796 research outputs found

    Electrical impedance spectroscopy in relation to seed viability and moisture content in snap bean (Phaseolus vulgaris L.)

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    A method, electrical impedance spectroscopy (EIS), is introduced to study seed viability non-destructively. Snap bean (Phaseolus vulgaris L.) seeds were studied by EIS to determine the most sensitive EIS parameter(s) and the optimal range of moisture content (MC) for separation of viable and non-viable seeds. Hydrated seeds exhibited two impedance arcs in the complex plane at the frequency range from 60 Hz to 8 MHz, and impedance spectra of viable and non-viable seeds differed. The hydrated seeds were best-modelled by an equivalent electrical circuit with two distributed circuit elements in series with a resistor (Voigt model). Moisture content and seed viability had strong effects on the EIS parameters. The most sensitive EIS parameters for detecting the differences between viable and non-viable seeds were the capacitance log(C2), the resistance R2, the resistance ratio R2/R1 and the apex ratio, which all represent specific features of the impedance spectrum. The highest differentiation in the EIS parameters between the viable and non-viable seeds occurred in partially imbibed seeds between MC of 40 and 45% (fresh weight basis

    Microwave-enhanced aqueous biphasic dehydration of carbohydrates to 5-hydroxymethylfurfural

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    We describe herein an efficient microwave-assisted aqueous biphasic dehydration of carbohydrates to 5-hydroxymethylfurfural (HMF). The effects of several alkali metal salts in aqueous phase, organic solvents as an extractive phase and Lewis acids are evaluated on the reaction. Specifically, starting from fructose, the use of bromide salts in aqueous phase and the common organic solvent MeCN or lignocellulose-derived gamma-valerolactone (GVL) as organic extractors are highly beneficial, leading to excellent HMF yields of up to 91% with HCl as a Bronsted acid catalyst. In conjunction with an isomerization catalyst, the method was applicable to glucose as well as various disaccharides and cellulose, affording HMF in notably good yields, particularly with GVL as an extractor and reusable Amberlyst-38(wet) as an acid catalyst. The exceptionally high HMF yields obtained in aqueous solutions is attributed to the combined effect of the biphasic reaction system and the application of microwaves, which ensures short reaction times and minimized by-product formation thereof.Peer reviewe

    Transition metal triflate catalyzed conversion of alcohols, ethers and esters to olefins

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    Herein, we report an efficient transition metal triflate catalyzed approach to convert biomass-based compounds, such as monoterpene alcohols, sugar alcohols, octyl acetate and tea tree oil, to their corresponding olefins in high yields. The reaction proceeds through C-O bond cleavage under solvent-free conditions, where the catalytic activity is determined by the oxophilicity and the Lewis acidity of the metal catalyst. In addition, we demonstrate how the oxygen containing functionality affects the formation of the olefins. Furthermore, the robustness of the used metal triflate catalysts, Fe(OTf)(3) and Hf(OTf)(4), is highlighted by their ability to convert an over 2400-fold excess of 2-octanol to octenes in high isolated yields.Peer reviewe

    Replacing C6F5 groups with Cl and H atoms in frustrated Lewis pairs : H-2 additions and catalytic hydrogenations

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    2-(Dialkylamino) phenylboranes containing the BXZ group, where X, Z = C6F5, Cl, and H, were prepared in a few synthetic steps and demonstrated the cleavage of H-2 under mild conditions. Depending on the nature of the dialkylamino group, X, and Z, the stability of the produced zwitterionic H-2 adducts varies from isolated solids indefinitely stable in an inert atmosphere to those quickly equilibrating with the initial aminoborane and H-2. Using a combined experimental/computational approach on a series of isostructural aminoboranes (dialkylamino = 2,2,6,6-tetramethylpiperid-1-yl), it was demonstrated that the electro-negativity and the steric effect of the substituents generally follow the trend C6F5 similar to Cl >> H. This observation is useful for designing new FLPs for practical applications. As an example, we demonstrated the hydrogenation of alkynes to cis-alkenes under mild conditions that was catalyzed by a chloro-analogue of the C6F5-substituted aminoborane developed previously. The presence of a BHCl group in the amino-chloroboranes or in their H-2 adducts features facile redistribution of the H and Cl atoms and the formation of polychloro and polyhydrido species.Peer reviewe

    Reliability and Validity of The Finnish Version of The Boston Carpal Tunnel Questionnaire among Surgically Treated Carpal Tunnel Syndrome Patients

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    Background and Aims: The Boston Carpal Tunnel Questionnaire is the most commonly used outcome measure in the assessment of carpal tunnel syndrome. The purpose of this study was to translate the original Boston Carpal Tunnel Questionnaire into Finnish and validate its psychometric properties. Materials and Methods: We translated and culturally adapted the Boston Carpal Tunnel Questionnaire into Finnish. Subsequently, 193 patients completed the Finnish version of the Boston Carpal Tunnel Questionnaire, 6-Item CTS Symptoms Scale, and EuroQol 5 Dimensions 12 months after carpal tunnel release. The Boston Carpal Tunnel Questionnaire was re-administered after a 2-week interval. We calculated construct validity, internal consistency, test-retest reliability, and coefficient of repeatability. We also examined floor and ceiling effects. Results: The cross-cultural adaptation required only minor modifications to the questions. Both subscales of the Boston Carpal Tunnel Questionnaire (Symptom Severity Scale and Functional Status Scale) correlated significantly with the CTS-6 and EuroQol 5 Dimensions, indicating good construct validity. The Cronbach's alpha was 0.93 for both the Symptom Severity Scale and Functional Status Scale, indicating high internal consistency. Test-retest reliability was excellent, with an intraclass correlation coefficient greater than 0.8 for both scales. The coefficient of repeatability was 0.80 for the Symptom Severity Scale and 0.68 for the Functional Status Scale. We observed a floor effect in the Functional Status Scale in 28% of participants. Conclusion: Our study shows that the present Finnish version of the Boston Carpal Tunnel Questionnaire is reliable and valid for the evaluation of symptom severity and functional status among surgically treated carpal tunnel syndrome patients. However, owing to the floor effect, the Functional Status Score may have limited ability to detect differences in patients with good post-operative outcomes.Peer reviewe

    The stability of green nanoparticles in increased pH and salinity for applications in oil spill-treatment

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    AbstractThe melting of the permanent ice cover in the arctic region due to the climate change is increasing industrial activity in the region and also consequently there is the enhanced risk for oil-spills. Therefore, there is a need for the development of green chemicals for oil-spill treatment in the arctic region. Carboxymethylated chitosan nanoparticles were cross-linked with Mg, Ca or Sr and the stability of nanoparticles in increased pH and salinity was studied. The carboxymethylation of chitosan was investigated with FTIR and the nanoparticles were studied with dynamic light scattering and SEM. The nanoparticles cross-linked with Ca ions were found to be most stable in increased salinity and pH. The interaction of Ca cross-linked nanoparticles with dodecane in water was also demonstrated. The nanoparticles showed promising potential for applications in oil-spill treatment

    Validation of the Finnish version of the BODY-Q patient-reported outcome instrument among patients who underwent abdominoplasty

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    Background: Massive weight loss can notably affect patients' health-related quality of life (HRQoL) and body image. Yet, no body contouring specific instruments to assess HRQoL and body image after massive weight loss have been validated in Finnish. The BODY-Q includes 26 independently functioning scales and a single checklist that measure appearance, HRQoL, and experience of care. The aim of the present study was to translate and validate a Finnish version of the BODY-Q among patients who underwent abdominoplasty. Methods: The BODY-Q was translated into Finnish using recommended guidelines. Eighty-two patients who underwent abdominoplasty due to massive weight loss were identified from hospital records using procedure codes. A postal survey including the BODY-Q, the 15D, and general health and pain instruments was used. Criterion validity, Cronbach's alpha, and floor and ceiling effects were analyzed. Results: The BODY-Q translated well into Finnish. Fifty-three patients returned the questionnaires (response rate 65%) and were included. All but the Scars subscale correlated significantly with the 15D mean score, thus indicating strong criterion validity against a generic HRQoL tool. The Excess Skin and the Physical Function scales reached the ceiling effect (>15% of maximum points) in our postoperative sample. No floor effects were observed. Internal consistency of the BODY-Q scales was high (Cronbach's alpha range, 0.81-0.95). Conclusions: The Finnish version of the BODY-Q instrument is equivalent in terms of content, accuracy, and comprehensiveness to the original English version. The findings of the present study indicate that the BODY-Q has psychometric properties suitable for assessing outcomes and treatment effectiveness of abdominoplasty. (C) 2019 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Assessment of the structural validity of three foot and ankle specific patient-reported outcome measures

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    Background: The structural validity of the Lower extremity functional scale (LEFS), the Visual analogue scale foot and ankle (VAS-FA), and the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) has not been compared earlier in patients after foot and ankle surgery. Methods: Altogether 165 previously operated patients completed the foot and ankle specific instruments, the 15D health-related quality of life (HRQoL) instrument, and general health (VAS). Results: The LEFS, the VAS-FA and the WOMAC had slight differences in their measurement properties. The VAS-FA had the best targeting and coverage. All three foot and ankle measures accounted for mobility and usual activities when compared to the different aspects of generic HRQoL. Conclusions: The LEFS, the VAS-FA and the WOMAC have relatively similar psychometric properties among foot and ankle patients, yet the VAS-FA provides the best targeting and coverage. (C) 2019 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Immune activation in the small intestine in patients with rheumatoid arthritis

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    Objectives: To determine whether inflammation in the gut associated immune system is activated in rheumatoid arthritis ( RA). The expression of chemokine receptor- (CCR4, CCR5) and cytokine- ( interleukin (IL) 2, IL10, interferon gamma (IFNgamma), tumour necrosis factor alpha (TNFalpha), and transforming growth factor beta (TGFbeta)) specific mRNA in intestinal biopsy samples from patients with RA was examined. Methods: Duodenal biopsy samples from 13 patients with RA and 15 control subjects were studied. The mRNA expression of CCR4, CCR5, IL2, IL10, IFNgamma, TNFalpha, and TGFb in intestinal biopsy samples was demonstrated by real time quantitative reverse transcriptase-polymerase chain reaction. Results: The mRNA expression of CCR4, CCR5, and IL10 in intestinal biopsy samples was increased in patients with RA in comparison with control subjects ( p = 0.001, p = 0.046, p = 0.019). No difference in the expression levels of IL2, IFNgamma, TNFalpha, or TGFbeta was seen between patients with RA and controls. Conclusions: The increased intestinal mRNA expression of IL10, CCR5, and CCR4 suggests that gut associated immune cells are activated in patients with RA.Peer reviewe
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