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Nguyen BH, Takahashi CN, Gupta G, Smith JA, Rouse R, Berndt P, Yekhanin S, Ward DP, Ang SD, Garvan P, Parker HY, Carlson R, Carmean D, Ceze L, Strauss K. Scaling DNA data storage with nanoscale electrode wells. Sci Adv 2021; 7:eabi6714. [PMID: 34818035 PMCID: PMC8612674 DOI: 10.1126/sciadv.abi6714] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 10/05/2021] [Indexed: 05/21/2023]
Abstract
Synthetic DNA is an attractive medium for long-term data storage because of its density, ease of copying, sustainability, and longevity. Recent advances have focused on the development of new encoding algorithms, automation, preservation, and sequencing technologies. Despite progress in these areas, the most challenging hurdle in deployment of DNA data storage remains the write throughput, which limits data storage capacity. We have developed the first nanoscale DNA storage writer, which we expect to scale DNA write density to 25 × 106 sequences per square centimeter, three orders of magnitude improvement over existing DNA synthesis arrays. We show confinement of DNA synthesis to an area under 1 square micrometer, parallelized over millions of nanoelectrode wells and then successfully write and decode a message in DNA. DNA synthesis on this scale will enable write throughputs to reach megabytes per second and is a key enabler to a practical DNA data storage system.
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Affiliation(s)
- Bichlien H. Nguyen
- Microsoft Research, Redmond, WA, USA
- Paul G. Allen School of Computer Science and Engineering, University of Washington, Seattle, WA, USA
- Corresponding author. (B.H.N.); (K.S.)
| | - Christopher N. Takahashi
- Paul G. Allen School of Computer Science and Engineering, University of Washington, Seattle, WA, USA
| | | | - Jake A. Smith
- Microsoft Research, Redmond, WA, USA
- Paul G. Allen School of Computer Science and Engineering, University of Washington, Seattle, WA, USA
| | | | | | | | - David P. Ward
- Paul G. Allen School of Computer Science and Engineering, University of Washington, Seattle, WA, USA
| | | | | | | | | | | | - Luis Ceze
- Microsoft Research, Redmond, WA, USA
- Paul G. Allen School of Computer Science and Engineering, University of Washington, Seattle, WA, USA
| | - Karin Strauss
- Microsoft Research, Redmond, WA, USA
- Paul G. Allen School of Computer Science and Engineering, University of Washington, Seattle, WA, USA
- Corresponding author. (B.H.N.); (K.S.)
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Ward DP, Hewitson P, Cárdenas-Fernández M, Hamley-Bennett C, Díaz-Rodríguez A, Douillet N, Adams JP, Leak DJ, Ignatova S, Lye GJ. Centrifugal partition chromatography in a biorefinery context: Optimisation and scale-up of monosaccharide fractionation from hydrolysed sugar beet pulp. J Chromatogr A 2017; 1497:56-63. [PMID: 28366567 DOI: 10.1016/j.chroma.2017.03.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/28/2017] [Accepted: 03/03/2017] [Indexed: 11/16/2022]
Abstract
The isolation of component sugars from biomass represents an important step in the bioprocessing of sustainable feedstocks such as sugar beet pulp. Centrifugal partition chromatography (CPC) is used here, as an alternative to multiple resin chromatography steps, to fractionate component monosaccharides from crude hydrolysed sugar beet pulp pectin. CPC separation of samples, prepared in the stationary phase, was carried out using an ethanol: ammonium sulphate (300gL-1) phase system (0.8:1.8v:v) in ascending mode. This enabled removal of crude feedstream impurities and separation of monosaccharides into three fractions (l-rhamnose, l-arabinose and d-galactose, and d-galacturonic acid) in a single step. Throughput was improved three-fold by increasing sample injection volume, from 4 to 16% of column volume, with similar separation performance maintained in all cases. Extrusion of the final galacturonic acid fraction increased the eluted solute concentration, reduced the total separation time by 24% and removed the need for further column regeneration. Reproducibility of the separation after extrusion was validated by using multiple stacked injections. Scale-up was performed linearly from a semi-preparative 250mL column to a preparative 950mL column with a scale-up ratio of 3.8 applied to mobile phase flow rate and sample injection volume. Throughputs of 9.4gL-1h-1 of total dissolved solids were achieved at the preparative scale with a throughput of 1.9gL-1h-1 of component monosaccharides. These results demonstrate the potential of CPC for both impurity removal and target fractionation within biorefinery separations.
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Affiliation(s)
- David P Ward
- The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, UK
| | - Peter Hewitson
- Advanced Bioprocessing Centre, Department of Mechanical, Aerospace & Civil Engineering, Brunel University London, Uxbridge UB8 3PH, UK
| | - Max Cárdenas-Fernández
- The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, UK
| | | | - Alba Díaz-Rodríguez
- GlaxoSmithKline R&D Ltd., Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, UK
| | - Nathalie Douillet
- GlaxoSmithKline R&D Ltd., Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, UK
| | - Joseph P Adams
- GlaxoSmithKline R&D Ltd., Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, UK
| | - David J Leak
- Department of Biology and Biochemistry, University of Bath, Bath, Somerset BA2 7AY, UK
| | - Svetlana Ignatova
- Advanced Bioprocessing Centre, Department of Mechanical, Aerospace & Civil Engineering, Brunel University London, Uxbridge UB8 3PH, UK.
| | - Gary J Lye
- The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, UK.
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Cárdenas-Fernández M, Bawn M, Hamley-Bennett C, Bharat PKV, Subrizi F, Suhaili N, Ward DP, Bourdin S, Dalby PA, Hailes HC, Hewitson P, Ignatova S, Kontoravdi C, Leak DJ, Shah N, Sheppard TD, Ward JM, Lye GJ. An integrated biorefinery concept for conversion of sugar beet pulp into value-added chemicals and pharmaceutical intermediates. Faraday Discuss 2017; 202:415-431. [DOI: 10.1039/c7fd00094d] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Over 8 million tonnes of sugar beet are grown annually in the UK. Sugar beet pulp (SBP) is the main by-product of sugar beet processing which is currently dried and sold as a low value animal feed. SBP is a rich source of carbohydrates, mainly in the form of cellulose and pectin, including d-glucose (Glu), l-arabinose (Ara) and d-galacturonic acid (GalAc). This work describes the technical feasibility of an integrated biorefinery concept for the fractionation of SBP and conversion of these monosaccharides into value-added products. SBP fractionation is initially carried out by steam explosion under mild conditions to yield soluble pectin and insoluble cellulose fractions. The cellulose is readily hydrolysed by cellulases to release Glu that can then be fermented by a commercial yeast strain to produce bioethanol at a high yield. The pectin fraction can be either fully hydrolysed, using physico-chemical methods, or selectively hydrolysed, using cloned arabinases and galacturonases, to yield Ara-rich and GalAc-rich streams. These monomers can be separated using either Centrifugal Partition Chromatography (CPC) or ultrafiltration into streams suitable for subsequent enzymatic upgrading. Building on our previous experience with transketolase (TK) and transaminase (TAm) enzymes, the conversion of Ara and GalAc into higher value products was explored. In particular the conversion of Ara into l-gluco-heptulose (GluHep), that has potential therapeutic applications in hypoglycaemia and cancer, using a mutant TK is described. Preliminary studies with TAm also suggest GluHep can be selectively aminated to the corresponding chiral aminopolyol. The current work is addressing the upgrading of the remaining SBP monomer, GalAc, and the modelling of the biorefinery concept to enable economic and Life Cycle Analysis (LCA).
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Ward DP, Cárdenas-Fernández M, Hewitson P, Ignatova S, Lye GJ. Centrifugal partition chromatography in a biorefinery context: Separation of monosaccharides from hydrolysed sugar beet pulp. J Chromatogr A 2015; 1411:84-91. [PMID: 26278358 DOI: 10.1016/j.chroma.2015.08.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Revised: 07/29/2015] [Accepted: 08/03/2015] [Indexed: 11/30/2022]
Abstract
A critical step in the bioprocessing of sustainable biomass feedstocks, such as sugar beet pulp (SBP), is the isolation of the component sugars from the hydrolysed polysaccharides. This facilitates their subsequent conversion into higher value chemicals and pharmaceutical intermediates. Separation methodologies such as centrifugal partition chromatography (CPC) offer an alternative to traditional resin-based chromatographic techniques for multicomponent sugar separations. Highly polar two-phase systems containing ethanol and aqueous ammonium sulphate are examined here for the separation of monosaccharides present in hydrolysed SBP pectin: l-rhamnose, l-arabinose, d-galactose and d-galacturonic acid. Dimethyl sulfoxide (DMSO) was selected as an effective phase system modifier improving monosaccharide separation. The best phase system identified was ethanol:DMSO:aqueous ammonium sulphate (300gL(-1)) (0.8:0.1:1.8, v:v:v) which enabled separation of the SBP monosaccharides by CPC (200mL column) in ascending mode (upper phase as mobile phase) with a mobile phase flow rate of 8mLmin(-1). A mixture containing all four monosaccharides (1.08g total sugars) in the proportions found in hydrolysed SBP was separated into three main fractions; a pure l-rhamnose fraction (>90%), a mixed l-arabinose/d-galactose fraction and a pure d-galacturonic acid fraction (>90%). The separation took less than 2h demonstrating that CPC is a promising technique for the separation of these sugars with potential for application within an integrated, whole crop biorefinery.
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Affiliation(s)
- David P Ward
- The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Gordon Street, London WC1H 0AH, UK
| | - Max Cárdenas-Fernández
- The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Gordon Street, London WC1H 0AH, UK
| | - Peter Hewitson
- Institute of Environment, Health and Societies, Brunel University, Uxbridge UB8 3PH, UK
| | - Svetlana Ignatova
- Institute of Environment, Health and Societies, Brunel University, Uxbridge UB8 3PH, UK.
| | - Gary J Lye
- The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Gordon Street, London WC1H 0AH, UK.
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Eriksson BI, Dahl OE, Lassen MR, Ward DP, Rothlein R, Davis G, Turpie AGG. Partial factor IXa inhibition with TTP889 for prevention of venous thromboembolism: an exploratory study. J Thromb Haemost 2008; 6:457-63. [PMID: 18088349 DOI: 10.1111/j.1538-7836.2007.02872.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Inhibitors of factor (F) IXa show potent antithrombotic activity with a low risk of bleeding in preclinical models. We investigated the anticoagulant potential of oral TTP889, a small molecule that inhibits up to 90% of FIXa activity at therapeutic doses, using a clinical model of extended prophylaxis in hip fracture surgery (HFS). METHODS In this multicenter, randomized, double-blind study, 261 patients received oral TTP889 (300 mg once daily) or placebo starting 6-10 days after HFS, and standard thromboprophylaxis for 5-9 days. Treatment was continued for 3 weeks and all patients then underwent mandatory bilateral venography. The primary efficacy outcome was venous thromboembolism (VTE; venographic or symptomatic deep vein thrombosis or pulmonary embolism) during treatment, and it was evaluated centrally by an independent adjudication panel. The main safety outcome was bleeding (major, clinically relevant non-major, and minor events). RESULTS Two hundred and twelve patients with an evaluable venogram were included in the efficacy analysis. The primary efficacy outcome occurred in 32.1% (35/109) of patients who had been allocated TTP889, and 28.2% (29/103) of patients on placebo (P = 0.58). There were no major bleeding events, and only two clinically relevant non-major bleeding events with TTP889. CONCLUSION Partial FIXa inhibition with TTP889 300 mg daily was not effective for extended prevention of VTE after standard prophylaxis for up to 9 days. Coupled with the low incidence of bleeding episodes, this suggests a lack of antithrombotic potential. Further investigation of TTP889 in different clinical settings is needed. (Clinical trial registration information URL: http://www.clinicaltrials.gov. Unique identifier: NCT00119457).
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Affiliation(s)
- B I Eriksson
- Sahlgrenska University Hospital/Ostra, Göteborg, Sweden.
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McKee RH, Kapp RW, Ward DP. Evaluation of the systemic toxicity of coal liquefaction-derived materials following repeated dermal exposure in the rabbit. J Appl Toxicol 1985; 5:345-51. [PMID: 4078215 DOI: 10.1002/jat.2550050602] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The subchronic toxicity of two materials produced by the EDS direct coal liquefaction process was investigated using adult New Zealand white rabbits as the test species. Recycle solvent (RS: 204-427 degrees C) and fuel oil (FO: 204-538 degrees C) were applied to the intact dorsal surface of rabbits, 5 days per week for 4 weeks. Materials were applied as suspensions (2.5 and 10.0 g 100 ml-1) in white oil. White oil alone was administered to concurrent control groups. Both RS and FO elicited gross signs of toxicity including severe dermal irritation, loss of body weight (16-25%) and mortality (4/20 in the high-dose group treated with RS). Systemic effects included liver enlargement as evidenced by histologic findings of diffuse hepatocytomegaly, cytoplasmic degeneration and hepatocellular vacuolation as well as elevated serum cholesterol. There was also evidence of testicular, seminal vesicle and thymic atrophy. More pronounced effects were apparent in the high-dose groups. Testes and epididymides from four of the five FO-treated male rabbits were unremarkable at the microscopic level. The testes, epididymides and seminal vesicles of the fifth animal were atrophic. Three of ten RS treated rabbits showed testicular atrophy associated with hypospermatogenesis in the testes, aspermia in the epididymides and vesiculitis in the seminal vesicles. Four additional animals showed evidence of seminal vesicle atrophy. The liver enlargement was probably due to compensatory metabolism; however, exposure to similar materials at higher levels has resulted in liver toxicity. Thymic and testicular atrophy may have been a secondary response to dermal irritation, stress or body weight loss.
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Ward DP, Trevor AJ, Kalir A, Adams JD, Baillie TA, Castagnoli N. Metabolism of phencyclidine. The role of iminium ion formation in covalent binding to rabbit microsomal protein. Drug Metab Dispos 1982; 10:690-5. [PMID: 6130925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Incubation of phencyclidine (PCP) with rabbit liver microsomes and Na14CN resulted in the metabolically dependent formation of a 14C-labeled cyano adduct of the drug. After isolation by HPLC, this compound was identified as the alpha-aminonitrile [1-(1-phenylcyclohexyl)-2-cyanopiperidine] derivative of PCP by use of chemical-ionization and gas-chromatographic coupled electron-impact mass spectrometry. Synthetic alpha-aminonitrile exhibited identical chemical properties and comigrated in HPLC and GLC with the metabolism derived cyano adduct. Molecular identification of the adduct formed by cyanide trapping provided evidence for the formation of an iminium ion during PCP metabolism. Quantitative estimation by HPLC demonstrated that the alpha-aminonitrile accounted for over 50% of the PCP metabolized in 30 min by hepatic microsomes in vitro. Metabolism-dependent covalent binding of [3H]PCP to rabbit liver microsomal proteins was inhibited by cyanide ion in a concentration-dependent manner with an IC50 value of 57 microM. The concentrations of cyanide ion used in these experiments did not significantly inhibit the metabolism of PCP. These results support our suggestions that iminium ion formation may represent an important intermediary step in the metabolism of PCP and that such a reactive electrophilic species may be capable of covalent interactions with nucleophilic groupings on microsomal macromolecules.
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Bruere AN, Marshall RB, Ward DP. Testicular hypoplasia and XXY sex chromosome complement in two rams: the ovine counterpart of Klinefelter's syndrome in man. J Reprod Fertil 1969; 19:103-8. [PMID: 5815811 DOI: 10.1530/jrf.0.0190103] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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