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Savale N, Tarasova E, Krasnou I, Kudrjašova M, Rjabovs V, Reile I, Heinmaa I, Krumme A. Optimization and degradation studies of cellulose transesterification to palmitate esters in superbase ionic liquid. Carbohydr Res 2024; 537:109047. [PMID: 38359696 DOI: 10.1016/j.carres.2024.109047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/26/2024] [Accepted: 01/29/2024] [Indexed: 02/17/2024]
Abstract
Cellulose palmitates (CPs) were synthesized with varying degrees of substitution (DS) via a catalyst-free, homogeneous transesterification of cellulose in a novel superbase ionic liquid (SB-IL) system, specifically 5-methyl-1,5,7-triaza-bicyclo[4.3.0]non-6-enium acetate [mTBNH][OAc], combined with dimethyl sulfoxide (DMSO) as a co-solvent, using vinyl palmitate as the acylating agent. We examined the influence of reaction temperature, reaction time, and the molar ratio of vinyl palmitate to anhydroglucose unit (AGU) on the DS, which ranged from 0.5 to 2.3 under the given conditions. Notably, the reaction order of the three hydroxy groups was C6-OH > C2-OH > C3-OH. To elucidate the chemical structure of CPs and confirm the transesterification process, various spectroscopic techniques including 1H nuclear magnetic resonance (NMR), 13C NMR, heteronuclear single quantum correlation (HSQC), and solid-state NMR were employed. Higher reaction temperatures and extended reaction times led to a decrease in the DS of CPs, potentially due to the degradation of some of the involved chemicals during the transesterification process. We also investigated the stability of the pure ionic liquid (IL) and the IL + DMSO solvent system at elevated temperatures by heating them at 100 °C for 5 h, confirming their chemical integrity through 1H NMR analysis. Additionally, we assessed the compatibility between the solvent system and cellulose by subjecting a mixture of cellulose and the solvent system to 100 °C for 5 h. To compare the structures of untreated cellulose and regenerated cellulose, Fourier transform infrared (FT-IR) spectroscopy was employed. Furthermore, we determined the molar mass of both untreated cellulose and regenerated cellulose, as well as CPs synthesized at higher reaction temperatures and longer durations, using intrinsic viscosity measurements. Lastly, we examined the solubility properties of CPs.
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Affiliation(s)
- N Savale
- School of Engineering, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, 19086, Tallinn, Estonia.
| | - E Tarasova
- School of Engineering, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, 19086, Tallinn, Estonia
| | - I Krasnou
- School of Engineering, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, 19086, Tallinn, Estonia
| | - M Kudrjašova
- School of Science, Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia
| | - V Rjabovs
- National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618, Tallinn, Estonia
| | - I Reile
- National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618, Tallinn, Estonia
| | - I Heinmaa
- National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618, Tallinn, Estonia
| | - A Krumme
- School of Engineering, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, 19086, Tallinn, Estonia
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Mandre N, Plamus T, Linder A, Krumme A, Rohumaa A. Impact of laser fading on physico-mechanical properties and fibre morphology of multicomponent denim fabrics. PEAS 2023. [DOI: 10.3176/proc.2023.2.05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/01/2023]
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Abbas MM, Ahmad T, Ahranjani RR, Antonov M, Farid MM, Goliandin D, Hussain A, Kamboj N, Krasnou I, Krumme A, Kumar R, Podgursky V, Viljus M. Tribological and circular economy aspects of polypropylene/cotton fibre hybrid composite. PEAS 2022. [DOI: 10.3176/proc.2022.2.03] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Baumgartner S, Viirsalu M, Krumme A, Mendez J. Properties of chitin extracted from Estonian mushrooms. Proc Estonian Acad Sci 2019. [DOI: 10.3176/proc.2019.3.09] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Viirsalu M, Savest N, Plamus T, Vassiljeva V, Krumme A. Novel method for producing electrospun composite nanofibre yarns. Proc Estonian Acad Sci 2018. [DOI: 10.3176/proc.2018.2.09] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Dong YH, Choudhry NK, Krumme A, Lee MP, Wu LC, Lai MS, Gagne JJ. Impact of hospitalization on medication adherence estimation in claims data. J Clin Pharm Ther 2017; 42:318-328. [PMID: 28370404 DOI: 10.1111/jcpt.12517] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [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: 12/23/2016] [Accepted: 02/15/2017] [Indexed: 11/30/2022]
Abstract
WHAT IS KNOWN AND OBJECTIVE Pharmacy claims are commonly used to assess medication adherence. It is unclear how different approaches to handling hospitalizations compare to the gold standard of using outpatient and inpatient drug data. This study aimed to compare the impact of different approaches to handling hospitalizations on medication adherence estimation in administrative claims data. METHODS We identified β-blocker initiators after myocardial infarction (MI) and statin initiators regardless of hospitalization histories in the population-based, Taiwan database, which includes outpatient and inpatient drug claims data. Adherence to β-blockers or to statins during a 365-day follow-up period was estimated in outpatient pharmacy claims using the proportion of days covered (PDC) in three ways: ignoring hospitalizations (PDC1); subtracting hospitalized days from the denominator (PDC2); and assuming drug use on all hospitalized days (PDC3). We compared these to an approach that incorporated inpatient drug use (PDC4). We also used a hypothetical example to examine variations across approaches in several scenarios, such as increasing hospitalized days. RESULTS AND DISCUSSION Mean 365-day PDC was 74% among 1729 post-MI β-blocker initiators (range: 73.1%-74.9%) and 44% among 69 435 statins initiators (range: 43.5%-44.0%), which varied little across approaches. Differences across approaches increased with increasing number of hospitalized days. For patients hospitalized for >28 days, mean difference across approaches was >15%. PDC3 consistently yielded the highest value and PDC1 the lowest. WHAT IS NEW AND CONCLUSIONS On average, different approaches to handling hospitalizations lead to similar adherence estimates to the gold standard of incorporating inpatient drug use. When patients have many hospitalization days during follow-up, the choice of approach should be tailored to the specific setting.
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Affiliation(s)
- Y-H Dong
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.,Faculty of Pharmacy, School of Pharmaceutical Science, National Yang-Ming University, Taipei, Taiwan.,Center of Comparative Effectiveness Research, National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan
| | - N K Choudhry
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - A Krumme
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - M P Lee
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - L-C Wu
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - M-S Lai
- Center of Comparative Effectiveness Research, National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan.,Graduate Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - J J Gagne
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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Tikk T, Paara T, Eltermann M, Krumme A, Jaaniso R, Kiisk V, Lange S. TiO2:Sm3+ based luminescent oxygen sensitive probes in LDPE packaging material. Proc Estonian Acad Sci 2017. [DOI: 10.3176/proc.2017.4.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Krasnou I, Tarasova E, Märtson T, Krumme A. Thermoplastic Cellulose Stearate and Cellulose Laurate: Melt Rheology, Processing and Application Potential. INT POLYM PROC 2015. [DOI: 10.3139/217.2980] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
In this work thermoplastic materials from cellulose fatty acid esters were manufactured, their properties described and application and processing perspectives evaluated. Rheological properties of some cellulose esters in melt were studied under conditions similar to those usually used in industrial polymer processing. Thermoplastic properties of cellulose esters were compared with properties of low density polyethylene under the same conditions. It was discovered that long chain fatty acid cellulose esters could be processed in the same way as commodity polymers, but these materials need further improvement for being industrially applied as thermoplastic polymers.
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Affiliation(s)
- I. Krasnou
- Department of Polymer Materials , Tallinn University of Technology, Tallinn , Estonia
| | - E. Tarasova
- Department of Polymer Materials , Tallinn University of Technology, Tallinn , Estonia
| | - T. Märtson
- Department of Polymer Materials , Tallinn University of Technology, Tallinn , Estonia
| | - A. Krumme
- Department of Polymer Materials , Tallinn University of Technology, Tallinn , Estonia
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Kallakas H, Poltimäe T, Süld TM, Kers J, Krumme A. The influence of accelerated weathering on the mechanical and physical properties of wood-plastic composites. Proc Estonian Acad Sci 2015. [DOI: 10.3176/proc.2015.1s.05] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Šumigin D, Tarasova E, Krumme A, Viikna A. Influence of cellulose content on thermal properties of poly(lactic) acid/cellulose and low-density polyethylene/cellulose composites. Proc Estonian Acad Sci 2012. [DOI: 10.3176/proc.2012.3.14] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Aruniit A, Kers J, Majak J, Krumme A, Tall K. Influence of hollow glass microspheres on the mechanical and physical properties and cost of particle reinforced polymer composites. Proc Estonian Acad Sci 2012. [DOI: 10.3176/proc.2012.3.03] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Märtson T, Krumme A, Gavrilkina V, Viikna A. The effect of modality on linear low-density polyethylene crystallization behaviour at high and very high supercoolings. Proc Estonian Acad Sci 2009. [DOI: 10.3176/proc.2009.1.09] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Poltimäe T, Tarasova E, Krumme A, Lehtinen A, Viikna A. Behaviour of the very-low-temperature crystallization peak of linear low-density polyethylene. Proc Estonian Acad Sci 2009. [DOI: 10.3176/proc.2009.1.10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Kelman A, Lui L, Yao W, Krumme A, Nevitt M, Lane NE. Association of higher levels of serum cartilage oligomeric matrix protein and N-telopeptide crosslinks with the development of radiographic hip osteoarthritis in elderly women. ACTA ACUST UNITED AC 2005; 54:236-43. [PMID: 16385523 DOI: 10.1002/art.21527] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To examine the association of baseline concentrations of serum cartilage oligomeric matrix protein (COMP) and serum N-telopeptide crosslinks (NTX) with the development and progression of radiographic hip osteoarthritis (RHOA) in elderly women. METHODS Pelvic radiographs were obtained a mean of 8.3 years apart from white women > or =65 years of age enrolled in the Study of Osteoporotic Fractures. Random sampling from a cohort of 5,928 subjects was performed, with subjects ( approximately 200 per group) assigned to nested case-control studies, one focusing on RHOA incidence and the other on RHOA progression. Baseline serum levels of COMP and NTX were measured by enzyme-linked immunosorbent assay in duplicate. Odds ratios (ORs) and 95% confidence intervals (95% CIs), indicating the likelihood of baseline serum COMP and NTX levels to be predictive of the development or progression of RHOA, were calculated using logistic regression analysis, with adjustment for potential covariates. RESULTS At baseline, incident cases of RHOA were associated with higher serum levels of COMP and NTX (P < 0.05 for each) compared with the no RHOA control group. Higher baseline serum COMP and NTX levels were associated with an increased risk of incident RHOA compared with the no RHOA group, with an adjusted OR of 1.31 per SD increase in COMP (95% CI 1.02-1.68) and adjusted OR of 1.38 per SD increase in NTX (95% CI 1.07-1.79). In this community-based cohort, progression of RHOA was modest. However, there was a trend toward increased risk of RHOA progression with higher baseline COMP and NTX levels. CONCLUSION These data suggest that serum levels of COMP and NTX are modest risk markers for the development of RHOA in a community-based cohort of elderly white women.
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Affiliation(s)
- A Kelman
- Stanford University Medical Center, Stanford, California, USA
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