79 research outputs found

    ANALYSIS OF RESIN AND FATTY ACIDS ENRICHED IN PAPERMAKING PROCESS WATERS

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    The applicability of a special pilot-scale installation (Short Circulation Device) was studied for demonstrating the enrichment of selected resin and fatty acids in process waters when increasing water reuse during the manufacture of paper. The traditional gas chromatography with flame ionization detection (GC-FID), turbidity, and online sample enrichment (solid phase extraction, SPE) for atmospheric pressure chemical ionization-mass spectrometry (APCI-MS) measurements were used for the analysis of the resin and fatty acids. The data from all the measurements with unbleached thermomechanical pulp (TMP) process waters were in a good agreement, and correlation coefficients (R2) > 0.9 were obtained in each case. Rapid information about the levels of wood extractives in papermaking process waters is of great importance, and it offers a suitable way to predict oncoming pitch problems. It was concluded that the routine control of the extractives level in papermaking process waters is possible by all these methods

    MRI-derived cardiac washout is slowed in the left ventricle and associated with left ventricular non-compaction in young patients with cryptogenic ischemic stroke

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    To elucidate underlying disease mechanisms, we compared transition of gadolinium-based contrast agent bolus in cardiac chambers in magnetic resonance imaging between young patents with cryptogenic ischemic stroke and stroke-free controls. We included 30 patients aged 18-50 years with cryptogenic ischemic stroke from the prospective Searching for Explanations for Cryptogenic Stroke in the Young: Revealing the Etiology, Triggers and Outcome (NCT01934725) study and 30 age- and gender-matched stroke-free controls. Dynamic contrast-enhanced T1-weighted first-pass perfusion images were acquired at 1.5 T and analyzed for transit time variables, area under curves, relative blood flow, and maximum and minimum enhancement rates in left atrial appendage, left atrium, and left ventricle. These data were compared with previously published left ventricular non-compaction data of the same study population. Arrival time of contrast agent bolus in superior vena cava was similar in patients and controls (6.7[2.0] vs. 7.1[2.5] cardiac cycles, P = 0.626). Arrival and peak times showed comparable characteristics in patients and controls (P > 0.535). The minimum enhancement rate of the left ventricle was lower in patients than in controls (- 28 +/- 11 vs. - 36 +/- 13 1/(cardiac cycle), P = 0.012). Area under curves, relative blood flow, and other enhancement rates showed no significant differences between patients and controls (P > 0.107). Relative blood flow of cardiac chambers correlated with non-compacted left ventricular volume ratio (P < 0.011). Our results indicate slower washout of contrast agent and blood flow stagnation in the left ventricle of young patients with cryptogenic ischemic stroke. The washout was associated with left ventricular non-compaction, suggesting conditions favoring formation of intraventricular thrombosis.Peer reviewe

    Nanoengineering of Hybrid Lightweight Cellulosic Fibre Foams for better Flame Resistance

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    We studied the flame propagation and combustion properties of a lightweight fibrous foam produced from a layered double hydroxides (LDH) modified thermomechanical pulp fibres. The in situ synthesis of Mg-Al LDH with pulp fibres was engineered to include both micron and nano-sized particles. The method allowed loading the fibres with LDH up to 34% (w/w). Observed pyrolytic effects included 60% reduction in CO2 production rate, and similar reductions in peak heat release rate (PHRR) and in amount of soot during the oxidative pyrolysis. The in situ synthesised LDH particles shielded the fibres from external heat by reducing the rate of oxidation and liberation of volatile gases. Effective charring was observed at the interphase of LDH nanoparticles and organic material.</p

    Left ventricular non-compaction as a potential source for cryptogenic ischemic stroke in the young : A case-control study

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    Background Up to 50% of ischemic strokes in the young after thorough diagnostic work-up remain cryptogenic or associated with low-risk sources of cardioembolism such as patent foramen ovale (PFO). We studied with cardiac magnetic resonance (CMR) imaging, whether left ventricular (LV) non-compaction-a possible source for embolic stroke due to sluggish blood flow in deep intertrabecular recesses-is associated with cryptogenic strokes in the young. Methods Searching for Explanations for Cryptogenic Stroke in the Young: Revealing the Etiology, Triggers, and Outcome (SECRETO; NCT01934725) is an international prospective multicenter case-control study of young adults (aged 18-49 years) presenting with an imaging-positive first-ever ischemic stroke of undetermined etiology. In this pilot substudy, 30 cases and 30 age- and sex-matched stroke-free controls were examined with CMR. Transcranial Doppler (TCD) bubble test was performed to evaluate the presence and magnitude of right-to-left shunt (RLS). Results There were no significant differences in LV volumes, masses or systolic function between cases and controls; none of the participants had non-compaction cardiomyopathy. Semi-automated assessment of LV non-compaction was highly reproducible. Non-compacted LV mass (median 14.0 [interquartile range 12.6-16.0] g/m(2)vs. 12.7 [10.4-16.6] g/m(2), p = 0.045), the ratio of non-compacted to compacted LV mass (mean 25.6 +/- 4.2% vs. 22.8 +/- 6.0%, p = 0.015) and the percentage of non-compacted LV volume (mean 17.6 +/- 2.9% vs. 15.7 +/- 3.8%, p = 0.004) were higher in cases compared to controls. In a multivariate conditional logistic regression model including non-compacted LV volume, RLS and body mass index, the percentage of non-compacted LV volume (odds ratio [OR] 1.55, 95% confidence interval [CI] 1.10-2.18, p = 0.011) and the presence of RLS (OR 11.94, 95% CI 1.14-124.94, p = 0.038) were independently associated with cryptogenic ischemic stroke. Conclusions LV non-compaction is associated with a heightened risk of cryptogenic ischemic stroke in young adults, independent of concomitant RLS and in the absence of cardiomyopathy.Peer reviewe

    Puusta pidemmälle:Määrästä arvoon

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    Right atrium and cryptogenic ischaemic stroke in the young : A case-control study

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    Publisher Copyright: © 2021 BMJ Publishing Group. All rights reserved.Background Recent studies suggest left atrial (LA) dysfunction in cryptogenic stroke. We studied the dynamics of right atrium (RA) and right atrial appendage (RAA) in young adults with cryptogenic stroke. We hypothesised that bi-atrial dysfunction and blood stagnation might contribute to thrombosis formation in patients with patent foramen ovale (PFO), as deep venous thrombosis is detected only in the minority of patients. Methods Thirty patients (aged 18-49) with a first-ever cryptogenic stroke and 30 age-matched and sex-matched stroke-free controls underwent cardiac magnetic resonance (CMR) imaging. An approach to estimate the RAA volume was developed, using crista terminalis and pectinate muscles as anatomical landmarks. Atrial expansion indices were calculated as (maximal volume - minimal volume) ×100%/minimal volume. Total pulmonary to systemic blood flow ratio (Qp/Qs) was based on phase contrast CMR. Right-to-left shunt (RLS) was evaluated with transoesophageal echocardiography in 29 patients and transcranial Doppler in 30 controls, moderate-to-severe RLS considered as clinically significant. Results We found that RA and RAA volumes were similar between patients and controls. Also, RA expansion index was similar, but RAA (95.6%±21.6% vs 108.7%±25.8%, p=0.026) and LA (126.2%±28% vs 144.9%±36.3%, p=0.023) expansion indices were lower in patients compared with controls. Seven (24%) of 29 patients had an RLS compared with 1 (3%) of 30 controls (p=0.012). Among 59 study subjects, RLS was associated with lower RA (81.9%±15.9% vs 98.5%±29.5%, p=0.030), RAA (84.7%±18% vs 105.6%±24.1%, p=0.022), LA (109.8%±18.6% vs 140.1%±33.7%, p=0.017) and LAA (median 102.9% (IQR 65.6%-121.7%) vs 229.1% (151.8%-337.5%], p=0.002) expansion indices and lower Qp/Qs ratio (0.91±0.06 vs 0.98±0.07, p=0.027). Conclusions This study suggests bi-atrial dysfunction in young adults with cryptogenic stroke, associated with moderate-to-severe RLS. Dysfunction of the atria and atrial appendages may be an additional mechanism for PFO-related stroke. Trial registration number NCT01934725.Peer reviewe

    Puusta pidemmälle:Määrästä arvoon

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    Kotimaan vihreästä kullasta valmistetuista tuotteista saadaan monia tuotteita kiertotalouden avulla. Olemme kehittäneet uutta, puumateriaaleihin pohjautuvaa liiketoimintaa yhdessä yritysten, tutkimuslaitosten ja koulutusorganisaatioiden kanssa. Olemme hypänneet puusta pidemmälle – määrästä arvoon.Hankkeessa olemme luoneet metsäalalle uusia työkaluja ja toimintamalleja, joiden avulla puutuotteiden laatu korvaa määrän.Kiertotaloudessa puusta valmistetaan mahdollisimman pitkäikäisiä tuotteita, joita voidaan hyödyntää moneen kertaan ja siten luoda samalle puumateriaalille taloudellista arvoa yhä uudelleen ja uudelleen. Nykyään jätteeksi päätyvä puuaines hyödynnetäänkin jatkossa kestävästi uusien tuotteiden valmistamiseen. Puutuotteisiin voidaan lisätä myös aineetonta arvoa digitaalisten teknologioiden ja palveluiden avulla.Hankkeessa testattiin nopean kokeilun ja innovoinnin työpajamallia, jonka avulla metsäalan yritykset, muotoilijat ja markkinoijat kehittivät yhdessä uusia liikeideoita puutuotteille. Hankkeen aikana tutkittiin myös puutuotteiden kiertotalouden edistämismahdollisuuksia, toteutettiin puutuotteiden elinkaarilaskuri, tutkittiin digitalisaation mahdollisuuksia, sekä suunniteltiin ja testattiin kiertotalouden markkinointikonseptia kaikkien yritysten käyttöön.Lisäksi hankkeessa mukana olevat yritykset kehittivät yhdessä teknologiaa uudella tavalla hyödyntäviä puupohjaisia tuotteitaan. Tavoitteena on ollut luoda uutta, kiertotalouden mukaista liiketoimintaa Suomeen ja edistää samalla Suomen kansainvälistä kilpailukykyä.Hankkeen ajankohta: 4.5.2018-15.10.201

    Revisiting left atrial volumetry by magnetic resonance imaging : the role of atrial shape and 3D angle between left ventricular and left atrial axis

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    Background Accurate measurement of left atrial (LA) volumes is needed in cardiac diagnostics and the follow up of heart and valvular diseases. Geometrical assumptions with 2D methods for LA volume estimation contribute to volume misestimation. In this study, we test agreement of 3D and 2D methods of LA volume detection and explore contribution of 3D LA axis orientation and LA shape in introducing error in 2D methods by cardiovascular magnetic resonance imaging. Methods 30 patients with prior first-ever ischemic stroke and no known heart disease, and 30 healthy controls were enrolled (age 18-49) in a substudy of a prospective case-control study. All study subjects underwent cardiac magnetic resonance imaging and were pooled for this methodological study. LA volumes were calculated by biplane area-length method from both conventional long axis (LAV(AL-LV)) and LA long axis-oriented images (LAV(AL-LA)) and were compared to 3D segmented LA volume (LAV(SAX)) to assess accuracy of volume detection. 3D orientation of LA long axis to left ventricular (LV) long axis and to four-chamber plane were determined, and LA 3D sphericity indices were calculated to assess sources of error in LA volume calculation. Shapiro-Wilk test, Bland-Altman analysis, intraclass and Pearson correlation, and Spearman's rho were used for statistical analysis. Results Biases were - 9.9 mL (- 12.5 to - 7.2) for LAV(AL-LV) and 13.4 (10.0-16.9) for LAV(AL-LA) [mean difference to LAV(SAX) (95% confidence interval)]. End-diastolic LA long axis 3D deviation angle to LV long axis was 28.3 +/- 6.2 degrees [mean +/- SD] and LA long axis 3D rotation angle to four-chamber plane 20.5 +/- 18.0 degrees. 3D orientation of LA axis or 3D sphericity were not correlated to error in LA volume calculation. Conclusions Calculated LA volume accuracy did not improve by using LA long axis-oriented images for volume calculation in comparison to conventional method. We present novel data on LA axis orientation and a novel metric of LA sphericity and conclude that these measures cannot be utilized to assess error in LA volume calculation.Peer reviewe
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