884 resultados para polishing filtration


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Työssä tutkittiin softkalanteroinnin vaikutus heat set web offset-luettelopaperin laatu- ja painatusominaisuuksiin. Tavoitteena oli löytää luettelopaperin laatuvaatimukset täyttävä ajotapa softkalanterille. Työn kirjallisessa osassa käsitellään softkalanteroinnin teoriaa, softkalanteroinnin vaikutusta sanomalehti-paperin laatuun sekä soft- ja konekalanteroinnin eroja. Lisäksi käsitellään painatusta; densiteettiä ja sen vaikutusta paperin läpipainatukseen. Työn kokeellisessa osassa tutkittiin softkalanterin lämpötilan ja viivapaineen vaikutus luettelopaperin laatuun. Paras laatu sileyden, kiillon sekä painojäljen kannalta saavutetaan käyttämällä korkeaa kalanterin lämpötilaa ja viivapainetta. Massaseoksessa tulisi olla niin paljon hioketta kuin paperin lujuusominaisuudet sallivat. Hioke antaa paperille tasaisen painojäljen. Täyteainetta tulisi käyttää, koska se nostaa opasiteettia ja pienentää läpipainatusta sekä helpottaa kalanteroitumista. Helpommin kalanteroituva paperi pienentää paperin huokostilavuutta, jolla on edullinen vaikutus paperin läpipainatukseen. Luettelopaperin kalanteroiminen yhdellä nipillä on mahdollista, mutta ei suotavaa. Tällöin paperista tulee toispuoleista karheuden suhteen.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Teknologian kehitys ja prosessien tiukempi valvonta ovat alentaneet selluteollisuuden häviöitä tehden prosesseista suljetumpia. Valitettavasti nämä edistysaskeleet teknologiassa ovat lisänneet prosessiin kuulumattomien yhdisteiden määrää kemikaalien talteenottokierrossa. Näistä kemikaaleista haitallisimpia ovat kloridi- ja kaliumyhdisteet, jotka tulevat prosessiin raaka-aineiden ja prosessikemikaalien mukana. Kloridi ja kalium muodostavat emäksisissä liuoksissa epäorgaanisia liukoisia yhdisteitä, jotka rikastuvat lipeäkiertoon. Soodakattilassa kloridien läsnäolo alentaa tuhkan sulamislämpötilaa sekä tarttumispistettä, lisää korroosiota ja saostumien muodostumista kattilan pinnalle. Nämä seuraukset voivat vähentää vuosituotantoa ja nostaa korjauskustannuksia. Kaliumin ja kloridin rikastumista talteenottokiertoon voidaan estää poistamalla ne prosessista. Prosessiin kuulumattomat yhdisteet tulisi poistaa talteenottoprosessista ja säilyttää samalla korkea kemikaalien talteenottoprosentti. Koska kaliumin ja kloridin rikastumiskertoimet soodakattilan tuhkassa ovat korkeita, on tuhkan käsittely tehokasta. Kloridin ja kaliumin poistoon on kehitetty menetelmiä, joilla voidaan vähentää hyödyllisten kemikaalien häviöitä. Näitä menetelmiä ovat uutto, ioninvaihto, elektrodialyysi, jäähdytyskiteytys ja haihdutuskiteytys. Menetelmissä tuhka jaetaan kloridi- ja kaliumpitoiseen osaan ja natriumsulfaattipitoiseen osaan. Kloridi ja kalium poistetaan prosessista ja loput palautetaan lipeäkiertoon. Kloridin ja kaliumin poistoa tuhkasta tutkittiin uuttamalla tuhkaa vedellä. Parhaissa käyttöolosuhteissa natriumsulfaatin liukoisuus veteen on huomattavasti alhaisempi kuin kaliumkloridin liukoisuus veteen. Optimaalinen uuttolämpötila ja tuhka-vesisuhde määritettiin siten, että kloridi- ja kaliumpitoisuudet suodoksessa olivat mahdollisimman korkeat sekä natriumin ja muiden anioneiden pitoisuudet suodoksessa mahdollisimman alhaiset. Saatuja tuloksia käytettiin jatkuvatoimisen uuttoprosessin suunnittelussa.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Kosteusmittauksesta on tullut tärkeä osa teollisuuden kunnossapitoa ja huoltotoimenpiteitä. Yritykset valvovat entistä tarkemmin prosesseitaan erilaisten mittalaitteiden avulla. Diplomityön tavoitteena oli selvittää kosteuslähetin HMP228:n markkinoita. Diplomityössä kartoitettiin suuria ja kansainvälisillä markkinoilla toimivia suodatin- ja separaattorivalmistajia, joiden toimintaan kosteusmittaus oleellisesti liittyy. Työssä keskityttiin noin kymmeneen suurimpaan suodatin- sekä eparaattori valmistajaan, jotka eivät itse valmista kosteusmittalaitteita. Näistä yrityksistä valittiin analysoinnin jälkeen potentiaalisimmat vaihtoehdot. Työssä tarkasteltiin myös muita kosteusmittauksen sovellusalueille tuotteita valmistavia yrityksiä. Nämä olivat kuitenkin toiminnaltaan huomattavasti suuria suodatin- ja separaattorivalmistajia pienempiä. Diplomityön loppuosassa tarkasteltiin asiakastarpeita ja QFD- analyysiä. Sopivia yrityksiä löytyi suodatin- sekä separaattorivalmistajien joukosta yhteensä kuusi kappaletta. Valittujen yritysten avulla voidaan tehostaa HMP228:n myyntiä, sillä perusteellinen tieto sovelluskohteista sekä loppuasiakkaiden tarpeista helpottaa markkinointia. Myyntivolyymin kasvattaminen vaatii myös oman markkinoinnin ja myynnin tehostamista. Markkinointitoimenpiteinä erilaiset lehtiartikkelit voisivat lisätä tuotteen tunnettavuutta. Myynnin sekä markkinoinnin lisäksi tarvitaan myös työtä kentällä, yrityskäyntejä ja uusien asiakassuhteiden luomista

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Molecular evidence suggests that levels of vitamin D are associated with kidney function loss. Still, population-based studies are limited and few have considered the potential confounding effect of baseline kidney function. This study evaluated the association of serum 25-hydroxyvitamin D with change in eGFR, rapid eGFR decline, and incidence of CKD and albuminuria. Baseline (2003-2006) and 5.5-year follow-up data from a Swiss adult general population were used to evaluate the association of serum 25-hydroxyvitamin D with change in eGFR, rapid eGFR decline (annual loss >3 ml/min per 1.73 m(2)), and incidence of CKD and albuminuria. Serum 25-hydroxyvitamin D was measured at baseline using liquid chromatography-tandem mass spectrometry. eGFR and albuminuria were collected at baseline and follow-up. Multivariate linear and logistic regression models were used considering potential confounding factors. Among the 4280 people included in the analysis, the mean±SD annual eGFR change was -0.57±1.78 ml/min per 1.73 m(2), and 287 (6.7%) participants presented rapid eGFR decline. Before adjustment for baseline eGFR, baseline 25-hydroxyvitamin D level was associated with both mean annual eGFR change and risk of rapid eGFR decline, independently of baseline albuminuria. Once adjusted for baseline eGFR, associations were no longer significant. For every 10 ng/ml higher baseline 25-hydroxyvitamin D, the adjusted mean annual eGFR change was -0.005 ml/min per 1.73 m(2) (95% confidence interval, -0.063 to 0.053; P=0.87) and the risk of rapid eGFR decline was null (odds ratio, 0.93; 95% confidence interval, 0.79 to 1.08; P=0.33). Baseline 25-hydroxyvitamin D level was not associated with incidence of CKD or albuminuria. The association of 25-hydroxyvitamin D with eGFR decline is confounded by baseline eGFR. Sufficient 25-hydroxyvitamin D levels do not seem to protect from eGFR decline independently from baseline eGFR.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: Primary hyperoxaluria type 3 (PH3) is characterized by mutations in the 4-hydroxy-2-oxoglutarate aldolase (HOGA1) gene. PH3 patients are believed to present with a less severe phenotype than those with PH1 and PH2, but the clinical characteristics of PH3 patients have yet to be defined in sufficient detail. The aim of this study was to report our experience with PH3. METHODS: Genetic analysis of HOGA1 was performed in patients with a high clinical suspicion of PH after the presence of mutations in the alanine-glyoxylate aminotransferase gene had been ruled out. Clinical, biochemical and genetic data of the seven patients identified with HOGA1 mutations were subsequently retrospectively reviewed. RESULTS: Among the seven patients identified with HOGA1 mutations the median onset of clinical symptoms was 1.8 (range 0.4-9.8) years. Five patients initially presented with urolithiasis, and two other patients presented with urinary tract infection. All patients experienced persistent hyperoxaluria. Seven mutations were found in HOGA1, including two previously unreported ones, c.834 + 1G > T and c.3G > A. At last follow-up, two patients had impaired renal function based on estimated glomerular filtration rates (GFRs) of 77 and 83 mL/min per 1.73 m(2), respectively. CONCLUSIONS: We found that the GFR was significantly impaired in two of our seven patients with PH3 diagnosed during childhood. This finding is in contrast to the early-impaired renal function in PH1 and PH2 and appears to refute to preliminary reassuring data on renal function in PH3.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In order to investigate a possible association between soybean malate synthase (MS; L-malate glyoxylate-lyase, CoA-acetylating, EC 4.1.3.2) and glyoxysomal malate dehydrogenase (gMDH; (S)-malate: NAD(+) oxidoreductase, EC 1.1.1.37), two consecutive enzymes in the glyoxylate cycle, their elution profiles were analyzed on Superdex 200 HR fast protein liquid chromatography columns equilibrated in low- and high-ionic-strength buffers. Starting with soluble proteins extracted from the cotyledons of 5-d-old soybean seedlings and a 45% ammonium sulfate precipitation, MS and gMDH coeluted on Superdex 200 HR (low-ionic-strength buffer) as a complex with an approximate relative molecular mass (M(r)) of 670000. Dissociation was achieved in the presence of 50 mM KCl and 5 mM MgCl2, with the elution of MS as an octamer of M, 510 000 and of gMDH as a dimer of M, 73 000. Polyclonal antibodies raised to the native copurified enzymes recognized both denatured MS and gMDH on immunoblots, and their native forms after gel filtration. When these antibodies were used to screen a lambda ZAP II expression library containing cDNA from 3-d-old soybean cotyledons, they identified seven clones encoding gMDH, whereas ten clones encoding MS were identified using an antibody to SDS-PAGE-purified MS. Of these cDNA clones a 1.8 kb clone for MS and a 1.3-kb clone for gMDH were fully sequenced. While 88% identity was found between mature soybean gMDH and watermelon gMDH, the N-terminal transit peptides showed only 37% identity. Despite this low identity, the soybean gMDH transit peptide conserves the consensus R(X(6))HL motif also found in plant and mammalian thiolases.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: In published case reports, tocilizumab (TCZ) has shown good efficacy for AA amyloidosis in almost all patients. We investigated the efficacy and safety of TCZ in AA amyloidosis in a multicentre study of unselected cases. METHODS: We e-mailed rheumatology and internal medicine departments in France, Switzerland and North Africa by using the Club Rhumatismes Inflammation (CRI) network and the French TCZ registry, Registry RoAcTEmra (REGATE), to gather data on consecutive patients with histologically proven AA amyloidosis who had received at least one TCZ infusion. Efficacy was defined as a sustained decrease in proteinuria level and/or stable or improved glomerular filtration rate (GFR) and by TCZ maintenance. RESULTS: We collected 12 cases of AA amyloidosis treated with TCZ as monotherapy (mean age of patients 63 ± 16.2 years, amyloidosis duration 20.6 ± 31.3 months): eight patients had rheumatoid arthritis (RA), six with previous failure of anti-tumor necrosis factor α (anti-TNF-α) therapy. In total, 11 patients had renal involvement, with two already on hemodialysis (not included in the renal efficacy assessment). For the nine other patients, baseline GFR and proteinuria level were 53.6 ± 32.8 mL/min and 5 ± 3.3 g/24 h, respectively. The mean follow-up was 13.1 ± 11 months. TCZ was effective for six of the eight RA patients (87.5%) according to European League Against Rheumatism response criteria (four good and two moderate responders). As expected, C-reactive protein (CRP) level decreased with treatment for 11 patients. Renal amyloidosis (n = 9) progressed in three patients and was stabilized in three. Overall, three patients showed improvement, with sustained decrease in proteinuria level (42%, 82% and 96%). Baseline CRP level was higher in subsequent responders to TCZ than other patients (p = 0.02). Among the six RA patients with previous anti-TNF-α therapy, amyloidosis was ameliorated in one and stabilized in three. Three serious adverse events occurred (two diverticulitis and one major calciphylaxia due to renal failure). Finally, 7 of 12 (58%) patients continued TCZ. CONCLUSIONS: The efficacy of TCZ for AA amyloidosis varies depending on the inflammatory status at treatment onset. Discrepancies between our study of unselected consecutive patients and reported cases may be due to publication bias. These results support further prospective trials of TCZ for AA amyloidosis.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Cette rubrique présente les résultats d'une revue systématique récente telle que publiée dans la Cochrane Library (www.thecochranelibrary.com). Volontairement limité à un champ de recherche circonscrit, cet article reflète l'état actuel des connaissances de ce domaine. Il ne s'agit donc pas de recommandations pour guider la prise en charge d'une problématique clinique considérée dans sa globalité (guidelines). Les auteurs de ce résumé se basent sur la revue systématique et ne remettent pas en question le choix des articles inclus dans la revue. Scénario: Vous suivez un patient de 71 ans connu pour un diabète et une hypertension bien contrôlés, ainsi qu'une insuffisance rénale chronique de longue date, progressive, actuellement sévère (créatinine à 267 mmol/l, taux de filtration glomérulaire estimé (TFGe) à 21 ml/min/1,73 m2). Son état général est bon, son poids est stable et il ne présente pas de symptômes urémiques. Question: Faut-il adresser ce patient à un néphrologue ?

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The increase in seafood production, especially in mariculture worldwide, has brought out the need of continued monitoring of shellfish production areas in order to ensure safety to human consumption. The purpose of this research was to evaluate pathogenic protozoa, viruses and bacteria contamination in oysters before and after UV depuration procedure, in brackish waters at all stages of cultivation and treatment steps and to enumerate microbiological indicators of fecal contamination from production site up to depuration site in an oyster cooperative located at the Southeastern estuarine area of Brazil. Oysters and brackish water were collected monthly from September 2009 to November 2010. Four sampling sites were selected for enteropathogens analysis: site 1- oyster growth, site 2- catchment water (before UV depuration procedure), site 3 - filtration stage of water treatment (only for protozoa analysis) and site 4- oyster's depuration tank. Three microbiological indicators ! were examined at sites 1, 2 and 4. The following pathogenic microorganisms were searched: Giardia cysts, Cryptosporidium oocysts, Human Adenovirus (HAdV), Hepatitis A virus (HAV), Human Norovirus (HnoV) (genogroups I and II), JC strain Polyomavirus (JCPyV) and Salmonella sp. Analysis consisted of molecular detection (qPCR) for viruses (oysters and water samples); immunomagnetic separation followed by direct immunofluorescence assay for Cryptosporidium oocysts and Giardia cysts and also molecular detection (PCR) for the latter (oysters and water samples); commercial kit (Reveal-Neogee (R)) for Salmonella analysis (oysters). Giardia was the most prevalent pathogen in all sites where it was detected: 36.3%, 18.1%, 36.3% and 27.2% of water from sites 1, 2, 3 and 4 respectively; 36.3% of oysters from site 1 and 54.5% of depurated oysters were harboring Giardia cysts. The huge majority of contaminated samples were classified as Giardia duodenalis. HAdv was detected in water and o! ysters from growth site and HnoV GI in two batches of oysters ! (site 1) in huge concentrations (2.11 x 10(13), 3.10 x 10(12) gc/g). In depuration tank site, Salmonella sp., HAV (4.84 x 10(3)) and HnoV GII (7.97 x 10(14)) were detected once in different batches of oysters. Cryptosporidium spp. oocysts were present in 9.0% of water samples from site four. These results reflect the contamination of oysters even when UV depuration procedures are employed in this shellfish treatment plant. Moreover, the molecular comprehension of the sources of contamination is necessary to develop an efficient management strategy allied to shellfish treatment improvement to prevent foodborne illnesses. (C) 2011 Elsevier Ltd. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Ultrafiltration (UF) is widely applied in different separation processes in the pulp and paper industry. The growing need to protect the environment, a lack of pure water and an interest in producing high-value chemicals from compounds present in process waters will probably lead to an increase in the use of UF in the pulp and paper industry. The efficiency and cost-effectiveness of a UF process depends on the applied membrane. The membrane should have a high and stable filtration capacity, a particular selectivity and a long operational lifetime. To meet these requirements a membrane should have a low fouling tendency. In addition, it should withstand the prevailing operational and chemical conditions. This thesis evaluates the performance and applicability of the regenerated cellulose (RC) membranes 00030T and C2 in the treatment of pulp and paper mill process waters based on the requirements above. The results demonstrated that both the tested RC membranes fulfilled well the requirement of high filtration capacity. In addition, in the filtration of a paper mill clear filtrate (CF) the RC membranes were not as greatly affected by variations in the CF quality as a polysulphone membrane. Furthermore, due to their extreme hydrophilicity and weak charge the fouling tendency of the membranes can be expected to be low in pulp and paper mill filtration applications. It is, however, known that fouling cannot be totally avoided even when the membrane is chosen very carefully. This study indicated that carbohydrates influenced negatively on permeability and caused fouling in the filtration of groundwood mill circulation water. Thus, a pre-treatment effectively reducing the amount of carbohydrates might help to maintain a stable capacity. However, the results of the thesis also showed that the removal of some of the possible foulants might just increase the harmful effect of others. Multivariate examination was useful in the understanding of the complicated factors causing the unstable capacity. The thesis also revealed that the 00030T and C2 membranes can be used at high pressure (max. tested pressure 12 bar). The C2 membrane, having a sponge-like substructure, was more pressure resistant, and its performance was more stable at high pressure compared to the UCO30T membrane containing macrovoids in its substructure. Both tested membranes can, according to the results, also be used at temperatures as high as 70°C in acidic, neutral and alkaline conditions. However, the use at extreme conditions might cause faster ageing of the membranes compared to ageing in neutral conditions. The thesis proved that both the tested RC membranes are very suitable for pulp and paper mill applications and that the membranes can be utilised in processes operating in challenging conditions. Thus, they could be used in more demanding applications than supposed earlier.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this thesis the factors affecting lime mud filterability were studied. In the literature part there is information about recausticizing process, lime mud properties and filterability, and general filtration theory. In the experimental part the properties of lime mud particles and the properties of lime mud filter cake were investigated and the behavior of lime mud precoat was studied. The experiments were also carried out with R-PCC (rhombohedral precipitated calcium carbonate). The filtration and precoat studies were performed with a laboratory scale pressure filter. The pressure differences used were between 0.25-1.50 bars. Six different lime mud samples with varying amount of impurities and two R-PCC samples were used in the experiments. The average specific cake resistance of different lime mud samples varied quite extensively. The most influential factor affecting the lime mud filterability and dry solids content was found to be silica content. As the lime mud contained silica, the average specific cake resistance was high and the lime mud dryness was low. If the lime mud samples containing silica were not taken into account, the smaller the mean particle size, the higher the average specific cake resistance of the lime mud. The R-PCC had also a high average specific cake resistance, which was because of small particle size. In addition, the pressure difference affected the average specific cake resistance of some lime mud samples. In those cases lime mud was compressible material. During the precoat experiments the lime mud samples having the largest mean particle sizes, compressed. However, the average specific cake resistances of the filtration and precoat part were approximately the same magnitude. A brief displacement by air did not affect the behavior of the precoat. Instead, vibration and a brief but relatively great change in pressure difference had a slight influence.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: Antiretroviral regimens containing tenofovir disoproxil fumarate have been associated with renal toxicity and reduced bone mineral density. Tenofovir alafenamide is a novel tenofovir prodrug that reduces tenofovir plasma concentrations by 90%, thereby decreasing off-target side-effects. We aimed to assess whether efficacy, safety, and tolerability were non-inferior in patients switched to a regimen containing tenofovir alafenamide versus in those remaining on one containing tenofovir disoproxil fumarate. METHODS: In this randomised, actively controlled, multicentre, open-label, non-inferiority trial, we recruited HIV-1-infected adults from Gilead clinical studies at 168 sites in 19 countries. Patients were virologically suppressed (HIV-1 RNA <50 copies per mL) with an estimated glomerular filtration rate of 50 mL per min or greater, and were taking one of four tenofovir disoproxil fumarate-containing regimens for at least 96 weeks before enrolment. With use of a third-party computer-generated sequence, patients were randomly assigned (2:1) to receive a once-a-day single-tablet containing elvitegravir 150 mg, cobicistat 150 mg, emtricitabine 200 mg, and tenofovir alafenamide 10 mg (tenofovir alafenamide group) or to carry on taking one of four previous tenofovir disoproxil fumarate-containing regimens (tenofovir disoproxil fumarate group) for 96 weeks. Randomisation was stratified by previous treatment regimen in blocks of six. Patients and treating physicians were not masked to the assigned study regimen; outcome assessors were masked until database lock. The primary endpoint was the proportion of patients who received at least one dose of study drug who had undetectable viral load (HIV-1 RNA <50 copies per mL) at week 48. The non-inferiority margin was 12%. This study was registered with ClinicalTrials.gov, number NCT01815736. FINDINGS: Between April 12, 2013 and April 3, 2014, we enrolled 1443 patients. 959 patients were randomly assigned to the tenofovir alafenamide group and 477 to the tenofovir disoproxil fumarate group. Viral suppression at week 48 was noted in 932 (97%) patients assigned to the tenofovir alafenamide group and in 444 (93%) assigned to the tenofovir disoproxil fumarate group (adjusted difference 4·1%, 95% CI 1·6-6·7), with virological failure noted in ten and six patients, respectively. The number of adverse events was similar between the two groups, but study drug-related adverse events were more common in the tenofovir alafenamide group (204 patients [21%] vs 76 [16%]). Hip and spine bone mineral density and glomerular filtration were each significantly improved in patients in the tenofovir alafenamide group compared with those in the tenofovir disoproxil fumarate group. INTERPRETATION: Switching to a tenofovir alafenamide-containing regimen from one containing tenofovir disoproxil fumarate was non-inferior for maintenance of viral suppression and led to improved bone mineral density and renal function. Longer term follow-up is needed to better understand the clinical impact of these changes. FUNDING: Gilead Sciences.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Työssä selvitettiin suodatusolosuhteiden vaikutusta neutraalien polymeerien pidättymiseen niiden vesiliuoksia suodatettaessa. Suodatuksissa käytettiin kahta regeneroidusta selluloosasta valmistettua ultrasuodatuskalvoa (Microdyn-Nadir UC 030T ja JSC STC Vladipor C 30V). Malliaineina käytettiin polyetyleeniglykolia ja dekstraania. Kirjallisuusosassa esiteltiin aluksi lyhyesti ultrasuodatus erotusmenetelmänä. Lisäksi käsiteltiin ultrasuodatuskalvojen huokoskoon karakterisointimenetelmiä ja selvitettiin polymeerien erottumiseen ultrasuodatuksen aikana vaikuttavia tekijöitä. Työn kokeellisessa osassa tutkittiin paineen ja virtausnopeuden vaikutusta malliaineiden pidättymiseen ultrasuodatuskalvoilla. Lisäksi pyrittiin löytämään suodatusolosuhteet, joissa toinen aineista läpäisisi suodatuskalvon lähes täydellisesti toisen konsentroituessa syöttöliuokseen. Työssä myös määritettiin tutkimuksissa käytetyille kalvoille katkaisukoko, joka kuvaa kalvon kykyä pidättää moolimassaltaan erikokoisia molekyylejä. Lisäksi kokeellisessa osassa selvitettiin työssä käytettyjen kalvojen tasalaatuisuutta vertailemalla keskenään samanlaisissa suodatusolosuhteissa eri kalvopaloilla tehtyjen suodatusten tuloksia. Työssä saatiin erotettua kaksi lähes samankokoista malliaineeksi valittua neutraalia polymeeriä toisistaan siten, että toinen aine pidättyi kalvolla huomattavasti toista ainetta paremmin. Parhaimpaan erotustulokseen päästiin, kun permeaattivuo kalvon läpi oli noin 400 l/(m2 h). Tällöin suodatuspaine oli noin 2 bar ja virtausnopeus alle 2 m/s. Työn aikana määritettyjen katkaisukokojen havaittiin poikkeavan huomattavasti kalvojen valmistajien ilmoittamista arvoista, mutta olevan kuitenkin samaa suuruusluokkaa kuin muiden tutkimusryhmien vastaaville ultrasuodatuskalvoille esittämät arvot. Työn tulosten perusteella C 30V olisi hieman tasalaatuisempi kalvo kuin UC 030T.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Reduced glomerular filtration rate defines chronic kidney disease and is associated with cardiovascular and all-cause mortality. We conducted a meta-analysis of genome-wide association studies for estimated glomerular filtration rate (eGFR), combining data across 133,413 individuals with replication in up to 42,166 individuals. We identify 24 new and confirm 29 previously identified loci. Of these 53 loci, 19 associate with eGFR among individuals with diabetes. Using bioinformatics, we show that identified genes at eGFR loci are enriched for expression in kidney tissues and in pathways relevant for kidney development and transmembrane transporter activity, kidney structure, and regulation of glucose metabolism. Chromatin state mapping and DNase I hypersensitivity analyses across adult tissues demonstrate preferential mapping of associated variants to regulatory regions in kidney but not extra-renal tissues. These findings suggest that genetic determinants of eGFR are mediated largely through direct effects within the kidney and highlight important cell types and biological pathways.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

OBJECTIVE: Periodic limb movements during sleep (PLMS) are sleep phenomena characterized by periodic episodes of repetitive stereotyped limb movements. The aim of this study was to describe the prevalence and determinants of PLMS in a middle to older aged general population. METHODS: Data from 2,162 subjects (51.2% women, mean age = 58.4 ± 11.1 years) participating in a population-based study (HypnoLaus, Lausanne, Switzerland) were collected. Assessments included laboratory tests, sociodemographic data, personal and treatment history, and full polysomnography at home. PLMS index (PLMSI) was determined, and PLMSI > 15/h was considered as significant. RESULTS: Prevalence of PLMSI > 15/h was 28.6% (31.3% in men, 26% in women). Compared to subjects with PLMSI ≤ 15/h, subjects with PLMSI > 15/h were older (p < 0.001), were predominantly males (p = 0.007), had a higher proportion of restless legs syndrome (RLS; p < 0.001), had a higher body mass index (p = 0.001), and had a lower mean glomerular filtration rate (p < 0.001). Subjects with PLMSI > 15/h also had a higher prevalence of diabetes, hypertension, and beta-blocker or hypnotic treatments. The prevalence of antidepressant use was higher, but not statistically significant (p = 0.07). Single nucleotide polymorphisms (SNPs) within BTBD9 (rs3923809), TOX3 (rs3104788), and MEIS1 (rs2300478) genes were significantly associated with PLSMI > 15/h. Conversely, mean hemoglobin and ferritin levels were similar in both groups. In the multivariate analysis, age, male gender, antidepressant intake, RLS, and rs3923809, rs3104788, and rs2300478 SNPs were independently associated with PLMSI > 15/h. INTERPRETATION: PLMS are highly prevalent in our middle-aged European population. Age, male gender, RLS, antidepressant treatment, and specific BTBD9, TOX3, and MEIS1 SNP distribution are independent predictors of PLMSI > 15/h. ANN NEUROL 2016;79:464-474.