution of aluminum plates by the alumina and by the anionic resin Dowex 1x8 aiming at their use in the process of separation and purification in chromatography columns. Influences of pH and of aluminum concentration in the retention of molybdenum were investigated. Results showed high performance in the wide pH range. However in strongly acid solutions containing aluminum, alumina showed higher adsorption percentage than that achieved by the resin Dowex 1x8. (author)

  12. siRNA delivery with lipid-based systems

    DEFF Research Database (Denmark)

    Foged, Camilla

    2012-01-01

    A key hurdle for the further development of RNA interference (RNAi) therapeutics like small interfering RNA (siRNA) is their safe and effective delivery. Lipids are promising and versatile carriers because they are based on Nature's own building blocks and can be provided with properties which......RNA into more hydrophobic lipoplexes, which promote passage of the siRNA across cellular membrane barriers, especially when lipids are added that facilitate membrane fusion. Despite these attractive features, siRNA delivery vehicles are facing a number of challenges such as the limited delivery efficiency...

  13. Influence of the Reclamation Process Intensity in the REGMAS Reclaimer on the Purification Degree of the High-silica Matrix

    Directory of Open Access Journals (Sweden)

    Skrzyński M.

    2016-03-01

    Full Text Available The investigation results of the reclamation of spent moulding sands with furfuryl resin are presented in this paper. The reclamation process was performed in the secondary reclamation chamber of the REGMAS 1.5 vibratory reclaimer. 70 kg portions of moulding sands, previously subjected to the primary reclamation and dedusting, were used. The secondary reclamation was performed in two stages: the first consisted of determining the reclaimer intensity at various reclamation times (5 min, 10 min and 15 min and various electrovibrator frequencies (40 Hz, 50 Hz and 60 Hz, the second consisted of determining the influence of additional crushing elements on the intensity of processes.

  14. In Silico Design and Experimental Validation of siRNAs Targeting Conserved Regions of Multiple Hepatitis C Virus Genotypes.

    Directory of Open Access Journals (Sweden)

    Mahmoud ElHefnawi

    Full Text Available RNA interference (RNAi is a post-transcriptional gene silencing mechanism that mediates the sequence-specific degradation of targeted RNA and thus provides a tremendous opportunity for development of oligonucleotide-based drugs. Here, we report on the design and validation of small interfering RNAs (siRNAs targeting highly conserved regions of the hepatitis C virus (HCV genome. To aim for therapeutic applications by optimizing the RNAi efficacy and reducing potential side effects, we considered different factors such as target RNA variations, thermodynamics and accessibility of the siRNA and target RNA, and off-target effects. This aim was achieved using an in silico design and selection protocol complemented by an automated MysiRNA-Designer pipeline. The protocol included the design and filtration of siRNAs targeting highly conserved and accessible regions within the HCV internal ribosome entry site, and adjacent core sequences of the viral genome with high-ranking efficacy scores. Off-target analysis excluded siRNAs with potential binding to human mRNAs. Under this strict selection process, two siRNAs (HCV353 and HCV258 were selected based on their predicted high specificity and potency. These siRNAs were tested for antiviral efficacy in HCV genotype 1 and 2 replicon cell lines. Both in silico-designed siRNAs efficiently inhibited HCV RNA replication, even at low concentrations and for short exposure times (24h; they also exceeded the antiviral potencies of reference siRNAs targeting HCV. Furthermore, HCV353 and HCV258 siRNAs also inhibited replication of patient-derived HCV genotype 4 isolates in infected Huh-7 cells. Prolonged treatment of HCV replicon cells with HCV353 did not result in the appearance of escape mutant viruses. Taken together, these results reveal the accuracy and strength of our integrated siRNA design and selection protocols. These protocols could be used to design highly potent and specific RNAi-based therapeutic

  15. The Purification of a Blood Group A Glycoprotein: An Affinity Chromatography Experiment.

    Science.gov (United States)

    Estelrich, J.; Pouplana, R.

    1988-01-01

    Describes a purification process through affinity chromatography necessary to obtain specific blood group glycoproteins from erythrocytic membranes. Discusses the preparation of erythrocytic membranes, extraction of glycoprotein from membranes, affinity chromatography purification, determination of glycoproteins, and results. (CW)

  16. Technological assumptions for biogas purification.

    Science.gov (United States)

    Makareviciene, Violeta; Sendzikiene, Egle

    2015-01-01

    Biogas can be used in the engines of transport vehicles and blended into natural gas networks, but it also requires the removal of carbon dioxide, hydrogen sulphide, and moisture. Biogas purification process flow diagrams have been developed for a process enabling the use of a dolomite suspension, as well as for solutions obtained by the filtration of the suspension, to obtain biogas free of hydrogen sulphide and with a carbon dioxide content that does not exceed 2%. The cost of biogas purification was evaluated on the basis of data on biogas production capacity and biogas production cost obtained from local water treatment facilities. It has been found that, with the use of dolomite suspension, the cost of biogas purification is approximately six times lower than that in the case of using a chemical sorbent such as monoethanolamine. The results showed travelling costs using biogas purified by dolomite suspension are nearly 1.5 time lower than travelling costs using gasoline and slightly lower than travelling costs using mineral diesel fuel.

  17. Purification and partial characterisation of a trypsin from the processing waste of the silver mojarra (Diapterus rhombeus)

    OpenAIRE

    Silva, Janilson F.; Esposito, Talita S.; Marcuschi, Marina; Ribeiro, Karina; Cavalli, Ronaldo O.; Oliveira, Vitor [UNIFESP; Bezerra, Ranilson S.

    2011-01-01

    An alkaline peptidase was purified from the viscera of the silver mojarra (Diapterus rhombeus) in a three-step process: heat treatment, ammonium sulphate fractionation and molecular exclusion chromatography (Sephadex (R) G-75), with final specific activity 86-fold higher than the enzyme extract and yield of 22.1%. the purified enzyme had an estimated molecular mass of 26.5 kDa and NH2-terminal amino acid sequence IVGGYECTMHSEAHE. Higher enzyme activity was observed at pH 8.5 and between 50 an...

  18. Entanglement of purification: from spin chains to holography

    Science.gov (United States)

    Nguyen, Phuc; Devakul, Trithep; Halbasch, Matthew G.; Zaletel, Michael P.; Swingle, Brian

    2018-01-01

    Purification is a powerful technique in quantum physics whereby a mixed quantum state is extended to a pure state on a larger system. This process is not unique, and in systems composed of many degrees of freedom, one natural purification is the one with minimal entanglement. Here we study the entropy of the minimally entangled purification, called the entanglement of purification, in three model systems: an Ising spin chain, conformal field theories holographically dual to Einstein gravity, and random stabilizer tensor networks. We conjecture values for the entanglement of purification in all these models, and we support our conjectures with a variety of numerical and analytical results. We find that such minimally entangled purifications have a number of applications, from enhancing entanglement-based tensor network methods for describing mixed states to elucidating novel aspects of the emergence of geometry from entanglement in the AdS/CFT correspondence.

  19. Transdermal Delivery of siRNA through Microneedle Array

    Science.gov (United States)

    Deng, Yan; Chen, Jiao; Zhao, Yi; Yan, Xiaohui; Zhang, Li; Choy, Kwongwai; Hu, Jun; Sant, Himanshu J.; Gale, Bruce K.; Tang, Tao

    2016-02-01

    Successful development of siRNA therapies has significant potential for the treatment of skin conditions (alopecia, allergic skin diseases, hyperpigmentation, psoriasis, skin cancer, pachyonychia congenital) caused by aberrant gene expression. Although hypodermic needles can be used to effectively deliver siRNA through the stratum corneum, the major challenge is that this approach is painful and the effects are restricted to the injection site. Microneedle arrays may represent a better way to deliver siRNAs across the stratum corneum. In this study, we evaluated for the first time the ability of the solid silicon microneedle array for punching holes to deliver cholesterol-modified housekeeping gene (Gapdh) siRNA to the mouse ear skin. Treating the ear with microneedles showed permeation of siRNA in the skin and could reduce Gapdh gene expression up to 66% in the skin without accumulation in the major organs. The results showed that microneedle arrays could effectively deliver siRNA to relevant regions of the skin noninvasively.

  20. Purification and substrate specificities of a fructanase from Kluyveromyces marxianus isolated from the fermentation process of Mezcal.

    Science.gov (United States)

    Arrizon, Javier; Morel, Sandrine; Gschaedler, Anne; Monsan, Pierre

    2011-02-01

    A fructanase, produced by a Kluyveromyces marxianus strain isolated during the fermentation step of the elaboration process of "Mezcal de Guerrero" was purified and biochemically characterized. The active protein was a glycosylated dimer with a molecular weight of approximately 250 kDa. The specific enzymatic activity of the protein was determined for different substrates: sucrose, inulin, Agave tequilana fructan, levan and Actilight® and compared with the activity of Fructozyme®. The hydrolysis profile of the different substrates analyzed by HPAEC-PAD showed that the enzyme has different affinities over the substrates tested with a sucrose/inulin enzymatic activity ratio (S/I) of 125. For the hydrolysis of Agave tequilana fructans, the enzyme also showed a higher enzymatic activity and specificity than Fructozyme®, which is important for its potential application in the tequila industry. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Purification and partial characterisation of a trypsin from the processing waste of the silver mojarra (Diapterus rhombeus).

    Science.gov (United States)

    Silva, Janilson F; Espósito, Talita S; Marcuschi, Marina; Ribeiro, Karina; Cavalli, Ronaldo O; Oliveira, Vitor; Bezerra, Ranilson S

    2011-12-01

    An alkaline peptidase was purified from the viscera of the silver mojarra (Diapterus rhombeus) in a three-step process: heat treatment, ammonium sulphate fractionation and molecular exclusion chromatography (Sephadex® G-75), with final specific activity 86-fold higher than the enzyme extract and yield of 22.1%. The purified enzyme had an estimated molecular mass of 26.5kDa and NH2-terminal amino acid sequence IVGGYECTMHSEAHE. Higher enzyme activity was observed at pH 8.5 and between 50 and 55°C. The enzyme was completely inactivated after 30min at 55°C and it was significantly more stable at alkaline pH. Km, Kcat and Kcat·Km(-1) values, using BApNA as substrate, were 0.266mM, 0.93s(-1) and 3.48mM(-1)s(-1), respectively. Enzyme activity increased in the presence of the ions (1mM) K(+), Li(+) and Ca(2+), but was inhibited by Fe(2+), Cd(2+), Cu(2+), Al(3+), Hg(2+), Zn(2+) and Pb(2+) as well as by the trypsin inhibitors TLCK and benzamidine. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Chemical composition and molecular structure of polysaccharide-protein biopolymer from Durio zibethinus seed: extraction and purification process

    Directory of Open Access Journals (Sweden)

    Amid Bahareh

    2012-10-01

    Full Text Available Abstract Background The biological functions of natural biopolymers from plant sources depend on their chemical composition and molecular structure. In addition, the extraction and further processing conditions significantly influence the chemical and molecular structure of the plant biopolymer. The main objective of the present study was to characterize the chemical and molecular structure of a natural biopolymer from Durio zibethinus seed. A size-exclusion chromatography coupled to multi angle laser light-scattering (SEC-MALS was applied to analyze the molecular weight (Mw, number average molecular weight (Mn, and polydispersity index (Mw/Mn. Results The most abundant monosaccharide in the carbohydrate composition of durian seed gum were galactose (48.6-59.9%, glucose (37.1-45.1%, arabinose (0.58-3.41%, and xylose (0.3-3.21%. The predominant fatty acid of the lipid fraction from the durian seed gum were palmitic acid (C16:0, palmitoleic acid (C16:1, stearic acid (C18:0, oleic acid (C18:1, linoleic acid (C18:2, and linolenic acid (C18:2. The most abundant amino acids of durian seed gum were: leucine (30.9-37.3%, lysine (6.04-8.36%, aspartic acid (6.10-7.19%, glycine (6.07-7.42%, alanine (5.24-6.14%, glutamic acid (5.57-7.09%, valine (4.5-5.50%, proline (3.87-4.81%, serine (4.39-5.18%, threonine (3.44-6.50%, isoleucine (3.30-4.07%, and phenylalanine (3.11-9.04%. Conclusion The presence of essential amino acids in the chemical structure of durian seed gum reinforces its nutritional value.

  3. Laboratory of minerals purification

    International Nuclear Information System (INIS)

    2002-01-01

    The laboratory of minerals purification was organized in 1962 where with application of modern physical and chemical methods were investigated the mechanism of flotation reagents interaction with minerals' surface, was elaborated technologies on rising complexity of using of republic's minerals

  4. Optimized Reaction Conditions for Removal of Cellular Organic Matter of Microcystis aeruginosa During the Destabilization and Aggregation Process Using Ferric Sulfate in Water Purification

    Czech Academy of Sciences Publication Activity Database

    Pivokonský, Martin; Polášek, Pavel; Pivokonská, Lenka; Tomášková, Hana

    2009-01-01

    Roč. 81, č. 5 (2009), s. 514-522 ISSN 1061-4303 R&D Projects: GA ČR GA103/07/0295 Institutional research plan: CEZ:AV0Z20600510 Keywords : Microcystis aeruginosa * cellular organic matter * destabilization * aggregation * optimized reaction conditions * water purification Subject RIV: BK - Fluid Dynamics Impact factor: 0.965, year: 2009

  5. Venturi purification device and its application in purification of gaseous waste of nuclear facilities

    International Nuclear Information System (INIS)

    Kong Jinsong; Yu Ren; Yang Huanlei

    2013-01-01

    The working principle of Venturi purification device and its purification of aerosol have been described. Then, taking the gaseous iodine as an example, the absorption process of insoluble gas pollutants is discussed, the calculation methods of the gas-liquid contact area, mass transfer rate and efficiency of mass transfer are educed, and the factors that affect the efficiency of mass transfer are analyzed. (authors)

  6. Therapeutic miRNA and siRNA: Moving from Bench to Clinic as Next Generation Medicine

    Directory of Open Access Journals (Sweden)

    Chiranjib Chakraborty

    2017-09-01

    Full Text Available In the past few years, therapeutic microRNA (miRNA and small interfering RNA (siRNA are some of the most important biopharmaceuticals that are in commercial space as future medicines. This review summarizes the patents of miRNA- and siRNA-based new drugs, and also provides a snapshot about significant biopharmaceutical companies that are investing for the therapeutic development of miRNA and siRNA molecules. An insightful view about individual siRNA and miRNA drugs has been depicted with their present status, which is gaining attention in the therapeutic landscape. The efforts of the biopharmaceuticals are discussed with the status of their preclinical and/or clinical trials. Here, some of the setbacks have been highlighted during the biopharmaceutical development of miRNA and siRNA as individual therapeutics. Finally, a snapshot is illustrated about pharmacokinetics, pharmacodynamics with absorption, distribution, metabolism, and excretion (ADME, which is the fundamental development process of these therapeutics, as well as the delivery system for miRNA- and siRNA-based drugs. Keywords: miRNA, siRNA, drug development

  7. Overview of the recombinant proteins purification by affinity tags and ...

    African Journals Online (AJOL)

    From protein within isolation process which the same matter increases labor costs further and prevents application of these tags in industrial scale. Therefore proper replacement is emphasized for enzymatic removal of purification tags. Keywords: protein purification; recombinant proteins; self-cleavable tags; Intein tags; ...

  8. Enrichment of intersubtype HIV-1 recombinants in a dual infection system using HIV-1 strain-specific siRNAs

    Science.gov (United States)

    2011-01-01

    Background Intersubtype HIV-1 recombinants in the form of unique or stable circulating recombinants forms (CRFs) are responsible for over 20% of infections in the worldwide epidemic. Mechanisms controlling the generation, selection, and transmission of these intersubtype HIV-1 recombinants still require further investigation. All intersubtype HIV-1 recombinants are generated and evolve from initial dual infections, but are difficult to identify in the human population. In vitro studies provide the most practical system to study mechanisms, but the recombination rates are usually very low in dual infections with primary HIV-1 isolates. This study describes the use of HIV-1 isolate-specific siRNAs to enrich intersubtype HIV-1 recombinants and inhibit the parental HIV-1 isolates from a dual infection. Results Following a dual infection with subtype A and D primary HIV-1 isolates and two rounds of siRNA treatment, nearly 100% of replicative virus was resistant to a siRNA specific for an upstream target sequence in the subtype A envelope (env) gene as well as a siRNA specific for a downstream target sequence in the subtype D env gene. Only 20% (10/50) of the replicating virus had nucleotide substitutions in the siRNA-target sequence whereas the remaining 78% (39/50) harbored a recombination breakpoint that removed both siRNA target sequences, and rendered the intersubtype D/A recombinant virus resistant to the dual siRNA treatment. Since siRNAs target the newly transcribed HIV-1 mRNA, the siRNAs only enrich intersubtype env recombinants and do not influence the recombination process during reverse transcription. Using this system, a strong bias is selected for recombination breakpoints in the C2 region, whereas other HIV-1 env regions, most notably the hypervariable regions, were nearly devoid of intersubtype recombination breakpoints. Sequence conservation plays an important role in selecting for recombination breakpoints, but the lack of breakpoints in many conserved

  9. MicroRNA-directed siRNA biogenesis in Caenorhabditis elegans.

    Science.gov (United States)

    Corrêa, Régis L; Steiner, Florian A; Berezikov, Eugene; Ketting, René F

    2010-04-08

    RNA interference (RNAi) is a post-transcriptional silencing process, triggered by double-stranded RNA (dsRNA), leading to the destabilization of homologous mRNAs. A distinction has been made between endogenous RNAi-related pathways and the exogenous RNAi pathway, the latter being essential for the experimental use of RNAi. Previous studies have shown that, in Caenorhabditis elegans, a complex containing the enzymes Dicer and the Argonaute RDE-1 process dsRNA. Dicer is responsible for cleaving dsRNA into short interfering RNAs (siRNAs) while RDE-1 acts as the siRNA acceptor. RDE-1 then guides a multi-protein complex to homologous targets to trigger mRNA destabilization. However, endogenous role(s) for RDE-1, if any, have remained unexplored. We here show that RDE-1 functions as a scavenger protein, taking up small RNA molecules from many different sources, including the microRNA (miRNA) pathway. This is in striking contrast to Argonaute proteins functioning directly in the miRNA pathway, ALG-1 and ALG-2: these proteins exclusively bind miRNAs. While playing no significant role in the biogenesis of the main pool of miRNAs, RDE-1 binds endogenous miRNAs and triggers RdRP activity on at least one perfectly matching, endogenous miRNA target. The resulting secondary siRNAs are taken up by a set of Argonaute proteins known to act as siRNA acceptors in exogenous RNAi, resulting in strong mRNA destabilization. Our results show that RDE-1 in an endogenous setting is actively screening the transcriptome using many different small RNAs, including miRNAs, as a guide, with implications for the evolution of transcripts with a potential to be recognized by Dicer.

  10. MicroRNA–Directed siRNA Biogenesis in Caenorhabditis elegans

    Science.gov (United States)

    Corrêa, Régis L.; Steiner, Florian A.; Berezikov, Eugene; Ketting, René F.

    2010-01-01

    RNA interference (RNAi) is a post-transcriptional silencing process, triggered by double-stranded RNA (dsRNA), leading to the destabilization of homologous mRNAs. A distinction has been made between endogenous RNAi–related pathways and the exogenous RNAi pathway, the latter being essential for the experimental use of RNAi. Previous studies have shown that, in Caenorhabditis elegans, a complex containing the enzymes Dicer and the Argonaute RDE-1 process dsRNA. Dicer is responsible for cleaving dsRNA into short interfering RNAs (siRNAs) while RDE-1 acts as the siRNA acceptor. RDE-1 then guides a multi-protein complex to homologous targets to trigger mRNA destabilization. However, endogenous role(s) for RDE-1, if any, have remained unexplored. We here show that RDE-1 functions as a scavenger protein, taking up small RNA molecules from many different sources, including the microRNA (miRNA) pathway. This is in striking contrast to Argonaute proteins functioning directly in the miRNA pathway, ALG-1 and ALG-2: these proteins exclusively bind miRNAs. While playing no significant role in the biogenesis of the main pool of miRNAs, RDE-1 binds endogenous miRNAs and triggers RdRP activity on at least one perfectly matching, endogenous miRNA target. The resulting secondary siRNAs are taken up by a set of Argonaute proteins known to act as siRNA acceptors in exogenous RNAi, resulting in strong mRNA destabilization. Our results show that RDE-1 in an endogenous setting is actively screening the transcriptome using many different small RNAs, including miRNAs, as a guide, with implications for the evolution of transcripts with a potential to be recognized by Dicer. PMID:20386745

  11. Solvent-extraction purification of neptunium

    International Nuclear Information System (INIS)

    Kyser, E.A.; Hudlow, S.L.

    2008-01-01

    The Savannah River Site (SRS) has recovered 237 Np from reactor fuel that is currently being processed into NpO 2 for future production of 238 Pu. Several purification flowsheets have been utilized. An oxidizing solvent-extraction (SX) flowsheet was used to remove Fe, sulfate ion, and Th while simultaneously 237 Np, 238 Pu, u, and nonradioactive Ce(IV) was extracted into the tributyl phosphate (TBP) based organic solvent. A reducing SX flowsheet (second pass) removed the Ce and Pu and recovered both Np and U. The oxidizing flowsheet was necessary for solutions that contained excessive amounts of sulfate ion. Anion exchange was used to perform final purification of Np from Pu, U, and various non-actinide impurities. The Np(IV) in the purified solution was then oxalate-precipitated and calcined to an oxide for shipment to other facilities for storage and future target fabrication. Performance details of the SX purification and process difficulties are discussed. (authors)

  12. New insights into siRNA amplification and RNAi.

    Science.gov (United States)

    Zhang, Chi; Ruvkun, Gary

    2012-08-01

    In the nematode Caenorhabditis elegans (C. elegans), gene inactivation by RNA interference can achieve remarkable potency due to the amplification of initial silencing triggers by RNA-dependent RNA polymerases (RdRPs). RdRPs catalyze the biogenesis of an abundant species of secondary small interfering RNAs (siRNAs) using the target mRNA as template. The interaction between primary siRNAs derived from the exogenous double-stranded RNA (dsRNA) trigger and the target mRNA is required for the recruitment of RdRPs. Other genetic requirements for RdRP activities have not been characterized. Recent studies have identified the RDE-10/RDE-11 complex which interacts with the primary siRNA bound target mRNA and acts upstream of the RdRPs. rde-10 and rde-11 mutants show an RNAi defective phenotype because the biogenesis of secondary siRNAs is completely abolished. In addition, the RDE-10/RDE-11 complex plays a similar role in the endogenous RNAi pathway for the biogenesis of a subset of siRNAs targeting recently acquired, duplicated genes.

  13. Efficient and gentle siRNA delivery by magnetofection

    Science.gov (United States)

    Ensenauer, R; Hartl, D; Vockley, J; Roscher, AA; Fuchs, U

    2015-01-01

    Magnetic force combined with magnetic nanoparticles recently has shown potential for enhancing nucleic acid delivery. Achieving effective siRNA delivery into primary cultured cells is challenging. We compared the utility of magnetofection with lipofection procedures for siRNA delivery to primary and immortalized mammalian fibroblasts. Transfection efficiency and cell viability were analyzed by flow cytometry and effects of gene knockdown were quantified by real-time PCR. Lipofectamine 2000 and magnetofection achieved high transfection efficiencies comparable to similar gene silencing effects of about 80%; the cytotoxic effect of magnetofection, however, was significantly less. Magnetofection is a reliable and gentle alternative method with low cytotoxicity for siRNA delivery into difficult to transfect cells such as mammalian fibroblasts. These features are especially advantageous for functional end point analyses of gene silencing, e.g., on the metabolite level. PMID:20297946

  14. Targeted Delivery of siRNA Therapeutics to Malignant Tumors

    Directory of Open Access Journals (Sweden)

    Qixin Leng

    2017-01-01

    Full Text Available Over the past 20 years, a diverse group of ligands targeting surface biomarkers or receptors has been identified with several investigated to target siRNA to tumors. Many approaches to developing tumor-homing peptides, RNA and DNA aptamers, and single-chain variable fragment antibodies by using phage display, in vitro evolution, and recombinant antibody methods could not have been imagined by researchers in the 1980s. Despite these many scientific advances, there is no reason to expect that the ligand field will not continue to evolve. From development of ligands based on novel or existing biomarkers to linking ligands to drugs and gene and antisense delivery systems, several fields have coalesced to facilitate ligand-directed siRNA therapeutics. In this review, we discuss the major categories of ligand-targeted siRNA therapeutics for tumors, as well as the different strategies to identify new ligands.

  15. Synthesis of two new alkyne-bearing linkers used for the preparation of siRNA for labeling by click chemistry with fluorine-18

    International Nuclear Information System (INIS)

    Flagothier, Jessica; Kaisin, Geoffroy; Mercier, Frederic; Thonon, David; Teller, Nathalie; Wouters, Johan; Luxen, André

    2012-01-01

    Oligonucleotides (ONs) and more particularly siRNAs are promising drugs but their pharmacokinetics and biodistribution are widely unknown. Positron Emission Tomography (PET) using fluorine-18 is a suitable technique to quantify these biological processes. Click chemistry (Huisgen cycloaddition) is the current method for labeling siRNA. In order to study the influence of a linker bearing by [ 18 F] labeled ONs, on the in vivo pharmacokinetic and metabolism, we have developed two modified ONs by two new linkers. Here we report the synthesis of two alkyne-bearing linkers, the incorporation onto a ONs and the conjugation by click chemistry with a [ 18 F] prosthetic group. - Highlights: ► Synthesis of two new alkyne linkers. ► Functionalization at the 3′-end siRNA by alkyne linker derived of proline. ► Click chemistry between alkyne modified siRNA and [ 18 F] prosthetic group.

  16. Synthesis of PLGA-Lipid Hybrid Nanoparticles for siRNA Delivery Using the Emulsion Method PLGA-PEG-Lipid Nanoparticles for siRNA Delivery.

    Science.gov (United States)

    Wang, Lei; Griffel, Benjamin; Xu, Xiaoyang

    2017-01-01

    The effective delivery of small interfering RNA (siRNA) to tumor cells remains a challenge for applications in cancer therapy. The development of polymeric nanoparticles with high siRNA loading efficacy has shown great potential for cancer targets. Double emulsion solvent evaporation technique is a useful tool for encapsulation of hydrophilic molecules (e.g., siRNA). Here we describe a versatile platform for siRNA delivery based on PLGA-PEG-cationic lipid nanoparticles by using the double emulsion method. The resulting nanoparticles show high encapsulation efficiency for siRNA (up to 90%) and demonstrate effective downregulation of the target genes in vitro and vivo.

  17. Dicer-like 3 produces transposable element-associated 24-nt siRNAs that control agricultural traits in rice

    Science.gov (United States)

    Wei, Liya; Gu, Lianfeng; Song, Xianwei; Cui, Xiekui; Lu, Zhike; Zhou, Ming; Wang, Lulu; Hu, Fengyi; Zhai, Jixian; Meyers, Blake C.; Cao, Xiaofeng

    2014-01-01

    Transposable elements (TEs) and repetitive sequences make up over 35% of the rice (Oryza sativa) genome. The host regulates the activity of different TEs by different epigenetic mechanisms, including DNA methylation, histone H3K9 methylation, and histone H3K4 demethylation. TEs can also affect the expression of host genes. For example, miniature inverted repeat TEs (MITEs), dispersed high copy-number DNA TEs, can influence the expression of nearby genes. In plants, 24-nt small interfering RNAs (siRNAs) are mainly derived from repeats and TEs. However, the extent to which TEs, particularly MITEs associated with 24-nt siRNAs, affect gene expression remains elusive. Here, we show that the rice Dicer-like 3 homolog OsDCL3a is primarily responsible for 24-nt siRNA processing. Impairing OsDCL3a expression by RNA interference caused phenotypes affecting important agricultural traits; these phenotypes include dwarfism, larger flag leaf angle, and fewer secondary branches. We used small RNA deep sequencing to identify 535,054 24-nt siRNA clusters. Of these clusters, ∼82% were OsDCL3a-dependent and showed significant enrichment of MITEs. Reduction of OsDCL3a function reduced the 24-nt siRNAs predominantly from MITEs and elevated expression of nearby genes. OsDCL3a directly targets genes involved in gibberellin and brassinosteroid homeostasis; OsDCL3a deficiency may affect these genes, thus causing the phenotypes of dwarfism and enlarged flag leaf angle. Our work identifies OsDCL3a-dependent 24-nt siRNAs derived from MITEs as broadly functioning regulators for fine-tuning gene expression, which may reflect a conserved epigenetic mechanism in higher plants with genomes rich in dispersed repeats or TEs. PMID:24554078

  18. High loading efficiency and sustained release of siRNA encapsulated in PLGA nanoparticles: quality by design optimization and characterization.

    Science.gov (United States)

    Cun, Dongmei; Jensen, Ditte Krohn; Maltesen, Morten Jonas; Bunker, Matthew; Whiteside, Paul; Scurr, David; Foged, Camilla; Nielsen, Hanne Mørck

    2011-01-01

    Poly(DL-lactide-co-glycolide acid) (PLGA) is an attractive polymer for delivery of biopharmaceuticals owing to its biocompatibility, biodegradability and outstanding controlled release characteristics. The purpose of this study was to understand and define optimal parameters for preparation of small interfering RNA (siRNA)-loaded PLGA nanoparticles by the double emulsion solvent evaporation method and characterize their properties. The experiments were performed according to a 2(5-1) fractional factorial design based on five independent variables: The volume ratio between the inner water phase and the oil phase, the PLGA concentration, the sonication time, the siRNA load and the amount of acetylated bovine serum albumin (Ac-BSA) in the inner water phase added to stabilize the primary emulsion. The effects on the siRNA encapsulation efficiency and the particle size were investigated. The most important factors for obtaining an encapsulation efficiency as high as 70% were the PLGA concentration and the volume ratio whereas the size was mainly affected by the PLGA concentration. The viscosity of the oil phase was increased at high PLGA concentration, which explains the improved encapsulation by stabilization of the primary emulsion and reduction of siRNA leakage to the outer water phase. Addition of Ac-BSA increased the encapsulation efficiency at low PLGA concentrations. The PLGA matrix protected siRNA against nuclease degradation, provided a burst release of surface-localized siRNA followed by a triphasic sustained release for two months. These results enable careful understanding and definition of optimal process parameters for preparation of PLGA nanoparticles encapsulating high amounts of siRNA with immediate and long-term sustained release properties. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. Albumin-mediated delivery of siRNA

    DEFF Research Database (Denmark)

    Bienk, Konrad

    2015-01-01

    . The human body, however, possesses several natural transport mechanisms for active transport of molecules. Amongst these is albumin, which is the most abundant plasma protein and has a circulatory half-life of ~21 days, partially due to engagement and recycling by the neonatal Fc receptor (FcRn). Albumin...... vehicle. This proof of concept silencing showed that siRNA can be used for therapeutic purposes without the use of non-biocompatible polymer or lipid materials. This work, therefore, provides a novel technology platform for the safe delivery of siRNA therapeutics....

  20. Solvent purification using a current of water vapour. A continuous process applicable to chemical plants treating irradiated fuels; Purification des solvants par entrainement a la vapeur d'eau. Procede continu applicable aux usines chimiques de traitement des combustibles irradies

    Energy Technology Data Exchange (ETDEWEB)

    Auchapt, P R; Sautray, R R; Girard, B R [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1964-07-01

    The pilot plant described in this report is intended for the continuous purification of the solvent used in the plutonium extraction plant at Marcoule, by separating the impurities (fission products). This physical separation is operated by carrying over in a water vapour stream. The contaminating products, only slightly volatile, remain in the form of the droplets and are separated; the vaporised solvent and the water vapour used are condensed and then separated. The originality of the installation resides in the system for pulverising the liquid and in the operating conditions: low working pressure and temperature. The systematic analysis of the various parameters (percentage of residue; flow, pressure and temperature ratios etc...) has shown their influence on the decontamination. The activity due to the zirconium-niobium is undetectable after treatment, and it is easy to obtain decontamination factors of 300 for the ruthenium. The, presence of uranium is favorable for the decontamination. As a conclusion, some extra-technical considerations are given concerning in particular the approximate cost price of the treated solvent per litre. (authors) [French] L'installation pilote decrite dans ce rapport est destinee a purifier, en continu, le solvant utilise a l'usine d'extraction du plutonium de Marcoule, en separant les impuretes (produits de fission). Cette separation physique est realisee par entrainement a la vapeur d'eau. Les produits contaminants, peu volatils, restant sous forme de gouttelettes, sont separes; le solvant vaporise ainsi que la vapeur d'entrainement sont condenses puis separes. L'originalite de l'installation reside dans le systeme de pulverisation du liquide et dans les conditions operatoires: faible pression et basse temperature de fonctionnement. L'analyse systematique des differents parametres (pourcentage de residus, rapport de debits, pression et temperature, etc...) a mis en evidence leur influence sur la decontamination. L'activite en

  1. Cadmium purification with a vibrating reactor

    International Nuclear Information System (INIS)

    Torres, N.; Esna-Ashari, M.; Biallas, H.; Kangas, K.

    1986-01-01

    While electrolytically producing zinc from sulfide concentrates, purification is the most significant step. Impurities such as Co, Sn, Ge, Ni and Sb can cause extensive redissolution of the electrodeposited zinc, thus diminishing current efficiency. Other metals, particularly cadmium, lead and copper, can negatively affect zinc properties by deposition on the cathode. It is standard practice to use atomized zinc dust as a reducing agent in the purification process, either alone or combined with additives. In conventional operations, special facilities are necessary to produce zinc dust in an amount close to 8wt% of cathode production. This paper examines a technique which makes use of zinc granules instead of dust

  2. Partial purification and biochemical characterization of acid ...

    African Journals Online (AJOL)

    Mung bean (Vigna radiata) is one of the important crops of the North Eastern Region of India. In the present study, acid phosphatase enzyme was isolated and partially purified from germinated local mung bean seeds. The sequential partial purification process was performed using ammonium sulphate precipitation method.

  3. Improved nucleic acid descriptors for siRNA efficacy prediction.

    Science.gov (United States)

    Sciabola, Simone; Cao, Qing; Orozco, Modesto; Faustino, Ignacio; Stanton, Robert V

    2013-02-01

    Although considerable progress has been made recently in understanding how gene silencing is mediated by the RNAi pathway, the rational design of effective sequences is still a challenging task. In this article, we demonstrate that including three-dimensional descriptors improved the discrimination between active and inactive small interfering RNAs (siRNAs) in a statistical model. Five descriptor types were used: (i) nucleotide position along the siRNA sequence, (ii) nucleotide composition in terms of presence/absence of specific combinations of di- and trinucleotides, (iii) nucleotide interactions by means of a modified auto- and cross-covariance function, (iv) nucleotide thermodynamic stability derived by the nearest neighbor model representation and (v) nucleic acid structure flexibility. The duplex flexibility descriptors are derived from extended molecular dynamics simulations, which are able to describe the sequence-dependent elastic properties of RNA duplexes, even for non-standard oligonucleotides. The matrix of descriptors was analysed using three statistical packages in R (partial least squares, random forest, and support vector machine), and the most predictive model was implemented in a modeling tool we have made publicly available through SourceForge. Our implementation of new RNA descriptors coupled with appropriate statistical algorithms resulted in improved model performance for the selection of siRNA candidates when compared with publicly available siRNA prediction tools and previously published test sets. Additional validation studies based on in-house RNA interference projects confirmed the robustness of the scoring procedure in prospective studies.

  4. Sodium purification in Rapsodie

    International Nuclear Information System (INIS)

    Giraud, B.

    1968-01-01

    This report is one of a series of publications presenting the main results of tests carried out during the start-up of the first french fast neutron reactor: Rapsodie. The article presents the sodium purification techniques used in the reactor cooling circuits both from the constructional point of view and with respect to results obtained during the first years working. (author) [fr

  5. Overcoming the Challenges of siRNA Delivery: Nanoparticle Strategies.

    Science.gov (United States)

    Shajari, Neda; Mansoori, Behzad; Davudian, Sadaf; Mohammadi, Ali; Baradaran, Behzad

    2017-01-01

    Despite therapeutics based on siRNA have an immense potential for the treatment of incurable diseases such as cancers. However, the in vivo utilization of siRNA and also the delivery of this agent to the target site is one of the most controversial challenges. The helpful assistance by nanoparticles can improve stable delivery and also enhance efficacy. More nanoparticle-based siRNA therapeutics is expected to become available in the near future. The search strategy followed the guidelines of the Centre of Reviews and Dissemination. The studies were identified from seven databases (Scopus, Web of Science, Academic Search Premiere, CINAHL, Medline Ovid, Eric and Cochrane Library). Studies was selected based on titles, abstracts and full texts. One hundred twenty nine papers were included in the review. These papers defined hurdles in RNAi delivery and also strategies to overcome these hurdles. This review discussed the existing hurdles for systemic administration of siRNA as therapeutic agents and highlights the various strategies to overcome these hurdles, including lipid-based nanoparticles and polymeric nanoparticles, and we also briefly reviewed chemical modification. Delivery of siRNA to the target site is the biggest challenge for its application in the clinic. The findings of this review confirmed by encapsulation siRNA in the nanoparticles can overcome these challenges. The rapid progress in nanotechnology has enabled the development of effective nanoparticles as the carrier for siRNA delivery. However, our data about siRNA-based therapeutics and also nanomedicine are still limited. More clinical data needs to be completely understood in the benefits and drawbacks of siRNA-based therapeutics. Prospective studies must pay attention to the in vivo safety profiles of the different delivery systems, including uninvited immune system stimulation and cytotoxicity. In essence, the development of nontoxic, biocompatible, and biodegradable delivery systems for

  6. A surface-mediated siRNA delivery system developed with chitosan/hyaluronic acid-siRNA multilayer films through layer-by-layer self-assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Lijuan [Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062 (China); Suzhou Novovita Bio-products Co., Ltd., Suzhou 215300 (China); Wu, Changlin, E-mail: Ph.Dclwu1314@sina.cn [Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062 (China); Suzhou Novovita Bio-products Co., Ltd., Suzhou 215300 (China); Liu, Guangwan [Suzhou Novovita Bio-products Co., Ltd., Suzhou 215300 (China); Liao, Nannan [Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062 (China); Suzhou Novovita Bio-products Co., Ltd., Suzhou 215300 (China); Zhao, Fang; Yang, Xuxia; Qu, Hongyuan [Suzhou Novovita Bio-products Co., Ltd., Suzhou 215300 (China); Peng, Bo [Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062 (China); Chen, Li [Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062 (China); Suzhou Novovita Bio-products Co., Ltd., Suzhou 215300 (China); Yang, Guang [Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062 (China)

    2016-12-15

    Highlights: • We prepared Chitosan/Hyaluronic acid-siRNA multilayer as carrier to effectively load and protect siRNAs. • The stability and integrity of the siRNA was verified in the siRNA-loaded films. • The siRNA-loaded films showed good cells adhesion and gene silencing effect in eGFP-HEK 293T cells. • This is a new type of surface-mediated non-viral multilayer films. - Abstract: siRNA delivery remains highly challenging because of its hydrophilic and anionic nature and its sensitivity to nuclease degradation. Effective siRNA loading and improved transfection efficiency into cells represents a key problem. In our study, we prepared Chitosan/Hyaluronic acid-siRNA multilayer films through layer-by-layer self-assembly, in which siRNAs can be effectively loaded and protected. The construction process was characterized by FTIR, {sup 13}C NMR (CP/MAS), UV–vis spectroscopy, and atomic force microscopy (AFM). We presented the controlled-release performance of the films during incubation in 1 M NaCl solution for several days through UV–vis spectroscopy and polyacrylamide gel electrophoresis (PAGE). Additionally, we verified the stability and integrity of the siRNA loaded on multilayer films. Finally, the biological efficacy of the siRNA delivery system was evaluated via cells adhesion and gene silencing analyses in eGFP-HEK 293T cells. This new type of surface-mediated non-viral multilayer films may have considerable potential in the localized and controlled-release delivery of siRNA in mucosal tissues, and tissue engineering application.

  7. The modification of siRNA with 3' cholesterol to increase nuclease protection and suppression of native mRNA by select siRNA polyplexes.

    Science.gov (United States)

    Ambardekar, Vishakha V; Han, Huai-Yun; Varney, Michelle L; Vinogradov, Serguei V; Singh, Rakesh K; Vetro, Joseph A

    2011-02-01

    Polymer-siRNA complexes (siRNA polyplexes) are being actively developed to improve the therapeutic application of siRNA. A major limitation for many siRNA polyplexes, however, is insufficient mRNA suppression. Given that modifying the sense strand of siRNA with 3' cholesterol (chol-siRNA) increases the activity of free nuclease-resistant siRNA in vitro and in vivo, we hypothesized that complexation of chol-siRNA can increase mRNA suppression by siRNA polyplexes. In this study, the characteristics and siRNA activity of self assembled polyplexes formed with chol-siRNA or unmodified siRNA were compared using three types of conventional, positively charged polymers: (i) biodegradable, cross-linked nanogels (BDNG) (ii) graft copolymers (PEI-PEG), and (iii) linear block copolymers (PLL10-PEG, and PLL50-PEG). Chol-siRNA did not alter complex formation or the resistance of polyplexes to siRNA displacement by heparin but increased nuclease protection by BDNG, PLL10-PEG, and PLL50-PEG polyplexes over polyplexes with unmodified siRNA. Chol-CYPB siRNA increased suppression of native CYPB mRNA in mammary microvascular endothelial cells (MVEC) by BDNG polyplexes (35%) and PLL10-PEG polyplexes (69%) over comparable CYPB siRNA polyplexes but had no effect on PEI-PEG or PLL50-PEG polyplexes. Overall, these results indicate that complexation of chol-siRNA increases nuclease protection and mRNA suppression by select siRNA polyplexes. These results also suggest that polycationic block length is an important factor in increasing mRNA suppression by PLL-PEG chol-siRNA polyplexes in mammary MVEC. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. The Modification of siRNA with 3′ Cholesterol to Increase Nuclease Protection and Suppression of Native mRNA by Select siRNA Polyplexes

    Science.gov (United States)

    Ambardekar, Vishakha V.; Han, Huai-Yun; Varney, Michelle L.; Vinogradov, Serguei V.; Singh, Rakesh K.; Vetro, Joseph A.

    2010-01-01

    Polymer-siRNA complexes (siRNA polyplexes) are being actively developed to improve the therapeutic application of siRNA. A major limitation for many siRNA polyplexes, however, is insufficient mRNA suppression. Given that modifying the sense strand of siRNA with 3′ cholesterol (chol-siRNA) increases the activity of free nuclease-resistant siRNA in vitro and in vivo, we hypothesized that complexation of chol-siRNA can increase mRNA suppression by siRNA polyplexes. In this study, the characteristics and siRNA activity of self assembled polyplexes formed with chol-siRNA or unmodified siRNA were compared using three types of conventional, positively charged polymers: (i) biodegradable, cross-linked nanogels (BDNG) (ii) graft copolymers (PEI-PEG), and (iii) linear block copolymers (PLL10-PEG, and PLL50-PEG). Chol-siRNA did not alter complex formation or the resistance of polyplexes to siRNA displacement by heparin but increased nuclease protection by BDNG, PLL10-PEG, and PLL50-PEG polyplexes over polyplexes with unmodified siRNA. Chol-CYPB siRNA increased suppression of native CYPB mRNA in mammary microvascular endothelial cells (MVEC) by BDNG polyplexes (35%) and PLL10-PEG polyplexes (69%) over comparable CYPB siRNA polyplexes but had no effect on PEI-PEG or PLL50-PEG polyplexes. Overall, these results indicate that complexation of chol-siRNA increases nuclease protection and mRNA suppression by select siRNA polyplexes. These results also suggest that polycationic block length is an important factor in increasing mRNA suppression by PLL-PEG chol-siRNA polyplexes in mammary MVEC. PMID:21047680

  9. Efficient construction of an inverted minimal H1 promoter driven siRNA expression cassette: facilitation of promoter and siRNA sequence exchange.

    Directory of Open Access Journals (Sweden)

    Hoorig Nassanian

    2007-08-01

    Full Text Available RNA interference (RNAi, mediated by small interfering RNA (siRNA, is an effective method used to silence gene expression at the post-transcriptional level. Upon introduction into target cells, siRNAs incorporate into the RNA-induced silencing complex (RISC. The antisense strand of the siRNA duplex then "guides" the RISC to the homologous mRNA, leading to target degradation and gene silencing. In recent years, various vector-based siRNA expression systems have been developed which utilize opposing polymerase III promoters to independently drive expression of the sense and antisense strands of the siRNA duplex from the same template.We show here the use of a ligase chain reaction (LCR to develop a new vector system called pInv-H1 in which a DNA sequence encoding a specific siRNA is placed between two inverted minimal human H1 promoters (approximately 100 bp each. Expression of functional siRNAs from this construct has led to efficient silencing of both reporter and endogenous genes. Furthermore, the inverted H1 promoter-siRNA expression cassette was used to generate a retrovirus vector capable of transducing and silencing expression of the targeted protein by>80% in target cells.The unique design of this construct allows for the efficient exchange of siRNA sequences by the directional cloning of short oligonucleotides via asymmetric restriction sites. This provides a convenient way to test the functionality of different siRNA sequences. Delivery of the siRNA cassette by retroviral transduction suggests that a single copy of the siRNA expression cassette efficiently knocks down gene expression at the protein level. We note that this vector system can potentially be used to generate a random siRNA library. The flexibility of the ligase chain reaction suggests that additional control elements can easily be introduced into this siRNA expression cassette.

  10. Health physics system scheme for the uranium purification plant

    International Nuclear Information System (INIS)

    Meyer, M.; Oliveira, E.C.; Sordi, G.A.A.; Abrao, A.

    1976-01-01

    After describing the two uranium purification processes used in the Chemical Engineerring Division of the Instituto de Energia Atomica, it is examined the possible hazards and methods to control or eliminate them. Since these purification process present several stages, in each one of them it is evaluated the hazards and tried to give adequate solutions to protect both, personnel and installations, from the potential radiation hazards

  11. Design of an inhalable dry powder formulation of DOTAP-modified PLGA nanoparticles loaded with siRNA.

    Science.gov (United States)

    Jensen, Ditte Krohn; Jensen, Linda Boye; Koocheki, Saeid; Bengtson, Lasse; Cun, Dongmei; Nielsen, Hanne Mørck; Foged, Camilla

    2012-01-10

    Matrix systems based on biocompatible and biodegradable polymers like the United States Food and Drug Administration (FDA)-approved polymer poly(DL-lactide-co-glycolide acid) (PLGA) are promising for the delivery of small interfering RNA (siRNA) due to favorable safety profiles, sustained release properties and improved colloidal stability, as compared to polyplexes. The purpose of this study was to design a dry powder formulation based on cationic lipid-modified PLGA nanoparticles intended for treatment of severe lung diseases by pulmonary delivery of siRNA. The cationic lipid dioleoyltrimethylammoniumpropane (DOTAP) was incorporated into the PLGA matrix to potentiate the gene silencing efficiency. The gene knock-down level in vitro was positively correlated to the weight ratio of DOTAP in the particles, and 73% silencing was achieved in the presence of 10% (v/v) serum at 25% (w/w) DOTAP. Optimal properties were found for nanoparticles modified with 15% (w/w) DOTAP, which reduced the gene expression with 54%. This formulation was spray-dried with mannitol into nanocomposite microparticles of an aerodynamic size appropriate for lung deposition. The spray-drying process did not affect the physicochemical properties of the readily re-dispersible nanoparticles, and most importantly, the in vitro gene silencing activity was preserved during spray-drying. The siRNA content in the powder was similar to the theoretical loading and the siRNA was intact, suggesting that the siRNA is preserved during the spray-drying process. Finally, X-ray powder diffraction analysis demonstrated that mannitol remained in a crystalline state upon spray-drying with PLGA nanoparticles suggesting that the sugar excipient might exert its stabilizing effect by sterical inhibition of the interactions between adjacent nanoparticles. This study demonstrates that spray-drying is an excellent technique for engineering dry powder formulations of siRNA nanoparticles, which might enable the local

  12. Ash study for biogas purification

    International Nuclear Information System (INIS)

    Juarez V, R. I.

    2016-01-01

    This work evaluates the ashes generated from the wood and coal combustion process of the thermoelectric plant in Petacalco, Guerrero (Mexico) in order to determine its viability as a filter in the biogas purification process. The ash is constituted by particles of morphology and different chemical properties, so it required a characterization of the same by different analytical techniques: as was scanning electron microscopy and X-ray diffraction, in order to observe the microstructure and determine the elemental chemical composition of the particles. Prior to the analysis, a set of sieves was selected to classify as a function of particle size. Four different types of ashes were evaluated: one generated by the wood combustion (wood ash) and three more of the Petacalco thermoelectric generated by the coal combustion (wet fly ash, dry fly ash and dry bottom ash). (Author)

  13. Polyether sulfone/hydroxyapatite mixed matrix membranes for protein purification

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Junfen, E-mail: junfensun@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, North People Road 2999, Shanghai 201620 (China); Wu, Lishun [Department of Chemistry and Chemical Engineering, Heze University, Daxue Road 2269, Heze, Shandong Province 274015 (China)

    2014-07-01

    This work proposes a novel approach for protein purification from solution using mixed matrix membranes (MMMs) comprising of hydroxyapatite (HAP) inside polyether sulfone (PES) matrix. The influence of HAP particle loading on membrane morphology is studied. The MMMs are further characterized concerning permeability and adsorption capacity. The MMMs show purification of protein via both diffusion as well as adsorption, and show the potential of using MMMs for improvements in protein purification techniques. The bovine serum albumin (BSA) was used as a model protein. The properties and structures of MMMs prepared by immersion phase separation process were characterized by pure water flux, BSA adsorption and scanning electron microscopy (SEM).

  14. Effective gene silencing activity of prodrug-type 2'-O-methyldithiomethyl siRNA compared with non-prodrug-type 2'-O-methyl siRNA.

    Science.gov (United States)

    Hayashi, Junsuke; Nishigaki, Misa; Ochi, Yosuke; Wada, Shun-Ichi; Wada, Fumito; Nakagawa, Osamu; Obika, Satoshi; Harada-Shiba, Mariko; Urata, Hidehito

    2018-07-01

    Small interfering RNAs (siRNAs) are an active agent to induce gene silencing and they have been studied for becoming a biological and therapeutic tool. Various 2'-O-modified RNAs have been extensively studied to improve the nuclease resistance. However, the 2'-O-modified siRNA activities were often decreased by modification, since the bulky 2'-O-modifications inhibit to form a RNA-induced silencing complex (RISC). We developed novel prodrug-type 2'-O-methyldithiomethyl (MDTM) siRNA, which is converted into natural siRNA in an intracellular reducing environment. Prodrug-type 2'-O-MDTM siRNAs modified at the 5'-end side including 5'-end nucleotide and the seed region of the antisense strand exhibited much stronger gene silencing effect than non-prodrug-type 2'-O-methyl (2'-O-Me) siRNAs. Furthermore, the resistances for nuclease digestion of siRNAs were actually enhanced by 2'-O-MDTM modifications. Our results indicate that 2'-O-MDTM modifications improve the stability of siRNA in serum and they are able to be introduced at any positions of siRNA. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. A framework for multiple kernel support vector regression and its applications to siRNA efficacy prediction.

    Science.gov (United States)

    Qiu, Shibin; Lane, Terran

    2009-01-01

    The cell defense mechanism of RNA interference has applications in gene function analysis and promising potentials in human disease therapy. To effectively silence a target gene, it is desirable to select appropriate initiator siRNA molecules having satisfactory silencing capabilities. Computational prediction for silencing efficacy of siRNAs can assist this screening process before using them in biological experiments. String kernel functions, which operate directly on the string objects representing siRNAs and target mRNAs, have been applied to support vector regression for the prediction and improved accuracy over numerical kernels in multidimensional vector spaces constructed from descriptors of siRNA design rules. To fully utilize information provided by string and numerical data, we propose to unify the two in a kernel feature space by devising a multiple kernel regression framework where a linear combination of the kernels is used. We formulate the multiple kernel learning into a quadratically constrained quadratic programming (QCQP) problem, which although yields global optimal solution, is computationally demanding and requires a commercial solver package. We further propose three heuristics based on the principle of kernel-target alignment and predictive accuracy. Empirical results demonstrate that multiple kernel regression can improve accuracy, decrease model complexity by reducing the number of support vectors, and speed up computational performance dramatically. In addition, multiple kernel regression evaluates the importance of constituent kernels, which for the siRNA efficacy prediction problem, compares the relative significance of the design rules. Finally, we give insights into the multiple kernel regression mechanism and point out possible extensions.

  16. Neuroprotection by biodegradable PAMAM ester (e-PAM-R)-mediated HMGB1 siRNA delivery in primary cortical cultures and in the postischemic brain.

    Science.gov (United States)

    Kim, Il-Doo; Lim, Chae-Moon; Kim, Jung-Bin; Nam, Hye Yeong; Nam, Kihoon; Kim, Seung-Woo; Park, Jong-Sang; Lee, Ja-Kyeong

    2010-03-19

    Although RNA interference (RNAi)-mediated gene silencing provides a powerful strategy for modulating specific gene functions, difficulties associated with siRNA delivery have impeded the development of efficient therapeutic applications. In particular, the efficacy of siRNA delivery into neurons has been limited by extremely low transfection efficiencies. e-PAM-R is a biodegradable arginine ester of PAMAM dendrimer, which is readily degradable under physiological conditions (pH 7.4, 37 degrees C). In the present study, we investigated the efficiency of siRNA delivery by e-PAM-R in primary cortical cultures and in rat brain. e-PAM-R/siRNA complexes showed high transfection efficiencies and low cytotoxicities in primary cortical cultures. Localization of fluorescence-tagged siRNA revealed that siRNA was delivered not only into the nucleus and cytoplasm, but also along the processes of the neuron. e-PAM-R/siRNA complex-mediated target gene reduction was observed in over 40% of cells and it was persistent for over 48 h. The potential use of e-PAM-R was demonstrated by gene knockdown after transfecting High mobility group box-1 (HMGB1, a novel cytokine-like molecule) siRNA into H(2)O(2)- or NMDA-treated primary cortical cultures. In these cells, HMGB1 siRNA delivery successfully reduced both basal and H(2)O(2)- or NMDA-induced HMGB1 levels, and as a result of that, neuronal cell death was significantly suppressed in both cases. Furthermore, we showed that e-PAM-R successfully delivered HMGB1 siRNA into the rat brain, wherein HMGB1 expression was depleted in over 40% of neurons and astrocytes of the normal brain. Moreover, e-PAM-R-mediated HMGB1 siRNA delivery notably reduced infarct volume in the postischemic rat brain, which is generated by occluding the middle cerebral artery for 60 min. These results indicate that e-PAM-R, a novel biodegradable nonviral gene carrier, offers an efficient means of transfecting siRNA into primary neuronal cells and in the brain and of

  17. Intracellular Delivery of siRNA by Polycationic Superparamagnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Betzaida Castillo

    2012-01-01

    Full Text Available The siRNA transfection efficiency of nanoparticles (NPs, composed of a superparamagnetic iron oxide core modified with polycationic polymers (poly(hexamethylene biguanide or branched polyethyleneimine, were studied in CHO-K1 and HeLa cell lines. Both NPs demonstrated to be good siRNA transfection vehicles, but unmodified branched polyethyleneimine (25 kD was superior on both cell lines. However, application of an external magnetic field during transfection (magnetofection increased the efficiency of the superparamagnetic NPs. Furthermore, our results reveal that these NPs are less toxic towards CHO-K1 cell lines than the unmodified polycationic-branched polyethyleneimine (PEI. In general, the external magnetic field did not alter the cell’s viability nor it disrupted the cell membranes, except for the poly(hexamethylene biguanide-modified NP, where it was observed that in CHO-K1 cells application of the external magnetic field promoted membrane damage. This paper presents new polycationic superparamagnetic NPs as promising transfection vehicles for siRNA and demonstrates the advantages of magnetofection.

  18. Local administration of siRNA through Microneedle: Optimization, Bio-distribution, Tumor Suppression and Toxicity

    Science.gov (United States)

    Tang, Tao; Deng, Yan; Chen, Jiao; Zhao, Yi; Yue, Ruifeng; Choy, Kwong Wai; Wang, Chi Chiu; Du, Quan; Xu, Yan; Han, Linxiao; Chung, Tony Kwok Hung

    2016-07-01

    Although RNA interference may become a novel therapeutic approach for cancer treatment, target-site accumulation of siRNA to achieve therapeutic dosage will be a major problem. Microneedle represents a better way to deliver siRNAs and we have evaluated for the first time the capability of a silicon microneedle array for delivery of Gapdh siRNA to the skin in vivo and the results showed that the microneedle arrays could effectively deliver siRNA to relevant regions of the skin noninvasively. For the further study in this field, we evaluated the efficacy of the injectable microneedle device for local delivery of siRNA to the mouse xenograft. The results presented here indicate that local administration of siRNA through injectable microneedle could effectively deliver siRNA into the tumor region, and inhibit tumor progression without major adverse effects.

  19. Reverse osmosis water purification system

    Science.gov (United States)

    Ahlstrom, H. G.; Hames, P. S.; Menninger, F. J.

    1986-01-01

    A reverse osmosis water purification system, which uses a programmable controller (PC) as the control system, was designed and built to maintain the cleanliness and level of water for various systems of a 64-m antenna. The installation operates with other equipment of the antenna at the Goldstone Deep Space Communication Complex. The reverse osmosis system was designed to be fully automatic; with the PC, many complex sequential and timed logic networks were easily implemented and are modified. The PC monitors water levels, pressures, flows, control panel requests, and set points on analog meters; with this information various processes are initiated, monitored, modified, halted, or eliminated as required by the equipment being supplied pure water.

  20. A new helium gas recovery and purification system

    International Nuclear Information System (INIS)

    Yamamotot, T.; Suzuki, H.; Ishii, J.; Hamana, I.; Hayashi, S.; Mizutani, S.; Sanjo, S.

    1974-01-01

    A helium gas recovery and purification system, based on the principle of gas permeation through a membrane, is described. The system can be used for the purification of helium gas containing air as a contaminant. The apparatus, operating at ambient temperature does not need constant attention, the recovery ratio of helium gas is satisfactory and running costs are low. Gases other than helium can be processed with the apparatus. (U.K.)

  1. Improving the large scale purification of the HIV microbicide, griffithsin.

    Science.gov (United States)

    Fuqua, Joshua L; Wanga, Valentine; Palmer, Kenneth E

    2015-02-22

    Griffithsin is a broad spectrum antiviral lectin that inhibits viral entry and maturation processes through binding clusters of oligomannose glycans on viral envelope glycoproteins. An efficient, scaleable manufacturing process for griffithsin active pharmaceutical ingredient (API) is essential for particularly cost-sensitive products such as griffithsin -based topical microbicides for HIV-1 prevention in resource poor settings. Our previously published purification method used ceramic filtration followed by two chromatography steps, resulting in a protein recovery of 30%. Our objective was to develop a scalable purification method for griffithsin expressed in Nicotiana benthamiana plants that would increase yield, reduce production costs, and simplify manufacturing techniques. Considering the future need to transfer griffithsin manufacturing technology to resource poor areas, we chose to focus modifying the purification process, paying particular attention to introducing simple, low-cost, and scalable procedures such as use of temperature, pH, ion concentration, and filtration to enhance product recovery. We achieved >99% pure griffithsin API by generating the initial green juice extract in pH 4 buffer, heating the extract to 55°C, incubating overnight with a bentonite MgCl2 mixture, and final purification with Capto™ multimodal chromatography. Griffithsin extracted with this protocol maintains activity comparable to griffithsin purified by the previously published method and we are able to recover a substantially higher yield: 88 ± 5% of griffithsin from the initial extract. The method was scaled to produce gram quantities of griffithsin with high yields, low endotoxin levels, and low purification costs maintained. The methodology developed to purify griffithsin introduces and develops multiple tools for purification of recombinant proteins from plants at an industrial scale. These tools allow for robust cost-effective production and purification of

  2. Purification by ion exchange resins of the heavy water of the reactors EL 1 and EL 2. A - the purifying process. Equipment and results; Purification par resines echangeuses d'ions de l'eau lourde des reacteurs EL1 et EL2. A - conduite de la purification. Installations et resultats

    Energy Technology Data Exchange (ETDEWEB)

    Chenouard, J.; Roth, E. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    The heavy water was purified by tapping off part of the moderator over a mixed bed of anion and cation exchangers. The heavy water leaving the columns has a resistivity reaching several-meg-ohms, which allows the resistivity of the moderator to be maintained between 10{sup 5} and 10{sup 6} ohms/cm. Two methods of deuteration of the ion exchangers are described, as well as the heavy water recuperation from resins charged with radioactive products. The influence of the purity of the water on the radiolytic dissociation is investigated. An interpretation of the variations in pH and of the formation of hydrogen peroxide is given. In addition the report contains a general description of the EL1 and EL2 purification installations. (author) [French] L'epuration de l'eau lourde a ete effectuee en derivant une partie du moderateur sur un lit melange d'echangeurs d'anions et de cations. Les colonnes delivrent de l'eau lourde dont la resistivite atteint plusieurs megohms; ceci permet d'entretenir la resistivite du moderateur entre 10{sup 5} et 10{sup 6} ohms/cm. Deux procedes deuteriation des echangeurs d'ions sont decrits de meme que la recuperation de l'eau lourde partir des resines chargees de produits radioactifs. L'influence de la purete de l'eau sur sa dissociation radiolytique est etudiee. Une interpretation est donnee des variations de pH et de la formation d'eau oxygenee. Le rapport comprend en outre une description generale des installations d'epuration de EL1et EL2. (auteur)

  3. Purification by ion exchange resins of the heavy water of the reactors EL 1 and EL 2. A - the purifying process. Equipment and results; Purification par resines echangeuses d'ions de l'eau lourde des reacteurs EL1 et EL2. A - conduite de la purification. Installations et resultats

    Energy Technology Data Exchange (ETDEWEB)

    Chenouard, J; Roth, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    The heavy water was purified by tapping off part of the moderator over a mixed bed of anion and cation exchangers. The heavy water leaving the columns has a resistivity reaching several-meg-ohms, which allows the resistivity of the moderator to be maintained between 10{sup 5} and 10{sup 6} ohms/cm. Two methods of deuteration of the ion exchangers are described, as well as the heavy water recuperation from resins charged with radioactive products. The influence of the purity of the water on the radiolytic dissociation is investigated. An interpretation of the variations in pH and of the formation of hydrogen peroxide is given. In addition the report contains a general description of the EL1 and EL2 purification installations. (author) [French] L'epuration de l'eau lourde a ete effectuee en derivant une partie du moderateur sur un lit melange d'echangeurs d'anions et de cations. Les colonnes delivrent de l'eau lourde dont la resistivite atteint plusieurs megohms; ceci permet d'entretenir la resistivite du moderateur entre 10{sup 5} et 10{sup 6} ohms/cm. Deux procedes deuteriation des echangeurs d'ions sont decrits de meme que la recuperation de l'eau lourde partir des resines chargees de produits radioactifs. L'influence de la purete de l'eau sur sa dissociation radiolytique est etudiee. Une interpretation est donnee des variations de pH et de la formation d'eau oxygenee. Le rapport comprend en outre une description generale des installations d'epuration de EL1et EL2. (auteur)

  4. Nanomaterials and Water Purification: Opportunities and Challenges

    Science.gov (United States)

    Savage, Nora; Diallo, Mamadou S.

    2005-10-01

    Advances in nanoscale science and engineering suggest that many of the current problems involving water quality could be resolved or greatly ameliorated using nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes and nanoparticle enhanced filtration among other products and processes resulting from the development of nanotechnology. Innovations in the development of novel technologies to desalinate water are among the most exciting and promising. Additionally, nanotechnology-derived products that reduce the concentrations of toxic compounds to sub-ppb levels can assist in the attainment of water quality standards and health advisories. This article gives an overview of the use of nanomaterials in water purification. We highlight recent advances on the development of novel nanoscale materials and processes for treatment of surface water, groundwater and industrial wastewater contaminated by toxic metal ions, radionuclides, organic and inorganic solutes, bacteria and viruses. In addition, we discuss some challenges associated with the development of cost effective and environmentally acceptable functional nanomaterials for water purification.

  5. Nanomaterials and Water Purification: Opportunities and Challenges

    International Nuclear Information System (INIS)

    Savage, Nora; Diallo, Mamadou S.

    2005-01-01

    Advances in nanoscale science and engineering suggest that many of the current problems involving water quality could be resolved or greatly ameliorated using nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes and nanoparticle enhanced filtration among other products and processes resulting from the development of nanotechnology. Innovations in the development of novel technologies to desalinate water are among the most exciting and promising. Additionally, nanotechnology-derived products that reduce the concentrations of toxic compounds to sub-ppb levels can assist in the attainment of water quality standards and health advisories. This article gives an overview of the use of nanomaterials in water purification. We highlight recent advances on the development of novel nanoscale materials and processes for treatment of surface water, groundwater and industrial wastewater contaminated by toxic metal ions, radionuclides, organic and inorganic solutes, bacteria and viruses. In addition, we discuss some challenges associated with the development of cost effective and environmentally acceptable functional nanomaterials for water purification

  6. Air/Water Purification

    Science.gov (United States)

    1992-01-01

    After 18 years of research into air/water pollution at Stennis Space Center, Dr. B. C. Wolverton formed his own company, Wolverton Environmental Services, Inc., to provide technology and consultation in air and water treatment. Common houseplants are used to absorb potentially harmful materials from bathrooms and kitchens. The plants are fertilized, air is purified, and wastewater is converted to clean water. More than 100 U.S. communities have adopted Wolverton's earlier water hyacinth and artificial marsh applications. Catfish farmers are currently evaluating the artificial marsh technology as a purification system.

  7. Water Purification Product

    Science.gov (United States)

    2004-01-01

    Ecomaster, an affiliate of BioServe Space Technologies, this PentaPure technology has been used to purify water for our nation's Space Shuttle missions since 1981. WTC-Ecomaster of Mirneapolis, Minnesota manufactures water purification systems under the brand name PentaPure (TM). BioServe researcher Dr. George Marchin, of Kansas State University, first demonstrated the superiority of this technology and licensed it to WTC. Marchin continues to perform microgravity research in the development of new technologies for the benefit of life on Earth.

  8. Gas purification project

    International Nuclear Information System (INIS)

    Broothaerts, J.; Claes, J.; Collard, G.; Goossens, W.; Harnie, R.; Heylen, P.; Vaesen, J.; Beukelaer, R. de; Dubois, G.; Glibert, R.; Mestrez, J.; Zahlen, A.

    1975-06-01

    Conceptual and experimental studies on LMFBR reprocessing and reactor off-gas purification systems are summarized. Iodine sorption on zeolites, low-temperature adsorption of noble gases on charcoal and catalytic oxidation of hydrogen, simulating tritium, are being studied in laboratory set-ups. A pilot loop with 25 m 3 h -1 throughput has been constructed. Results are quoted from the first phase of the iodine removal programme by scrubbing systems. Further extension of the test loop, comprising off-gases conditioning to removal of krypton in a cryodistillation unit, has been prepared. Delay-bed studies on 133 Xe extraction from LWR off-gases are reported. (author)

  9. Study of the conditions of activation and stabilization of Shigella sonnei 47 DNA methylases in the process of fractionation, purification, and during storage

    International Nuclear Information System (INIS)

    Suchkov, S.V.; Lopatina, N.G.; Arutyunyan, E.E.; Nikol'skaya, I.I.; Debov, S.S.

    1987-01-01

    A comparative investigation was made of the factors of activation and conditions of stabilization of partially purified and individual fractions of DNA methylases of the strain Shigella sonnei 47. The influence of the temperature system, glycerin, albumin, protease inhibitors, divalent metal ions, as well as the conditions of storage at the value of the isoelectric point of the protein on the activity of the enzymes of methylation was studied. It was shown that the effects of activating factors and levels of stabilization differ appreciably, depending on the degree of purification and the composition of the enzyme preparations. It was established that glycerin is ineffective as a stabilizing agent. It was shown that of all the divalent cations studied the only activator universal for the methylases of Shigella sonnei 47 is Ca 2+ ions. A pronounced stabilizing effect of albumin on the activity of these DNA methylases was demonstrated. With the exception of one enzymatic fraction, the protease inhibitors have virtually no effect on the level of methylating activity of the preparations. The phenomenon of spontaneous fluctuations of the methylating activity of Shigella sonnei 47 enzyme preparations during storage is described

  10. A food-grade process for isolation and partial purification of bacteriocins of lactic acid bacteria that uses diatomite calcium silicate.

    Science.gov (United States)

    Coventry, M J; Gordon, J B; Alexander, M; Hickey, M W; Wan, J

    1996-01-01

    Bacteriocins, including nisin, pediocin PO2, brevicin 286, and piscicolin 126, were extracted from fermentation media by adsorption onto Micro-Cel (a food-grade diatomite calcium silicate anticaking agent) and subsequent desorption. The optimal conditions for desorption of piscicolin 126 were determined and applied to other bacteriocins, and the relative purities of the desorbed preparations were compared. Piscicolin was not successfully desorbed from Micro-Cel at pH 1.0 to 12.0, with organic solvents, or by increase of ionic strength up to 1 M NaCl. However, 25 and 75% of the bacteriocin activity was desorbed by using 1% sodium deoxycholate and 1% sodium dodecyl sulfate (SDS), respectively. Higher levels (up to 100%) of desorption were achieved by repeated elution or by an increase in surfactant concentration. Desorption of piscicolin with 1/10 volume of SDS solution resulted in a preparation with 10 times concentration in activity, equivalent to that of ammonium sulfate preparations (409,600 to 819,200 activity units/ml). Determination of organic nitrogen (N) content revealed that the desorbed piscicolin preparations were substantially free of proteinaceous substances (approximately 92 to 99%) compared with original culture supernatants and ammonium sulfate preparations. Nisin, pediocin, and brevicin were also desorbed with 1% SDS with a similar level of purification. PMID:8633875

  11. Microbiological and technical aspects of anaerobic waste water purification

    International Nuclear Information System (INIS)

    Aivasidis, A.

    1994-01-01

    Anaerobic waste water purification is likely to be another example of how innovations can result from the joint use of biological and technical concepts. No matter how far the optimization of oxygen input with aerobic waste water purification advances it will still be the less a real competitor for anaerobic techniques the more polluted the waste water is. The principle of carrier fixation to avoid their washing out, too, has often been observed in nature with sessile microorganisms. With highly polluted water, anaerobic purification does not only work at no expenditure of energy but it can also make excess energy available for use in other processes. Another important argument for anaerobic methods of waste water purification is probably the clearly reduced production of excess sludge. (orig.) [de

  12. Rotating Reverse-Osmosis for Water Purification

    Science.gov (United States)

    Lueptow, RIchard M.

    2004-01-01

    A new design for a water-filtering device combines rotating filtration with reverse osmosis to create a rotating reverse- osmosis system. Rotating filtration has been used for separating plasma from whole blood, while reverse osmosis has been used in purification of water and in some chemical processes. Reverse- osmosis membranes are vulnerable to concentration polarization a type of fouling in which the chemicals meant not to pass through the reverse-osmosis membranes accumulate very near the surfaces of the membranes. The combination of rotating filtration and reverse osmosis is intended to prevent concentration polarization and thereby increase the desired flux of filtered water while decreasing the likelihood of passage of undesired chemical species through the filter. Devices based on this concept could be useful in a variety of commercial applications, including purification and desalination of drinking water, purification of pharmaceutical process water, treatment of household and industrial wastewater, and treatment of industrial process water. A rotating filter consists of a cylindrical porous microfilter rotating within a stationary concentric cylindrical outer shell (see figure). The aqueous suspension enters one end of the annulus between the inner and outer cylinders. Filtrate passes through the rotating cylindrical microfilter and is removed via a hollow shaft. The concentrated suspension is removed at the end of the annulus opposite the end where the suspension entered.

  13. siRNA Transfection and EMSA Analyses on Freshly Isolated Human Villous Cytotrophoblasts.

    Science.gov (United States)

    Lokossou, Adjimon Gatien; Toufaily, Chirine; Vargas, Amandine; Barbeau, Benoit

    2016-09-20

    Human primary villous cytotrophoblasts are a very useful source of primary cells to study placental functions and regulatory mechanisms, and to comprehend diseases related to pregnancy. In this protocol, human primary villous cytotrophoblasts freshly isolated from placentas through a standard DNase/trypsin protocol are microporated with small interfering RNA (siRNA). This approach provided greater efficiency for siRNA transfection when compared to a lipofection-based method. Transfected cells can subsequently be analyzed by standard Western blot within a time frame of 3-4 days post-transfection. In addition, using cultured primary villous cytotrophoblasts, Electrophoretic Mobility Shift Assay (EMSA) analysis was optimized and performed on extracts from days 1 to 4. The use of these cultured primary cells and the protocol described allow for an evaluation of the implication of specific genes and transcription factors in the process of villous cytotrophoblast differentiation into a syncytiotrophoblast-like cell layer. However, the limited time span allowable in culture precludes the use of methods requiring more time, such as generation of a stable cell population. Therefore testing of this cell population requires highly optimized gene transfer protocols.

  14. Pulmonary Delivery of siRNA via Polymeric Vectors as Therapies of Asthma.

    Science.gov (United States)

    Xie, Yuran; Merkel, Olivia M

    2015-10-01

    Asthma is a chronic inflammatory disease. Despite the fact that current therapies, such as the combination of inhaled corticosteroids and β2-agonists, can control the symptoms of asthma in most patients, there is still an urgent need for an alternative anti-inflammatory therapy for patients who suffer from severe asthma but lack acceptable response to conventional therapies. Many molecular factors are involved in the inflammatory process in asthma, and thus blocking the function of these factors could efficiently alleviate airway inflammation. RNA interference (RNAi) is often thought to be the answer in the search for more efficient and biocompatible treatments. However, difficulties of efficient delivery of small interference RNA (siRNA), the key factor in RNAi, to target cells and tissues have limited its clinical application. In this review, we summarize cytokines and chemokines, transcription factors, tyrosine kinases, and costimulatory factors that have been reported as targets of siRNA-mediated treatment in experimental asthma. Additionally, we conclude several targeted delivery systems of siRNA to specific cells such as T cells, macrophages, and dendritic cells, which could potentially be applied in asthma therapy. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Evaluation of carrier-mediated siRNA delivery

    DEFF Research Database (Denmark)

    Colombo, Stefano; Nielsen, Hanne Mørck; Foged, Camilla

    2013-01-01

    RNA delivery. An in vitro cell culture model system expressing enhanced green fluorescent protein (EGFP) was used to develop the assay, which was based on the intracellular quantification of a full-length double-stranded Dicer substrate siRNA by stem-loop RT qPCR. The result is a well-documented protocol......RNA delivered by use of carriers remains an analytical challenge. The purpose of the present study was to optimize and validate an analytical protocol based on stem-loop reverse transcription quantitative polymerase chain reaction (RT qPCR) to quantitatively monitor the carrier-mediated intracellular si...

  16. Multifunctional selenium nanoparticles as carriers of HSP70 siRNA to induce apoptosis of HepG2 cells

    Directory of Open Access Journals (Sweden)

    Li Y

    2016-07-01

    Full Text Available Yinghua Li,1 Zhengfang Lin,1 Mingqi Zhao,1 Tiantian Xu,1 Changbing Wang,1 Huimin Xia,1,* Hanzhong Wang,2,* Bing Zhu1,* 1Guangzhou Women and Children’s Medical Center, Guangzhou, Guangdong, 2State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, People’s Republic of China *These authors contributed equally to this work Abstract: Small interfering RNA (siRNA as a new therapeutic modality holds promise for cancer treatment, but it is unable to cross cell membrane. To overcome this limitation, nanotechnology has been proposed for mediation of siRNA transfection. Selenium (Se is a vital dietary trace element for mammalian life and plays an essential role in the growth and functioning of humans. As a novel Se species, Se nanoparticles have attracted more and more attention for their higher anticancer efficacy. In the present study, siRNAs with polyethylenimine (PEI-modified Se nanoparticles (Se@PEI@siRNA have been demonstrated to enhance the apoptosis of HepG2 cells. Heat shock protein (HSP-70 is overexpressed in many types of human cancer and plays a significant role in several biological processes including the regulation of apoptosis. The objective of this study was to silence inducible HSP70 and promote the apoptosis of Se-induced HepG2 cells. Se@PEI@siRNA were successfully prepared and characterized by various microscopic methods. Se@PEI@siRNA showed satisfactory size distribution, high stability, and selectivity between cancer and normal cells. The cytotoxicity of Se@PEI@siRNA was lower for normal cells than tumor cells, indicating that these compounds may have fewer side effects. The gene-silencing efficiency of Se@PEI@siRNA was significantly much higher than Lipofectamine 2000@siRNA and resulted in a significantly reduced HSP70 mRNA and protein expression in cancer cells. When the expression of HSP70 was diminished, the function of cell protection was also removed and cancer cells became more

  17. Effect of charcoal on water purification

    OpenAIRE

    Suzuki, Hirotaka; Kawahigashi, Tatsuo

    2014-01-01

    [Abstract] A natural basin system purifies water through self-purification, but the water pollution load of a river might exceed its self-purification capacity. Charcoal, which is used for other uses aside from heating, such as air purification, was evaluated experimentally for water quality purification. The experiment described herein is based on simple water quality measurements. Some experimentally obtained results are discussed.

  18. Hydroxychloroquine-conjugated gold nanoparticles for improved siRNA activity.

    Science.gov (United States)

    Perche, F; Yi, Y; Hespel, L; Mi, P; Dirisala, A; Cabral, H; Miyata, K; Kataoka, K

    2016-06-01

    Current technology of siRNA delivery relies on pharmaceutical dosage forms to route maximal doses of siRNA to the tumor. However, this rationale does not address intracellular bottlenecks governing silencing activity. Here, we tested the impact of hydroxychloroquine conjugation on the intracellular fate and silencing activity of siRNA conjugated PEGylated gold nanoparticles. Addition of hydroxychloroquine improved endosomal escape and increased siRNA guide strand distribution to the RNA induced silencing complex (RISC), both crucial obstacles to the potency of siRNA. This modification significantly improved gene downregulation in cellulo. Altogether, our data suggest the benefit of this modification for the design of improved siRNA delivery systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Phase equilibria at the Zirconium metal purification

    International Nuclear Information System (INIS)

    Dwiretnani-Sudjoko; Busron-Masduki; Sunardjo; Budi-Sulistyo

    1996-01-01

    It was investigated the research in the purification of zirconium metal, which was results from the reduction process, by adding heat in the vacuum environment. The process was done in batch in the stainless steel reactor, equiped with vacuum pump and electric heater. The investigated variable were process temperature and pressure. From this research it was obtained that equilibrium constant for MgCl 2 and Mg were expressed in the equation K M g C l 2 = 0.9011 P 1 .3779 1.06552 T and K M g = 6.0115P + 1.35256T - 6.93912

  20. Affinity chromatography: A versatile technique for antibody purification.

    Science.gov (United States)

    Arora, Sushrut; Saxena, Vikas; Ayyar, B Vijayalakshmi

    2017-03-01

    Antibodies continue to be extremely utilized entities in myriad applications including basic research, imaging, targeted delivery, chromatography, diagnostics, and therapeutics. At production stage, antibodies are generally present in complex matrices and most of their intended applications necessitate purification. Antibody purification has always been a major bottleneck in downstream processing of antibodies, due to the need of high quality products and associated high costs. Over the years, extensive research has focused on finding better purification methodologies to overcome this holdup. Among a plethora of different techniques, affinity chromatography is one of the most selective, rapid and easy method for antibody purification. This review aims to provide a detailed overview on affinity chromatography and the components involved in purification. An array of support matrices along with various classes of affinity ligands detailing their underlying working principles, together with the advantages and limitations of each system in purifying different types of antibodies, accompanying recent developments and important practical methodological considerations to optimize purification procedure are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. MysiRNA-designer: a workflow for efficient siRNA design.

    Directory of Open Access Journals (Sweden)

    Mohamed Mysara

    Full Text Available The design of small interfering RNA (siRNA is a multi factorial problem that has gained the attention of many researchers in the area of therapeutic and functional genomics. MysiRNA score was previously introduced that improves the correlation of siRNA activity prediction considering state of the art algorithms. In this paper, a new program, MysiRNA-Designer, is described which integrates several factors in an automated work-flow considering mRNA transcripts variations, siRNA and mRNA target accessibility, and both near-perfect and partial off-target matches. It also features the MysiRNA score, a highly ranked correlated siRNA efficacy prediction score for ranking the designed siRNAs, in addition to top scoring models Biopredsi, DISR, Thermocomposition21 and i-Score, and integrates them in a unique siRNA score-filtration technique. This multi-score filtration layer filters siRNA that passes the 90% thresholds calculated from experimental dataset features. MysiRNA-Designer takes an accession, finds conserved regions among its transcript space, finds accessible regions within the mRNA, designs all possible siRNAs for these regions, filters them based on multi-scores thresholds, and then performs SNP and off-target filtration. These strict selection criteria were tested against human genes in which at least one active siRNA was designed from 95.7% of total genes. In addition, when tested against an experimental dataset, MysiRNA-Designer was found capable of rejecting 98% of the false positive siRNAs, showing superiority over three state of the art siRNA design programs. MysiRNA is a freely accessible (Microsoft Windows based desktop application that can be used to design siRNA with a high accuracy and specificity. We believe that MysiRNA-Designer has the potential to play an important role in this area.

  2. DBR1 siRNA inhibition of HIV-1 replication

    Directory of Open Access Journals (Sweden)

    Naidu Yathi

    2005-10-01

    Full Text Available Abstract Background HIV-1 and all retroviruses are related to retroelements of simpler organisms such as the yeast Ty elements. Recent work has suggested that the yeast retroelement Ty1 replicates via an unexpected RNA lariat intermediate in cDNA synthesis. The putative genomic RNA lariat intermediate is formed by a 2'-5' phosphodiester bond, like that found in pre-mRNA intron lariats and it facilitates the minus-strand template switch during cDNA synthesis. We hypothesized that HIV-1 might also form a genomic RNA lariat and therefore that siRNA-mediated inhibition of expression of the human RNA lariat de-branching enzyme (DBR1 expression would specifically inhibit HIV-1 replication. Results We designed three short interfering RNA (siRNA molecules targeting DBR1, which were capable of reducing DBR1 mRNA expression by 80% and did not significantly affect cell viability. We assessed HIV-1 replication in the presence of DBR1 siRNA and found that DBR1 knockdown led to decreases in viral cDNA and protein production. These effects could be reversed by cotransfection of a DBR1 cDNA indicating that the inhibition of HIV-1 replication was a specific effect of DBR1 underexpression. Conclusion These data suggest that DBR1 function may be needed to debranch a putative HIV-1 genomic RNA lariat prior to completion of reverse transcription.

  3. SiRNA Crosslinked Nanoparticles for the Treatment of Inflammation-induced Liver Injury.

    Science.gov (United States)

    Tang, Yaqin; Zeng, Ziying; He, Xiao; Wang, Tingting; Ning, Xinghai; Feng, Xuli

    2017-02-01

    RNA interference mediated by small interfering RNA (siRNA) provides a powerful tool for gene regulation, and has a broad potential as a promising therapeutic strategy. However, therapeutics based on siRNA have had limited clinical success due to their undesirable pharmacokinetic properties. This study presents pH-sensitive nanoparticles-based siRNA delivery systems (PNSDS), which are positive-charge-free nanocarriers, composed of siRNA chemically crosslinked with multi-armed poly(ethylene glycol) carriers via acid-labile acetal linkers. The unique siRNA crosslinked structure of PNSDS allows it to have minimal cytotoxicity, high siRNA loading efficiency, and a stimulus-responsive property that enables the selective intracellular release of siRNA in response to pH conditions. This study demonstrates that PNSDS can deliver tumor necrosis factor alpha (TNF-α) siRNA into macrophages and induce the efficient down regulation of the targeted gene in complete cell culture media. Moreover, PNSDS with mannose targeting moieties can selectively accumulate in mice liver, induce specific inhibition of macrophage TNF-α expression in vivo, and consequently protect mice from inflammation-induced liver damages. Therefore, this novel siRNA delivering platform would greatly improve the therapeutic potential of RNAi based therapies.

  4. Item Purification Does Not Always Improve DIF Detection: A Counterexample with Angoff's Delta Plot

    Science.gov (United States)

    Magis, David; Facon, Bruno

    2013-01-01

    Item purification is an iterative process that is often advocated as improving the identification of items affected by differential item functioning (DIF). With test-score-based DIF detection methods, item purification iteratively removes the items currently flagged as DIF from the test scores to get purified sets of items, unaffected by DIF. The…

  5. Reducing the Cytotoxicity of Lipid Nanoparticles Associated with a Fusogenic Cationic Lipid in a Natural Killer Cell Line by Introducing a Polycation-Based siRNA Core.

    Science.gov (United States)

    Nakamura, Takashi; Yamada, Koharu; Fujiwara, Yuki; Sato, Yusuke; Harashima, Hideyoshi

    2018-06-04

    Introducing siRNA into human immune cells by an artificial delivery system continues to be a challenging issue. We previously developed a multifunctional envelope-type nanodevice (MEND) containing the YSK12-C4, a fusogenic cationic lipid, (YSK12-MEND) and succeeded in the efficient delivery of siRNA into human immune cell lines. Significant cytotoxicity, however, was observed at siRNA doses needed for gene silencing in NK-92 cells. NK-92 cells, a unique natural killer (NK) cell line, would be applicable for use in clinical NK therapy. Thus, reducing the cytotoxicity of the YSK12-MEND in NK-92 cells would strengthen the efficacy of NK-92 cell-based therapy. The amount of the YSK12-C4 in the MEND needed to be reduced to reduce the cytotoxicity, because the cytotoxicity was directly associated with the YSK12-C4. In the present study, we decreased the total amount of lipid, including the YSK12-C4, by introducing a core formed by electrostatic interactions of siRNA with a polycation (protamine) (siRNA core), which led to a decrease in cytotoxicity in NK-92 cells. We prepared a YSK12-MEND containing an siRNA core (YSK12-MEND/core) at charge ratios (CR: YSK12-C4/siRNA) of 10, 5, 3, and 2.5 and compared the YSK12-MEND/core with that for a YSK12-MEND (CR16.9). Cell viability was increased by more than 2 times at a CR5 or less. On the other hand, the YSK12-MEND/core (CR5) maintained the same gene silencing efficiency (60%) as the YSK12-MEND. Interestingly, the cellular uptake efficiency and hemolytic activity of the YSK12-MEND/core (CR5) was reduced compared to that for the YSK12-MEND. In calculating the silencing activity per cellular uptake efficiency and hemolytic activity, the value for the YSK12-MEND/core (CR5) was more than 2 times as high as that of the YSK12-MEND. The fact indicates that after endosomal escape, the process can be enhanced by using a YSK12-MEND/core (CR5). Thus, introducing an siRNA core into lipid nanoparticles can be a potent strategy for decreasing

  6. Treating respiratory viral diseases with chemically modified, second generation intranasal siRNAs.

    Science.gov (United States)

    Barik, Sailen

    2009-01-01

    Chemically synthesized short interfering RNA (siRNA) of pre-determined sequence has ushered a new era in the application of RNA interference (RNAi) against viral genes. We have paid particular attention to respiratory viruses that wreak heavy morbidity and mortality worldwide. The clinically significant ones include respiratory syncytial virus (RSV), parainfluenza virus (PIV) and influenza virus. As the infection by these viruses is clinically restricted to the respiratory tissues, mainly the lungs, the logical route for the application of the siRNA was also the same, i.e., via the nasal route. Following the initial success of intranasal siRNA against RSV, second-generation siRNAs were made against the viral polymerase large subunit (L) that were chemically modified and screened for improved stability, activity and pharmacokinetics. 2'-O-methyl (2'-O-Me) and 2'-deoxy-2'-fluoro (2'-F) substitutions in the ribose ring were incorporated in different positions of the sense and antisense strands and the resultant siRNAs were tested with various transfection reagents intranasally against RSV. Based on these results, we propose the following consensus for designing intranasal antiviral siRNAs: (i) modified 19-27 nt long double-stranded siRNAs are functional in the lung, (ii) excessive 2'-OMe and 2'-F modifications in either or both strands of these siRNAs reduce efficacy, and (iii) limited modifications in the sense strand are beneficial, although their precise efficacy may be position-dependent.

  7. Targeted delivery of anti-coxsackievirus siRNAs using ligand-conjugated packaging RNAs.

    Science.gov (United States)

    Zhang, Huifang M; Su, Yue; Guo, Songchuan; Yuan, Ji; Lim, Travis; Liu, Jing; Guo, Peixuan; Yang, Decheng

    2009-09-01

    Coxsackievirus B3 (CVB3) is a common pathogen of myocarditis. We previously synthesized a siRNA targeting the CVB3 protease 2A (siRNA/2A) gene and achieved reduction of CVB3 replication by 92% in vitro. However, like other drugs under development, CVB3 siRNA faces a major challenge of targeted delivery. In this study, we investigated a novel approach to deliver CVB3 siRNAs to a specific cell population (e.g. HeLa cells containing folate receptor) using receptor ligand (folate)-linked packaging RNA (pRNA) from bacterial phage phi29. pRNA monomers can spontaneously form dimers and multimers under optimal conditions by base-pairing between their stem loops. By covalently linking a fluorescence-tag to folate, we delivered the conjugate specifically to HeLa cells without the need of transfection. We further demonstrated that pRNA covalently conjugated to siRNA/2A achieved an equivalent antiviral effect to that of the siRNA/2A alone. Finally, the drug targeted delivery was further evaluated by using pRNA monomers or dimers, which carried both the siRNA/2A and folate ligand and demonstrated that both of them strongly inhibited CVB3 replication. These data indicate that pRNA as a siRNA carrier can specifically deliver the drug to target cells via its ligand and specific receptor interaction and inhibit virus replication effectively.

  8. siRNAmod: A database of experimentally validated chemically modified siRNAs.

    Science.gov (United States)

    Dar, Showkat Ahmad; Thakur, Anamika; Qureshi, Abid; Kumar, Manoj

    2016-01-28

    Small interfering RNA (siRNA) technology has vast potential for functional genomics and development of therapeutics. However, it faces many obstacles predominantly instability of siRNAs due to nuclease digestion and subsequently biologically short half-life. Chemical modifications in siRNAs provide means to overcome these shortcomings and improve their stability and potency. Despite enormous utility bioinformatics resource of these chemically modified siRNAs (cm-siRNAs) is lacking. Therefore, we have developed siRNAmod, a specialized databank for chemically modified siRNAs. Currently, our repository contains a total of 4894 chemically modified-siRNA sequences, comprising 128 unique chemical modifications on different positions with various permutations and combinations. It incorporates important information on siRNA sequence, chemical modification, their number and respective position, structure, simplified molecular input line entry system canonical (SMILES), efficacy of modified siRNA, target gene, cell line, experimental methods, reference etc. It is developed and hosted using Linux Apache MySQL PHP (LAMP) software bundle. Standard user-friendly browse, search facility and analysis tools are also integrated. It would assist in understanding the effect of chemical modifications and further development of stable and efficacious siRNAs for research as well as therapeutics. siRNAmod is freely available at: http://crdd.osdd.net/servers/sirnamod.

  9. A novel program to design siRNAs simultaneously effective to highly variable virus genomes.

    Science.gov (United States)

    Lee, Hui Sun; Ahn, Jeonghyun; Jun, Eun Jung; Yang, Sanghwa; Joo, Chul Hyun; Kim, Yoo Kyum; Lee, Heuiran

    2009-07-10

    A major concern of antiviral therapy using small interfering RNAs (siRNAs) targeting RNA viral genome is high sequence diversity and mutation rate due to genetic instability. To overcome this problem, it is indispensable to design siRNAs targeting highly conserved regions. We thus designed CAPSID (Convenient Application Program for siRNA Design), a novel bioinformatics program to identify siRNAs targeting highly conserved regions within RNA viral genomes. From a set of input RNAs of diverse sequences, CAPSID rapidly searches conserved patterns and suggests highly potent siRNA candidates in a hierarchical manner. To validate the usefulness of this novel program, we investigated the antiviral potency of universal siRNA for various Human enterovirus B (HEB) serotypes. Assessment of antiviral efficacy using Hela cells, clearly demonstrates that HEB-specific siRNAs exhibit protective effects against all HEBs examined. These findings strongly indicate that CAPSID can be applied to select universal antiviral siRNAs against highly divergent viral genomes.

  10. Polo-like kinase 1 siRNA-607 induces mitotic arrest and apoptosis in ...

    African Journals Online (AJOL)

    Polo-like kinase (Plk) 1 is overexpressed in many human malignancies including nasopharyngeal carcinoma, indicating its potential as a therapeutic target. Recently, using a simple cellular morphologybased strategy, we have identified several novel effective siRNAs against Plk1 including Plk1 siRNA- 607. In this study, we ...

  11. Functional characterization of endogenous siRNA target genes in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Heikkinen Liisa

    2008-06-01

    Full Text Available Abstract Background Small interfering RNA (siRNA molecules mediate sequence specific silencing in RNA interference (RNAi, a gene regulatory phenomenon observed in almost all organisms. Large scale sequencing of small RNA libraries obtained from C. elegans has revealed that a broad spectrum of siRNAs is endogenously transcribed from genomic sequences. The biological role and molecular diversity of C. elegans endogenous siRNA (endo-siRNA molecules, nonetheless, remain poorly understood. In order to gain insight into their biological function, we annotated two large libraries of endo-siRNA sequences, identified their cognate targets, and performed gene ontology analysis to identify enriched functional categories. Results Systematic trends in categorization of target genes according to the specific length of siRNA sequences were observed: 18- to 22-mer siRNAs were associated with genes required for embryonic development; 23-mers were associated uniquely with post-embryonic development; 24–26-mers were associated with phosphorus metabolism or protein modification. Moreover, we observe that some argonaute related genes associate with siRNAs with multiple reads. Sequence frequency graphs suggest that different lengths of siRNAs share similarities in overall sequence structure: the 5' end begins with G, while the body predominates with U and C. Conclusion These results suggest that the lengths of endogenous siRNA molecules are consequential to their biological functions since the gene ontology categories for their cognate mRNA targets vary depending upon their lengths.

  12. Intravenous siRNA of brain cancer with receptor targeting and avidin-biotin technology.

    Science.gov (United States)

    Xia, Chun-Fang; Zhang, Yufeng; Zhang, Yun; Boado, Ruben J; Pardridge, William M

    2007-12-01

    The effective delivery of short interfering RNA (siRNA) to brain following intravenous administration requires the development of a delivery system for transport of the siRNA across the brain capillary endothelial wall, which forms the blood-brain barrier in vivo. siRNA was delivered to brain in vivo with the combined use of a receptor-specific monoclonal antibody delivery system, and avidin-biotin technology. The siRNA was mono-biotinylated on either terminus of the sense strand, in parallel with the production of a conjugate of the targeting MAb and streptavidin. Rat glial cells (C6 or RG-2) were permanently transfected with the luciferase gene, and implanted in the brain of adult rats. Following the formation of intra-cranial tumors, the rats were treated with a single intravenous injection of 270 microg/kg of biotinylated siRNA attached to a transferrin receptor antibody via a biotin-streptavidin linker. The intravenous administration of the siRNA caused a 69-81% decrease in luciferase gene expression in the intracranial brain cancer in vivo. Brain delivery of siRNA following intravenous administration is possible with siRNAs that are targeted to brain with the combined use of receptor specific antibody delivery systems and avidin-biotin technology.

  13. siRNAs Targeting Viral Protein 5: The Major Capsid Protein of ...

    African Journals Online (AJOL)

    Purpose: To investigate whether siRNA targeting viral protein 5 (VP5) can become a new treatment for herpes simplex virus type 1 (HSV-1). Methods: Flow cytometry was performed to determine the ratio of siRNA and lipo2000 to reach the highest transfection efficiency. Western blot and q-PCR were performed to determine ...

  14. Bioreducible poly(amido amine)s for siRNA delivery

    NARCIS (Netherlands)

    van der Aa, L.J.

    2011-01-01

    Successes in RNA interference based therapies are still limited due to the lack of efficient delivery of the mediator, small interfering RNA (siRNA), to the targeted site. The key to success can be the delivery of the siRNA molecules by polymer-based carrier systems, since they can be chemically

  15. Cu-TDPAT, an rht -type dual-functional metal-organic framework offering significant potential for use in H 2 and natural gas purification processes operating at high pressures

    KAUST Repository

    Wu, Haohan; Yao, Kexin; Zhu, Yihan; Li, Baiyan; Shi, Zhan; Krishna, Rajamani A A; Li, Jing

    2012-01-01

    The separations of CO 2/CO/CH 4/H 2, CO 2/H 2, CH 4/H 2, and CO 2/CH 4 mixtures at pressures ranging to 7 MPa are important in a variety of contexts, including H 2 production, natural gas purification, and fuel-gas processing. The primary objective of this study is to demonstrate the selective adsorption potential of an rht-type metal-organic framework [Cu 3(TDPAT)(H 2O) 3]·10H 2O·5DMA (Cu-TDPAT), possessing a high density of both open metal sites and Lewis basic sites. Experimental high pressure pure component isotherm data for CO 2, CO, CH 4, and H 2 are combined with the Ideal Adsorbed Solution Theory (IAST) for estimation of mixture adsorption equilibrium. The separation performance of Cu-TDPAT is compared with four other microporous materials, specifically chosen in order to span a wide range of physicochemical characteristics: MgMOF-74, MIL-101, LTA-5A, and NaX. For all mixtures investigated, the capacity of Cu-TDPAT to produce the desired product, H 2 or CH 4, satisfying stringent purity requirements, in a fixed bed operating at pressures exceeding about 4 MPa, is either comparable to, or exceeds, that of other materials. © 2012 American Chemical Society.

  16. Cu-TDPAT, an rht -type dual-functional metal-organic framework offering significant potential for use in H 2 and natural gas purification processes operating at high pressures

    KAUST Repository

    Wu, Haohan

    2012-08-09

    The separations of CO 2/CO/CH 4/H 2, CO 2/H 2, CH 4/H 2, and CO 2/CH 4 mixtures at pressures ranging to 7 MPa are important in a variety of contexts, including H 2 production, natural gas purification, and fuel-gas processing. The primary objective of this study is to demonstrate the selective adsorption potential of an rht-type metal-organic framework [Cu 3(TDPAT)(H 2O) 3]·10H 2O·5DMA (Cu-TDPAT), possessing a high density of both open metal sites and Lewis basic sites. Experimental high pressure pure component isotherm data for CO 2, CO, CH 4, and H 2 are combined with the Ideal Adsorbed Solution Theory (IAST) for estimation of mixture adsorption equilibrium. The separation performance of Cu-TDPAT is compared with four other microporous materials, specifically chosen in order to span a wide range of physicochemical characteristics: MgMOF-74, MIL-101, LTA-5A, and NaX. For all mixtures investigated, the capacity of Cu-TDPAT to produce the desired product, H 2 or CH 4, satisfying stringent purity requirements, in a fixed bed operating at pressures exceeding about 4 MPa, is either comparable to, or exceeds, that of other materials. © 2012 American Chemical Society.

  17. Efficient siRNA delivery system using carboxilated single-wall carbon nanotubes in cancer treatment.

    Science.gov (United States)

    Neagoe, Ioana Berindan; Braicu, Cornelia; Matea, Cristian; Bele, Constantin; Florin, Graur; Gabriel, Katona; Veronica, Chedea; Irimie, Alexandru

    2012-08-01

    Several functionalized carbon nanotubes have been designed and tested for the purpose of nucleic acid delivery. In this study, the capacity of SWNTC-COOH for siRNA deliverey were investigated delivery in parallel with an efficient commercial system. Hep2G cells were reverse-transfected with 50 nM siRNA (p53 siRNA, TNF-alphasiRNA, VEGFsiRNA) using the siPORT NeoFX (Ambion) transfection agent in paralel with SWNTC-COOH, functionalised with siRNA. The highest level of gene inhibition was observed in the cases treated with p53 siRNA gene; in the case of transfection with siPort, the NeoFX value was 33.8%, while in the case of SWNTC-COOH as delivery system for p53 siRNA was 37.5%. The gene silencing capacity for VEGF was 53.7%, respectively for TNF-alpha 56.7% for siPORT NeoFX delivery systems versus 47.7% (VEGF) and 46.5% (TNF-alpha) for SWNTC-COOH delivery system. SWNTC-COOH we have been showed to have to be an efficient carrier system. The results from the inhibition of gene expresion for both transfection systems were confirmed at protein level. Overall, the lowest mRNA expression was confirmed at protein level, especially in the case of p53 siRNA and TNF-alpha siRNA transfection. Less efficient reduction protein expressions were observed in the case of VEGF siRNA, for both transfection systems at 24 h; only at 48 h, there was a statistically significant reduction of VEGF protein expression. SWCNT-COOH determined an efficient delivery of siRNA. SWNTC-COOH, combined with suitable tumor markers like p53 siRNA, TNFalpha siRNA or VEGF siRNA can be used for the efficient delivery of siRNA.

  18. Water Purification Systems

    Science.gov (United States)

    1994-01-01

    Clearwater Pool Technologies employs NASA-developed silver/copper ionization to purify turtle and dolphin tanks, cooling towers, spas, water recycling systems, etc. The pool purifier consists of a microcomputer to monitor water conditions, a pair of metallic electrodes, and a rheostat controller. Ions are generated by passing a low voltage current through the electrodes; the silver ions kill the bacteria, and the copper ions kill algae. This technology has found broad application because it offers an alternative to chemical disinfectants. It was originally developed to purify water on Apollo spacecraft. Caribbean Clear has been using NASA's silver ionization technology for water purification for more than a decade. Two new products incorporate advancements of the basic technology. One is the AquaKing, a system designed for areas with no source of acceptable drinking water. Another is the Caribbean Clear Controller, designed for commercial pool and water park applications where sanitizing is combined with feedback control of pH and an oxidizer, chlorine or bromine. The technology was originally developed to purify water on Apollo spacecraft.

  19. Liquid metal purification device

    International Nuclear Information System (INIS)

    Sakai, Takao; Shimoyashiki, Shigehiro.

    1992-01-01

    The device of the present invention concerns a liquid metal purification device for removing and purifying impuries in liquid metal sodium used as coolants of an FBR type reactor. A vessel having a group of pipes made of hydrogen permeable metal at the inside thereof is disposed to the inlet pipeline of a cold trap. The group of hydrogen permeable metal pipes is connected to an exhaust pipe and a vacuum pump, so that the inside of the pipes is exhausted. Liquid metal sodium branched from the main pipeline of a coolant system passes through the outer side of the group of the hydrogen permeable metal pipes. In this cae, hydrogen contained as impurities in the liquid metal sodium diffuses and permeates the hydrogen permeation metal pipes and enters into the pipe group and is discharged out of the system by the vacuum pump. This can mitigate the hydrogen removing burden of the cold trap, to extend the device life time. (I.N.)

  20. The method of purification of waste water of NPS from petroleum oil using UV-radiation

    International Nuclear Information System (INIS)

    Kulemin, V.V.; Kareta, V.I.

    1993-01-01

    The main methods of concentration and purification of radioactive waste water of russian NPS are distillation and ion exchange. When waste water containing petroleum oil and washing matter is distillated, part of petroleum and washing matters go to the condensate. The purification of this condensate leads to pollution of ion exchange resins by petroleum oil and reduction of the filter cycle number. The purification of condensate of Russian NPS from petroleum oil is carried out using active carbon and polymer filters, but this process is not effective and fails to give pure condensate. Therefore, the authors began to search for more effective methods of purification of waste water from petroleum oil. They found that UV-radiation makes it possible to purify water from petroleum matter to concentration of the organic phase less than 0.5 mg/dm3. In this process of purification the air, contained in the water phase, was used as an oxidant. When purification is carried out in the absence of sorbents, the quantity of radioactive solid waste, which have to be recovered, decreases. During the study of purification of waste water it was found that increasing of the temperature of the process increases the rate of UV-radiation-induced oxidation of organic phase. The increase in the initial concentration of petroleum products also increases the rate of petroleum oil decomposition. The content of ions in water phase decreases the purification rate. The investigations were carried out on the laboratory scale with water and condensate from Tver's NPS

  1. SiRNAs in vivo imaging: methodology of fluorine-18 radiolabelling and application for the optimization of the siRNAs biodistribution and pharmaceutical properties; Imagerie in vivo des ARN interferentiels: methodologie de marquage au fluor-18 et application pour l'optimisation par imagerie de leur biodistribution et de leurs proprietes pharmacologiques

    Energy Technology Data Exchange (ETDEWEB)

    Viel, Th

    2008-01-15

    As RNA interference is a natural process which enables eukaryote cells to regulate the gene expressions, to control transposons, and to struggle against some viruses, two imagery techniques have been used in this research, i.e. optical imagery and Positron Emission Tomography (PET) imagery, to study the various modifications of the small interferential RNAs (siRNA). Different chemically modified siRNAs have been prepared and their in vitro activity, their in vivo metabolism (by HPLC analysis), their bio-distribution and their pharmacokinetic properties (by PET imagery) after marking them with fluorine-18. Their in vivo activity has been assessed by optical imagery.

  2. Defining process design space for a hydrophobic interaction chromatography (HIC) purification step: application of quality by design (QbD) principles.

    Science.gov (United States)

    Jiang, Canping; Flansburg, Lisa; Ghose, Sanchayita; Jorjorian, Paul; Shukla, Abhinav A

    2010-12-15

    The concept of design space has been taking root under the quality by design paradigm as a foundation of in-process control strategies for biopharmaceutical manufacturing processes. This paper outlines the development of a design space for a hydrophobic interaction chromatography (HIC) process step. The design space included the impact of raw material lot-to-lot variability and variations in the feed stream from cell culture. A failure modes and effects analysis was employed as the basis for the process characterization exercise. During mapping of the process design space, the multi-dimensional combination of operational variables were studied to quantify the impact on process performance in terms of yield and product quality. Variability in resin hydrophobicity was found to have a significant influence on step yield and high-molecular weight aggregate clearance through the HIC step. A robust operating window was identified for this process step that enabled a higher step yield while ensuring acceptable product quality. © 2010 Wiley Periodicals, Inc.

  3. HIVsirDB: a database of HIV inhibiting siRNAs.

    Directory of Open Access Journals (Sweden)

    Atul Tyagi

    Full Text Available Human immunodeficiency virus (HIV is responsible for millions of deaths every year. The current treatment involves the use of multiple antiretroviral agents that may harm patients due to their toxic nature. RNA interference (RNAi is a potent candidate for the future treatment of HIV, uses short interfering RNA (siRNA/shRNA for silencing HIV genes. In this study, attempts have been made to create a database HIVsirDB of siRNAs responsible for silencing HIV genes.HIVsirDB is a manually curated database of HIV inhibiting siRNAs that provides comprehensive information about each siRNA or shRNA. Information was collected and compiled from literature and public resources. This database contains around 750 siRNAs that includes 75 partially complementary siRNAs differing by one or more bases with the target sites and over 100 escape mutant sequences. HIVsirDB structure contains sixteen fields including siRNA sequence, HIV strain, targeted genome region, efficacy and conservation of target sequences. In order to facilitate user, many tools have been integrated in this database that includes; i siRNAmap for mapping siRNAs on target sequence, ii HIVsirblast for BLAST search against database, iii siRNAalign for aligning siRNAs.HIVsirDB is a freely accessible database of siRNAs which can silence or degrade HIV genes. It covers 26 types of HIV strains and 28 cell types. This database will be very useful for developing models for predicting efficacy of HIV inhibiting siRNAs. In summary this is a useful resource for researchers working in the field of siRNA based HIV therapy. HIVsirDB database is accessible at http://crdd.osdd.net/raghava/hivsir/.

  4. Gold nanoparticle mediated laser transfection for efficient siRNA mediated gene knock down.

    Directory of Open Access Journals (Sweden)

    Dag Heinemann

    Full Text Available Laser based transfection methods have proven to be an efficient and gentle alternative to established molecule delivery methods like lipofection or electroporation. Among the laser based methods, gold nanoparticle mediated laser transfection bears the major advantage of high throughput and easy usability. This approach uses plasmon resonances on gold nanoparticles unspecifically attached to the cell membrane to evoke transient and spatially defined cell membrane permeabilization. In this study, we explore the parameter regime for gold nanoparticle mediated laser transfection for the delivery of molecules into cell lines and prove its suitability for siRNA mediated gene knock down. The developed setup allows easy usage and safe laser operation in a normal lab environment. We applied a 532 nm Nd:YAG microchip laser emitting 850 ps pulses at a repetition rate of 20.25 kHz. Scanning velocities of the laser spot over the sample of up to 200 mm/s were tested without a decline in perforation efficiency. This velocity leads to a process speed of ∼8 s per well of a 96 well plate. The optimal particle density was determined to be ∼6 particles per cell using environmental scanning electron microscopy. Applying the optimized parameters transfection efficiencies of 88% were achieved in canine pleomorphic adenoma ZMTH3 cells using a fluorescent labeled siRNA while maintaining a high cell viability of >90%. Gene knock down of d2-EGFP was demonstrated and validated by fluorescence repression and western blot analysis. On basis of our findings and established mathematical models we suppose a mixed transfection mechanism consisting of thermal and multiphoton near field effects. Our findings emphasize that gold nanoparticle mediated laser transfection provides an excellent tool for molecular delivery for both, high throughput purposes and the transfection of sensitive cells types.

  5. Gold nanoparticle mediated laser transfection for efficient siRNA mediated gene knock down.

    Science.gov (United States)

    Heinemann, Dag; Schomaker, Markus; Kalies, Stefan; Schieck, Maximilian; Carlson, Regina; Murua Escobar, Hugo; Ripken, Tammo; Meyer, Heiko; Heisterkamp, Alexander

    2013-01-01

    Laser based transfection methods have proven to be an efficient and gentle alternative to established molecule delivery methods like lipofection or electroporation. Among the laser based methods, gold nanoparticle mediated laser transfection bears the major advantage of high throughput and easy usability. This approach uses plasmon resonances on gold nanoparticles unspecifically attached to the cell membrane to evoke transient and spatially defined cell membrane permeabilization. In this study, we explore the parameter regime for gold nanoparticle mediated laser transfection for the delivery of molecules into cell lines and prove its suitability for siRNA mediated gene knock down. The developed setup allows easy usage and safe laser operation in a normal lab environment. We applied a 532 nm Nd:YAG microchip laser emitting 850 ps pulses at a repetition rate of 20.25 kHz. Scanning velocities of the laser spot over the sample of up to 200 mm/s were tested without a decline in perforation efficiency. This velocity leads to a process speed of ∼8 s per well of a 96 well plate. The optimal particle density was determined to be ∼6 particles per cell using environmental scanning electron microscopy. Applying the optimized parameters transfection efficiencies of 88% were achieved in canine pleomorphic adenoma ZMTH3 cells using a fluorescent labeled siRNA while maintaining a high cell viability of >90%. Gene knock down of d2-EGFP was demonstrated and validated by fluorescence repression and western blot analysis. On basis of our findings and established mathematical models we suppose a mixed transfection mechanism consisting of thermal and multiphoton near field effects. Our findings emphasize that gold nanoparticle mediated laser transfection provides an excellent tool for molecular delivery for both, high throughput purposes and the transfection of sensitive cells types.

  6. Nanostructures to modulate vascular inflammation: Multifunctional nanoparticles for quantifiable siRNA delivery and molecular imaging

    Science.gov (United States)

    Kaneda, Megan Marie

    Early steps in the progression of inflammatory diseases such as atherosclerosis involve the recruitment of leukocytes to the vascular endothelium through the expression or up-regulation of adhesion molecules. These adhesion molecules are critical mediators of leukocyte attachment and subsequent extravasation through transendothelial migration. One of these adhesion molecules, vascular cell adhesion molecule-1 (VCAM-1) is particularly attractive as a marker of early atherosclerotic activity due to its low expression level on normal endothelium and up-regulation prior to and during the development of early lesions. With this in mind, the purpose of this thesis was to develop nanostructures for the detection and down-regulation of adhesion molecules by the vascular endothelium. To detect early inflammation we designed a perfluorocarbon nanoparticle (PFC-NP) probe, which was used for in vivo targeting of VCAM-1. Nanoparticles were detected ex vivo by the magnetic resonance (MR) signature from the fluorine core of the particle. Nanoparticles accumulated in tissues characterized by early inflammatory processes. To down-regulate VCAM-1 expression by vascular endothelial cells, cationic PFC-NP were produced through the addition of the cationic lipid 1,2-Dioleoyl-3-Trimethylammonium-Propane. Cationic PFC-NP were able to deliver anti-VCAM-1 siRNA to endothelial cells through a non-standard lipid raft mediated endocytic pathway. VCAM-1 levels were significantly reduced in treated cells indicating that this delivery mechanism may be advantageous for delivery of cargo into the cytoplasm. Using the fluorine signature from the core of the cationic PFC-NP, we were able to quantify and localize this siRNA delivery agent both in vitro and in vivo. The ability to quantify the local concentrations of these particles could be of great benefit for estimating local drug concentrations and developing new pharmacokinetic and pharmacodynamic paradigms to describe this new class of

  7. Gold Nanoparticle Mediated Laser Transfection for Efficient siRNA Mediated Gene Knock Down

    Science.gov (United States)

    Heinemann, Dag; Schomaker, Markus; Kalies, Stefan; Schieck, Maximilian; Carlson, Regina; Escobar, Hugo Murua; Ripken, Tammo; Meyer, Heiko; Heisterkamp, Alexander

    2013-01-01

    Laser based transfection methods have proven to be an efficient and gentle alternative to established molecule delivery methods like lipofection or electroporation. Among the laser based methods, gold nanoparticle mediated laser transfection bears the major advantage of high throughput and easy usability. This approach uses plasmon resonances on gold nanoparticles unspecifically attached to the cell membrane to evoke transient and spatially defined cell membrane permeabilization. In this study, we explore the parameter regime for gold nanoparticle mediated laser transfection for the delivery of molecules into cell lines and prove its suitability for siRNA mediated gene knock down. The developed setup allows easy usage and safe laser operation in a normal lab environment. We applied a 532 nm Nd:YAG microchip laser emitting 850 ps pulses at a repetition rate of 20.25 kHz. Scanning velocities of the laser spot over the sample of up to 200 mm/s were tested without a decline in perforation efficiency. This velocity leads to a process speed of ∼8 s per well of a 96 well plate. The optimal particle density was determined to be ∼6 particles per cell using environmental scanning electron microscopy. Applying the optimized parameters transfection efficiencies of 88% were achieved in canine pleomorphic adenoma ZMTH3 cells using a fluorescent labeled siRNA while maintaining a high cell viability of >90%. Gene knock down of d2-EGFP was demonstrated and validated by fluorescence repression and western blot analysis. On basis of our findings and established mathematical models we suppose a mixed transfection mechanism consisting of thermal and multiphoton near field effects. Our findings emphasize that gold nanoparticle mediated laser transfection provides an excellent tool for molecular delivery for both, high throughput purposes and the transfection of sensitive cells types. PMID:23536802

  8. Rapid purification of recombinant histones.

    Science.gov (United States)

    Klinker, Henrike; Haas, Caroline; Harrer, Nadine; Becker, Peter B; Mueller-Planitz, Felix

    2014-01-01

    The development of methods to assemble nucleosomes from recombinant histones decades ago has transformed chromatin research. Nevertheless, nucleosome reconstitution remains time consuming to this day, not least because the four individual histones must be purified first. Here, we present a streamlined purification protocol of recombinant histones from bacteria. We termed this method "rapid histone purification" (RHP) as it circumvents isolation of inclusion bodies and thereby cuts out the most time-consuming step of traditional purification protocols. Instead of inclusion body isolation, whole cell extracts are prepared under strongly denaturing conditions that directly solubilize inclusion bodies. By ion exchange chromatography, the histones are purified from the extracts. The protocol has been successfully applied to all four canonical Drosophila and human histones. RHP histones and histones that were purified from isolated inclusion bodies had similar purities. The different purification strategies also did not impact the quality of octamers reconstituted from these histones. We expect that the RHP protocol can be readily applied to the purification of canonical histones from other species as well as the numerous histone variants.

  9. RELIGION AND PURIFICATION OF SOUL

    Directory of Open Access Journals (Sweden)

    Azam Khodashenas Pelko

    2010-11-01

    Full Text Available The Jainism emphasizes three major teachings about the purification of the soul (jiva, Ahimsa, Aparigrapha and anekantwad. Jainism, The focus of this religion has been purification of the soul by means of right conduct, right faith and right knowledge. The ultimate goal of Hinduism is Moksha or liberation (total freedom. In Hinduism, purification of the soul is a goal that one must work to attain. The Buddhism is the science of pursuing the aim of making the human mind perfect, and of purifying the human soul. The knowledge of purifying of the soul and softening of the hearts is as essential for human. They having the correct motivations means purifying our souls from hypocrisy, caprice, and heedlessness. The primary goal of Taoism may be described as the mystical intuition of the Tao, which is the way, the undivided unity, and the ultimate Reality. According to the Christianity access to truth cannot be conceived without purity of the soul

  10. Antimicrobial Peptide Production and Purification.

    Science.gov (United States)

    Suda, Srinivas; Field, Des; Barron, Niall

    2017-01-01

    Antimicrobial peptides (AMPs) are natural defense compounds which are synthesized as ribosomal gene-encoded pre-peptides and produced by all living organisms. AMPs are small peptides, usually cationic and typically have hydrophobic residues which interact with cell membranes and have either a narrow or broad spectrum of biological activity. AMPs are isolated from the natural host or heterologously expressed in other hosts such as Escherichia coli. The proto-typical lantibiotic Nisin is a widely used AMP that is produced by the food-grade organism Lactococcus lactis. Although AMP production and purification procedures require optimization for individual AMPs, the Nisin production and purification protocol outlined in this chapter can be easily applied with minor modifications for the production and purification of other lantibiotics or AMPs. While Nisin is produced and secreted into the supernatant, steps to recover Nisin from both cell-free supernatant and cell pellet are outlined in detail.

  11. Targeted transfection increases siRNA uptake and gene silencing of primary endothelial cells in vitro - A quantitative study

    NARCIS (Netherlands)

    Asgeirsdottir, Sigridur A.; Talman, Eduard G.; de Graaf, Inge A.; Kamps, Jan A. A. M.; Satchell, Simon C.; Mathieson, Peter W.; Ruiters, Marcel H. J.; Molema, Grietje

    2010-01-01

    Applications of small-interfering RNA (siRNA) call for specific and efficient delivery of siRNA into particular cell types. We developed a novel, non-viral targeting system to deliver siRNA specifically into inflammation-activated endothelial cells. This was achieved by conjugating the cationic

  12. IN VIVO SCREENING OF CHEMICAL MODIFICATIONS OF siRNAs FOR EFFECT ON THE INNATE IMMUNE RESPONSE IN FISH

    DEFF Research Database (Denmark)

    Lorenzen, Niels; Schyth, Brian Dall; Bramsen, J. B.

    Abstract Due to their sequence specific gene silencing activity siRNAs are regarded as promising new active compounds in gene medicine and functional studies. But one serious problem with delivering siRNAs as treatment is the now well-established non-specific activities of some RNAs duplexes. Cel...... of siRNAs into RISC for specific gene silencing....

  13. What is required for purification and processing of biogas to the natural gas standard?; Was brauchen wir zur Reinigung/Aufbereitung von Biogas zu Erdgasqualitaet

    Energy Technology Data Exchange (ETDEWEB)

    Tentscher, W. [eco Naturgas Handels GmbH, Berlin (Germany)

    2002-07-01

    The most common gas scrubbing process in Europe, i.e. the wet scrubbing process, is described. Preliminary stages are coarse filtering, coarse dehydration and coarse desulphurisation. Carbon dioxide and hydrogen sulphide are absorbed in counterflow in water at a pressure of 6 to 10 bar. The water can be generated by pressure relief and can be recirculated. Plant components like compressors, absorption column, strippers and dryers are gone into as well as the mode of operation and control. [German] Das europaweit zur Aufbereitung von Biogas am meisten genutzte Verfahren der nassen Gaswaesche wird beschrieben. Vorausgehende Reinigungsschritte des Biogases sind Grobfilterung, Grobentfeuchtung und Grobentschwefelung. Kohlendioxid und gleichzeitig H{sub 2}S werden im Gegenstrom unter Druck von 6 bis 10 bar in Wasser absorbiert. Das Wasser kann durch Entspannung regeneriert und im Kreislauf gefuehrt werden. Auf die Komponenten der Anlage wie Kompressor, Absorptionskolonne, Stripper und Trockner wird ebenso eingegangen wie auf die Betriebsfuehrung und Steuerung. (orig.)

  14. Dry syngas purification process for coal gas produced in oxy-fuel type integrated gasification combined cycle power generation with carbon dioxide capturing feature.

    Science.gov (United States)

    Kobayashi, Makoto; Akiho, Hiroyuki

    2017-12-01

    Electricity production from coal fuel with minimizing efficiency penalty for the carbon dioxide abatement will bring us sustainable and compatible energy utilization. One of the promising options is oxy-fuel type Integrated Gasification Combined Cycle (oxy-fuel IGCC) power generation that is estimated to achieve thermal efficiency of 44% at lower heating value (LHV) base and provide compressed carbon dioxide (CO 2 ) with concentration of 93 vol%. The proper operation of the plant is established by introducing dry syngas cleaning processes to control halide and sulfur compounds satisfying tolerate contaminants level of gas turbine. To realize the dry process, the bench scale test facility was planned to demonstrate the first-ever halide and sulfur removal with fixed bed reactor using actual syngas from O 2 -CO 2 blown gasifier for the oxy-fuel IGCC power generation. Design parameter for the test facility was required for the candidate sorbents for halide removal and sulfur removal. Breakthrough test was performed on two kinds of halide sorbents at accelerated condition and on honeycomb desulfurization sorbent at varied space velocity condition. The results for the both sorbents for halide and sulfur exhibited sufficient removal within the satisfactory short depth of sorbent bed, as well as superior bed conversion of the impurity removal reaction. These performance evaluation of the candidate sorbents of halide and sulfur removal provided rational and affordable design parameters for the bench scale test facility to demonstrate the dry syngas cleaning process for oxy-fuel IGCC system as the scaled up step of process development. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Experimental Study on Purification of Low Grade Diatomite

    Science.gov (United States)

    Xiao, Liguang; Pang, Bo

    2017-04-01

    This paper presented an innovation for purification of low grade diatomite(DE) by grinding, ultrasonic pretreatment, acid leaching of closed stirring and calcination. The optimum process parameters of DE purification were obtained, the characterizations of original and purified DE were determined by SEM and BET. The results showed that the specific surface area of DE increased from 12.65m2/g to 23.23m2/g, which increased by 45.54%. SEM analysis revealed that the pore structure of purified DE was dredged highly.

  16. Partial Purification and Characterization of Extracellular Protease ...

    African Journals Online (AJOL)

    Nigerian Journal of Basic and Applied Sciences ... Purification of the enzyme by gel filtration chromatography on Sephadex G75 following ammonium sulphate precipitation gave 2.26 fold increase in purification with specific activity of 46.13 units/mg protein while purification on Sephadex CM50 resulted in reduced ...

  17. Purification of Water by Aquatic Plants

    OpenAIRE

    Morimitsu, Katsuhito; Kawahigashi, Tatsuo

    2013-01-01

    [Abstract] Water quality purification of many water systems including those occurring in rivers depends to a great degree on water quality purification activities of aquatic plants and microbes. This paper presents a discussion of results, based on laboratory experiments, of purification by aquatic plants.

  18. Novel peptide ligand with high binding capacity for antibody purification

    DEFF Research Database (Denmark)

    Lund, L. N.; Gustavsson, P. E.; Michael, R.

    2012-01-01

    Small synthetic ligands for protein purification have become increasingly interesting with the growing need for cheap chromatographic materials for protein purification and especially for the purification of monoclonal antibodies (mAbs). Today, Protein A-based chromatographic resins are the most...... commonly used capture step in mAb down stream processing; however, the use of Protein A chromatography is less attractive due to toxic ligand leakage as well as high cost. Whether used as an alternative to the Protein A chromatographic media or as a subsequent polishing step, small synthetic peptide...... ligands have an advantage over biological ligands; they are cheaper to produce, ligand leakage by enzymatic degradation is either eliminated or significantly reduced, and they can in general better withstand cleaning in place (CIP) conditions such as 0.1 M NaOH. Here, we present a novel synthetic peptide...

  19. Bromelain: an overview of industrial application and purification strategies.

    Science.gov (United States)

    Arshad, Zatul Iffah Mohd; Amid, Azura; Yusof, Faridah; Jaswir, Irwandi; Ahmad, Kausar; Loke, Show Pau

    2014-09-01

    This review highlights the use of bromelain in various applications with up-to-date literature on the purification of bromelain from pineapple fruit and waste such as peel, core, crown, and leaves. Bromelain, a cysteine protease, has been exploited commercially in many applications in the food, beverage, tenderization, cosmetic, pharmaceutical, and textile industries. Researchers worldwide have been directing their interest to purification strategies by applying conventional and modern approaches, such as manipulating the pH, affinity, hydrophobicity, and temperature conditions in accord with the unique properties of bromelain. The amount of downstream processing will depend on its intended application in industries. The breakthrough of recombinant DNA technology has facilitated the large-scale production and purification of recombinant bromelain for novel applications in the future.

  20. Random small interfering RNA library screen identifies siRNAs that induce human erythroleukemia cell differentiation.

    Science.gov (United States)

    Fan, Cuiqing; Xiong, Yuan; Zhu, Ning; Lu, Yabin; Zhang, Jiewen; Wang, Song; Liang, Zicai; Shen, Yan; Chen, Meihong

    2011-03-01

    Cancers are characterized by poor differentiation. Differentiation therapy is a strategy to alleviate malignant phenotypes by inducing cancer cell differentiation. Here we carried out a combinatorial high-throughput screen with a random siRNA library on human erythroleukemia K-562 cell differentiation. Two siRNAs screened from the library were validated to be able to induce erythroid differentiation to varying degrees, determined by CD235 and globin up-regulation, GATA-2 down-regulation, and cell growth inhibition. The screen we performed here is the first trial of screening cancer differentiation-inducing agents from a random siRNA library, demonstrating that a random siRNA library can be considered as a new resource in efforts to seek new therapeutic agents for cancers. As a random siRNA library has a broad coverage for the entire genome, including known/unknown genes and protein coding/non-coding sequences, screening using a random siRNA library can be expected to greatly augment the repertoire of therapeutic siRNAs for cancers.

  1. Antineoplastic Effects of siRNA against TMPRSS2-ERG Junction Oncogene in Prostate Cancer.

    Directory of Open Access Journals (Sweden)

    Giorgia Urbinati

    Full Text Available TMPRSS2-ERG junction oncogene is present in more than 50% of patients with prostate cancer and its expression is frequently associated with poor prognosis. Our aim is to achieve gene knockdown by siRNA TMPRSS2-ERG and then to assess the biological consequences of this inhibition. First, we designed siRNAs against the two TMPRSS2-ERG fusion variants (III and IV, most frequently identified in patients' biopsies. Two of the five siRNAs tested were found to efficiently inhibit mRNA of both TMPRSS2-ERG variants and to decrease ERG protein expression. Microarray analysis further confirmed ERG inhibition by both siRNAs TMPRSS2-ERG and revealed one common down-regulated gene, ADRA2A, involved in cell proliferation and migration. The siRNA against TMPRSS2-ERG fusion variant IV showed the highest anti-proliferative effects: Significantly decreased cell viability, increased cleaved caspase-3 and inhibited a cluster of anti-apoptotic proteins. To propose a concrete therapeutic approach, siRNA TMPRSS2-ERG IV was conjugated to squalene, which can self-organize as nanoparticles in water. The nanoparticles of siRNA TMPRSS2-ERG-squalene injected intravenously in SCID mice reduced growth of VCaP xenografted tumours, inhibited oncoprotein expression and partially restored differentiation (decrease in Ki67. In conclusion, this study offers a new prospect of treatment for prostate cancer based on siRNA-squalene nanoparticles targeting TMPRSS2-ERG junction oncogene.

  2. Therapeutic Effects of Myeloid Cell Leukemia-1 siRNA on Human Acute Myeloid Leukemia Cells

    Directory of Open Access Journals (Sweden)

    Hadi Karami

    2014-05-01

    Full Text Available Purpose: Up-regulation of Mcl-1, a known anti-apoptotic protein, is associated with the survival and progression of various malignancies including leukemia. The aim of this study was to explore the effect of Mcl-1 small interference RNA (siRNA on the proliferation and apoptosis of HL-60 acute myeloid leukemia (AML cells. Methods: siRNA transfection was performed using Lipofectamine™2000 reagent. Relative mRNA and protein expressions were quantified by quantitative real-time PCR and Western blotting, respectively. Trypan blue assay was performed to assess tumor cell proliferation after siRNA transfection. The cytotoxic effect of Mcl-1 siRNA on leukemic cells was measured using MTT assay. Apoptosis was detected using ELISA cell death assay. Results: Mcl-1 siRNA clearly lowered both Mcl-1 mRNA and protein levels in a time-dependent manner, leading to marked inhibition of cell survival and proliferation. Furthermore, Mcl-1 down-regulation significantly enhanced the extent of HL-60 apoptotic cells. Conclusion: Our results suggest that the down-regulation of Mcl-1 by siRNA can effectively trigger apoptosis and inhibit the proliferation of leukemic cells. Therefore, Mcl-1 siRNA may be a potent adjuvant in AML therapy.

  3. Cancer-targeting siRNA delivery from porous silicon nanoparticles.

    Science.gov (United States)

    Wan, Yuan; Apostolou, Sinoula; Dronov, Roman; Kuss, Bryone; Voelcker, Nicolas H

    2014-10-01

    Porous silicon nanoparticles (pSiNPs) with tunable pore size are biocompatible and biodegradable, suggesting that they are suitable biomaterials as vehicles for drug delivery. Loading of small interfering RNA (siRNA) into the pores of pSiNPs can protect siRNA from degradation as well as improve the cellular uptake. We aimed to deliver MRP1 siRNA loaded into pSiNPs to glioblastoma cells, and to demonstrate downregulation of MRP1 at the mRNA and protein levels. 50-220 nm pSiNPs with an average pore size of 26 nm were prepared, followed by electrostatic adsorption of siRNA into pores. Oligonucleotide loading and release profiles were investigated; MRP1 mRNA and protein expression, cell viability and cell apoptosis were studied. Approximately 7.7 µg of siRNA was loaded per mg of pSiNPs. Cells readily took up nanoparticles after 30 min incubation. siRNA-loaded pSiNPs were able to effectively downregulate target mRNA (~40%) and protein expression (31%), and induced cell apoptosis and necrosis (33%). siRNA loaded pSiNPs downregulated mRNA and protein expression and induced cell death. This novel siRNA delivery system may pave the way towards developing more effective tumor therapies.

  4. Synthesis and characterization of amino acid-functionalized calcium phosphate nanoparticles for siRNA delivery.

    Science.gov (United States)

    Bakan, Feray; Kara, Goknur; Cokol Cakmak, Melike; Cokol, Murat; Denkbas, Emir Baki

    2017-10-01

    Small interfering RNAs (siRNA) are short nucleic acid fragments of about 20-27 nucleotides, which can inhibit the expression of specific genes. siRNA based RNAi technology has emerged as a promising method for the treatment of a variety of diseases. However, a major limitation in the therapeutic use of siRNA is its rapid degradation in plasma and cellular cytoplasm, resulting in short half-life. In addition, as siRNA molecules cannot penetrate into the cell efficiently, it is required to use a carrier system for its delivery. In this work, chemically and morphologically different calcium phosphate (CaP) nanoparticles, including spherical-like hydroxyapatite (HA-s), needle-like hydroxyapatite (HA-n) and calcium deficient hydroxyapatite (CDHA) nanoparticles were synthesized by the sol-gel technique and the effects of particle characteristics on the binding capacity of siRNA were investigated. In order to enhance the gene loading efficiency, the nanoparticles were functionalized with arginine and the morphological and their structural characteristics were analyzed. The addition of arginine did not significantly change the particle sizes; however, it provided a significantly increased binding of siRNA for all types of CaP nanoparticles, as revealed by spectrophotometric measurements analysis. Arginine functionalized HA-n nanoparticles showed the best binding behavior with siRNA among the other nanoparticles due to its high, positive zeta potential (+18.8mV) and high surface area of Ca ++ rich "c" plane. MTT cytotoxicity assays demonstrated that all the nanoparticles tested herein were biocompatible. Our results suggest that high siRNA entrapment in each of the three modified non-toxic CaP nanoparticles make them promising candidates as a non-viral vector for delivering therapeutic siRNA molecules to treat cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. The Combination Process for Preparative Separation and Purification of Paclitaxel and 10-Deacetylbaccatin III Using Diaion® Hp-20 Followed by Hydrophilic Interaction Based Solid Phase Extraction

    Science.gov (United States)

    Shirshekanb, Mahsa; Rezadoost, Hassan; Javanbakht, Mehran; Ghassempour, Ali Reza

    2017-01-01

    There is no other naturally occurring defense agent against cancer that has a stronger effect than paclitaxel, commonly known under the brand name of Taxol®. The major drawback for the more widespread use of paclitaxel and its precious precursor, 10-deacetylbaccatin III (10-DAB III), is that they require large-scale extraction from different parts of yew trees (Taxus species), cell cultures, taxane-producing endophytic fungi, and Corylus species. In our previous work, a novel online two-dimensional heart-cut liquid chromatography process using hydrophilic interaction/ reversed-phase chromatography was used to introduce a semi-preparative treatment for the separation of polar (10-deacetylbaccatin III) and non-polar (paclitaxel) taxanes from Taxus baccata L. In this work, a combination of the absorbent (Diaion® HP-20) and a silica based solid phase extraction is utilized as a new, efficient, and cost effective method for large-scale production of taxanes. This process avoids the technical problem of two-dimensional preparative liquid chromatography. The first stage of the process involves discarding co-extractive polar compounds including chlorophylls and pigments using a non-polar synthetic hydrophobic absorbent, Diaion® HP-20. Extract was then loaded on to a silica based hydrophilic interaction solid phase extraction (silica 40-60 micron). Taxanes was eluted using a mixture of water and methanol at the optimized ratio of 70:30. Finally, the fraction containing taxanes was applied to semi-preparative reversed phase HPLC. The results revealed that using this procedure, paclitaxel and 10-DAB III could be obtained at 8 and 3 times more, respectively than by the traditional method of extraction. PMID:29552048

  6. The Combination Process for Preparative Separation and Purification of Paclitaxel and 10-Deacetylbaccatin III Using Diaion® Hp-20 Followed by Hydrophilic Interaction Based Solid Phase Extraction.

    Science.gov (United States)

    Shirshekanb, Mahsa; Rezadoost, Hassan; Javanbakht, Mehran; Ghassempour, Ali Reza

    2017-01-01

    There is no other naturally occurring defense agent against cancer that has a stronger effect than paclitaxel, commonly known under the brand name of Taxol ® . The major drawback for the more widespread use of paclitaxel and its precious precursor, 10-deacetylbaccatin III (10-DAB III), is that they require large-scale extraction from different parts of yew trees ( Taxus species), cell cultures, taxane-producing endophytic fungi, and Corylus species. In our previous work, a novel online two-dimensional heart-cut liquid chromatography process using hydrophilic interaction/ reversed-phase chromatography was used to introduce a semi-preparative treatment for the separation of polar (10-deacetylbaccatin III) and non-polar (paclitaxel) taxanes from Taxus baccata L. In this work, a combination of the absorbent (Diaion ®  HP-20) and a silica based solid phase extraction is utilized as a new, efficient, and cost effective method for large-scale production of taxanes. This process avoids the technical problem of two-dimensional preparative liquid chromatography. The first stage of the process involves discarding co-extractive polar compounds including chlorophylls and pigments using a non-polar synthetic hydrophobic absorbent, Diaion ®  HP-20. Extract was then loaded on to a silica based hydrophilic interaction solid phase extraction (silica 40-60 micron). Taxanes was eluted using a mixture of water and methanol at the optimized ratio of 70:30. Finally, the fraction containing taxanes was applied to semi-preparative reversed phase HPLC. The results revealed that using this procedure, paclitaxel and 10-DAB III could be obtained at 8 and 3 times more, respectively than by the traditional method of extraction.

  7. Optimization of the purification process of wine lees through anaerobic filter reactors. Optimizacion del proceso de depuracion de vinazas de vino mediante reactores tipo filtro anaerobio

    Energy Technology Data Exchange (ETDEWEB)

    Nebot Sanz, E.; Romero Garcia, L.I.; Quiroga Alonso, J.M.; Sales Marquez, D. (Departamento de Ingenieria Quimica, Universidad de Cadiz, Cadiz (Spain))

    1994-01-01

    In this work, the optimization of thermophilic anaerobic process, using Anaerobic Filter technology was studied. Feed of the Anaerobic Filter was wine-distillery wastewaters. The experiments developed were carried out at lab-scale downflow anaerobic filter reactors. Reactors were filled with a high porous plastic media (Flocor-R). The media support entities have a high surface/volume ratio. Test were run to determine the maximum organic load attainable in the system for wich both, the depurative efficiency and the methane production were optimum. Likewise, the effect of organic load on the anaerobic filter performance were studied. (Author) 15 refs. (Author)

  8. Purification Simulation With Vapor Permeation and Distillation-Adsorption In Bioethanol Plant

    OpenAIRE

    Misri Gozan; Mia Sari Setiawan; Kenny Lischer

    2017-01-01

    High purity of Bioethanol is required in biofuel mixing with gasoline (EXX). In bioethanol production line, the azeotropic property of ethanol-water becomes the barrier for purification process. This study examined two bioethanol separation processes by support of simulation tools, Superpro Designer 9.0 software. Ethanol purity and a low costeconomical process were the major considerations. Purification method of vapor permeation membrane technology was compared with distillation-adsorption m...

  9. Optimized conditions for high-level solubilization and purification of ...

    African Journals Online (AJOL)

    NH Computers

    2011-10-10

    Oct 10, 2011 ... filtration chromatography using Sephadex G-50 column. The purified protein was refolded by .... blocking with BSA, the nitrocellulose membrane was processed using rabbit monoclonal antibody raised ..... recombinant human growth hormone using radial flow chromatography. Protein Exp. Purif., 68: 54-59.

  10. Purification of HGI2 for nuclear detector fabrication

    International Nuclear Information System (INIS)

    Schieber, M.M.

    1978-01-01

    A process for purification of mercuric iodide (HgI 2 ) to be used as a source material for the growth of detector quality crystals. The high purity HgI 2 raw material is produced by a combination of three stages: synthesis of HgI 2 from Hg and I 2 , repeated sublimation, and zone refining

  11. Chromatographic and electrophoretic methods for nanodisc purification and analysis

    DEFF Research Database (Denmark)

    Justesen, Bo Højen; Günther-Pomorski, Thomas

    2014-01-01

    Soluble nanoscale lipid bilayers, termed nanodiscs, are widely used in science for studying the membrane-anchored and integral membrane protein complexes under defined experimental conditions. Although their formation occurs by a self-assembly process, nanodisc purification and the verification...

  12. Energy Efficient Bioethanol Purification by Heat Pump Assisted Extractive Distillation

    NARCIS (Netherlands)

    Kiss, Anton A.; Luo, Hao; Bildea, Costin Sorin

    2015-01-01

    The purification of bioethanol fuel requires an energy demanding separation process to concentrate the diluted streams obtained in the fermentation stage and to overcome the azeotropic behaviour of ethanol-water mixture. The classic separation sequence consists of three distillation columns that

  13. Novel heat-pump-assisted extractive distillation for bioethanol purification

    NARCIS (Netherlands)

    Luo, Hao; Bildea, Costin Sorin; Kiss, Anton A.

    2015-01-01

    The purification of bioethanol fuel involves an energy-intensive separation process to concentrate the diluted streams obtained in the fermentation stage and to overcome the azeotropic behavior of the ethanol-water mixture. The conventional separation sequence employs three distillation columns that

  14. Magnetic purification of curcumin from Curcuma longa rhizome by novel naked maghemite nanoparticles.

    Science.gov (United States)

    Magro, Massimiliano; Campos, Rene; Baratella, Davide; Ferreira, Maria Izabela; Bonaiuto, Emanuela; Corraducci, Vittorino; Uliana, Maíra Rodrigues; Lima, Giuseppina Pace Pereira; Santagata, Silvia; Sambo, Paolo; Vianello, Fabio

    2015-01-28

    Naked maghemite nanoparticles, namely, surface active maghemite nanoparticles (SAMNs), characterized by a diameter of about 10 nm, possessing peculiar colloidal stability, surface chemistry, and superparamagnetism, present fundamental requisites for the development of effective magnetic purification processes for biomolecules in complex matrices. Polyphenolic molecules presenting functionalities with different proclivities toward iron chelation were studied as probes for testing SAMN suitability for magnetic purification. Thus, the binding efficiency and reversibility on SAMNs of phenolic compounds of interest in the pharmaceutical and food industries, namely, catechin, tyrosine, hydroxytyrosine, ferulic acid, coumaric acid, rosmarinic acid, naringenin, curcumin, and cyanidin-3-glucoside, were evaluated. Curcumin emerged as an elective compound, suitable for magnetic purification by SAMNs from complex matrices. A combination of curcumin, demethoxycurcumin, and bis-demethoxycurcumin was recovered by a single magnetic purification step from extracts of Curcuma longa rhizomes, with a purity >98% and a purification yield of 45%, curcumin being >80% of the total purified curcuminoids.

  15. Delivery systems and local administration routes for therapeutic siRNA.

    Science.gov (United States)

    Vicentini, Fabiana Testa Moura de Carvalho; Borgheti-Cardoso, Lívia Neves; Depieri, Lívia Vieira; de Macedo Mano, Danielle; Abelha, Thais Fedatto; Petrilli, Raquel; Bentley, Maria Vitória Lopes Badra

    2013-04-01

    With the increasing number of studies proposing new and optimal delivery strategies for the efficacious silencing of gene-related diseases by the local administration of siRNAs, the present review aims to provide a broad overview of the most important and latest developments of non-viral siRNA delivery systems for local administration. Moreover, the main disease targets for the local delivery of siRNA to specific tissues or organs, including the skin, the lung, the eye, the nervous system, the digestive system and the vagina, were explored.

  16. Elucidating the role of free polycations in gene knockdown by siRNA polyplexes

    DEFF Research Database (Denmark)

    Klauber, Thomas Christopher Bogh; Søndergaard, Rikke Vicki; Sawant, Rupa R.

    2016-01-01

    capability, but are very different regarding siRNA decondensation, cellular internalization and induction of reporter gene knockdown. Lipid conjugation of bPEI 1.8. kDa improves the siRNA delivery properties, but with markedly different formulation requirements and mechanisms of action compared...... today.A major reason for the lack of progress is insufficient understanding of cell-polyplex interaction. We investigate siRNA delivery using polyethyleneimine (PEI) based vectors and examine how crucial formulation parameters determine the challenges associated with PEI as a delivery vector. We further...

  17. Purification of crude glycerol from transesterification reaction of palm oil using direct method and multistep method

    Science.gov (United States)

    Nasir, N. F.; Mirus, M. F.; Ismail, M.

    2017-09-01

    Crude glycerol which produced from transesterification reaction has limited usage if it does not undergo purification process. It also contains excess methanol, catalyst and soap. Conventionally, purification method of the crude glycerol involves high cost and complex processes. This study aimed to determine the effects of using different purification methods which are direct method (comprises of ion exchange and methanol removal steps) and multistep method (comprises of neutralization, filtration, ion exchange and methanol removal steps). Two crude glycerol samples were investigated; the self-produced sample through the transesterification process of palm oil and the sample obtained from biodiesel plant. Samples were analysed using Fourier Transform Infrared Spectroscopy, Gas Chromatography and High Performance Liquid Chromatography. The results of this study for both samples after purification have showed that the pure glycerol was successfully produced and fatty acid salts were eliminated. Also, the results indicated the absence of methanol in both samples after purification process. In short, the combination of 4 purification steps has contributed to a higher quality of glycerol. Multistep purification method gave a better result compared to the direct method as neutralization and filtration steps helped in removing most excess salt, fatty acid and catalyst.

  18. Protection and systemic translocation of siRNA following oral administration of chitosan/siRNA nanoparticles

    DEFF Research Database (Denmark)

    Gonzalez, Borja Ballarin; Dagnæs-Hansen, Frederik; Fenton, Robert A.

    2013-01-01

    , gastrointestinal (GI) deposition, and translocation into peripheral tissue of nonmodified siRNA after oral gavage of chitosan/siRNA nanoparticles in mice. In contrast to naked siRNA, retained structural integrity and deposition in the stomach, proximal and distal small intestine, and colon was observed at 1 and 5...... hours for siRNA within nanoparticles. Furthermore, histological detection of fluorescent siRNA at the apical regions of the intestinal epithelium suggests mucoadhesion provided by chitosan. Detection of intact siRNA in the liver, spleen, and kidney was observed 1 hour after oral gavage, with an organ...

  19. Purification of industrial effluents with a high load of organic pollutants by a combined anaerobic/aerobic process; Reinigung organisch hochbelasteter Industriebwaesser durch eine anaerob/aerobe Verfahrenskombination

    Energy Technology Data Exchange (ETDEWEB)

    Reidl, H.H. [AEW ESMIL GmbH fuer Wasser- und Abwassersyteme, Ratingen (Germany)

    1994-12-31

    Organically polluted sewage water can be economically cleaned in an aerobic biological sewage treatment plant with upstream anaerobic as this saves activation volume and ventilation energy. This was demonstrated in the sewage treatment plant of the PWA in Redenfelden, where an anaerobic stage was installed which uses the BIOTHANE{sup R} process. The CARROUSEL-system of the anaerobic stage has proved a istself both in the PWA ans in municipal plants between 5000 to 100000 EW. It is a robust system with uncomplicated control which guarantees observance of maximum values and allows elimation of P and N. (orig.) [Deutsch] Organisch hochbelastete Abwaesser werden oekonomisch durch eine aerobe biologische Klaeranlage mit vorgeschalteter Anaerobie gereinigt, weil dadurch Belebungsvolumen und Belueftungsenergie eingespart werden. Dies wurde am Beispiel der Abwasserreinigungsanlage der PWA Redenfelden gezeigt, bie der eine Anaerobstufe nach den BIOTHANE{sup R}-Verfahren installiert ist. Das dort eingesetzte CARROUSEL-System fuer die Aerobstufe hat sich sowohl bei der PWA als auch im kommunalen Bereich bei Anlagen zwischen 5000 und 100000 EW, als robustes System mit unkomplizierter Steuerung bewaehrt, das eine sichere Einhaltung der Grenzwerte garantiert und die Moeglichkeit zur P- und N-Elimination bietet. (orig.)

  20. Purification and characterization of endo-beta-1,4 mannanase from Aspergillus niger gr for application in food processing industry.

    Science.gov (United States)

    Naganagouda, K; Salimath, P V; Mulimani, V H

    2009-10-01

    A thermostable extracellular beta-mannanase from the culture supernatant of a fungus Aspergillus niger gr was purified to homogeneity. SDS-PAGE of the purified enzyme showed a single protein band of molecular mass 66 kDa. The beta- mannanase exhibited optimum catalytic activity at pH 5.5 and 55 degrees C. It was thermostable at 55 degrees C, and retained 50% activity after 6 h at 55 degrees C. The enzyme was stable at a pH range of 3.0 to 7.0. The metal ions Hg(2+), Cu(2+), and Ag(2+) inhibited complete enzyme activity. The inhibitors tested, EDTA, PMSF, and 1,10-phenanthroline, did not inhibit the enzyme activity. N-Bromosuccinimide completely inhibited enzyme activity. The relative substrate specificity of enzyme towards the various mannans is in the order of locust bean gum>guar gum>copra mannan, with K(m) of 0.11, 0.28, and 0.33 mg/ml, respectively. Since the enzyme is active over a wide range of pH and temperature, it could find potential use in the food-processing industry.

  1. Strep-Tagged Protein Purification.

    Science.gov (United States)

    Maertens, Barbara; Spriestersbach, Anne; Kubicek, Jan; Schäfer, Frank

    2015-01-01

    The Strep-tag system can be used to purify recombinant proteins from any expression system. Here, protocols for lysis and affinity purification of Strep-tagged proteins from E. coli, baculovirus-infected insect cells, and transfected mammalian cells are given. Depending on the amount of Strep-tagged protein in the lysate, a protocol for batch binding and subsequent washing and eluting by gravity flow can be used. Agarose-based matrices with the coupled Strep-Tactin ligand are the resins of choice, with a binding capacity of up to 9 mg ml(-1). For purification of lower amounts of Strep-tagged proteins, the use of Strep-Tactin magnetic beads is suitable. In addition, Strep-tagged protein purification can also be automated using prepacked columns for FPLC or other liquid-handling chromatography instrumentation, but automated purification is not discussed in this protocol. The protocols described here can be regarded as an update of the Strep-Tag Protein Handbook (Qiagen, 2009). © 2015 Elsevier Inc. All rights reserved.

  2. Generation, concentration and purification for ionic entangled states

    International Nuclear Information System (INIS)

    Yang Ming; Cao Zhuoliang

    2007-01-01

    In cavity QED, the atoms would be sent through the sequential arrays of cavities for the generation of multi-cavity entanglement, or several atoms would be sent into the same cavity mode one bye one for the generation of multi-atom entanglement. The complexity of these processes will impose limitations on the experimental feasibility of it. So, following our previous publication [International Journal Of Quantum Information 2, 231 (2004)] we will propose an alternative scheme for the preparation of multi-cavity W state via cavity QED, which uses the geometrical method to do what other authors have proposed previously using sequential arrays of cavities. Due to the impossibility that one quantum system can be isolated from the environment absolutely, the entanglement of the entangled objects will decrease exponentially with the propagating distance of the objects, and the practically available quantum entangled states are all non-maximally entangled states or the more general case--mixed states. Following our previous publications [Phys. Rev. A 72, 042307 (2005), ibid. 71, 012308 (2005)], we will propose an entanglement generation, concentration and purification scheme for atomic or ionic system, which is mainly based on Cavity QED and linear optical elements. This purification process avoids the controlled-NOT (C-NOT) operations needed in the original purification protocol, which simplifies the whole purification process

  3. High-throughput screening of effective siRNAs using luciferase-linked chimeric mRNA.

    Directory of Open Access Journals (Sweden)

    Shen Pang

    Full Text Available The use of siRNAs to knock down gene expression can potentially be an approach to treat various diseases. To avoid siRNA toxicity the less transcriptionally active H1 pol III promoter, rather than the U6 promoter, was proposed for siRNA expression. To identify highly efficacious siRNA sequences, extensive screening is required, since current computer programs may not render ideal results. Here, we used CCR5 gene silencing as a model to investigate a rapid and efficient screening approach. We constructed a chimeric luciferase-CCR5 gene for high-throughput screening of siRNA libraries. After screening approximately 900 shRNA clones, 12 siRNA sequences were identified. Sequence analysis demonstrated that most (11 of the 12 sequences of these siRNAs did not match those identified by available siRNA prediction algorithms. Significant inhibition of CCR5 in a T-lymphocyte cell line and primary T cells by these identified siRNAs was confirmed using the siRNA lentiviral vectors to infect these cells. The inhibition of CCR5 expression significantly protected cells from R5 HIV-1JRCSF infection. These results indicated that the high-throughput screening method allows efficient identification of siRNA sequences to inhibit the target genes at low levels of expression.

  4. Nanocapsule-mediated cytosolic siRNA delivery for anti-inflammatory treatment.

    Science.gov (United States)

    Jiang, Ying; Hardie, Joseph; Liu, Yuanchang; Ray, Moumita; Luo, Xiang; Das, Riddha; Landis, Ryan F; Farkas, Michelle E; Rotello, Vincent M

    2018-06-05

    The use of nanoparticle-stabilized nanocapsules for cytosolic siRNA delivery for immunomodulation in vitro and in vivo is reported. These NPSCs deliver siRNA directly to the cytosol of macrophages in vitro with concomitant knockdown of gene expression. In vivo studies showed directed delivery of NPSCs to the spleen, enabling gene silencing of macrophages, with preliminary studies showing 70% gene knockdown at a siRNA dose of 0.28 mg/kg. Significantly, the delivery of siRNA targeting tumor necrosis factor-α efficiently silenced TNF-α expression in LPS-challenged mice, demonstrating efficacy in modulating immune response in an organ-selective manner. This research highlights the potential of the NPSC platform for targeted immunotherapy and further manipulation of the immune system. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Low cytotoxicity fluorescent PAMAM dendrimer as gene carriers for monitoring the delivery of siRNA

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Lingmei [Sichuan University, State Key Laboratory of Bio-resources and Eco-environment, The Ministry of Education, College of Life Sciences (China); Huang, Saipeng [Chinese Academy of Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Center for Molecular Sciences, Institute of Chemistry (China); Chen, Zhao [Xi’an Jiaotong University, School of Science (China); Li, Yanchao [Chinese Academy of Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Center for Molecular Sciences, Institute of Chemistry (China); Liu, Ke [Sichuan University, State Key Laboratory of Bio-resources and Eco-environment, The Ministry of Education, College of Life Sciences (China); Liu, Yang, E-mail: yliu@iccas.ac.cn; Du, Libo, E-mail: dulibo@iccas.ac.cn [Chinese Academy of Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Center for Molecular Sciences, Institute of Chemistry (China)

    2015-09-15

    Visual detection of gene vectors has attracted a great deal of attention due to the application of these vectors in monitoring and evaluating the effect of gene carriers in living cells. A non-viral vector, the fluorescent PAMAM dendrimer (F-PAMAM), was synthesized through conjugation of PAMAM dendrimers and fluorescein. In vitro and ex vivo experiments show that F-PAMAM exhibits superphotostability, low cytotoxicity and facilitates endocytosis by A549 cells. The vector has a high siRNA binding affinity and it increases the efficiency of cy5-siRNA delivery in A549 cells, in comparison with a cy5-siRNA monomer. Our results provide a new method for simultaneously monitoring the delivery of siRNA and its non-viral carriers in living cells.

  6. siRNA Treatment: “A Sword-in-the-Stone” for Acute Brain Injuries

    Directory of Open Access Journals (Sweden)

    Jerome Badaut

    2013-09-01

    Full Text Available Ever since the discovery of small interfering ribonucleic acid (siRNA a little over a decade ago, it has been highly sought after for its potential as a therapeutic agent for many diseases. In this review, we discuss the promising possibility of siRNA to be used as a drug to treat acute brain injuries such as stroke and traumatic brain injury. First, we will give a brief and basic overview of the principle of RNA interference as an effective mechanism to decrease specific protein expression. Then, we will review recent in vivo studies describing siRNA research experiments/treatment options for acute brain diseases. Lastly, we will discuss the future of siRNA as a clinical therapeutic strategy against brain diseases and injuries, while addressing the current obstacles to effective brain delivery.

  7. Smart Inulin-Based Polycationic Nanodevices for siRNA Delivery.

    Science.gov (United States)

    Cavallaro, G; Sardo, C; Scialabba, C; Licciardi, M; Giammona, G

    2017-01-01

    The advances of short interfering RNA (siRNA) mediated therapy provide a powerful option for the treatment of many diseases by silencing the expression of targeted genes including cancer development and progression. Inulin is a very simple and biocompatible polysaccharide proposed by our groups to produce interesting delivery systems for Nucleic Acid Based Drugs (NABDs), such as siRNA, either as polycations able to give polyplexes and polymeric coatings for nanosystems having a metallic core. In this research field, different functionalizing groups were linked to the inulin backbone with specific aims including oligoamine such as Ethylendiammine (EDA), Diethylediamine (DETA), Spermine, (SPM) etc. In this contribution the main Inulin-based nanodevices for the delivery of siRNA have been reported, analysed and compared with particular reference to their chemical design and structure, biocompatibility, siRNA complexing ability, silencing ability. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  8. Development of an innovative process for sustainable purification of effluents, especially in countries with high insolation. Final report; Entwicklung eines innovativen Verfahrens zur nachhaltigen Abwasserreinigung, besonders in Laendern mit hoher Sonneneinstrahlung. Endbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    General globalisation and increasing orientation of exporting branches of environmental technology towards the so called developing countries or threshold countries require new technological approaches which facilitate sustainable management in those countries especially with waste and sewage treatment. In order to protect ground and surface waters and to reduce ecological damages / nutrient discharge there is an urgent demand to remove not only oxygen consuming organic carbon compounds, but for example also ammonia-nitrogen, nitrate-nitrogen and phosphorus from wastewater in order to prevent further eutrophication of the waters. However it is known that this results in a high technological and financial expenditure. The algae reactor developed in the research project makes use of the synergetic effect of heterotrophic and photoauto-/-heterotrophic organisms immobilized on an inert carrier material as biofilm, in order to achieve a purification efficiency that could so far only be reached with costly procedural solutions. The auto- and heterotrophic microalgae and cyanobacteria established in the biofilm contributed to the COD-decomposition and the oxygen supply for the heterotrophic bacteria in the biofilm. This synergetic effect enabled a COD-decomposition of up to 94%. The developed and tested process allowed for an extensive nitrogen decomposition of up to 80%. The phosphorus reduction correlated with the content of green algae in the biofilm and amounted up to 40%. The excess biomass formed during the process could be anaerobically converted into biogas at high methane contents (up to 74%). Alternatively, the excess biomass could also be utilized as NPK-fertilizer. A first calculation of profitability showed that the compact design and the fact that a technical ventilation of the algae reactor is not necessary because of the oxygen supply for the heterotrophic bacteria by microalgae and cyanobacteria resulted in extensive economies for investment costs and

  9. Solid nano-in-nanoparticles for potential delivery of siRNA.

    Science.gov (United States)

    Amsalem, Orit; Nassar, Taher; Benhamron, Sandrine; Lazarovici, Philip; Benita, Simon; Yavin, Eylon

    2017-07-10

    siRNA-based therapeutics possess great potential to treat a wide variety of genetic disorders. However, they suffer from low cellular uptake and short half-lives in blood circulation; issues that remain to be addressed. This work is, to the best of our knowledge, the first to report the production of solid nano-in-nanoparticles, termed double nano carriers (DNCs) by means of the innovative technology of nano spray drying. DNCs (with a median size of 580-770nm) were produced by spraying at low temperatures (50°C) to prevent damage to heat-sensitive biomacromolecules like siRNA. DNCs consisting of Poly (d,l-lactide-co-glycolide) used as a wall material, encapsulating 20% human serum albumin primary nanoparticles (PNPs) loaded with siRNA, were obtained as a dry nanoparticulate powder with smooth spherical surfaces and a unique inner morphology. Incubation of pegylated or non-pegylated DNCs under sink conditions at 37°C, elicited a controlled release profile of the siRNA for up to 12 or 24h, respectively, with a minimal burst effect. Prolonged incubation of pegylated DNCs loaded with active siRNA (anti EGFR) in an A549 epithelial cell culture monolayer did not induce any apparent cytotoxicity. A slow degradation of the internalized DNCs by the cells was also observed resulting in the progressive release of the siRNA for up to 6days, as corroborated by laser confocal microscopy. The structural integrity and silencing activity of the double encapsulated siRNA were fully preserved, as demonstrated by HPLC, gel electrophoresis, and potent RNAi activity of siRNA extracted from DNCs. These results demonstrate the potential use of DNCs as a nano drug delivery system for systemic administration and controlled release of siRNA and potentially other sensitive bioactive macromolecules. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. [Efficacy of siRNA on feline leukemia virus replication in vitro].

    Science.gov (United States)

    Lehmann, Melanie; Weber, Karin; Rauch, Gisep; Hofmann-Lehmann, Regina; Hosie, Margaret J; Meli, Marina L; Hartmann, Katrin

    2015-01-01

    Feline leukemia virus (FeLV) can lead to severe clinical signs in cats. Until now, there is no effective therapy for FeLV-infected cats. RNA interference-based antiviral therapy is a new concept. Specific small interfering RNA (siRNA) are designed complementary to the mRNA of a target region, and thus inhibit replication. Several studies have proven efficacy of siRNAs in inhibiting virus replication. The aim of this study was to evaluate the inhibitory potential of siRNAs against FeLV replication in vitro. siRNAs against the FeLV env gene and the host cell surface receptor (feTHTR1) which is used by FeLV-A for entry as well as siRNA that were not complementary to the FeLV or cat genome, were tested. Crandell feline kidney cells (CrFK cells) were transfected with FeLV-A/Glasgow-1. On day 13, infected cells were transfected with siRNAs. As control, cells were mock-transfected or treated with azidothymidine (AZT) (5 μg/ml). Culture supernatants were analyzed for FeLV RNA using quantitative real-time RT-PCR and for FeLV p27 by ELISA every 24 hours for five days. All siRNAs significantly reduced viral RNA and p27 production, starting after 48 hours. The fact that non-complementary siRNAs also inhibited virus replication may lead to the conclusion that unspecific mechanisms rather than specific binding lead to inhibition.

  11. Enhancing potency of siRNA targeting fusion genes by optimization outside of target sequence.

    Science.gov (United States)

    Gavrilov, Kseniya; Seo, Young-Eun; Tietjen, Gregory T; Cui, Jiajia; Cheng, Christopher J; Saltzman, W Mark

    2015-12-01

    Canonical siRNA design algorithms have become remarkably effective at predicting favorable binding regions within a target mRNA, but in some cases (e.g., a fusion junction site) region choice is restricted. In these instances, alternative approaches are necessary to obtain a highly potent silencing molecule. Here we focus on strategies for rational optimization of two siRNAs that target the junction sites of fusion oncogenes BCR-ABL and TMPRSS2-ERG. We demonstrate that modifying the termini of these siRNAs with a terminal G-U wobble pair or a carefully selected pair of terminal asymmetry-enhancing mismatches can result in an increase in potency at low doses. Importantly, we observed that improvements in silencing at the mRNA level do not necessarily translate to reductions in protein level and/or cell death. Decline in protein level is also heavily influenced by targeted protein half-life, and delivery vehicle toxicity can confound measures of cell death due to silencing. Therefore, for BCR-ABL, which has a long protein half-life that is difficult to overcome using siRNA, we also developed a nontoxic transfection vector: poly(lactic-coglycolic acid) nanoparticles that release siRNA over many days. We show that this system can achieve effective killing of leukemic cells. These findings provide insights into the implications of siRNA sequence for potency and suggest strategies for the design of more effective therapeutic siRNA molecules. Furthermore, this work points to the importance of integrating studies of siRNA design and delivery, while heeding and addressing potential limitations such as restricted targetable mRNA regions, long protein half-lives, and nonspecific toxicities.

  12. Rev1, Rev3, or Rev7 siRNA Abolishes Ultraviolet Light-Induced Translesion Replication in HeLa Cells: A Comprehensive Study Using Alkaline Sucrose Density Gradient Sedimentation

    Directory of Open Access Journals (Sweden)

    Jun Takezawa

    2010-01-01

    Full Text Available When a replicative DNA polymerase stalls upon encountering a lesion on the template strand, it is relieved by other low-processivity polymerase(s, which insert nucleotide(s opposite the lesion, extend by a few nucleotides, and dissociate from the 3′-OH. The replicative polymerase then resumes DNA synthesis. This process, termed translesion replication (TLS or replicative bypass, may involve at least five different polymerases in mammals, although the participating polymerases and their roles have not been entirely characterized. Using siRNAs originally designed and an alkaline sucrose density gradient sedimentation technique, we verified the involvement of several polymerases in ultraviolet (UV light-induced TLS in HeLa cells. First, siRNAs to Rev3 or Rev7 largely abolished UV-TLS, suggesting that these 2 gene products, which comprise Polζ, play a main role in mutagenic TLS. Second, Rev1-targeted siRNA also abrogated UV-TLS, indicating that Rev1 is also indispensable to mutagenic TLS. Third, Polη-targeted siRNA also prevented TLS to a greater extent than our expectations. Forth, although siRNA to Polι had no detectable effect, that to Polκ delayed UV-TLS. To our knowledge, this is the first study reporting apparent evidence for the participation of Polκ in UV-TLS.

  13. [siRNAs with high specificity to the target: a systematic design by CRM algorithm].

    Science.gov (United States)

    Alsheddi, T; Vasin, L; Meduri, R; Randhawa, M; Glazko, G; Baranova, A

    2008-01-01

    'Off-target' silencing effect hinders the development of siRNA-based therapeutic and research applications. Common solution to this problem is an employment of the BLAST that may miss significant alignments or an exhaustive Smith-Waterman algorithm that is very time-consuming. We have developed a Comprehensive Redundancy Minimizer (CRM) approach for mapping all unique sequences ("targets") 9-to-15 nt in size within large sets of sequences (e.g. transcriptomes). CRM outputs a list of potential siRNA candidates for every transcript of the particular species. These candidates could be further analyzed by traditional "set-of-rules" types of siRNA designing tools. For human, 91% of transcripts are covered by candidate siRNAs with kernel targets of N = 15. We tested our approach on the collection of previously described experimentally assessed siRNAs and found that the correlation between efficacy and presence in CRM-approved set is significant (r = 0.215, p-value = 0.0001). An interactive database that contains a precompiled set of all human siRNA candidates with minimized redundancy is available at http://129.174.194.243. Application of the CRM-based filtering minimizes potential "off-target" silencing effects and could improve routine siRNA applications.

  14. In vivo therapeutic potential of Dicer-hunting siRNAs targeting infectious hepatitis C virus.

    Science.gov (United States)

    Watanabe, Tsunamasa; Hatakeyama, Hiroto; Matsuda-Yasui, Chiho; Sato, Yusuke; Sudoh, Masayuki; Takagi, Asako; Hirata, Yuichi; Ohtsuki, Takahiro; Arai, Masaaki; Inoue, Kazuaki; Harashima, Hideyoshi; Kohara, Michinori

    2014-04-23

    The development of RNA interference (RNAi)-based therapy faces two major obstacles: selecting small interfering RNA (siRNA) sequences with strong activity, and identifying a carrier that allows efficient delivery to target organs. Additionally, conservative region at nucleotide level must be targeted for RNAi in applying to virus because hepatitis C virus (HCV) could escape from therapeutic pressure with genome mutations. In vitro preparation of Dicer-generated siRNAs targeting a conserved, highly ordered HCV 5' untranslated region are capable of inducing strong RNAi activity. By dissecting the 5'-end of an RNAi-mediated cleavage site in the HCV genome, we identified potent siRNA sequences, which we designate as Dicer-hunting siRNAs (dh-siRNAs). Furthermore, formulation of the dh-siRNAs in an optimized multifunctional envelope-type nano device inhibited ongoing infectious HCV replication in human hepatocytes in vivo. Our efforts using both identification of optimal siRNA sequences and delivery to human hepatocytes suggest therapeutic potential of siRNA for a virus.

  15. Lipid-Based Liquid Crystalline Nanoparticles Facilitate Cytosolic Delivery of siRNA via Structural Transformation.

    Science.gov (United States)

    He, Shufang; Fan, Weiwei; Wu, Na; Zhu, Jingjing; Miao, Yunqiu; Miao, Xiaran; Li, Feifei; Zhang, Xinxin; Gan, Yong

    2018-04-11

    RNA interference (RNAi) technology has shown great promise for the treatment of cancer and other genetic disorders. Despite the efforts to increase the target tissue distribution, the safe and effective delivery of siRNA to the diseased cells with sufficient cytosolic transport is another critical factor for successful RNAi clinical application. Here, the constructed lipid-based liquid crystalline nanoparticles, called nano-Transformers, can transform thestructure in the intracellular acidic environment and perform high-efficient siRNA delivery for cancer treatment. The developed nano-Transformers have satisfactory siRNA loading efficiency and low cytotoxicity. Different from the traditional cationic nanocarriers, the endosomal membrane fusion induced by the conformational transition of lipids contributes to the easy dissociation of siRNA from nanocarriers and direct release of free siRNA into cytoplasm. We show that transfection with cyclin-dependent kinase 1 (CDK1)-siRNA-loaded nano-Transformers causes up to 95% reduction of relevant mRNA in vitro and greatly inhibits the tumor growth without causing any immunogenic response in vivo. This work highlights that the lipid-based nano-Transformers may become the next generation of siRNA delivery system with higher efficacy and improved safety profiles.

  16. Nanosystems based on siRNA silencing HuR expression counteract diabetic retinopathy in rat.

    Science.gov (United States)

    Amadio, Marialaura; Pascale, Alessia; Cupri, Sarha; Pignatello, Rosario; Osera, Cecilia; D Agata, Velia; D Amico, Agata Grazia; Leggio, Gian Marco; Ruozi, Barbara; Govoni, Stefano; Drago, Filippo; Bucolo, Claudio

    2016-09-01

    We evaluated whether specifically and directly targeting human antigen R (HuR), a member of embryonic lethal abnormal vision (ELAV) proteins family, may represent a new potential therapeutic strategy to manage diabetic retinopathy. Nanosystems loaded with siRNA silencing HuR expression (lipoplexes), consisting of solid lipid nanoparticles (SLN) and liposomes (SUV) were prepared. Photon correlation spectroscopy analysis, Zeta potential measurement and atomic force microscopy (AFM) studies were carried out to characterize the complexation of siRNA with the lipid nanocarriers. Nanosystems were evaluated by using AFM and scanning electron microscopy. The lipoplexes were injected into the eye of streptozotocin (STZ)-induced diabetic rats. Retinal HuR and VEGF levels were detected by Western blot and ELISA, respectively. Retinal histology was also carried out. The results demonstrated that retinal HuR and VEGF are significantly increased in STZ-rats and are blunted by HuR siRNA treatment. Lipoplexes with a weak positive surface charge and with a 4:1 N/P (cationic lipid nitrogen to siRNA phosphate) ratio exert a better transfection efficiency, significantly dumping retinal HuR and VEGF levels. In conclusion, we demonstrated that siRNA can be efficiently delivered into the rat retina using lipid-based nanocarriers, and some of the lipoplexes loaded with siRNA silencing HuR expression are potential candidates to manage retinal diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Mapping Optimal Charge Density and Length of ROMP-Based PTDMs for siRNA Internalization.

    Science.gov (United States)

    Caffrey, Leah M; deRonde, Brittany M; Minter, Lisa M; Tew, Gregory N

    2016-10-10

    A fundamental understanding of how polymer structure impacts internalization and delivery of biologically relevant cargoes, particularly small interfering ribonucleic acid (siRNA), is of critical importance to the successful design of improved delivery reagents. Herein we report the use of ring-opening metathesis polymerization (ROMP) methods to synthesize two series of guanidinium-rich protein transduction domain mimics (PTDMs): one based on an imide scaffold that contains one guanidinium moiety per repeat unit, and another based on a diester scaffold that contains two guanidinium moieties per repeat unit. By varying both the degree of polymerization and, in effect, the relative number of cationic charges in each PTDM, the performances of the two ROMP backbones for siRNA internalization were evaluated and compared. Internalization of fluorescently labeled siRNA into Jurkat T cells demonstrated that fluorescein isothiocyanate (FITC)-siRNA internalization had a charge content dependence, with PTDMs containing approximately 40 to 60 cationic charges facilitating the most internalization. Despite this charge content dependence, the imide scaffold yielded much lower viabilities in Jurkat T cells than the corresponding diester PTDMs with similar numbers of cationic charges, suggesting that the diester scaffold is preferred for siRNA internalization and delivery applications. These developments will not only improve our understanding of the structural factors necessary for optimal siRNA internalization, but will also guide the future development of optimized PTDMs for siRNA internalization and delivery.

  18. Low molecular weight chitosan conjugated with folate for siRNA delivery in vitro: optimization studies

    Science.gov (United States)

    Fernandes, Julio C; Qiu, Xingping; Winnik, Francoise M; Benderdour, Mohamed; Zhang, Xiaoling; Dai, Kerong; Shi, Qin

    2012-01-01

    The low transfection efficiency of chitosan is one of its drawbacks as a gene delivery carrier. Low molecular weight chitosan may help to form small-sized polymer-DNA or small interfering RNA (siRNA) complexes. Folate conjugation may improve gene transfection efficiency because of the promoted uptake of folate receptor-bearing cells. In the present study, chitosan was conjugated with folate and investigated for its efficacy as a delivery vector for siRNA in vitro. We demonstrate that the molecular weight of chitosan has a major influence on its biological and physicochemical properties, and very low molecular weight chitosan (below 10 kDa) has difficulty in forming stable complexes with siRNA. In this study, chitosan 25 kDa and 50 kDa completely absorbed siRNA and formed nanoparticles (≤220 nm) at a chitosan to siRNA weight ratio of 50:1. The introduction of a folate ligand onto chitosan decreased nanoparticle toxicity. Compared with chitosan-siRNA, folate-chitosan-siRNA nanoparticles improved gene silencing transfection efficiency. Therefore, folate-chitosan shows potential as a viable candidate vector for safe and efficient siRNA delivery. PMID:23209368

  19. Electrochemical Processes

    DEFF Research Database (Denmark)

    Bech-Nielsen, Gregers

    1997-01-01

    The notes describe in detail primary and secondary galvanic cells, fuel cells, electrochemical synthesis and electroplating processes, corrosion: measurments, inhibitors, cathodic and anodic protection, details of metal dissolution reactions, Pourbaix diagrams and purification of waste water from...

  20. High quality protein microarray using in situ protein purification

    Directory of Open Access Journals (Sweden)

    Fleischmann Robert D

    2009-08-01

    Full Text Available Abstract Background In the postgenomic era, high throughput protein expression and protein microarray technologies have progressed markedly permitting screening of therapeutic reagents and discovery of novel protein functions. Hexa-histidine is one of the most commonly used fusion tags for protein expression due to its small size and convenient purification via immobilized metal ion affinity chromatography (IMAC. This purification process has been adapted to the protein microarray format, but the quality of in situ His-tagged protein purification on slides has not been systematically evaluated. We established methods to determine the level of purification of such proteins on metal chelate-modified slide surfaces. Optimized in situ purification of His-tagged recombinant proteins has the potential to become the new gold standard for cost-effective generation of high-quality and high-density protein microarrays. Results Two slide surfaces were examined, chelated Cu2+ slides suspended on a polyethylene glycol (PEG coating and chelated Ni2+ slides immobilized on a support without PEG coating. Using PEG-coated chelated Cu2+ slides, consistently higher purities of recombinant proteins were measured. An optimized wash buffer (PBST composed of 10 mM phosphate buffer, 2.7 mM KCl, 140 mM NaCl and 0.05% Tween 20, pH 7.4, further improved protein purity levels. Using Escherichia coli cell lysates expressing 90 recombinant Streptococcus pneumoniae proteins, 73 proteins were successfully immobilized, and 66 proteins were in situ purified with greater than 90% purity. We identified several antigens among the in situ-purified proteins via assays with anti-S. pneumoniae rabbit antibodies and a human patient antiserum, as a demonstration project of large scale microarray-based immunoproteomics profiling. The methodology is compatible with higher throughput formats of in vivo protein expression, eliminates the need for resin-based purification and circumvents

  1. Advanced purification of petroleum refinery wastewater by catalytic vacuum distillation.

    Science.gov (United States)

    Yan, Long; Ma, Hongzhu; Wang, Bo; Mao, Wei; Chen, Yashao

    2010-06-15

    In our work, a new process, catalytic vacuum distillation (CVD) was utilized for purification of petroleum refinery wastewater that was characteristic of high chemical oxygen demand (COD) and salinity. Moreover, various common promoters, like FeCl(3), kaolin, H(2)SO(4) and NaOH were investigated to improve the purification efficiency of CVD. Here, the purification efficiency was estimated by COD testing, electrolytic conductivity, UV-vis spectrum, gas chromatography-mass spectrometry (GC-MS) and pH value. The results showed that NaOH promoted CVD displayed higher efficiency in purification of refinery wastewater than other systems, where the pellucid effluents with low salinity and high COD removal efficiency (99%) were obtained after treatment, and the corresponding pH values of effluents varied from 7 to 9. Furthermore, environment estimation was also tested and the results showed that the effluent had no influence on plant growth. Thus, based on satisfied removal efficiency of COD and salinity achieved simultaneously, NaOH promoted CVD process is an effective approach to purify petroleum refinery wastewater. Copyright 2010 Elsevier B.V. All rights reserved.

  2. Sodium purification in Rapsodie; La purification du sodium a Rapsodie

    Energy Technology Data Exchange (ETDEWEB)

    Giraud, B [Commissariat a l' Energie Atomique, Dir. des Piles Atomiques, Cadarache (France). Centre d' Etudes Nucleaires

    1968-07-01

    This report is one of a series of publications presenting the main results of tests carried out during the start-up of the first french fast neutron reactor: Rapsodie. The article presents the sodium purification techniques used in the reactor cooling circuits both from the constructional point of view and with respect to results obtained during the first years working. (author) [French] Ce rapport fait partie d'une serie de publications presentant l'essentiel des resultats des essais effectues a l'occasion du demarrage du premier reacteur francais a neutrons rapides: RAPSODIE. Cet article expose les techniques de la purification du sodium utilise dans les circuits de refroidissement du reacteur tant au point de vue de leur realisation technologique, que des resultats obtenus pendant la premiere annee de fonctionnement. (auteur)

  3. Water purification using solar radiation in Nigeria

    International Nuclear Information System (INIS)

    Udounwa, A.E.; Osuji, R.U.

    2005-12-01

    In developing countries, lack of safe and reliable drinking water constitutes a major problem. Contaminated water is the major cause of most water borne diseases like diarrhoea. Disinfection of water is accomplished by a number of different physical - chemical treatments including boiling, application of chlorine and filtration techniques. Solar energy, which is universally available, can also be used effectively in this process, that is, to deactivate the micro-organisms present in this contaminated water thereby improving its microbiological quality. This treatment process is called solar water disinfection. This paper therefore appraises the extent to which research work has been done as regards purification of water using solar radiation in Nigeria vis-a-vis outside the country. It is hoped that it will serve as a wake-up-call for Nigerians especially those in remote areas with no treated pipe borne water supply. The problems and prospects of this technology as well as the policy implications are presented. (author)

  4. Nanocellulose-Based Materials for Water Purification.

    Science.gov (United States)

    Voisin, Hugo; Bergström, Lennart; Liu, Peng; Mathew, Aji P

    2017-03-05

    Nanocellulose is a renewable material that combines a high surface area with high strength, chemical inertness, and versatile surface chemistry. In this review, we will briefly describe how nanocellulose is produced, and present-in particular, how nanocellulose and its surface modified versions affects the adsorption behavior of important water pollutants, e.g., heavy metal species, dyes, microbes, and organic molecules. The processing of nanocellulose-based membranes and filters for water purification will be described in detail, and the uptake capacity, selectivity, and removal efficiency will also be discussed. The processing and performance of nanocellulose-based membranes, which combine a high removal efficiency with anti-fouling properties, will be highlighted.

  5. Nanocellulose-Based Materials for Water Purification

    Directory of Open Access Journals (Sweden)

    Hugo Voisin

    2017-03-01

    Full Text Available Nanocellulose is a renewable material that combines a high surface area with high strength, chemical inertness, and versatile surface chemistry. In this review, we will briefly describe how nanocellulose is produced, and present—in particular, how nanocellulose and its surface modified versions affects the adsorption behavior of important water pollutants, e.g., heavy metal species, dyes, microbes, and organic molecules. The processing of nanocellulose-based membranes and filters for water purification will be described in detail, and the uptake capacity, selectivity, and removal efficiency will also be discussed. The processing and performance of nanocellulose-based membranes, which combine a high removal efficiency with anti-fouling properties, will be highlighted.

  6. INVESTIGATIONS ON BIOCHEMICAL PURIFICATION OF GROUND WATER FROM HYDROGEN SULFIDE

    Directory of Open Access Journals (Sweden)

    Yu. P. Sedlukho

    2015-01-01

    Full Text Available The paper considers problems and features of biochemical removal of hydrogen sulfide from ground water. The analysis of existing methods for purification of ground water from hydrogen sulfide has been given in the paper. The paper has established shortcomings of physical and chemical purification of ground water. While using aeration methods for removal of hydrogen sulfide formation of colloidal sulfur that gives muddiness and opalescence to water occurs due to partial chemical air oxidation. In addition to this violation of sulfide-carbonate equilibrium taking place in the process of aeration due to desorption of H2S and CO2, often leads to clogging of degasifier nozzles with formed CaCO3 that causes serious operational problems. Chemical methods require relatively large flow of complex reagent facilities, storage facilities and transportation costs.In terms of hydrogen sulfide ground water purification the greatest interest is given to the biochemical method. Factors deterring widespread application of the biochemical method is its insufficient previous investigation and necessity to execute special research in order to determine optimal process parameters while purifying groundwater of a particular water supply source. Biochemical methods for oxidation of sulfur compounds are based on natural biological processes that ensure natural sulfur cycle. S. Vinogradsky has established a two-stage mechanism for oxidation of hydrogen sulfide with sulfur bacteria (Beggiatoa. The first stage presupposes oxidation of hydrogen sulphide to elemental sulfur which is accumulating in the cytoplasm in the form of globules. During the second stage sulfur bacteria begin to oxidize intracellular sulfur to sulfuric acid due to shortage of hydrogen sulfide.The paper provides the results of technological tests of large-scale pilot plants for biochemical purification of groundwater from hydrogen sulfide in semi-industrial conditions. Dependences of water quality

  7. BSA Nanoparticles for siRNA Delivery: Coating Effects on Nanoparticle Properties, Plasma Protein Adsorption, and In Vitro siRNA Delivery

    Directory of Open Access Journals (Sweden)

    Haran Yogasundaram

    2012-01-01

    Full Text Available Developing vehicles for the delivery of therapeutic molecules, like siRNA, is an area of active research. Nanoparticles composed of bovine serum albumin, stabilized via the adsorption of poly-L-lysine (PLL, have been shown to be potentially inert drug-delivery vehicles. With the primary goal of reducing nonspecific protein adsorption, the effect of using comb-type structures of poly(ethylene glycol (1 kDa, PEG units conjugated to PLL (4.2 and 24 kDa on BSA-NP properties, apparent siRNA release rate, cell viability, and cell uptake were evaluated. PEGylated PLL coatings resulted in NPs with ζ-potentials close to neutral. Incubation with platelet-poor plasma showed the composition of the adsorbed proteome was similar for all systems. siRNA was effectively encapsulated and released in a sustained manner from all NPs. With 4.2 kDa PLL, cellular uptake was not affected by the presence of PEG, but PEG coating inhibited uptake with 24 kDa PLL NPs. Moreover, 24 kDa PLL systems were cytotoxic and this cytotoxicity was diminished upon PEG incorporation. The overall results identified a BSA-NP coating structure that provided effective siRNA encapsulation while reducing ζ-potential, protein adsorption, and cytotoxicity, necessary attributes for in vivo application of drug-delivery vehicles.

  8. Purification of hydrogen sulfide

    International Nuclear Information System (INIS)

    Tsao, U.

    1978-01-01

    A process is described for purifying a hydrogen sulfide gas stream containing carbon dioxide, comprising (a) passing the gas stream through a bed of solid hydrated lime to form calcium hydrosulfide and calcium carbonate and (b) regenerating hydrogen sulfide from said calcium hydrosulfide by reacting the calcium hydrosulfide with additional carbon dioxide. The process is especially applicable for use in a heavy water recovery process wherein deuterium is concentrated from a feed water containing carbon dioxide by absorption and stripping using hydrogen sulfide as a circulating medium, and the hydrogen sulfide absorbs a small quantity of carbon dioxide along with deuterium in each circulation

  9. PURIFICATION OF TRANSFORMER OIL in PT. PJB UP PAITON

    OpenAIRE

    Gusti Wahdaniyah*, Purnomo Tri Prasetyo, Arif Setiabudi, Totok R. Biyanto

    2016-01-01

    The purpose of this paper is to describe the filtration or purification of transformer oil. One of the main equipment in coal-fired power generation unit is transformer. When the transformer fail to operate properly, the continuity of distribution system become interrupted. As a part of transformer, transformer oil contribute the failure of transformer due to the aging. To solve this problem, several methods is applied starting from dehydration process, degasification process, oxidation remov...

  10. Water purification using organic salts

    Science.gov (United States)

    Currier, Robert P.

    2004-11-23

    Water purification using organic salts. Feed water is mixed with at least one organic salt at a temperature sufficiently low to form organic salt hydrate crystals and brine. The crystals are separated from the brine, rinsed, and melted to form an aqueous solution of organic salt. Some of the water is removed from the aqueous organic salt solution. The purified water is collected, and the remaining more concentrated aqueous organic salt solution is reused.

  11. Performance of photocatalyst based carbon nanodots from waste frying oil in water purification

    International Nuclear Information System (INIS)

    Aji, Mahardika Prasetya; Wiguna, Pradita Ajeng; Susanto,; Rosita, Nita; Suciningtyas, Siti Aisyah; Sulhadi

    2016-01-01

    Carbon Nanodots (C-Dots) from waste frying oil could be used as a photocatalyst in water purification with solar light irradiation. Performance of C-Dots as a photocatalyst was tested in the process of water purification with a given synthetic sewage methylene blue. The tested was also conducted by comparing the performance C-Dots made from frying oil, waste fryng oil as a photocatalyst and solution of methylene blue without photocatalyst C-Dots. Performance of C-Dots from waste frying oil were estimated by the results of absorbance spectrum. The results of measurement absorbance spectrum from the process of water purification with photocatalyst C-Dots showed that the highest intensity at a wavelength 664 nm of methylene blue decreased. The test results showed that the performance of photocatalyst C-Dots from waste frying oil was better in water purification. This estimated that number of particles C-dots is more in waste frying oil because have experieced repeated the heating process so that the higher particles concentration make the photocatalyst process more effective. The observation of the performance C-Dots from waste frying oil as a photocatalyst in the water purification processes become important invention for solving the problems of waste and water purification.

  12. Performance of photocatalyst based carbon nanodots from waste frying oil in water purification

    Energy Technology Data Exchange (ETDEWEB)

    Aji, Mahardika Prasetya, E-mail: mahardika190@gmail.com; Wiguna, Pradita Ajeng; Susanto,; Rosita, Nita; Suciningtyas, Siti Aisyah; Sulhadi [Department of Physics, Faculty of Mathematics and Natural Science Universitas Negeri Semarang, Jalan Raya Sekaran Gunungpati 50229 Indonesia (Indonesia)

    2016-04-19

    Carbon Nanodots (C-Dots) from waste frying oil could be used as a photocatalyst in water purification with solar light irradiation. Performance of C-Dots as a photocatalyst was tested in the process of water purification with a given synthetic sewage methylene blue. The tested was also conducted by comparing the performance C-Dots made from frying oil, waste fryng oil as a photocatalyst and solution of methylene blue without photocatalyst C-Dots. Performance of C-Dots from waste frying oil were estimated by the results of absorbance spectrum. The results of measurement absorbance spectrum from the process of water purification with photocatalyst C-Dots showed that the highest intensity at a wavelength 664 nm of methylene blue decreased. The test results showed that the performance of photocatalyst C-Dots from waste frying oil was better in water purification. This estimated that number of particles C-dots is more in waste frying oil because have experieced repeated the heating process so that the higher particles concentration make the photocatalyst process more effective. The observation of the performance C-Dots from waste frying oil as a photocatalyst in the water purification processes become important invention for solving the problems of waste and water purification.

  13. Dual-functionalized graphene oxide for enhanced siRNA delivery to breast cancer cells.

    Science.gov (United States)

    Imani, Rana; Shao, Wei; Taherkhani, Samira; Emami, Shahriar Hojjati; Prakash, Satya; Faghihi, Shahab

    2016-11-01

    The aim of this study is to improve hydrocolloid stability and siRNA transfection ability of a reduced graphene oxide (rGO) based nano-carrier using a phospholipid-based amphiphilic polymer (PL-PEG) and cell penetrating peptide (CPPs). The dual functionalized nano-carrier is comprehensively characterized for its chemical structure, size, surface charge and morphology as well as thermal stability. The nano-carrier cytocompatibility, siRNA condensation ability both in the presence and absence of enzyme, endosomal buffering capacity, cellular uptake and intracellular localization are also assessed. The siRNA loaded nano-carrier is used for internalization to MCF-7 cells and its gene silencing ability is compared with AllStars Hs Cell Death siRNA as a model gene. The nano-carrier remains stable in biological solution, exhibits excellent cytocompatibility, retards the siRNA migration and protects it against enzyme degradation. The buffering capacity analysis shows that incorporation of the peptide in nano-carrier structure would increase the resistance to endo/lysosomal like acidic condition (pH 6-4) The functionalized nano-carrier which is loaded with siRNA in an optimal N:P ratio presents superior internalization efficiency (82±5.1% compared to HiPerFect(®)), endosomal escape quality and capable of inducing cell death in MCF-7 cancer cells (51±3.1% compared to non-treated cells). The success of siRNA-based therapy is largely dependent on the safe and efficient delivery system, therefore; the dual functionalized rGO introduced here could have a great potential to be used as a carrier for siRNA delivery with relevancy in therapeutics and clinical applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Thermo-sensitive nanoparticles for triggered release of siRNA.

    Science.gov (United States)

    Yang, Zheng; Cheng, Qiang; Jiang, Qian; Deng, Liandong; Liang, Zicai; Dong, Anjie

    2015-01-01

    Efficient delivery of small interfering RNA (siRNA) is crucially required for cancer gene therapy. Herein, a thermo-sensitive copolymer with a simple structure, poly (ethylene glycol) methyl ether acrylate-b-poly (N-isopropylacrylamide) (mPEG-b-PNIPAM) was developed. A novel kind of thermo-sensitive nanoparticles (DENPs) was constructed for the cold-shock triggered release of siRNA by double emulsion-solvent evaporation method using mPEG-b-PNIPAM and a cationic lipid, 3β [N-(N', N'-dimethylaminoethane)-carbamoyl] cholesterol [DC-Chol]. DENPs were observed by transmission electron microscopy and dynamical light scattering before and after 'cold shock' treatment. The encapsulation efficiency (EE) of siRNA in DENPs, which was measured by fluorescence spectrophotometer was 96.8% while it was significantly reduced to be 23.2% when DC-Chol was absent. DENPs/siRNA NPs exhibited a thermo-sensitive siRNA release character that the cumulatively released amount of siRNA from cold shock was approximately 2.2 folds higher after 7 days. In vitro luciferase silencing experiments indicated that DENPs showed potent gene silencing efficacy in HeLa-Luc cells (HeLa cells steadily expressed luciferase), which was further enhanced by a cold shock. Furthermore, MTT assay showed that cell viability with DENPs/siRNA up to 200 nM remained above 80%. We also observed that most of siRNA was accumulated in kidney mediated by DENPs instead of liver and spleen in vivo experiments. Thus, DENPs as a cold shock responsive quick release model for siRNA or hydrophilic macromolecules delivery provide a new way to nanocarrier design and clinic therapy.

  15. Role of miRNAs and siRNAs in biotic and abiotic stress responses of plants

    KAUST Repository

    Khraiwesh, Basel

    2012-02-01

    Small, non-coding RNAs are a distinct class of regulatory RNAs in plants and animals that control a variety of biological processes. In plants, several classes of small RNAs with specific sizes and dedicated functions have evolved through a series of pathways. The major classes of small RNAs include microRNAs (miRNAs) and small interfering RNAs (siRNAs), which differ in their biogenesis. miRNAs control the expression of cognate target genes by binding to reverse complementary sequences, resulting in cleavage or translational inhibition of the target RNAs. siRNAs have a similar structure, function, and biogenesis as miRNAs but are derived from long double-stranded RNAs and can often direct DNA methylation at target sequences. Besides their roles in growth and development and maintenance of genome integrity, small RNAs are also important components in plant stress responses. One way in which plants respond to environmental stress is by modifying their gene expression through the activity of small RNAs. Thus, understanding how small RNAs regulate gene expression will enable researchers to explore the role of small RNAs in biotic and abiotic stress responses. This review focuses on the regulatory roles of plant small RNAs in the adaptive response to stresses. This article is part of a Special Issue entitled: Plant gene regulation in response to abiotic stress. © 2011 Elsevier B.V.

  16. How to Tackle the Challenge of siRNA Delivery with Sequence-Defined Oligoamino Amides.

    Science.gov (United States)

    Reinhard, Sören; Wagner, Ernst

    2017-01-01

    RNA interference (RNAi) as a mechanism of gene regulation provides exciting opportunities for medical applications. Synthetic small interfering RNA (siRNA) triggers the knockdown of complementary mRNA sequences in a catalytic fashion and has to be delivered into the cytosol of the targeted cells. The design of adequate carrier systems to overcome multiple extracellular and intracellular roadblocks within the delivery process has utmost importance. Cationic polymers form polyplexes through electrostatic interaction with negatively charged nucleic acids and present a promising class of carriers. Issues of polycations regarding toxicity, heterogeneity, and polydispersity can be overcome by solid-phase-assisted synthesis of sequence-defined cationic oligomers. These medium-sized highly versatile nucleic acid carriers display low cytotoxicity and can be modified and tailored in multiple ways to meet specific requirements of nucleic acid binding, polyplex size, shielding, targeting, and intracellular release of the cargo. In this way, sequence-defined cationic oligomers can mimic the dynamic and bioresponsive behavior of viruses. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Cationized dextran nanoparticle-encapsulated CXCR4-siRNA enhanced correlation between CXCR4 expression and serum alkaline phosphatase in a mouse model of colorectal cancer

    Directory of Open Access Journals (Sweden)

    Abedini F

    2012-07-01

    Full Text Available Fatemeh Abedini,1 Hossein Hosseinkhani,2 Maznah Ismail,1,3 Abraham J Domb,4 Abdul Rahman Omar,1,5 Pei Pei Chong,1,2 Po-Da Hong,3 Dah-Shyong Yu,6 Ira-Yudovin Farber41Laboratory of Molecular Biomedicine, Institute of Bioscience, Universiti Putra Malaysia, Selangor, 2Graduate Institute of Biomedical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, 3Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, Selangor, Malaysia, 4Institute of Drug Research, The Center for Nanoscience and Nanotechnology, School of Pharmacy-Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel, 5Faculty of Veterinary Medicine, Universiti Putra Malaysia, Selangor, Malaysia, 6Nanomedicine Research Center, National Defense Medical Center, Taipei, TaiwanPurpose: The failure of colorectal cancer treatments is partly due to overexpression of CXCR4 by tumor cells, which plays a critical role in cell metastasis. Moreover, serum alkaline phosphatase (ALP levels are frequently elevated in patients with metastatic colorectal cancer. A polysaccharide, dextran, was chosen as the vector of siRNA. Spermine was conjugated to oxidized dextran by reductive amination process to obtain cationized dextran, so-called dextran-spermine, in order to prepare CXCR4-siRNAs/dextran-spermine nanoparticles. The fabricated nanoparticles were used in order to investigate whether downregulation of CXCR4 expression could affect serum ALP in mouse models of colorectal cancer.Methods: Colorectal cancer was established in BALB/C mice following injection of mouse colon carcinoma cells CT.26WT through the tail vein. CXCR4 siRNA for two sites of the target gene was administered following injection of naked siRNA or siRNA encapsulated into nanoparticles.Results: In vivo animal data revealed that CXCR4 silencing by dextran-spermine nanoparticles significantly downregulated CXCR4 expression compared with naked CXCR4 siRNA. Furthermore, there was

  18. Comparing Russian and Finnish standards of water purification

    OpenAIRE

    Maria, Pupkova

    2012-01-01

    The subject of this thesis is water purification. The first aim of this thesis is to consider different ways of water purification. The second aim is to compare Finnish and Russian standards of water purification. The third one is to show water purification methods on the pattern of Mikkeli water purification plan. Water purification methods of water intended for human consumption will be described.Combined tables will be done according to the quality requirement of drinking water of both,...

  19. Computational analysis of siRNA recognition by the Ago2 PAZ domain and identification of the determinants of RNA-induced gene silencing.

    Directory of Open Access Journals (Sweden)

    Mahmoud Kandeel

    Full Text Available RNA interference (RNAi is a highly specialized process of protein-siRNA interaction that results in the regulation of gene expression and cleavage of target mRNA. The PAZ domain of the Argonaute proteins binds to the 3' end of siRNA, and during RNAi the attaching end of the siRNA switches between binding and release from its binding pocket. This biphasic interaction of the 3' end of siRNA with the PAZ domain is essential for RNAi activity; however, it remains unclear whether stronger or weaker binding with PAZ domain will facilitate or hinder the overall RNAi process. Here we report the correlation between the binding of modified siRNA 3' overhang analogues and their in vivo RNAi efficacy. We found that higher RNAi efficacy was associated with the parameters of lower Ki value, lower total intermolecular energy, lower free energy, higher hydrogen bonding, smaller total surface of interaction and fewer van der Waals interactions. Electrostatic interaction was a minor contributor to compounds recognition, underscoring the presence of phosphate groups in the modified analogues. Thus, compounds with lower binding affinity are associated with better gene silencing. Lower binding strength along with the smaller interaction surface, higher hydrogen bonding and fewer van der Waals interactions were among the markers for favorable RNAi activity. Within the measured parameters, the interaction surface, van der Waals interactions and inhibition constant showed a statistically significant correlation with measured RNAi efficacy. The considerations provided in this report will be helpful in the design of new compounds with better gene silencing ability.

  20. Purification of tritium-free water

    International Nuclear Information System (INIS)

    Hussain, S.D.

    1982-10-01

    Ground water which has been out of contact with the atmosphere for a long time as compared to the half life of tritium (12.43 years) does not contain any measureable amount of tritium. Such water is called tritium-free water. It may contain dissolved and suspended impurities and has to be purified before it can be used for the preparation of blanks and standards required in the routine measurement of low level tritium in water samples. The purification of tritium-free water by distillation in a closed system has been described. The quality of processed tritium-free water was precisely checked at International Atomic Energy Agency (IAEA) Vienna and found satisfactory. (authors)

  1. Vitreous membranes used in the biogas purification

    International Nuclear Information System (INIS)

    Ortega Viera, L.; Rodriguez Munoz, S.; Fernandez Santana, E.; Martines Ramirez, Y.; Crespo Artigas, A.; Viera Gallardo, Y.

    2016-01-01

    In the present work 10 vitreous membranes with different masses of zinc oxide (ZnO(s)) and particle diameters charcoal (DPC) are used in the purification of biogas. The porosity and tortuosity of the membranes is obtained, showing the variation with respect to the composition thereof. From these structural features specific flow of H 2 S(g) is obtained which is transferred using the Fick's diffusion equation in the membranes and its value increases with increasing mass of ZnO(s). By X-ray diffraction membrane made with 3.16 g of ZnO(s) forming zinc sulfide it is shown, so we can say that the removal of H 2 S(g) occurs by a process of absorption with chemical reaction in the membranes. (Author)

  2. Emulsion Liquid Membrane Technology in Organic Acid Purification

    International Nuclear Information System (INIS)

    Norela Jusoh; Norasikin Othman; Nur Alina Nasruddin

    2016-01-01

    Emulsion Liquid Membrane (ELM) process have shown a great potential in wide application of industrial separations such as in removal of many chemicals, organic compounds, metal ions, pollutants and biomolecules. This system promote many advantages including simple operation, high selectivity, low energy requirement, and single stage extraction and stripping process. One potential application of ELM is in the purification of succinic acid from fermentation broth. This study outline steps for developing emulsion liquid membrane process in purification of succinic acid. The steps include liquid membrane formulation, ELM stability and ELM extraction of succinic acid. Several carrier, diluent and stripping agent was screened to find appropriate membrane formulation. After that, ELM stability was investigated to enhance the recovery of succinic acid. Finally, the performance of ELM was evaluated in the extraction process. Results show that formulated liquid membrane using Amberlite LA2 as carrier, palm oil as diluent and sodium carbonate, Na_2CO_3 as stripping agent provide good performance in purification. On the other hand, the prepared emulsion was observed to be stable up to 1 hour and sufficient for extraction process. In conclusion, ELM has high potential to purify succinic acid from fermentation broth. (author)

  3. Purificação do subproduto do processo de extração de esteviosídeo Purification of the by-product of the stevioside extraction process

    Directory of Open Access Journals (Sweden)

    Denise Maria Malachini Miotto

    2004-03-01

    , CaX and MgX. Two experiments were accomplished: a test of saturation of the adsorbents to evaluate its adsorption capacity and a test for maximum clarification to determine the maximum purification reached by adsorption in zeolites. Starting from the results, it was verified that CaX is a more effective adsorbent. Zeolites can be reused up to twice, needing regeneration soon after. The test for maximum clarification showed almost clear solutions, with high clarification levels (80-90% of the compounds with larger likeness, but with high retentions of the sweeteners (~70%, because zeolites retain most of the pigments of the caramel solution, but they also drag stevioside and rebaudioside A, resulting in a process with low yield in relation to the recovery of the sweeteners, but considered satisfactory, in view that caramel, in spite of being rich in sweeteners, has no use at present.

  4. Mesoporous silica nanorods toward efficient loading and intracellular delivery of siRNA

    Science.gov (United States)

    Chen, Lijue; She, Xiaodong; Wang, Tao; Shigdar, Sarah; Duan, Wei; Kong, Lingxue

    2018-02-01

    The technology of RNA interference (RNAi) that uses small interfering RNA (siRNA) to silence the gene expression with complementary messenger RNA (mRNA) sequence has great potential for the treatment of cancer in which certain genes were usually found overexpressed. However, the carry and delivery of siRNA to the target site in the human body can be challenging for this technology to be used clinically to silence the cancer-related gene expression. In this work, rod shaped mesoporous silica nanoparticles (MSNs) were developed as siRNA delivery system for specific intracellular delivery. The rod MSNs with an aspect ratio of 1.5 had a high surface area of 934.28 m2/g and achieved a siRNA loading of more than 80 mg/g. With the epidermal growth factor (EGF) grafted on the surface of the MSNs, siRNA can be delivered to the epidermal growth factor receptor (EGFR) overexpressed colorectal cancer cells with high intracellular concentration compared to MSNs without EGF and lead to survivin gene knocking down to less than 30%.

  5. PLK-1 Silencing in Bladder Cancer by siRNA Delivered With Exosomes.

    Science.gov (United States)

    Greco, Kristin A; Franzen, Carrie A; Foreman, Kimberly E; Flanigan, Robert C; Kuo, Paul C; Gupta, Gopal N

    2016-05-01

    To use exosomes as a vector to deliver small interfering ribonucleic acid (siRNA) to silence the polo-like kinase 1 (PLK-1) gene in bladder cancer cells. Exosomes were isolated from both human embryonic kidney 293 (HEK293) cell and mesenchymal stem cell (MSC) conditioned media. Fluorescently labeled exosomes were co-cultured with bladder cancer and normal epithelial cells and uptake was quantified by image cytometry. PLK-1 siRNA and negative control siRNA were loaded into HEK293 and MSC exosomes using electroporation. An invasive bladder cancer cell line (UMUC3) was co-cultured with the electroporated exosomes. Quantitative reverse transcriptase polymerase chain reaction was performed. Protein analysis was performed by Western blot. Annexin V staining and MTT assays were used to investigate effects on apoptosis and viability. Bladder cancer cell lines internalize an increased percentage of HEK293 exosomes when compared to normal bladder epithelial cells. Treatment of UMUC3 cells with exosomes electroporated with PLK-1 siRNA achieved successful knockdown of PLK-1 mRNA and protein when compared to cells treated with negative control exosomes. HEK293 and MSC exosomes were effectively used as a delivery vector to transport PLK-1 siRNA to bladder cancer cells in vitro, resulting in selective gene silencing of PLK-1. The use of exosomes as a delivery vector for potential intravesical therapy is attractive. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Development of a Positive-readout Mouse Model of siRNA Pharmacodynamics

    Directory of Open Access Journals (Sweden)

    Mark Stevenson

    2013-01-01

    Full Text Available Development of RNAi-based therapeutics has the potential to revolutionize treatment options for a range of human diseases. However, as with gene therapy, a major barrier to progress is the lack of methods to achieve and measure efficient delivery for systemic administration. We have developed a positive-readout pharmacodynamic transgenic reporter mouse model allowing noninvasive real-time assessment of siRNA activity. The model combines a luciferase reporter gene under the control of regulatory elements from the lac operon of Escherichia coli. Introduction of siRNA targeting lac repressor results in increased luciferase expression in cells where siRNA is biologically active. Five founder luciferase-expressing and three founder Lac-expressing lines were generated and characterized. Mating of ubiquitously expressing luciferase and lac lines generated progeny in which luciferase expression was significantly reduced compared with the parental line. Administration of isopropyl β-D-1-thiogalactopyranoside either in drinking water or given intraperitoneally increased luciferase expression in eight of the mice examined, which fell rapidly when withdrawn. Intraperitoneal administration of siRNA targeting lac in combination with Lipofectamine 2000 resulted in increased luciferase expression in the liver while control nontargeting siRNA had no effect. We believe a sensitive positive readout pharmacodynamics reporter model will be of use to the research community in RNAi-based vector development.

  7. CDE-1 affects chromosome segregation through uridylation of CSR-1-bound siRNAs.

    Science.gov (United States)

    van Wolfswinkel, Josien C; Claycomb, Julie M; Batista, Pedro J; Mello, Craig C; Berezikov, Eugene; Ketting, René F

    2009-10-02

    We have studied the function of a conserved germline-specific nucleotidyltransferase protein, CDE-1, in RNAi and chromosome segregation in C. elegans. CDE-1 localizes specifically to mitotic chromosomes in embryos. This localization requires the RdRP EGO-1, which physically interacts with CDE-1, and the Argonaute protein CSR-1. We found that CDE-1 is required for the uridylation of CSR-1 bound siRNAs, and that in the absence of CDE-1 these siRNAs accumulate to inappropriate levels, accompanied by defects in both meiotic and mitotic chromosome segregation. Elevated siRNA levels are associated with erroneous gene silencing, most likely through the inappropriate loading of CSR-1 siRNAs into other Argonaute proteins. We propose a model in which CDE-1 restricts specific EGO-1-generated siRNAs to the CSR-1 mediated, chromosome associated RNAi pathway, thus separating it from other endogenous RNAi pathways. The conserved nature of CDE-1 suggests that similar sorting mechanisms may operate in other animals, including mammals.

  8. Method for ion exchange purification of sodium iodide solution from heavy metals and potassium microimpurities

    International Nuclear Information System (INIS)

    Smirnov, G.I.; Kachur, N.Ya.; Kostromina, O.N.; Ogorodnikova, A.A.; Khajnakov, S.A.

    1990-01-01

    A method of deep ion exchange purification of sodium iodide solution from heavy metals (iron, nickel, copper, lead) and potassium microimpurities is developed. The method includes multiple sorption of microimpurities on titanium phosphate with their subsequent desorption by sorbent processing with a solution with a solution of 3-6 N nitric acid, first, and then with a neutral solution of 2 % sodium thiosulfate. The given method permits to increase the purification degree of sodium iodide solution by 25-30 %. 2 tabs

  9. An automated synthesis-purification-sample-management platform for the accelerated generation of pharmaceutical candidates.

    Science.gov (United States)

    Sutherland, J David; Tu, Noah P; Nemcek, Thomas A; Searle, Philip A; Hochlowski, Jill E; Djuric, Stevan W; Pan, Jeffrey Y

    2014-04-01

    A flexible and integrated flow-chemistry-synthesis-purification compound-generation and sample-management platform has been developed to accelerate the production of small-molecule organic-compound drug candidates in pharmaceutical research. Central to the integrated system is a Mitsubishi robot, which hands off samples throughout the process to the next station, including synthesis and purification, sample dispensing for purity and quantification analysis, dry-down, and aliquot generation.

  10. SiRNAs conjugated with aromatic compounds induce RISC-mediated antisense strand selection and strong gene-silencing activity

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Takanori, E-mail: kubo-t@yasuda-u.ac.jp [Faculty of Pharmacy, Yasuda Women' s University, 6-13-1 Yasuhigashi, Asaminami-ku, Hiroshima 731-0153 (Japan); Yanagihara, Kazuyoshi [Faculty of Pharmacy, Yasuda Women' s University, 6-13-1 Yasuhigashi, Asaminami-ku, Hiroshima 731-0153 (Japan); Division of Genetics, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Takei, Yoshifumi [Department of Biochemistry, Nagoya University Graduate School of Medicine, 65 Tsurumi-cho, Showa-ku, Nagoya 466-8550 (Japan); Mihara, Keichiro [Department of Hematology and Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553 (Japan); Sato, Yuichiro; Seyama, Toshio [Faculty of Pharmacy, Yasuda Women' s University, 6-13-1 Yasuhigashi, Asaminami-ku, Hiroshima 731-0153 (Japan)

    2012-10-05

    Highlights: Black-Right-Pointing-Pointer SiRNAs conjugated with aromatic compounds (Ar-siRNAs) at 5 Prime -sense strand were synthesized. Black-Right-Pointing-Pointer Ar-siRNAs increased resistance against nuclease degradation. Black-Right-Pointing-Pointer Ar-siRNAs were thermodynamically stable compared with the unmodified siRNA. Black-Right-Pointing-Pointer High levels of cellular uptake and cytoplasmic localization were found. Black-Right-Pointing-Pointer Strong gene-silencing efficacy was exhibited in the Ar-siRNAs. -- Abstract: Short interference RNA (siRNA) is a powerful tool for suppressing gene expression in mammalian cells. In this study, we focused on the development of siRNAs conjugated with aromatic compounds in order to improve the potency of RNAi and thus to overcome several problems with siRNAs, such as cellular delivery and nuclease stability. The siRNAs conjugated with phenyl, hydroxyphenyl, naphthyl, and pyrenyl derivatives showed strong resistance to nuclease degradation, and were thermodynamically stable compared with unmodified siRNA. A high level of membrane permeability in HeLa cells was also observed. Moreover, these siRNAs exhibited enhanced RNAi efficacy, which exceeded that of locked nucleic acid (LNA)-modified siRNAs, against exogenous Renilla luciferase in HeLa cells. In particular, abundant cytoplasmic localization and strong gene-silencing efficacy were found in the siRNAs conjugated with phenyl and hydroxyphenyl derivatives. The novel siRNAs conjugated with aromatic compounds are promising candidates for a new generation of modified siRNAs that can solve many of the problems associated with RNAi technology.

  11. A High Throughput In Vivo Model for Testing Delivery and Antiviral Effects of siRNAs in Vertebrates

    DEFF Research Database (Denmark)

    Schyth, Brian Dall; Lorenzen, Niels; Pedersen, Finn Skou

    2007-01-01

    composed of small juvenile rainbow trout and a fish pathogenic virus to analyze the delivery and antiviral effects of formulated siRNAs. Intraperitoneally (IP) injected siRNAs formulated in polycationic liposomes, and to a lesser degree naked siRNAs, primarily entered free IP cells, including macrophage......-like cells. Uptake in these cells correlated with antiviral activity, seen as reduced mortality of virus-challenged fish. However, protection at the disease level was not dependent upon which of three tested siRNAs was used, and protection correlated with up-regulation of an interferon (IFN)-related gene...

  12. Purification of zirconium concentrates

    International Nuclear Information System (INIS)

    Brown, A.E.P.

    1976-01-01

    A commercial grade ZrO 2 and an ammonium uranate (yellow cake) are obtained from the caldasito ore processing. This ore is found in the Pocos de Caldas Plateau, State of Minas Gerais, Brazil. Caldasito is an uranigerous zirconium ore, a mixture of zircon and baddeleyite and contains 60% ZrO 2 and 0,3% U 3 O 8 . The chemical opening of the ore was made by alkaline fusion with NaOH at controlled temperature. The zirconium-uranium separation took place by a continuous liquid-liquid extraction in TBP-varsol-HNO 3 -H 2 O system. The raffinate containing zirconium + impurities (aluminium, iron and titanium) was purified by an ion exchange operation using a strong cationic resin [pt

  13. Review of Membranes for Helium Separation and Purification

    Directory of Open Access Journals (Sweden)

    Colin A. Scholes

    2017-02-01

    Full Text Available Membrane gas separation has potential for the recovery and purification of helium, because the majority of membranes have selectivity for helium. This review reports on the current state of the research and patent literature for membranes undertaking helium separation. This includes direct recovery from natural gas, as an ancillary stage in natural gas processing, as well as niche applications where helium recycling has potential. A review of the available polymeric and inorganic membranes for helium separation is provided. Commercial gas separation membranes in comparable gas industries are discussed in terms of their potential in helium separation. Also presented are the various membrane process designs patented for the recovery and purification of helium from various sources, as these demonstrate that it is viable to separate helium through currently available polymeric membranes. This review places a particular focus on those processes where membranes are combined in series with another separation technology, commonly pressure swing adsorption. These combined processes have the most potential for membranes to produce a high purity helium product. The review demonstrates that membrane gas separation is technically feasible for helium recovery and purification, though membranes are currently only applied in niche applications focused on reusing helium rather than separation from natural sources.

  14. Exosomes as nanocarriers for siRNA delivery: paradigms and challenges.

    Science.gov (United States)

    Shahabipour, Fahimeh; Banach, Maciej; Sahebkar, Amirhossein

    2016-12-01

    Exosomes are nano-sized vesicles that facilitate intercellular communications through carrying genetic materials and functional biomolecules. Owing to their unique size and structure, exosomes have emerged as a useful tool to overcome the limitations of siRNA delivery. The use of exosomes as siRNA delivery vehicles lacks certain disadvantages of the existing foreign delivery systems such as viruses, polycationic polymers and liposomes, and introduces several advantages including inherent capacity to pass through biological barriers and escape from phagocytosis by the reticuloendothelial system, as well as being biocompatible, non-toxic, and immunologically inert. Different strategies have been employed to harness exosome-based delivery systems, including surface modification with targeting ligands, and using exosome-display technology, virus-modified exosomes, and exosome-mimetic vesicles. The present review provides a capsule summary of the recent advances and current challenges in the field of exosome-mediated siRNA delivery.

  15. Purification of rhamnolipid using colloidal magnetic nanoparticles ...

    African Journals Online (AJOL)

    Phospholipid-coated colloidal magnetic nanoparticles with mean magnetite core size of 9 nm are shown to be effective ion exchange media for the recovery and purification of Rhaminolipid from culture mixtures. These particles have high adsorption capacity for purification (an order of magnitude larger than the best ...

  16. Targeted delivery of siRNA to macrophages for anti-inflammatory treatment.

    Science.gov (United States)

    Kim, Sang-Soo; Ye, Chunting; Kumar, Priti; Chiu, Isaac; Subramanya, Sandesh; Wu, Haoquan; Shankar, Premlata; Manjunath, N

    2010-05-01

    Inflammation mediated by tumor necrosis factor-alpha (TNF-alpha) and the associated neuronal apoptosis characterizes a number of neurologic disorders. Macrophages and microglial cells are believed to be the major source of TNF-alpha in the central nervous system (CNS). Here, we show that suppression of TNF-alpha by targeted delivery of small interfering RNA (siRNA) to macrophage/microglial cells dramatically reduces lipopolysaccharide (LPS)-induced neuroinflammation and neuronal apoptosis in vivo. Because macrophage/microglia express the nicotinic acetylcholine receptor (AchR) on their surface, we used a short AchR-binding peptide derived from the rabies virus glycoprotein (RVG) as a targeting ligand. This peptide was fused to nona-D-arginine residues (RVG-9dR) to enable siRNA binding. RVG-9dR was able to deliver siRNA to induce gene silencing in macrophages and microglia cells from wild type, but not AchR-deficient mice, confirming targeting specificity. Treatment with anti-TNF-alpha siRNA complexed to RVG-9dR achieved efficient silencing of LPS-induced TNF-alpha production by primary macrophages and microglia cells in vitro. Moreover, intravenous injection with RVG-9dR-complexed siRNA in mice reduced the LPS-induced TNF-alpha levels in blood as well as in the brain, leading to a significant reduction in neuronal apoptosis. These results demonstrate that RVG-9dR provides a tool for siRNA delivery to macrophages and microglia and that suppression of TNF-alpha can potentially be used to suppress neuroinflammation in vivo.

  17. Screening nylon-3 polymers, a new class of cationic amphiphiles, for siRNA delivery.

    Science.gov (United States)

    Nadithe, Venkatareddy; Liu, Runhui; Killinger, Bryan A; Movassaghian, Sara; Kim, Na Hyung; Moszczynska, Anna B; Masters, Kristyn S; Gellman, Samuel H; Merkel, Olivia M

    2015-02-02

    Amphiphilic nucleic acid carriers have attracted strong interest. Three groups of nylon-3 copolymers (poly-β-peptides) possessing different cationic/hydrophobic content were evaluated as siRNA delivery agents in this study. Their ability to condense siRNA was determined in SYBR Gold assays. Their cytotoxicity was tested by MTT assays, their efficiency of delivering Alexa Fluor-488-labeled siRNA intracellularly in the presence and absence of uptake inhibitors was assessed by flow cytometry, and their transfection efficacies were studied by luciferase knockdown in a cell line stably expressing luciferase (H1299/Luc). Endosomal release was determined by confocal laser scanning microscopy and colocalization with lysotracker. All polymers efficiently condensed siRNA at nitrogen-to-phosphate (N/P) ratios of 5 or lower, as reflected in hydrodynamic diameters smaller than that at N/P 1. Although several formulations had negative zeta potentials at N/P 1, G2C and G2D polyplexes yielded >80% uptake in H1299/Luc cells, as determined by flow cytometry. Luciferase knockdown (20-65%) was observed after transfection with polyplexes made of the high molecular weight polymers that were the most hydrophobic. The ability of nylon-3 polymers to deliver siRNA intracellularly even at negative zeta potential implies that they mediate transport across cell membranes based on their amphiphilicity. The cellular uptake route was determined to strongly depend on the presence of cholesterol in the cell membrane. These polymers are, therefore, very promising for siRNA delivery at reduced surface charge and toxicity. Our study identified nylon-3 formulations at low N/P ratios for effective gene knockdown, indicating that nylon-3 polymers are a new, promising type of gene delivery agent.

  18. Screening Nylon-3 Polymers, a New Class of Cationic Amphiphiles, for siRNA Delivery

    Science.gov (United States)

    2015-01-01

    Amphiphilic nucleic acid carriers have attracted strong interest. Three groups of nylon-3 copolymers (poly-β-peptides) possessing different cationic/hydrophobic content were evaluated as siRNA delivery agents in this study. Their ability to condense siRNA was determined in SYBR Gold assays. Their cytotoxicity was tested by MTT assays, their efficiency of delivering Alexa Fluor-488-labeled siRNA intracellularly in the presence and absence of uptake inhibitors was assessed by flow cytometry, and their transfection efficacies were studied by luciferase knockdown in a cell line stably expressing luciferase (H1299/Luc). Endosomal release was determined by confocal laser scanning microscopy and colocalization with lysotracker. All polymers efficiently condensed siRNA at nitrogen-to-phosphate (N/P) ratios of 5 or lower, as reflected in hydrodynamic diameters smaller than that at N/P 1. Although several formulations had negative zeta potentials at N/P 1, G2C and G2D polyplexes yielded >80% uptake in H1299/Luc cells, as determined by flow cytometry. Luciferase knockdown (20–65%) was observed after transfection with polyplexes made of the high molecular weight polymers that were the most hydrophobic. The ability of nylon-3 polymers to deliver siRNA intracellularly even at negative zeta potential implies that they mediate transport across cell membranes based on their amphiphilicity. The cellular uptake route was determined to strongly depend on the presence of cholesterol in the cell membrane. These polymers are, therefore, very promising for siRNA delivery at reduced surface charge and toxicity. Our study identified nylon-3 formulations at low N/P ratios for effective gene knockdown, indicating that nylon-3 polymers are a new, promising type of gene delivery agent. PMID:25437915

  19. Targeted Sterically Stabilized Phospholipid siRNA Nanomedicine for Hepatic and Renal Fibrosis

    Directory of Open Access Journals (Sweden)

    Fatima Khaja

    2016-01-01

    Full Text Available Since its discovery, small interfering RNA (siRNA has been considered a potent tool for modulating gene expression. It has the ability to specifically target proteins via selective degradation of messenger RNA (mRNA not easily accessed by conventional drugs. Hence, RNA interference (RNAi therapeutics have great potential in the treatment of many diseases caused by faulty protein expression such as fibrosis and cancer. However, for clinical application siRNA faces a number of obstacles, such as poor in vivo stability, and off-target effects. Here we developed a unique targeted nanomedicine to tackle current siRNA delivery issues by formulating a biocompatible, biodegradable and relatively inexpensive nanocarrier of sterically stabilized phospholipid nanoparticles (SSLNPs. This nanocarrier is capable of incorporating siRNA in its core through self-association with a novel cationic lipid composed of naturally occuring phospholipids and amino acids. This overall assembly protects and delivers sufficient amounts of siRNA to knockdown over-expressed protein in target cells. The siRNA used in this study, targets connective tissue growth factor (CTGF, an important regulator of fibrosis in both hepatic and renal cells. Furthermore, asialoglycoprotein receptors are targeted by attaching the galactosamine ligand to the nanocarries which enhances the uptake of nanoparticles by hepatocytes and renal tubular epithelial cells, the major producers of CTGF in fibrosis. On animals this innovative nanoconstruct, small interfering RNA in sterically stabilized phospholipid nanoparticles (siRNA-SSLNP, showed favorable pharmacokinetic properties and accumulated mostly in hepatic and renal tissues making siRNA-SSLNP a suitable system for targeting liver and kidney fibrotic diseases.

  20. Diatomite biosilica nanocarriers for siRNA transport inside cancer cells.

    Science.gov (United States)

    Rea, Ilaria; Martucci, Nicola M; De Stefano, Luca; Ruggiero, Immacolata; Terracciano, Monica; Dardano, Principia; Migliaccio, Nunzia; Arcari, Paolo; Taté, Rosarita; Rendina, Ivo; Lamberti, Annalisa

    2014-12-01

    Diatomite is a natural porous biomaterial of sedimentary origin, formed by fragments of diatom siliceous skeletons, called "frustules". Due to large availability in many areas of the world, chemical stability, and non-toxicity, these fossil structures have been widespread used in lot of industrial applications, such as food production, water extracting agent, production of cosmetics and pharmaceutics. However, diatomite is surprisingly still rarely used in biomedical applications. In this work, we exploit diatomite nanoparticles for small interfering ribonucleic acid (siRNA) transport inside human epidermoid cancer cells (H1355). Morphology and composition of diatomite microfrustules (average size lower than 40μm) are investigated by scanning electron microscopy equipped by energy dispersive X-ray spectroscopy, Fourier transform infrared analysis, and photoluminescence measurements. Nanometric porous particles (average size lower than 450nm) are obtained by mechanical crushing, sonication, and filtering of micrometric frustules. siRNA bioconjugation is performed on both micrometric and nanometric fragments by silanization. In-vitro experiments show very low toxicity on exposure of the cells to diatomite nanoparticle concentration up to 300μg/ml for 72h. Confocal microscopy imaging performed on cancer cells incubated with siRNA conjugated nanoparticles demonstrates a cytoplasmatic localization of vectors. Gene silencing by delivered siRNA is also demonstrated. Our studies endorse diatomite nanoparticles as non-toxic nanocarriers for siRNA transport in cancer cells. siRNA is a powerful molecular tool for cancer treatment but its delivery is inefficient due to the difficulty to penetrate the cell membrane. siRNA-diatomite nanoconjugate may be well suited for delivery of therapeutic to cancer cells. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. RDE-4 preferentially binds long dsRNA and its dimerization is necessary for cleavage of dsRNA to siRNA.

    Science.gov (United States)

    Parker, Greg S; Eckert, Debra M; Bass, Brenda L

    2006-05-01

    In organisms ranging from Arabidopsis to humans, Dicer requires dsRNA-binding proteins (dsRBPs) to carry out its roles in RNA interference (RNAi) and micro-RNA (miRNA) processing. In Caenorhabditis elegans, the dsRBP RDE-4 acts with Dicer during the initiation of RNAi, when long dsRNA is cleaved to small interfering RNAs (siRNAs). RDE-4 is not required in subsequent steps, and how RDE-4 distinguishes between long dsRNA and short siRNA is unclear. We report the first detailed analysis of RDE-4 binding, using purified recombinant RDE-4 and various truncated proteins. We find that, similar to other dsRBPs, RDE-4 is not sequence-specific. However, consistent with its in vivo roles, RDE-4 binds with higher affinity to long dsRNA. We also observe that RDE-4 is a homodimer in solution, and that the C-terminal domain of the protein is required for dimerization. Using extracts from wild-type and rde-4 mutant C. elegans, we show that the C-terminal dimerization domain is required for the production of siRNA. Our findings suggest a model for RDE-4 function during the initiation of RNAi.

  2. PRL-3 siRNA inhibits the metastasis of B16-BL6 mouse melanoma cells in vitro and in vivo.

    Science.gov (United States)

    Qian, Feng; Li, Yu-Pei; Sheng, Xia; Zhang, Zi-Chao; Song, Ran; Dong, Wei; Cao, Shao-Xian; Hua, Zi-Chun; Xu, Qiang

    2007-01-01

    Phosphatase of regenerating liver-3 (PRL-3) has been proposed to promote the invasion of tumor cells to metastasis sites. However, the effect of PRL-3 on spontaneous metastasis has not been clearly demonstrated, and whether PRL-3 could become a new therapeutic target in malignant tumor is still unknown. In this study, we used PRL-3 siRNA as a molecular medicine to specifically reduce the expression of PRL-3 in B16-BL6 cells, a highly metastatic melanoma cell line. In vitro, PRL-3 siRNA significantly inhibited cell adhesion and migration, but had no effect on cell proliferation. In the spontaneous metastatic tumor model in vivo, PRL-3 siRNA treatment remarkably inhibited the proliferation of primary tumor, prevented tumor cells from invading the draining lymph nodes, and prolonged the life span of mice. Therefore, our results indicate that PRL-3 plays a critical role in promoting the whole process of spontaneous metastasis and tumor growth initiation, and that inhibiting PRL-3 will improve malignant tumor therapy.

  3. RNA interference-based therapeutics for human immunodeficiency virus HIV-1 treatment: synthetic siRNA or vector-based shRNA?

    Science.gov (United States)

    Subramanya, Sandesh; Kim, Sang-Soo; Manjunath, N; Shankar, Premlata

    2010-02-01

    Despite the clinical benefits of highly active antiretroviral therapy (HAART), the prospect of life-long antiretroviral treatment poses significant problems, which has spurred interest in developing new drugs and strategies to treat HIV infection and eliminate persistent viral reservoirs. RNAi has emerged as a therapeutic possibility for HIV. We discuss progress in overcoming hurdles to translating transient and stable RNAi enabling technologies to clinical application for HIV; covering the past 2 - 3 years. HIV inhibition can be achieved by transfection of chemically or enzymatically synthesized siRNAs or by DNA-based vector systems expressing short hairpin RNAs (shRNAs) that are processed intracellularly into siRNA. We compare these approaches, focusing on technical and safety issues that will guide the choice of strategy for clinical use. Introduction of synthetic siRNA into cells or its stable endogenous production using vector-driven shRNA have been shown to suppress HIV replication in vitro and, in some instances, in vivo. Each method has advantages and limitations in terms of ease of delivery, duration of silencing, emergence of escape mutants and potential toxicity. Both appear to have potential as future therapeutics for HIV, once the technical and safety issues of each approach are overcome.

  4. Ion exchange purification of scandium

    Science.gov (United States)

    Herchenroeder, Laurie A.; Burkholder, Harvey R.

    1990-10-23

    An improvement in purification of scandium through ion exchange chromatography is disclosed in which the oxidation potential of the eluting solution is altered by the addition of potassium chlorate or ammonium chloride so that removal of contaminants is encouraged. The temperature, pH and concentration of the eluent HEDTA are controlled in order to maintain the scandium in the column while minimizing dilution of the scandium band. Recovery of scandium is improved by pumping dilute scandium over the column prior to stripping the scandium and precipitation. This eliminates the HEDTA ion and other monovalent cations contaminating the scandium band. This method maximizes recovery of scandium while maintaining purity.

  5. Aqueous Chloride Operations Overview: Plutonium and Americium Purification/Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, Kyle Shelton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kimball, David Bryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Skidmore, Bradley Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-28

    These are a set of slides intended for an information session as part of recruiting activities at Brigham Young University. It gives an overview of aqueous chloride operations, specifically on plutonium and americium purification/recovery. This presentation details the steps taken perform these processes, from plutonium size reduction, dissolution, solvent extraction, oxalate precipitation, to calcination. For americium recovery, it details the CLEAR (chloride extraction and actinide recovery) Line, oxalate precipitation and calcination.

  6. On the Importance of Purification of Sodium Polystyrene Sulfonate

    OpenAIRE

    Sen, Akhil K.; Roy, Sandip; Juvekar, Vinay A.

    2012-01-01

    Ion exchange is commonly employed for purification of sodium polystyrene sulfonate (NaPSS), a molecule widely used as a model polyelectrolyte. However, the present work demonstrates that the ion exchange process itself may introduce some extraneous species into NaPSS samples by two possible mechanisms: (i) chemical transformation of polystyrene sulfonic acid (HPSS), a relatively unstable intermediate formed during ion exchange and (ii) release of small amount of “condensed” acid from cationic...

  7. Robotic high-throughput purification of affinity-tagged recombinant proteins.

    Science.gov (United States)

    Wiesler, Simone C; Weinzierl, Robert O J

    2015-01-01

    Affinity purification of recombinant proteins has become the method of choice to obtain good quantities and qualities of proteins for a variety of downstream biochemical applications. While manual or FPLC-assisted purification techniques are generally time-consuming and labor-intensive, the advent of high-throughput technologies and liquid handling robotics has simplified and accelerated this process significantly. Additionally, without the human factor as a potential source of error, automated purification protocols allow for the generation of large numbers of proteins simultaneously and under directly comparable conditions. The delivered material is ideal for activity comparisons of different variants of the same protein. Here, we present our strategy for the simultaneous purification of up to 24 affinity-tagged proteins for activity measurements in biochemical assays. The protocol described is suitable for the scale typically required in individual research laboratories.

  8. Enriched Water-H2 18O Purification to be Used in Routine 18FDG Production

    International Nuclear Information System (INIS)

    Al Rayyes, A.H.

    2009-01-01

    Oxygen-18 enriched water has been recovered from IBA (Ion Beam Applications) recovery system followed by purification and then used in the production of 18 F-. The purification process has been carried out by irradiation with UV followed by a distillation under vacuum. After purification, 95% of water is recovered and organic compounds, radioisotopes, trace metals and gases are eliminated efficiently. Results show that there are no significant differences in (2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG) production yield using purified water by the proposed method and new enriched water. Tritium was detected in the irradiated enriched water. Contamination precautions during purification should be considered. Tritium was not present in 18 FDG or Na- 18 F final products. (author)

  9. Radiation purification of water from cyanides

    International Nuclear Information System (INIS)

    Piskarev, I.M.; Rylova, A.E.; Sevast'yanov, A.I.

    1994-01-01

    Attempts at performing the process of radiation purification of water from cyanides have been described in the literature and were briefly reviewed earlier. Sodium cyanide solutions were examined in a concentration range from 26 mg/l to 80 g/l. The data given in various publications often disagree. Radiation yields of cyanide decay vary from 0.48 to 28 molecule/100 eV for equal dose rates, according to the data presented by various authors, and the maximum yield of 1200 was attained at a low dose rate (0.18 kGy/h) in a neutral solution. Chain decomposition of cyanides was observed in some studies, but not in others; the acidity of the solution examined was not necessarily reported. It was specified that complete decomposition of cyanides occurs; however, no detection limits for the analytical procedures of cyanide determination were reported. The authors performed experiments on the purification of actual industrial waste waters (solution and slurry), which were preliminarily preserved with sodium hydroxide (pH 9; the cyanide content was 90 mg/1). Solutions in dishes 40 mm in diameter and 20 or 40 mm in height were exposed to X-rays with a maximum energy of bremsstrahlung spectrum of 70 keV. Volumes of the solutions were 20 and 40 ml. With consideration for angular divergence and beam attenuation by solution, the average absorbed-dose rates were 1.5 and 3.1 kGy/h for dishes of V equal to 40 and 20 ml, respectively. Measurements of the absorbed dose were made with a ferrosulfate dosimeter

  10. Cationic star-shaped polymer as an siRNA carrier for reducing MMP-9 expression in skin fibroblast cells and promoting wound healing in diabetic rats

    Directory of Open Access Journals (Sweden)

    Li N

    2014-07-01

    Full Text Available Na Li,1,* Heng-Cong Luo,1,* Chuan Yang,1 Jun-Jie Deng,2 Meng Ren,1 Xiao-Ying Xie,1 Diao-Zhu Lin,1 Li Yan,1 Li-Ming Zhang2 1Department of Endocrinology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, People’s Republic of China; 2DSAPM Lab and PCFM Lab, Institute of Polymer Science, Department of Polymer and Materials Science, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, People’s Republic of China *These authors contributed equally to this work Background: Excessive expression of matrix metalloproteinase-9 (MMP-9 is deleterious to the cutaneous wound-healing process in the context of diabetes. The aim of the present study was to explore whether a cationic star-shaped polymer consisting of ß-cyclodextrin (ß-CD core and poly(amidoamine dendron arms (ß-CD-[D3]7 could be used as the gene carrier of small interfering RNA (siRNA to reduce MMP-9 expression for enhanced diabetic wound healing. Methods: The cytotoxicity of ß-CD-(D37 was investigated by 3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay (MMT method in the rat CRL1213 skin fibroblast cell line. The transfection efficiency of ß-CD-(D37/MMP-9-small interfering RNA (siRNA complexes was determined by confocal microscopy and flow cytometry. Quantitative real time (RT polymerase chain reaction was performed to measure the gene expression of MMP-9 after the transfection by ß-CD-(D37/MMP-9-siRNA complexes. The ß-CD-(D37/MMP-9-siRNA complexes were injected on the wounds of streptozocin-induced diabetic rats. Wound closure was measured on days 4 and 7 post-wounding. Results: ß-CD-(D37 exhibited low cytotoxicity in fibroblast cells, and easily formed the complexes with MMP-9-siRNA. The ß-CD-(D37/MMP-9-siRNA complexes were readily taken up by fibroblast cells, resulting in the downregulation of MMP-9 gene expression (P<0.01. Animal experiments revealed that the treatment by ß-CD-(D37/MMP-9-siRNA complexes enhanced wound

  11. Secretory immunoglobulin purification from whey by chromatographic techniques.

    Science.gov (United States)

    Matlschweiger, Alexander; Engelmaier, Hannah; Himmler, Gottfried; Hahn, Rainer

    2017-08-15

    Secretory immunoglobulins (SIg) are a major fraction of the mucosal immune system and represent potential drug candidates. So far, platform technologies for their purification do not exist. SIg from animal whey was used as a model to develop a simple, efficient and potentially generic chromatographic purification process. Several chromatographic stationary phases were tested. A combination of two anion-exchange steps resulted in the highest purity. The key step was the use of a small-porous anion exchanger operated in flow-through mode. Diffusion of SIg into the resin particles was significantly hindered, while the main impurities, IgG and serum albumin, were bound. In this step, initial purity was increased from 66% to 89% with a step yield of 88%. In a second anion-exchange step using giga-porous material, SIg was captured and purified by step or linear gradient elution to obtain fractions with purities >95%. For the step gradient elution step yield of highly pure SIg was 54%. Elution of SIgA and SIgM with a linear gradient resulted in a step yield of 56% and 35%, respectively. Overall yields for both anion exchange steps were 43% for the combination of flow-through and step elution mode. Combination of flow-through and linear gradient elution mode resulted in a yield of 44% for SIgA and 39% for SIgM. The proposed process allows the purification of biologically active SIg from animal whey in preparative scale. For future applications, the process can easily be adopted for purification of recombinant secretory immunoglobulin species. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Uranium hexafluoride purification; Purificacao de hexafluoreto de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Eneas F. de

    1986-07-01

    Uranium hexafluoride might contain a large amount of impurities after manufacturing or handling. Three usual methods of purification of uranium hexafluoride were presented: selective sorption, sublimation, and distillation. Since uranium hexafluoride usually is contaminated with hydrogen fluoride, a theoretical study of the phase equilibrium properties was performed for the binary system UF{sub 6}-HF. A large deviation from the ideal solution behaviour was observed. A purification unity based on a constant reflux batch distillation process was developed. A procedure was established in order to design the re boiler, condenser and packed columns for the UF{sub 6}-HF mixture separation. A bench scale facility for fractional distillation of uranium hexafluoride was described. Basic operations for that facility and results extracted from several batches were discussed. (author)

  13. Fission-product transfer in the TMI-2 purification system

    International Nuclear Information System (INIS)

    Cox, T.E.

    1982-01-01

    The makeup purification system at TMI-2 operated during the course of the accident, processing water from the reactor coolant system cold leg at an average flow rate not exceeding 4.4 x 10 - 3 m 3 /s. The system operated through most of 28 March 1979, finally being shutdown when the system filters or demineralizers, or both, plugged and overpressured. The system was restored to service on 29 March 1979 at a flow rate of about 1.6 x 10 - 3 m 3 /s. Subsequent radiation readings of the system filters and demineralizer cubicles revealed that these components contained appreciable levels of radionuclides. One project being implemented within the Radiation and Environment Program of the Technical Integration Office is to analyze the demineralizer resins and filters, as they are removed from the makeup purification system. The object is to determine the quantity and composition of the material retained by the resins and filters

  14. Drinking water purification in the Czech Republic and worldwide

    International Nuclear Information System (INIS)

    Krmela, Jan; Beckova, Vera; Vlcek, Jaroslav; Marhol, Milan

    2012-06-01

    The report is structured as follows: (i) Legislative (hygienic) requirements for technologies applied to drinking water purification with focus on uranium elimination; (ii) Technological drinking water treatment processes (settling, filtration, precipitation, acidification, iron and manganese removal) ; (iii) State Office for Nuclear Safety requirements for the operation of facilities to separate uranium from drinking water and for the handling of saturated ionexes from such facilities; (iv) Material requirements for the operation of ionex filters serving to separate uranium from drinking water; (v) Effect of enhanced uranium concentrations in drinking waters on human body; (vi) Uranium speciation in ground waters; (vii) Brief description of technologies which are used worldwide for uranium removal; (viii) Technologies which are usable and are used in the Czech Republic for drinking water purification from uranium; (ix) Inorganic and organic ion exchangers and sorbents. (P.A.)

  15. Preparative Purification of Recombinant Proteins: Current Status and Future Trends

    Directory of Open Access Journals (Sweden)

    Mayank Saraswat

    2013-01-01

    Full Text Available Advances in fermentation technologies have resulted in the production of increased yields of proteins of economic, biopharmaceutical, and medicinal importance. Consequently, there is an absolute requirement for the development of rapid, cost-effective methodologies which facilitate the purification of such products in the absence of contaminants, such as superfluous proteins and endotoxins. Here, we provide a comprehensive overview of a selection of key purification methodologies currently being applied in both academic and industrial settings and discuss how innovative and effective protocols such as aqueous two-phase partitioning, membrane chromatography, and high-performance tangential flow filtration may be applied independently of or in conjunction with more traditional protocols for downstream processing applications.

  16. Purification of simple substances by distillation with impurity hydrothermal oxidation

    International Nuclear Information System (INIS)

    Kalashnik, O.N.; Nisel'son, L.A.

    1987-01-01

    A possibility of applying distillation method in water vapours for purification of simple substances from impurities is studied. Based on thermodynamic analysis of interaction processes in E-H 2 O system, conducted using a computer, it is as certained that SS, Se, Te, As, Cd, Hg can be purified from the majority of the impurities analysed by distillation in a water vapour flow. Behaviour of Zn, C, Ge, Al, Sb characteristic impurities under cadmium, arsenic and tellurium distillation is studied. Experiments on cadmium, arsenic and tellurium purification have confirmed, that distillation with hydrothermal oxidation of Zn, C, Ge impurities sometimes appears to be a more effective method as compared to distillation in a hydrogen flow

  17. Breathing Air Purification for Hyperbaric Purposes, Part II

    Directory of Open Access Journals (Sweden)

    Woźniak Arkadiusz

    2015-03-01

    Full Text Available Determining the efficiency of breathing air purification for hyperbaric purposes with the use of filtration systems is of a crucial importance. However, when the Polish Navy took samples of breathing air from their own filtration plant for quality purposes, these were found to not meet the required standard. The identification of this problem imposed the need to undertake actions aimed at the elimination of the identified disruptions in the process of breathing air production, with the objective of assuring its proper quality. This study presents the results of the initial tests on the air supply sources utilised by the Polish Navy, which were carried out for the purpose of setting a proper direction of future works and implementing corrective measures in order to optimise the breathing air production process. The obtained test results will be used in a subsequent publication devoted to the assessment of the level of efficiency of air purification with the use of a multifaceted approach consisting in the utilisation of various types of air supply sources and different configurations of purification systems.

  18. Influence of the drying method in chitosans purification step

    International Nuclear Information System (INIS)

    Fonseca, Ana C.M.; Batista, Jorge G.S.; Bettega, Antonio; Lima, Nelson B. de

    2015-01-01

    Currently, the study of extracellular biopolymers properties has received prominence for being easy extraction and purification. Chitosan has been an attractive proposition for applications in various fields such as engineering, biotechnology, medicine and pharmacology. For such applications, it is necessary purification of chitosan to obtain a product more concentrated and free of undesirable impurities. However, at this stage of the process of obtaining the biopolymer may occur morphological and physicochemical changes. This study evaluated the influence of the drying process after purification of a commercial chitosan sample and the importance of this step and its cost/benefit in applications requiring a high degree of purity. The method of drying influenced in the organoleptic properties and in the main characteristics of material. Analysis of the crystal structure by X-ray diffraction showed that the degree of crystallinity, X (%), in the purified chitosan samples was lower when compared with the unpurified sample. The degree of acetylation, DA (%), was analyzed by spectroscopy infrared with no significant changes on the three drying methods assessed, unlike the viscosimetric molecular weight, M_v, determined by capillary viscometry. (author)

  19. A comprehensive review on biodiesel purification and upgrading

    Directory of Open Access Journals (Sweden)

    Hamed Bateni

    2017-09-01

    Full Text Available Serious environmental concerns regarding the use of fossil-based fuels have raised awareness regarding the necessity of alternative clean fuels and energy carriers. Biodiesel is considered a clean, biodegradable, and non-toxic diesel substitute produced via the transesterification of triglycerides with an alcohol in the presence of a proper catalyst. After initial separation of the by-product (glycerol, the crude biodiesel needs to be purified to meet the standard specifications prior to marketing. The presence of impurities in the biodiesel not only significantly affects its engine performance but also complicates its handling and storage. Therefore, biodiesel purification is an essential step prior to marketing. Biodiesel purification methods can be classified based on the nature of the process into equilibrium-based, affinity-based, membrane-based, reaction-based, and solid-liquid separation processes. The main adverse properties of biodiesel – namely moisture absorption, corrosiveness, and high viscosity – primarily arise from the presence of oxygen. To address these issues, several upgrading techniques have been proposed, among which catalytic (hydrodeoxygenation using conventional hydrotreating catalysts, supported metallic materials, and most recently transition metals in various forms appear promising. Nevertheless, catalyst deactivation (via coking and/or inadequacy of product yields necessitate further research. This paper provides a comprehensive overview on the techniques and methods used for biodiesel purification and upgrading.

  20. siRNA transfection in larvae of the barnacle Amphibalanus amphitrite

    KAUST Repository

    Zhang, G.

    2015-06-25

    RNA interference (RNAi) provides an efficient and specific technique for functional genomic studies. Yet, no successful application of RNAi has been reported in barnacles. In this study, siRNA against p38 MAPK was synthesized and then transfected into A. amphitrite larvae at either the nauplius or cyprid stage, or at both stages. Effects of siRNA transfection on the p38 MAPK level were hardly detectable in the cyprids when they were transfected at the nauplius stage. In contrast, larvae that were transfected at the cyprid stage showed lower levels of p38 MAPK than the blank and reagent controls. However, significantly decreased levels of phosphorylated p38 MAPK (pp38 MAPK) and reduced settlement rates were observed only in ‘double transfections’, in which larvae were exposed to siRNA solution at both the nauplius and cyprid stages. A relatively longer transfection time and more larval cells directly exposed to siRNA might explain the higher efficiency of double transfection experiments.

  1. Gold nanoclusters-assisted delivery of NGF siRNA for effective treatment of pancreatic cancer

    Science.gov (United States)

    Lei, Yifeng; Tang, Lixue; Xie, Yangzhouyun; Xianyu, Yunlei; Zhang, Lingmin; Wang, Peng; Hamada, Yoh; Jiang, Kai; Zheng, Wenfu; Jiang, Xingyu

    2017-01-01

    Pancreatic cancer is one of the deadliest human cancers, whose progression is highly dependent on the nervous microenvironment. The suppression of gene expression of nerve growth factor (NGF) may have great potential in pancreatic cancer treatment. Here we show that gold nanocluster-assisted delivery of siRNA of NGF (GNC–siRNA) allows efficient NGF gene silencing and pancreatic cancer treatment. The GNC–siRNA complex increases the stability of siRNA in serum, prolongs the circulation lifetime of siRNA in blood and enhances the cellular uptake and tumour accumulation of siRNA. The GNC–siRNA complex potently downregulates the NGF expression in Panc-1 cells and in pancreatic tumours, and effectively inhibits the tumour progression in three pancreatic tumour models (subcutaneous model, orthotopic model and patient-derived xenograft model) without adverse effects. Our study constitutes a straightforward but effective approach to inhibit pancreatic cancer via NGF knockdown, suggesting a promising therapeutic direction for pancreatic cancer. PMID:28440296

  2. Novel siRNA formulation to effectively knockdown mutant p53 in osteosarcoma.

    Science.gov (United States)

    Kundu, Anup K; Iyer, Swathi V; Chandra, Sruti; Adhikari, Amit S; Iwakuma, Tomoo; Mandal, Tarun K

    2017-01-01

    The tumor suppressor p53 plays a crucial role in the development of osteosarcoma. The primary objective of this study is to develop and optimize lipid based nanoparticle formulations that can carry siRNA and effectively silence mutant p53 in 318-1, a murine osteosarcoma cell line. The nanoparticles were composed of a mixture of two lipids (cholesterol and DOTAP) and either PLGA or PLGA-PEG and prepared by using an EmulsiFlex-B3 high pressure homogenizer. A series of studies that include using different nanoparticles, different amount of siRNAs, cell numbers, incubation time, transfection media volume, and storage temperature was performed to optimize the gene silencing efficiency. Replacement of lipids by PLGA or PLGA-PEG decreased the particle size and overall cytotoxicity. Among all lipid-polymer nanoformulations, nanoparticles with 10% PLGA showed highest mutant p53 knockdown efficiency while maintaining higher cell viability when a nanoparticle to siRNA ratio equal to 6.8:0.66 and 75 nM siRNA was used. With long term storage the mutant p53 knockdown efficiency decreased to a greater extent. This study warrants a future evaluation of this formulation for gene silencing efficiency of mutant p53 in tissue culture and animal models for the treatment of osteosarcoma.

  3. Novel siRNA formulation to effectively knockdown mutant p53 in osteosarcoma.

    Directory of Open Access Journals (Sweden)

    Anup K Kundu

    Full Text Available The tumor suppressor p53 plays a crucial role in the development of osteosarcoma. The primary objective of this study is to develop and optimize lipid based nanoparticle formulations that can carry siRNA and effectively silence mutant p53 in 318-1, a murine osteosarcoma cell line.The nanoparticles were composed of a mixture of two lipids (cholesterol and DOTAP and either PLGA or PLGA-PEG and prepared by using an EmulsiFlex-B3 high pressure homogenizer. A series of studies that include using different nanoparticles, different amount of siRNAs, cell numbers, incubation time, transfection media volume, and storage temperature was performed to optimize the gene silencing efficiency.Replacement of lipids by PLGA or PLGA-PEG decreased the particle size and overall cytotoxicity. Among all lipid-polymer nanoformulations, nanoparticles with 10% PLGA showed highest mutant p53 knockdown efficiency while maintaining higher cell viability when a nanoparticle to siRNA ratio equal to 6.8:0.66 and 75 nM siRNA was used. With long term storage the mutant p53 knockdown efficiency decreased to a greater extent.This study warrants a future evaluation of this formulation for gene silencing efficiency of mutant p53 in tissue culture and animal models for the treatment of osteosarcoma.

  4. Hydrogel doped with nanoparticles for local sustained release of siRNA in breast cancer.

    Science.gov (United States)

    Segovia, Nathaly; Pont, Maria; Oliva, Nuria; Ramos, Victor; Borrós, Salvador; Artzi, Natalie

    2015-01-28

    Of all the much hyped and pricy cancer drugs, the benefits from the promising siRNA small molecule drugs are limited. Lack of efficient delivery vehicles that would release the drug locally, protect it from degradation, and ensure high transfection efficiency, precludes it from fulfilling its full potential. This work presents a novel platform for local and sustained delivery of siRNA with high transfection efficiencies both in vitro and in vivo in a breast cancer mice model. siRNA protection and high transfection efficiency are enabled by their encapsulation in oligopeptide-terminated poly(β-aminoester) (pBAE) nanoparticles. Sustained delivery of the siRNA is achieved by the enhanced stability of the nanoparticles when embedded in a hydrogel scaffold based on polyamidoamine (PAMAM) dendrimer cross-linked with dextran aldehyde. The combination of oligopeptide-terminated pBAE polymers and biodegradable hydrogels shows improved transfection efficiency in vivo even when compared with the most potent commercially available transfection reagents. These results highlight the advantage of using composite materials for successful delivery of these highly promising small molecules to combat cancer. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Dual-Functional Nanoparticles Targeting CXCR4 and Delivering Antiangiogenic siRNA Ameliorate Liver Fibrosis.

    Science.gov (United States)

    Liu, Chun-Hung; Chan, Kun-Ming; Chiang, Tsaiyu; Liu, Jia-Yu; Chern, Guann-Gen; Hsu, Fu-Fei; Wu, Yu-Hsuan; Liu, Ya-Chi; Chen, Yunching

    2016-07-05

    The progression of liver fibrosis, an intrinsic response to chronic liver injury, is associated with hepatic hypoxia, angiogenesis, abnormal inflammation, and significant matrix deposition, leading to the development of cirrhosis and hepatocellular carcinoma (HCC). Due to the complex pathogenesis of liver fibrosis, antifibrotic drug development has faced the challenge of efficiently and specifically targeting multiple pathogenic mechanisms. Therefore, CXCR4-targeted nanoparticles (NPs) were formulated to deliver siRNAs against vascular endothelial growth factor (VEGF) into fibrotic livers to block angiogenesis during the progression of liver fibrosis. AMD3100, a CXCR4 antagonist that was incorporated into the NPs, served dual functions: it acted as a targeting moiety and suppressed the progression of fibrosis by inhibiting the proliferation and activation of hepatic stellate cells (HSCs). We demonstrated that CXCR4-targeted NPs could deliver VEGF siRNAs to fibrotic livers, decrease VEGF expression, suppress angiogenesis and normalize the distorted vessels in the fibrotic livers in the carbon tetrachloride (CCl4) induced mouse model. Moreover, blocking SDF-1α/CXCR4 by CXCR4-targeted NPs in combination with VEGF siRNA significantly prevented the progression of liver fibrosis in CCl4-treated mice. In conclusion, the multifunctional CXCR4-targeted NPs delivering VEGF siRNAs provide an effective antifibrotic therapeutic strategy.

  6. siRNAs targeting PB2 and NP genes potentially inhibit replication

    Indian Academy of Sciences (India)

    % and has caused the death or culling of millions of poultry since 2003. In this study, we have designed three siRNAs (PB2-2235, PB2-479 and NP-865) targeting PB2 and NP genes of avian influenza virus and evaluated their potential, ...

  7. Synthesis and Gene Silencing Properties of siRNAs Containing Terminal Amide Linkages

    Directory of Open Access Journals (Sweden)

    Maria Gaglione

    2014-01-01

    Full Text Available The active components of the RNAi are 21 nucleotides long dsRNAs containing a 2 nucleotide overhang at the 3′ end, carrying 5′-phosphate and 3′-hydroxyl groups (siRNAs. Structural analysis revealed that the siRNA is functionally bound at both ends to RISC. Terminal modifications are considered with interest as the introduction of chemical moieties interferes with the 3′ overhang recognition by the PAZ domain and the 5′-phosphate recognition by the MID and PIWI domains of RISC. Herein, we report the synthesis of modified siRNAs containing terminal amide linkages by introducing hydroxyethylglycine PNA (hegPNA moieties at 5′, and at 3′ positions and on both terminals. Results of gene silencing studies highlight that some of these modifications are compatible with the RNAi machinery and markedly increase the resistance to serum-derived nucleases even after 24 h of incubation. Molecular docking simulations were attained to give at atomistic level a clearer picture of the effect of the most performing modifications on the interactions with the human Argonaute 2 PAZ, MID, and PIWI domains. This study adds another piece to the puzzle of the heterogeneous chemical modifications that can be attained to enhance the silencing efficiency of siRNAs.

  8. Emerging RNA-based drugs: siRNAs, microRNAs and derivates.

    Science.gov (United States)

    Pereira, Tiago Campos; Lopes-Cendes, Iscia

    2012-09-01

    An emerging new category of therapeutic agents based on ribonucleic acid has emerged and shown very promising in vitro, animal and pre-clinical results, known as small interfering RNAs (siRNAs), microRNAs mimics (miRNA mimics) and their derivates. siRNAs are small RNA molecules that promote potent and specific silencing of mutant, exogenous or aberrant genes through a mechanism known as RNA interference. These agents have called special attention to medicine since they have been used to experimentally treat a series of neurological conditions with distinct etiologies such as prion, viral, bacterial, fungal, genetic disorders and others. siRNAs have also been tested in other scenarios such as: control of anxiety, alcohol consumption, drug-receptor blockage and inhibition of pain signaling. Although in a much earlier stage, miRNAs mimics, anti-miRs and small activating RNAs (saRNAs) also promise novel therapeutic approaches to control gene expression. In this review we intend to introduce clinicians and medical researchers to the most recent advances in the world of siRNA- and miRNA-mediated gene control, its history, applications in cells, animals and humans, delivery methods (an yet unsolved hurdle), current status and possible applications in future clinical practice.

  9. Perivascular delivery of Notch 1 siRNA inhibits injury-induced arterial remodeling.

    Directory of Open Access Journals (Sweden)

    Eileen M Redmond

    Full Text Available To determine the efficacy of perivascular delivery of Notch 1 siRNA in preventing injury-induced arterial remodeling.Carotid artery ligation was performed to induce arterial remodeling. After 14 days, morphometric analysis confirmed increased vSMC growth and subsequent media thickening and neointimal formation. Laser capture microdissection, quantitative qRT-PCR and immunoblot analysis of medial tissue revealed a significant increase in Notch1 receptor and notch target gene, Hrt 1 and 2 expression in the injured vessels. Perivascular delivery of Notch 1 siRNA by pluronic gel inhibited the injury-induced increase in Notch 1 receptor and target gene expression when compared to scrambled siRNA controls while concomitantly reducing media thickening and neointimal formation to pre-injury, sham-operated levels. Selective Notch 1 knockdown also reversed the injury-induced inhibition of pro-apoptotic Bax expression while decreasing injury-induced anti-apoptotic Bcl-XL expression to sham-operated control levels. In parallel experiments, proliferative cyclin levels, as measured by PCNA expression, were reversed to sham-operated control levels following selective Notch 1 knockdown.These results suggest that injury-induced arterial remodeling can be successfully inhibited by localized perivascular delivery of Notch 1 siRNA.

  10. Novel targeted therapy for neuroblastoma: silencing the MXD3 gene using siRNA.

    Science.gov (United States)

    Duong, Connie; Yoshida, Sakiko; Chen, Cathy; Barisone, Gustavo; Diaz, Elva; Li, Yueju; Beckett, Laurel; Chung, Jong; Antony, Reuben; Nolta, Jan; Nitin, Nitin; Satake, Noriko

    2017-09-01

    BackgroundNeuroblastoma is the second most common extracranial cancer in children. Current therapies for neuroblastoma, which use a combination of chemotherapy drugs, have limitations for high-risk subtypes and can cause significant long-term adverse effects in young patients. Therefore, a new therapy is needed. In this study, we investigated the transcription factor MXD3 as a potential therapeutic target in neuroblastoma.MethodsMXD3 expression was analyzed in five neuroblastoma cell lines by immunocytochemistry and quantitative real-time reverse transcription PCR, and in 18 primary patient tumor samples by immunohistochemistry. We developed nanocomplexes using siRNA and superparamagnetic iron oxide nanoparticles to target MXD3 in neuroblastoma cell lines in vitro as a single-agent therapeutic and in combination with doxorubicin, vincristine, cisplatin, or maphosphamide-common drugs used in current neuroblastoma treatment.ResultsMXD3 was highly expressed in neuroblastoma cell lines and in patient tumors that had high-risk features. Neuroblastoma cells treated in vitro with the MXD3 siRNA nanocomplexes showed MXD3 protein knockdown and resulted in cell apoptosis. Furthermore, on combining MXD3 siRNA nanocomplexes with each of the four drugs, all showed additive efficacy.ConclusionThese results indicate that MXD3 is a potential new target and that the use of MXD3 siRNA nanocomplexes is a novel therapeutic approach for neuroblastoma.

  11. Inhibition of erythropoietin siRNA on corneal neovascularization of rabbit

    Directory of Open Access Journals (Sweden)

    Yu-Shun Xue

    2017-03-01

    Full Text Available AIM: To observe the expression of erythropoietin(EPOon the corneal of rabbit and evaluate the inhibition effect of EPO siRNA on corneal neovascularization(CNV. METHODS: Totally 22 healthy rabbits were randomly divided into 2 groups, which were experimental group and normal control group. Both eyes of rabbits in experimental group were chosen to establish corneal neovascularization model by alkali burn. The morphologic change of corneal was observed with slit lamp microscope and the area of CNV was calculated every day. After alkali burn, the right eye of the experimental group was accepted EPO siRNA injection under the conjunctiva, and the left eye was assigned to be experimental control group. The corneal with CNV was collected for immunohistochemistry at 3d, 7d, 14d, 21d after alkali burn, and the expression of EPO was measured. RESULTS: CNV began growing at the 3d after alkali burn in experimental group, and it was vigorous growing at 7d-14d period. The result of immunohistochemistry shows that the expression of EPO increased after the operation. Compared with experimental group, the rabbits who were treated by EPO siRNA was found with less neovascularization on their corneal, and the expression of EPO decreased. There were statistical significance between the two group at different time(PCONCLUSION: EPO is likely to play an important role on CNV growth, and EPO siRNA can inhibit the growth of CNV by restraining the expression of EPO.

  12. siRNA transfection in larvae of the barnacle Amphibalanus amphitrite

    KAUST Repository

    Zhang, G.; He, L.-S.; Wong, Y. H.; Yu, L.; Qian, P.-Y.

    2015-01-01

    RNA interference (RNAi) provides an efficient and specific technique for functional genomic studies. Yet, no successful application of RNAi has been reported in barnacles. In this study, siRNA against p38 MAPK was synthesized and then transfected into A. amphitrite larvae at either the nauplius or cyprid stage, or at both stages. Effects of siRNA transfection on the p38 MAPK level were hardly detectable in the cyprids when they were transfected at the nauplius stage. In contrast, larvae that were transfected at the cyprid stage showed lower levels of p38 MAPK than the blank and reagent controls. However, significantly decreased levels of phosphorylated p38 MAPK (pp38 MAPK) and reduced settlement rates were observed only in ‘double transfections’, in which larvae were exposed to siRNA solution at both the nauplius and cyprid stages. A relatively longer transfection time and more larval cells directly exposed to siRNA might explain the higher efficiency of double transfection experiments.

  13. Mechanistic profiling of the siRNA delivery dynamics of lipid-polymer hybrid nanoparticles.

    Science.gov (United States)

    Colombo, Stefano; Cun, Dongmei; Remaut, Katrien; Bunker, Matt; Zhang, Jianxin; Martin-Bertelsen, Birte; Yaghmur, Anan; Braeckmans, Kevin; Nielsen, Hanne M; Foged, Camilla

    2015-03-10

    Understanding the delivery dynamics of nucleic acid nanocarriers is fundamental to improve their design for therapeutic applications. We investigated the carrier structure-function relationship of lipid-polymer hybrid nanoparticles (LPNs) consisting of poly(DL-lactic-co-glycolic acid) (PLGA) nanocarriers modified with the cationic lipid dioleoyltrimethyl-ammoniumpropane (DOTAP). A library of siRNA-loaded LPNs was prepared by systematically varying the nitrogen-to-phosphate (N/P) ratio. Atomic force microscopy (AFM) and cryo-transmission electron microscopy (cryo-TEM) combined with small angle X-ray scattering (SAXS) and confocal laser scanning microscopy (CLSM) studies suggested that the siRNA-loaded LPNs are characterized by a core-shell structure consisting of a PLGA matrix core coated with lamellar DOTAP structures with siRNA localized both in the core and in the shell. Release studies in buffer and serum-containing medium combined with in vitro gene silencing and quantification of intracellular siRNA suggested that this self-assembling core-shell structure influences the siRNA release kinetics and the delivery dynamics. A main delivery mechanism appears to be mediated via the release of transfection-competent siRNA-DOTAP lipoplexes from the LPNs. Based on these results, we suggest a model for the nanostructural characteristics of the LPNs, in which the siRNA is organized in lamellar superficial assemblies and/or as complexes entrapped in the polymeric matrix. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Synthesis of Polymer-Lipid Nanoparticles by Microfluidic Focusing for siRNA Delivery

    Directory of Open Access Journals (Sweden)

    Yujing Li

    2016-10-01

    Full Text Available Polyethylenimine (PEI as a cationic polymer is commonly used as a carrier for gene delivery. PEI-800 is less toxic than PEI-25K but it is also less efficient. A novel nanocarrier was developed by combining PEI-800 with a pH-sensitive lipid to form polymer-lipid hybrid nanoparticles (P/LNPs. They were synthesized by microfluidic focusing (MF. Two microfluidic devices were used to synthesize P/LNPs loaded with VEGF siRNA. A series of P/LNPs with different particle sizes and distributions were obtained by altering the flow rate and geometry of microfluidic chips, and introducing sonication. Furthermore, the P/LNPs can be loaded with VEGF siRNA efficiently and were stable in serum for 12 h. Finally, P/LNPs produced by the microfluidic chip showed greater cellular uptake as well as down-regulation of VEGF protein level in both A549 and MCF-7 with reduced cellular toxicity. All in all, the P/LNPs produced by MF method were shown to be a safe and efficient carrier for VEGF siRNA, with potential application for siRNA therapeutics.

  15. Rational design of micro-RNA-like bifunctional siRNAs targeting HIV and the HIV coreceptor CCR5.

    Science.gov (United States)

    Ehsani, Ali; Saetrom, Pål; Zhang, Jane; Alluin, Jessica; Li, Haitang; Snøve, Ola; Aagaard, Lars; Rossi, John J

    2010-04-01

    Small-interfering RNAs (siRNAs) and micro-RNAs (miRNAs) are distinguished by their modes of action. SiRNAs serve as guides for sequence-specific cleavage of complementary mRNAs and the targets can be in coding or noncoding regions of the target transcripts. MiRNAs inhibit translation via partially complementary base-pairing to 3' untranslated regions (UTRs) and are generally ineffective when targeting coding regions of a transcript. In this study, we deliberately designed siRNAs that simultaneously direct cleavage and translational suppression of HIV RNAs, or cleavage of the mRNA encoding the HIV coreceptor CCR5 and suppression of translation of HIV. These bifunctional siRNAs trigger inhibition of HIV infection and replication in cell culture. The design principles have wide applications throughout the genome, as about 90% of genes harbor sites that make the design of bifunctional siRNAs possible.

  16. FcepsilonRI-alpha siRNA inhibits the antigen-induced activation of mast cells.

    Science.gov (United States)

    Safaralizadeh, Reza; Soheili, Zahra-Soheila; Deezagi, Abdolkhaleg; Pourpak, Zahra; Samiei, Shahram; Moin, Mostafa

    2009-12-01

    FcepsilonRI, The high affinity receptor for IgE plays a critical role in triggering the allergic reactions. It is responsible for inducing mast cell degranulation and deliberation of allergy mediators when it is aggregated by allergen and IgE complexes. FcepsilonRI on the mast cells consists of three subunits; alpha chain directly binds IgE, beta chain and dimmer of gamma chains together mediate intracellular signaling. Cross-linking of IgE-bound FcepsilonRI on the surface of mast cells and basophils by the multivalent antigen induces release of chemical mediators. The present in vitro study was designed to investigate the effect of synthetic FcepsilonRI-alpha siRNA on the antigen-induced activation of MC/9 cells. MC/9 cells which are murine mast cells were transfected by FcepsilonRI-alpha siRNA and negative control siRNA. After 6 h, anti-DNP (Dinitrophenyl) IgE was used for the cells sensitization. Then the cells were challenged with Dinitrophenyl-Human Serum Albumin (DNP-HSA) for mast cell degranulation induction before collection of supernatants. The amount of mRNA and protein expression was measured by Real Time PCR and western blot analysis, respectively. Determination of the expression rate of FcepsilonRI-alpha on cell surface was achieved by flow cytometry. ELISA and spectrophotometry methods were used subsequently for measuring the effects of FcepsilonRI-alpha siRNA on antigen-induced histamine and beta-hexosaminidase release. FcepsilonRI-alpha siRNA treated cells showed significant decrease in FcepsilonRI-alpha mRNA and protein expression in comparison to control cells. FcepsilonRI-mediated mast cell release of beta-hexosaminidase and histamine were also inhibited. In this study it was shown that FcepsilonRI-alpha siRNA could suppress FcepsilonRI-alpha expression and inhibited degranulation and histamine release in antigen-stimulated MC/9 cells. In conclusion, knock-down of FcepsilonRI-alpha by siRNA could be a promising method for inhibition of the mast

  17. The antifibrotic effects of TGF-{beta}1 siRNA on hepatic fibrosis in rats

    Energy Technology Data Exchange (ETDEWEB)

    Lang, Qing; Liu, Qi [Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Instituted for Virus Hepatitis and Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing (China); Xu, Ning [The Second Hospital of YuLin, Shanxi Province (China); Qian, Ke-Li; Qi, Jing-Hu; Sun, Yin-Chun; Xiao, Lang [Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Instituted for Virus Hepatitis and Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing (China); Shi, Xiao-Feng, E-mail: sxff2003@yahoo.com.cn [Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Instituted for Virus Hepatitis and Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing (China)

    2011-06-10

    Highlights: {yields} We constructed CCL4 induced liver fibrosis model successfully. {yields} We proofed that the TGF-{beta}1 siRNA had a definite therapy effect to CCL4 induced liver fibrosis. {yields} The therapy effect of TGF-{beta}1 siRNA had dose-dependent. -- Abstract: Background/aims: Hepatic fibrosis results from the excessive secretion of matrix proteins by hepatic stellate cells (HSCs), which proliferate during fibrotic liver injury. Transforming growth factor (TGF)-{beta}1 is the dominant stimulus for extracellular matrix (ECM) production by stellate cells. Our study was designed to investigate the antifibrotic effects of using short interference RNA (siRNA) to target TGF-{beta}1 in hepatic fibrosis and its mechanism in rats exposed to a high-fat diet and carbon tetrachloride (CCL4). Methods: A total of 40 healthy, male SD (Sprague-Dawley) rats were randomly divided into five even groups containing of eight rats each: normal group, model group, TGF-{beta}1 siRNA 0.125 mg/kg treatment group, TGF-{beta}1 siRNA 0.25 mg/kg treatment group and TGF-{beta}1 siRNA negative control group (0.25 mg/kg). CCL4 and a high-fat diet were used for 8 weeks to induce hepatic fibrosis. All the rats were then sacrificed to collect liver tissue samples. A portion of the liver samples were soaked in formalin for Hematoxylin-Eosin staining, classifying the degree of liver fibrosis, and detecting the expression of type I and III collagen and TGF-{beta}1; the remaining liver samples were stored in liquid nitrogen to be used for detecting TGF-{beta}1 by Western blotting and for measuring the mRNA expression of type I and III collagen and TGF-{beta}1 by quantitative real-time polymerase chain reaction. Results: Comparing the TGF-{beta}1 siRNA 0.25 mg/kg treatment group to the model group, the TGF-{beta}1 siRNA negative control group and the TGF-{beta}1 siRNA 0.125 mg/kg treatment group showed significantly reduced levels of pathological changes, protein expression and the m

  18. The antifibrotic effects of TGF-β1 siRNA on hepatic fibrosis in rats

    International Nuclear Information System (INIS)

    Lang, Qing; Liu, Qi; Xu, Ning; Qian, Ke-Li; Qi, Jing-Hu; Sun, Yin-Chun; Xiao, Lang; Shi, Xiao-Feng

    2011-01-01

    Highlights: → We constructed CCL4 induced liver fibrosis model successfully. → We proofed that the TGF-β1 siRNA had a definite therapy effect to CCL4 induced liver fibrosis. → The therapy effect of TGF-β1 siRNA had dose-dependent. -- Abstract: Background/aims: Hepatic fibrosis results from the excessive secretion of matrix proteins by hepatic stellate cells (HSCs), which proliferate during fibrotic liver injury. Transforming growth factor (TGF)-β1 is the dominant stimulus for extracellular matrix (ECM) production by stellate cells. Our study was designed to investigate the antifibrotic effects of using short interference RNA (siRNA) to target TGF-β1 in hepatic fibrosis and its mechanism in rats exposed to a high-fat diet and carbon tetrachloride (CCL4). Methods: A total of 40 healthy, male SD (Sprague-Dawley) rats were randomly divided into five even groups containing of eight rats each: normal group, model group, TGF-β1 siRNA 0.125 mg/kg treatment group, TGF-β1 siRNA 0.25 mg/kg treatment group and TGF-β1 siRNA negative control group (0.25 mg/kg). CCL4 and a high-fat diet were used for 8 weeks to induce hepatic fibrosis. All the rats were then sacrificed to collect liver tissue samples. A portion of the liver samples were soaked in formalin for Hematoxylin-Eosin staining, classifying the degree of liver fibrosis, and detecting the expression of type I and III collagen and TGF-β1; the remaining liver samples were stored in liquid nitrogen to be used for detecting TGF-β1 by Western blotting and for measuring the mRNA expression of type I and III collagen and TGF-β1 by quantitative real-time polymerase chain reaction. Results: Comparing the TGF-β1 siRNA 0.25 mg/kg treatment group to the model group, the TGF-β1 siRNA negative control group and the TGF-β1 siRNA 0.125 mg/kg treatment group showed significantly reduced levels of pathological changes, protein expression and the mRNA expression of TGF-β1, type I collagen and type III collagen (P < 0

  19. Intensification of oily waste waters purification by means of liquid atomization

    Science.gov (United States)

    Eskin, A. A.; Tkach, N. S.; Kim, M. I.; Zakharov, G. A.

    2017-10-01

    In this research, a possibility of using liquid atomization for improving the efficiency of purification of wastewater by different methods has been studied. By the introduced method and an experimental setup for wastewater purification, saturation rate increases with its purification by means of dissolved air flotation. Liquid atomization under excess pressure allows to gain a large interfacial area between the saturated liquid and air, which may increase the rate of purified liquid saturation almost twice, compared to the existing methods of saturation. Current disadvantages of liquid atomization used for intensification of wastewater purification include high energy cost and secondary emulsion of polluting agents. It is also known that by means of liquid atomization a process of ozonizing can be intensified. Large contact surface between the purified liquid and ozone-air mixture increases the oxidizing efficiency, which allows to diminish ozone discharge. Liquid atomization may be used for purification of wastewaters by ultraviolet radiation. Small drops of liquid will be proportionally treated by ultraviolet, which makes it possible to do purification even of turbid wastewaters. High-speed liquid motion will prevent the pollution of quartz tubes of ultraviolet lamps.

  20. Targeted transfection increases siRNA uptake and gene silencing of primary endothelial cells in vitro--a quantitative study.

    Science.gov (United States)

    Asgeirsdóttir, Sigridur A; Talman, Eduard G; de Graaf, Inge A; Kamps, Jan A A M; Satchell, Simon C; Mathieson, Peter W; Ruiters, Marcel H J; Molema, Grietje

    2010-01-25

    Applications of small-interfering RNA (siRNA) call for specific and efficient delivery of siRNA into particular cell types. We developed a novel, non-viral targeting system to deliver siRNA specifically into inflammation-activated endothelial cells. This was achieved by conjugating the cationic amphiphilic lipid SAINT to antibodies recognizing the inflammatory cell adhesion molecule E-selectin. These anti-E-selectin-SAINT lipoplexes (SAINTarg) maintained antigen recognition capacity of the parental antibody in vitro, and ex vivo in human kidney tissue slices subjected to inflammatory conditions. Regular SAINT mediated transfection resulted in efficient gene silencing in human microvascular endothelial cells (HMEC-1) and conditionally immortalized glomerular endothelial cells (ciGEnC). However, primary human umbilical vein endothelial cells (HUVEC) transfected poorly, a phenomenon that we could quantitatively correlate with a cell-type specific capacity to facilitate siRNA uptake. Importantly, SAINTarg increased siRNA uptake and transfection specificity for activated endothelial cells. Transfection with SAINTarg delivered significantly more siRNA into activated HUVEC, compared to transfection with non-targeted SAINT. The enhanced uptake of siRNA was corroborated by improved silencing of both gene- and protein expression of VE-cadherin in activated HUVEC, indicating that SAINTarg delivered functionally active siRNA into endothelial cells. The obtained results demonstrate a successful design of a small nucleotide carrier system with improved and specific siRNA delivery into otherwise difficult-to-transfect primary endothelial cells, which in addition reduced considerably the amount of siRNA needed for gene silencing. Copyright 2009 Elsevier B.V. All rights reserved.

  1. Smart polymeric nanoparticles with pH-responsive and PEG-detachable properties for co-delivering paclitaxel and survivin siRNA to enhance antitumor outcomes.

    Science.gov (United States)

    Jin, Mingji; Jin, Guangming; Kang, Lin; Chen, Liqing; Gao, Zhonggao; Huang, Wei

    2018-01-01

    The co-delivery of chemotherapeutic agents and small interfering RNA (siRNA) within one cargo can enhance the anticancer outcomes through its synergistic therapeutic effects. We prepared smart polymeric nanoparticles (NPs) with pH-responsive and poly(ethylene glycol) (PEG)-detachable properties to systemically co-deliver paclitaxel (PTX) and siRNA against survivin gene for lung cancer therapy. The cationic polyethyleneimine-block-polylactic acid (PEI-PLA) was first synthesized and characterized, with good biocompatibility. PTX was encapsulated into the hydrophobic core of the PEI-PLA polymers by dialysis, and then the survivin siRNA was loaded onto the PTX-loaded NPs (PEI-PLA/PTX) through electrostatic interaction between siRNA and PEI block. Finally, the negatively charged poly(ethylene glycol)-block-poly(L-aspartic acid sodium salt) (PEG-PAsp) was coated onto the surface of NPs by electrostatic interaction to form final smart polymeric NPs with mean particle size of 82.4 nm and zeta potential of 4.1 mV. After uptake of NPs by tumor cells, the PEG-PAsp segments became electrically neutral owing to the lower endosome pH and consequently detached from the smart NPs. This process allowed endosomal escape of the NPs through the proton-sponge effect of the exposed PEI moiety. The resulting NPs achieved drug loading of 6.04 wt% and exhibited good dispersibility within 24 h in 10% fetal bovine serum (FBS). At pH 5.5, the NPs presented better drug release and cellular uptake than at pH 7.4. The NPs with survivin siRNA effectively knocked down the expression of survivin mRNA and protein owing to enhanced cell uptake of NPs. Cell counting kit-8 (CCK-8) assay showed that the NPs presented low systemic toxicity and improved antiproliferation effect of PTX on A549 cells. Moreover, in vivo studies demonstrated that accumulated NPs in the tumor site were capable of inhibiting the tumor growth and extending the survival rate of the mice by silencing the survivin gene and

  2. Filters for water purification from radionuclides

    International Nuclear Information System (INIS)

    Mironov, V.V.; Khaydarov, R.R.; Khaydarov, R.A.; Gapurova, O.U.

    2006-01-01

    Full text: At present purification of waste water and drinking water from radionuclides, heavy metal ions, and organic contaminants is one of the most important problems. One of widely used methods for solving this problem is the ion exchange method based on using of different types of resins and fibroid sorbents. This paper deals with new chemically modified polyester fibroid filters having satisfactory adsorption characteristics. The process of the filter production includes their treatment by acrylonitrilic emulsion for improving mechanical characteristics. An advantage of the fibroid ion-exchange sorbents over resin is in their high sorption rate, effective regeneration and small value of pressure drop of the sorbent layer for purified water. The specific surface of the fibroid sorbents is (2 - 3). 10 4 m 2 / kg, i.e. about 10 2 times greater than that of the resin (10 2 m 2 / kg). Owing to that fact the rate of the sorption process on the developed fibroid sorbents is much greater than that on the resin. The developed cation- and anion-exchange filters can be used for removing metal ions (Zn, Ni, Cu, Sb, Co, Cd, Cr, etc.) and organic compounds (M- 32 P, M- 131 I, M- 99 Mo+ 99m Tc, etc.) from water. Capacity of the cation-exchange sorbents is 0.25 meq/g (Cu 2+ ) and that of the anion - exchange is 0.45 meq/g (Cr 6+ ). The cation- and anion-exchange filters are also selective for removing radionuclides 134 , 137 Cs, 90 Sr, 60 Co and 129 I in presence of Na + , K + , Ca 2+ , Mg 2+ , Cl - ions in water at concentrations up to 500 mg/L. New developed ion-exchange sorbents have been used in drinking water filters and mini-systems for removing organic and inorganic contaminants, in the equipment for waste water purification from oil products (at atomic power stations, car-washing stations, etc), from heavy metal ions (in electronic industry, match fabrics, leather processing plants etc). (author)

  3. Chemosensitization of cancer cells by siRNA using targeted nanogel delivery

    International Nuclear Information System (INIS)

    Dickerson, Erin B; Blackburn, William H; Smith, Michael H; Kapa, Laura B; Lyon, L Andrew; McDonald, John F

    2010-01-01

    Chemoresistance is a major obstacle in cancer treatment. Targeted therapies that enhance cancer cell sensitivity to chemotherapeutic agents have the potential to increase drug efficacy while reducing toxic effects on untargeted cells. Targeted cancer therapy by RNA interference (RNAi) is a relatively new approach that can be used to reversibly silence genes in vivo by selectively targeting genes such as the epidermal growth factor receptor (EGFR), which has been shown to increase the sensitivity of cancer cells to taxane chemotherapy. However, delivery represents the main hurdle for the broad development of RNAi therapeutics. We report here the use of core/shell hydrogel nanoparticles (nanogels) functionalized with peptides that specially target the EphA2 receptor to deliver small interfering RNAs (siRNAs) targeting EGFR. Expression of EGFR was determined by immunoblotting, and the effect of decreased EGFR expression on chemosensitization of ovarian cancer cells after siRNA delivery was investigated. Treatment of EphA2 positive Hey cells with siRNA-loaded, peptide-targeted nanogels decreased EGFR expression levels and significantly increased the sensitivity of this cell line to docetaxel (P < 0.05). Nanogel treatment of SK-OV-3 cells, which are negative for EphA2 expression, failed to reduce EGFR levels and did not increase docetaxel sensitivity (P > 0.05). This study suggests that targeted delivery of siRNAs by nanogels may be a promising strategy to increase the efficacy of chemotherapy drugs for the treatment of ovarian cancer. In addition, EphA2 is a viable target for therapeutic delivery, and the siRNAs are effectively protected by the nanogel carrier, overcoming the poor stability and uptake that has hindered clinical advancement of therapeutic siRNAs

  4. Viral RNAi suppressor reversibly binds siRNA to outcompete Dicer and RISC via multiple turnover.

    Science.gov (United States)

    Rawlings, Renata A; Krishnan, Vishalakshi; Walter, Nils G

    2011-04-29

    RNA interference is a conserved gene regulatory mechanism employed by most eukaryotes as a key component of their innate immune response to viruses and retrotransposons. During viral infection, the RNase-III-type endonuclease Dicer cleaves viral double-stranded RNA into small interfering RNAs (siRNAs) 21-24 nucleotides in length and helps load them into the RNA-induced silencing complex (RISC) to guide the cleavage of complementary viral RNA. As a countermeasure, many viruses have evolved viral RNA silencing suppressors (RSS) that tightly, and presumably quantitatively, bind siRNAs to thwart RNA-interference-mediated degradation. Viral RSS proteins also act across kingdoms as potential immunosuppressors in gene therapeutic applications. Here we report fluorescence quenching and electrophoretic mobility shift assays that probe siRNA binding by the dimeric RSS p19 from Carnation Italian Ringspot Virus, as well as by human Dicer and RISC assembly complexes. We find that the siRNA:p19 interaction is readily reversible, characterized by rapid binding [(1.69 ± 0.07) × 10(8) M(-)(1) s(-1)] and marked dissociation (k(off)=0.062 ± 0.002 s(-1)). We also observe that p19 efficiently competes with recombinant Dicer and inhibits the formation of RISC-related assembly complexes found in human cell extract. Computational modeling based on these results provides evidence for the transient formation of a ternary complex between siRNA, human Dicer, and p19. An expanded model of RNA silencing indicates that multiple turnover by reversible binding of siRNAs potentiates the efficiency of the suppressor protein. Our predictive model is expected to be applicable to the dosing of p19 as a silencing suppressor in viral gene therapy. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Addressing the medicinal chemistry bottleneck: a lean approach to centralized purification.

    Science.gov (United States)

    Weller, Harold N; Nirschl, David S; Paulson, James L; Hoffman, Steven L; Bullock, William H

    2012-09-10

    The use of standardized lean manufacturing principles to improve drug discovery productivity is often thought to be at odds with fostering innovation. This manuscript describes how selective implementation of a lean optimized process, in this case centralized purification for medicinal chemistry, can improve operational productivity and increase scientist time available for innovation. A description of the centralized purification process is provided along with both operational and impact (productivity) metrics, which indicate lower cost, higher output, and presumably more free time for innovation as a result of the process changes described.

  6. Soft computing model for optimized siRNA design by identifying off target possibilities using artificial neural network model.

    Science.gov (United States)

    Murali, Reena; John, Philips George; Peter S, David

    2015-05-15

    The ability of small interfering RNA (siRNA) to do posttranscriptional gene regulation by knocking down targeted genes is an important research topic in functional genomics, biomedical research and in cancer therapeutics. Many tools had been developed to design exogenous siRNA with high experimental inhibition. Even though considerable amount of work has been done in designing exogenous siRNA, design of effective siRNA sequences is still a challenging work because the target mRNAs must be selected such that their corresponding siRNAs are likely to be efficient against that target and unlikely to accidentally silence other transcripts due to sequence similarity. In some cases, siRNAs may tolerate mismatches with the target mRNA, but knockdown of genes other than the intended target could make serious consequences. Hence to design siRNAs, two important concepts must be considered: the ability in knocking down target genes and the off target possibility on any nontarget genes. So before doing gene silencing by siRNAs, it is essential to analyze their off target effects in addition to their inhibition efficacy against a particular target. Only a few methods have been developed by considering both efficacy and off target possibility of siRNA against a gene. In this paper we present a new design of neural network model with whole stacking energy (ΔG) that enables to identify the efficacy and off target effect of siRNAs against target genes. The tool lists all siRNAs against a particular target with their inhibition efficacy and number of matches or sequence similarity with other genes in the database. We could achieve an excellent performance of Pearson Correlation Coefficient (R=0. 74) and Area Under Curve (AUC=0.906) when the threshold of whole stacking energy is ≥-34.6 kcal/mol. To the best of the author's knowledge, this is one of the best score while considering the "combined efficacy and off target possibility" of siRNA for silencing a gene. The proposed model

  7. Delivery of kinesin spindle protein targeting siRNA in solid lipid nanoparticles to cellular models of tumor vasculature

    International Nuclear Information System (INIS)

    Ying, Bo; Campbell, Robert B.

    2014-01-01

    Highlights: • siRNA-lipid nanoparticles are solid particles not lipid bilayers with aqueous core. • High, but not low, PEG content can prevent nanoparticle encapsulation of siRNA. • PEG reduces cellular toxicity of cationic nanoparticles in vitro. • PEG reduces zeta potential while improving gene silencing of siRNA nanoparticles. • Kinesin spindle protein can be an effective target for tumor vascular targeting. - Abstract: The ideal siRNA delivery system should selectively deliver the construct to the target cell, avoid enzymatic degradation, and evade uptake by phagocytes. In the present study, we evaluated the importance of polyethylene glycol (PEG) on lipid-based carrier systems for encapsulating, and delivering, siRNA to tumor vessels using cellular models. Lipid nanoparticles containing different percentage of PEG were evaluated based on their physical chemical properties, density compared to water, siRNA encapsulation, toxicity, targeting efficiency and gene silencing in vitro. siRNA can be efficiently loaded into lipid nanoparticles (LNPs) when DOTAP is included in the formulation mixture. However, the total amount encapsulated decreased with increase in PEG content. In the presence of siRNA, the final formulations contained a mixed population of particles based on density. The major population which contains the majority of siRNA exhibited a density of 4% glucose, and the minor fraction associated with a decreased amount of siRNA had a density less than PBS. The inclusion of 10 mol% PEG resulted in a greater amount of siRNA associated with the minor fraction. Finally, when kinesin spindle protein (KSP) siRNA was encapsulated in lipid nanoparticles containing a modest amount of PEG, the proliferation of endothelial cells was inhibited due to the efficient knock down of KSP mRNA. The presence of siRNA resulted in the formation of solid lipid nanoparticles when prepared using the thin film and hydration method. LNPs with a relatively modest amount of

  8. Recent developments in water purification technology

    International Nuclear Information System (INIS)

    Shah, G.C.

    2000-01-01

    Water is source of life. More than 70% surface of earth is covered with water. Water is extensively used in industries for various purposes like cooling, rinsing, steam generation and as process fluid etc. Water as found in nature cannot be used directly in industries since it contains various types of impurities which can affect smooth operation of equipment/plants. Quality of water requirement for industry greatly differs from the quality requirement for domestic use. Some industrial plant such as nuclear and thermal power plants, pharmaceutical plants and electronic industries require water of quality approaching that of ultra pure water. To get water of required quality from available natural resources, selection of proper treatment methods and control of necessary water conditioning procedures are essential analysis of water for different types of impurities involving various analytical techniques is also of great importance to select proper processes for its purification. In this talk, a survey of various types of impurities present in water from different sources, their harmful effects and general methods than can be used for removal of these impurities are detailed. Various methods of removing suspended and colloidal impurities, organic and gaseous impurities from water are also described

  9. Investigation of Various LiCl Waste Salt Purification Technologies

    International Nuclear Information System (INIS)

    Yung-Zun Cho; Hee-Chul Yang; Han-Soo Lee; In-Tae Kim

    2008-01-01

    Various purification research of LiCl waste molten salt generated from electroreduction process were tested. The purification of the LiCl waste salt very important in a various aspects, where the purification means separation of cesium and strontium form LiCl salt melts. In this study, for the separation of cesium and strontium from LiCl salt melts, precipitant agent addition techniques such as sulfate and carbonate addition method and, as a new attempt, zone freezing technique for concentration of cesium and strontium elements was investigated. As a results of this research, only strontium was carbonated by reaction with Li 2 CO 3 (cesium did not react with Li 2 CO 3 ). In case of sulfate addition method, both cesium and strontium were converted into their sulfate that is Cs 2 S 2 O 6 and SrSO 4 and maximum sulfate efficiency of cesium and strontium were about 72% and 95%, respectively. Cesium and strontium involved in LiCl molten salt could be concentrated in the molten salt by using zone freezing method. (authors)

  10. Affinity purification of recombinant human plasminogen activator ...

    African Journals Online (AJOL)

    Affinity purification of recombinant human plasminogen activator from ... Screening antibody was performed using rhPA milk in an ELISA-elution assay. ... useful for purifying other tPA mutants or other novel recombinant milkderived proteins.

  11. Purification, characterization of phytase enzyme from Lactobacillus ...

    African Journals Online (AJOL)

    SAM

    2014-06-04

    Jun 4, 2014 ... 2Department of Food Technology, Erzurum Vocational Training School, Ataturk University, 25240, ... facultative anaerobic, catalase-negative, immobile (with ..... Partial purification of phytase from a soil isolate bacterium,.

  12. Purification and Characterization of Thermostable Cellulase from ...

    African Journals Online (AJOL)

    Available online at http://www.tjpr.org ... Methods: Molecular community structure of the newly selected thermophilic bacterial ... Keywords: Thermostable cellulase, Sugarcane bagasse, Purification, Characterization, Hot spring ... Currently, one.

  13. Membrane Purification Cell for Aluminum Recycling

    Energy Technology Data Exchange (ETDEWEB)

    David DeYoung; James Wiswall; Cong Wang

    2011-11-29

    Recycling mixed aluminum scrap usually requires adding primary aluminum to the scrap stream as a diluent to reduce the concentration of non-aluminum constituents used in aluminum alloys. Since primary aluminum production requires approximately 10 times more energy than melting scrap, the bulk of the energy and carbon dioxide emissions for recycling are associated with using primary aluminum as a diluent. Eliminating the need for using primary aluminum as a diluent would dramatically reduce energy requirements, decrease carbon dioxide emissions, and increase scrap utilization in recycling. Electrorefining can be used to extract pure aluminum from mixed scrap. Some example applications include producing primary grade aluminum from specific scrap streams such as consumer packaging and mixed alloy saw chips, and recycling multi-alloy products such as brazing sheet. Electrorefining can also be used to extract valuable alloying elements such as Li from Al-Li mixed scrap. This project was aimed at developing an electrorefining process for purifying aluminum to reduce energy consumption and emissions by 75% compared to conventional technology. An electrolytic molten aluminum purification process, utilizing a horizontal membrane cell anode, was designed, constructed, operated and validated. The electrorefining technology could also be used to produce ultra-high purity aluminum for advanced materials applications. The technical objectives for this project were to: - Validate the membrane cell concept with a lab-scale electrorefining cell; - Determine if previously identified voltage increase issue for chloride electrolytes holds for a fluoride-based electrolyte system; - Assess the probability that voltage change issues can be solved; and - Conduct a market and economic analysis to assess commercial feasibility. The process was tested using three different binary alloy compositions (Al-2.0 wt.% Cu, Al-4.7 wt.% Si, Al-0.6 wt.% Fe) and a brazing sheet scrap composition (Al-2

  14. Multipartite electronic entanglement purification with charge detection

    Energy Technology Data Exchange (ETDEWEB)

    Sheng Yubo [Department of Physics, Tsinghua University, Beijing 100084 (China); Deng, Fu-Guo [Department of Physics, Beijing Normal University, Beijing 100875 (China); Long Guilu, E-mail: gllong@tsinghua.edu.c [Department of Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory for Atomic and Molecular NanoSciences, Tsinghua University, Beijing 100084 (China); Tsinghua National Laboratory for Information Science and Technology, Beijing 100084 (China)

    2011-01-17

    We present a multipartite entanglement purification scheme in a Greenberger-Horne-Zeilinger state for electrons based on their spins and their charges. This scheme works for purification with two steps, i.e., bit-flip error correction and phase-flip error correction. By repeating these two steps, the parties in quantum communication can get some high-fidelity multipartite entangled electronic systems.

  15. Recovering of thorium contained in wastes from Thorium Purification Plant

    International Nuclear Information System (INIS)

    Brandao Filho, D.; Hespanhol, E.C.B.; Baba, S.; Miranda, L.E.T.; Araujo, J.A. de.

    1992-08-01

    A study has been developed in order to establish a chemical process for recovering thorium from wastes produced at the Thorium Purification Plant of the Instituto de Pesquisas Energeticas e Nucleares. The recovery of thorium in this process will be made by means of solvent extraction technique. Solutions of TBP/Varsol were employed as extracting agent during the runs. The influence of thorium concentration in the solution, aqueous phase acidity, volume ratio of the phases, percentage of TBP/Varsol and the contact time of the phases on the extraction of thorium and lanthanides was determined. (author)

  16. Recovery and purification of americium from molten salt extraction residues

    International Nuclear Information System (INIS)

    Navratil, J.D.; Martella, L.L.; Thompson, G.H.

    1980-01-01

    Americium recovery and purification development at Rocky Flats involves the testing of a combined anion exchange - bidentate organophosphorus liquid - liquid extraction or extraction chromatography process for separating americium from molten salt extraction residues. Laboratory-scale and preliminary pilot-plant results have shown that americium can be effectively recovered and purified from impurity elements such as aluminum, calcium, magnesium, plutonium, potassium, sodium, and zinc. The purified americium oxide product from the liquid - liquid extraction process contained greater than 95% AmO 2 with less than 1% of any individual impurity element

  17. Development of Gold Nanoparticle towards Radioenhancement Therapy, Renal Clearance, siRNA Delivery and Light-Controlled Gene Silencing

    Science.gov (United States)

    Wang, Jianxin

    Gold nanoparticles (GNPs) have been widely studied and used in research for diagnostic, prophylactic or therapeutic purposes. However, they still face many technical challenges before they can be used to effectively address unmet biomedical needs. The theme of this dissertation is focused on addressing challenges of GNPs in clinical translation, and to improve their potential for application in radioenhancement therapy and siRNA delivery. We demonstrate the facile self-assembly of micellar gold nanocapsules using zwitterionic surfactants, with hydrodynamic diameters below 10 nm, which holds promise for good renal clearance to promote the excretion of GNPs in human body. We also prepared PEI- and PEG-coated GNPs and demonstrated their uptake into HeLa cells with exposure to soft X-rays (120 kVp), based on the consideration that the proximity of GNPs to nuclear DNA may be beneficial for enhancing low-energy ionizing radiotherapy. GNP-mediated siRNA delivery may be challenged by nonspecific siRNA desorption during circulation, which can cause off-target effects and immunogenicity. The use of gold nanorods (GNRs) for siRNA delivery also faces challenges like reduced dispersion stability during siRNA functionalization. We developed an effective way to load siRNA onto GNRs at high density, using oleylsulfobetaine (OSB) as an intermediate surfactant and dithiocarbamates (DTCs) as desorption-resistant anchors for siRNA. The GNR?siRNA complexes provided excellent control for laser-triggered gene silencing.

  18. In Silico, In Vitro, and In Vivo Studies Indicate the Potential Use of Bolaamphiphiles for Therapeutic siRNAs Delivery

    Directory of Open Access Journals (Sweden)

    Taejin Kim

    2013-01-01

    Full Text Available Specific small interfering RNAs (siRNAs designed to silence different oncogenic pathways can be used for cancer therapy. However, non-modified naked siRNAs have short half-lives in blood serum and encounter difficulties in crossing biological membranes due to their negative charge. These obstacles can be overcome by using siRNAs complexed with bolaamphiphiles, consisting of two positively charged head groups that flank an internal hydrophobic chain. Bolaamphiphiles have relatively low toxicities, long persistence in the blood stream, and most importantly, in aqueous conditions can form poly-cationic micelles thus, becoming amenable to association with siRNAs. Herein, two different bolaamphiphiles with acetylcholine head groups attached to an alkyl chain in two distinct configurations are compared for their abilities to complex with siRNAs and deliver them into cells inducing gene silencing. Our explicit solvent molecular dynamics (MD simulations showed that bolaamphiphiles associate with siRNAs due to electrostatic, hydrogen bonding, and hydrophobic interactions. These in silico studies are supported by various in vitro and in cell culture experimental techniques as well as by some in vivo studies. Results demonstrate that depending on the application, the extent of siRNA chemical protection, delivery efficiency, and further intracellular release can be varied by simply changing the type of bolaamphiphile used.

  19. Site-Specific Modification Using the 2′-Methoxyethyl Group Improves the Specificity and Activity of siRNAs

    Directory of Open Access Journals (Sweden)

    Xinyun Song

    2017-12-01

    Full Text Available Rapid progress has been made toward small interfering RNA (siRNA-based therapy for human disorders, but rationally optimizing siRNAs for high specificity and potent silencing remains a challenge. In this study, we explored the effect of chemical modification at the cleavage site of siRNAs. We found that modifications at positions 9 and 10 markedly reduced the silencing potency of the unmodified strand of siRNAs but were well tolerated by the modified strand. Intriguingly, addition of the 2′-methoxyethyl (MOE group at the cleavage site improved both the specificity and silencing activity of siRNAs by facilitating the oriented RNA-induced silencing complex (RISC loading of the modified strand. Furthermore, we combined MOE modifications at positions 9 and 10 of one strand together with 2′-O-methylation (OMe at position 14 of the other strand and found a synergistic effect that improved the specificity of siRNAs. The surprisingly beneficial effect of the combined modification was validated using siRNA-targeting endogenous gene intercellular adhesion molecule 1 (ICAM1. We found that the combined modifications eliminated its off-target effects. In conclusion, we established effective strategies to optimize siRNAs using site-specific MOE modifications. The findings may allow the creation of superior siRNAs for therapy in terms of activity and specificity.

  20. A genome-wide siRNA screen to identify modulators of insulin sensitivity and gluconeogenesis.

    Directory of Open Access Journals (Sweden)

    Ruojing Yang

    Full Text Available BACKGROUND: Hepatic insulin resistance impairs insulin's ability to suppress hepatic glucose production (HGP and contributes to the development of type 2 diabetes (T2D. Although the interests to discover novel genes that modulate insulin sensitivity and HGP are high, it remains challenging to have a human cell based system to identify novel genes. METHODOLOGY/PRINCIPAL FINDINGS: To identify genes that modulate hepatic insulin signaling and HGP, we generated a human cell line stably expressing beta-lactamase under the control of the human glucose-6-phosphatase (G6PC promoter (AH-G6PC cells. Both beta-lactamase activity and endogenous G6PC mRNA were increased in AH-G6PC cells by a combination of dexamethasone and pCPT-cAMP, and reduced by insulin. A 4-gene High-Throughput-Genomics assay was developed to concomitantly measure G6PC and pyruvate-dehydrogenase-kinase-4 (PDK4 mRNA levels. Using this assay, we screened an siRNA library containing pooled siRNA targeting 6650 druggable genes and identified 614 hits that lowered G6PC expression without increasing PDK4 mRNA levels. Pathway analysis indicated that siRNA-mediated knockdown (KD of genes known to positively or negatively affect insulin signaling increased or decreased G6PC mRNA expression, respectively, thus validating our screening platform. A subset of 270 primary screen hits was selected and 149 hits were confirmed by target gene KD by pooled siRNA and 7 single siRNA for each gene to reduce G6PC expression in 4-gene HTG assay. Subsequently, pooled siRNA KD of 113 genes decreased PEPCK and/or PGC1alpha mRNA expression thereby demonstrating their role in regulating key gluconeogenic genes in addition to G6PC. Last, KD of 61 of the above 113 genes potentiated insulin-stimulated Akt phosphorylation, suggesting that they suppress gluconeogenic gene by enhancing insulin signaling. CONCLUSIONS/SIGNIFICANCE: These results support the proposition that the proteins encoded by the genes identified in

  1. Precise engineering of siRNA delivery vehicles to tumors using polyion complexes and gold nanoparticles.

    Science.gov (United States)

    Kim, Hyun Jin; Takemoto, Hiroyasu; Yi, Yu; Zheng, Meng; Maeda, Yoshinori; Chaya, Hiroyuki; Hayashi, Kotaro; Mi, Peng; Pittella, Frederico; Christie, R James; Toh, Kazuko; Matsumoto, Yu; Nishiyama, Nobuhiro; Miyata, Kanjiro; Kataoka, Kazunori

    2014-09-23

    For systemic delivery of siRNA to solid tumors, a size-regulated and reversibly stabilized nanoarchitecture was constructed by using a 20 kDa siRNA-loaded unimer polyion complex (uPIC) and 20 nm gold nanoparticle (AuNP). The uPIC was selectively prepared by charge-matched polyionic complexation of a poly(ethylene glycol)-b-poly(L-lysine) (PEG-PLL) copolymer bearing ∼40 positive charges (and thiol group at the ω-end) with a single siRNA bearing 40 negative charges. The thiol group at the ω-end of PEG-PLL further enabled successful conjugation of the uPICs onto the single AuNP through coordinate bonding, generating a nanoarchitecture (uPIC-AuNP) with a size of 38 nm and a narrow size distribution. In contrast, mixing thiolated PEG-PLLs and AuNPs produced a large aggregate in the absence of siRNA, suggesting the essential role of the preformed uPIC in the formation of nanoarchitecture. The smart uPIC-AuNPs were stable in serum-containing media and more resistant against heparin-induced counter polyanion exchange, compared to uPICs alone. On the other hand, the treatment of uPIC-AuNPs with an intracellular concentration of glutathione substantially compromised their stability and triggered the release of siRNA, demonstrating the reversible stability of these nanoarchitectures relative to thiol exchange and negatively charged AuNP surface. The uPIC-AuNPs efficiently delivered siRNA into cultured cancer cells, facilitating significant sequence-specific gene silencing without cytotoxicity. Systemically administered uPIC-AuNPs showed appreciably longer blood circulation time compared to controls, i.e., bare AuNPs and uPICs, indicating that the conjugation of uPICs onto AuNP was crucial for enhancing blood circulation time. Finally, the uPIC-AuNPs efficiently accumulated in a subcutaneously inoculated luciferase-expressing cervical cancer (HeLa-Luc) model and achieved significant luciferase gene silencing in the tumor tissue. These results demonstrate the strong

  2. Optimized Expression and Purification for High-Activity Preparations of Algal [FeFe]-Hydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Yacoby, I.; Tegler, L. T.; Pochekailov, S.; Zhang, S.; King, P. W.

    2012-04-01

    Recombinant expression and purification of metallo-enzymes, including hydrogenases, at high-yields is challenging due to complex, and enzyme specific, post-translational maturation processes. Low fidelities of maturation result in preparations containing a significant fraction of inactive, apo-protein that are not suitable for biophysical or crystallographic studies. We describe the construction, overexpression and high-yield purification of a fusion protein consisting of the algal [2Fe2S]-ferredoxin PetF (Fd) and [FeFe]-hydrogenase HydA1. The maturation of Fd-HydA1 was optimized through improvements in culture conditions and media components used for expression. We also demonstrated that fusion of Fd to the N-terminus of HydA1, in comparison to the C-terminus, led to increased expression levels that were 4-fold higher. Together, these improvements led to enhanced HydA1 activity and improved yield after purification. The strong binding-affinity of Fd for DEAE allowed for two-step purification by ion exchange and StrepTactin affinity chromatography. In addition, the incorporation of a TEV protease site in the Fd-HydA1 linker allowed for the proteolytic removal of Fd after DEAE step, and purification of HydA1 alone by StrepTactin. In combination, this process resulted in HydA1 purification yields of 5 mg L{sup -1} of culture from E. coli with specific activities of 1000 U (U = 1 {micro}mol hydrogen evolved mg{sup -1} min{sup -1}). The [FeFe]-hydrogenases are highly efficient enzymes and their catalytic sites provide model structures for synthetic efforts to develop robust hydrogen activation catalysts. In order to characterize their structure-function properties in greater detail, and to use hydrogenases for biotechnological applications, reliable methods for rapid, high-yield expression and purification are required.

  3. Oral cancer cells may rewire alternative metabolic pathways to survive from siRNA silencing of metabolic enzymes

    International Nuclear Information System (INIS)

    Zhang, Min; Chai, Yang D; Brumbaugh, Jeffrey; Liu, Xiaojun; Rabii, Ramin; Feng, Sizhe; Misuno, Kaori; Messadi, Diana; Hu, Shen

    2014-01-01

    Cancer cells may undergo metabolic adaptations that support their growth as well as drug resistance properties. The purpose of this study is to test if oral cancer cells can overcome the metabolic defects introduced by using small interfering RNA (siRNA) to knock down their expression of important metabolic enzymes. UM1 and UM2 oral cancer cells were transfected with siRNA to transketolase (TKT) or siRNA to adenylate kinase (AK2), and Western blotting was used to confirm the knockdown. Cellular uptake of glucose and glutamine and production of lactate were compared between the cancer cells with either TKT or AK2 knockdown and those transfected with control siRNA. Statistical analysis was performed with student T-test. Despite the defect in the pentose phosphate pathway caused by siRNA knockdown of TKT, the survived UM1 or UM2 cells utilized more glucose and glutamine and secreted a significantly higher amount of lactate than the cells transferred with control siRNA. We also demonstrated that siRNA knockdown of AK2 constrained the proliferation of UM1 and UM2 cells but similarly led to an increased uptake of glucose/glutamine and production of lactate by the UM1 or UM2 cells survived from siRNA silencing of AK2. Our results indicate that the metabolic defects introduced by siRNA silencing of metabolic enzymes TKT or AK2 may be compensated by alternative feedback metabolic mechanisms, suggesting that cancer cells may overcome single defective pathways through secondary metabolic network adaptations. The highly robust nature of oral cancer cell metabolism implies that a systematic medical approach targeting multiple metabolic pathways may be needed to accomplish the continued improvement of cancer treatment

  4. Optimizations of siRNA design for the activation of gene transcription by targeting the TATA-box motif.

    Directory of Open Access Journals (Sweden)

    Miaomiao Fan

    Full Text Available Small interfering RNAs (siRNAs are widely used to repress gene expression by targeting mRNAs. Some reports reveal that siRNAs can also activate or inhibit gene expression through targeting the gene promoters. Our group has found that microRNAs (miRNAs could activate gene transcription via interaction with the TATA-box motif in gene promoters. To investigate whether siRNA targeting the same region could upregulate the promoter activity, we test the activating efficiency of siRNAs targeting the TATA-box motif of 16 genes and perform a systematic analysis to identify the common features of the functional siRNAs for effective activation of gene promoters. Further, we try various modifications to improve the activating efficiency of siRNAs and find that it is quite useful to design the promoter-targeting activating siRNA by following several rules such as (a complementary to the TATA-box-centered region; (b UA usage at the first two bases of the antisense strand; (c twenty-three nucleotides (nts in length; (d 2'-O-Methyl (2'-OMe modification at the 3' terminus of the antisense strand; (e avoiding mismatches at the 3' end of the antisense strand. The optimized activating siRNAs potently enhance the expression of interleukin-2 (IL-2 gene in human and mouse primary CD4+ T cells with a long-time effect. Taken together, our study provides a guideline for rational design the promoter-targeting siRNA to sequence-specifically enhance gene expression.

  5. Purification and concentration of uranium-bearing solutions at the plants of the Societe industrielle des minerais de l'Ouest

    International Nuclear Information System (INIS)

    Vollerin, G.

    1980-01-01

    The author describes the various processes for purification of uranium-bearing solutions used at the plants of the Societe industrielle des minerais de l'Ouest (SIMO) from their commissioning up to the present time, together with the purification circuit adopted at the two plants at present operating in Niger. (author)

  6. Solvent purification using a current of water vapour. A continuous process applicable to chemical plants treating irradiated fuels; Purification des solvants par entrainement a la vapeur d'eau. Procede continu applicable aux usines chimiques de traitement des combustibles irradies

    Energy Technology Data Exchange (ETDEWEB)

    Auchapt, P.R.; Sautray, R.R.; Girard, B.R. [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1964-07-01

    The pilot plant described in this report is intended for the continuous purification of the solvent used in the plutonium extraction plant at Marcoule, by separating the impurities (fission products). This physical separation is operated by carrying over in a water vapour stream. The contaminating products, only slightly volatile, remain in the form of the droplets and are separated; the vaporised solvent and the water vapour used are condensed and then separated. The originality of the installation resides in the system for pulverising the liquid and in the operating conditions: low working pressure and temperature. The systematic analysis of the various parameters (percentage of residue; flow, pressure and temperature ratios etc...) has shown their influence on the decontamination. The activity due to the zirconium-niobium is undetectable after treatment, and it is easy to obtain decontamination factors of 300 for the ruthenium. The, presence of uranium is favorable for the decontamination. As a conclusion, some extra-technical considerations are given concerning in particular the approximate cost price of the treated solvent per litre. (authors) [French] L'installation pilote decrite dans ce rapport est destinee a purifier, en continu, le solvant utilise a l'usine d'extraction du plutonium de Marcoule, en separant les impuretes (produits de fission). Cette separation physique est realisee par entrainement a la vapeur d'eau. Les produits contaminants, peu volatils, restant sous forme de gouttelettes, sont separes; le solvant vaporise ainsi que la vapeur d'entrainement sont condenses puis separes. L'originalite de l'installation reside dans le systeme de pulverisation du liquide et dans les conditions operatoires: faible pression et basse temperature de fonctionnement. L'analyse systematique des differents parametres (pourcentage de residus, rapport de debits, pression et temperature, etc...) a mis en evidence leur influence

  7. Multi-task learning for cross-platform siRNA efficacy prediction: an in-silico study.

    Science.gov (United States)

    Liu, Qi; Xu, Qian; Zheng, Vincent W; Xue, Hong; Cao, Zhiwei; Yang, Qiang

    2010-04-10

    Gene silencing using exogenous small interfering RNAs (siRNAs) is now a widespread molecular tool for gene functional study and new-drug target identification. The key mechanism in this technique is to design efficient siRNAs that incorporated into the RNA-induced silencing complexes (RISC) to bind and interact with the mRNA targets to repress their translations to proteins. Although considerable progress has been made in the computational analysis of siRNA binding efficacy, few joint analysis of different RNAi experiments conducted under different experimental scenarios has been done in research so far, while the joint analysis is an important issue in cross-platform siRNA efficacy prediction. A collective analysis of RNAi mechanisms for different datasets and experimental conditions can often provide new clues on the design of potent siRNAs. An elegant multi-task learning paradigm for cross-platform siRNA efficacy prediction is proposed. Experimental studies were performed on a large dataset of siRNA sequences which encompass several RNAi experiments recently conducted by different research groups. By using our multi-task learning method, the synergy among different experiments is exploited and an efficient multi-task predictor for siRNA efficacy prediction is obtained. The 19 most popular biological features for siRNA according to their jointly importance in multi-task learning were ranked. Furthermore, the hypothesis is validated out that the siRNA binding efficacy on different messenger RNAs(mRNAs) have different conditional distribution, thus the multi-task learning can be conducted by viewing tasks at an "mRNA"-level rather than at the "experiment"-level. Such distribution diversity derived from siRNAs bound to different mRNAs help indicate that the properties of target mRNA have important implications on the siRNA binding efficacy. The knowledge gained from our study provides useful insights on how to analyze various cross-platform RNAi data for uncovering

  8. Multi-task learning for cross-platform siRNA efficacy prediction: an in-silico study

    Directory of Open Access Journals (Sweden)

    Xue Hong

    2010-04-01

    Full Text Available Abstract Background Gene silencing using exogenous small interfering RNAs (siRNAs is now a widespread molecular tool for gene functional study and new-drug target identification. The key mechanism in this technique is to design efficient siRNAs that incorporated into the RNA-induced silencing complexes (RISC to bind and interact with the mRNA targets to repress their translations to proteins. Although considerable progress has been made in the computational analysis of siRNA binding efficacy, few joint analysis of different RNAi experiments conducted under different experimental scenarios has been done in research so far, while the joint analysis is an important issue in cross-platform siRNA efficacy prediction. A collective analysis of RNAi mechanisms for different datasets and experimental conditions can often provide new clues on the design of potent siRNAs. Results An elegant multi-task learning paradigm for cross-platform siRNA efficacy prediction is proposed. Experimental studies were performed on a large dataset of siRNA sequences which encompass several RNAi experiments recently conducted by different research groups. By using our multi-task learning method, the synergy among different experiments is exploited and an efficient multi-task predictor for siRNA efficacy prediction is obtained. The 19 most popular biological features for siRNA according to their jointly importance in multi-task learning were ranked. Furthermore, the hypothesis is validated out that the siRNA binding efficacy on different messenger RNAs(mRNAs have different conditional distribution, thus the multi-task learning can be conducted by viewing tasks at an "mRNA"-level rather than at the "experiment"-level. Such distribution diversity derived from siRNAs bound to different mRNAs help indicate that the properties of target mRNA have important implications on the siRNA binding efficacy. Conclusions The knowledge gained from our study provides useful insights on how to

  9. Identification and characterization of microRNAs and endogenous siRNAs in Schistosoma japonicum

    Directory of Open Access Journals (Sweden)

    Wang Heng

    2010-01-01

    Full Text Available Abstract Background Small endogenous non-coding RNAs (sncRNAs such as small interfering RNA (siRNA, microRNA and other small RNA transcripts are derived from distinct loci in the genome and play critical roles in RNA-mediated gene silencing mechanisms in plants and metazoa. They are approximately 22 nucleotides long; regulate mRNA stability through perfect or imperfect match to the targets. The biological activities of sncRNAs have been related to many biological events, from resistance to microbe infections to cellular differentiation. The development of the zoonotic parasite Schistosoma japonicum parasite includes multiple steps of morphological alterations and biological differentiations, which provide a unique model for studies on the functions of small RNAs. Characterization of the genome-wide transcription of the sncRNAs will be a major step in understanding of the parasite biology. The objective of this study is to investigate the transcriptional profile and potential function of the small non-coding RNAs in the development of S. japanicum. Results The endogenous siRNAs were found mainly derived from transposable elements (TE or transposons and the natural antisense transcripts (NAT. In contrast to other organisms, the TE-derived siRNAs in S. japonicum were more predominant than other sncRNAs including microRNAs (miRNAs. Further, there were distinct length and 3'end variations in the sncRNAs, which were associated with the developmental differentiation of the parasite. Among the identified miRNA transcripts, there were 38 unique to S. japonicum and 16 that belonged to 13 miRNA families are common to other metazoan lineages. These miRNAs were either ubiquitously expressed, or they exhibited specific expression patterns related to the developmental stages or sex. Genes that encoded miRNAs are mainly located in clusters within the genome of S. japonicum. However, genes within one cluster could be differentially transcribed, which suggested

  10. Thermoresponsive pegylated bubble liposome nanovectors for efficient siRNA delivery via endosomal escape

    KAUST Repository

    Alamoudi, Kholod; Martins, Patricia; Croissant, Jonas G.; Patil, Sachin; Omar, Haneen; Khashab, Niveen M.

    2017-01-01

    Improving the delivery of siRNA into cancer cells via bubble liposomes. Designing a thermoresponsive pegylated liposome through the introduction of ammonium bicarbonate salt into liposomes so as to control their endosomal escape for gene therapy.A sub-200 nm nanovector was fully characterized and examined for cellular uptake, cytotoxicity, endosomal escape and gene silencing.The siRNA-liposomes were internalized into cancer cells within 5 min and then released siRNAs in the cytosol prior to lysosomal degradation upon external temperature elevation. This was confirmed by confocal bioimaging and gene silencing reaching up to 90% and further demonstrated by the protein inhibition of both target genes.The thermoresponsiveness of ammonium bicarbonate containing liposomes enabled the rapid endosomal escape of the particles and resulted in an efficient gene silencing.

  11. Thermoresponsive pegylated bubble liposome nanovectors for efficient siRNA delivery via endosomal escape

    KAUST Repository

    Alamoudi, Kholod

    2017-05-19

    Improving the delivery of siRNA into cancer cells via bubble liposomes. Designing a thermoresponsive pegylated liposome through the introduction of ammonium bicarbonate salt into liposomes so as to control their endosomal escape for gene therapy.A sub-200 nm nanovector was fully characterized and examined for cellular uptake, cytotoxicity, endosomal escape and gene silencing.The siRNA-liposomes were internalized into cancer cells within 5 min and then released siRNAs in the cytosol prior to lysosomal degradation upon external temperature elevation. This was confirmed by confocal bioimaging and gene silencing reaching up to 90% and further demonstrated by the protein inhibition of both target genes.The thermoresponsiveness of ammonium bicarbonate containing liposomes enabled the rapid endosomal escape of the particles and resulted in an efficient gene silencing.

  12. Inhibition of Hepatitis B virus cccDNA replication by siRNA

    International Nuclear Information System (INIS)

    Li Guiqiu; Gu Hongxi; Li Di; Xu Weizhen

    2007-01-01

    The development of an effective therapy for Hepatitis B virus (HBV) infection is still a challenge. Progress in RNA interference (RNAi) has shed slight on developing a new anti-HBV strategy. Here, we present a series of experiments showing a significant reduction in HBV transcripts and replication intermediates in HepG2.2.15 cells by vector-based siRNA targeted nuclear localization signal (NLS) region. More importantly, we showed that siRNA1 markedly inhibited HBV covalently closed circular DNA (cccDNA) replication. Our results indicated that HBV NLS may serve as a novel RNAi target to combat HBV infection, which can enhance anti-HBV efficacy and overcome the drawbacks of current therapies

  13. siRNA targeting PLK-1 induces apoptosis of synoviocytes in rheumatoid arthritis

    International Nuclear Information System (INIS)

    Wada, Makoto; Kawahito, Yutaka; Kimura, Shinya; Kohno, Masataka; Ishino, Hidetaka; Kimura, Mizuho; Omoto, Atsushi; Yamamoto, Aihiro; Hamaguchi, Masahide; Tsubouchi, Yasunori; Tokunaga, Daisaku; Hojo, Tatsuya; Ashihara, Eishi; Maekawa, Taira; Yoshikawa, Toshikazu

    2007-01-01

    Polo-like kinase-1 (PLK-1) is a member of the PLK family and participates in the control of cell mitosis. Here, we show that immunoreactive PLK-1 is strongly expressed in synoviocytes and some infiltrative mononuclear cells in synovial tissues from patients with rheumatoid arthritis (RA), while patients with osteoarthritis and injury show little or no expression of PLK-1 in synovial tissues. Western blot analysis shows that PLK is expressed and its expression is enhanced by IL-1β in RA synoviocytes. IL-1β also enhanced the cell growth of RA synoviocytes. Moreover, siRNA targeted against PLK-1 significantly decreases the expression of PLK-1 of RA synoviocytes stimulated by IL-1β and suppresses the proliferation of these synoviocytes through apoptosis. These findings suggest that PLK-1 plays a critical role in the proliferation of RA synoviocytes leading to bone destruction, and siRNA against PLK-1 is potentially useful for the treatment of RA

  14. Targeted Delivery of siRNA to Macrophages for Anti-inflammatory Treatment

    OpenAIRE

    Kim, Sang-Soo; Ye, Chunting; Kumar, Priti; Chiu, Isaac; Subramanya, Sandesh; Wu, Haoquan; Shankar, Premlata; Manjunath, N

    2010-01-01

    Inflammation mediated by tumor necrosis factor-α (TNF-α) and the associated neuronal apoptosis characterizes a number of neurologic disorders. Macrophages and microglial cells are believed to be the major source of TNF-α in the central nervous system (CNS). Here, we show that suppression of TNF-α by targeted delivery of small interfering RNA (siRNA) to macrophage/microglial cells dramatically reduces lipopolysaccharide (LPS)-induced neuroinflammation and neuronal apoptosis in vivo. Because ma...

  15. In vivo silencing of alpha-synuclein using naked siRNA

    OpenAIRE

    Charisse Klaus; Toudjarska Ivanka; Kent Caroline; Hinkle Kelly; Ogholikhan Sina; He Zhen; Braithwaite Adam; Lincoln Sarah; Zehr Cynthia; Hope Andrew; Bumcrot David; Melrose Heather; Lewis Jada; Braich Ravi; Pandey Rajendra K

    2008-01-01

    Abstract Background Overexpression of α-synuclein (SNCA) in families with multiplication mutations causes parkinsonism and subsequent dementia, characterized by diffuse Lewy Body disease post-mortem. Genetic variability in SNCA contributes to risk of idiopathic Parkinson's disease (PD), possibly as a result of overexpression. SNCA downregulation is therefore a valid therapeutic target for PD. Results We have identified human and murine-specific siRNA molecules which reduce SNCA in vitro. As a...

  16. Synergistic effect of Brønsted acid and platinum on purification of automobile exhaust gases.

    Science.gov (United States)

    Fu, Wei; Li, Xin-Hao; Bao, Hong-Liang; Wang, Kai-Xue; Wei, Xiao; Cai, Yi-Yu; Chen, Jie-Sheng

    2013-01-01

    The catalytic purification of automobile exhaust gases (CO, NOx and hydrocarbons) is one of the most practiced conversion processes used to lower the emissions and to reduce the air pollution. Nevertheless, the good performance of exhaust gas purification catalysts often requires the high consumption of noble metals such as platinum. Here we report that the Brønsted acid sites on the external surface of a microporous silicoaluminophosphate (SAPO) act as a promoter for exhaust gas purification, effectively cutting the loading amount of platinum in the catalyst without sacrifice of performance. It is revealed that in the Pt-loaded SAPO-CHA catalyst, there exists a remarkable synergistic effect between the Brønsted acid sites and the Pt nanoparticles, the former helping to adsorb and activate the hydrocarbon molecules for NO reduction during the catalytic process. The thermal stability of SAPO-CHA also makes the composite catalyst stable and reusable without activity decay.

  17. [Efficiency of the preparation "Ekolan-M" for purification of oil polluted soil].

    Science.gov (United States)

    Nogina, T M; Dumanskaia, T U; Khomenko, L A; Podgorskiĭ, V S

    2012-01-01

    The efficiency of purification of oil contaminated loamy chernozem by the preparation "Ekolan-M" was investigated. During 12 months a complex soil bioremediation using the preparation and alfalfa, as the land-improving plant, at the final stage of purification resulted in the reduction of hydrocarbon content by 97.0%, and without the preparation - by 65.5 %. In the version of experiment with the preparation a 100% decrease of soil phytotoxicity was achieved and a significant stimulation of plant growth and development was observed. The process of soil purification was accompanied by intensive development of hydrocarbon-oxidizing microorganisms, the amount of which during the process of oil concentration gradually decreased, approaching the level in the control uncontaminated soil.

  18. Synergistic effect of Brønsted acid and platinum on purification of automobile exhaust gases

    Science.gov (United States)

    Fu, Wei; Li, Xin-Hao; Bao, Hong-Liang; Wang, Kai-Xue; Wei, Xiao; Cai, Yi-Yu; Chen, Jie-Sheng

    2013-01-01

    The catalytic purification of automobile exhaust gases (CO, NOx and hydrocarbons) is one of the most practiced conversion processes used to lower the emissions and to reduce the air pollution. Nevertheless, the good performance of exhaust gas purification catalysts often requires the high consumption of noble metals such as platinum. Here we report that the Brønsted acid sites on the external surface of a microporous silicoaluminophosphate (SAPO) act as a promoter for exhaust gas purification, effectively cutting the loading amount of platinum in the catalyst without sacrifice of performance. It is revealed that in the Pt-loaded SAPO-CHA catalyst, there exists a remarkable synergistic effect between the Brønsted acid sites and the Pt nanoparticles, the former helping to adsorb and activate the hydrocarbon molecules for NO reduction during the catalytic process. The thermal stability of SAPO-CHA also makes the composite catalyst stable and reusable without activity decay. PMID:23907148

  19. Chimeric peptide-mediated siRNA transduction to inhibit HIV-1 infection.

    Science.gov (United States)

    Bivalkar-Mehla, Shalmali; Mehla, Rajeev; Chauhan, Ashok

    2017-04-01

    Persistent human immunodeficiency virus 1 (HIV-1) infection provokes immune activation and depletes CD4 +  lymphocytes, leading to acquired immunodeficiency syndrome. Uninterrupted administration of combination antiretroviral therapy (cART) in HIV-infected patients suppresses viral replication to below the detectable level and partially restores the immune system. However, cART-unresponsive residual HIV-1 infection and elusive transcriptionally silent but reactivatable viral reservoirs maintain a permanent viral DNA blue print. The virus rebounds within a few weeks after interruption of suppressive therapy. Adjunct gene therapy to control viral replication by ribonucleic acid interference (RNAi) is a post-transcriptional gene silencing strategy that could suppress residual HIV-1 burden and overcome viral resistance. Small interfering ribonucleic acids (siRNAs) are efficient transcriptional inhibitors, but need delivery systems to reach inside target cells. We investigated the potential of chimeric peptide (FP-PTD) to deliver specific siRNAs to HIV-1-susceptible and permissive cells. Chimeric FP-PTD peptide was designed with an RNA binding domain (PTD) to bind siRNA and a cell fusion peptide domain (FP) to enter cells. FP-PTD-siRNA complex entered and inhibited HIV-1 replication in susceptible cells, and could be a candidate for in vivo testing.

  20. Efficient Inhibition of wear debris-induced inflammation by locally delivered siRNA

    International Nuclear Information System (INIS)

    Peng Xiaochun; Tao Kun; Cheng Tao; Zhu Junfeng; Zhang Xianlong

    2008-01-01

    Aseptic loosening is the most common long-term complication of total joint replacement, which is associated with the generation of wear debris. The purpose of this study was to investigate the inhibitory effect of small interfering RNA (siRNA) targeting tumor necrosis factor-α (TNF-α) on wear debris-induced inflammation. A local delivery of lentivirus-mediated TNF-α siRNA into the modified murine air pouch, which was stimulated by polymethylmethacrylate (PMMA) particles, resulted in significant blockage of TNF-α both in mRNA and protein levels for up to 4 weeks. In addition, significant down-regulation of interleukin-1 (IL-1) and interleukin-6 (IL-6) was observed in TNF-α siRNA-treated pouches. The safety profile of gene therapy was proven by Bioluminescent assay and quantitative fluorescent flux. Histological analysis revealed less inflammatory responses (thinner pouch membrane and decreased cellular infiltration) in TNF-α siRNA-treated pouches. These findings suggest that local delivery of TNF-α siRNA might be an excellent therapeutic candidate to inhibit particle-induced inflammation.

  1. Intraventricular Delivery of siRNA Nanoparticles to the Central Nervous System

    Directory of Open Access Journals (Sweden)

    Rishab Shyam

    2015-01-01

    Full Text Available Alzheimer's disease (AD is a progressive neurodegenerative disease currently lacking effective treatment. Efficient delivery of siRNA via nanoparticles may emerge as a viable therapeutic approach to treat AD and other central nervous system disorders. We report here the use of a linear polyethyleneimine (LPEI-g-polyethylene glycol (PEG copolymer-based micellar nanoparticle system to deliver siRNA targeting BACE1 and APP, two therapeutic targets of AD. Using LPEI-siRNA nanoparticles against either BACE1 or APP in cultured mouse neuroblastoma (N2a cells, we observe selective knockdown, respectively, of BACE1 or APP. The encapsulation of siRNA by LPEI-g-PEG carriers, with different grafting degrees of PEG, leads to the formation of micellar nanoparticles with distinct morphologies, including worm-like, rod-like, or spherical nanoparticles. By infusing these shaped nanoparticles into mouse lateral ventricles, we show that rod-shaped nanoparticles achieved the most efficient knockdown of BACE1 in the brain. Furthermore, such knockdown is evident in spinal cords of these treated mice. Taken together, our findings indicate that the shape of siRNA-encapsulated nanoparticles is an important determinant for their delivery and gene knockdown efficiency in the central nervous system.

  2. Topical treatment of herpes simplex virus infection with enzymatically created siRNA swarm.

    Science.gov (United States)

    Paavilainen, Henrik; Lehtinen, Jenni; Romanovskaya, Alesia; Nygårdas, Michaela; Bamford, Dennis H; Poranen, Minna M; Hukkanen, Veijo

    2017-01-01

    Herpes simplex virus (HSV) is a common human pathogen. Despite current antivirals, it causes a significant medical burden. Drug resistant strains exist and they are especially prevalent in immunocompromised patients and in HSV eye infections. New treatment modalities are needed. BALB/c mice were corneally infected with HSV and subsequently treated with a swarm of enzymatically created, Dicer-substrate small interfering RNA (siRNA) molecules that targeted the HSV gene UL29. Two infection models were used, one in which the infection was predominantly peripheral and another in which it spread to the central nervous system. Mouse survival, as well as viral spread, load, latency and peripheral shedding, was studied. The anti-HSV-UL29 siRNA swarm alleviated HSV infection symptoms, inhibited viral shedding and replication and had a favourable effect on mouse survival. Treatment with anti-HSV-UL29 siRNA swarm reduced symptoms and viral spread in HSV infection of mice and also inhibited local viral replication in mouse corneas.

  3. In vivo silencing of alpha-synuclein using naked siRNA

    Directory of Open Access Journals (Sweden)

    Charisse Klaus

    2008-11-01

    Full Text Available Abstract Background Overexpression of α-synuclein (SNCA in families with multiplication mutations causes parkinsonism and subsequent dementia, characterized by diffuse Lewy Body disease post-mortem. Genetic variability in SNCA contributes to risk of idiopathic Parkinson's disease (PD, possibly as a result of overexpression. SNCA downregulation is therefore a valid therapeutic target for PD. Results We have identified human and murine-specific siRNA molecules which reduce SNCA in vitro. As a proof of concept, we demonstrate that direct infusion of chemically modified (naked, murine-specific siRNA into the hippocampus significantly reduces SNCA levels. Reduction of SNCA in the hippocampus and cortex persists for a minimum of 1 week post-infusion with recovery nearing control levels by 3 weeks post-infusion. Conclusion We have developed naked gene-specific siRNAs that silence expression of SNCA in vivo. This approach may prove beneficial toward our understanding of the endogenous functional equilibrium of SNCA, its role in disease, and eventually as a therapeutic strategy for α-synucleinopathies resulting from SNCA overexpression.

  4. In vivo silencing of alpha-synuclein using naked siRNA

    Science.gov (United States)

    Lewis, Jada; Melrose, Heather; Bumcrot, David; Hope, Andrew; Zehr, Cynthia; Lincoln, Sarah; Braithwaite, Adam; He, Zhen; Ogholikhan, Sina; Hinkle, Kelly; Kent, Caroline; Toudjarska, Ivanka; Charisse, Klaus; Braich, Ravi; Pandey, Rajendra K; Heckman, Michael; Maraganore, Demetrius M; Crook, Julia; Farrer, Matthew J

    2008-01-01

    Background Overexpression of α-synuclein (SNCA) in families with multiplication mutations causes parkinsonism and subsequent dementia, characterized by diffuse Lewy Body disease post-mortem. Genetic variability in SNCA contributes to risk of idiopathic Parkinson's disease (PD), possibly as a result of overexpression. SNCA downregulation is therefore a valid therapeutic target for PD. Results We have identified human and murine-specific siRNA molecules which reduce SNCA in vitro. As a proof of concept, we demonstrate that direct infusion of chemically modified (naked), murine-specific siRNA into the hippocampus significantly reduces SNCA levels. Reduction of SNCA in the hippocampus and cortex persists for a minimum of 1 week post-infusion with recovery nearing control levels by 3 weeks post-infusion. Conclusion We have developed naked gene-specific siRNAs that silence expression of SNCA in vivo. This approach may prove beneficial toward our understanding of the endogenous functional equilibrium of SNCA, its role in disease, and eventually as a therapeutic strategy for α-synucleinopathies resulting from SNCA overexpression. PMID:18976489

  5. NIR-to-visible upconversion nanoparticles for fluorescent labeling and targeted delivery of siRNA

    International Nuclear Information System (INIS)

    Jiang Shan; Zhang Yong; Lim, Kian Meng; Sim, Eugene K W; Ye Lei

    2009-01-01

    Near-infrared (NIR)-to-visible upconversion fluorescent nanoparticles were synthesized and used for imaging and targeted delivery of small interfering RNA (siRNA) to cancer cells. Silica-coated NaYF 4 upconversion nanoparticles (UCNs) co-doped with lanthanide ions (Yb/Er) were synthesized. Folic acid and anti-Her2 antibody conjugated UCNs were used to fluorescently label the folate receptors of HT-29 cells and Her2 receptors of SK-BR-3 cells, respectively. The intracellular uptake of the folic acid and antibody conjugated UCNs was visualized using a confocal fluorescence microscope equipped with an NIR laser. siRNA was attached to anti-Her2 antibody conjugated UCNs and the delivery of these nanoparticles to SK-BR-3 cells was studied. Meanwhile, a luciferase assay was established to confirm the gene silencing effect of siRNA. Upconversion nanoparticles can serve as a fluorescent probe and delivery system for simultaneous imaging and delivery of biological molecules.

  6. NIR-to-visible upconversion nanoparticles for fluorescent labeling and targeted delivery of siRNA

    Science.gov (United States)

    Jiang, Shan; Zhang, Yong; Lim, Kian Meng; Sim, Eugene K. W.; Ye, Lei

    2009-04-01

    Near-infrared (NIR)-to-visible upconversion fluorescent nanoparticles were synthesized and used for imaging and targeted delivery of small interfering RNA (siRNA) to cancer cells. Silica-coated NaYF4 upconversion nanoparticles (UCNs) co-doped with lanthanide ions (Yb/Er) were synthesized. Folic acid and anti-Her2 antibody conjugated UCNs were used to fluorescently label the folate receptors of HT-29 cells and Her2 receptors of SK-BR-3 cells, respectively. The intracellular uptake of the folic acid and antibody conjugated UCNs was visualized using a confocal fluorescence microscope equipped with an NIR laser. siRNA was attached to anti-Her2 antibody conjugated UCNs and the delivery of these nanoparticles to SK-BR-3 cells was studied. Meanwhile, a luciferase assay was established to confirm the gene silencing effect of siRNA. Upconversion nanoparticles can serve as a fluorescent probe and delivery system for simultaneous imaging and delivery of biological molecules.

  7. Utility of MicroRNAs and siRNAs in Cervical Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Sacnite del Mar Díaz-González

    2015-01-01

    Full Text Available MicroRNAs and siRNAs belong to a family of small noncoding RNAs which bind through partial sequence complementarity to 3′-UTR regions of mRNA from target genes, resulting in the regulation of gene expression. MicroRNAs have become an attractive target for genetic and pharmacological modulation due to the critical function of their target proteins in several signaling pathways, and their expression profiles have been found to be altered in various cancers. A promising technology platform for selective silencing of cell and/or viral gene expression using siRNAs is currently in development. Cervical cancer is the most common cancer in women in the developing world and sexually transmitted infection with HPV is the cause of this malignancy. Therefore, a cascade of abnormal events is induced during cervical carcinogenesis, including the induction of genomic instability, reprogramming of cellular metabolic pathways, deregulation of cell proliferation, inhibition of apoptotic mechanisms, disruption of cell cycle control mechanisms, and alteration of gene expression. Thus, in the present review article, we highlight new research on microRNA expression profiles which may be utilized as biomarkers for cervical cancer. Furthermore, we discuss selective silencing of HPV E6 and E7 with siRNAs which represents a potential gene therapy strategy against cervical cancer.

  8. Experimental study and simulation of phosphorus purification effects of bioretention systems on urban surface runoff.

    Directory of Open Access Journals (Sweden)

    Jiake Li

    Full Text Available Excessive phosphorus (P contributes to eutrophication by degrading water quality and limiting human use of water resources. Identifying economic and convenient methods to control soluble reactive phosphorus (SRP pollution in urban runoff is the key point of rainwater management strategies. Through three series of different tests involving influencing factors, continuous operation and intermittent operation, this study explored the purification effects of bioretention tanks under different experimental conditions, it included nine intermittent tests, single field continuous test with three groups of different fillers (Fly ash mixed with sand, Blast furnace slag, and Soil, and eight intermittent tests with single filler (Blast furnace slag mixed with sand. Among the three filler combinations studied, the filler with fly ash mixed with sand achieved the best pollution reduction efficiency. The setting of the submerged zone exerted minimal influence on the P removal of the three filler combinations. An extension of the dry period slightly promoted the P purification effect. The combination of fly ash mixed with sand demonstrated a positive purification effect on SRP during short- or long-term simulated rainfall duration. Blast furnace slag also presented a positive purification effect in the short term, although its continuous purification effect on SRP was poor in the long term. The purification abilities of soil in the short and long terms were weak. Under intermittent operations across different seasons, SRP removal was unstable, and effluent concentration processes were different. The purification effect of the bioretention system on SRP was predicted through partial least squares regression (PLS modeling analysis. The event mean concentration removal of SRP was positively related to the adsorption capacity of filler and rainfall interval time and negatively related to submerged zones, influent concentration and volume.

  9. Concept of off-gas purification in reprocessing plants

    International Nuclear Information System (INIS)

    Henrich, E.; von Ammon, R.

    1986-01-01

    Concepts and individual processes for the off-gas purification in reprocessing plants are described which are suited to achieve a better retention of the gaseous and volatile radionuclides 129 I, 85 Kr, 14 C, and tritium. Improved and new process steps have been developed to the cold pilot plant scale. Essential individual process steps are an efficient iodine desorption from the dissolver solution, improved and new off-gas scrubs with nitric acid, a cryogenic as well as a selective absorption process for rare gas recovery plus the required prepurification steps and a process for the continuous and pressure-free fixation and storage of krypton in a metal matrix. Individual facilities have been selected and combined to investigate integrated dissolver off-gas systems. Advanced concepts based on a process using low flows and loads of all off-gas streams including the cell ventilation off-gas are briefly discussed

  10. Ternary complexes of folate-PEG-appended dendrimer (G4)/α-cyclodextrin conjugate, siRNA and low-molecular-weight polysaccharide sacran as a novel tumor-selective siRNA delivery system.

    Science.gov (United States)

    Ohyama, Ayumu; Higashi, Taishi; Motoyama, Keiichi; Arima, Hidetoshi

    2017-06-01

    We previously developed a tumor-selective siRNA carrier by preparing polyamidoamine dendrimer (generation 4, G4) conjugates with α-cyclodextrin and folate-polyethylene glycol (Fol-PαC (G4)). In the present study, we developed ternary complexes of Fol-PαC (G4)/siRNA with low-molecular-weight-sacrans to achieve more effective siRNA transfer activity. Among the different molecular-weight sacrans, i.e. sacran 100, 1000 and 10,000 (MW 44,889Da, 943,692Da and 1,488,281Da, respectively), sacran 100 significantly increased the cellular uptake and the RNAi effects of Fol-PαC (G4)/siRNA binary complex with negligible cytotoxicity in KB cells (folate receptor-α positive cells). In addition, the ζ-potential and particle size of Fol-PαC (G4)/siRNA complex were decreased by the ternary complexation with sacran 100. Importantly, the in vivo RNAi effect of the ternary complex after the intravenous administration to tumor-bearing BALB/c mice was significantly higher than that of the binary complex. In conclusion, Fol-PαC (G4)/siRNA/sacran 100 ternary complex has a potential as a novel tumor-selective siRNA delivery system. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Characterization and vectorization of siRNA targeting RET/PTC1 in human papillary thyroid carcinoma cells

    Directory of Open Access Journals (Sweden)

    Massade L.

    2011-10-01

    Full Text Available RET/PTC1 fusion oncogene is the most common genetic alteration identified to date in thyroid papillary carcinomas (PTC and represents a good target for small interfering RNA (siRNA. Our aim was: i to target the RET/PTC1 oncogene by siRNAs, ii to assess the knockdown effects on cell growth and cell cycle regulation and iii to vectorize it in order to protect it from degradation. Methods. Human cell lines expressing RET/PTC1 were transfected by siRNA RET/PTC1, inhibition of the oncogene expression was assessed by qRT-PCR and by Western blot. Conjugation of siRNA RET/PTC1 to squalene was performed by coupling it to squalene. In vivo studies are performed in nude mice. Conclusion. In this short communication, we report the main published results obtained during last years.

  12. Screening of siRNA nanoparticles for delivery to airway epithelial cells using high-content analysis

    LENUS (Irish Health Repository)

    Hibbitts, Alan

    2011-08-01

    Aims: Delivery of siRNA to the lungs via inhalation offers a unique opportunity to develop a new treatment paradigm for a range of respiratory conditions. However, progress has been greatly hindered by safety and delivery issues. This study developed a high-throughput method for screening novel nanotechnologies for pulmonary siRNA delivery. Methodology: Following physicochemical analysis, the ability of PEI–PEG–siRNA nanoparticles to facilitate siRNA delivery was determined using high-content analysis (HCA) in Calu-3 cells. Results obtained from HCA were validated using confocal microscopy. Finally, cytotoxicity of the PEI–PEG–siRNA particles was analyzed by HCA using the Cellomics® multiparameter cytotoxicity assay. Conclusion: PEI–PEG–siRNA nanoparticles facilitated increased siRNA uptake and luciferase knockdown in Calu-3 cells compared with PEI–siRNA.

  13. Effects of a human plasma membrane-associated sialidase siRNA on prostate cancer invasion

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaojie [Department of Pathophysiology, Prostate Diseases Prevention and Treatment Research Centre, Norman Bethune Medical School, Jilin University, Changchun (China); Taizhou Polytechnic College, Taizhou (China); Zhang, Ling; Shao, Yueting; Liang, Zuowen; Shao, Chen; Wang, Bo; Guo, Baofeng; Li, Na; Zhao, Xuejian [Department of Pathophysiology, Prostate Diseases Prevention and Treatment Research Centre, Norman Bethune Medical School, Jilin University, Changchun (China); Li, Yang, E-mail: lyang@jlu.edu.cn [Department of Pathophysiology, Prostate Diseases Prevention and Treatment Research Centre, Norman Bethune Medical School, Jilin University, Changchun (China); Xu, Deqi [Laboratory of Enteric and Sexually Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD (United States)

    2011-12-16

    Highlights: Black-Right-Pointing-Pointer Neu3 is as one of the sialidases and regulates cell surface functions. Black-Right-Pointing-Pointer A Neu3-specific siRNA inhibited prostrate cancer cell invasion and migration. Black-Right-Pointing-Pointer The Neu3-specific siRNA inhibited prostate cancer metastasis in mice. Black-Right-Pointing-Pointer Targeting Neu3 may have utility for gene-based therapy of human cancer metastasis. -- Abstract: Human plasma membrane-associated sialidase (Neu3) is one of several sialidases that hydrolyze sialic acids in the terminal position of the carbohydrate groups of glycolipids and glycoproteins. Neu3 is mainly localized in plasma membranes and plays crucial roles in the regulation of cell surface functions. In this study, we investigated the effects and molecular mechanisms of Neu3 on cell invasion and migration in vivo and in vitro. Initially, we found that the levels of Neu3 expression were higher in prostate cancer tissues and cell lines than in normal prostate tissues based on RT-PCR and Western blotting analyses. We then applied a Neu3 siRNA approach to block Neu3 signaling using PC-3M cells as model cells. Transwell invasion assays and wound assays showed significantly decreased invasion and migration potential in the Neu3 siRNA-transfected cells. RT-PCR and Western blotting analyses revealed that Neu3 knockdown decreased the expressions of the matrix metalloproteinases MMP-2 and MMP-9. In vivo, mice injected with PC-3M cell tumors were evaluated by SPECT/CT to determine the presence of bone metastases. Mice treated with attenuated Salmonella carrying the Neu3 siRNA developed fewer bone metastases than mice treated with attenuated Salmonella carrying a control Scramble siRNA, attenuated Salmonella alone or PBS. The results for bone metastasis detection by pathology were consistent with the data obtained by SPECT/CT. Tumor blocks were evaluated by histochemical, RT-PCR and Western blotting analyses. The results revealed

  14. Layer-by-layer nanoparticles as an efficient siRNA delivery vehicle for SPARC silencing.

    Science.gov (United States)

    Tan, Yang Fei; Mundargi, Raghavendra C; Chen, Min Hui Averil; Lessig, Jacqueline; Neu, Björn; Venkatraman, Subbu S; Wong, Tina T

    2014-05-14

    Efficient and safe delivery systems for siRNA therapeutics remain a challenge. Elevated secreted protein, acidic, and rich in cysteine (SPARC) protein expression is associated with tissue scarring and fibrosis. Here we investigate the feasibility of encapsulating SPARC-siRNA in the bilayers of layer-by-layer (LbL) nanoparticles (NPs) with poly(L-arginine) (ARG) and dextran (DXS) as polyelectrolytes. Cellular binding and uptake of LbL NPs as well as siRNA delivery were studied in FibroGRO cells. siGLO-siRNA and SPARC-siRNA were efficiently coated onto hydroxyapatite nanoparticles. The multilayered NPs were characterized with regard to particle size, zeta potential and surface morphology using dynamic light scattering and transmission electron microscopy. The SPARC-gene silencing and mRNA levels were analyzed using ChemiDOC western blot technique and RT-PCR. The multilayer SPARC-siRNA incorporated nanoparticles are about 200 nm in diameter and are efficiently internalized into FibroGRO cells. Their intracellular fate was also followed by tagging with suitable reporter siRNA as well as with lysotracker dye; confocal microscopy clearly indicates endosomal escape of the particles. Significant (60%) SPARC-gene knock down was achieved by using 0.4 pmole siRNA/μg of LbL NPs in FibroGRO cells and the relative expression of SPARC mRNA reduced significantly (60%) against untreated cells. The cytotoxicity as evaluated by xCelligence real-time cell proliferation and MTT cell assay, indicated that the SPARC-siRNA-loaded LbL NPs are non-toxic. In conclusion, the LbL NP system described provides a promising, safe and efficient delivery platform as a non-viral vector for siRNA delivery that uses biopolymers to enhance the gene knock down efficiency for the development of siRNA therapeutics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Heparin-binding peptide as a novel affinity tag for purification of recombinant proteins.

    Science.gov (United States)

    Morris, Jacqueline; Jayanthi, Srinivas; Langston, Rebekah; Daily, Anna; Kight, Alicia; McNabb, David S; Henry, Ralph; Kumar, Thallapuranam Krishnaswamy Suresh

    2016-10-01

    Purification of recombinant proteins constitutes a significant part of the downstream processing in biopharmaceutical industries. Major costs involved in the production of bio-therapeutics mainly depend on the number of purification steps used during the downstream process. Affinity chromatography is a widely used method for the purification of recombinant proteins expressed in different expression host platforms. Recombinant protein purification is achieved by fusing appropriate affinity tags to either N- or C- terminus of the target recombinant proteins. Currently available protein/peptide affinity tags have proved quite useful in the purification of recombinant proteins. However, these affinity tags suffer from specific limitations in their use under different conditions of purification. In this study, we have designed a novel 34-amino acid heparin-binding affinity tag (HB-tag) for the purification of recombinant proteins expressed in Escherichia coli (E. coli) cells. HB-tag fused recombinant proteins were overexpressed in E. coli in high yields. A one-step heparin-Sepharose-based affinity chromatography protocol was developed to purify HB-fused recombinant proteins to homogeneity using a simple sodium chloride step gradient elution. The HB-tag has also been shown to facilitate the purification of target recombinant proteins from their 8 M urea denatured state(s). The HB-tag has been demonstrated to be successfully released from the fusion protein by an appropriate protease treatment to obtain the recombinant target protein(s) in high yields. Results of the two-dimensional NMR spectroscopy experiments indicate that the purified recombinant target protein(s) exist in the native conformation. Polyclonal antibodies raised against the HB-peptide sequence, exhibited high binding specificity and sensitivity to the HB-fused recombinant proteins (∼10 ng) in different crude cell extracts obtained from diverse expression hosts. In our opinion, the HB-tag provides a

  16. Photocatalytic materials and technologies for air purification.

    Science.gov (United States)

    Ren, Hangjuan; Koshy, Pramod; Chen, Wen-Fan; Qi, Shaohua; Sorrell, Charles Christopher

    2017-03-05

    Since there is increasing concern for the impact of air quality on human health, the present work surveys the materials and technologies for air purification using photocatalytic materials. The coverage includes (1) current photocatalytic materials for the decomposition of chemical contaminants and disinfection of pathogens present in air and (2) photocatalytic air purification systems that are used currently and under development. The present work focuses on five main themes. First, the mechanisms of photodegradation and photodisinfection are explained. Second, system designs for photocatalytic air purification are surveyed. Third, the photocatalytic materials used for air purification and their characteristics are considered, including both conventional and more recently developed photocatalysts. Fourth, the methods used to fabricate these materials are discussed. Fifth, the most significant coverage is devoted to materials design strategies aimed at improving the performance of photocatalysts for air purification. The review concludes with a brief consideration of promising future directions for materials research in photocatalysis. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. CO 2-scrubbing and methanation as purification system for PEFC

    Science.gov (United States)

    Ledjeff-Hey, K.; Roes, J.; Wolters, R.

    Hydrogen is usually produced by steam reforming of natural gas in large-scale processes. The reformate consists of hydrogen, carbon dioxide, carbon monoxide, and residues of hydrocarbons. Since the anode catalyst of a polymer electrolyte membrane fuel cell (PEFC) is usually based on platinum, which is easily poisoned by carbon monoxide, the conditioned feed gas should contain less than 100 ppmv CO, and preferably, less than 10 ppmv. Depending on the design and operating conditions of the hydrogen production process, the CO content of a typical reformate gas, even after the CO shift reactor may be in the range of 0.2-1.0 vol.%; this is far higher than a PEFC can tolerate. A CO management system is required to lower the CO concentration to acceptable levels. In many cases, the CO purification system consists of a combination of physical or chemical processes to achieve the necessary reduction in CO content. A promising alternative for hydrogen purification is a combined process consisting of a carbon dioxide scrubber with subsequent methanation to reduce the carbon monoxide content to an acceptable level of less than 10 ppmv.

  18. Chitosan-based nanoparticles for survivin targeted siRNA delivery in breast tumor therapy and preventing its metastasis.

    Science.gov (United States)

    Sun, Ping; Huang, Wei; Jin, Mingji; Wang, Qiming; Fan, Bo; Kang, Lin; Gao, Zhonggao

    Nanoparticle-mediated small interfering RNA (siRNA) delivery is a promising therapeutic strategy in various cancers. However, it is difficult to deliver degradative siRNA to tumor tissue, and thus a safe and efficient vector for siRNA delivery is essential for cancer therapy. In this study, poly(ethylene glycol)-modified chitosan (PEG-CS) was synthesized successfully for delivering nucleic acid drug. We deemed that PEGylated CS could improve its solubility by forming a stable siRNA loaded in nanoparticles, and enhancing transfection efficiency of siRNA-loaded CS nanoparticles in cancer cell line. The research results showed that siRNA loaded in PEGylated CS (PEG-CS/siRNA) nanoparticles with smaller particle size had superior structural stability in the physical environment compared to CS nanoparticles. The data of in vitro antitumor activity revealed that 4T1 tumor cell growth was significantly inhibited and cellular uptake of PEG-CS/siRNA nanoparticles in 4T1 cells was dramatically enhanced compared to naked siRNA groups. The results from flow cytometry and confocal laser scanning microscopy showed that PEG-CS/siRNA nanoparticles were more easily taken up than naked siRNA. Importantly, PEG-CS/siRNA nanoparticles significantly reduced the growth of xenograft tumors of 4T1 cells in vivo. It has been demonstrated that the PEG-CS is a safe and efficient vector for siRNA delivery, and it can effectively reduce tumor growth and prevent metastasis.

  19. Biocompatible and colloidally stabilized mPEG-PE/calcium phosphate hybrid nanoparticles loaded with siRNAs targeting tumors

    OpenAIRE

    Gao, Pei; Zhang, Xiangyu; Wang, Hongzhi; Zhang, Qinghong; Li, He; Li, Yaogang; Duan, Yourong

    2015-01-01

    Calcium phosphate nanoparticles are safe and effective delivery vehicles for small interfering RNA (siRNA), as a result of their excellent biocompatibility. In this work, mPEG-PE (polyethylene glycol-L-?-phosphatidylethanolamine) was synthesized and used to prepare nanoparticles composed of mPEG-PE and calcium phosphate for siRNA delivery. Calcium phosphate and mPEG-PE formed the stable hybrid nanoparticles through self-assembly resulting from electrostatic interaction in water. The average s...

  20. Combination siRNA therapy against feline coronavirus can delay the emergence of antiviral resistance in vitro.

    Science.gov (United States)

    McDonagh, Phillip; Sheehy, Paul A; Norris, Jacqueline M

    2015-03-23

    Virulent biotypes of feline coronavirus (FCoV), commonly referred to as feline infectious peritonitis virus (FIPV), can result in the development of feline infectious peritonitis (FIP), a typically fatal immune mediated disease for which there is currently no effective antiviral treatment. We previously reported the successful in vitro inhibition of FIPV replication by synthetic siRNA mediated RNA interference (RNAi) in an immortalised cell line (McDonagh et al., 2011). A major challenge facing the development of any antiviral strategy is that of resistance, a problem which is particularly acute for RNAi based therapeutics due to the exquisite sequence specificity of the targeting mechanism. The development of resistance during treatment can be minimised using combination therapy to raise the genetic barrier or using highly potent compounds which result in a more rapid and pronounced reduction in the viral replication rate, thereby reducing the formation of mutant, and potentially resistant viruses. This study investigated the efficacy of combination siRNA therapy and its ability to delay or prevent viral escape. Virus serially passaged through cells treated with a single or dual siRNAs rapidly acquired resistance, with mutations identified in the siRNA target sites. Combination therapy with three siRNA prevented viral escape over the course of five passages. To identify more potent silencing molecules we also compared the efficacy, in terms of potency and duration of action, of canonical versus Dicer-substrate siRNAs for two previously identified effective viral motifs. Dicer-substrate siRNAs showed equivalent or better potency than canonical siRNAs for the target sites investigated, and may be a more appropriate molecule for in vivo use. Combined, these data inform the potential therapeutic application of antiviral RNAi against FIPV. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Utilization of unlocked nucleic acid (UNA) to enhance siRNA performance in vitro and in vivo

    DEFF Research Database (Denmark)

    Laursen, Maria B; Pakula, Malgorzata M; Gao, Shan

    2010-01-01

    Small interfering RNAs (siRNAs) are now established as a favourite tool to reduce gene expression by RNA interference (RNAi) in mammalian cell culture. However, limitations in potency, duration, delivery and specificity of the gene knockdown (KD) are still major obstacles that need further addres...... in a xenograft model of human pancreas cancer. Hereby UNA constitutes an important type of chemical modification for future siRNA designs....

  2. Dose-ranging evaluation of intravitreal siRNA PF-04523655 for diabetic macular edema (the DEGAS study)

    DEFF Research Database (Denmark)

    Nguyen, Quan Dong; Schachar, Ronald A; Nduaka, Chudy I

    2012-01-01

    To evaluate the safety and efficacy of three doses of PF-04523655, a 19-nucleotide methylated double stranded siRNA targeting the RTP801 gene, for the treatment of diabetic macular edema (DME) compared to focal/grid laser photocoagulation.......To evaluate the safety and efficacy of three doses of PF-04523655, a 19-nucleotide methylated double stranded siRNA targeting the RTP801 gene, for the treatment of diabetic macular edema (DME) compared to focal/grid laser photocoagulation....

  3. Exploiting interfacial water properties for desalination and purification applications.

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Hongwu (Los Alamos National Laboratory, Los Alamos, NM); Varma, Sameer; Nyman, May Devan; Alam, Todd Michael; Thuermer, Konrad; Holland, Gregory P.; Leung, Kevin; Liu, Nanguo (University of New Mexico Albuquerque, NM); Xomeritakis, George K. (University of New Mexico Albuquerque, NM); Frankamp, Benjamin L.; Siepmann, J. Ilja (University of Minnesota, Minneapolis, MN); Cygan, Randall Timothy; Hartl, Monika A. (Los Alamos National Laboratory, Los Alamos, NM); Travesset, Alex (Iowa State University, Ames, IA); Anderson, Joshua A. (Iowa State University, Ames, IA); Huber, Dale L.; Kissel, David J. (University of New Mexico Albuquerque, NM); Bunker, Bruce Conrad; Lorenz, Christian Douglas; Major, Ryan C. (University of Minnesota, Minneapolis, MN); McGrath, Matthew J. (University of Minnesota, Minneapolis, MN); Farrow, Darcie; Cecchi, Joseph L. (University of New Mexico Albuquerque, NM); van Swol, Frank B.; Singh, Seema; Rempe, Susan B.; Brinker, C. Jeffrey; Clawson, Jacalyn S.; Feibelman, Peter Julian; Houston, Jack E.; Crozier, Paul Stewart; Criscenti, Louise Jacqueline; Chen, Zhu (University of New Mexico Albuquerque, NM); Zhu, Xiaoyang (University of Minnesota, Minneapolis, MN); Dunphy, Darren Robert (University of New Mexico Albuquerque, NM); Orendorff, Christopher J.; Pless, Jason D.; Daemen, Luke L. (Los Alamos National Laboratory, Los Alamos, NM); Gerung, Henry (University of New Mexico Albuquerque, NM); Ockwig, Nathan W.; Nenoff, Tina Maria; Jiang, Ying-Bing; Stevens, Mark Jackson

    2008-09-01

    A molecular-scale interpretation of interfacial processes is often downplayed in the analysis of traditional water treatment methods. However, such an approach is critical for the development of enhanced performance in traditional desalination and water treatments. Water confined between surfaces, within channels, or in pores is ubiquitous in technology and nature. Its physical and chemical properties in such environments are unpredictably different from bulk water. As a result, advances in water desalination and purification methods may be accomplished through an improved analysis of water behavior in these challenging environments using state-of-the-art microscopy, spectroscopy, experimental, and computational methods.

  4. Simplified riboprobe purification using translucent straws as gel tubes.

    Science.gov (United States)

    Kol, S; Ben-Shlomo, I; Adashi, E Y; Rohan, R M

    1996-01-01

    Gel purification of radioactive riboprobes enhances the quality of the ribonuclease protection assay. A simple and effective method for riboprobe purification is described. The method uses acrylamide gels in plastic tubes to achieve electrophoretic separation of the RNA polymerase products.

  5. Synthesis Gas Purification Purification des gaz de synthèse

    Directory of Open Access Journals (Sweden)

    Chiche D.

    2013-10-01

    Full Text Available Fischer-Tropsch (FT based B-XTL processes are attractive alternatives for future energy production. These processes aim at converting lignocellulosic biomass possibly in co-processing with petcoke, coal, or vacuum residues into synthetic biofuels. A gasification step converts the feed into a synthesis gas (CO and H2 mixture , which undergoes the Fischer-Tropsch reaction after H2/CO ratio adjustment and CO2 removal. However synthesis gas also contains various impurities that must be removed in order to prevent Fischer-Tropsch catalyst poisoning. Due to the large feedstocks variety that can be processed, significant variations of the composition of the synthesis gas are expected. Especially, this affects the nature of the impurities that are present (element, speciation, as well as their relative contents. Moreover, due to high FT catalyst sensitivity, severe syngas specifications regarding its purity are required. For these reasons, synthesis gas purification constitutes a major challenge for the development of B-XTL processes. In this article, we focus on these major hurdles that have to be overcome. The different kinds of syngas impurities are presented. The influence of the nature of feedstocks, gasification technology and operating conditions on the type and content of impurities is discussed. Highlight is given on the fate of sulfur compounds, nitrogen compounds, halides, transition and heavy metals. Main synthesis gas purification technologies (based on adsorption, absorption, catalytic reactions, etc. are finally described, as well as the related challenges. Les procédés de synthèse de biocarburants par voie Fischer-Tropsch (FT, voies B-XTL, représentent des alternatives prometteuses pour la production d’énergie. Ces procédés permettent la conversion en carburants de synthèse de biomasse lignocellulosique, éventuellement mise en oeuvre en mélange avec des charges fossiles telles que petcoke, charbons ou résidus sous vide. Pour

  6. Plasmid pVAX1-NH36 purification by membrane and bead perfusion chromatography.

    Science.gov (United States)

    Franco-Medrano, Diana Ivonne; Guerrero-Germán, Patricia; Montesinos-Cisneros, Rosa María; Ortega-López, Jaime; Tejeda-Mansir, Armando

    2017-03-01

    The demand for plasmid DNA (pDNA) has increased in response to the rapid advances in vaccines applications to prevent and treat infectious diseases caused by virus, bacteria or parasites, such as Leishmania species. The immunization protocols require large amounts of supercoiled plasmid DNA (sc-pDNA) challenging the development of efficient and profitable processes for capturing and purified pDNA molecules from large volumes of lysates. A typical bioprocess involves four steps: fermentation, primary recovery, intermediate recovery and final purification. Ion-exchange chromatography is one of the key operations in the purification schemes of pDNA owing the chemical structure of these macromolecules. The goal of this research was to compare the performance of the final purification step of pDNA using ion-exchange chromatography on columns packed with Mustang Q membranes or perfusive beads POROS 50 HQ. The experimental results showed that both matrixes could separate the plasmid pVAX1-NH36 (3936 bp) from impurities in clarified Escherichia coli lysates with an adequate resolution. In addition, a 24- and 21-fold global purification factor was obtained. An 88 and 63% plasmid recuperation was achieved with ion-exchange membranes and perfusion beads, respectively. A better understanding of perfusion-based matrices for the purification of pDNA was developed in this research.

  7. Automated genomic DNA purification options in agricultural applications using MagneSil paramagnetic particles

    Science.gov (United States)

    Bitner, Rex M.; Koller, Susan C.

    2002-06-01

    The automated high throughput purification of genomic DNA form plant materials can be performed using MagneSil paramagnetic particles on the Beckman-Coulter FX, BioMek 2000, and the Tecan Genesis robot. Similar automated methods are available for DNA purifications from animal blood. These methods eliminate organic extractions, lengthy incubations and cumbersome filter plates. The DNA is suitable for applications such as PCR and RAPD analysis. Methods are described for processing traditionally difficult samples such as those containing large amounts of polyphenolics or oils, while still maintaining a high level of DNA purity. The robotic protocols have ben optimized for agricultural applications such as marker assisted breeding, seed-quality testing, and SNP discovery and scoring. In addition to high yield purification of DNA from plant samples or animal blood, the use of Promega's DNA-IQ purification system is also described. This method allows for the purification of a narrow range of DNA regardless of the amount of additional DNA that is present in the initial sample. This simultaneous Isolation and Quantification of DNA allows the DNA to be used directly in applications such as PCR, SNP analysis, and RAPD, without the need for separate quantitation of the DNA.

  8. Smart polymeric nanoparticles with pH-responsive and PEG-detachable properties for co-delivering paclitaxel and survivin siRNA to enhance antitumor outcomes

    Directory of Open Access Journals (Sweden)

    Jin M

    2018-04-01

    Full Text Available Mingji Jin,1 Guangming Jin,2 Lin Kang,1 Liqing Chen,1 Zhonggao Gao,1 Wei Huang11State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; 2Department of Diagnostic Radiology 2, Yanbian University Hospital, Yanji, Jilin, China Background: The co-delivery of chemotherapeutic agents and small interfering RNA (siRNA within one cargo can enhance the anticancer outcomes through its synergistic therapeutic effects. Materials and methods: We prepared smart polymeric nanoparticles (NPs with pH-responsive and poly(ethylene glycol (PEG-detachable properties to systemically co-deliver paclitaxel (PTX and siRNA against survivin gene for lung cancer therapy. The cationic polyethyleneimine-block-polylactic acid (PEI-PLA was first synthesized and characterized, with good biocompatibility. PTX was encapsulated into the hydrophobic core of the PEI-PLA polymers by dialysis, and then the survivin siRNA was loaded onto the PTX-loaded NPs (PEI-PLA/PTX through electrostatic interaction between siRNA and PEI block. Finally, the negatively charged poly(ethylene glycol-block-poly(l-aspartic acid sodium salt (PEG-PAsp was coated onto the surface of NPs by electrostatic interaction to form final smart polymeric NPs with mean particle size of 82.4 nm and zeta potential of 4.1 mV. After uptake of NPs by tumor cells, the PEG-PAsp segments became electrically neutral owing to the lower endosome pH and consequently detached from the smart NPs. This process allowed endosomal escape of the NPs through the proton-sponge effect of the exposed PEI moiety. Results: The resulting NPs achieved drug loading of 6.04 wt% and exhibited good dispersibility within 24 h in 10% fetal bovine serum (FBS. At pH 5.5, the NPs presented better drug release and cellular uptake than at pH 7.4. The NPs with survivin siRNA effectively knocked down the expression of

  9. Low-weight polyethylenimine cross-linked 2-hydroxypopyl-ß-cyclodextrin and folic acid as an efficient and nontoxic siRNA carrier for gene silencing and tumor inhibition by VEGF siRNA

    Directory of Open Access Journals (Sweden)

    Li JM

    2013-06-01

    Full Text Available Jin-Ming Li, Yuan-Yuan Wang, Wei Zhang, Hua Su, Liang-Nian Ji, Zong-Wan Mao MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, People's Republic of China Background: Targeted delivery of small interfering RNA (siRNA has been regarded as one of the most important technologies for the development of siRNA therapeutics. However, the need for safe and efficient delivery systems is a barrier to further development of RNA interference therapeutics. In this work, a nontoxic and efficient siRNA carrier delivery system of low molecular weight polyethyleneimine (PEI-600 Da cross-linked with 2-hydroxypopyl-β-cyclodextrin (HP-β-CD and folic acid (FA was synthesized for biomedical application. Methods: The siRNA carrier was prepared using a simple method and characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy. The siRNA carrier nanoparticles were characterized in terms of morphology, size and zeta potential, stability, efficiency of delivery, and gene silencing efficiency in vitro and in vivo. Results: The siRNA carrier was synthesized successfully. It showed good siRNA binding capacity and ability to protect siRNA. Further, the toxicity of the carrier measured in vitro and in vivo appeared to be negligible, probably because of degradation of the low molecular weight PEI and HP-β-CD in the cytosol. Flow cytometry and confocal microscopy confirmed that the FA receptor-mediated endocytosis of the FA-HP-β-CD-PEI/siRNA complexes was greater than that of the HP-β-CD-PEI/siRNA complexes in FA receptor-enriched HeLa cells. The FA-HP-β-CD-PEI/siRNA complexes also demonstrated excellent gene silencing efficiency in vitro (in the range of 90%, and reduced vascular endothelial growth factor (VEGF protein expression in the presence of 20% serum. FA-HP-β-CD-PEI/siRNA complexes administered via tail vein injection resulted in marked

  10. Designing optimal bioethanol networks with purification for integrated biorefineries

    International Nuclear Information System (INIS)

    Shenoy, Akshay U.; Shenoy, Uday V.

    2014-01-01

    Highlights: • An analytical method is devised for bioethanol network integration with purification. • Minimum fresh bioethanol flow and pinch are found by the Unified Targeting Algorithm. • Optimal bioethanol networks are then synthesized by the Nearest Neighbors Algorithm. • Continuous targets and networks are developed over the purifier inlet flowrate range. • Case study of a biorefinery producing bioethanol from wheat shows large savings. - Abstract: Bioethanol networks with purification for processing pathways in integrated biorefineries are targeted and designed in this work by an analytical approach not requiring graphical constructions. The approach is based on six fundamental equations involving eight variables: two balance equations for the stream flowrate and the bioethanol load over the total network system; one equation for the above-pinch bioethanol load being picked up by the minimum fresh resource and the purified stream; and three equations for the purification unit. A solution strategy is devised by specifying the two variables associated with the purifier inlet stream. Importantly, continuous targeting is then possible over the entire purifier inlet flowrate range on deriving elegant formulae for the remaining six variables. The Unified Targeting Algorithm (UTA) is utilized to establish the minimum fresh bioethanol resource flowrate and identify the pinch purity. The fresh bioethanol resource flowrate target is shown to decrease linearly with purifier inlet flowrate provided the pinch is held by the same point. The Nearest Neighbors Algorithm (NNA) is used to methodically synthesize optimal networks matching bioethanol demands and sources. A case study of a biorefinery producing bioethanol from wheat with arabinoxylan (AX) coproduction is presented. It illustrates the versatility of the approach in generating superior practical designs with up to nearly 94% savings for integrated bioethanol networks, both with and without process

  11. Enriched Water-H{sub 2} {sup 18}O Purification to be Used in Routine {sup 18}FDG Production

    Energy Technology Data Exchange (ETDEWEB)

    Al Rayyes, A. H. [Atomic Energy Commission of Syria, Chemistry Department, Cyclotron Division, Damascus (Syrian Arab Republic)

    2009-07-01

    Oxygen-18 enriched water has been recovered from IBA (Ion Beam Applications) recovery system followed by purification and then used in the production of {sup 18}F-. The purification process has been carried out by irradiation with UV followed by a distillation under vacuum. After purification, 95% of water is recovered and organic compounds, radioisotopes, trace metals and gases are eliminated efficiently. Results show that there are no significant differences in (2-deoxy-2-[{sup 18}F]fluoro-D-glucose ([{sup 18}F]FDG) production yield using purified water by the proposed method and new enriched water. Tritium was detected in the irradiated enriched water. Contamination precautions during purification should be considered. Tritium was not present in {sup 18}FDG or Na-{sup 18}F final products. (author)

  12. 21 CFR 876.5665 - Water purification system for hemodialysis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Water purification system for hemodialysis. 876... SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5665 Water purification system for hemodialysis. (a) Identification. A water purification system for hemodialysis is a...

  13. An analysis of main factors in electron beam flue gas purification

    International Nuclear Information System (INIS)

    Zhang Ming; Xu Guang

    2003-01-01

    Electron beam flue gas purification method is developing very quickly in recent years. Based on the experiment setting for electron beam flue gas purification in Institute of Nuclear Energy and Technology, Tsinghua University, how the technique factors affect the ratio of desulphurization and denitrogenation are described. Radiation dose (D), temperature (T), humidity (H), pour ammonia quantity (α) and initial concentration of SO 2 (C SO 2 ) and NO x (C NO x ) are main factors influencing flue gas purification. Using the methods of correlation analysis and regression analysis, the primary effect factors are found out and the regression equations are set to optimize the system process, predigest the system structure and to forecast the experimental results. (authors)

  14. Proposal of the system for the biogas purification using vitreous and natural zeolite membranes

    International Nuclear Information System (INIS)

    Ortega Viera, Lianys; Fernández SantanI, Elina; Alfonso Martínez, Félix Enrique; Aguiar RoqueI, Yania; Rodríguez Muñoz, Susana

    2017-01-01

    One way to reduce the effects of climate change is to replace fossil fuels with renewable energy such as biogas, but the amount of hydrogen sulphide in it represents an impediment to its use, because of its negative impacts on human health, materials of construction and the environment, being essential its reduction or elimination. For this reason, it was defined as aim to propose an effective method for the purification of biogas using membranes constructed from vitreous waste materials and natural cuban zeolite. This treatment requires four membranes with their supports and eight valves and could be used by small farmers for the purification of 1.4 m 3 of biogas per day, an amount necessary for the cooking of three meals of a family of five people, being the cost of the biogas purification process equal to 0.06%/m 3 . (author)

  15. [Purification of arsenic-binding proteins in hamster plasma after oral administration of arsenite].

    Science.gov (United States)

    Wang, Wenwen; Zhang, Min; Li, Chunhui; Qin, Yingjie; Hua, Naranmandura

    2013-01-01

    To purify the arsenic-binding proteins (As-BP) in hamster plasma after a single oral administration of arsenite (iAs(III)). Arsenite was given to hamsters in a single dose. Three types of HPLC columns, size exclusion, gel filtration and anion exchange columns, combined with an inductively coupled argon plasma mass spectrometer (ICP MS) were used to purify the As-BP in hamster plasma. SDS-PAGE was used to confirm the arsenic-binding proteins at each purification step. The three-step purification process successfully separated As-BP from other proteins (ie, arsenic unbound proteins) in hamster plasma. The molecular mass of purified As-BP in plasma was approximately 40-50 kD on SDS-PAGE. The three-step purification method is a simple and fast approach to purify the As-BP in plasma samples.

  16. Modeling Xenon Purification Systems in a Laser Inertial Fusion Engine

    Science.gov (United States)

    Hopkins, Ann; Gentile, Charles

    2011-10-01

    A Laser Inertial Fusion Engine (LIFE) is a proposed method to employ fusion energy to produce electricity for consumers. However, before it can be built and used as such, each aspect of a LIFE power plant must first be meticulously planned. We are in the process of developing and perfecting models for an exhaust processing and fuel recovery system. Such a system is especially essential because it must be able to recapture and purify expensive materials involved in the reaction so they may be reused. One such material is xenon, which is to be used as an intervention gas in the target chamber. Using Aspen HYSYS, we have modeled several subsystems for exhaust processing, including a subsystem for xenon recovery and purification. After removing hydrogen isotopes using lithium bubblers, we propose to use cryogenic distillation to purify the xenon from remaining contaminants. Aspen HYSYS allows us to analyze predicted flow rates, temperatures, pressures, and compositions within almost all areas of the xenon purification system. Through use of Aspen models, we hope to establish that we can use xenon in LIFE efficiently and in a practical manner.

  17. Impact of target mRNA structure on siRNA silencing efficiency: A large-scale study.

    Science.gov (United States)

    Gredell, Joseph A; Berger, Angela K; Walton, S Patrick

    2008-07-01

    The selection of active siRNAs is generally based on identifying siRNAs with certain sequence and structural properties. However, the efficiency of RNA interference has also been shown to depend on the structure of the target mRNA, primarily through studies using exogenous transcripts with well-defined secondary structures in the vicinity of the target sequence. While these studies provide a means for examining the impact of target sequence and structure independently, the predicted secondary structures for these transcripts are often not reflective of structures that form in full-length, native mRNAs where interactions can occur between relatively remote segments of the mRNAs. Here, using a combination of experimental results and analysis of a large dataset, we demonstrate that the accessibility of certain local target structures on the mRNA is an important determinant in the gene silencing ability of siRNAs. siRNAs targeting the enhanced green fluorescent protein were chosen using a minimal siRNA selection algorithm followed by classification based on the predicted minimum free energy structures of the target transcripts. Transfection into HeLa and HepG2 cells revealed that siRNAs targeting regions of the mRNA predicted to have unpaired 5'- and 3'-ends resulted in greater gene silencing than regions predicted to have other types of secondary structure. These results were confirmed by analysis of gene silencing data from previously published siRNAs, which showed that mRNA target regions unpaired at either the 5'-end or 3'-end were silenced, on average, approximately 10% more strongly than target regions unpaired in the center or primarily paired throughout. We found this effect to be independent of the structure of the siRNA guide strand. Taken together, these results suggest minimal requirements for nucleation of hybridization between the siRNA guide strand and mRNA and that both mRNA and guide strand structure should be considered when choosing candidate siRNAs

  18. siRNA inhibition of telomerase enhances the anti-cancer effect of doxorubicin in breast cancer cells

    International Nuclear Information System (INIS)

    Dong, Xuejun; Liu, Anding; Zer, Cindy; Feng, Jianguo; Zhen, Zhuan; Yang, Mingfeng; Zhong, Li

    2009-01-01

    Doxorubicin is an effective breast cancer drug but is hampered by a severe, dose-dependent toxicity. Concomitant administration of doxorubicin and another cancer drug may be able to sensitize tumor cells to the cytotoxicity of doxorubicin and lowers the therapeutic dosage. In this study, we examined the combined effect of low-dose doxorubicin and siRNA inhibition of telomerase on breast cancer cells. We found that when used individually, both treatments were rapid and potent apoptosis inducers; and when the two treatments were combined, we observed an enhanced and sustained apoptosis induction in breast cancer cells. siRNA targeting the mRNA of the protein component of telomerase, the telomerase reverse transcriptase (hTERT), was transfected into two breast cancer cell lines. The siRNA inhibition was confirmed by RT-PCR and western blot on hTERT mRNA and protein levels, respectively, and by measuring the activity level of telomerase using the TRAP assay. The effect of the hTERT siRNA on the tumorigenicity of the breast cancer cells was also studied in vivo by injection of the siRNA-transfected breast cancer cells into nude mice. The effects on cell viability, apoptosis and senescence of cells treated with hTERT siRNA, doxorubicin, and the combined treatment of doxorubicin and hTERT siRNA, were examined in vitro by MTT assay, FACS and SA-β-galactosidase staining. The hTERT siRNA effectively knocked down the mRNA and protein levels of hTERT, and reduced the telomerase activity to 30% of the untreated control. In vivo, the tumors induced by the hTERT siRNA-transfected cells were of reduced sizes, indicating that the hTERT siRNA also reduced the tumorigenic potential of the breast cancer cells. The siRNA treatment reduced cell viability by 50% in breast cancer cells within two days after transfection, while 0.5 μM doxorubicin treatment had a comparable effect but with a slower kinetics. The combination of hTERT siRNA and 0.5 μM doxorubicin killed twice as many

  19. Inefficient cationic lipid-mediated siRNA and antisense oligonucleotide transfer to airway epithelial cells in vivo

    Directory of Open Access Journals (Sweden)

    Hu Jim

    2006-02-01

    Full Text Available Abstract Background The cationic lipid Genzyme lipid (GL 67 is the current "gold-standard" for in vivo lung gene transfer. Here, we assessed, if GL67 mediated uptake of siRNAs and asODNs into airway epithelium in vivo. Methods Anti-lacZ and ENaC (epithelial sodium channel siRNA and asODN were complexed to GL67 and administered to the mouse airway epithelium in vivo Transfection efficiency and efficacy were assessed using real-time RT-PCR as well as through protein expression and functional studies. In parallel in vitro experiments were carried out to select the most efficient oligonucleotides. Results In vitro, GL67 efficiently complexed asODNs and siRNAs, and both were stable in exhaled breath condensate. Importantly, during in vitro selection of functional siRNA and asODN we noted that asODNs accumulated rapidly in the nuclei of transfected cells, whereas siRNAs remained in the cytoplasm, a pattern consistent with their presumed site of action. Following in vivo lung transfection siRNAs were only visible in alveolar macrophages, whereas asODN also transfected alveolar epithelial cells, but no significant uptake into conducting airway epithelial cells was seen. SiRNAs and asODNs targeted to β-galactosidase reduced βgal mRNA levels in the airway epithelium of K18-lacZ mice by 30% and 60%, respectively. However, this was insufficient to reduce protein expression. In an attempt to increase transfection efficiency of the airway epithelium, we increased contact time of siRNA and asODN using the in vivo mouse nose model. Although highly variable and inefficient, transfection of airway epithelium with asODN, but not siRNA, was now seen. As asODNs more effectively transfected nasal airway epithelial cells, we assessed the effect of asODN against ENaC, a potential therapeutic target in cystic fibrosis; no decrease in ENaC mRNA levels or function was detected. Conclusion This study suggests that although siRNAs and asODNs can be developed to inhibit

  20. Drying and purification of natural gas by clinoptilolite on an experimental pilot plant

    Energy Technology Data Exchange (ETDEWEB)

    Tsitsishvili, G V; Urotadze, S L; Lukin, V D; Bagirov, R M

    1976-02-01

    The paper deals with the process of the drying and purification of natural gas from CO/sub 2/ on an experimental pilot plant using the natural zeolite clinoptilolite. On the basis of the obtained data the dynamic activity of clinoptilolite against water and CO/sub 2/ has been calculated.

  1. Effects of Two Purification Pretreatments on Electroless Copper Coating over Single-Walled Carbon Nano tubes

    International Nuclear Information System (INIS)

    Zheng, Z.; Li, L.; Dong, Sh.; Li, Sh.; Xiao, A.; Sun, Sh.

    2014-01-01

    To achieve the reinforcement of copper matrix composite by single-walled carbon nano tubes, a three-step-refluxing purification of carbon nano tubes sample with HNO 3 -NaOH-HCl was proposed and demonstrated. A previously reported purification process using an electromagnetic stirring with H 2 O 2 /HCl mixture was also repeated. Then, the purified carbon nano tubes were coated with copper by the same electroless plating process. At the end, the effects of the method on carbon nano tubes themselves and on copper coating were determined by transmission electron microscope spectroscopy, scanning electron microscope spectroscopy, X-ray diffractometry, thermogravimetric analysis, Fourier transformed infrared spectroscopy, and energy dispersive spectrometry. It was clearly confirmed that both of the two processes could remove most of iron catalyst particles and carbonaceous impurities without significant damage to carbon nano tubes. The thermal stability of the sample purified by H 2 O 2 /HCl treatment was slightly higher than that purified by HNO 3 -NaOH-HCl treatment. Nevertheless, the purification by HNO 3 -NaOH-HCl treatment was more effective for carboxyl functionalization on nano tubes than that by H 2 O 2 /HCl treatment. The Cu-coating on carbon nano tubes purified by both purification processes was complete, homogenous, and continuous. However, the Cu-coating on carbon nano tubes purified by H 2 O 2 /HCl was oxidized more seriously than those on carbon nano tubes purified by HNO 3 -NaOH-HCl treatment.

  2. Separation and purification of gadolinium and others rare earths, and yttrium

    International Nuclear Information System (INIS)

    Awwal, M.A.; Filgueiras, S.A.C.

    1988-01-01

    The experimental works in laboratories for developing a solvent extraction process with the purpose of gadolinium separation and purification, and secondarily samarium, europium, lanthanum and yttrium are described. Using as solvent di-2-ethylhexylphosphoric acid (DEHPA) a preliminary flow chart for separation for these elements are developed. (author)

  3. EDF PWRs primary coolant purification strategies

    International Nuclear Information System (INIS)

    Gressier, Frederic; Mascarenhas, Darren; Taunier, Stephane; Le-Calvar, Marc; Bretelle, Jean-Luc; Ranchoux, Gilles

    2012-09-01

    In order to achieve a good physico-chemical quality of the primary coolant fluid, the primary water is continuously treated by the Chemical and Volume Control System (CVCS). This system is composed of a treatment chain containing filters and ion-exchange resins. In the EDF design, an upstream filter is placed before the resin so as to prevent it from being saturated with insoluble particles. Then, the fluid passes through several resin beds (up to 3 depending on the configuration) and again through a downstream filter that prevents resin fines dissemination into the reactor coolant. Much work has been conducted in the last 5 years on the homogenisation of products and usage on French EDF NPP primary coolant treatment, while taking into account the compromise between source term reduction, liquid and solid waste, and buying and disposal costs. Two national markets have been created, and two operational documents for chemists on site have been published: a filtration guideline and an ion-exchange resin guideline. Both documents give general information about the products used, how are they characterized and selected for national market (technical requirements, standards and tests), how they should be used and what are the change-out criteria. They are also periodically updated based on feedback from sites. The positive impact on resin and filter lifetime (extension of some, limitation of others), homogenisation of products and usage will be presented. Moreover, EDF is constantly in the process of improving the current purification methods, as well as researching the use of existing and novel technologies. In this field, recent experiments on short loading of resin during reactor shutdown has been tested on site with success. In addition, work is done on silica free filters, filter consumption and filter chemical release. An overview of these optimization methods will be given. (authors)

  4. Reduction of bilirubin by targeting human heme oxygenase-1 through siRNA.

    Science.gov (United States)

    Xia, Zhen-Wei; Li, Chun-E; Jin, You-Xin; Shi, Yi; Xu, Li-Qing; Zhong, Wen-Wei; Li, Yun-Zhu; Yu, Shan-Chang; Zhang, Zi-Li

    2007-04-01

    Neonatal hyperbilirubinemia is a common clinical condition caused mainly by the increased production and decreased excretion of bilirubin. Current treatment is aimed at reducing the serum levels of bilirubin. Heme oxygenase-1 (HO-1) is a rate-limiting enzyme that generates bilirubin. In this study we intended to suppress HO-1 using the RNA interference technique. Small interfering RNA (siRNA)-A, -B, and -C were designed based on human HO-1 (hHO-1) mRNA sequences. siRNA was transfected into a human hepatic cell line (HL-7702). hHO-1 transcription and protein levels were then determined. In addition, the inhibitory effect of siRNA on hHO-1 was assessed in cells treated with hemin or transfected with an hHO-1 plasmid. siRNA-C showed the most potent suppressive effect on hHO-1. This inhibition is dose and time dependent. Compared with control, both hemin and hHO-1 plasmids up-regulated hHO-1 expression in HL-7702 cells. However, the up-regulation was significantly attenuated by siRNA-C. Furthermore, the decrease in hHO-1 activity was coincident with the suppression of its transcription. Finally, siRNA-C was shown to reduce hHO-1 enzymatic activity and bilirubin levels. Thus, this study provides a novel therapeutic rationale by blocking bilirubin formation via siRNA for preventing and treating neonatal hyperbilirubinemia and bilirubin encephalopathy at an early clinical stage.

  5. An albumin-mediated cholesterol design-based strategy for tuning siRNA pharmacokinetics and gene silencing.

    Science.gov (United States)

    Bienk, Konrad; Hvam, Michael Lykke; Pakula, Malgorzata Maria; Dagnæs-Hansen, Frederik; Wengel, Jesper; Malle, Birgitte Mølholm; Kragh-Hansen, Ulrich; Cameron, Jason; Bukrinski, Jens Thostrup; Howard, Kenneth A

    2016-06-28

    Major challenges for the clinical translation of small interfering RNA (siRNA) include overcoming the poor plasma half-life, site-specific delivery and modulation of gene silencing. In this work, we exploit the intrinsic transport properties of human serum albumin to tune the blood circulatory half-life, hepatic accumulation and gene silencing; based on the number of siRNA cholesteryl modifications. We demonstrate by a gel shift assay a strong and specific affinity of recombinant human serum albumin (rHSA) towards cholesteryl-modified siRNA (Kd>1×10(-7)M) dependent on number of modifications. The rHSA/siRNA complex exhibited reduced nuclease degradation and reduced induction of TNF-α production by human peripheral blood mononuclear cells. The increased solubility of heavily cholesteryl modified siRNA in the presence of rHSA facilitated duplex annealing and consequent interaction that allowed in vivo studies using multiple cholesteryl modifications. A structural-activity-based screen of in vitro EGFP-silencing was used to select optimal siRNA designs containing cholesteryl modifications within the sense strand that were used for in vivo studies. We demonstrate plasma half-life extension in NMRI mice from t1/2 12min (naked) to t1/2 45min (single cholesteryl) and t1/2 71min (double cholesteryl) using fluorescent live bioimaging. The biodistribution showed increased accumulation in the liver for the double cholesteryl modified siRNA that correlated with an increase in hepatic Factor VII gene silencing of 28% (rHSA/siRNA) compared to 4% (naked siRNA) 6days post-injection. This work presents a novel albumin-mediated cholesteryl design-based strategy for tuning pharmacokinetics and systemic gene silencing. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. PEGylated carboxymethyl chitosan/calcium phosphate hybrid anionic nanoparticles mediated hTERT siRNA delivery for anticancer therapy.

    Science.gov (United States)

    Xie, Ying; Qiao, Hongzhi; Su, Zhigui; Chen, Minglei; Ping, Qineng; Sun, Minjie

    2014-09-01

    Lack of safe and effective delivery vehicle is the main obstacle for siRNA mediated cancer therapy. In this study, we synthesized a pH-sensitive polymer of PEG grafted carboxymethyl chitosan (PEG-CMCS) and developed anionic-charged hybrid nanoparticles of PEG-CMCS and calcium phosphate (CaP) for siRNA delivery through a single-step self-assembly method in aqueous condition. The formed nanoparticles with charge of around -8.25 mv and average diameter of 102.1 nm exhibited efficient siRNA encapsulation and enhanced colloidal and serum stability. The test in vitro indicated that the nanoparticles entered into HepG2 cells by endocytosis, and achieved endosomal escape of siRNA effectively due to the pH-responsive disassembly of nanoparticles and dissolution of CaP in the endosome. Reporter gene silencing assay showed that luciferase siRNA delivered by the anionic nanoparticles could achieve gene silencing efficacy comparable to that of conventional Lipofectamine 2000. Additionally, dramatic hTERT knockdown mediated by the anionic nanoparticles transfection induced significant apoptosis of HepG2 cells in vitro. After intravenous injection in tumor-bearing BALB/c nude mice, the nanoparticles specifically accumulated into tumor regions by EPR effect, leading to efficient and specific gene silencing sequentially. Most importantly, the nanoparticles carrying hTERT siRNA inhibited tumor growth significantly via silencing hTERT expression and inducing cells apoptosis in HepG2 tumor xenograft. Moreover, comprehensive safety studies of the nanoparticles confirmed their superior safety both in vitro and in vivo. We concluded that the PEG-CMCS/CaP hybrid anionic nanoparticles possessed potential as a safe and effective siRNA delivery system for anticancer therapy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Fast reactor cover gas purification - The UK position

    International Nuclear Information System (INIS)

    Thorley, A.W.

    1987-01-01

    The cover gas in the Prototype Fast Reactor (PFR) provides an inert gas blanket for both primary and secondary sodium circuits, ensures inert gas padding exists between the upper seals associated with penetrations through the reactor roof and provides argon to items of plant such as the control rods and the rotating shield and also to on line instruments such as the secondary circuit Katharometers. In order to meet these and other requirements purification of the argon cover gas is important to ensure: gas fed to purge gaps in the area of the magnetic hold device in the control rod mechanisms is not laden with sodium aerosols and reactive impurities (O 2 , H 2 ) which could cause blocking both within the gaps and pipelines; gas phase detection systems which provide early warning of steam generator failures or oil ingress into the sodium are not affected by the presence of gaseous impurities such as H 2 , CO/CO 2 and CH 4 ; mass transfer processes involving both corrosion products and interstitial atoms cannot be sustained in the cover gas environment due to the presence of high levels of O 2 , N 2 and carburising gases; background levels of radioactivity (eg Xe 133) are sufficiently low to enable gas phase detection of failed fuel pins, and the primary circuit gas blanket activity is sufficiently reduced so that discharges to the atmosphere are minimised. This paper describes how the PFR cover gas purification system is coping with these various items and how current thinking regarding the design of cover gas purification systems for a Civil Demonstration Fast Reactor (CDFR), where larger gas volumes and higher levels of radioactivity may be involved, is being guided by current experience on PFR. The paper also briefly review the experimental work planned to study aerosol and caesium behaviour in cove gas environments and discusses the behaviour of those impurities such as Zn, oil and N 2 which are potentially damaging if certain levels are exceeded in operating

  8. Fractionation for Biodiesel Purification Using Supercritical Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Chao-Yi Wei

    2014-02-01

    Full Text Available In recent years, biodegradable and alternative biodiesel has attracted increased attention worldwide. Producing biodiesel from biomass involves critical separation and purification technology. Conventional technologies such as gravitational settling, decantation, filtration, water washing, acid washing, organic solvent washing and absorbent applications are inefficient, less cost effective and environmentally less friendly. In this study supercritical carbon dioxide (SC-CO2 with few steps and a low environmental impact, was used for biodiesel fractionation from impure fatty acid methyl ester (FAME solution mixes. The method is suitable for application in a variety of biodiesel production processes requiring subsequent stages of purification. The fractionation and purification was carried out using continuous SC-CO2 fractionation equipment, consisting of three columns filled with stainless steel fragments. A 41.85% FAME content solution mix was used as the raw material in this study. Variables were a temperature range of 40–70 °C, pressure range of 10–30 MPa, SC-CO2 flow rate range of 7–21 mL/min and a retention time range of 30–90 min. The Taguchi method was used to identify optimal operating conditions. The results show that a separated FAME content of 99.94% was verified by GC-FID under optimal fractionation conditions, which are a temperature of 40 °C of, a pressure level of 30MPa and a flow rate of 7 mL/min of SC-CO2 for a retention time of 90 min.

  9. Human DMBT1-Derived Cell-Penetrating Peptides for Intracellular siRNA Delivery

    DEFF Research Database (Denmark)

    Tuttolomondo, Martina; Casella, Cinzia; Hansen, Pernille Lund

    2017-01-01

    tumor 1) is a pattern recognition molecule that interacts with polyanions and recognizes and aggregates bacteria. Taking advantage of these properties, we investigated whether specific synthetic DMBT1-derived peptides could be used to formulate nanoparticles for siRNA administration. Using......-potential, circular dichroism, dynamic light scattering, and transmission electron microscopy revealed negatively charged nanoparticles with an average diameter of 10-800 nm, depending on the reaction conditions, and a spherical or rice-shaped morphology, depending on the peptide and β-helix conformation. We...

  10. Lipoprotein-biomimetic nanostructure enables efficient targeting delivery of siRNA to Ras-activated glioblastoma cells via macropinocytosis

    Science.gov (United States)

    Huang, Jia-Lin; Jiang, Gan; Song, Qing-Xiang; Gu, Xiao; Hu, Meng; Wang, Xiao-Lin; Song, Hua-Hua; Chen, Le-Pei; Lin, Ying-Ying; Jiang, Di; Chen, Jun; Feng, Jun-Feng; Qiu, Yong-Ming; Jiang, Ji-Yao; Jiang, Xin-Guo; Chen, Hong-Zhuan; Gao, Xiao-Ling

    2017-05-01

    Hyperactivated Ras regulates many oncogenic pathways in several malignant human cancers including glioblastoma and it is an attractive target for cancer therapies. Ras activation in cancer cells drives protein internalization via macropinocytosis as a key nutrient-gaining process. By utilizing this unique endocytosis pathway, here we create a biologically inspired nanostructure that can induce cancer cells to `drink drugs' for targeting activating transcription factor-5 (ATF5), an overexpressed anti-apoptotic transcription factor in glioblastoma. Apolipoprotein E3-reconstituted high-density lipoprotein is used to encapsulate the siRNA-loaded calcium phosphate core and facilitate it to penetrate the blood-brain barrier, thus targeting the glioblastoma cells in a macropinocytosis-dependent manner. The nanostructure carrying ATF5 siRNA exerts remarkable RNA-interfering efficiency, increases glioblastoma cell apoptosis and inhibits tumour cell growth both in vitro and in xenograft tumour models. This strategy of targeting the macropinocytosis caused by Ras activation provides a nanoparticle-based approach for precision therapy in glioblastoma and other Ras-activated cancers.

  11. Purification, characterization of phytase enzyme from Lactobacillus ...

    African Journals Online (AJOL)

    Purification, characterization of phytase enzyme from Lactobacillus plantarum bacteria and determination of its kinetic properties. ... Many of the cereal grains, legumes and oilseeds store phosphorus in phytate form. Phytases can be produced by plants, animals and microorganisms. However, the ones with microbial origin ...

  12. Purification of functionalized DNA origami nanostructures.

    Science.gov (United States)

    Shaw, Alan; Benson, Erik; Högberg, Björn

    2015-05-26

    The high programmability of DNA origami has provided tools for precise manipulation of matter at the nanoscale. This manipulation of matter opens up the possibility to arrange functional elements for a diverse range of applications that utilize the nanometer precision provided by these structures. However, the realization of functionalized DNA origami still suffers from imperfect production methods, in particular in the purification step, where excess material is separated from the desired functionalized DNA origami. In this article we demonstrate and optimize two purification methods that have not previously been applied to DNA origami. In addition, we provide a systematic study comparing the purification efficacy of these and five other commonly used purification methods. Three types of functionalized DNA origami were used as model systems in this study. DNA origami was patterned with either small molecules, antibodies, or larger proteins. With the results of our work we aim to provide a guideline in quality fabrication of various types of functionalized DNA origami and to provide a route for scalable production of these promising tools.

  13. Purification and characterization of xylanase from Aspergillus ...

    African Journals Online (AJOL)

    Xylanase was subjected to a three-step purification scheme involving ammonium sulphate precipitation, gel filtration chromatography and anion exchange chromatography. Purity was verified by running the extracted protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and a single band was ...

  14. Expression, purification and characterization of the interferon ...

    Indian Academy of Sciences (India)

    2012-01-19

    Jan 19, 2012 ... utilizing a single-step affinity purification with an appreciable yield of the highly purified protein. Recombinant RNase L was characterized by SDS-PAGE, immunoblotting and MALDI-TOF analysis. A semi-quantitative agarose-gel-based ribonuclease assay was developed for measuring its 2-5A-dependent ...

  15. Purification and characterization of protease enzyme from ...

    African Journals Online (AJOL)

    user

    2013-03-20

    Mar 20, 2013 ... Full Length Research Paper. Purification and ... ting into small peptides and free amino acids, which can ... Isolated strain was cultured in synthetic medium- casein (SMC; ... Protease activity was assayed by sigma's non-specific protease ... following buffers: 0.05 M citrate-phosphate buffer (pH 5 to 6), Tris-.

  16. Purification, Characterization and Antibacterial Mechanism of ...

    African Journals Online (AJOL)

    Purpose: To carry out the extraction, purification and biological characterization, and assess the antibacterial activity of bacteriocin from Lactobacillus acidophilus XH1. Methods: Chloroform extraction method was used for bacteriocin extraction while characterization of bacteriocin was carried out by flat-dug well agar ...

  17. Expression and Purification of Sperm Whale Myoglobin

    Science.gov (United States)

    Miller, Stephen; Indivero, Virginia; Burkhard, Caroline

    2010-01-01

    We present a multiweek laboratory exercise that exposes students to the fundamental techniques of bacterial expression and protein purification through the preparation of sperm whale myoglobin. Myoglobin, a robust oxygen-binding protein, contains a single heme that gives the protein a reddish color, making it an ideal subject for the teaching…

  18. Biodiesel separation and purification: A review

    International Nuclear Information System (INIS)

    Atadashi, I.M.; Aroua, M.K.; Aziz, A. Abdul

    2011-01-01

    Biodiesel as a biodegradable, sustainable and clean energy has worldwide attracted renewed and growing interest in topical years, chiefly due to development in biodiesel fuel and ecological pressures which include climatic changes. In the production of biodiesel from biomass, separation and purification of biodiesel is a critical technology. Conventional technologies used for biodiesel separation such as gravitational settling, decantation, filtration and biodiesel purification such as water washing, acid washing, and washing with ether and absorbents have proven to be inefficient, time and energy consumptive, and less cost effective. The involvement of membrane reactor and separative membrane shows great promise for the separation and purification of biodiesel. Membrane technology needs to be explored and exploited to overcome the difficulties usually encountered in the separation and purification of biodiesel. In this paper both conventional and most recent membrane technologies used in refining biodiesel have been critically reviewed. The effects of catalysts, free fatty acids, water content and oil to methanol ratios on the purity and quality of biodiesel are also examined. (author)

  19. Zone distillation: a new purification method

    International Nuclear Information System (INIS)

    Kravchenko, A.I.

    2011-01-01

    The features of zone distillation (with zone melting of refined material and with pulling of condensate) as a new purification method are shown. The method is based on similarity of equations of distillation and crystallization refining. The analogy between some distillation and condensation methods (particularly between zone distillation and zone recrystallization) is should up

  20. [Study on extraction and purification technology of Hubei ophiopogon saponins].

    Science.gov (United States)

    Lin, Yun-Han; Li, Chong-Ming; Li, Xiao-Dong; Xiang, Yang; Zhang, Ya-Qin; Zhang, Xiao-Cun; Liu, Xia

    2013-05-01

    To explore the extraction and purification technology of total saponins from the effective parts of Liriope spicata. Orthogonal design was used. Macroporous resin was selected to separate and purify total saponin from the effective parts of Liriope spicata. The process validation was conducted. The total saponins was determined by Ultraviolet Spectrophotometry. The optimal extraction conditions were as follows: 10 times the amount of ethanol (70%) for each occasion and hot reflux (3 x 2 h). Total saponins was purified by D101 macroporous resin. The concentration of eluting ethanol was 50% - 70%. Ethanol (70%) was selected as the best eluent. The result of process validation was consistent with the study. The process is simple and stable enough to significantly improve the extraction rate of the effective parts. The study can provide reference for the research and production of effective parts of traditional Chinese medicine such as Liriope spicata.